Cyclin D1 expression in transitional cell carcinoma of the bladder: correlation with p53, waf1, pRb and Ki67

Normal cell proliferation is closely regulated by proteins called cyclins. One of these, cyclin D1, in combination with its corresponding cyclin-dependent kinase (cdk), is essential for G(1)/S phase transition. Cyclin/cdk complexes are generally inhibited by cyclin-dependent kinase inhibitors(ckis), some of which are induced by wild-type p53. The aims of this study were: to investigate levels of cyclin D1 expression in transitional cell carcinoma (TCC) of the bladder; to correlate these results with data concerning the expression of p53, waf1, pRb and Ki67; and to determine whether cyclin D1 expression could predict clinical outcome. Paraffin-sections from 150 newly diagnosed bladder tumours (Ta/T1 = 97; T2-T4 = 53) were stained for cyclin D1 using immunohistochemistry and a cyclin D1 index assigned. These results were correlated with data relating to the expression of p53 and waf1 by the same tumours. A representative subset of 54 tumours (Ta/T1 = 28; T2-T4 = 26) was also stained for Ki67 and 55 were stained for pRb. The clinical course of each patient was recorded and multivariate analyses of risk factors for tumour recurrence, stage progression and overall survival were performed. Positive staining for cyclin D1 was found in 83% of tumours. The staining pattern varied between tumours with nuclear, cytoplasmic or a combination of the two evident in different tumours. 89% of Ta/T1 and 74% of T2-T4 tumours showed nuclear staining with or without cytoplasmic staining. The median value for cyclin D1 staining was significantly higher in Ta/T1 tumours (41%) compared with T2-T4 tumours (8%, P< 0.005) with 26% of muscle-invasive tumours demonstrating absent staining. In addition, the median value for cyclin D1 staining was significantly higher in G1/G2 tumours (43%) compared with G3 tumours (14%, P< 0.005). There was a significant positive correlation between expression of cyclin D1 and waf1 expression (P< 0.0001) as well as pRb expression but not between cyclin D1 expression and expression of p53. Ki67 expression was significantly associated with increasing tumour stage (P< 0.005) and histological grade (P< 0.05) but did not correlate with cyclin D1 expression. A cyclin D1 index > or = 8% was associated with significantly better survival in those patients with muscle-invasive disease (T2-T4). In addition, there was a significantly higher progression rate for those patients with Ta/T1 disease whose tumours demonstrated cytoplasmic cyclin D1 staining. These results indicate that cyclin D1 expression is significantly higher in low-stage, well differentiated bladder tumours and strongly correlates with waf1 expression. In a multivariate analysis, cyclin D1 expression is an independent prognostic indicator of survival in those patients with muscle-invasive disease.     

Decreasing of p27(Kip1)and cyclin E protein levels is associated with progression from superficial into invasive bladder cancer

The p27(Kip1)(p27) protein is a cyclin-dependent kinase inhibitor of the transition from G1 to S phase. It has been reported that decreased p27 protein level is a negative prognostic indicator in human tumours including bladder cancer. We studied the relationship between protein levels of p27, cyclin E and Ki-67 and clinicopathological features of 145 consecutive Japanese patients with transitional cell carcinoma of the bladder using immunohistochemical staining. Low protein levels of p27 were associated with low staining of cyclin E (P = 0.0302), high Ki-67 index (P = 0.0306), poorly differentiated grade (P = 0.0006), muscle invasion (P = 0.0019) and lymph node metastsis (P = 0.0002). Low staining of cyclin E and high Ki-67 index correlated with poorly differentiated grade, muscle invasion and lymph node metastsis. Cyclin E protein levels was inversely related with Ki-67 index (P = 0.0002). Kaplan-Meier plots of survival rate in patients with low versus high p27 staining showed that low protein levels of p27 were associated with a shortened disease-free and overall survival (P< 0.0001 and P< 0.0001, respectively). Similarly, low staining of cyclin E and high Ki-67 index correlated with a shortened disease-free and overall survival. On multivariate analysis using Cox proportional hazards model, low protein levels of p27 and high Ki-67 index were independent predictors of shortened disease-free (P< 0.0001, P = 0.0031, respectively), and low protein levels of p27, low staining of cyclin E and high Ki-67 index of overall survival (P = 0.0017, P = 0.0009, P = 0.0003, respectively). In superficial bladder tumours (Ta, T1; 86 patients), significant correlations were observed between low p27 staining and high Ki-67 index and early recurrence (P = 0.0048, P = 0.0178, respectively). Among the recurrenced superficial tumours (35 patients), the tumours which remained at a low stage showed high protein levels of p27 and cyclin E, and the tumours which progressed to invasive disease showed a gradual decrease in p27 and cyclin E protein levels over time. Our findings suggest that decreased protein levels of p27 and cyclin E play a role in the progression of bladder cancer and to evaluate these protein levels may be useful in management of the diseases.     

