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Temozolomide (TMZ) is an alkylating agent that has become the mainstay treatment of the most malignant brain cancer, glioblastoma multiforme (GBM). Unfortunately only a limited number of patients positively respond to it. It has been shown that zinc metal reestablishes chemosensitivity but this effect has not been tested with TMZ. Using both in vitro and in vivo experimental approaches, we investigated whether addition of zinc to TMZ enhances its cytotoxicity against GBM. In vitro cell viability analysis showed that the cytotoxic activity of TMZ was substantially increased with addition of zinc and this response was accompanied by an elevation of p21, PUMA, BAX and Caspase-3 expression and a decrease in growth fraction as manifested by low ki67 and lower colony formation. Analysis of GBM as intracranial xenografts in athymic mice and administration of concurrent TMZ and zinc yielded results consistent with those of the in vitro analyses. The co-treatment resulted in significant reduction in tumor volume in TMZ/zinc treated mice relative to treatment with TMZ alone. Our results suggest that zinc may serve as a potentiator of TMZ therapy in GBM patients.

Background: Prostate cancer is highly influenced by androgens and genes. The authors investigated whether genetic polymorphisms along the androgen biosynthesis and metabolism pathways are associated with androgen concentrations or with the risk of prostate cancer or high-grade disease from finasteride treatment., Methods: A nested case-control study from the Prostate Cancer Prevention Trial using data from men who had biopsy-proven prostate cancer (cases) and a group of biopsy-negative, frequency-matched controls was conducted to investigate the association of 51 single nucleotide polymorphisms (SNPs) in 12 genes of the androgen pathway with overall (total), low-grade, and high-grade prostate cancer incidence and serum hormone concentrations., Results: There were significant associations of genetic polymorphisms in steroid 5α-reductase 1 (SRD5A1) (reference SNPs: rs3736316, rs3822430, rs1560149, rs248797, and rs472402) and SRD5A2 (rs2300700) with the risk of high-grade prostate cancer in the placebo arm of the Prostate Cancer Prevention Trial; 2 SNPs were significantly associated with an increased risk (SRD5A1 rs472402 [odds ratio, 1.70; 95% confidence interval, 1.05-2.75; Ptrend = .03] and SRD5A2 rs2300700 [odds ratio, 1.94; 95% confidence interval, 1.19-3.18; Ptrend = .01]). Eleven SNPs in SRD5A1, SRD5A2, cytochrome P450 family 1, subfamily B, polypeptide 1 (CYP1B1), and CYP3A4 were associated with modifying the mean concentrations of serum androgen and sex hormone-binding globulin; and 2 SNPs (SRD5A1 rs824811 and CYP1B1 rs10012; Ptrend < .05) consistently and significantly altered all androgen concentrations. Several SNPs (SRD5A1 rs3822430, SRD5A2 rs2300700, CYP3A43 rs800672, and CYP19 rs700519; Ptrend < .05) were significantly associated with both circulating hormone levels and prostate cancer risk., Conclusions: Germline genetic variations of androgen-related pathway genes are associated with serum androgen concentrations and the risk of prostate cancer. Further studies to examine the functional consequence of novel causal variants are warranted. Cancer 2016;122:2332-2340. © 2016 American Cancer Society., (© 2016 American Cancer Society.)

Background: Compelling and long-standing data suggest that androgens play an important role in the development of both normal prostate epithelium and prostate cancer. Although testosterone administration can induce prostate cancer (PCA) in laboratory animals, serum-based epidemiologic studies examining androgens in humans have not consistently supported a role for androgens in prostate carcinogenesis. We examined whether pre-diagnostic serum androgens were associated with PCA risk in the placebo arm of the Prostate Cancer Prevention Trial., Methods: In this nested case-control study, cases (n = 1,032) were primarily local-stage, biopsy-detected cancers, and controls (n = 1,025) were biopsy-confirmed to be PCA-free. Pre-diagnostic serum androgens (total testosterone, 3α-androstanediol glucuronide, free testosterone), estrogen-to-testosterone ratio, and sex hormone-binding globulin (SHBG) concentrations were measured in pooled (baseline and year 3) blood samples., Results: We found no significant associations between serum androgens, estrogen-to-testosterone ratios, or SHBG and risk of total, low (Gleason <7) or high-grade (Gleason 7-10) PCA., Conclusion: Much remains to be learned about the role of androgens in prostate carcinogenesis. Further research is needed to evaluate the role of androgens, timing of exposure, genetic modulators of androgen metabolism, or environmental exposures that may affect androgen influence on prostate carcinogenesis.

Background: The genetic mechanisms underlying hemangioblastoma development are still largely unknown. We used high-resolution single nucleotide polymorphism microarrays and droplet digital PCR analysis to detect copy number variations (CNVs) in total of 45 hemangioblastoma tumors., Results: We identified 94 CNVs with a median of 18 CNVs per sample. The most frequently gained regions were on chromosomes 1 (p36.32) and 7 (p11.2). These regions contain the EGFR and PRDM16 genes. Recurrent losses were located at chromosome 12 (q24.13), which includes the gene PTPN11., Conclusions: Our findings provide the first high-resolution genome-wide view of chromosomal changes in hemangioblastoma and identify 23 candidate genes: EGFR, PRDM16, PTPN11, HOXD11, HOXD13, FLT3, PTCH, FGFR1, FOXP1, GPC3, HOXC13, HOXC11, MKL1, CHEK2, IRF4, GPHN, IKZF1, RB1, HOXA9, and micro RNA, such as hsa-mir-196a-2 for hemangioblastoma pathogenesis. Furthermore, our data implicate that cell proliferation and angiogenesis promoting pathways may be involved in the molecular pathogenesis of hemangioblastoma.

This opinion piece focuses on the convergence of information technology (IT) in the form of personal monitors, especially smart phones and possibly also smart watches, individual genomic information and preventive healthcare and medicine. This may benefit each one of us not only individually but also society as a whole through iPH (individualized preventive healthcare). This shift driven by genomic and other technologies may well also change the relationship between patient and physician by empowering the former but giving him/her also much more individual responsibility.

