p21 expression in colorectal carcinomas: a study on 103 cases with analysis of p53 gene mutation/expression and clinic-pathological correlations

Expression patterns of cyclins D1, E and cyclin-dependent kinase inhibitors p21waf1/cip1, p27kip1 in colorectal carcinoma: correlation with other cell cycle regulators (pRb, p53 and Ki-67 and PCNA) and clinicopathological features

Aberrations in the cell cycle regulators are common features of many tumours and several have been shown to have prognostic significant in colorectal cancer. The expression patterns of cyclins D1 and E as well as cyclin-dependent kinase (CDK) inhibitors p21waf1/cip1 and p27kip1 and their interrelationship with other cell cycle checkpoint proteins [p53, pRb, Ki-67 and proliferative cell nuclear antigen (PCNA)] were investigated in colorectal cancer in order to ascertain coregulation and influence on tumour behaviour or survival. These molecular markers were localisated immunohistochemically using the monoclonal antibodies anticyclin D1 (DCS-6), anticyclin E (13A3), anti-p21 (4D10), anti-p27 (1B4), anti-p53 (DO7), anti-Rb (AB-5), MIB1 and PC10 in colorectal cancer tissue from 97 patients. Data were analysed statistically using the spss software program. Overexpression of cyclin D1, cyclin E and p21waf1/cip1 proteins (>5% positive neoplastic cells) was observed in 5.9%, 30% and 7.2% of the cases respectively. Increased levels of cyclin D1 (p = 0.0001) and p21waf1/cip1 protein (p = 0.03) in tumours with mucous differentiation were observed. Overexpression of cyclin D1 was correlated with tumour stage (p = 0.03), the lymph node involvement (p = 0.02), as well as p21waf1/cip1 protein expression (p < 0.0001). Cyclin E was positively correlated with p21waf1/cip1 (p = 0.014), as well as with the cell proliferation as measured by PCNA-labelling index (p = 0.011) and Ki-67 score (p = 0.007). A positive relationship of p21waf1/cip1 expression with the proliferative-associated index Ki-67 was noted (p = 0.005). Downregulation of p27kip1 was observed in 47.4% of the cases and was correlated with downregulation of pRb (p = 0.002) and PCNA score (p = 0.004). The prognostic significance of cyclins D1, E and CDK inhibitors p21waf1/cip1, p27kip1 in determining the risk of recurrence and overall survival with both univariate (long-rang test) and multivariate (Cox regression) methods of analysis showed no statistically significance differences. In conclusion, these findings suggest that, the levels of the cell cycle regulators studied, do not seems to have a prognostic value, in terms of predicting the risk of early recurrence and overall survival. In addition, the interrelationships, probably means their contribution to the regulation of cell growth, through different pathways in colorectal carcinogenesis.

hTERT expression in colorectal adenocarcinoma: correlations with p21, p53 expressions and clinicopathological features

BACKGROUND

The clinicopathological roles and relationships of hTERT, p21 and p53 proteins have not been studied in depth in colorectal cancer. The aim of the present study is to investigate the clinicopathological roles of expression of hTERT protein expression and its relationship with the expression of p21 and p53 proteins in a large cohort of patients with colorectal adenocarcinoma.

MATERIALS AND METHODS

Expressions of hTERT, p21 and p53 proteins were investigated in 188 patients with colorectal adenocarcinomas by immunohistochemistry. The findings were correlated with the clinicopathological features and survival data of colorectal adenocarcinomas.

RESULTS

hTERT, p53 and p21 proteins were detected in 63%, 100% and 62% of the patients with colorectal carcinoma. High level of hTERT protein expression was noted in patients with metastases (p = 0.038) and in patients with rectal cancer (p = 0.046). Loss or low level of p21 protein was often noted in non-mucinous colorectal adenocarcinoma when compared with mucinous adenocarcinoma (p = 0.001). Furthermore, p53 expression was more frequently noted in non-mucinous adenocarcinoma (p = 0.001). The level of expression of p21 protein was positively correlated with expression of level of hTERT protein (p = 0.00001). The survival of the patients was related to staging (p = 0.001) and p53 protein expression (p = 0.038) of the tumours.