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.     

Prognostic Impact of Cyclin D1, Cyclin E and P53 on Gastroenteropancreatic Neuroendocrine Tumours

Conventional classifications of gastroenteropancreatic neuroendocrine tumours (GEP- NETs) are ratherunsatisfactory because of the variation in survival within each subgroup. Molecular markers are being foundable to predict patient outcome in more and more tumours. The aim of this study was to characterize theexpression of the proteins cyclin D1, cyclin E and P53 in GEP- NETs and assess any prognostic impact. Tumorspecimens from 68 patients with a complete follow-up were studied immunohistochemically for cyclin D1, cyclinE and P53 expression. High cyclin D1 and cyclin E immunostaining (≥ 5% positive nuclei) was found in 48(71%) and 24 (35%) cases, and high P53 staining (≥ 10% positive nuclei) in 33 (49%) . High expression of P53was more common in gastric neuroendocrine tumors and related to malignant behavior, being associate with aworse prognosis on univariate analysis (RR=1.9, 95%CI=1.1-3.2). High expression of cyclin E was significantlyassociated with shorter survival in the univariate analysis (RR=2.0, 95%CI=1.2-3.6) and multivariate analysis(RR=2.1, 95%CI=1.1-4.0). We found no significant correlation between the expression of cyclin D1 and anyclinicopathological variables. Our study indicated a prognostic relevance for cyclin E and P53 immunoreactivity.Cyclin E may be an independent prognostic factor from the 2010 WHO Classification which should be evaluatedin further studies.     

Cyclin D1, cyclin E, and p21 have no apparent prognostic value in anal carcinomas treated by radiotherapy with or without chemotherapy

The purpose of this study was to assess the potential prognostic and/or predictive value of the expression of cyclin D1, cyclin E, and p21 protein in a series of 98 anal carcinomas (T1-4, N0-3) treated by radiotherapy with (51) or without (47) chemotherapy in one institution. Correlation with Mib1 index and p53 expression was also investigated. Median follow-up for surviving patients was 124 months (range: 30-266). Immunohistochemical staining was performed on pretreatment biopsies, applying a standard ABC technique for cyclin D1 (clone DSC6, DAKO, 1 : 300), cyclin E (clone 13A3, Novocastra, 1 : 100), p21(WAF/CIP1) (clone SX118, DAKO, 1 : 50), p53 (clone DO7, DAKO, 1 : 200), and Mib1 (Ki-67, Dianova, 1 : 20). Tumours were classified into low- or high-expression groups according to the expression level of the protein considered. High expression was found in 51% of tumours for cyclin E, in 33.7% for cyclin D1, and in 65% for p21. None of those factors were significantly associated with clinical variables such as advanced T or N categories. In a monovariate analysis, advanced T and N categories and longer overall treatment time were the only variables that correlated significantly with low rate of local control (LC) and disease-free survival. However, in a subgroup analysis, high p21 expression correlated with a trend for significantly higher 5-year LC (87 vs 68%, P=0.07) in the N0 patients. The results of this study suggest that the cell-cycle proteins investigated are unlikely to be clinically useful in predicting treatment response or prognosis in patients with anal carcinomas.     

