LSD1 增殖 迁移 侵染

Over-Expression of LSD1Promotes Proliferation, Migration and Invasion in Non-Small Cell Lung Cancer Tangfeng Lv1,Dongmei Yuan1,Xiaohui Miao1,Yanling Lv1,Ping Zhan2,Xiaokun Shen1,Yong Song1*

1Department of Respiratory Medicine,Jinling Hospital,Nanjing University School of Medicine,Nanjing,China,2First Department of Respiratory Medicine,Nanjing Chest Hospital,Nanjing,China

Abstract

Background:Lysine specific demethylase1(LSD1)has been identified and biochemically characterized in epigenetics,but the pathological roles of its dysfunction in lung cancer remain to be elucidated.The aim of this study was to evaluate the prognostic significance of LSD1expression in patients with non-small cell lung cancer(NSCLC)and to define its exact role in lung cancer proliferation,migration and invasion.

Methods:The protein levels of LSD1in surgically resected samples from NSCLC patients were detected by immunohistochemistry or Western blotting.The mRNA levels of LSD1were detected by qRT-PCR.The correlation of LSD1expression with clinical characteristics and prognosis was determined by statistical analysis.Cell proliferation rate was assessed by MTS assay and immunofluorescence.Cell migration and invasion were detected by scratch test,matrigel assay and transwell invasion assay.

Results:LSD1expression was higher in lung cancer tissue more than in normal lung tissue.Our results showed that over-expression of LSD1protein were associated with shorter overall survival of NSCLC patients.LSD1was localized mainly to the cancer cell nucleus.Interruption of LSD1using siRNA or a chemical inhibitor,pargyline,suppressed proliferation,migration and invasion of A549,H460and293T cells.Meanwhile,over-expression of LSD1enhanced cell growth.Finally,LSD1was shown to regulate epithelial-to-mesenchymal transition in lung cancer cells.

Conclusions:Over-expression of LSD1was associated with poor prognosis in NSCLC,and promoted tumor cell proliferation, migration and invasion.These results suggest that LSD1is a tumor-promoting factor with promising therapeutic potential for NSCLC.

Citation:Lv T,Yuan D,Miao X,Lv Y,Zhan P,et al.(2012)Over-Expression of LSD1Promotes Proliferation,Migration and Invasion in Non-Small Cell Lung Cancer.PLoS ONE7(4):e35065.doi:10.1371/journal.pone.0035065

Editor:Pan-Chyr Yang,National Taiwan University Hospital,Taiwan

Received November22,2011;Accepted March11,2012;Published April6,2012

Copyright:?2012Lv et al.This is an open-access article distributed under the terms of the Creative Commons Attribution License,which permits unrestricted use,distribution,and reproduction in any medium,provided the original author and source are credited.

Funding:The authors have no support or funding to report.

Competing Interests:The authors have declared that no competing interests exist.

*E-mail:yong_song6310@https://www.wendangku.net/doc/7215060609.html,

Introduction

Lung cancer is one of the leading causes of cancer death worldwide.Non-small cell lung cancer(NSCLC)is the most common type of lung cancer[1].The5-year survival rate for lung cancer remains poor.In order to develop more effective therapies, it is important to obtain a better understanding of the molecular biology of lung cancer.

Genetic alterations are a hallmark of human cancer.In recent years,the cancer genomics field has made significant advances in identifying genetic lesions in cancer.Furthermore,the importance of epigenetic changes that occur during lung cancer development has also been recognized[2].Epigenetic changes are associated with both DNA methylation and histone modifications[3]. Histone modifications,such as acetylation,phosphorylation and methylation,are the switches that alter chromatin structure to allow posttranscriptional activation or repression of downstream proteins[4].Understanding these epigenetic changes will identify novel cancer-related genes that may represent attractive targets for cancer treatment and provide new insights into the biology of lung combining epidemiological,genetic and epigenetic information, has emerged as an important concept for cancer therapy[5]. The methylation status of histone methyltransferases and histone demethylases plays a pivotal role in the regulation of gene expression[6].Histone demethylase lysine specific demethylase1 (LSD1),the first histone demethylase that was discovered as a nuclear homolog of amine oxidases,removes the methyl groups from mono-and dimethylated Lysine(Lys)4of histone H3 (H3K4me1/2)and Lys9of histone H3(H3K9me1/2)[7].LSD1 is essential for mammalian development and involved in many biological processes,such as cell-type differentiation and gene activation and repression[8].A recent study indicated that LSD1 might promote cell phase transition(deficiency in LSD1led to partial cell cycle arrest in G2/M)and cell proliferation,suggesting that its over-expression might promote tumorigenesis[9].The expression of LSD1has been associated with tumor recurrence during therapy in various cancers,further implicating LSD-1as a tumor promoter[10–12].Tissue cDNA microarray analysis also revealed LSD1transactivation in lung and colorectal carcinomas

resulted in suppression of proliferation of various bladder and lung cancer cell lines[11].However,although these studies demon-strated that LSD1may be associated with the pathogenesis of lung cancer,the expression and significance of LSD1in NSCLC is obscure.

In this study,we attempted to investigate the expression and function of LSD1in NSCLC,its relationship with clinicopatho-logical features,and its prognostic value for survival of patients with NSCLC.Finally,we also aimed to determine the exact role of LSD1in lung cancer proliferation,migration and invasion. Materials and Methods

Patients and Specimens

Surgical specimens from80NSCLC patients obtained at the Nanjing Chest Hospital and the Jinling Hospital from January 2001to December2003were retrospectively collected for study. These consisted of38squamous carcinomas and42adenocarci-nomas,along with patient-matched adjacent non-tumor tissue specimens.None of the patients had received radiotherapy or chemotherapy prior to surgery.All patients had been followed-up for five years after operation,and complete clinical data were electronically recorded.All tumor tissues were classified according to the World Health Organization classification guidelines.The staging of the tumors followed the7th Union International Classification at Cancer criteria defined in2009.This study was approved by the Ethical Committee of the Jinling Hospital at Nanjing.All samples were anonymized,and none of the researchers conducting the experiments had access to the clinicopathological data.

Immunohistochemical(IHC)Staining

All samples were fixed in10%formalin,embedded in paraffin, sectioned consecutively at5m m,and stained by hematoxylin and eosin.The sections were deparaffinized and rehydrated according to routine protocol.The sections were incubated for overnight with the specific primary LSD1antibodies(1:100dilution;Cell Signaling, Danvers,MA,USA).The slides were incubated for30min with goat anti-rabbit immunoglobulins(E0432;Cell Signaling)after being washed with Tris-buffered NaCl solution.The slides were then incubated for30min with stripped AB complex/AP(K0391;Dako, Peking,China).Counterstaining was performed with hematoxylin. The percentage of positive cells was determined by counting500cells in five random areas per section.Nuclear immunostaining results for LSD1were evaluated using a semi-quantitative Remmele scoring system[13],which calculated the staining intensity and the percentage of positive cells.IHC staining was scored according to the following criteria:–,none of the cells stained;+,1–40%of the cells stained;++;40–70%of the cells stained;+++,70–100%of the cells stained.IHC score of LSD1expression was[0(negative)#score, 2+]and[2+#score#3+],which represented low and high expression,respectively.

Western Blotting

The lung cancer tumor tissues and adjacent non-tumor tissues were homogenized.Total proteins(30m g)from clinical specimens or cell cultures were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis,followed by electrotransfer to a nitrocellulose membrane by use of a transfer cell(Bio-Rad, Hercules,CA,USA).Western blotting was carried out by sequential incubation in5%non–fat milk blocking buffer at room temperature for60min,followed by primary antibody against either LSD1(1:500;Cell Signaling),AcH3K9,Twist1,E-cadherin,peroxidase-conjugated anti-rabbit secondary antibody(1:5000)at room temperature for90min.Immunoreactive bands were detected by reaction with the ECL detection system reagents (Amersham,Arlington Heights,IL,USA)and exposure to X-ray film,which was the developed and photographed.

mRNA Extraction and Quantitative Reverse Transcription (qRT)-PCR

Tissues were homogenized and total cellular mRNA was isolated using the TRIzol reagent(Invitrogen,Carlsbad,CA, USA).The cDNA was transcribed using M-MLV reverse transcriptase(Promega,Madison,WI,USA),according to the manufacturer’s protocol.qRT-PCR was performed using the FastStart Universal SYBR Green Master Mix kit(Roche,San Francisco,CA,USA).Relative mRNA levels of LSD1were normalized to levels of the housekeeping gene GAPDH and calculated by the2-DD Ct method.The following primers were used:GAPDH,forward:5’-CCATGTTCGTCATGGGTGT-GAACCA-3’and reverse:5’-GCCAGTAGAGGCAGGGAT-GATGTTG-3’;LSD1,forward:5’-GAAACTGGAATAGCAGA-GAC-3’and reverse:5’-GGTGGACAAAGCACAGTATCA-3’. Cell Culture,Transfection and Treatment

A549,H460,and293T cells were obtained from the American Type Culture Collection(Manassas,VA,USA)and cultured in RPMI medium supplemented with10%fetal bovine serum(FBS), 2mM L-glutamine and100m g/mL penicillin/streptomycin.The plasmid Flag-LSD1(3ug);kindly provided by Dr.Yang Shi, University of Southern California,Los Angeles,CA,USA),over-expression plasmid LSD1(3m g)and LSD1siRNA(3m g)were transfected into A549and H460cell lines in6-well plates(1m g/ mL)using the Lipofectamine reagent(Invitrogen),according to the manufacturer’s instructions.Pargyline(Sigma-Aldrich,St.Louis, MO,USA),a monoamine oxidase inhibitor,was used to chemically block LSD1-mediated demethylation[14].Cells were treated with pargyline for48h,and then were subjected to MTS assay.The data are presented as fold-changes in relative light units/milliunits of pargyline,and represent the average of three independent experiments.

Cell Proliferation,Growth,MTS Assays

For cell growth assay,50,000cells/well were seeded in triplicate in a24-well plate with complete growth medium.Cells were counted over six days using a hemocytometer.For the MTS assay (Promega),500cells/well were seeded in triplicate in a96-well plate for each cell line.At12,24,and48h,20m L of MTS reagent was added to each well,incubated for1h at37u C,and the results were analyzed by a plate reader at490nm.The sample data was normalized to background readings of media only.

