Polymorphisms in the gene encoding CYP1A2 influence prostate cancer risk and progression.

The role of the cytochrome P450 1A2 (CYP1A2) rs2472299, rs2470890 and rs11072508 polymorphisms in prostate cancer risk, disease progression and tumour development remains unclear. The potential associations of these three CYP1A2 polymorphisms and haplotypes with prostate cancer susceptibility and its clinicopathological characteristics were therefore investigated. The present case-control study consisted of 522 patients with prostate cancer and 554 healthy controls. High-resolution melting analysis was used to determine the CYP1A2 polymorphisms. No significant association in prostate cancer risk was seen for CYP1A2 rs2472299 and rs11072508. However, a significantly decreased risk of prostate cancer was found for CYP1A2 rs2470890 [odds ratio (OR), 0.67; P=0.02] in the recessive model. After analysis of the associations of clinical status and these three CYP1A2 polymorphisms, the CYP1A2 rs2470890 and rs11072508 polymorphisms showed a positive association with a higher Gleason score (rs2470890 OR, 1.36, P=0.04 in the allelic model; rs11072508 OR, 1.37, P=0.04 in the allelic model and OR, 1.60, P=0.03 in the dominant model). All three polymorphisms showed a significant positive association with pathological T stage in the additive, allelic and dominant genetic models (P<0.05). Haplotype analysis revealed that the most common haplotypes 'GTT' and 'ACC' were significantly associated with pathological T stages 3 and 4 (OR, 0.62; P=0.02 and OR, 1.54; P=0.03, respectively). A significant association was found between the 'GTT' haplotype and the Gleason score (OR, 0.71; P=0.03). In conclusion, these CYP1A2 polymorphisms and haplotypes have the potential to predict prostate cancer disease progression.

The driving power of the cell cycle: cyclin-dependent kinases, cyclins and their inhibitors.

The cell cycle covers cell proliferation and growth and is strictly regulated by cyclin-dependent kinase, cyclins and their inhibitors. Cyclin-dependent kinases are serine/threonine kinases that are activated in certain phases of the cell cycle by regulatory subunits, cyclins, with which they form functional heterodimeric complexes. Under physiological conditions, the activation of cyclin-dependent kinases and cyclins is strictly controlled. The formation of these complexes is inhibited, as needed, either specifically or non-specifically, by cyclin-dependent kinase inhibitors. Progression through the cell cycle is a critical process that drives many aspects of cellular function. The cell cycle is a series of events that occurs in a repeating pattern. Each cell cycle consists of two phases, interphase and mitotic phase. Their dysregulation leads to disruption of cell cycle coordination and uncontrollable cell proliferation, which is the main feature of tumorigenesis (Fig. 1, Ref. 69). Keywords: cell cycle, regulation, cyclin­dependent kinases, cyclins, inhibitors.

The ubiquitous expression of pyruvate carboxylase among human prostate tumors.

Pyruvate carboxylase (PC) is a mitochondrial enzyme catalyzing the ATP-dependent reaction of pyruvate prolongation with bicarbonate ion to oxaloacetate. The synthesis of oxaloacetate by PC, an intermediate of the Krebs cycle, is recently recognized as a significant anaplerotic reaction that supports the biosynthetic capability, growth, aggressiveness, and even viability of several cancer cell types. PC expression was confirmed in several types of cancer cells and tumors. To evaluate the possibility that prostate tumor-forming cells are also exploiting the anaplerotic role of PC, we applied immunoblotting analysis to estimate its presence. Our results revealed that PC is present among the lysate proteins derived from prostate cancer and benign prostatic hyperplasia samples. The expression of PC in cells of prostate tumors and benign prostatic hyperplasia supposes that PC could facilitate the formation of oxaloacetate in situ and enhance the autonomy of their biosynthetic metabolism from the availability of extracellular substrates by increasing the cellular anaplerotic capability (Tab. 1, Fig. 1, Ref. 30). Keywords: pyruvate carboxylase, prostate cancer, cancer metabolism, anaplerosis.

Role of Genetic Variations in CDK2, CCNE1 and p27KIP1 in Prostate Cancer.

BACKGROUND/AIM: Our aim was to investigate possible influences of genetic variants in genes involved in the G1/S transition [cyclin-dependent kinase-2 (CDK2), cyclin E1 (CCNE1) and cyclin-dependent kinase inhibitor 1B (p27KIP1)] on the expression/activity of their corresponding proteins and to assess the functional impact of these variants on the risk of prostate cancer. MATERIALS AND METHODS: We genotyped 530 cases and 562 healthy controls for two relevant single nucleotide polymorphisms (CDK2 rs2069408 and CCNE1 rs997669) by TaqMan genotyping assay. p27KIP1 rs2066827 polymorphisms were studied by polymerase chain reaction-restriction fragment length polymorphism assay. In addition, the expression of CDK2, CCNE1 and p27KIP1 was evaluated by quantitative real-time-polymerase chain reaction and western blotting in 44 prostate cancer tissues and 31 benign prostatic hyperplasia tissues. RESULTS: No association was found between CDK2 rs2069408, CCNE1 rs997669 or p27KIP1 rs2066827 polymorphisms and an increased risk of prostate cancer development. Higher CDK2 expression was more prevalent in those with rs2069408 GG genotype than in AA carriers (p>0.05). We also noted reduced p27KIP1 protein expression in those with the p27KIP1 G109 allele. No difference was observed for CCNE1 expression in relation to the risky genotype (CC). A significant association was detected between CCNE1 mRNA overexpression and development of higher-grade carcinomas (Gleason score >7, p<0.05). CONCLUSION: Polymorphisms CDK2 rs2069408, CCNE1 rs997669 and p27KIP1 rs2066827 have no significant impact on prostate cancer risk nor on the gene and protein expression of CDK2, CCNE1 and p27KIP1, although high CCNE1 expression was significantly associated with a higher tumour grade in patients with prostate cancer.