Objective: In the Prostate Cancer Prevention Trial (PCPT), finasteride reduced the risk of prostate cancer by 25%, even though high-grade prostate cancer was more common in the finasteride group. However, it remains to be determined whether finasteride concentrations may affect prostate cancer risk. In this study, we examined the association between serum finasteride concentrations and the risk of prostate cancer in the treatment arm of the PCPT and determined factors involved in modifying drug concentrations., Methods: Data for this nested case-control study are from the PCPT. Cases were drawn from men with biopsy-proven prostate cancer and matched controls. Finasteride concentrations were measured using a liquid chromatography-mass spectrometry validated assay. The association of serum finasteride concentrations with prostate cancer risk was determined by logistic regression. We also examine whether polymorphisms in the enzyme target and metabolism genes of finasteride are related to drug concentrations using linear regression., Results and Conclusions: Among men with detectable finasteride concentrations, there was no association between finasteride concentrations and prostate cancer risk, low-grade or high-grade, when finasteride concentration was analyzed as a continuous variable or categorized by cutoff points. Since there was no concentration-dependent effect on prostate cancer, any exposure to finasteride intake may reduce prostate cancer risk. Of the twenty-seven SNPs assessed in the enzyme target and metabolism pathway, five SNPs in two genes, CYP3A4 (rs2242480; rs4646437; rs4986910), and CYP3A5 (rs15524; rs776746) were significantly associated with modifying finasteride concentrations. These results suggest that finasteride exposure may reduce prostate cancer risk and finasteride concentrations are affected by genetic variations in genes responsible for altering its metabolism pathway., Trial Registration: ClinicalTrials.gov NCT00288106.

Objective: To evaluate the effect of finasteride on serum androst-4-ene-3,17-dione (androstenedione) and its association with prostate cancer risk among subjects who participated in the Prostate Cancer Prevention Trial., Methods: We analyzed serum androstenedione levels in 317 prostate cancer cases and 353 controls, nested in the Prostate Cancer Prevention Trial, a randomized placebo-controlled trial that found finasteride decreased prostate cancer risk. Androstenedione is the second most important circulating androgen in men besides testosterone and also a substrate for 5α-reductase enzyme., Results: We observed a 22% increase in androstenedione levels compared with the baseline values in subjects who were treated with finasteride for 3 years. This significant increase did not vary by case-control status. Adjusted odds ratio and 95% confidence interval for the third tertile of absolute change in androstenedione levels compared with the first tertile were 0.42 (95% confidence interval, 0.19-0.94) for low-grade (Gleason score <7) cases. Similar results were observed when analyzed using percent change. There were no significant associations between serum androstenedione levels and the risk of high-grade disease., Conclusion: The results of this nested case-control study confirm that finasteride blocks the conversion of testosterone to dihydrotestosterone (DHT) and of androstenedione to 5α-androstanedione-3,17-dione, which also leads to the reduction of DHT formation. This decrease in DHT may help reduce the risk of low-grade prostate cancer in men. Our data on a differential effect of androstenedione also suggest that some high-grade prostate cancers may not require androgen for progression., (Copyright © 2015 Elsevier Inc. All rights reserved.)

It has been established that up to 8.3% of the biallelic coding SNPs present in dbSNP are actually artefactual polymorphism-like errors, previously termed single nucleotide differences, or SNDs. In this study, a previous analysis of SNPs in dbSNP was extended and updated to examine how the incidence of SNDs has changed over an intervening five year period. The incidence of SNDs was found to be lower than in the previous analysis at 2.2% of all biallelic SNPs. There was only a modest reduction in the percentage of SNDs in the original set of biallelic coding SNPs tested. This suggests that the overall reduction in the incidence of SNDs over the intervening 5-year period is related to an improvement in SNP detection methods and more rigorous curation, rather than efforts to ameliorate the presence of SNDs. We note that SNDs contaminating the dbSNP may lead to erroneous conclusions on human conditions., (© 2014 WILEY PERIODICALS, INC.)

Aim: Neurofibromatosis type 2 (NF2)-associated vestibular schwannomas have variable size at presentation which presents a unique challenge in NF2 patient management. Therefore, we investigated the molecular signature characteristic of the differences in size for improved individualized precise therapy., Materials & Methods: RNA expression analysis was performed on 15 small and 27 large NF2-associated vestibular schwannoma tumors using a microarray analyzing over 47,000 transcripts., Results: A signature of 11 genes was found to be correlated with NF2 tumor size., Conclusion: We have identified the genetic hallmark that differentiates large NF2-associated tumors from smaller tumors. This is the first time that these genes have been shown to be the hallmark for NF2 tumor size.

Objective: To investigate the association between the length of the polymorphic trinucleotide CAG microsatellite repeats in exon 1 of the AR gene and the risk of prostate cancer containing TMPRSS2:ETS fusion genes., Methods: This nested case-control study came from subjects enrolled in the Prostate Cancer Prevention Trial and included 195 biopsy-proven prostate cancer cases with a known TMPRSS2:ETS status and 1344 matched controls., Results: There was no association between the CAG repeat length and the risk of TMPRSS2:ETS-positive (odds ratio, 0.97; 95% confidence interval, 0.91-1.04) or TMPRSS2:ETS-negative prostate cancer (odds ratio, 1.04; 95% confidence interval, 0.97-1.11) and in patients with low- or high-grade disease., Conclusion: Our findings suggested that AR CAG repeats are not associated with TMPRSS2:ETS formation in prostate cancer., (Published by Elsevier Inc.)

