Expression of the cyclin-dependent kinase inhibitor p27 in transitional cell bladder cancers: is it a good predictor for tumor behavior?

Assessment of survivin and p27 expression as potential prognostic markers in urothelial cell carcinoma of urinary bladder in Egyptian patients

Background

Bladder cancer (BC) is the tenth most common cancer worldwide with urothelial carcinoma (UC) being the main histologic subtype. Survivin is an apoptosis inhibitor that is associated with tumor proliferation and invasion. P27 is a cyclin-dependent kinase inhibitor that negatively regulates cell proliferation. The expression of both proteins was variable among different solid tumors including UC.

Methods

We aimed to investigate the expression of survivin and P27 in UC of urinary bladder and correlate their expressions with histopathological parameters in an attempt at studying the possibility of their use as targeted therapies. The investigation was performed through immunohistochemical staining for both proteins on sections belonging to 60 UCs and 12 mild chronic cystitis cases (controls). Immunopositivity (number of positive cases) and expression score (percentage of positive urothelial cells) were evaluated.

Results

Both survivin and P27 were absent in urothelial cells of mild chronic cystitis lesions while expressed in 60% and 43.3% of UCs, respectively. High score of survivin and low score of P27 were associated with poor prognostic factors of UC (solid pattern, high grade, and deep tumors). By logistic regression test, survivin expression can be a predictive risk factor associated with solid pattern and high-grade UC, while P27 expression can be a predictive risk factor associated low-grade UC.

Conclusion

High survivin and low P27 expression scores were associated with the studied prognostic factors of UC. Both proteins may play a role in UC progression and can have a value as prognostic and/or diagnostic markers of UC, as well as targeted therapies.

Significance of p57Kip2 Down-Regulation in Oncogenesis of Bladder Carcinoma: An Immunohistochemical Study

Aims and Background

Cyclin-dependent kinase inhibitors have important roles in the oncogenesis of various tumors including urothelial cancer. The aim of this study was to establish the importance of p57Kip2, a unique cyclin-dependent kinase inhibitor, in the oncogenesis of bladder carcinoma. This article also focused on another cyclin-dependent kinase inhibitor, p27Kip1, and telomerase enzyme and examined the relationship between these proteins.

Material and Methods

Thirty-one patients with urothelial carcinomas of the bladder and 7 cases with normal urinary bladder mucosa were included in the study. Immunohistochemical study was performed by monoclonal antibodies of p27Kip1, p57Kip2, and the telomerase subunit (hTERT). All immunohistochemical preparations were evaluated by an immunohistochemical histological score.

Results

p57Kip2 and p27Kip1 expression were seen in all of the cases of normal mucosa. In carcinoma cases, 8 of 31 (25.8%) showed p57Kip2 nuclear positivity and 20 of 31 (64.5%) expressed nuclear p27Kip1. HSCOREs of carcinoma cases showed lower scores of nuclear p57Kip2 and p27Kip1 than normal mucosa, but only HSCOREs of nuclear p57Kip2 (P = 0 001) showed statistical significance. Despite unknown significance, cytoplasmic p57Kip2 and p27Kip1 were also evaluated. Immunohistochemical analysis showed that carcinomas expressed higher HSCOREs of hTERT than normal mucosa, and there was a significant difference (P = 0.026) between muscle invasive carcinomas and normal mucosa.

Conclusions

The data showed that p57Kip2 down-regulation along with p27Kip1 is a well-established feature of urothelial carcinoma. Probably, this down-regulation of cyclin-dependent kinase inhibitors supports the proliferation phase of oncogenesis. In the study, we also showed that hTERT expression was up-regulated in higher stages of urothelial carcinoma.