CONCLUSIONS

hTERT protein expression is an indicator of the biological aggressiveness of the cancer. The level of expression of the protein was also related to the distal location and level of p21 expression of the tumours.

P21WAF1/CIP1 expression in colorectal carcinomas is related to Kras mutations and prognosis

BACKGROUND/AIM

P21WAF1/CIP1 is a cyclin-dependent kinase inhibitor activated by p53 to produce cell cycle arrest. A consensus has not been reached concerning the prognostic value of p21WAF1/CIP1 expression in colorectal cancers.

PATIENTS/METHODS

P21WAF1/CIP1 expression was determined immunohistochemically in a series of 211 cases of colorectal carcinomas, together with its relation to p53, bcl-2, cell turnover (as assessed by Ki67 expression and apoptotic counts) and the Kras gene status. The expression of p21WAF1/CIP1 was also compared with reference to clinicopathological parameters and patient survival.

RESULTS

The median value for nuclear p21WAF1/CIP1 expression was 31% (interquartile range, 13-47%) and the fraction of cases considered to be high expressers (>20%) was 66%. Expression of p21WAF1/CIP1 was not associated with immunoreactivity for p53 or bcl-2, or cell turnover. P21WAF1/CIP1 high-expressing tumors were more often well differentiated (P<0.001), node-negative (P=0.037), Dukes' B (P=0.027) and Kras gene-mutated cases (P=0.04). On univariate analysis, low p21WAF1/CIP1 expressers (<or=20%) had lower cancer-related survival as compared with high expressers (5-year survival, 56 vs. 70%; P=0.042). Lymph node status, liver metastasis and tumor size were also significant predictors. Multivariate analysis revealed lymph node-positive (P<0.001), liver metastasis (P<0.001), and low p21WAF1/CIP1 expression (P=0.017) to be independent predictors of short survival.

CONCLUSION

The regulation of p21WAF1/CIP1, independent of p53 or bcl-2 expression, appears to be associated with Kras mutations. The immunohistochemical detection of p21WAF1/CIP11 might thus be used to predict more precise outcome in colorectal cancer patients.

Immunohistochemical expression of cyclin D1, cyclin E, p21/waf1 and p27/kip1 in inflammatory bowel disease: correlation with other cell-cycle-related proteins (Rb, p53, ki-67 and PCNA) and clinicopathological features

BACKGROUND AND AIMS

The expression patterns of cyclins D1 and E as well as cyclin-dependent kinase inhibitors p21/waf1 and p27/kip1 and their correlation with clinical parameters and other cell cycle regulators was investigated in inflammatory bowel disease (IBD).

PATIENTS AND METHODS

These molecular markers were localized immunohistochemically using the monoclonal antibodies anti-cyclin D1 (DCS-6), anti-cyclin E (13A3), anti-p21 (4D10) and anti-p27 (1B4) in 70 patients with IBD, 30 patients with colorectal cancer and eight healthy subjects. Data were analyzed statistically using the software program.

RESULTS

Cyclin D1 expression was higher in both UC and CD compared with the healthy control group. In addition, CD cyclin D1 expression was higher compared with UC cases and colorectal carcinomas. Cyclin D1 expression was correlated with disease activity and cell proliferation in UC cases. A positive relationship of cyclin D1 with p27/kip1 in both UC and CD was detected. Cyclin E expression was higher in UC, CD and carcinomas compared with healthy control group and its expression correlated with proliferative activity in both UC and CD cases. p21/waf1 expression was higher in IBD cases compared with that of the control group, while a decreased p21/waf1 expression in the group of carcinomas was noted. This expression was correlated with disease activity in UC and the proliferative activity in both UC and CD. The expression of cyclins D1 and E as well as p21/waf1 was also correlated with the existence of dysplastic lesions. A lower p27/kip1 expression in the group of carcinomas compared with IBD cases and healthy controls was found.