Three-dimensional Cell Culture,Collagen Invasion Assay, and Scratch Assay

Three-dimensional basement membrane cultures were estab-lished as previously described[15].Briefly,5000cells/well were grown in2%matrigel(BD Biosciences,San Jose,CA,USA)with epidermal growth factor(EGF)on a50%matrigel base layer.The collagen invasion assay was performed as previously described [16].Briefly,5000cells/well were seeded in2%matrigel on a layer of1:1collagen(BD Bioscience)to matrigel mix.Culture growth was recorded on day5.For the scratch assay,cells were grown in complete growth medium until90–100%confluency was reached. A3mm wound was introduced across the diameter of each plate.

Statistical Analysis

Student’s t -test and ANOVA were used to investigate the associations between LSD1expression and clinical factors (age,sex,smoking,tumor stage,histology,tumor size,nodal status,

and overall survival).Pearson’s correlation analysis was used to evaluate the degree of linear correlation between two variables.Kaplan-Meier survival analysis was performed to determine the prognostic value of LSD1,and log-rank test was used to

compare

Figure 1.LSD1expression and distribution in NSCLC tumor tissues and normal lung tissues,detected by IHC staining.(A,B)LSD1expression was up-regulated in lung squamous cancer tissue.The arrows indicate LSD1-positive cancer cells,which were located in the cell nuclei.Magnification:A,620;B,660.(C,D)LSD1expression was up-regulated in lung adenocarcinoma cancer tissue.Magnification:C,620;D,660.(E,F)IHC revealed that LSD1expression was weak in normal lung tissues.Magnification:E,620;F,660.IHC scores of LSD1expression were:low,[0(negative)#score ,2+];high,[2+#score #3+].P ,0.05indicated statistically significant differences between groups.

doi:10.1371/journal.pone.0035065.g001

Figure 2.Up-regulation of LSD1expression in NSCLC tumor tissues.(A)The protein level of LSD1in lung cancer tissue was significantly higher than in normal tissue (P ,0.01),as detected by Western blot.b -tubulin was used as a loading control.(B)Sample 122,206and 207are shown as representatives of the three groups:N,normal lung tissues:C,NSCLC tissues;P,paracarcinoma tissues.(C)The mRNA level of LSD1was detected by qRT-PCR,and the mRNA expression of LSD1was significantly higher in tumor tissue than in normal tissue (P ,0.05).

the equality of the two survival curves.A P -value ,0.05was considered statistically significant and P ,0.01was considered highly significant.All statistical analyses were performed using the SPSS program v17.0for Windows (SPSS,Chicago,IL,USA).

Results

LSD1Expression was Up-regulated in NSCLC Tumor Tissues

We first examined expression levels of LSD1in 80NSCLC tumor tissues and 20normal lung tissues by IHC staining.High LSD1expression was detected in the nuclei of malignant cells,while weak staining was observed throughout the non-neoplastic tissues (Fig.1).Specifically,the expression of LSD1was observed in 90.0%of lung carcinomas (72/80)and 10.0%of benign lung specimens (2/20).High levels of LSD1expression (score:++-+++)were detected in 37(46.3%)tumor tissues from NSCLC patients.We next examined LSD1expression in 40randomly selected NSCLC tumor tissues,paracarcinoma lung tissues,and normal lung tissues by Western blotting.The results revealed a statistically significant elevation of LSD1expression in tumors,as compared to the normal lung tissues using b -tubulin as the reference (two-tailed paired t -test,n =40,P ,0.01)(Fig.2A).The protein level of LSD1in samples 122,206,and 207is shown in Figure 2B.

To further validate the above protein results,we also examined the mRNA levels of LSD1in these 40selected NSCLC tumor tissues and normal lung tissues by qRT-PCR using GAPDH as reference.We found that the mRNA level of LSD1in cancer tissues (Ct =19.961.01)was significantly higher than that in normal lung tissues (Ct =22.160.9)(two-tailed paired t -test,n =40,P ,0.05)(Fig.2C).

LSD1Expression was Associated with Overall Survival

To evaluate the clinical significance of LSD1over-expression in lung cancer,we analyzed whether expression levels of LSD1were associated with overall survival in NSCLC.As shown Table 1,high protein levels of LSD1were significantly associated with survival (x 2=12.87,P =0.0003),but not correlated with any of the clinicopathologic characteristics (including age,smoking habits,sex,tumor diameter,histologic type,visceral pleural invasion,pathologic stage,or type of operation;all,P .0.05).During the 5-year follow-up period,52out of 80(65%)NSCLC patients died as a result of disease progression.Kaplan–Meier curves indicated that patients with increased LSD1expression (28cases)had a significantly shorter overall survival than those with decreased LSD1expression (52cases)(P =0.0003)(Fig.3A).

In agreement with this,we also determined that higher mRNA expression of LSD1was associated with decreased overall survival in NSCLC patients (P ,0.05)(Fig.3B.).

Table 1.Statistical analysis of LSD1expression levels in clinical lung tissues.

LSD1Factor Cases,n Negative Low High x 2P Age,years 801043270.007

0.934

,603832213$6042

7

21

14

Gender 0.553

0.460

Male 61103120Female 19

11

8

Smoker 0.760

0.180

No 4122117Yes 39

8

20

11

Histology 0.007

0.934

Squamous carcinoma 3861913Adenocarcinoma 42

7

21

14

Pathological stage 0.030

0.870

T ,3cm 181116T $3cm 62

9

31

22

Nodal status 0.005

0.940

N04962617N1-231

4

16

11

OS,months 12.870

0.0003

#121426612–3627381636–6011254.60

28

2

24

2

doi:10.1371/journal.pone.0035065.t001

Figure 3.LSD1expression was associated with overall survival in NSCLC.Blue lines depict high levels of LSD1expression,and red lines depict low levels of LSD1expression in NSCLC samples.(A)NSCLC patients with lower LSD1protein levels had better prognosis.(unadjusted P -value =0.0003;low expression cases,n =52and high expression cases,n =28).(B)Patients with lower mRNA levels of LSD1also had longer survival (P ,0.05).

LSD1Promoted Proliferation in Lung Cancer Cell Lines

The expression of LSD1was lower in the A549cell than in the H460cell line,as shown in Figure 4.Therefore,the Flag-LSD1plasmid was transfected into the A549cells and the LSD1siRNA

plasmid was transfected into the H460cells.The 293T normal epithelial cells were used as a negative control.

We detected the OD value of A549,H460and 293T cells by MTS to generate cell growth curves.In all three cell lines,the cellular proliferation declined along with pargyline treatment in a concentration-dependent manner.It was notably lower in the 4mM-treated group than in the 1mM-or 2mM-treated groups.In addition,it was also lower in the 1mM-treated group than in the 3mM-treated group;however,there was no difference between the 1mM-and 2mM-treated groups or the 3mM-and 4mM-treated groups (P .0.05),as shown in Figure 5A-C.The proliferation significantly increased in the A549group after transfection of the Flag-LSD1plasmid (P ,0.05);however,it significantly decreased in the H460group after transfection of the LSD1siRNA plasmid (P ,0.05).The pCMV plasmid was used as the control in the A549transfection group,and the LSD1siRNA control plasmid was used in the H460cell transfection group (Fig.5D).

We further identified the role of LSD1in A549and H460cell proliferation by immunofluorescence staining.The change in number of proliferating cells was observed by BrdU staining.The results demonstrated that the cell proliferation was

significantly

Figure 4.Expression of LSD1in A549,H460and 293T cells.The expression of LSD1in the A549and H460lung cancer cells was higher than in the 293T cells.The protein level in the H460cell line was higher than that in the A549cell line.b -actin was used as loading control.

doi:10.1371/journal.pone.0035065.g004

Figure 5.The proliferation curve of A549,H460and 293T cell lines after pargyline treatment and transfection of Flag-LSD1or LSD1siRNA.The series of curves represent cell proliferation at 0h to 48h after exposure to different concentrations of pargyline treatment and transfection with the different plasmids.(A)The LSD1inhibitor,pargyline (from top to bottom:1mM,2mM,3mM and 4mM),and LSD1siRNA inhibited proliferation of the A549cell line.The A549cell proliferation was significantly decreased in the different groups,as compared to the controls (*P ,0.05).(B)Pargyline inhibited H460cell line survival.Moreover,a stronger inhibitory effect was observed in the H460cell line,but there were no significant differences between the two cell lines.The H460cell proliferation was significantly decreased in the different concentration groups,as compared to the controls (*P ,0.05).(C)Pargyline inhibited the survival of the 293T cell line.(D)The proliferation curve after transfection of Flag-LSD1plasmid into the A549cell and transfection of LSD1siRNA plasmid into the H460cell.In A549cells,the proliferation was significantly higher after transfection of the Flag-LSD1plasmid,as compared to the pCMV5-transfected control (*P ,0.05).In H460cells,the proliferation was significantly lower after transfection of LSD1the siRNA plasmid,as compared to the cells transfected with siRNA control plasmid (*P ,0.05).

increased after transfection of the over-expressing LSD1plasmid into the A549cell line.Meanwhile,cell proliferation decreased in the H460cells transfected with the LSD1siRNA plasmid.It decreased in both cell lines after pargyline treatment,as shown by immunofluorescence staining (Fig.6),which also confirmed that LSD1is involved in tumor cell proliferation.

LSD1Promoted the Migration of Lung Cancer Cells

Cell migration was investigated by the cell scratch https://www.wendangku.net/doc/7215060609.html,pared with the control group,the number and rate of migrated cells was gradually reduced after transfection with LSD1siRNA plasmid in the H460cell lines.The migrating cells reached

a peak at 48h,as shown in Figure 7A.In contrast,the number of migrated cells were significantly increased in the A549cell line after transfection with Flag-LSD1plasmid,as compared to the control group (P ,0.05).The relative speed of migration is shown in Figure 7B.

The Role of LSD1in Lung Cancer Invasion

The ability of cells to cross matrigel indicated the invasiveness of the A549and H460cell lines.H460cells transfected with LSD1siRNA plasmid were less invasive than the control group (P ,0.05).A549cells transfected with Flag-LSD1plasmid were more

invasive

Figure 6.Changes in LSD1activity affect cell proliferation in the A549and H460cell lines,as detected by immunofluorescence.Images are shown at 620magnification.Green,red and blue fluorescence represent LSD1,BrdU and Topro-3,respectively.The proliferation significantly increased in the A549cells after transfection of the Flag-LSD1plasmid.However,proliferation decreased in the H460cells after transfection of the LSD1siRNA plasmid.Pargyline treatment reduced proliferation in both cell lines.Topro-3staining shows nuclear localization,and BrdU staining shows the proliferating cells.

doi:10.1371/journal.pone.0035065.g006

Figure 7.The relative velocity change of cell migration in A549and H460cells transfected with Flag-LSD1or LSD1siRNA plasmid,respectively.The migration velocity gradually decreased from 6h to 48h after transfection of the LSD1siRNA plasmid in the H460cells,which was significantly different from the velocity at 24h and 48h (*P ,0.05).The migration rate gradually increased after transfection of Flag-LSD1plasmid into the A549cells,which was significantly different from the velocity at 24h and 48h (*P ,0.05).All transfection groups were significant different from the control groups (*P ,0.05).

than the control cells and cells treated with pargyline (both,P ,0.05).The amount of invading cells crossing through the matrigel basement membrane is shown in Figure 8.