Association between estrogen receptor ß polymorphisms and prostate cancer in a Slovak population.

Sex steroid hormones have important roles in the function of the prostate; however, they may also serve as factors in the initiation and progression of carcinogenesis. Estrogens, acting through estrogen receptors, may significantly affect prostate cancer development and progression. The main aim of the present study was to analyze the association between the rs3020449, rs4986938 and rs1256049 polymorphisms in the promoter region of the estrogen receptor ß (ESR2) gene and prostate cancer risk in the Slovak population. A total of 510 patients with prostate cancer and 184 healthy men were included in the present study. No association between the rs4986938 and rs1256049 polymorphisms and prostate cancer development and progression was revealed; however, there was a statistically significant association between the rs3020449 GG genotype [odds ratio (OR), 2.35; P=0.002] and the G allele (OR, 1.42; P=0.005) and a higher risk of prostate cancer development. The rs3020449 GG genotype was significantly associated with a higher risk of development of carcinoma with a Gleason score >7 (OR, 2.66; P=0.005), as well as with the development of carcinoma with pT3/pT4 (OR, 2.28; P=0.02). According to the results from the present study, the rs3020449 polymorphism, in the promoter region of ESR2, may be considered to have a role in the development and progression of prostate cancer in the Slovak population.

Differential profiling of prostate tumors versus benign prostatic tissues by using a 2DE-MALDI-TOF-based proteomic approach.

Oncoproteomic technologies offer a complementary approach to the understanding of cancer proteins' function and the translation of molecular knowledge into clinical practice. Our aim was to compare the proteomic profiles of prostate tumors versus benign prostatic hyperplasia (BPH) tissues in order to identify modulated proteins as the potential biomarkers for prostate cancer. Proteins extracted from twenty prostate cancer tissue specimens and ten BPH tissues were analyzed by two-dimensional electrophoresis (2-DE) coupled with MALDI-TOF mass spectrometry. Western blot and quantitative real-time PCR (RT-PCR) were performed to confirm the different amounts of protein biomarkers revealed by 2DE combined with MALDI mass spectrometry. We found 42 spots whose expression in the prostate was altered more than 1.5-fold compared with BPH tissue (p<0.05). These spots represented ten different proteins that were identified by a database search after mass spectrometry: they comprised proteins involved in the regulation of actin dynamics, the cytoskeleton, and cell motility (ACTG2, ACTA2, TPM1, DES, VIM, FLNA, and TAGLN), heat shock protein-27 (Hsp27), and proteins with other functions (TR and RANBP3). Subsequent western blot and RT-PCR assays for DES, VIM, TAGLN, and Hsp27 in prostate tumor tissues and BPH tissues confirmed the observations obtained by proteomic analysis. The cytoskeletal and cytoskeleton-associated proteins identified by this approach might be useful molecular targets for prostate cancer diagnostics and may contribute to novel therapies for prostate cancer.

Association of MDM2 T309G (rs2279744) Polymorphism and Expression Changes With Risk of Prostate Cancer in the Slovak Population.

BACKGROUND/AIM: The aim of this study was to evaluate the relationship between MDM2 T309G polymorphism and prostate cancer risk in the Slovak population and the association of this polymorphism with MDM2 expression and clinicopathological features. MATERIALS AND METHODS: The MDM2 T309G polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis in 506 prostate cancer patients and 592 controls. Quantitative real-time (RT)-PCR and western blot analysis were applied to examine MDM2 expression in 47 prostate cancer tissues and 43 benign prostatic hyperplasia (BPH) tissues. RESULTS: A decreased risk of prostate cancer in men carrying the GG genotype in comparison with the TT genotype was found. A decrease in the relative MDM2 mRNA and protein levels was found in prostate cancer tissues among patients with the MDM2 GG genotype. CONCLUSION: There is a potentially protective effect of the MDM2 GG genotype on the risk of prostate cancer in the Slovak male population.

Germline Mutations in DNA Repair Genes in Patients With Metastatic Castration-resistant Prostate Cancer.

BACKGROUND/AIM: The aim of this study was to analyse the genetic profiles of metastatic castration-resistant prostate cancer (mCRPC) by using next generation sequencing to identify variants with pathogenic potential in nine DNA repair genes - BRCA1, BRCA2, RAD50, RAD51, RAD51C/D, ATM and ATR. MATERIALS AND METHODS: Isolated genomic DNA from peripheral blood of 50 patients with mCRPC was used for the sequencing of 111 genes associated with hereditary cancer on an Illumina platform. Identified variants were tested in Integrative Genomic Viewer, their clinical significance confirmed in databases and their potential impact on protein function predicted by in silico tools. RESULTS: From nine analysed DNA repair genes, we identified 14 relevant variants; three pathogenic variants - BRCA2 (rs80359306), RAD50 (rs786201531) and ATM (rs1555099760), and eleven other variants with pathogenic potential. CONCLUSION: The pathogenic variants identified in this study are located in evolutionarily conserved regions of proteins and are highly likely to affect DNA repair efficiency.