Background: Schwannomas are the most common neurofibromatosis type 2 (NF2)-associated tumors with significant phenotypic heterogeneity in patients. The most severe subtype has an early and rapid progression and the mild type has a later onset and a less aggressive course. The aim of this study was to elucidate the underlying molecular differences between these groups. We compared the gene expression pattern between patients with early to late age of onset., Results: A gene signature of 21 genes was constructed to differentiate between early-onset and late-onset patients. We confirmed these results by real-time PCR for SNF1LK2, NGFRAP1L1 (BEX 5), GMNN, and EPHA2., Conclusion: Genes identified here may be additional aberrations in merlin-depleted cells that govern the disease onset. A significant number of these genes have been suggested as having a role in carcinogenesis and are used as biomarkers for prognosis in several other cancers. The role of these genes in NF2 carcinogenesis and their potential as biomarkers or drug target are worthwhile exploring.

Background: Finasteride, an inhibitor of 5α-reductase (type II), lowers intraprostatic dihydrotestosterone (DHT), which is reflected in serum as reduced 5α-androstane-3α,17β-diol glucuronide (3α-dG). It also modestly increases serum testosterone (T), estrone (E(1)), and estradiol (E(2)). In this altered hormonal milieu, it is unknown whether serum concentrations of these hormones are associated with prostate cancer risk., Methods: In this nested case-control study of men in the finasteride arm of the Prostate Cancer Prevention Trial, sex steroid hormones and sex hormone binding globulin were measured at baseline and approximately 3-year posttreatment in 553 prostate cancer cases and 694 controls., Results: Median posttreatment changes in concentrations of 3α-dG, T, E(1), and E(2) were -73.8%, +10.1%, +11.2%, and +7.5% (all P < 0.001), respectively. Neither the pre- nor posttreatment concentrations of 3α-dG, nor its change, were associated with risk. Pretreatment, high concentrations of E(1) and low concentrations of T were associated with increased cancer risk [OR; 95% confidence interval (CI) quartile 4 vs. 1: 1.38 (0.99-1.93) P(trend) = 0.03; 0.64 (0.43-0.93) P(trend) = 0.07, respectively]. Posttreatment, high concentrations of both E(1) and E(2) were associated with increased cancer risk [OR; 95% CI quartile 4 vs. 1: 1.54 (1.09-2.17) P(trend) = 0.03; 1.49 (1.07-2.07) P(trend) = 0.02, respectively]., Conclusions: Among finasteride-treated men, concentrations of 3α-dG were not associated with total or Gleason grades 2 to 6, 7 to 10, or 8 to 10 cancer. High serum estrogens may increase cancer risk when intraprostatic DHT is pharmacologically lowered., Impact: Low posttreatment serum estrogens may identify men more likely to benefit from use of finasteride to prevent prostate cancer., (2012 AACR)

DNA repair has been regarded as an important barrier to carcinogenesis. The newly discovered field of translesion synthesis (TLS) has made it apparent that mammalian cells need distinct polymerases to efficiently and accurately bypass DNA lesions. Perturbation of TLS polymerase activity by mutation, loss of expression, etc. is expected to result in the accumulation of mutations in cells exposed to specific carcinogens. Furthermore, several TLS polymerases can modulate cellular sensitivity to chemotherapeutic agents. TLS genes and TLS gene variations may thus be attractive pharmacologic and/or pharmacogenetic targets. We review herein current data with regards to the potential contribution of the primary TLS polymerase genes to cancer, their interaction with pharmacologic agents, and identify areas of interest for further research.

The etiology of prostate cancer remains elusive, although steroid hormones probably play a role. Considering the carcinogenic potential of estrogen metabolites as well as altered intraprostatic estrogen biosynthesis during the development of prostate cancer, we investigated associations between repeat polymorphisms of three key estrogen-related genes (CYP11A1, CYP19A1, UGT1A1) and risk of prostate cancer in the Prostate Cancer Prevention Trial (PCPT), designed to test finasteride versus placebo as a chemoprevention agent. Using data and specimens from 1154 cases and 1351 controls who were frequency matched on age, family history of prostate cancer and PCPT treatment arm, we used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) separately in the placebo and finasteride arms. Among men in the placebo arm, CYP19A1 7/8 genotype carriers had a significantly higher risk of prostate cancer compared with those with the 7/7 genotype (OR = 1.70, 95% CI = 1.16-2.5), regardless of Gleason grade. This genotype was also associated with elevated serum estrogen levels. For the (TA)(n) repeat polymorphism in UGT1A1, the heterozygous short (<7 repeats)/long (≥7 repeats) genotype was significantly associated with the risk of low-grade prostate cancer (OR = 1.34, 95% CI = 1.05-1.70) compared with the short/short genotype. No significant association was found with CYP11A1. These associations were not observed among men in the finasteride arm. The results indicate that repeat polymorphisms in genes involved in estrogen biosynthesis and metabolism may influence risk of prostate cancer but that their effects may be modified by factors altering hormone metabolism, such as finasteride treatment.

Objective: Finasteride reduces prostate cancer risk by blocking the conversion of testosterone to dihydrotestosterone. However, whether finasteride affects estrogens levels or change in estrogens affects prostate cancer risk is unknown., Methods: These questions were investigated in a case-control study nested within the prostate cancer prevention trial (PCPT) with 1,798 biopsy-proven prostate cancer cases and 1,798 matched controls., Results: Among men on placebo, no relationship of serum estrogens with risk of prostate cancer was found. Among those on finasteride, those in the highest quartile of baseline estrogen levels had a moderately increased risk of Gleason score < 7 prostate cancer (for estrone, odds ratio [OR] = 1.51, 95% confidence interval [CI] = 1.06-2.15; for estradiol, OR = 1.50, 95% CI = 1.03-2.18). Finasteride treatment increased serum estrogen concentrations; however, these changes were not associated with prostate cancer risk., Conclusion: Our findings confirm those from previous studies that there are no associations of serum estrogen with prostate cancer risk in untreated men. In addition, finasteride results in a modest increase in serum estrogen levels, which are not related to prostate cancer risk. Whether finasteride is less effective in men with high serum estrogens, or finasteride interacts with estrogen to increase cancer risk, is uncertain and warrants further investigation.

