Cell Proliferation Markers

Factors involved in cell cycle regulation that, in addition to p14ARF/MDM2/p53 and/or p16INK4a/cyclin D/Rb (see above), have been investigated in penile cancer include proliferation cell nuclear antigen (PCNA) and Ki-67. PCNA is a protein found in the nucleus of cells and is a cofactor of DNA polymerase delta. PCNA is important for both DNA synthesis and DNA repair. Expression of PCNA has been evaluated in penile cancer with different results.28,53,54 Both no correlation between PCNA immuno-expression and prognosis, and PCNA as an independent factor for the presence of lymph node metastasis have been reported. It is likely that these findings are related to a difference in execution and interpretation of PCNA immu-nostaining, e.g., tissue fixation, antibody dilution, and cut off points. Accordingly, the application of PCNA as a prognostic factor must be evaluated with care. Ki-67 is a nuclear protein encoded by the MK167 gene and a cellular marker for proliferation. Ki-67 expression has been found correlated with tumor type, with the highest expression in basaloid carcinomas and the lowest in verrucous carcinomas.55-58 Despite the fact that Ki-67 immunostaining results are more consistent as for PCNA, also Ki-67 findings in relation to penile cancer are diverse. Reports vary from an inverse relation between Ki-67 expression and lymph node metastasis to no relationship with biologic behavior or lymph node metastasis to positive correlation between tumor stage, progression, and lymph node metastasis.54,59-63 Clearly, these findings need further evaluation.

Dealing With Erectile Dysfunction

Dealing With Erectile Dysfunction

Whether you call it erectile dysfunction, ED, impotence, or any number of slang terms, erection problems are something many men have to face during the course of their lifetimes.

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