CONCLUSIONS

The expression patterns of cyclin D1, cyclin E, p21/waf1 and p27/kip1 in IBD may indicate their contribution in epithelial cell turnover and their possible implication in IBD-related dysplasia-carcinoma.

Poor prognosis of colorectal cancer in patients over 80 years old is associated with down-regulation of tumor suppressor genes

GOALS, BACKGROUND: The elderly population has been increasing during the last half a century and it would be important to know how aging influences the occurrence and biologic behavior of cancers.

STUDY

We investigated clinicopathologic characteristics of colorectal cancer in 1354 patients who underwent colorectal cancer resection and compared the results between extremely elderly patients (over 80 years old) and middle-aged/elderly patients (40 to less than 80 years old). Furthermore, we also examined expression of tumor suppressor genes and Cox-2 using frozen samples of colorectal cancer obtained from 62 patients ranging in age from 45 to 87 years.

RESULTS

The results obtained in the extremely aged patients were: (1) higher ratio of women, (2) higher incidence at the proximal site, (3) higher incidence of cases with deeper invasion, (4) higher incidence of cases with lymph node metastasis (5) poorer survival rate as compared with middle-aged/elderly patients, and (6) lower mRNA expression levels of p27 and p53.

CONCLUSIONS

These findings taken together suggest that poor prognosis of colorectal cancer in patients over 80 years is associated with down-regulation of mRNA expression of some tumor suppressor genes.

Cyclin D1 and p21 in ulcerative colitis-related inflammation and epithelial neoplasia: a study of aberrant expression and underlying mechanisms

It is unclear whether and how cyclin D1 and/or p21(WAF1/CIP1) dysregulation contribute to ulcerative colitis (UC)-related inflammation and colorectal carcinogenesis. Cases of quiescent UC (QUC; n = 15), active UC (AUC; n = 23), UC-related dysplasia (n = 35) and UC-related colorectal adenocarcinomas (CRCs; n = 11) were studied with cyclin D1 and p21(WAF1/CIP1) immunohistochemistry. The CRCs were also studied with beta-catenin, bcl2, and p53 immunohistochemistry, p53 and k-ras mutation analyses, and cyclin D1 gene fluorescence in situ hybridization. QUC showed cyclin D1 (negative/weak staining) and p21(WAF1/CIP1) (surface epithelial and upper-third crypt staining) expression similar to that of normal colorectum. Moderate or strong cyclin D1 immunostaining was seen in 9% of AUC cases, 40% of dysplasia cases, and 36% of UC-related CRCs. Although these carcinomas showed neither cyclin D1 gene amplification nor any association between k-ras mutation and cyclin D1 overexpression, the latter was closely related to nuclear beta-catenin expression. Increased lower-third crypt p21(WAF1/CIP1) staining was seen in 57% of AUC cases; decreased upper-third crypt p21(WAF1/CIP1) staining, in 23% of dysplasia cases; and absent or weak p21(WAF1/CIP1) staining, in 55% of UC-related CRCs. The latter change was always associated with p53 mutation but could not be related to p53 or bcl2 expression. In conclusion, AUC shows up-regulated cyclin D1 and p21(WAF1/CIP1) expression. Cyclin D1 up-regulation and p21(WAF1/CIP1) down-regulation occur early in UC-related carcinogenesis. Cyclin D1 up-regulation is less common in UC-related CRCs than in sporadic CRCs, and is related to beta-catenin nuclear signaling. p21(WAF1/CIP1) down-regulation is seen at an equal or higher frequency among UC-related CRCs compared with sporadic CRCs and is attributable to p53 mutation.