Paradoxical correlations of cyclin-dependent kinase inhibitors p21waf1/cip1 and p27kip1 in metastatic colorectal carcinoma.

The cyclin-dependent kinase inhibitors (CDIs) p27kip1 and p21waf1/cip1 are key cell cycle-negative regulatory enzymes. The objective of this study was to correlate expression of p27kip1 and p21waf1/cip1 with survival, chemotherapy responsiveness, and expression of the proliferation marker Ki-67 in patients with advanced colorectal cancer. Immunohistochemistry was performed with antibodies to p27kip1, p21waf1/cip1, and Ki-67 on samples from 66 patients with metastatic colorectal carcinoma. Interpretation was performed by visual inspection and automated image analysis. Patients who obtained a response to chemotherapy had greater p21waf1/cip1 tumor staining with a mean of 10.0 positive cells/high-powered field, compared with 4.5 positive cells/high-powered field for nonresponders (P = 0.03). A positive Spearman correlation was seen between Ki-67 and p27kip1 (r = 0.48; P = 0.0001), as well as between Ki-67 and p21waf1/cip1 (r = 0.48; P = 0.0001). A trend toward shorter survival was seen in patients with positive specimens (median survival of 10 months for patients with both p27kip1- and p21waf1/cip1-positive specimens, compared with 22 months for patients with neither p27kip1- nor p21waf1/cip1-positive specimens). In contrast to that previously reported in normal colonic mucosa or early-stage colorectal cancer, we observed positive correlations of Ki-67 with both p27kip1 and p21waf1/cip1, a trend toward greater CDI staining indicating worse prognosis, and greater p21waf1/cip1 staining in tumors that were chemosensitive. These findings suggest that in the metastatic setting, CDIs may show altered function, compared with their role in the normal cell cycle.     

Additive effects of tamoxifen and the farnesyl transferase inhibitor FTI-277 on inhibition of MCF-7 breast cancer cell-cycle progression

The efficacy of tamoxifen in the hormonal therapy of breast cancer is well established, but therapeutic resistance is inevitable. FTIs are a new class of anticancer drugs that are in phase III clinical evaluation. Since the mechanisms of action of these 2 classes of drugs are different, we tested the combination of tamoxifen and FTI-277 on inhibiting proliferation of hormone-dependent MCF-7 human breast cancer cells. An additive effect on cell proliferation was demonstrated, accompanied by an additive G(0)/G(1) arrest. The major effect of the combination of the 2 drugs was to maintain p21(waf/cip1) at an intermediate level, higher than that observed in the presence of tamoxifen alone. This was associated with an additive effect on inactivation of cyclin E-Cdk2 complexes and decreased phosphorylation of pRb and p130 pocket proteins. These effects were accompanied by increased association of 2 CDIs, p27(kip1) and p21(waf/cip1), with cyclin E-Cdk2 complexes. These data demonstrate that the additive effect is likely predominantly due to the recruitment of p27(kip1) and, to a lesser extent, p21(waf/cip1) into the cyclin E-Cdk2 complexes. Together, these results suggest that the combination of FTI and tamoxifen may increase the antitumor effect of either drug alone in breast cancer.     

G1 checkpoint protein and p53 abnormalities occur in most invasive transitional cell carcinomas of the urinary bladder.

