Genomic biomarkers, androgen pathway and prostate cancer

HSD3B and gene-gene interactions in a pathway-based analysis of genetic susceptibility to bladder cancer

Bladder cancer is the 4(th) most common cancer among men in the U.S. We analyzed variant genotypes hypothesized to modify major biological processes involved in bladder carcinogenesis, including hormone regulation, apoptosis, DNA repair, immune surveillance, metabolism, proliferation, and telomere maintenance. Logistic regression was used to assess the relationship between genetic variation affecting these processes and susceptibility in 563 genotyped urothelial cell carcinoma cases and 863 controls enrolled in a case-control study of incident bladder cancer conducted in New Hampshire, U.S. We evaluated gene-gene interactions using Multifactor Dimensionality Reduction (MDR) and Statistical Epistasis Network analysis. The 3'UTR flanking variant form of the hormone regulation gene HSD3B2 was associated with increased bladder cancer risk in the New Hampshire population (adjusted OR 1.85 95%CI 1.31-2.62). This finding was successfully replicated in the Texas Bladder Cancer Study with 957 controls, 497 cases (adjusted OR 3.66 95%CI 1.06-12.63). The effect of this prevalent SNP was stronger among males (OR 2.13 95%CI 1.40-3.25) than females (OR 1.56 95%CI 0.83-2.95), (SNP-gender interaction P = 0.048). We also identified a SNP-SNP interaction between T-cell activation related genes GATA3 and CD81 (interaction P = 0.0003). The fact that bladder cancer incidence is 3-4 times higher in males suggests the involvement of hormone levels. This biologic process-based analysis suggests candidate susceptibility markers and supports the theory that disrupted hormone regulation plays a role in bladder carcinogenesis.

Biomarkers for the diagnosis of new and recurrent prostate cancer

Prostate cancer is the most prevalent cancer in men and can be managed effectively if diagnosed early and monitored. Currently, prostate-specific antigen testing in conjunction with a digital rectal exam has been utilized for screening at-risk men. However, the lack of specificity of prostate-specific antigen as a marker for prostate cancer combined with the asymptomatic and slow-growing nature of prostate tumors has resulted in many men being overdiagnosed and subjected to surgery or treatment with adverse side effects. The focus in the research community currently has been on discovering noninvasive surrogate markers such as proteins, circulating tumor cells and nucleic acids in the blood or urine of patients with prostate cancer. These markers, in combination with prostate-specific antigen, are providing promise that a personalized multiparametric approach to prostate cancer diagnosis and monitoring will aid in managing this disease.

Validation of a sequential extraction and liquid chromatography-tandem mass spectrometric method for determination of dihydrotestosterone, androstanediol and androstanediol-glucuronide in prostate tissues

Androgens are key mediators of prostate development and function, a role that extends to the development of prostate diseases such as benign prostatic hyperplasia (BPH) and prostate cancer. In prostate, DHT is the major androgen and reduction and glucuronidation are the major metabolic pathways for DHT elimination. A streamlined method for quantitation of dihydrotestosterone (DHT), 5α-androstan-3α,17β-diol (3α-diol), and 3α-diol glucuronide (diol-gluc) was established and validated for use with archived prostate tissue specimens to facilitate examination of the roles of the underlying metabolism. This involved a sequential 70/30 hexane/ethyl acetate (hex/EtOAc) extraction of steroids, followed by an ethyl acetate extraction for diol-gluc. Derivatization of the hex/EtOAc fraction with2-fluoro-1-methylpyridinium p-toluene-4-sulfonate (FMP) was used to enhance sensitivity for hydroxyl steroids and liquid chromatography-tandem mass spectrometry (LC-MS/MS) was utilized for analysis of both fractions. The method was validated with calibration standards followed by recovery assessment from spiked samples of BPH and normal prostate. Lower limits of quantitation (LLOQ) were 50 pg/g, 20 pg/g and 100 pg/g for DHT, 3α-diol and diol-gluc, respectively for extracts from 50mg equivalents of tissue. Prepared samples were stable for up to three weeks at 4 °C and 37 °C. The method provides excellent sensitivity and selectivity for determination of tissue levels of DHT, 3α-diol, and diol-gluc. Furthermore, this protocol can easily be extended to other hydroxyl steroids, is relatively straightforward to perform and is an effective tool for assessing steroid levels in archived clinical prostate samples.

Biochemical polymorphism of the growth hormone system proteins and its manifestations in human prostate cells

The basic mechanisms are considered that are responsible for producing biochemical polymorphism of human proteins realized at three basic levels: the structures of genome and genes; the transcription and maturation of transcripts; the postsynthetic formation of functionally active protein products of gene expression. The data on biochemical polymorphism of growth hormone (GH) and some other proteins that are directly or indirectly necessary for its functioning and support this polymorphism by polylocus, polyallelism, alternative splicing, and various postsynthetic modifications are analyzed. The role of polymorphic proteins of the GH system is discussed in formation of a variety of oligomeric molecular structures of this system (multicomponent transport complexes, receptors, and endocellular protein ensembles involved in the regulation of gene expression). It is emphasized that such structural polymorphism significantly influences the biological effects in various parts of the GH system during physiological processes and in tumors, in particular in prostate cancer.

Molecular pathogenesis and early detection of hepatocellular carcinoma--perspectives from West Africa

This article reviews mechanisms involved in development of hepatocellular carcinoma and how host and environmental factors interact at a molecular level to cause cancer. These processes are intimately linked with strategies for early detection since molecular intermediates on the carcinogenesis pathway can now be detected with increasing levels of sensitivity. Similarly host factors influencing response to environmental agents, together with substances produced by early cancers, can be assayed in fine detail with new and emerging technologies. These advances in the field of biomarkers may lead to more rapid diagnosis and ultimately to improved survival as novel therapeutic strategies are adopted.

Translational research in hormone-related cancer

Hormones are implicated in various types of cancer, however, several aspects of steroid activity on carcinogenesis remain elusive. Recent progress has made it possible for us to directly study the biological mechanisms of disease development, including hormone-cancer relationships, from numerous viewpoints, from numerous viewpoints, including genome abnormalities. One tool is comparative genomic hybridization array (aCGH). Furthermore, it is possible to identify the so-called "cancer signature" by gene expression profiling, which provides new information about the role of steroids on carcinogenesis. DNA mutations and gene expression abnormalities may be associated with hormone-related cancer. The recent discovery of microRNA provides new opportunities for understanding the fine regulation of gene expression in cancer cells, and the role of microRNA in the relationship between hormones and cancer. From these experimental models we should be able to rapidly develop translation-to-treatment protocols. The final goal should be to design specific labs on a microchip for prognosis and therapy of individual patients. While in clinical research there is renewed attention to stratification of patients, especially those at high risk.

Intra-prostatic androgen levels during various androgen-blockade regimens

Androgens are heavily involved in the development of prostate cancer. This article reviews the scenario of the androgen environment and androgen metabolism in the prostate during androgen-deprivation therapy (ADT) in patients with prostate cancer. Ways of altering the intra-prostatic androgen milieu during various androgen-blockade regimens include surgical castration, luteinizing hormone-releasing hormone analogues to block androgen secretion by the testes, anti-androgens, and 5alpha-reductase inhibitors. The levels of androgen precursors in the blood are different under different ADT regimens, and the androgen levels in the prostate also vary according to the ADT used. This may affect the therapeutic effect of ADT. We therefore discuss the subject of prostatic androgen levels during various androgen-blockade regimens, and we describe the prospects for the future of ADT.