Clinical and pathologic relevance of p53 index in canine osseous tumors

The clinicopathologic value of the immunohistochemical (IHC) expression of p53 protein was evaluated in 167 canine osseous tumors. p53 staining frequency and intensity in tumor cells was expressed as a p53 index. p53 index was significantly higher in osteosarcomas than in other sarcomas, chondrosarcoma, multilobular tumor of bone, and tumors initially misdiagnosed as osteosarcomas as well as in appendicular versus axial and in distal versus proximal osteosarcomas. A strong correlation is demonstrated between the p53 index and a range of clinicopathologic parameters in osteosarcoma, including the tumor site, histologic grade and score, mitotic index, degree of tumor necrosis, and pleomorphism. Chondroblastic osteosarcomas had significantly higher and telangiectatic osteosarcomas significantly lower p53 index than did osteosarcomas belonging to other histopathologic subtypes, a fact that tends to reinforce the perception of these osteosarcomas as distinct clinicopathologic entities. Entire males had higher p53 index than did neutered males. p53 index was higher in Rottweilers than in Great Danes and Terriers, confirming breed susceptibilities to osteosarcoma. p53 index showed no association with age, primary or secondary site status, or the presence of metastases or other tumor types. Biopsy samples had a higher p53 index than did postmortem samples, either because of differences in sample processing or the possibility that p53 overexpression is more evident at the earlier stages of osteosarcoma pathogenesis, presumably represented by the biopsy material. IHC examination for p53 and the derived index has the potential to be used as an additional diagnostic tool and prognostic indicator for osseous tumors.

Prognostic significance of p21 and p27 protein, apoptosis, clinical and histologic factors in rectal cancer without lymph node metastases

The aim of this study was to evaluate the prognostic role of clinical and histopathologic factors, cell-cycle regulator proteins (p21(Waf1/Cip1), p27(Kip1)), and apoptotic index in lymph node-negative rectal cancer. Formalin-fixed, paraffin-embedded tissue samples of 97 rectal carcinomas (UICC stages I and II) resected curatively within five years were used. Immunohistochemical analysis of protein expression was performed by monoclonal antibodies: p21 (clone SX118), p27 (clone SX53G8). Apoptosis was assessed by the TUNEL method. Clinical, surgical, histopathologic, and follow-up data were prospectively recorded in a computerized registry. To assess prognostic significance (end points: metachronous distant metastases, 5-year disease-free and overall survival), statistics included univariate and multivariate analysis (p < 0.05 statistically significant). Of the 97 rectal carcinomas without lymph node metastases, 46.4% (45/97) were p21-positive, 49.5% were p27-positive (48/97), whereas 27.8% (27/97) showed a high apoptotic index. Within a median follow-up of 54 months, 4 patients developed local recurrence (4.1%). Distant metastases occurred in 12 patients (12.4%). Univariate analysis showed that gender, UICC stage, p21 and p27 were significantly associated with the incidence of distant metastases (p < 0.05). UICC stage and p21 were the only factors to be significantly related to 5-year disease-free survival by univariate analysis (p < 0.05). Only UICC stage was significantly related to 5-year overall survival (p < 0.05). The apoptotic index was correlated neither to recurrence nor to survival (p > 0.05). Multivariate analysis demonstrated that gender, UICC stage and p21 were independently related to the incidence of distant metastases; however, UICC stage was the only independent factor predictive of 5-year disease-free survival and overall survival (p < 0.05).