The G1 cell cycle checkpoint regulates entry into S phase for normal cells. Components of the G1 checkpoint, including retinoblastoma (Rb) protein, cyclin D1 and p16INK4a, are commonly altered in human malignancies, abrogating cell cycle control. Using immunohistochemistry, we examined 79 invasive transitional cell carcinomas of the urinary bladder treated by cystectomy, for loss of Rb or p16INK4a protein and for cyclin D1 overexpression. As p53 is also involved in cell cycle control, its expression was studied as well. Rb protein loss occurred in 23/79 cases (29%); it was inversely correlated with loss of p16INK4a, which occurred in 15/79 cases (19%). One biphenotypic case, with Rb+p16- and Rb-p16+ areas, was identified as well. Cyclin D1 was overexpressed in 21/79 carcinomas (27%), all of which retained Rb protein. Fifty of 79 tumours (63%) showed aberrant accumulation of p53 protein; p53 staining did not correlate with Rb, p16INK4a, or cyclin D1 status. Overall, 70% of bladder carcinomas showed abnormalities in one or more of the intrinsic proteins of the G1 checkpoint (Rb, p16INK4a and cyclin D1). Only 15% of all bladder carcinomas (12/79) showed a normal phenotype for all four proteins. In a multivariate survival analysis, cyclin D1 overexpression was linked to less aggressive disease and relatively favourable outcome. In our series, Rb, p16INK4a and p53 status did not reach statistical significance as prognostic factors. In conclusion, G1 restriction point defects can be identified in the majority of bladder carcinomas. Our findings support the hypothesis that cyclin D1 and p16INK4a can cooperate to dysregulate the cell cycle, but that loss of Rb protein abolishes the G1 checkpoint completely, removing any selective advantage for cells that alter additional cell cycle proteins.     

Immunohistochemical study of cell cycle-associated proteins in adenocarcinoma of the uterine cervix treated with radiotherapy alone: P53 status has a strong impact on prognosis

PURPOSE: Because the incidence of adenocarcinoma of the uterine cervix has recently risen, the evaluation of radiotherapy (RT) for this disease has become an increasingly urgent matter. We analyzed the expression of the cell cycle-associated proteins p53, p27, p21/waf1/cip1, and cyclin D1 in cervical adenocarcinomas in correlation with the prognostic significance in tumors treated with RT alone. METHODS AND MATERIALS: The expression of p53, p27, p21/waf1/cip1, and cyclin D1 was studied using an immunohistochemical method in 53 cases of cervical adenocarcinoma treated only with RT. Patients received RT alone between 1965 and 1994. The mean patient age was 61.8 +/- 12.6 years (range, 36-82 years). The number of patients with Stage I, II, III, and IVA disease was 6, 16, 28, and 3, respectively. RESULTS: The number of patients with p53, p27, p21/waf1/cip1, and cyclin D1 positive tumors was 24, 18, 22, and 8, respectively; no statistically significant correlation was noted. The 5-year disease-free survival rate of p53-positive patients was 30%, significantly lower than the 62% for the p53-negative patients (p = 0.02); no statistically significant correlation was noted between disease-free survival and p27, p21/waf1/cip1, and cyclin D1 expression. No statistically significant correlation was observed between local control and expression of any of the proteins. CONCLUSION: Expression of p53 protein has a statistically significant impact on disease-free survival in adenocarcinoma of the uterine cervix treated with RT alone. However, the clinical significance of p27, p21/waf1/cip1, and cyclin D1 protein expression was not obvious.     

Cyclin D1 expression in non-small-cell lung cancers: its association with altered p53 expression, cell proliferation and clinical outcome.

Cyclin D1, like p16INK4 (p16) and retinoblastoma (RB) proteins, participates in the cell cycle control at the G1-S transition. We have previously demonstrated altered p16 and RB protein status in non-small-cell lung cancers (NSCLCs) and their potential synergistic effect with altered p53 protein on proliferative activity (Kinoshita et al (1996) Cancer Res 56: 5557-5562). In the present study, cyclin D1 expression was studied by immunohistochemistry in the same cohort of 111 resected NSCLCs as in our previous study, and the amount of the cyclin D1 gene was analysed by Southern blot analysis in 29 NSCLCs. Cyclin D1 expression was analysed in relation to the status of p53, p16 and RB proteins, and proliferative activity determined by the Ki-67 index. It was also analysed in relation to survival of 77 patients with NSCLCs which were potentially curatively resected between 1990 and 1995. We found that: (1) cyclin D1 was expressed in 13 (11.7%) of 111 NSCLCs; (2) the cyclin D1 gene was neither significantly amplified nor rearranged; (3) cyclin D1 expression significantly correlated with altered p53 protein expression (P = 0.04), whereas it did not correlate with p16 and RB protein status; (4) proliferative activity tended to be higher in cyclin D1-positive (+) tumours than in cyclin D1-negative (-) tumours, although this difference was not statistically significant (P = 0.08); and (5) patients with cyclin D1+ tumours survived longer than patients with cyclin D1- tumours (5-year survival rates, 89% and 64% respectively, by the Kaplan-Meier method; P = 0.045 by the log-rank test), and cyclin D1 expression tended to be a favourable prognostic factor (P = 0.08 in univariate analysis). These findings suggest the involvement of cyclin D1 in the development and progression of NSCLCs, their proliferative activity and clinical outcome of NSCLC patients.     