LSD1Regulated Epithelial-to-mesenchymal Transition (EMT)in Lung Cancer Cells

To investigate whether LSD1regulates the EMT transition in lung cancer cells,we examined the expression of the key EMT transcriptional repressor TWIST1and the EMT markers E-cadherin and N-cadherin in LSD1-over-expressing A549cells (transfected with the Flag-LSD1LSD1over-expressing plasmid)and LSD1knocked down H460cells (transfected with the LSD1siRNA plasmid,or treated with 4mM pargyline).The effects on H3K9,AcH3K9,Twist1,E-cadherin and N-cadherin expression induced by alteration of the LSD1activity were examined.While expression of total H3K9was unaffected,LSD1over-expression led to decreases in H3K9acetylation and E-cadherin expression and increases in Twist1and N-cadherin expression.Meanwhile,H3K9acetylation levels and E-cadherin expression were increased in LSD1knock down cells,suggesting that LSD1expression might be correlated with AcH3K9,Twist1,E-cadherin and N-cadherin expression,as shown in Figure 9.

Discussion

In recent years,epigenetics has become a hot topic in cancer research.The balance of methylation and demethylation in epigenetic modification affects gene expression and cellular activity.Studies have demonstrated that aberrant histone lysine methylation in cancer is associated not only with the repression of chromatin related to specific genes,but also with the repression of large chromosomal regions.Epigenetic changes in LSD1have been shown to play a key role in carcinogenesis [17].LSD1can prevent the accumulation of the dimethyl groups of p53,repressing p53-mediated transcriptional up-regulation,preventing apoptosis,and contributing to human carcinogenesis via a chro-matin modification mechanism.

To date,only a few studies have implicated LSD1in NSCLC.cantly knocked down LSD1expression and resulted in suppressed proliferation of various lung cancer cells [11].However,the association between LSD1and the survival of NSCLC patients was not well defined,and the role of LSD1in proliferation,migration and invasion in NSCLC was obscure.Our study investigated the associations of LSD1expression and clinical features of NSCLC patients diagnosed as stage I/II.In order to demonstrate that the epigenetic changes were associated with genetic changes in lung cancer,we first investigated the expression of LSD1in NSCLC clinical samples.

Previous studies demonstrated that LSD1protein and mRNA levels could act as biomarkers for patients with more aggressive tumors of breast cancer,prostate cancer,and neuroblastoma [18–20].In our study,we detected LSD1by IHC analysis,Western blotting,and qRT-PCR.A strong point of this research is the finding that expression of LSD1was significantly correlated with overall survival of NSCLC patients.Our current research investigated the role of LSD1in NSCLC.Further studies on LSD1in other tumor types may reveal that patients with higher levels of LSD1(regardless of mRNA or protein and/or regardless of primary tumor type)have poorer survival than patients with lower levels of LSD1.

We further demonstrated that LSD1was important for cancer cell proliferation and invasion.LSD1-induced activation of proliferation,migration and invasion in tumor cell was inhibited by pargyline.Down-regulation of LSD1expression by siRNA in tumor cell lines led to increased cell growth,migration and invasion.These data suggest that LSD1may influence the transformation of tumor cells and may also promote EMT in the lung epithelium.Further research needs to be conducted in order to determine whether over-expression of LSD1is an early or late event in lung tumorigenesis and what the mechanism of over-expression is.We have presented data suggesting that LSD1is up-regulated in the lung cancer tumor promotion pathway and that it acts to increase cell growth,migration and invasion,and to restore a transformed epithelial phenotype.Pharmacological suppression of LSD1may represent a promising approach for NSCLC

Figure 8.The numbers of A549and H460cells that transversed the matrigel basement membrane.The transversed cell amount was significantly higher for A549cells transfected with the Flag-LSD1plasmid;however,transfection of LSD1siRNA plasmid into the H460cells led to decreased amounts of invasive cells.The numbers of invasive cells from both transfection groups were significant different from the control group (*P ,0.05).

doi:10.1371/journal.pone.0035065.g008

Figure 9.Changes in LSD1activity affect AcH3K9,Twist1,E-cadherin and N-cadherin expression in A549and H460cells.The expression of total H3K9did not change remarkably.When LSD1activity was up-regulated,Twist1and N-cadherin expression increased and AcH3K9and E-cadherin expression decreased.When LSD1activity was down-regulated,Twist1and N-cadherin expression decreased and AcH3K9and E-cadherin expression increased.The Flag-LSD1plasmid was transfected into the A549cell line,and the LSD1siRNA plasmid was transfected into the H460cell line.b -actin was used as loading control.doi:10.1371/journal.pone.0035065.g009

Further functional analysis is required to determine the regulatory network of LSD1.Transcriptional analysis revealed that the LSD1/NuRD complexes regulate several cellular signaling pathways[21],including the TGF b1signaling pathway that is critically involved in cell proliferation,survival,and epithelial-to-mesenchymal transition.We demonstrated that LSD1promoted the invasion and metastatic potential of lung cancer cells in vitro.We also found that LSD1is up-regulated in lung carcinomas and that its level of expression is negatively correlated with that of AcH3K9,Twist1and N-cadherin,and positively correlated with that of E-cadherin.Our data provide a molecular basis for the interplay of histone deacetylation in chromatin remodeling,indicating that LSD1may affect the EMT and acetylation of H3K9.

The aberrant over-expression of LSD1in lung cancer may make it a good candidate as a therapeutic molecular target[11]. This kind of information also indicates that we should carry on the development of novel anticancer therapy based on epigenetic status.As it has implications for the discovery of epigenetic markers,an important question to resolve is how to define potential targets for epigenetic therapy.First-generation drugs targeting the relatively promiscuous DNA methylation and histone acetylation modifiers have had success in the treatment of hematological cancers[22].If LSD1inhibition leads to significant de-repression of some genes,LSD1might be an important alternative target for therapy.Epigenetic control of gene regulation is a rapidly developing field with substantial potential,and oncology is likely to be the therapeutic application in which the fastest progress is made.To date,synthetic inhibitors of classical histone deacetylases have been widely used as biological tools for epigenetic studies,and some have advanced to clinical studies.In addition,development of histone methyltransferase and demethylase inhibitors has recently been reported[21,23].In lung cancer,over-expression of LSD1should contribute to gene repression to inhibit cellular growth and malignant progression, but where there is an actual purpose of LSD1remains unknown. We plan to investigate this in future studies.

In conclusion,we found that LSD1was over-expressed in NSCLC patients,through early to late stages of carcinogenesis. LSD1is present in the nucleus and promotes proliferation, possibly through regulation of a wide variety of chromatin functions.Meanwhile,over-expression of LSD1promoted tumor cell proliferation,migration and invasion.Further validation with functional analyses of this protein in the context of human carcinogenesis may assist in development of novel therapeutic strategies for lung cancer.

Author Contributions

Conceived and designed the experiments:TFL XHM YS.Performed the experiments:TFL XHM YLL PZ XKS.Analyzed the data:TFL DMY XHM YLL YS.Contributed reagents/materials/analysis tools:TFL PZ XKS YS.Wrote the paper:TFL DMY XHM YS.

References

1.Jemal A,Siegel R,Xu J,Ward E(2010)Cancer statistics,2010.CA Cancer J Clin

60:277–300.

2.Piperi C,Vlastos F,Farmaki,Martinet N,Papavassiliou AG(2008)Epigenetic

effects of lung cancer predisposing factors impact on clinical diagnosis and prognosis.J Cell Mol Med12:1495–1501.

3.Seligson DB,Horvath S,McBrian MA,Mah V,Yu H,et al.(2009)Global levels

of histone modifications predict prognosis in different cancers.Am J Pathol174: 1619–1628.

4.Yang S(2007)Histone lysine demethylases:emerging roles in development,

physiology and disease.Nature Reviews,Genetics8:829–833.

5.Risch A,Plass C(2008)Lung cancer epigenetics and genetics.Int J Cancer123:

1–7.

6.Ueda R,Suzuki T,Mino K,Tsumoto H,Nakaqawa H,et al.(2009)

Identification of Cell-Active Lysine Specific Demethylase1-Selective Inhibitors.

J Am Chem Soc131:17536–17537.

7.Shi Y,Lan F,Matson C,Mulliqan P,Whetstine JR,et al.(2004)Histone

demethylation mediated by the nuclear amine oxidase homolog LSD1.Cell119: 941–953.

8.Wang J,Scully K,Zhu X,Cai L,Zhang J,et al.(2007)Opposing LSD1

complexes function in developmental gene activation and repression pro-grammes.Nature446:882–887.

9.Scoumanne A,Chen X(2007)The lysine-specific demethylase1is required for

cell proliferation in both p53-dependent and-independent manners.J Biol Chem282:15471–15475.

10.Lim S,Janzer A,Becker A(2010)Lysine-specific demethylase1(LSD1)is highly

expressed in ER-negative breast cancers and a biomarker predicting aggressive biology.Carcinogenesis31:512–520.

11.Hayami S,Kelly JD,Cho HS,Yoshimatsu M,Unoki M,et al.(2011)

Overexpression of LSD1contributes to human carcinogenesis through chromatin regulation in various cancers.Int J Cancer128:574–586.12.Chen PP,Li WJ,Wang Y,Zhao S,Li DY,et al.(2007)Expression of Cyr61,

CTGF,and WISP-1correlates with clinical features of lung cancer.PLoS One 2:e534.

13.Remmele W,Stegner HE(1987)Recommendation for uniform definition of an

immunoreactive score(IRS)for immunohistochemical estrogen receptor detection(ER-ICA)in breast cancer tissue.Pathologe8:138–140.

14.Metzger E,Wissmann M,Yin N,Mu¨ller JM,Schneider R,et al.(2005)LSD1

demethylates repressive histone marks to promote androgen-receptor-dependent transcription.Nature37:436–439.

15.Debnath J,Muthuswamy SK,Brugge JS(2003)Morphogenesis and oncogenesis

of MCF-10A mammary epithelial acini grown in three-dimensional basement membrane cultures.Methods30:256–268.