Enzymes encoded by the AKR1C1 and AKR1C2 genes are responsible for the metabolism of progesterone and 5α-dihydrotestosterone (DHT), respectively. The effect of amino acid substitutions, resulting from single nucleotide polymorphisms (SNPs) in the AKR1C2 gene, on the enzyme kinetics of the AKR1C2 gene product were determined experimentally by Takashi et al. In this paper, we used homology modeling to predict and analyze the structure of AKR1C1 and AKR1C2 genetic variants. The experimental reduction in enzyme activity in the AKR1C2 variants F46Y and L172Q, as determined by Takahashi et al., is predicted to be due to increased instability in cofactor binding, caused by disruptions to the hydrogen bonds between NADP and AKR1C2, resulting from the insertion of polar residues into largely non-polar environments near the site of cofactor binding. Other AKR1C2 variants were shown to involve either conservative substitutions or changes taking place on the surface of the molecule and distant from the active site, confirming the experimental finding of Takahashi et al. that these variants do not result in any statistically significant reduction in enzyme activity. The AKR1C1 R258C variant is predicted to have no effect on enzyme activity for similar reasons. Thus, we provide further insight into the molecular mechanism of the enzyme kinetics of these proteins. Our data also highlight previously reported difficulties with online databases.

Purpose: We investigated the association between the length of the polymorphic trinucleotide CAG microsatellite repeats in exon 1 of the AR gene and the risk of prostate cancer., Materials and Methods: This is a nested case-control study of 1,159 cases and 1,353 controls from the Prostate Cancer Prevention Trial, a randomized, placebo controlled trial testing whether the 5α-reductase inhibitor finasteride could decrease the 7-year prevalence of prostate cancer. During the course of the trial men underwent annual digital rectal examination and prostate specific antigen measurement. Prostate biopsy was recommended in all men with abnormal digital rectal examination or finasteride adjusted prostate specific antigen greater than 4.0 ng/ml. Cases were drawn from men with biopsy determined prostate cancer identified by for cause or end of study biopsy. Controls were selected from men who completed the end of study biopsy., Results: Mean CAG repeat length did not differ between cases and controls. The frequency distribution of cases and controls for the AR CAG repeat length was similar. There were no significant associations of CAG repeat length with prostate cancer risk when stratified by treatment arm (finasteride or placebo), or when combined. There was also no significant association between CAG repeat length and the risk of low or high grade prostate cancer., Conclusions: There is no association of AR CAG repeat length with prostate cancer risk. Knowledge of AR CAG repeat length provides no clinically useful information to predict prostate cancer risk., (Copyright © 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Large clinical trials provide a tremendous opportunity to integrate correlative, comprehensive biological studies with invaluable repositories of biospecimens and clinical and other data from the trial. The Prostate Cancer Prevention Trial (PCPT) was a phase III randomized, double-blind, placebo-controlled clinical trial of finasteride in 18,882 men. Clinical data and blood and tissue specimens were collected at baseline and throughout the study, offering an opportunity to create a program project to investigate hypotheses related to the biology underlying the PCPT findings as well as the etiology and risk of prostate cancer. The transition of the randomized PCPT into this translational and epidemiologic scientific investigation required extensive planning and coordination. Five individual but interrelated projects were brought together with the underlying program theme of the genetic, metabolic, and environmental factors associated with the risks of overall and high-grade prostate cancer and how these factors affected the efficacy of finasteride in preventing cancer. All projects with serum-based measures use a single, shared, nested case-control sample of participants so that each subject provides a more complete biomarker and genetic profile for the evaluation of joint effects of these factors. Strengths of this program include the following: 1) the control group contains only men who are negative for biopsy-detected cancer, 2) the statistical methods to evaluate associations of risk factors with disease are shared across all projects, 3) the large number of cancer cases with fully characterized genetic, metabolic, and behavioral exposures, 4) a central pathology core histopathologically classified the prostate cancer, and 5) cancer cases identified during the PCPT reflect the characteristics of cases currently being detected in the prostate-specific antigen screening era, leading to contemporary and highly relevant results. This article describes the comprehensive methodology and multidisciplinary collaborations, both national and international, essential to a major risk-modeling research program. We provide a framework for doing collaborative research in an international setting structured around a common theme of a clinical trial., (©2010 AACR.)

Incidences of prostate cancer in most countries are increasing owing to better detection methods; however, prevention with the use of finasteride, a very effective steroid 5α-reductase type II inhibitor, has been met with mixed success. A wide interindividual variation in response exists and is thought to be due to heritable factors. This article summarizes the literature that attempts to elucidate the molecular mechanisms of finasteride in terms of its metabolism, excretion and interaction with endogenous steroid molecules. We describe previously reported genetic variations of steroid-metabolizing genes and their potential association with finasteride efficacy. Based on the literature, we outline directions of research that may contribute to understanding the interindividual variation in finasteride prevention and to the future development of personalized medicine.

The biological role of steroid 5alpha-reductase isozymes (encoded by the SRD5A1 and SRD5A2 genes) and angiogenic factors that play important roles in the pathogenesis and vascularization of prostate cancer (PC) is poorly understood. The sub-cellular expression of these isozymes and vascular endothelial growth factor (VEGF) in PC tissue microarrays (n=62) was examined using immunohistochemistry. The effect of SRD5A inhibition on the angiogenesis pathway genes in PC was also examined in prostate cell lines, LNCaP, PC3, and RWPE-1, by treating them with the SRD5A inhibitors finasteride and dutasteride, followed by western blot, quantitative PCR, and ELISA chip array techniques. In PC tissues, nuclear SRD5A1 expression was strongly associated with higher cancer Gleason scores (P=0.02), higher cancer stage (P=0.01), and higher serum prostate specific antigen (PSA) levels (P=0.01), whereas nuclear SRD5A2 expression was correlated with VEGF expression (P=0.01). Prostate tumor cell viability was significantly reduced in dutasteride-treated PC3 and RWPE-1 cells compared with finasteride-treated groups. Expression of the angiogenesis pathway genes transforming growth factor beta 1 (TGFB1), endothelin (EDN1), TGFalpha (TGFA), and VEGFR1 was upregulated in LNCaP cells, and at least 7 out of 21 genes were upregulated in PC3 cells treated with finasteride (25 muM). Our findings suggest that SRD5A1 expression predominates in advanced PC, and that inhibition of SRD5A1 and SRD5A2 together was more effective in reducing cell numbers than inhibition of SRD5A2 alone. However, these inhibitors did not show any significant difference in prostate cell angiogenic response. Interestingly, some angiogenic genes remained activated after treatment, possibly due to the duration of treatment and tumor resistance to inhibitors.