Subcellular localisation of cyclin D1 protein in colorectal tumours is associated with p21(WAF1/CIP1) expression and correlates with patient survival

We investigated the expression of the cell cycle regulatory proteins cyclin D1 and p21(WAF1/CIP1) (p21) in human colorectal carcinomas using immunohistochemistry. Cyclin D1 was not detected in normal colonic epithelium; however, expression was observed in 74/126 (58.7%) of the tumour samples studied. Protein was detected in the nucleus in 22/126 (17.4%) and exclusively in the cytoplasm in 52/126 (41.3%) tumours. Nuclear expression of cyclin D1 was associated with poorly differentiated tumours (p = 0.035) and was more common in right- than in left-sided tumours (p = 0.005). Tumours displaying either, expression of cytoplasmic, (p = 0.05, HR 0.56, 95% CI 0.31-1.0) or nuclear (p = 0.021, HR 0.24, 95% CI 0.07-0.81) cyclin D1 were associated with improved patient survival compared with tumours negative for cyclin D1. p21 protein was strongly expressed mainly in the upper crypts of normal colonic epithelial cells, but in 63/126 (50%) of the tumour samples studied p21 expression was absent. Patients with tumours in which >50% of cells expressed p21 had improved survival compared to patients whose tumours were negative or had < or =50% of cells expressing p21 (p = 0.06, HR 0.33, 95% CI 0.1-1.0). We also observed a significant association between cyclin D1 subcellular localisation and p21 expression: 21/22 (95.5%) tumours expressing cyclin D1 in the nucleus also expressed p21, whereas only 17/52 (32.7%) of the tumours displaying exclusive cytoplasmic cyclin D1 staining were positive for p21 (p < 0.001). These data highlight the significance of exclusive cytoplasmic expression of cyclin D1 in colorectal cancer and lend support to recent in vitro studies suggesting that p21 protein may modulate the subcellular localisation of the cyclin D1 protein. Thus, deregulated expression of the cyclin D1 and p21 proteins are important in colorectal tumourigenesis and have implications for patient prognosis.     

p22/WAF1 expression in human colorectal carcinoma: association with p53, transcription factor AP-2 and prognosis

p21/WAF1 expression was studied in a series of 162 colorectal carcinoma patients and its relation to p53- and activator protein (AP)-2 expressions and to stage as well as survival was assessed. p21 expression was moderate or intense in 33% of the tumours, and 53% of the tumours had moderate or strong p53 staining intensity. Eighty-nine percent of the tumours showed a weak cytoplasmic AP-2 signal. As expected, p21 and p53 stainings were inversely related to each other (P < 0.001). There was a significant positive association between p21 and AP-2 expression levels (P= 0.01). p21 intensity and percentage were higher in Dukes' A and B stages (P< 0.001). The cancer-related survival and recurrence-free survival (RFS) rates were significantly lower among patients with a low signal for p21 (P< 0.001) and low p21 percentage in tumour epithelium (P < 0.001). High p53 staining intensity in tumour epithelium predicted poor survival (P = 0.01) and RFS (P = 0.003). In the multivariate analysis, p21 percentage distribution independently predicted cancer-related survival in all cases, and p21 expression intensity in T1-4/N0-3/M0 and T1-3/N0/M0 cases. p21 percentage distribution was an independent predictor of RFS in all and T1-3/N0/M0 cases. AP-2 staining did not reach any prognostic significance. These results suggest that the immunohistochemical detection of cyclin-dependent kinase inhibitor p21 could be used to predict more precisely the outcome of colorectal cancer patients.     

