非小细胞肺癌中PAX6表达及其对肿瘤细胞增殖与侵袭作用机制研究

背景与目的：转录因子PAX6主要表达于胚胎期,不同肿瘤中PAX6呈现高表达,通过不同的信号通路发挥肿瘤抑制或促进作用。检测PAX6在非小细胞肺癌(non-small cell lung cancer,NSCLC)中的表达,通过RNAi下调其表达,研究PAX6对肿瘤细胞侵袭和增殖力以及cyclin E、p38表达水平的影响。方法：应用蛋白印记检测86例NSCLC肿瘤组织及癌旁配对组织以及2例细胞系中PAX6的表达情况。应用PAX6特异性siRNA序列,转染NSCLC细胞系A549,MTT法、Transwell小室、划痕实验检测转染前后细胞增殖、侵袭和迁移能力的对比。蛋白质印记法(Western blot)检测转染前后cyclin E及p38表达情况。结果：对比癌旁组织及正常人支气管上皮细胞16HBE,PAX6在NSCLC组织及A549细胞系中显著高表达。选取高效siRNA序列转染细胞系后,PAX6表达的下调抑制了肿瘤细胞的增殖及集落形成,G1期细胞比例增加,细胞侵袭及迁移力均下降。PAX6基因敲低细胞cyclin E及p38活性受到抑制,表达下调。结论：PAX6通过调控MAPK通路及cyclin E的表达加速肿瘤细胞的增殖、侵袭及迁移,是潜在的NSCLC诊疗靶点。     

细胞周期蛋白激酶抑制蛋白p27kip1在肿瘤预后中的研究现状

细胞增殖是可调控的，细胞周期正向和负向调节因素参与其中。目前已发现细胞周期蛋白／周期蛋白激酶抑制剂同细胞周期Ｇ１期的调控有关。这此抑制剂中，ｐ２７＾ｋｉｐ１的研究特别受重视，在Ｇ１期细胞周期蛋白／周期蛋白激酶复合物的调节中起主要作用。ｐ２７高表达可引起Ｇ１期阻滞，抑制多种癌细胞的生长。目前仅在少数种类的肿瘤中检测了ｐ２７的免疫活性。在结肠癌和乳腺癌中，ｐ２７低表达与肿瘤进展和低生存率相关。研究证明     

Insufficient effect of p27(KIP1) to inhibit cyclin D1 in human esophageal cancer in vitro

The cell cycle is controlled by protein complexes composed of cyclins and cyclin-dependent kinases. p27KIP1 (p27) is one of the Kip/Cip family cyclin-dependent kinase inhibitory proteins which negatively regulate cell cycle progression, and have been proposed as candidate tumor suppressor genes. To examine the role of p27 in the development of human esophageal squamous cell carcinoma (ESCC), we performed Western blot and immunoprecipitation analyses of the levels of expression of p27 protein in a series of ESCC cell lines. This protein was expressed at various levels in these cell lines during exponential growth. p27 level was significantly associated with that of cyclin D1, but not of cyclin E. Further cell cycle synchronization studies demonstrated that p27 was free or bound with affinity to cyclin E-CDK2 more than to cyclin D1-CDK4 or cyclin D1-CDK6. It is known that overexpression of cyclin D1 rather than cyclin E is involved in the pathogenesis of ESCC. Our findings indicated that high expression of p27 throughout the G1 to S phase may inhibit more likely cyclin E, than cyclin D1, which promotes tumor growth of esophageal squamous cell carcinoma.     

Ovarian cancer cells that coexpress endogenous Rb and p16 are insensitive to overexpression of functional p16 protein