16.Xiang B,Muthuswamy SK(2006)Using three-dimensional acinar structures for

molecular and cell biological assays.Methods Enzymol406:692–701.

17.Lim S,Metzger E,Schu¨le R,Kirfel J,Buettner R(2010)Epigenetic regulation of

cancer growth by histone demethylases.Int J Cancer127:1991–1998.

18.Lim S,Janzer A,Becker A,Zimmer A,Schu¨le R,et al.(2010)Lysine-specific

demethylase1(LSD1)is highly expressed in ER-negative breast cancers and

a biomarker predicting aggressive biology.Carcinogenesis31:512–520.

19.Schulte JH,Lim S,Schramm A,Friedrichs N,Koster J,et al.(2009)Lysine-

specific demethylase1is strongly expressed in poorly differentiated neuroblas-toma:implications for therapy.Cancer Res69:2065–2071.

20.Suikki HE,Kujala PM,Tammela TL,van Weerden WM,Vessella RL,et al.

(2010)Genetic alterations and changes in expression of histone demethylases in prostate cancer.Prostate70:889–898.

21.Wang Y,Zhang H,Chen Y,Sun Y,Yang F,et al.(2009)LSD1is a subunit of

the NuRD complex and targets the metastasis programs in breast cancer.Cell 138:660–672.

22.Best JD,Carey N(2010)Epigenetic opportunities and challenges in cancer.

Drug Discov Today15:65–70.

23.Cole PA(2008)Chemical probes for histone-modifying enzymes.Nat Chem Biol

4:590–597.

动物的迁徙行为

摘要 动物迁徙是大自然界存在的一中普遍现象，引 发的原因以及种类也有很多。动物的大规模的 迁徙也给自然界的人类带来了许多的变化和 反思，地球资源的枯竭和大气环境的日益变 化，都给动物们带来了许多的威胁的危险，所 以我们人类一定要时刻敲响着警钟，重视研究 动物引起迁徙的原因，虽然还有太多的未解之 谜，但是还是值得我们一起去探索自然界神奇 的动物迁徙和变化。 赵渊源 动物的迁徙行为 动物行为学论文

目录 动物的迁徙行为 (2) 中文摘要 (2) 动物迁徙 (3) 动物迁徙的起源 (3) 动物迁徙中的惊人之举 (4) 动物迁徙的奥秘 (5) 动物迁徙的未解之谜 (6) 动物迁徙与人类的关系 (6) 动物大迁徙能否给人类一点启发 (7) 迁徙动物保护的几点建议 (8) 栖息地的保护 (8) 疾病的防治 (8) 人与动物和谐相处 (8) 【参考文献】 (9)

动物行为学论文—— 动物的迁徙行为 作者：赵渊源 学院：动物科学学院专业：2014级动物科学（实验动物）学号：85140413 中文摘要 动物迁徙是大自然界存在的一中普遍现象，引发的原因以及种类也有很多。动物的大规模的迁徙也给自然界的人类带来了许多的变化和反思，地球资源的枯竭和大气环境的日益变化，都给动物们带来了许多的威胁的危险，所以我们人类一定要时刻敲响着警钟，重视研究动物引起迁徙的原因，虽然还有太多的未解之谜，但是还是值得我们一起去探索自然界神奇的动物迁徙和变化。 关键词动物迁徙温度气候迁徙繁殖觅食 English Summary Animal migration is a widespread phenomenon exist in nature, there are many causes and types species triggered. Large-scale migration of animals but also to the nature of mankind brought many changes and reflection, changing the Earth's resources depletion and atmospheric environment, gave the animals brought many dangerous threat, so we humans must always He sounded the alarm, attention to the study of animal migration caused by the reasons, though there are too many mysteries, but still worthy of us to explore the nature amazing animal migrations and changes.

《候鸟的迁徙》阅读练习及答案

候鸟的迁徙 ①每年春天和秋天，人类会惊奇地仰望着天上那些成群结队、遮天蔽日而又神秘莫测的旅客 --候鸟。经过亿万年的自然进化，候鸟形成了每年在繁殖地与越冬地之间沿相对固定的路线 往返迁徙的独特习性。全世界9000多种鸟类中，超过三分之一的鸟都是候鸟，每年迁徙的 候鸟数量可达100亿只以上。 ②同一季节，随着纬度的改变，气温会产生梯度性的变化，特别是北半球的大块土地在冬季 被冰雪封盖，欧亚大陆和北美洲的许多鸟类不得不越过赤道，飞到南半球越冬。正因为这个原因，大多数候鸟的迁徙路线都呈南北方向，在北半球尤其明显。 ③人们用多种方法观测候鸟的飞行路线，如望远镜观察、雷达探测、给鸟涂颜料和环志等， 其中被世界各国普遍采用的是环志法。环志法是将金属或塑料做成脚环（或颈环、翅环），刻上环志国家、单位和编码，将环固定在候鸟的腿部（或其他部位），做好记录，将鸟放飞后，期望通过再次观测到它或回收脚环，这样能更好地了解被环志的鸟儿迁徙的时间、路线等数据。随着卫星应用技术的发展，科学家也在探索在大型候鸟身上安装小型无线电信号发 射器，通过定向接收机接收信号来观测候鸟的行踪。 ④经过长期监测，鸟类学家认为全世界候鸟迁徙路线主要有以下几条：东亚-澳大利亚、中亚-印度、西亚-东非、黑海-地中海、大西洋-美洲、密西西比-美洲和太平洋-美洲。这些迁徙路线就如一条条“高速公路”，任由鸟儿们飞来飞去，前往各自的目的地。 ⑤在迁徙的过程中，鸟类展示了非凡的智慧。硫磺鹀是美国东部随处可见的一种鸣禽，每年秋季，它们都会飞行3800千米，到达越冬地--墨西哥南部、巴拿马等地。让人惊奇的是， 它们是以星星为标记进行迁徙的。具体用来判断方位的是北极星中心约35°以内的北方天空，也就是说，在这个区域的大熊座、小熊座、天龙座、仙女座、仙后座等都是它们的路标，其卓越的导航本领让科学家惊叹不已。白颊林莺，从加拿大迁往南美洲时需要面对飞行路线 的选择：如果沿着美国海岸南下，经墨西哥、中美洲再到南美洲，就会减少死亡的可能，但 路途遥远。然而，这些小鸟的选择是直接勇敢的飞越大西洋，并有规律地停留在大西洋和加 勒比海的某些岛屿上休息。另外，白颊林莺还会选择好的天气和合适的风向，以使旅途更舒适，真是有勇有谋。 ⑥对候鸟来说，迁徙并不像人们想象的那样有乐趣。它们在迁徙途中要遇到许多想象不到的 困难：飞过大洋、翻越高山、穿越云层、迎着暴风雨、遭遇天敌，还有被人类捕食的危险…… 比如从英国出发的家燕，首先飞越英吉利海峡，穿过法国的比利牛斯山脉，跨过地中海，途经撒哈拉沙漠，再抗击热带风暴的袭击，抵达刚果的雨林，最后到达南非。经过超过10000

鸟类的迁徙行为

鸟类的迁徙行为 摘要：鸟类迁徙是自然界中十分常见的一种现象，鸟类迁徙是鸟类随着季节变化进行的，方向确定的，有规律的和长距离的迁居活动。在动物界中，类似的活动非常常见，在昆虫则称为“迁飞”，在鱼类则称为“洄游”，在哺乳动物则称为“迁移”。又是一年的冬季，鸟类又开始了它们的迁徙活动。 一、起源 鸟类为什么会按照一定路线准确无误地来回迁徙？虽然生物学家们已经作了大量研究，但却仍然未能揭开其中的奥秘。直到目前为止，鸟类学家所提出的所有解释都还是一些假说而已。 较多的人认为应该从从地球历史来考虑鸟类迁徙的起源问题，认为鸟类的迁徙习性起源于冰川时期。因为，在新生代第四纪曾发生过数次冰川运动，自北半球向南侵蚀，冰川来临，气候变冷，鸟类出于生存被迫南迁，等冰川退却时再北上。而冰川周期性的侵蚀和退却，使得鸟类形成了与之相适应的往返迁徙行为，于是便世代相传，形成习性。但此学说存在着一定的缺陷，它并不能解释为什么有的鸟类不迁徙，并且冰川期仅占鸟类生存历史的1％，如此短暂的时间，对鸟类遗传性的影响是有一定限度的；同时，也排除不了在冰川期以前鸟类即已开始迁徙的事实。 现在，大部分鸟类学者认为候鸟的迁徙是内在因素（如遗传性）和外在因素（光照、食物）所引起的综合性结果，内因是迁徙的根据，外因是迁徙的条件，外因通过内因而起作用二、途径 每种鸟类的迁徙路线不变，一般常沿食物丰富的近水地区迁移。以北美洲为例，鸟类的迁徙主要有四条迁徙的路径：(1)太平洋迁徙航路，美洲大陆西岸沿太平洋的路线。(2)密西西比航线，沿密西西比河迁徙。(3)中央迁徙航线，顺落矶山脉而行。(4)大西洋飞行航路，美洲大陆东岸滨临大西洋的沿线。而若以东亚为例，冬候鸟迁徙主要发生于秋、冬季节，其主要路径包括：陆路航线，自西伯利亚、中国大陆东北部、日、韩等地再经大陆沿海南迁至台湾、中南半岛或更南方的婆罗洲、甚或澳纽区域，如伯劳。若经由海线则经过阿留申群岛、日本诸岛、琉球、台湾等，再往南飞渡至菲律宾群岛、婆罗洲甚或远达澳、钮区域；春季时，候鸟则会返回北方繁殖地，如此每年循环一次。而东亚的夏候鸟则选择与冬候鸟相反的季节，每年由中南半岛经广东、福建沿海往北至台湾与其它区域避暑，如杜鹃。其它候鸟迁徙路线还有东非－西亚路线等。 许多鸟类有一种本能，即所谓“返巢本性”，这种本性反映出它们对于自己的出生地的眷恋，以及寻找旧居的能力。它能帮助鸟类在第二年繁殖季节，顺利地返回旧巢。有人曾捕获一只雕鴞，13年后，这只获得了自由的鸟儿竟回到了离故址不到2公里的地方。鸟类从千里之外定向识途的本领，一直是神奇的大自然的奥秘之一。它们靠什么来决定航向？它们的方向意识又是从何而来的？这始终是自然界中一个使人百思不得其解的谜。科学家通过环志、雷达、飞行跟踪和遥感技术等方法测到，鸟类在飞行时，往往主要依靠视觉，通过天空中日月星辰的位置来确定飞行方向。此外，地形、河流、雷暴、磁场、偏振光、紫外线等，都是鸟类飞越千里不迷航的依据。 一般认为，在白昼迁徙的鸟类是根据太阳来定位的，夜间迁徙的鸟类迁徙是根据星空定位。 三、影响因素 (一)气候和温度 在纬度较低的热带、亚热带地区候鸟较少而留鸟较多，而在中高纬度地区候鸟较多而留鸟较少。其主要原因是低纬度地区气候变化较小，常年温暖；而中高纬度地区冬季寒冷，气候变化较大。温度不仅仅影响了鸟类本身的感受同时也会影响鸟类的食物来源。 (二)日照的时间