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.     

8-60hIPP5m-Induced G2/M Cell Cycle Arrest Involves Activation of ATM/p53/p21cip1/waf1 Pathways and Delayed Cyclin B1 Nuclear Translocation

Protein phosphatase 1 (PP1) is a major serine/threonine phosphatase that controls gene expression andcell cycle progression. The active mutant IPP5 (8-60hIPP5m), the latest member of the inhibitory molecules forPP1, has been shown to inhibit the growth of human cervix carcinoma cells (HeLa). In order to elucidate theunderlying mechanisms, the present study assessed overexpression of 8-60hIPP5m in HeLa cells. Flow cytometricand biochemical analyses showed that overexpression of 8-60hIPP5m induced G2/M-phase arrest, which wasaccompanied by the upregulation of cyclin B1 and phosphorylation of G2/M-phase proteins ATM, p53, p21cip1/waf1and Cdc2, suggesting that 8-60hIPP5m induces G2/M arrest through activation of the ATM/p53/p21cip1/waf1/Cdc2/cyclin B1 pathways. We further showed that overexpression of 8-60hIPP5m led to delayed nuclear translocationof cyclin B1. 8-60hIPP5m also could translocate to the nucleus in G2/M phase and interact with pp1α and Cdc2as demonstrated by co-precipitation assay. Taken together, our data demonstrate a novel role for 8-60hIPP5min regulation of cell cycle in HeLa cells, possibly contributing to the development of new therapeutic strategiesfor cervix carcinoma.     

Role of cyclin D1 in ErbB2-positive breast cancer and tamoxifen resistance

Cyclin D1 plays an important role in the regulation of the G1 phase in the cell cycle. In mammary epithelial cells the expression of cyclin D1 is regulated through the oestrogen receptor and via ErbB2 signalling. Here we investigated the prognostic significance of cyclin D1 among 230 breast cancer patients randomised for tamoxifen, CMF chemotherapy and radiotherapy. The importance of combined cyclin D1 and ErbB2 overexpression was also analysed. Immunohistochemical analysis of the cyclin D1 expression resulted in 69 (29.8%) weakly positive, 107 (46.5%) moderately positive and 54 (23.7%) strongly positive cases. The prognostic importance of ErbB2 was significantly greater for patients whose tumours overexpressed cyclin D1 than for other patients (p = 0.026). In the former group, ErbB2 overexpression was strongly associated with increased risk of recurrence (RR = 4.7; 95% CI, 2.1–10.4) and breast cancer death (RR = 5.4; 95% CI, 2.3–12.6). This result is in accordance with experimental studies demonstrating a link between cyclin D1 and ErbB2 in oncogenesis. Among oestrogen receptor positive patients, those with moderate cyclin D1 expression significantly did benefit from tamoxifen treatment (RR = 0.42; 95% CI, 0.21–0.82) whereas those with weak or strong expression did not. Therefore cyclin D1 might be a predictive marker for tamoxifen resistance.     