Analysis of key cell-cycle checkpoint proteins in colorectal tumours

Aberrations in the components of cell-cycle checkpoints are a common feature of many tumours and several have been shown to have prognostic significance in colorectal cancer. In this study, seven components of cell-cycle control [cyclin D1, retinoblastoma (pRb), p21, p27, p16, p53, and proliferating cell nuclear antigen (PCNA)] were examined in a large series of well-characterized colorectal adenocarcinomas using immunohistochemistry to ascertain co-regulation and influence on survival. The majority (92%) of the tumours had abnormal staining of > or =2 cell-cycle control factors. Expression of cyclin D1 protein was correlated with both p21 (p<0.001) and p27 (p=0.033), suggesting co-regulation of these proteins in colorectal tumours. Only cyclin D1 (p=0.048) and p53 (p=0.025) were directly associated with PCNA levels, suggesting a more important role in the proliferative capacity of tumour cells. Significant associations between cell cycle-related proteins and clinicopathological data were observed: cyclin D1 and p53 proteins were correlated with patient age (p=0.042 and p<0.001, respectively) and p53 (p=0.01) and p21 (p=0.024) proteins were associated with tumour site. Expression of cyclin D1 protein was the only protein examined that was related to improved outcome in these patients (p=0.0266), but it was not an independent predictor of survival. These results suggest that loss of control of cell-cycle checkpoints is a common occurrence in colorectal tumours and may be an important therapeutic target.

P21 (WAF1) expression in colorectal cancer: correlation with P53 and cyclin D1 expression, clinicopathological parameters and prognosis

P21 (WAF1), P53 and cyclin D1 belong to the cell cycle-regulating family of proteins, and the loss of activity of proteins P53 and P21 (WAF1) seems to be one of the most important regulatory mechanisms of carcinogenesis in colorectal cancer. The purpose of this study was to assess the relationship between P21 (WAF1), P53 and cyclin D1 immunoreactivity, and to evaluate the prognostic significance of their expression. Tissue sections from 122 paraffin-embedded colorectal carcinomas were immunostained with monoclonal antibodies. Positivity for P21 (WAF1) was found in 48 cases (39%), positivity for P53 in 96 cases (70%) and positivity for cyclin D1 in all the cases (100%). Statistical analyses revealed a statistically significant inverse correlation between P53 and P21 (WAF1)-immunopositivity and between P21 (WAF1)-immunopositivity and the degree of cyclin D1-immunopositivity, as well as an inverse correlation between P21 (WAF1) expression and clinical stage. In univariate analysis, down-regulation of P21 (WAFI) expression was associated with poor prognosis, but multivariate analysis did not confirm its independent prognostic significance. In Cox's analysis only regional lymph node invasion and hepatic metastases were proven as independent prognostic parameters. Our investigation results suggest that in colorectal cancer, the induction of P21 (WAF1) may occur mostly in a P53-dependent pathway. P21 (WAF1), as the main cyclin-dependent kinase (CDK)-inhibitor, may also inhibit the activity of cyclins such as cyclin D1.

Differential expression of cdc25 cell-cycle-activating phosphatases in human colorectal carcinoma

cdc25 is a family of cell-cycle phosphatases that activate the cyclin-dependent kinases. cdc25A and B, but not C, have oncogenic potential in vitro. In this study, we analyzed the possible implication of cdc25 genes in the progression of colorectal tumors. RNA and DNA were extracted from 34 paired tumor and normal colorectal tissues and examined by Northern blot, RT-PCR, and Southern blot, respectively. Protein expression was analyzed by Western blot in a subset of normal and tumor samples. The expression levels were correlated with the clinicopathologic characteristics and survival of the patients. cdc25B mRNA was overexpressed in 19 carcinomas (56%). A significant correlation was observed between high cdc25B mRNA levels and the relapse-free, overall, and cancer-related survival of the patients. The cdc25B2 splicing variant was detected in 27 carcinomas (79%) but only in 9 normal samples (26%) and was associated with the grade of the differentiation of the tumors. cdc25A mRNA was overexpressed in four tumors (12%) and cdc25C1 mRNA was overexpressed in nine tumors (26%). A new cdc25C2 splicing variant lacking exon 4 and 5 was identified in all of the tumors and in 56% of the normal samples. No amplifications or gene rearrangements of these genes were detected. In conclusion, these findings indicate that cdc25 isoforms and splicing variants are differentially regulated in colorectal carcinomas and may participate in the development of these tumors. Additionally, the correlation between cdc25B mRNA levels and the survival of the patients also suggest that the cdc25B isoform may be involved in the progression of the disease.