鸟类迁徙的节律性

【鸟类迁徙的节律性】 鸟类迁徙行为具有明显的节律性。 （一）鸟类迁徙的生理节律 鸟类迁徙是一个漫长而有危险的旅程，长期自然历史的变迁形成了迁徙鸟每年呈现周期性的生理变化，神经调节和能量的存储均具节律性变动。 1、鸟类迁徙前的能量存储变动节律 鸟类迁徙期间的能量消耗完全依赖于体内以脂肪形式储存的能量，所以，鸟类在迁徙之前要积聚脂肪，以保证迁徙时的能量消耗。飞越沙漠和海洋的迁徙鸟类，由于途中无法获取食物，必须不停歇的一次完成整个迁徙，故而需要存储的脂肪更多。而其它大多数迁徙鸟类则可以中途降落到适宜的地点取食，并以很快的速度重新积聚已经耗损掉的脂肪，以便继续他们的旅程。 2、鸟类迁徙前的神经内分泌变动节律 鸟类迁徙所涉及的一系列活动是受神经内分泌系统控制的。随着日照的延长，通过松果腺的作用，由脑下垂体分泌两种激素，即皮质酮和催乳素。这两种激素的综合作用，使鸟类完成了一系列的生理准备，包括生殖腺发育、脂肪积累以及定向能力的增强等。 （二）鸟类迁徙的时间规律 1、鸟类迁徙的年节律 鸟类迁徙通常是一年两次，即春季由越冬地迁往营巢地，秋季由营巢地迁往越冬地。其迁徙日期因种而异，同时也受环境因子（营养等）的制约。迁到营巢地的日期与良好的生态条件来临的日期有关，每种鸟迁来和迁去的日期也有一定出入，一般来说，春季迁来营巢地较早的鸟，迁离的时间较早，迁来晚的鸟，迁离的时间也较晚。 2、鸟类迁徙的日节律 在鸟类迁徙的过程中，不同种鸟类不仅在年节律上有变化，在一日之间也有变化。一般有昼间迁徙和夜间迁徙以及昼夜迁徙等不同类型。各类型迁徙都有起始时间、高潮时间、结束时间的变化规律。食虫鸟类迁徙的时间大多是在夜晚，而大多数猛禽则是在白天进行迁徙。 （三）鸟类迁徙的性别、年龄节律 鸟类不仅不同种间有不同的迁徙节律，即使在同一种不同年龄或性别的鸟中相互也有不同。鸟类迁徙时，并非同一种鸟同时飞回或飞离出生地。首先是“先头部队”先飞，经过一段时间后，主群（基本群）开始迁飞，最后为迟到者（或掉队者）。这三群鸟的数量分配，随着种类和年份不同而有所差异，有的年份大部分鸟都紧跟着“先头部队”到来，有的则在其后很长时间到达。

肿瘤的几种转移途径

一肿瘤的转移途径： 1 淋巴道转移：（癌多见）。原发癌的细胞随淋巴引流，由近及远转移到各级淋巴结，也可能超级转移；或因癌阻碍顺行的淋巴引流而发生逆向转移。转移癌在淋巴结发展时，淋巴结肿大且变硬，起初尚可活动，癌侵越包膜后趋向固定，转移癌阻碍局部组 织淋巴引流，可能引起皮肤、皮下或肢体的淋巴水肿；如：乳腺癌同侧腋窝淋巴结；肺癌肺门、支气管旁淋巴结；鼻咽癌同侧颈淋巴结。 2 血道转移：癌细胞进入血管随血流转移至远隔部位如肺、肝、骨、脑等处，形成继 发性肿瘤；如：瘤细胞静脉肺和肝等（最多见），形成边缘整齐、散在、多发的球形结节，中央常发生坏死，近脏器表面形成“癌脐”。 3种植性转移：内脏器官的肿瘤，侵犯浆膜后，瘤细胞脱落入体腔，种植在浆膜面 上。如：肺癌胸膜腔；消化道癌或卵巢癌腹膜腔。 形态：浆膜增厚，表面癌结，血性积液，脱落细胞学检查可见癌细胞。 4.直接转移：随着肿瘤体积不断增大，肿瘤细胞可沿周围正常组织的薄弱处，直接延伸，侵入并破坏邻近组织或器官。如：直肠癌前列腺、膀胱、子宫及阴道壁等。 二此例的转移方式： 1.胃卵巢：种植性转移，胃癌浸透到脏器外表面时，随着呼吸或肠蠕动等相应的摩擦，可脱落到体腔继续生长 2.胃、肝、肺淋巴结：淋巴道转移，肿瘤细胞侵入淋巴管后，随淋巴液转移到淋巴结，在淋巴结内生长形成转移瘤，淋巴结肿大且变硬 3.胃肺、肝脏：血道转移，肿瘤细胞侵入血管后，随血流转移到全身各处称血道转移。侵入人体静脉系统的肿瘤细胞，先转移到肺，再经心脏扩散到全身各脏器。消化 道的恶性肿瘤常入侵门静脉系统转移到肝脏。 三 (1)阻塞和压迫：肿瘤的阻塞压迫发展迅速，程度也高，如肝肿大可以压迫神经；淋巴结肿大变硬，淋巴回流受阻。 (2)破坏所在器官的结构和功能：如肝癌由于肝细胞破坏和肝内胆管阻塞，可引起全身性黄疸。 (3)侵袭破坏邻近器官：如胃癌可穿胃壁，侵犯胃周围的器官。

第八章 细胞增殖和凋亡异常与疾病

第八章细胞增殖和细胞凋亡异常与疾病 一、A型题 1．细胞凋亡的概念是 A．由体内外因素引起的细胞渐进、缓慢的病变导致的细胞死亡过程 B．由体内外因素触发细胞内预存的死亡程序而导致的细胞死亡过程 C．由体内外因素诱导的一种生理性、主动的细胞死亡方式 D．由体内外因素引起的细胞急性、严重的改变导致的细胞死亡过程 E．由体内外因素诱导的一种病理性、被动的细胞死亡方式 [答案] B [题解] 细胞凋亡是指由体内外因素触发细胞内预存的死亡程序而导致的细胞死亡过程。 2．有关细胞凋亡的生理和病理意义下列哪一项是错误的？ A．确保机体正常发育D．保证机体正常生长 B．维持内环境稳定E．发挥积极的防御功能 C．促进生物进化 [答案] C [题解] 细胞凋亡的生理和病理意义包括：①确保机体正常发育、生长；②维持内环境稳定；③发挥积极的防御功能；并不包括促进生物进化。 3．有关细胞凋亡的特征下列哪一项是错误的？ A．由较弱刺激触发，可见于生理或病理情况 B．DNA片段化，电泳时呈“梯”状条带 C．溶酶体相对完整，局部无炎症反应 D．主动过程，耗能，无需新蛋白合成 E．胞膜皱缩内陷，分割胞浆成凋亡小体 [答案] D [题解] 细胞凋亡不仅是一个主动过程，需要耗能，而且还需要有新蛋白质合成。 5．促进细胞凋亡的基因是 A．Bcl-2 D．c-myc B．Fas E．Bcl-XL C．突变型p53 [答案] B [题解] Bcl-2、突变型p53和Bcl-XL都是抑制凋亡基因，而c-myc是双向调节基因，只有Fas基因是促进细胞凋亡的基因。 6．抑制细胞凋亡的基因是（0.377，0.392，03临床） A．Fas D．Bcl-2 B．野生型p53 E．Bcl-Xs C．c-myc [答案] D [题解] Fas、野生型p53和Bcl-Xs是抑制凋亡基因，而c-myc是双向调节基因，只有Bcl-2是抑制凋亡基因。 10．细胞凋亡时发生的变化下列哪一项出现最早？ A．线粒体膜通透性增加D．核酸内切酶激活 B．线粒体跨膜电位下降E．核转录因子激活 C．凋亡蛋白酶激活 [答案] B [题解] 线粒体跨膜电位下降使线粒体膜通透性增加，随后才引起凋亡蛋白酶激活、核酸内切酶激活以及核转录因子激活。 11．细胞凋亡的双向调节基因是 A．野生型p53 D．Bcl-2 B．Fas E．Bax C．c-myc [答案] C [题解] 野生型p53、F as和Bax是促进凋亡基因，Bcl-2是抑制凋亡基因，而c-myc才是细胞凋亡的双向调节基因。 13．细胞凋亡的主要执行者是 A．核转录因子和核酸内切酶D．凋亡蛋白酶和谷氨酰胺转移酶