FHIT、p21waf1/cip1基因在膀胱移行细胞癌中的表达与意义

目的:通过测定脆性组氨酸三联体基因(FHIT)及p21waf1/cip1基因在膀胱移行细胞癌组织、正常膀胱组织中的表达,探讨FHIT基因以及p21waf1/cip1基因与膀胱癌的关系及其临床意义。方法:采用免疫组织化学SP法对43例膀胱移行细胞癌(BTCC)组织及14例正常膀胱组织中的FHIT基因及p21waf1/cip1基因的蛋白表达进行检测。结果:FHIT蛋白表达与肿瘤的分期、分级无相关性(P>0.05)而p21waf1/cip1蛋白的表达与之有相关性(P<0.05);FHIT蛋白的表达在GI肿瘤、浅表性肿瘤中明显低于在正常膀胱组织中的表达(P<0.05)而p21waf1/cip1蛋白的表达在上述组织比较中无差别(P>0.05);FHIT蛋白的表达在初发肿瘤中与复发肿瘤中无明显差别(P>0.05)而p21waf1/cip1蛋白的表达在上述两种组织比较有明显差别(P<0.05)。FHIT蛋白与p21waf1/cip1蛋白的表达没有相关性(P>0.05)。结论:FHIT基因可能成为早期诊断膀胱移行细胞癌的指标。p21waf1/cip1基因可能成为估计膀胱移行细胞癌的恶性程度及肿瘤侵袭性、预后的指标。FHIT基因在膀胱移行细胞癌中的作用机制可能与p21waf1/cip1基因没有关系。     

Prognostic impact of p21/waf1/cip1 in colorectal cancer

In addition to the tumor suppressor gene p53, Cyclin Dependent Kinases (CDK) are well known to influence the cell cycle in normal human tissues and various neoplasias as well. The purpose of our present study was to evaluate the expression of the CDK-inhibitor p21/waf1/cip1 in colorectal cancer with special emphasis on the prognostic impact. Between 1985 and 1991, 294 patients (median age, 65 years) underwent surgical operative therapy for colorectal cancer. Formalin-fixed and paraffin-embedded tumor specimens were investigated. For immunohistochemistry the Catalysed Reporter Deposition (CARD) technique was performed. The survival probability was calculated and possible prognostic risk factors were tested using multivariate analysis. The p21/ waf1/cip1 staining pattern was positive in 197 (67%) specimens and negative in 97 (33%) samples. No significant correlation could been calculated between p21/waf1/cip1 expression and other variables such as age, sex, WHO-Classification, localisation, grading, TNM-classification or UICC-stage. Patients with a positive staining reaction had a significantly better survival (p < 0.0052). Moreover, p21/waf1/cip1 was shown to be an independent prognostic parameter by multivariate analysis (p < 0.022). In contrast with these findings, the p53 tumor status had no impact on survival. P21/ waf1/cip1 appears to be an independent prognostic parameter in colorectal cancer and is associated with a favorable survival. This feature may be related to a cell cycle arrest in the G1 phase induced by p21/waf1/cip1, resulting in lower tumor cell proliferative activity.     

Estrogens decrease gamma-ray-induced senescence and maintain cell cycle progression in breast cancer cells independently of p53

PURPOSE: Sequential administration of radiotherapy and endocrine therapy is considered to be a standard adjuvant treatment of breast cancer. Recent clinical reports suggest that radiotherapy could be more efficient in association with endocrine therapy. The aim of this study was to evaluate the estrogen effects on irradiated breast cancer cells (IR-cells). METHODS AND MATERIALS: Using functional genomic analysis, we examined the effects of 17-beta-estradiol (E(2), a natural estrogen) on MCF-7 breast cancer cells. RESULTS: Our results showed that E(2) sustained the growth of IR-cells. Specifically, estrogens prevented cell cycle blockade induced by gamma-rays, and no modification of apoptotic rate was detected. In IR-cells we observed the induction of genes involved in premature senescence and cell cycle progression and investigated the effects of E(2) on the p53/p21(waf1/cip1)/Rb pathways. We found that E(2) did not affect p53 activation but it decreased cyclin E binding to p21(waf1/cip1) and sustained downstream Rb hyperphosphorylation by functional inactivation of p21(waf1/cip1). We suggest that Rb inactivation could decrease senescence and allow cell cycle progression in IR-cells. CONCLUSION: These results may help to elucidate the molecular mechanism underlying the maintenance of breast cancer cell growth by E(2) after irradiation-induced damage. They also offer clinicians a rational basis for the sequential administration of ionizing radiation and endocrine therapies.