Defects of the 'Rb/cyclin D1/p16 pathway' have been shown to play a critical role in the development of virtually all human malignancies assessed. To determine the contribution of G1 phase cell cycle defects to ovarian tumorigenesis, we have examined a panel of normal and tumor ovarian tissues and ovarian cancer cell lines for the expression of Rb, p16 and cyclin D1 proteins. Unlike most types of human cancer whose development involves the loss of either Rb or p16 expression, we observed the coexpression of Rb, p16 and cyclin D1 in 82% of ovarian cancer tissues and cell lines. Furthermore, the growth and cell cycle distribution profiles of three ovarian cancer cell lines (ES-2, PA-1 and NIH OVCAR-3) that coexpressed Rb and p16, were found to be unaffected by adenoviral-mediated overexpression of functional p16 protein, indicating the existence of a defect(s) downstream from p16 in these cells. By contrast overexpression of ectopic p16 in the one ovarian cancer cell line (SK-OV-3) that expressed Rb but lacked p16 protein, resulted in a G1 growth arrest. These data suggest that defects of the 'Rb/cyclin D1/p16 pathway', other than the loss of Rb or p16, may play a major role in the development of ovarian cancer.     

Cyclin D1 expression in papillary superficial bladder cancer: its association with other cell cycle-associated proteins, cell proliferation and clinical outcome.

Cyclin D1 contributes to regulate G1 progression by forming a complex with different cyclin-dependent kinases. It has oncogenic properties and is frequently overexpressed in several human tumor types. In our study, expression of cyclin D1 and Ki67, a proliferation marker, was evaluated by immunohistochemistry in human papillary superficial (pTa-pT1) bladder cancers and was correlated with p27(Kip1), p21(Waf1) and c-erbB-2 expression, with p53 gene status and protein expression, ploidy and cancer progression. Cyclin D1 expression was neither associated with tumor stage nor with tumor grade but high cyclin D1 expression (> or =25% positive nuclei) was significantly associated with p53 gene mutation (p = 0.012), low p21(Waf1) (p = 0.015) and high p27(Kip1) (p = 0.016) protein expression. Ki67 expression was not associated with tumor stage but a high proliferation index (> or =10% positive nuclei) was significantly associated with high tumor grade (p = 0.001) and with DNA aneuploidy (p = 0.005). There was no significant difference in proliferative activity between high and low cyclin D1 expressor tumors. Patients whose tumors showed high expression of cyclin D1 displayed a significantly longer disease-free survival (p < 0.001 by log-rank test). Increased Ki67 expression was significantly associated with shorter disease-free survival (p = 0.003). Both cyclin D1 (p = 0.027; RR = 1.898) and Ki67 (p = 0.047; RR = 1.932) protein expressions were independent predictors of reduced disease-free survival on a multivariate analysis that also included p27(Kip1) expression and tumor stage. The simultaneous presence of low cyclin D1, low p27(Kip1) and high Ki67 expression defined a "high-risk" group of patients who displayed a significantly increased risk of recurrence (p < 0.0001). These results suggest that evaluation of cell cycle-associated markers can help to identify high-risk patients and may affect the management of patients with papillary superficial bladder cancer.     

Role for dipeptidyl peptidase IV in tumor suppression of human non small cell lung carcinoma cells

Lung cancer is the leading cause of cancer death. Lung cancers produce a variety of mitogenic growth factors that stimulate tumor cell proliferation and migration. The cell surface protease, dipeptidyl peptidase IV (DPPIV), is involved in diverse biologic functions, including peptide-mediated cellular growth and differentiation. DPPIV is expressed in various normal tissues, including lung tissue, and its expression is lost in many types of human cancers. DPPIV expression and its enzymatic activity are detected in normal bronchial and alveolar epithelium but different histologic subtypes of lung carcinomas lose DPPIV expression. To investigate the role of DPPIV in lung carcinoma, we examined the expression of DPPIV at both mRNA and protein levels in non small cell lung cancer (NSCLC) cell lines and normal human bronchial epithelial cells. DPPIV expression was detectable in normal lung epithelial cells, but was absent or markedly reduced in all NSCLC cell lines at both mRNA and protein levels. Restoration of DPPIV expression in NSCLC cells resulted in profound morphologic changes, inhibition of cell proliferation, anchorage-independent growth, in vitro cell migration and tumorigenicity in nude mice. DPPIV reexpression also correlated with increased p21 expression, leading to induction of apoptosis and cell cycle arrest in G1 stage. These effects were accompanied by increased expression of cell surface proteins, fibroblast-activating protein (Fapalpha) and CD44 that are associated with suppression of tumor growth and metastasis. Thus, DPPIV functions as a tumor suppressor, and its downregulation may contribute to the loss of growth control in NSCLC cells.     

