The Percentage of Free PSA and Urinary Markers Distinguish Prostate Cancer from Benign Hyperplasia and Contribute to a More Accurate Indication for Prostate Biopsy.

The main advantage of urinary biomarkers is their noninvasive character and the ability to detect multifocal prostate cancer (CaP). We have previously implemented a quadruplex assay of urinary markers into clinical practice (PCA3, AMACR, TRPM8 and MSMB with KLK3 normalization). In this study, we aimed to validate it in a larger cohort with serum PSA 2.5-10 ng/mL and test other selected transcripts and clinical parameters, including the percentage of free prostate-specific antigen (PSA) (% free PSA) and inflammation. In the main cohort of 299 men, we tested the quadruplex transcripts. In a subset of 146 men, we analyzed additional transcripts (CD45, EPCAM, EZH2, Ki67, PA2G4, PSGR, RHOA and TBP). After a prostate massage, the urine was collected, RNA isolated from a cell sediment and qRT-PCR performed. Ct values of KLK3 (i.e., PSA) were strongly correlated with Ct values of other genes which play a role in CaP (i.e., PCA3, AMACR, TRPM8, MSMB and PSGR). AMACR, PCA3, TRPM8 and EZH2 mRNA expression, as well as % free PSA, were significantly different for BPH and CaP. The best combined model (% free PSA plus PCA3 and AMACR) achieved an AUC of 0.728 in the main cohort. In the subset of patients, the best AUC 0.753 was achieved for the combination of PCA3, % free PSA, EPCAM and PSGR. PCA3 mRNA was increased in patients with inflammation, however, this did not affect the stratification of patients indicated for prostate biopsy. In conclusion, the percentage of free PSA and urinary markers contribute to a more accurate indication for prostate biopsy.

Tumour suppressor PTEN regulates cell cycle and protein kinase B/Akt pathway in breast cancer cells.

BACKGROUND: PTEN is a tumour suppressor protein with phosphatase activity frequently altered in several types of human cancers. MATERIALS AND METHODS: The PTEN effect was studied on the cell cycle (by bromdeoxyuridine incorporation) and on the phosphatidylinositol-3-kinase/protein kinase B/Akt (PI3-K/PKB/Akt) pathway regulating proteins (by immunocytochemical, Western blot analysis and kinase assay) upon transfection of wild-type PTEN and its mutant H123Y in breast cancer cell lines. RESULTS: The expression of the important proteins in the MCF-7 and BT-549 cells was characterised and the cellular localisation of PTEN was analysed. Transfection of H123Y led to the down-regulation of p27(Kip1) and p21(Waf1/Cip1) protein levels and the up-regulation of phosphorylated PKB/Akt. An overexpression of PTEN decreased cyclin E/cdk2 activity and inhibited S-phase entry in MCF-7. In BT-549 these changes were not observed, but overexpression of PTEN led to a diminution of PKB/Akt phosphorylation. CONCLUSION: PTEN function is mediated through the inhibition of the cell cycle and PKB/Akt phosphorylation in breast cancer cells.

The significance of key regulators of apoptosis in the development and prognosis of prostate carcinoma. I. Proteins of the Bcl-2 family and protein p53.

The molecular basis for the transition of carcinoma of the prostate from androgen-dependent to androgen-independent growth is largely unknown. Currently for example, it is not clear whether the androgen-independent phenotype is a result of selection of a subgroup of genetically distinct prostate tumour cells which are already hormone-resistant or a genetic adaptation of prostate tumour cells to the hormone therapy itself. It has also been established that prostate tumour transformation is a result of homeostatic control defects, a line of thinking directed toward elucidating the apoptotic profile of prostate tumour cells that may be important in determining prognosis, response to therapy and illness progression. Main consideration in this part of rewiev is given to the role of Bcl-2 and members of the Bcl-2 family, and tumour suppressor gene p53.

The significance of key regulators of apoptosis in the development and prognosis of prostate carcinoma. II. Products of suppressor genes Rb and PTEN, CDKI, Fas.

The molecular basis for the transition of carcinoma of the prostate from androgen-dependent to androgen-independent growth is largely unknown. Currently for example, it is not clear whether the androgen-independent phenotype is a result of selection of a subgroup of genetically distinct prostate tumour cells which are already hormone-resistant or a genetic adaptation of prostate tumour cells to the hormone therapy itself. It has also been established that prostate tumour transformation is a result of homeostatic control defects, a line of thinking directed toward elucidating the apoptotic profile of prostate tumour cells that may be important in determining prognosis, response to therapy and illness progression. Main consideration in this part of rewiev is given to the role of tumour suppressor genes pRb and PTEN and also the natural inhibitors of cyclin dependent kinases - proteins p21(Waf1/Cip1) and p27(Kip1). Attention is also given to the role of FAS-mediated pathways in apoptosis induction.

The mechanism of action of the tumour suppressor gene PTEN.

Intracellular levels of phosphorylation are regulated by the coordinated action of protein kinases and phosphatases. Disregulation of this balance can lead to cellular transformation. Here we review knowledge of the mechanisms of one protein phosphatase, the tumour suppressor PTEN/MMAC/TEP 1 apropos its role in tumorigenesis and signal transduction. PTEN plays an important role in the phosphatidyl-inositol-3-kinase (PI3-K) pathway by catalyzing degradation of phosphatidylinositol-(3,4,5)-triphosphate generated by PI3-K. This inhibits downstream targets mainly protein kinase B (PKB/Akt), cell survival and proliferation. PTEN contributes to cell cycle regulation by blockade of cells entering the S phase of the cell cycle, and by upregulation of p27(Kip1) which is recruited into the cyclin E/cdk2 complex. PTEN also modulates cell migration and motility by regulation of the extracellular signal-related kinase - mitogen activated protein kinase (ERK-MAPK) pathway and by dephosphorylation of focal adhesion kinase (FAK). We also emphasize the increasingly important role that PTEN has from an evolutionary point of view. A number of PTEN functions have been elucidated but more information is needed for utilization in clinical application and potential cancer therapy.