鸟类的迁徙

鸟类的迁徙 鸟类的迁徙（migration of birds）是指鸟类中的某些种类，每年春季和秋季，有规律的、沿相对固定的路线、定时地在繁殖地区和越冬地区之间进行的长距离的往返移居的行为现象。这些具有迁徙行为的鸟种即为候鸟，或称迁徙鸟（migrator）。候鸟的迁徙具有一定的时期性、方向性、路线性和地域性。 研究鸟类的迁徙行为，了解候鸟的迁徙时间和路线、迁徙数量、种群关系、归巢能力、死亡率、存活率、寿命，以及与繁殖地、越冬地环境的关系等生态规律，对于保护珍稀濒危鸟种、利用候鸟保护农林生产和维护生态平衡、保障航空安全、计划利用经济候鸟、防止流行病的传播、制定法律等可以提供科学的依据，将会给人类带来巨大的社会和经济效益以及生态效益。 鸟类根据其迁移或迁徙的居留习性的分类 鸟类根据是否迁徙以及迁徙方式的不同，分为留鸟、候鸟、漂鸟和迷鸟等。 （一）留鸟(resident) 终年留居于其栖息区以内的鸟，统称为留鸟。留鸟一般终年栖息于同一地域，或者仅有沿着山坡的短距离迁移现象。 （二）候鸟(migrant) 指一年中随着季节的变化，定期的沿相对稳定的迁徙路线（migration route）, 在繁殖地和越冬地之间作远距离迁徙的鸟类。候鸟的迁徙通常为一年两次，一次在春季，一次在秋季。春季的迁徒，大都是从南向北，由越冬地区飞向繁殖地区。秋季的迁徙，大都是从北向南，由繁殖地区飞向越冬地区，但是几乎没有一种鸟是从它的繁殖地区笔直地飞往越冬地区的，而且中途还要多次在合适的驿站作停留。各种鸟类每年迁徙的时间是很少变动的。迁飞的途径也都是常年固定不变的，而且往往沿着一定的地势，如河流、海岸线或山脉等飞行。许多种鸟类，南迁和北徙，是经过同一条途径。各种鸟类迁徙的途径，是不相同的。雁类、鹤类等大型鸟类在迁飞的时候，常常集结成群，排成“一”字形或“人”字形的队伍；而家燕等体形较小的鸟类，则组成稀疏的鸟群；猛禽类的迁徙却常常是单独飞行，个体之间总是保持着一定的距离。绝大多数鸟类在夜间迁飞，以躲避天敌的袭击，特别是食虫鸟类，而猛禽大多在白天迁飞。 1：夏候鸟（summer resident）夏季在某一地区繁殖，秋季离开到南方较温暖地区过冬，翌春又返回这一地区繁殖的候鸟，就该地区而言，称为夏候鸟。 2：冬候鸟（winter resident）冬季在某一地区越冬，翌年春天飞往北方繁殖，到秋季又飞临这一地区越冬的鸟，就该地区而言，称为冬候鸟。 3：旅鸟（traveler 或migrant）候鸟迁徙时，途中经过某一地区，不在此地区繁殖或越冬，这些种类就称为该地区的旅鸟。 因此，同一种鸟在一个地区是夏候鸟，在另一个地区则可能是冬候鸟。

肿瘤侵袭和转移的恶性生物行为及分子干预

项目名称：肿瘤侵袭和转移的恶性生物行为及分子 干预 首席科学家：詹启敏中国医学科学院肿瘤医院肿瘤 研究所 起止年限：2009.1至2013.8 依托部门：教育部

一、研究内容1．细胞周期调控异常与肿瘤恶性增殖、侵袭相关分子机理 肿瘤是一种“细胞转导通路异常”性疾病,我们将通过分子生物学、细胞生物学、和动物模型相结合的研究技术，重点研究抑癌基因p53、BRCA1、Gadd45介导的信号通路与细胞周期蛋白Aurora-A、Cyclin B1、Plk1的相互作用，以及在细胞周期调控和肿瘤恶性表型形成中的生物学功能和分子机制。从而揭示细胞增殖失调与肿瘤侵袭转移的内在联系。 2．细胞凋亡和分化异常与肿瘤侵袭性生长的关系 细胞凋亡调控机制的异常与侵袭特性生长密切相关。促进细胞死亡的机制失活和抑制凋亡的分子的大量表达使癌症细胞存活延长，使基因突变的积累和癌变机会的增加，同时凋亡机制的异常导致肿瘤细胞具有抗药性。通过对细胞死亡新机制、肿瘤干细胞凋亡相关研究、细胞信号转导与凋亡调控等研究，深入探讨侵袭性生长的机制。 3．肿瘤干细胞和肿瘤微环境与肿瘤转移的内在关系 以恶性肿瘤干细胞特异性表型为突破口，从白血病干细胞延伸至实体瘤干细胞，研究其自我更新和分化的特性，探讨肿瘤转移的起始因素和关键分子生物学性质，认别恶性肿瘤干细胞与微环境或肿瘤“基质”间的相互作用机制,从而为特异性打击肿瘤干细胞作为彻底消除肿瘤转移潜能的一种新策略提供重要的理论基础。 4. 肿瘤血管和淋巴管新生介导的肿瘤转移机制 已鉴定肿瘤组织中血管表达Tim-3和淋巴管表达Sema4c等是沉默抗肿瘤免疫的重要活性分子，能通过与淋巴细胞的对话，诱导机体对肿瘤的免疫耐受，是

细胞凋亡与肿瘤

细胞凋亡与肿瘤 巴桑卓玛 (西藏大学医学院基础医学研究所) 摘　要　细胞凋亡是一种进化保守的细胞死亡形式,不仅在正常的生理状态具有重要作用,而且与多种疾病的发生发展密切相关。近年来研究认为,细胞凋亡异常可能与肿瘤发生有关。凋亡调控基因已被看作是一类新的肿瘤发生相关基因。肿瘤的发生,是由于细胞增殖与细胞凋亡之间的平衡失调的结果,细胞凋亡在肿瘤生长过程中起负调控作用,因此研究抑制多种肿瘤细胞增殖并诱导细胞凋亡而对正常细胞影响不大是肿瘤治疗的新思路。 关键词　细胞凋亡　诱导　治疗　肿瘤 多细胞机体,包括人,均存在着细胞增殖与死亡的平衡,以维持机体的稳态,二者是一个矛盾的两个方面,此矛盾的运动发展推动着机体的生、老、病、死。传统的肿瘤研究者关注的首先是细胞的增殖。肿瘤细胞是永生性细胞,如何抑制肿瘤细胞的无限增殖能力,是他们首先考虑的问题。然而,机体还存在另一普遍现象,即死亡。细胞的死亡有两种形式,一种是病理性死亡,称为坏死(necrosis)。它是由于局部缺血、高热、理化因素及微生物的侵袭所致的细胞急速死亡。其重要的特点是细胞肿胀、溶解、释放出裂解产物,使周围组织产生炎症反应。另一种是生理性死亡———凋亡(apoptosis)。 1　细胞凋亡与一般的死亡有很大的不同,主要表现以下几个方面 形态学特征:细胞凋亡是细胞在生物体发育过程中,在一定诱导条件下接受指令而发生的程序化事件,是导致最终自我消亡的生命活动。发生时首先是染色质的凝集,嗜碱性染色增强,然后细胞核崩解,此时线粒体保持形态正常,最后细胞体积缩小,一部分细胞质和核碎片进入由膜包被的程序死亡小体,它们从细胞表面出芽脱落,并被组织专职巨噬细胞、上皮细胞吞噬。由于细胞内容物不泄漏,因而没有炎症反应。 生化特征:染色质降解,核小体间连接DNA部位被降解,产生寡聚核小体DNA 片段,即180-200bp整数倍的不同长度的DNA片断。 细胞凋亡的化学信号:在细胞程序死亡时出现快速持续的Ca2+浓度上升。如在胞质钙离子载体tributyrin和抗-CD3抗体诱导的胸腺细胞凋亡中就发现有钙离子浓度升高的现象。研究发现Ca2+增加与A TP一起作用于染色质,使原来折叠的很紧的染色质变松散,露出亲水部分,以便脱氧核糖核酸酶(Dnase)水解。Danson (1993)发现Ca2+可以参与Ca-calmokulin dependent phospatase作用,产生凋亡。Wornonicz提出Ca2+可以直接作用于核内转录因子引起凋亡。另外Ca2+还可活化

鸟类迁徙的研究方法

鸟类迁徙的研究方法 鸟类的迁徙长期以来一直是人类最感兴趣的自然现象之一。早期研究鸟类迁徙的主要方法是通过观察来了解不同季节鸟类的种类、数量和迁徙规律。随着科技的不断进步．研究人员可以借助各种先进的仪器设备来研究鸟类的迁徙．鸟类迁徙的研究方法有了很大发展。这为深入了解鸟类的迁徙活动起到了重要作用。 鸟类迁徙是鸟类随着季节变化进行的，方向确定的，有规律的和长距离的迁居活动。在动物界中，类似的活动非常常见，在昆虫则称为“迁飞”，在鱼类则称为“洄游”在哺乳动物则称为“迁移”。迁徙是鸟类生命周期中风险最高的行为，受到体能、天敌等多种因素的制约，而人类的活动常常有意无意地破坏鸟类迁徙的补给站点，而给他们的迁徙制造更大的困难，有时甚至对某些物种的存续产生严重影响。2011年12月，美国千余候鸟迁徙，误将地面当海洋撞击身亡。 1.1野外观察 野外观察在海角、远离大陆的海岛以及山脉的隘口，在迁徙期常有大量的候鸟过境。通过观察，可以获得鸟类的种类、数量、迁徙时间和迁徙路线等大量基础资料。由于很多候鸟在夜间迁徙，需要采用圆月面观察法或云高计技术法借助月光或辅助光观察候鸟的迁徙飞行。如俄罗斯研究人员的多个曾在西至里海东至天山山脉横跨２２００ｋｍ地点利用圆月面观察法统计春季迁徙鸟类的数量，估算出约有７亿只候鸟在迁徙时飞过该区域。其中来自南亚地区的鸟类占８

５％，来自非洲地区的鸟类占１５％。然而对于很多候鸟而言。人们在地面观察到的鸟类可能只占迁徙鸟类的一小部分。 1.2雷达监测 雷达技术应用于鸟类迁徙的研究始于２０世纪５０年代。利用雷达监测鸟类的迁徙，可以不受天气条件和鸟类飞行高度对观察者的影响，获得鸟类迁徙飞行时的高度、方向和速度等大量信息。目前，先进的雷达设备可以监测到周围半径１００ｋｍ范围内飞行的鸟类，而对大型鸟类的监测半径可达５００ｋｍ。这样，通过多个雷达站的共同监测．可以了解在大的空间尺度上候鸟迁徙的信息。然而，利用雷达开展鸟类迁徙研究也有一些不足之处。大部分研究工作都是利用机场或气象站的雷达设备开展合作研究，因此研究地点的选择受到限制。雷达技术难以识别鸟类的种类，一般只能通过鸟类的个体大小、飞行速度、扇翅频率等信息来推测鸟类的类群。另外，雷达难以监测到贴近地面或海面飞行的鸟类。 1.3环志 环志是目前研究鸟类迁徙最常用、最普及的方法。在候鸟的繁殖地、越冬地或迁徙停歇地捕捉鸟类．将用金属或其他材料做成的带有编号的鸟环佩带在鸟体，然后将鸟在原地放飞以便在其他地点再次重新观察到或捕捉到，此种研究鸟类迁徙的方法称为鸟类环志。通过对比首次环志时和环志鸟类回收时所记录的信息，可以了解鸟类的迁徙路线、迁徙停歇地、迁徙范围、迁徙速度以及鸟类的寿命等信息。 首次鸟类环志是于１８９９年由丹麦教师Ｈ．Ｃ．Ｍａｒｔｅｎ