Cyclin-dependent kinase inhibitor 3 (CDKN3) novel cell cycle computational network between human non-malignancy associated hepatitis/cirrhosis and hepatocellular carcinoma (HCC) transformation

The relationship of cyclin-dependent kinase inhibitor 3 (CDKN3) with tumours has previously been presented in a number of publications. However, the molecular network and interpretation of CDKN3 through the cell cycle between non-malignancy associated hepatitis/cirrhosis and hepatocellular carcinoma (HCC) have remained to be elucidated. Here, we have constructed and analysed significant high expression gene CDKN3 activated and inhibited cell cycle networks from 25 HCC versus 25 non-malignancy associated hepatitis/cirrhosis patients (viral infection HCV or HBV) in GEO Dataset GSE10140-10141, by combination of a gene regulatory network inference method based on linear programming, and decomposition procedure using CapitalBio MAS 3.0 software, based on integration of public databases including Gene Ontology, KEGG, BioCarta, GenMapp, Intact, UniGene, OMIM, and others. Comparing the same and differently activated and inhibited CDKN3 networks with GO analysis, between non-malignancy associated hepatitis/cirrhosis and HCC, our results suggest a CDKN3 cell cycle network (i) with stronger DNA replication and with weaker ubiquitin-dependent protein catabolism as common characteristics in both non-malignancy associated hepatitis/cirrhosis and HCC; (ii) with more cell division and weaker mitotic G2 checkpoint in non-malignancy associated hepatitis/cirrhosis; (iii) with stronger cell cycle and weaker cytokinesis, as a result forming multinucleate cells in HCC. Thus, it is useful to identify CDKN3 cell cycle networks for comprehension of molecular mechanism between non-malignancy associated hepatitis/cirrhosis and HCC transformation.

Susceptibility of p27 kip1 knockout mice to urinary bladder carcinogenesis induced by N-butyl-N-(4-hydroxybutyl)nitrosamine may not simply be due to enhanced proliferation

Deregulated proliferation is one of the fundamental characteristics of carcinogenesis. p27 is one of the most well characterized negative cell cycle regulator. In our previous study, expression of p27 protein was found to be dramatically suppressed on stimulation of cell proliferation by calculi in the rodent urinary bladder, withdrawal of the insult resulting in re-expression of p27 and regression of urothelial hyperplastic lesions. In the present study, to evaluate how loss of function impacts on urinary bladder carcinogenesis, N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN), a bladder carcinogen was given to p27 knockout mice. Males and females with either null, hetero or wild-type p27 alleles were divided into 2 groups, one given drinking water containing 0.05% BBN for 10 weeks and the other receiving distilled water, then, killed at week 20. The experiment was repeated for confirmation of the outcome. In the second experiment, performed with a larger number of animals, the incidence of urinary bladder carcinomas was significantly higher in female p27-null mice than in their wild-type counterparts. p27 deficiency also resulted in their increase of relative weights of urinary bladders and section areas of carcinomas in BBN-treated mice. Interestingly, while BrdU labeling indices generally increased with progression of mucosal proliferative lesions, from normal epithelium, through hyperplasia to carcinoma, there was no significant variation with the p27 genotype, in tumors as well as normal urothelium. These findings suggest that p27 deficient mice have elevated susceptibility to BBN-induction of urinary bladder carcinogenesis through a mechanism which might be independent of acceleration of cell cycling.

Large-scale analysis of cell cycle regulators in urothelial bladder cancer identifies p16 and p27 as potentially useful prognostic markers

AIMS

We investigated the value of multiple cell cycle markers for their prognostic impact on overall survival and recurrence-free survival in urothelial carcinoma (UC).

METHODS

A tissue microarray consisting of 99 UCs was evaluated for the expression of p53, p16, p21, p27, cyclin D1, cyclin E , Bcl-2, Ki-67 and PCNA. Statistical analysis was performed applying Kaplan-Meier and Cox regression models using receiver operator characteristic curves for determination of markers' cutoffs.

RESULTS

Expression above the cutoffs of Ki-67, p53 and p27, particularly in high-grade and early-stage UC, was associated with worse overall survival, while expression of p16 indicated a better outcome in low-grade and low-stage tumors. Recurrence-free survival was better in patients with high-grade UC expressing PCNA, p16 and cyclin E, and low-grade UC expressing Bcl-2 above the cutoffs, but worse in all tumors with high Ki-67.

CONCLUSION

Cell cycle deregulation in UC is complex and the prognostic value of the various involved proteins should be differentially regarded with respect to this complexity and other tumor characteristics such as grade and stage. Our results point towards the role of p16- and p27-associated pathways in tumor progression and indicate that, by using standardized approaches for tissue antigen expression, evaluation and cutoff determination, single potentially useful prognostic markers could be identified.