Galectin-3 and cyclin D1 expression in non-small cell lung cancer

Introduction

Lung cancer is a major cause of mortality and morbidity worldwide. Galectin-3 is multifunctional protein, which is involved in regulation of cell growth, cell adhesion, cell proliferation, angiogenesis and apoptosis. Cyclin D1 together with other cyclin plays an important role in cell cycle control. Cyclin D1 regulates the G1-to-S phase transition. The aim of this study was the evaluation of correlations between clinicopathological findings and cyclin D1 and galectin-3 expression in non-small cell lung cancer (NSCLC). We wanted also to analyze the prognostic value of cyclin D1 and galectin-3 expression. Moreover we tried to evaluate the correlations between galectin-3 and cyclin D1 expression in tumor tissue.

Materials and methods

We used the immunochemistry method to investigate the expression of galectin-3 and cyclin D1 in the paraffin-embedded tumor tissue of 47 patients (32 men and 15 women; mean age 59.34 ± 8.90). years. We used monoclonal antibodies to cyclin D1 (NCL-L-cyclin D1-GM clone P2D11F11 NOVO CASTRA) and to galectin-3 (mouse monoclonal antibody NCL-GAL3 NOVO CASTRA).

Results

Galectin-3 expression was positive in 18 cases (38.29%) and cyclin D1 in 39 (82.97%). We showed only weak trend, that galectin-3 expression was lower in patients without lymph node involvement (p = 0.07) and cyclin D1 expression was higher in this group (p = 0.080). We didn''t reveal differences in cyclin D1 and galectin-3 expression in SCC and adenocarcinoma patients. We didn''t demonstrated also differences in galectin-3 and cyclin D1 expression depending on disease stage. Moreover we analyzed the prognostic value of cyclin D1 expression and galectin-3 in all examinated patients and separately in SCC and in adenocarcinoma and in all stages, but we didn''t find any statistical differences. We demonstrated that in galectin-3 positive tumors cyclin D1 expression was higher (96.55% vs 61.11%, Chi² Yatesa 7.53, p = 0.0061) and we revealed negative correlation between cyclin D1 and galectin-3 expression (R Spearman -0.458, p = 0.0011). In squamous cell lung cancer we didn''t observed correlations between these both examinated markers (R = -0.158, p = 0.460), and in adenocarcinoma the negative correlation was very strong (R = -0.829 p = 0.000132).

Conclusions

We didn''t reveal any important correlations between clinicopathological findings and galectin-3 and cyclin D1 expression and in non small cell lung cancer. We didn''t observed also prognostic value of cyclin D1 or galectin-3 expression. But we showed higher cyclin D1 expression in galectin-3 negative tumor tissues. We revealed also differences in correlations between galectin-3 and cyclin D1 expression in two main histopathological types of NSCLC.     

Prognostic significance of p21waf1, cyclin D1 and retinoblastoma expression detected by immunohistochemistry in non-small cell lung cancer.

p21waf1 is a downstream effector of p53, and mediates growth arrest by inhibiting the action of G1 cyclin-dependent kinases. Cyclin D1 is a cell-cycle regulator essential for G1 phases progression and a candidate proto-oncogene implicated in the pathogenesis of several human tumor types. Cyclin D1 overexpression and the absence of retinoblastoma (Rb) protein have been frequently seen in various types of cancer, including lung cancer. The aim of this study was to clarify the relationship between the expressions of p21waf1, cyclin D1, and Rb protein, and to investigate the correlation between these protein expressions and the clinical features of the patients, and their prognoses. We immunohistochemically examined 92 samples of resected non-small cell lung cancer for p21waf1, cyclin D1, and Rb expression. Of the 92 specimens examined, 43 cases (46.7%) showed p21waf1 expression, 23 cases (25.0%) showed cyclin D1 overexpression, and 61 cases (66.3%) showed Rb expression. No correlation was observed between the expressions of p21waf1, cyclin D1, and Rb. There was no association of p21waf1 and cyclin D1 immunoreactivity with gender, disease stage, or histological types of the tumor. Regarding the prognosis in 79 cases with complete resection, no statistical differences were observed according to the degree of expression of these three factors. However, when unfavorable prognostic factors were considered to be the positive expression of p21waf1, positive of cyclin D1, and negative of Rb, the 5-year disease-free survival rate in the group with 2 or 3 unfavorable prognostic factors was 21.1%, which was statistically poorer than the 45.4% in the group with 0 or 1 unfavorable prognostic factor (p=0.0138). We conclude that examination of the expression of cell cycle regulators, such as p21waf1, cyclin D1, and Rb, is useful as a prognostic indicator, when these proteins' expression is analyzed in combination.     