Classical or transferase-deficient galactosaemia is an inherited metabolic disorder caused by mutation in the human Galactose-1-phosphate uridyl transferase (GALT) gene. Of some 170 causative mutations reported, fewer than 10% are observed in more than one geographic region or ethnic group. To better understand the population history of the common GALT mutations, we have established a haplotyping system for the GALT locus incorporating eight single nucleotide polymorphisms and three short tandem repeat markers. We analysed haplotypes associated with the three most frequent GALT gene mutations, Q188R, K285N and Duarte-2 (D2), and estimated their age. Haplotype diversity, in conjunction with measures of genetic diversity and of linkage disequilibrium, indicated that Q188R and K285N are European mutations. The Q188R mutation arose in central Europe within the last 20 000 years, with its observed east-west cline of increasing relative allele frequency possibly being due to population expansion during the re-colonization of Europe by Homo sapiens in the Mesolithic age. K285N was found to be a younger mutation that originated in Eastern Europe and is probably more geographically restricted as it arose after all major European population expansions. The D2 variant was found to be an ancient mutation that originated before the expansion of Homo sapiens out of Africa.

The creation of single nucleotide polymorphism (SNP) databases (such as NCBI dbSNP) has facilitated scientific research in many fields. SNP discovery and detection has improved to the extent that there are over 17 million human reference (rs) SNPs reported to date (Build 129 of dbSNP). SNP databases are unfortunately not always complete and/or accurate. In fact, half of the reported SNPs are still only candidate SNPs and are not validated in a population. We describe the identification of SNDs (single nucleotide differences) in humans, that may contaminate the dbSNP database. These SNDs, reported as real SNPs in the database, do not exist as such, but are merely artifacts due to the presence of a paralogue (highly similar duplicated) sequence in the genome. Using sequencing we showed how SNDs could originate in two paralogous genes and evaluated samples from a population of 100 individuals for the presence/absence of SNPs. Moreover, using bioinformatics, we predicted as many as 8.32% of the biallelic, coding SNPs in the dbSNP database to be SNDs. Our identification of SNDs in the database will allow researchers to not only select truly informative SNPs for association studies, but also aid in determining accurate SNP genotypes and haplotypes.

Most studies of tumor instability are PCR-based. PCR-based methods may underestimate mutation frequencies of heterogeneous tumor genomes. Using a novel PCR-free random cloning/sequencing method, we analyzed 100 kb of total genomic DNA from blood lymphocytes, normal prostate and tumor prostate taken from six individuals. Variations were identified by comparison of the sequence of the cloned fragments with the nr-database in Genbank. After excluding known polymorphisms (by comparison to the NCBI dbSNP), we report a significant over-representation of variants in the tumors: 0.66 variations per kilobase of sequence, compared with the corresponding normal prostates (0.14 variations/kb) or blood (0.09 variations/kb). Extrapolating the observed difference between tumor and normal prostate DNA, we estimate 1.8 million somatic (de novo) alterations per tumor cell genome, a much higher frequency than previous measurements obtained by mostly PCR-based methods in other tumor types. Moreover, unlike the normal prostate and blood, most of the tumor variations occur in a specific motif (P = 0.046), suggesting common etiology. We further report high tumor cell-to-cell heterogeneity. These data have important implications for selecting appropriate technologies for cancer genome projects as well as for understanding prostate cancer progression.

Somatic mutations are hallmarks of cancer progression. We sequenced 26 matched human prostate tumor and constitutional DNA samples for somatic alterations in the SRD5A2, HPRT, and HSD3B2 genes, and identified 71 nucleotide substitutions. Of these substitutions, 79% (56/71) occur within a WKVnRRRnVWK sequence (a novel motif we call THEMIS [from the ancient Greek goddess of prophecy]: W=A/T, K=G/T, V=G/A/C, R=purine (A/G), and n=any nucleotide), with one mismatch allowed. Literature searches identified this motif with one mismatch allowed in 66% (37/56) of the somatic prostate cancer mutations and in 74% (90/122) of the somatic breast cancer mutations found in all human genes analyzed. We also found the THEMIS motif with one allowed mismatch in 88% (23/26) of the ras1 gene somatic mutations formed in the sensitive to skin carcinogenesis (SENCAR) mouse model, after induction of error-prone DNA repair following mutagenic treatment. The high prevalence of the motif in each of the above mentioned cases cannot be explained by chance (P<0.046). We further identified 27 somatic mutations in the error-prone DNA polymerase genes pol eta, pol kappa, and pol beta in these prostate cancer patients. The data suggest that most somatic nucleotide substitutions in human cancer may occur in sites that conform to the THEMIS motif. These mutations may be caused by "mutator" mutations in error-prone DNA polymerase genes., (Copyright 2008 Wiley-Liss, Inc.)