知识扩展：鸟类的迁徙之谜

鸟类的迁徙之谜 《吕氏春秋》中有“孟春之月鸿雁北，孟秋之月鸿雁来”之句，描述了鸿雁南北定期迁飞的现象，对鸟类迁徙特性进行了生动的概括。 对鸟类迁徙的研究是一个非常有趣的课题。鸟类一年之中在营巢地（出生地）与越冬地之间所进行的两次移居，称为鸟类的迁徙。具有迁徙特性的鸟被称为候鸟。那些营巢地和越冬地在同一地区的鸟类，称之为留鸟。对鸟类迁徙进行系统科学的研究始于18世纪，在伟大的自然科学家林奈的倡议下，建立了候鸟迁徙的观察网，首先对燕子、杜鹃、鹳类等进行了细致的观察记录。到了19世纪，有更多的科学家从事鸟类迁徙的研究，如著名的鸟类学家纳乌曼分了留鸟、漂泊鸟和候鸟，特别提出了天气、食物以及地理条件对迁徙的影响。19世纪末和20世纪初时，对迁徙的研究开始采用环志的方法。环志方法的应用为研究鸟类迁徙积累了许多宝贵的材料，为迁徙研究的系统性和科学性奠定了基础，并由此对鸟类的繁殖、越冬、迁徙时鸟类的先后次序、夜间迁徙或白昼迁徙、迁徙速度、主导方向、寿命、栖息地等方面进行了深入的研究。 关于鸟类迁徙的起因，有许多解释，目前被大家普遍接受的是“冰川说”。在第四纪冰川来临之前，地球上气候温和，鸟类是不进行迁徙的，而当冰川自北半球向南半球逐渐侵袭的时候，北半球气候变冷，出现冬季气候，不再适合鸟类生存，鸟类被迫向南迁飞，在南方较温暖的地方越冬；待冰川退却，即夏季来临，这些南迁的鸟类又返回原来的栖息地，即北方地区进行繁殖，这种冰川周期性的侵袭与退却，使鸟类定期往返于繁殖地和越冬地，久而久之，便形成了具有遗传性的迁徙行为。但是，“冰川说”对未受冰川侵袭的热带和亚热带鸟类的迁徙现象是无法解释的，因此，该学说仍有自身的局限性。有关迁徙的起因，仍然是有待于人们进一步探索的课题。 鸟类迁徙的定向机制同样是鸟类学家们非常感兴趣的问题。自本世纪50年代开始鸟类定向机制的研究以来，提出了许多理论假说。依据鸟接受的不同定向信息，分为视觉定向和非视觉定向。视觉定向是鸟对光刺激的一种反应，用于定向的光刺激有太阳、星辰、月球、陆标（陆地上的大型标志）及偏振光的偏振面。因此视觉定向有太阳定向、星辰定向、月球定向、陆标定向和偏振光定向。由于视觉定向不能在任何情况下提供鸟类定向所需的信息，常常受到日夜交替、气候

【9A文】肿瘤的转移机制综述

肿瘤转移的分子机制 陈露12级七临9班12170918 指导老师：马长艳 【摘要】恶性肿瘤是危害人类健康的全球公共卫生问题之一，为新世纪人类的第一杀手。转移是恶性肿瘤发生和演变过程中最危险的阶段，了解恶性肿瘤侵袭、转移发生机制，寻找相应阻断途径对遏制恶性肿瘤发展有重要作用。本文就恶性肿瘤细胞侵袭与转移机制的研究进展作一综述。 【关键词】恶性肿瘤、侵袭、转移机制 众所周知，转移是恶性肿瘤患者死亡的主要原因，大约90%的恶性肿瘤患者死于肿瘤转移[1]。肿瘤的转移过程包括从肿瘤的原发部位脱离，进入周围的基质，进入循环或淋巴系统，粘附在内皮细胞壁并向血管外迁移及在远处侵润，血管增生，形成新的转移灶等。从上个世纪StephenPaget提出肿瘤转移的种子-土壤学说到现在，人类对于肿瘤转移机制的研究已有一百多年历史。随着各种理论的不断完善，人们对于肿瘤转移这一极为复杂的病理过程有了更进一步的认识。肿瘤的转移主要与以下几个因素有关。 1.遗传异质性 实验证实，肿瘤细胞的同一转移性克隆中可以分离出不同恶性潜能的亚克隆，而高转移性克隆出现遗传学突变的频率要远远高于非转移性克隆，提示肿瘤转移是一个主动的过程，与基因组的不稳定性具有早期联系[2]。临床上与肿瘤转移相关的基因分为肿瘤转移促进基因及肿瘤转移抑制基因，如matal、H-ras、nm23、mts-1、WDNM、PGM21等，它们通过参与信号传导，诱导转移表型，调节细胞因子表达来诱导、促进、抑制肿瘤转移，如VaramballR等[3]研究发现EZH2在前列腺癌转移演进的过程中通过异位过表达和重建染色体等组成性抑制多种抑癌基因，并与肿瘤的转移和不良预后密切相关。肿瘤的遗传异质性是肿瘤细胞逃避免疫监视、产生化疗抗性、形成转移复发的根源，是抗转移治疗中不可忽视的重要环节。 2.上皮间充质转化EMT 2.1EMT概念 上皮间质转化(EMT)是指具有极性的上皮细胞转换成具有活动能力、能够在细胞基质间自由移动的间质细胞的过程，它以上皮细胞极性的丧失及间质特性的

抗肿瘤药物对细胞增殖及凋亡的影响

抗肿瘤药物对细胞增殖及凋亡的影响 【摘要】 本实验室自主创新实验。本实验主要有药物对细胞对细胞增长速率的影响，药物对细胞周期时相分布及细胞凋亡的影响和细胞凋亡的形态学观察等三个内容。通过本次实验我们了解了细胞生物学研究的基本思路和理解设计实验的基本原则的同时通过实际操作，理解了细胞增值与凋亡在有机体正常生命活动中的作用及意义，掌握细胞增值与凋亡分析的基本方法。 一、药物对细胞对细胞增长速率的影响 【实验原理】 1.细胞生长曲线：一般细胞传代之后，经过短暂的悬浮然后贴壁，随后度过潜伏期进入指数生长期。在细胞到达包和密度后，停止生长，进入平顶期，然后退化衰亡。典型的生长曲线可分为潜伏期，指数增长期，稳定期和衰退期。以存活细胞数对培养时间作图，及得生长曲线，生长曲线常用与测定药物等外来因素对细胞生长的影响。 2.利用MTT比色法测定药物等外来因素对细胞生长的影响： 黄色的MTT能被活细胞线粒体脱氢酶还原成不溶鱼水的蓝紫色产物——formazan,后者被溶解所呈现的色度反映出活生活细胞的代谢水瓶，死亡细胞则没有脱氢酶活性。Formazan产生的量与活细胞数成正比。 【实验步骤】 1.溶液的配制： ①MTT母液 ②裂解液 ③药物与对照组：A（对照），B，C，D 实验步骤： 2.细胞制备： 取对数生长期的细胞，用胰酶消化计数，配制悬液浓度为2.5~3×10 个/ml。

3.细胞的接种（96孔板）： 设定调零组，对照组，假药组（8个平衡孔），每孔加入200ul细胞悬液。 4.加药处理：细胞贴壁后，弃培养基，换等体积的药液。 5.对细胞生长情况进行测定： ①配制MTT使用液：无血清的5ml培养基中加入600ulMTT母液避光混匀。②待测细胞孔，弃去培养基，每孔加100ulMTT使用液。没有细胞的孔同样重复上述操作，作为调零孔，继续培养。 6.第二天，每孔加入100ul裂解液，调零孔中也加 7.下午取出孔板，用移液器充分混匀，每孔取出150ul样品，转移到检测板中。用考热的针头挑破孔中的气泡，用酶标仪读取OD值。 8.计算每种药物的生长抑制率（细胞生长抑制率=（1—药物组OD值/细胞对照组OD值）×100%） 二、药物对细胞周期时相分布及细胞凋亡的影响 【实验原理】 流式细胞仪(Flow Cytometer):是集激 光技术、电子物理技术、光电测量技术、计算机技术、细胞荧光化学技术以及单克隆抗体技术为一体的高科技细胞分析仪。流式细胞术(Flow Cytometry，FCM):利用流式细胞仪对处于快速直线流动状态中的细胞或亚细胞结构进行多参数、快速的定量分析和分选的技术。 2.PI荧光探针的特性： PI（碘化丙啶）为定量细胞化学的荧光染料，能插入双链DNA和RNA的碱基对之间，每隔5个碱基插入一个PI分子。如样品经RNA酶消化后，样品中的

《鸟的迁徙》

六年级综合实践 《鸟的迁徙》教学设计 一、主题内容分析： 本主题主要通过了对鸟的认识、鸟的分类、鸟迁徙的原因及感想。三个活动设计，每个活动主题分别安排了“问题与思考”“学习与探究”“实践与体验”“总结与交流”“拓展与创新”五个环节，遵循了循序渐进的原则，贴合小学生的心理特点和动手能力范围，活动中学生成功率高，把活动与能力、实践和生活紧密结合在一起，做到玩中学，学中玩的愉快学习目的。三个活动设计培养学生搜集、处理信息的能力，发现问题和解决问题的能力，以及互相合作和动手操作的能力。 二、主题教学目标 知识：了解候鸟迁徙过程中的自然常识。 情感：学习候鸟那种面对逆境不屈不挠的精神。 教学重点：了解鸟的种类及迁徙过程中的自然常识。 教学难点：学习候鸟那种面对逆境不屈不挠的精神。 三、教学策略分析： 有些鸟类人们可以常年都见到，而有些鸟类却像客人一样，每年在一定的季节来到人们身边，过一段时间就又飞走了。可以说，一年之中，任何一个地区鸟的种类都会随季节有些变化，每到一个季节，有些鸟飞来了，有些鸟飞走了。鸟类这种随着季节不同而变更生活地区的习性，称为迁徙。学习本课我主要运用①案例教学法：②合作探究法： 四、教学准备： 学生准备：1、课前利用各种途径查阅书籍或性上网查询，了解鸟类具有沿纬度季节迁移的特性 2、准备自己在自主学习中遇到的问题。 教师准备：1、按照课标要求搜集材料。 2、制作教学多媒体课件。 五、教学评价建议：