p53、Cyclin D1及PCNA在非小细胞肺癌的表达

目的 研究非小细胞肺癌（NSCLC）中p53、Cyclin D1蛋白表达及与细胞增殖的关系。方法 应用免疫组织化学技术（SP法）检测74例NSCLC中p53、Cyclin D1蛋白和增殖细胞抗原（PCNA）的表达情况。结果 p53蛋白、CyclinD1蛋白在NSCLC中阳性表达率分别为55．41％和37．84％,均明显高于正常肺组织（P1＝0．0031,P2＝0．0429）。 p53蛋白表达与淋巴结转移有密切关系（P＝0．0222）。p53蛋白、CyclinD1蛋白表达分别与PCNA指数有密切关系（P1＝0．001,P2＝0．0009）。p53蛋白与CyclinD1蛋白表达之间未见明显关系（P＞0．05）。结论 p53蛋白和CyclinD1蛋白近表达参与了NSCLC的发生发展,有促进细胞增殖的作用。p53的诊断和评价NSCLC预后的重要参数。     

Cell cycle arrest and inhibition of anoikis by galectin-3 in human breast epithelial cells.

Galectin-3 is a member of a growing family of animal beta-galactoside-binding proteins shown to be involved in cell growth, differentiation, apoptosis resistance, and tumor progression. In the present study, we investigated whether galectin-3 can protect against apoptosis induced by the loss of cell anchorage (anoikis). Because studies suggest that cellular sensitivity to anoikis is associated with cell cycle regulation, we examined the role of galectin-3 on cell cycle regulation. Although BT549 cells (human breast epithelial cells) undergo anoikis, galectin-3-overexpressing BT549 cells respond to the loss of cell adhesion by inducing G1 arrest without detectable cell death. Galectin-3-mediated G1 arrest involves down-regulation of G1-S cyclin levels (cyclin E and cyclin A) and up-regulation of their inhibitory protein levels (p21(WAF1/CIP1) and p27KIP1). After the loss of cell anchorage, Rb protein becomes hypophosphorylated in galectin-3-overexpressing cells, as predicted from the flow cytometric analysis and immunoblot analysis of cyclins and their inhibitors. Interestingly, galectin-3 induces cyclin D1 expression (an early G1 cyclin) and its associated kinase activity in the absence of cell anchorage. On the basis of these results, we propose that galectin-3 inhibition of anoikis involves cell cycle arrest at an anoikis-insensitive point (late G1) through modulation of gene expression and activities of cell cycle regulators. The present study suggests that galectin-3 may be a critical determinant for anchorage-independent cell survival of disseminating cancer cells in the circulation during metastasis.     

Adenovirus expressing p27(Kip1) induces growth arrest of lung cancer cell lines and suppresses the growth of established lung cancer xenografts

p27(Kip1) (p27) is a member of the universal cyclin-dependent kinase inhibitor (CDKI) family and a putative tumor suppressor gene. In several tumors including lung cancer, decreased expression of p27 is associated with poor prognosis. These observations suggest a potential role for p27 as a new gene therapy target. In this study, we constructed adenovirus expressing human p27 (ad-p27) and investigated its antitumor effects on human lung cancer cell lines. Upon transduction of several human lung cancer cells with ad-p27, a high level of p27 expression, with a decrease in cdk2 and an increase in cyclin E were observed. These changes resulted in G1/S arrest. Transduction of human lung cancer cell lines with ad-p27 showed in vitro growth inhibition and a marked suppression of colony formation upon soft agar clonogenic assay. Direct intratumoral injection of ad-p27 induced the growth suppression of established lung tumors in nude mice. From these observations, gene therapy using ad-p27 seems to offer a potential basis for the development of new cancer gene therapy modality and a useful tool to investigate the mechanisms of cell cycle control.     