The steroid 5-alpha reductase type II gene (SRD5A2) encodes the enzyme which converts testosterone (T) to the more active androgen dihydrotestosterone. A non-synonymous single-nucleotide polymorphism, A49T (rs9282858), in SRD5A2 has been implicated in prostate cancer risk; however, results have been inconsistent. In 1999, we reported a strong association between the A49T variant and prostate cancer risk among African-Americans and Latinos in the Hawaii-Los Angeles Multiethnic Cohort (MEC). We report here an updated analysis of MEC data including the five major ethnic groups of the MEC, an increased sample size, improved genotyping technology and a comprehensive meta-analysis of the published literature. We found a non-statistically significant positive association between prostate cancer risk and carrying either the AT or TT genotype [odds ratio (OR) = 1.16, 95% confidence interval (CI) 0.79-1.69] in the MEC. This finding is in contrast to our previous results of ORs of 3.28 and 2.50 for the association between prostate cancer risk and the variant in African-American and Latino men, respectively; this can be accounted for by genotyping error in our earlier study. Meta-analysis of the published literature, including the current MEC data, shows a summary OR of 1.13 (95% CI 0.95-1.34) for the A49T variant with prostate cancer risk among sporadic, unselected cases. After evaluating more than 6000 cases and 6000 controls, there is little evidence of a role for the SRD5A2 A49T variant in prostate cancer risk. Overall, this report highlights the importance of rigorous genotyping quality control measures and replication efforts in genetic association studies.

The pharmacogenetics of cancer treatment has been aimed at identifying genetic components of interindividual variability in patients' response to cancer chemotherapy and toxicity. This, in turn, will establish an individually based treatment, and also elucidate the molecular basis of the treatment regimen for further improvements. Brain cancer is an instructive example for the potential contributions of pharmacogenomics to improved treatment in the 21st century. Patients with oligodendrogliomas have benefited from phamacogenomics, as there is a clear relationship between response to chemotherapy and chromosomal profile. Drug efficacy, safety and response could be improved by using pharmacogenomics to identify genetic markers that differentiate responder from nonresponder patient groups, as well as identifying patients likely to develop adverse drug reactions. This review will focus on how pharmacogenomics by microarray studies may lead to much more accurate tumor classification, drug and biomarker discovery, and drug efficacy testing. We will discuss relevant scientific advances in pharmacogenetics for more personalized chemotherapy.

Purpose of Review: Despite clinical and experimental evidence that show androgens are important in prostate carcinogenesis, epidemiologic studies of serum androgens have been inconclusive. In this review, we summarize the current state of the literature and provide insights and direction for epidemiologic research on androgens and prostate cancer., Recent Findings: To date, data on serum androgens in prostate cancer remain inconclusive. Large studies on variants in some androgen-metabolizing genes [SRD5A2, CYP17A1, and hydroxysteroid dehydrogenase (HSD)17B1] do not show a convincing links to prostate cancer, though there are insufficient data to draw conclusions on other genes related to androgen metabolism, including UDP-glycosyltransferases (UGT), sulfotransferases (SULT), CYP3A, and estrogen-related genes. There is some evidence, although controversial, suggesting that select variants may confer risk to certain subtypes of prostate cancer. The most notable finding in 2007 is the highly reproducible link between the chromosome 8q24 risk region and prostate cancer susceptibility., Summary: Besides the link between the 8q24 region and prostate cancer risk, population studies do not convincingly show that polymorphisms in androgen metabolism genes are associated with prostate cancer risk. Large epidemiologic studies with comprehensive gene coverage and reliable exposure data are needed to clarify further the role of androgens and their related genes in prostate cancer.

Prostate cancer is the most frequent male malignancy diagnosed in western countries and the second leading cause of cancer-related deaths. The growth and function of the prostate gland depends on androgens. Owing to the importance of androgens in prostate development, genes involved in androgen biosynthesis and metabolism have been extensively studied. In this review, we address recent progress toward the use of inherited and acquired genetic variants to predict susceptibility and clinical outcomes of prostate cancer patients. Many of these genetic variants involve several genes related to the biosynthesis and metabolism of androgens, such as steroid-5-alpha-reductase, alpha polypeptide 2 (SRD5A2), cytochrome P450 (CYP)19A1, CYP17A1, hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 2 (HSD3B2) and androgen receptor (AR). With increasing knowledge, it may be possible to distinguish indolent from aggressive prostate tumors by molecular fingerprinting. Furthermore, with the emergence of new investigative tools, such as microarray platforms and comparative genomic hybridization (CGH) array, a variety of new genomic biomarkers will be available in the future to provide accurate prognostic and monitoring solutions for individualized patient care.

Prostate cancer is the most common non-skin cancer and the second leading cause of cancer deaths among men in most Western countries. Despite its high morbidity and mortality, the etiology of prostate cancer remains obscure. Although compelling laboratory data suggest a role for androgens in prostate carcinogenesis, most epidemiologic data, including serological and genetic studies, are inconclusive. In this chapter, we review the status of serologic studies and discuss the importance of intra-prostatic hormone levels in possibly clarifying the often-contradictory data on serologic studies. To provide insights and directions for epidemiologic research on hormones and prostate cancer, this review centers on the molecular epidemiology of hormone-related genetic loci. These loci have been investigated in a number of studies to date and will undoubtedly expand even further as rich new genetic information sources and high-throughput genotyping and analysis methods become available. Due to the enormous number of these loci, we recommend careful analysis and cautious interpretation of studies of genetic markers, including microsatellites and single nucleotide polymorphisms (SNPs), as false positive and negative results are likely due to limited statistical power, multiple hypothesis testing, population stratification, or non-representative population sampling. This review also highlights the need for replication in various populations, as well as reasons for performing functional analyses of SNPs, a critical and often under-appreciated component of molecular epidemiologic investigations. The time is ripe for concerted, large-scale multidisciplinary investigations that incorporate molecular genetics, biochemistry, histopathology, and endocrinology into traditional epidemiologic studies. Such collaboration will lead to a deeper understanding of the etiologic pathways of prostate cancer, ultimately yielding better preventive, diagnostic, and therapeutic strategies.