评价标准： 1.根据鸟类迁徙习性的有无，将鸟类分为留鸟和候鸟两大类。 等几个方面探究的内容要系统、准确。 2. 体验采取的方法、要正确。 评价方法建议： 1.注重评价的方式要有激励性、多元性和开放性。学生的每一个学习的过程，采取自我评价、小组评、教师评相结合的评价方法。 2.学生探究学习的过程中，教师要不断进行指导和鼓励，让学生感到学习的每一步都有成功的喜悦，同时还要关注学生个体差异，进行不同层次评价，让每一位同学都有成就感。 3.教师巡视个别指导评价，教师组织各组在班内互评，当场评价，对做分工合作较好的同学和小组，做到及时鼓励和表扬。 教学课时建议： 建议：两课时 六、教学过程 第一课时鸟的探秘 一、内容分析 本主题主要通过了对鸟的认识、鸟的分类、鸟迁徙的原因及感想。三个活动设计，每个活动主题分别安排了“问题与思考”“学习与探究”“实践与体验”“总结与交流”“拓展与创新”五个环节，遵循了循序渐进的原则，贴合小学生的心理特点和动手能力范围，活动中学生成功率高，把活动与能力、实践和生活紧密结合在一起，做到玩中学，学中玩的愉快学习目的。三个活动设计培养学生搜集、处理信息的能力，发现问题和解决问题的能力，以及互相合作和动手操作的能力。 二、学情分析 作为农村小学，对于五年级的学生来说，学生收集资料整理资料分析资料的能力不强，但在搜集和整理资料的过程中，同学们还是较积极主动的。 三、教学目标 知识：了解候鸟迁徙过程中的自然常识。

肿瘤细胞迁移实验(细胞划痕法)讲义

抗肿瘤药物5氟尿嘧啶对肿瘤细胞 迁移的影响 欧阳学文 （细胞划痕法） 实验导读 瘤组织的增殖失控、瘤细胞的分化异常、瘤细胞具有侵袭和转移的能力是恶性肿瘤最基本的生物学特征，而侵袭和转移又是恶性肿瘤威胁患者健康乃至生命的主要原因。因此研究肿瘤侵袭和转移的规律及其发生机制，对恶性肿瘤的防治有重要意义。 肿瘤转移是指恶性肿瘤细胞从原发部位侵入淋巴管、血管或体腔，至靶组织或靶器官，长出与原发瘤不相连续而组织学类型相同的肿瘤。前者称为原发瘤，后者称为转移瘤或继发瘤。 图1 肿瘤转移示意图 根据肿瘤异质性理论，大多数恶性肿瘤最初虽属单克隆起源，但它在不断增殖演进至临床明显的肿瘤时，由于瘤细

胞遗传性状的不稳定性(来自基因突变或缺失等)而不断地变异，造成该肿瘤内瘤细胞亚群表型的多样性，诸如瘤细胞的侵袭性、生长速率、转移能力，核型乃至对激素的反应性和抗肿瘤药物的敏感性等，这些瘤细胞亚群具有被此不同的特性即所谓异质性。异质性与肿瘤转移直接有关的就是癌细胞的转移潜能，癌细胞的转移潜能有高低之分，具有高转移潜能的筋细胞易发生转移。 肿瘤细胞的运动性，来源于细胞运动“接触抑制”的概念。通过体外培养正常和恶性结缔组织细胞，发现正常纤维母细胞在移动过程中引起的皱栖脑膜与其他细胞的表面接触时，往往产生细胞膜活动的抑制和移动中细胞的缩短，然后停止。当纤维母细胞生长过程中在培养皿上融合形成一单层时，细胞运动即显著受到抑制。间变的肉瘤细胞则缺乏接触抑制，瘤细胞的运动不会被正常纤维母细胞所抑制。 针对肿瘤转移这一复杂的过程，人们研制了各种抗转移药物，如血小板凝集抑制剂、血管生成抑制因子、内皮稳定因子、干扰素－α以及其他化学药物。

《鸟的迁徙》观后感

《鸟的迁徙》观后感 篇一：鸟的迁徙观后感 《鸟的迁徙》观后感 一直以来都很羡慕鸟儿，有一双飞翔的翅膀，可以自由自在地翱翔在无边际的蓝天，无忧无虑。我只是曾在自己的梦中尝试过这样的飞越过一段小小的助跑，轻轻舞动手臂，就可以俯瞰整个大地。 老师大力推荐这部《鸟的迁徙》的纪录片，令我也对它多了几份期待。纪录片里记录的大半是各种各样的鸟儿在空中翱翔的姿态，这是一件美好的事情，但是如果只有美好的事情就拍不出纪录片的那种真实性，也就很难令观众动容了。让我印象深刻的是，当我们所有人都沉浸在一群鸟儿成队形地排列在空中的美好姿态中时，突然一声突兀的枪声把我拉回现实，一只鸟坠下，几只鸟相继坠下，毫无征兆。导演是故意的吧，接下来是一群红鹅，在迁徙的路途中路过一座化工厂，它们很想在水中掸去旅途的灰尘，但是水已经被化工厂污染得不成样子，它们越过对它们来说已经是庞然大物的钢筋泥土，在粘稠的化学液体上，终于有一只红鹅被粘住，看着小伙伴都飞走，自己拼命扑腾翅膀，显然我们可以想象得到结局。亚马逊丛林有五颜六色的鹦鹉，在我的记忆里，鹦鹉比起鸟来，更像宠物，它们并不擅于飞翔，但是丛林里的鹦鹉似乎与其他的鸟类并没有什么不同，充满自然的野性。但是很快镜头就为我们展示了，被猎人捕捉到的鹦鹉，呆呆地望着本该属于自己的天空，现在却是一种奢侈。看到这里，我们心里是

什么滋味呢？人类到底在大自然里扮演的是什么样的角色呢？就当一个人都要对这个世界失望透顶的时候，总会发生一些事情让人格外感动，心里一下子释怀。当那个老妪从屋子里拿出那一把粮谷时，鸟儿一点点接近，最终信任了面前的人类。好像世界一下子又变得美好起来。看到这里，我好像可以领会到老师所说的，好的自然类纪录片最终是回归到人性上的。鸟的迁徙，就像一个人的人生旅途，一生朝着自己的人生追求，会有中途站，会累，会有志同道合的伙伴，会需要休息，会有突发情况，会遇到各种各样的危险，各种各样的考验，但是要一直相信美好的事情会发生，总会有愿意帮助自己的人。迁徙的鸟成千上万，有追求的人也是成千上网，能够真正完成迁徙的鸟却是很少，能够真正完成追求的人也是很少，不同的是，鸟的迁徙始终没有放弃，迁徙对它们来讲与其说是生存的需要，不如说更像一种使命。但是人不同，人太容易受到外界的影响了，时而盘旋，时而止步不前，很多时候人无法走到最后，是因为无法战胜内心的自己，坚持成了一种难得的品质，我想这也是我们需要从这些令人敬佩的鸟儿身上反思自己的吧！ 看完这部纪录片，我想我也可以有自己的蓝天，即使没有翅膀，因为远方，更重要的在乎于心灵的飞翔。 篇二：迁徙的鸟观后感 《迁徙的鸟》观后感 当我们听到天空上大雁的高亢鸣叫，抬头看到蓝天上它们排着人

肿瘤细胞凋亡的关系

第10卷　第1期中　华　男　科　学 Vol.10　No.1 2004年1月 National Journal of Andrology Jan.2004 ?论著? survivin 蛋白在前列腺癌中的表达及其与 肿瘤细胞凋亡的关系 高吴阳1,胡传义1,易慕华2 (三峡大学仁和医院,1.泌尿外科,2.病理科,湖北宜昌443001) 摘要:　目的:探讨新的凋亡基因survivin 蛋白在前列腺癌(PCa )的表达及其与肿瘤细胞凋亡的关系。　方法:采用免疫组化SP 法和DNA 原位未端标记T UNE L 法分别测定42例PCa 组织及10正常前列腺(NP )组织中survivin 蛋白的表达和细胞凋亡。　结果:survivin 蛋白在PCa 中的阳性表达为80.59%,与病理分级、临床分期和淋巴结转移密切相关(P <0.05),而NP 中无阳性表达;PCa 组织及NP 组织中细胞凋亡指数(AI )分别为3.03±1.33、1.07±0.77,其差异有显著意义(P <0.05);survivin 蛋白的表达与细胞AI 呈负相关(r =-0.679,P <0.001)。　结论:survivin 蛋白的异常表达而引起的细胞凋亡抑制,在PCa 的发生、发展中起一定的作用;联合检测survivin 蛋白和AI ,有助于对肿瘤细胞的分化程度作出正确评价,以指导临床治疗及估计预后。关键词:survivin 蛋白;凋亡;前列腺癌;免疫组化 中图分类号:Q255;R737.25 文献标识码:A 文章编号:100923591(2004)0120012203 Expression of survivin Protein in Prostatic Carcinoma Tissues and Its Correlation with Apoptosis of Cancer Cells G ao Wuyang ,Hu Chuanyi ,Y i Muhua Department o f Urology (Gao WY ,Hu CY ),Department o f Pathology (Yi MH ),Rehe Hospital ,Three Gorges Univer sity ,Yichang ,Hubei 430031,China Correspondence to :Gao Wuyang Abstract :　Objective :T o investigate the expression of survivin protein in the tissues of prostatic carcinoma and its correlation with apoptosis of cancer cells.　Methods :Expression of survivin protein and apoptosis index (AI )were detected by immunohistochemical and terminal de 2oxynucleotidyl transterase 2mediated dUTP biotin nich end labeling (T UNE L )technique in the tissues of 42cases of prostatic carcinima (PCa )and 10cases of normal prostate (NP ).　Results :Survivin prosteins were expressed in 34of the 42(80.59%)cases of PCa.The positive rate of survivin was strongly ass ociated with pathological grades ,clinical stages and lymphmetastasis in PCa (P <0.05).In contrast ,NP did not express survivin.Survivin protein expressioin was negatively correlated with AI in PCa (r =-0.679,P <0.001).　Conclusions :Apop 2tosis inhibition by survivin may participate in the onset and progression of PCa ,and the detection of survivin protein and AI in PCa may help to evaluate the degree of cell diferentiation ,decide therapeutic strategies and estimate prognosis.　Natl J Androl ,2004,10(1):12214K ey w ords :survivin protein ;apoptosis ;prostatic carcinoma ;immunohistochemistry 前列腺癌(prostatic carcinoma ,PCa )是男性泌尿生殖系肿瘤中最重要的一种,其病因和发病机制尚 ?21?收稿日期:2003207215;修回日期:2003210208 作者简介:高吴阳(19622),男,湖北宜昌市人,副主任医师,本科,从事泌尿男科学专业。通讯作者:高吴阳