非小细胞肺癌组织中PTEN/p27kip1的表达及其意义

目的检测PTEN、p27kip1、cyclin 3种蛋白在非小细胞肺癌组织的表达及与临床病理特征的关系.方法在60例非小细胞肺癌原发灶(包括37例鳞癌和23例腺癌)中应用免疫组织化学S-P法检测3种蛋白的表达.结果 60例肺癌原发灶中PTEN、p27kip1、cyclin 3种蛋白表达阳性率分别为:48.3%;41.7%;73.3%.PTEN与淋巴结转移显著相关(<0.05)p27kip1、cyclin 与淋巴结转移无关(>0.05)这3种蛋白表达均与肿瘤细胞分化程度显著相关(<0.05)与组织学类型无关(>0.05)60例非小细胞肺癌组织中,PTEN的表达与p27kip1呈显著正相关(P<0.01),而与cyclin 无明显相关(>0.05)p27kip1与cyclin 的表达之间呈显著负相关(P<0.01).结论 PTEN明显地抑制了非小细胞肺癌的浸润和转移,p27kip1表达缺失与肺癌细胞的分化有关,PTEN/p27kip1衰老诱导途径在非小细胞肺癌的恶性进展中起着很重要的作用.     

FHL2 exhibits anti-proliferative and anti-apoptotic activities in liver cancer cells

FHL2 displays tumor promoting or tumor suppressing activities depending on the types of tumor cells. In this study, we demonstrated that FHL2 overexpression inhibits the proliferation of human HCC cells Hep3B through cell cycle regulation by decreasing cyclin D1 expression while increasing the expressions of p21 and p27. FHL2 overexpression also inhibits migration and invasion of Hep3B cells through the regulation of epithelial-mesenchymal transition. Surprisingly, we also demonstrated an antiapoptotic function for FHL2 overexpression with increased resistance to doxorubicin-induced apoptosis, which indicates the separation of anti-proliferative and anti-apoptotic role of FHL2. Taken together, our results indicate FHL2 could exert anti-apoptotic effect independent of tumor growth suppression.     

细胞周期蛋白D2和p27^kipl在非小细胞肺癌中的表达及意义

目的探讨细胞周期蛋白D2(cyclin D2)和p27kipl在非小细胞肺癌(NSCLC)中的表达及意义.方法采用免疫组化S-P法检测63例非小细胞肺癌(NSCLC)组织中cyclin D2和p27kipl的表达情况.结果 63例NSCLC中cyclin D2和p27kipl阳性表达率分别为39.7%和54.0%,与正常支气管黏膜比较差异有显著性(P<0.05).p27kipl的表达与NSCLC的分化程度、淋巴结转移以及临床病理分期相关(P<0.05).cyclin D2与p27kipl的表达呈显著负相关.结论 cyclin D2和p27kipl的异常表达与NSCLC的发生有密切关系.p27kipl还与NSCLC的进展有关,并可作为估计预后的重要指标.     

Modulation of cell cycle regulatory protein expression and suppression of tumor growth by mimosine in nude mice

Our previous results demonstrated that the plant amino acid mimosine blocked cell cycle progression and suppressed proliferation of human lung cancer cells in vitro by multiple mechanisms. Inhibition of cyclin D1 expression or induction of cyclin-dependent kinase inhibitor p21WAF1 expression was found in mimosine-treated lung cancer cells. However, whether mimosine may modulate the expression of these cell cycle regulatory proteins and suppress tumor growth in vivo is unknown. In this study, we examined the anti-cancer effect of mimosine on human H226 lung cancer cells grown in nude mice. Our results demonstrated that mimosine inhibits cyclin D1 and induces p21WAF1 expression in vivo. Furthermore, results of TUNEL analysis indicated that mimosine may induce apoptosis to suppress tumor growth in nude mice. Collectively, these results suggest that mimosine exerts anti-cancer effect in vivo and might be useful in the therapy of lung cancer.