PTEN is an important tumor-suppressor gene associated with many cancers. Through expression profiling of glioblastoma tissue samples and prostate cancer xenografts, we identified a molecular signature for loss of the PTEN tumor suppressor in glioblastoma and prostate tumors. The PTEN signature consists of a minimum of nine genes, several of which are involved in various pathways already implicated in tumor formation. Among these signature genes, the most significant was an increase in insulin growth factor-binding protein 2 (IGFBP-2) mRNA. Up-regulation of IGFBP-2 was confirmed at the protein level by Western blot analysis and validated in samples not included in the microarray analysis. The link between IGFBP-2 and PTEN was of particular interest because elevated serum IGFBP-2 levels have been reported in patients with prostate and brain tumors. To further investigate this link, we determined that IGFBP-2 expression is negatively regulated by PTEN and positively regulated by phosphatidylinositol 3-kinase (PI3K) and Akt activation. In addition, Akt-driven transformation is impaired in IGFBP2(-/-) mouse embryo fibroblasts, implicating a functional role for IGFBP-2 in PTEN signaling. Collectively, these studies establish that PTEN and IGFBP-2 expression are inversely correlated in human brain and prostate cancers and implicate serum IGFBP-2 levels as a potential serum biomarker of PTEN status and PI3K Akt pathway activation in cancer patients.

Genomic approaches to cancer are beginning to have an important impact in unraveling the complex etiologies of this disease, as well as allowing us to rationally treat afflicted patients. In this article, we will focus largely on genomic approaches to breast and prostate cancer susceptibility, as well as pharmacogenomic approaches to treatment. Current genomic approaches to cancer susceptibility have led to some significant, if not spectacular, successes which include breast cancer. More modest achievements, if not outright failures, such as in prostate cancer, are also notable and will be discussed further. We propose interdisciplinary approaches involving basic, clinical and population scientists to vigorously attack the cancer problem scientifically and with more organization. We highlight recent successes and suggest new approaches with a personal, if not provocative, perspective.

Significant evidence implicates androgens in prostate cancer etiology. We review recent data with regard to the association between several allelic variants of specific androgen-metabolic genes and the predisposition to prostate cancer. We also review the emerging evidence regarding the role of genetic variants of these genes as well as the androgen receptor in prostate cancer progression. Based on the prostate cancer paradigm, we propose that a multidisciplinary attack on the problem--involving biochemistry, genetics, pharmacogenetics, endocrinology and molecular epidemiology--may be important for the understanding and successful treatment of complex (in terms of etiology) human diseases.

The prostate gland is an androgen-dependent, and polymorphisms in androgen synthesis gene steroid 5-alpha reductase type II (SRD5A2) may be associated with benign prostatic hyperplasia (BPH) and prostate cancer. We evaluated the association between 3 polymorphisms in the SRD5A2 gene (2 single nucleotide polymorphism: alanine-49 to threonine [A49T] and valine-89 to leucine [V89L], and a (TA)n dinucleotide repeat in the 3' untranslated region), and BPH and prostate cancer within a multiethnic population. Men between 60 and 86 years of age were recruited from annual prostate cancer screening programs and from a large urology clinic. Unconditional logistic regression was used to compute odds ratios (OR) and 95% confidence intervals (95% CI). We genotyped 606 men (412 Hispanic, 98 Caucasian, 73 African-American, and 23 Asian), of whom 100 had prostate cancer, 393 had BPH (280 symptomatic and 113 asymptomatic), and 113 had normal prostates. Overall, the V89L variant was associated with prostate cancer; the OR for men with the leucine-leucine (LL) genotype compared to men with the valine-valine (VV) genotype was 4.47 (95% CI, 1.24-16.18). This association was stronger in Hispanics (OR=7.26; 95% CI: 1.49-35.47). Although V89L was nonsignificantly associated with BPH in overall population, BPH risk increased significantly with the number of L alleles in Hispanics (P for trend=0.03). Prostate cancer and BPH were not associated with the alanine-49 to threonine single nucleotide polymorphism and the (TA)n repeat. These results suggest that the SRD5A2 gene may play an important role in both BPH and prostate cancer.

Human steroid 5 alpha-reductase type II is a prostate-specific, membrane-associated enzyme that catalyzes the conversion of testosterone to dihydrotestosterone, the most potent androgen in the prostate gland. Genetic variants of this enzyme have been associated with both the development and the progression of prostate cancer. Both finasteride and dutasteride are competitive inhibitors of the type II steroid 5 alpha-reductase that have been effectively used for the treatment of benign prostatic hyperplasia. Finasteride has also been successfully utilized for prostate cancer chemoprevention. We here investigate 5 alpha-reductase inhibition assays in vitro to measure the effect of incubation time on the apparent inhibition constant (Ki) for both constitutional and somatic (prostate cancer) enzyme variants. Our systematic pharmacogenetic analysis shows that both finasteride and dutasteride are slow, time-dependent inhibitors of steroid 5 alpha-reductase type II, and that the inhibition kinetics depend on the 5 alpha-reductase genotype. We also show that, overall, dutasteride is a more efficient steroid 5 alpha-reductase inhibitor than finasteride. Based on our data, we are able to map areas of the enzyme that are responsible for this time-dependent inhibition for either (or both) enzyme inhibitor(s). This comprehensive pharmacogenetic analysis of steroid 5 alpha-reductase variants unveiled significant pharmacogenetic variation for both finasteride and dutasteride and thus should be taken into account when designing protocols for treatment and/or chemoprevention of prostatic diseases with either one of these 5 alpha-reductase inhibitors since there is considerable pharmacogenetic variation for both drugs.

One of the most promising applications of microarrays is class distinction through gene expression profiling as a diagnostic tool. However, as there is apparent spatial heterogeneity in the morphology of cancer cells within a tumor, it is unclear if tumor sampling can be applied and yield consistent signals. In this report, we examined six brain tumors, four glioblastoma, and two oligodendroglioma biopsies. The six brain tumor tissues from two distinct different classes were dissected in four distinct areas and gene expression was profiled using microarrays. We used hierarchical clustering to compare the variability of gene expression profiles between spatially distinct biopsies of the same tumor as compared to the variability between tumors of the same histologic group. We conclude that, in general, repeat spatially distinct samples are not needed for microarray experiments and the gene expression signatures are robust across the tumor. Predominantly, variation was much greater between samples from different patients than from the multiple samplings of given tumor. Further, we compared biopsy expression profiles to the cell lines derived from those tissues. In general, the tumor cell lines vary greatly from the parental tissues and cluster more strongly with each other than the parental tissue. We select and examine the set of genes altered in expression to allow adaptation to cell culture.

Prostate cancer is a very common disease in industrialized countries and it is known to be androgen-dependent. The human SRD5A2 gene encodes the prostatic (or type II) steroid 5alpha-reductase, which catalyses the irreversible conversion of testosterone to dihydrotestosterone (DHT), the most active androgen in the prostate. We have sequenced the entire protein-coding region of this locus in 30 microdissected prostate adenocarcinomas. We identified a total of 17 de novo amino-acid substitutions in 13 of these tumors. We also identified six additional silent substitutions. In total, 18 out of 30 (60%) of the tumors examined had de novo somatic substitutions in the prostatic steroid 5alpha-reductase-coding region. We also characterized all of the SRD5A2 missense substitutions biochemically and pharmacologically, using three 5alpha-reductase inhibitors, including finasteride. The biochemical parameters of the distinct 5alpha-reductase missense substitutions varied substantially. We note that two out of the three recurrent SRD5A2 missense substitutions increased 5alpha-reductase in vitro activity, while the third one is essentially neutral. These findings are consistent with a role for increased DHT levels in the prostate through increased activity of the SRD5A2 locus in prostate cancer progression, in a subset of patients. Our pharmacologic studies also reveal substantial variability for each 5alpha-reductase inhibitor. These data, therefore, should be taken into account in both prevention as well as therapeutic trials of prostate cancer utilizing 5alpha-reductase inhibitors.

We have made remarkable progress in understanding the molecular bases of many Mendelian diseases over the past 2-3 decades. The current interest in discovering the molecular basis of complex diseases uses either linkage or candidate gene approaches. The latter often uses case/control (or case/cohort) study designs. We believe it is critically important to have a thorough understanding of SNP (single nucleotide) and haplotype function in such endeavors. Functionally neutral SNPs and haplotypes are probably best suited for linkage studies (far away from the locus of interest). Functionally relevant SNPs and haplotypes seem best suited for candidate gene approaches. The need for functional data may result in a renaissance of biochemical genetics with a new twist in the genomic era. We propose that the functional characterization of SNPs and haplotypes be advanced with great vigor for those genes with defined assayable phenotypes. These systematic investigations will involve classical biochemistry, modern genetics, and genomics and will probably also draw on newer technologies such as microarrays. In short, a renaissance of biochemical genetics will advance our understanding of complex diseases.

Prostate cancer is the most common non-skin cancer in the US; it is the second leading cause of death from cancer among US men, and the seventh leading cause of death in the US. This review examines the recent biochemical and pharmacogenetic literature related to prostate cancer, specifically that which focused on constitutional ('germline') single nucleotide polymorphisms at 'functional candidate' genes for prostate cancer. The investigations summarized in this review demonstrate the need to study the molecular genetics at these loci to rationally develop personalized medicine. In addition, the identification of somatic pharmacogenetic alterations in one of these loci suggests that this may also be a fruitful field of investigations with important clinical applications. Pharmacogenomic investigations of constitutional and tumor DNA may lead to significant advances in chemoprevention, presymptomatic diagnosis and improved treatment of prostate cancer.

Purpose: We review recent molecular epidemiological data with regard to the association between several allelic variants of certain androgen-metabolic genes and the predisposition to and progression of prostate cancer., Materials and Methods: We review recent data dealing with genetic variations in androgens and the etiology of prostate cancer., Results: Recent molecular epidemiological data support an association between several allelic variants of certain androgen-metabolic genes and the predisposition to and progression of prostate cancer. While some of the allelic variants examined are consistently shown to be associated with increased prostate cancer risk, most of the variants show significant variability in risk., Conclusions: A multidisciplinary attack on this problem, involving biochemistry, molecular genetics, pharmacogenetics, endocrinology and epidemiology, may be a useful paradigm in the analysis of prostate cancer and other complex human diseases. Based on the reviewed literature, we propose a guide on how and which single nucleotide polymorphisms to use in linkage and association studies of multifactorial phenotypes.

Deficiency of citrin encoded by SLC25A13 causes adult-onset type II citrullinemia (CTLN2) and idiopathic neonatal hepatitis (NICCD). So far we have diagnosed 126 (3) CTLN2 and 103 (4) NICCD patients in Japan (and other countries). From preliminary population analysis of the known nine SLC25A13 mutations, we found that the carrier frequency is high in China (1/79), Taiwan (1/98), and Korea (1/50) as well as Japan (1/69), suggesting that many patients with citrin deficiency exist in East Asia.

Androgens are essential for the growth of the prostate gland and have been implicated in the development of prostate cancer. Little is known about the determinants of androgen levels in men, although observed ethnic differences suggest they may have a genetic basis. Several polymorphisms have been identified in the steroid 5 alpha-reductase type II gene (SRD5A2), which encodes an enzyme that catalyzes the conversion of testosterone to its more potent metabolite, dihydrotestosterone. Although some of these polymorphisms have been associated with increased prostate cancer risk, the association with circulating androgen levels remains unclear. The purpose of this study is to investigate the association between the (TA)(n) dinucleotide repeat polymorphism in the 3' untranslated region and the A49T polymorphism (which replaces the normal alanine with threonine at codon 49) in the SRD5A2 gene and serum androgen concentrations in 604 British men. In particular, we wanted to test the hypotheses that the variant alleles are associated with an increased serum concentration of androstanediol glucuronide, a direct metabolite of dihydrotestosterone and a serum marker of 5 alpha-reductase activity. Mean hormone concentrations were evaluated in each genotype, and adjusted for age and other relevant factors. We found no evidence that the SRD5A2 (TA)(n) repeat polymorphism was associated with androgen levels. Men who possessed one or two copies of the variant T allele in the A49T polymorphism had a significantly 24% lower androstanediol glucuronide concentration than men who were homozygous for the wild-type allele (P = 0.0003). Because of the rarity of this variant allele, larger studies are needed to additionally clarify the role of the A49T polymorphism in androgen metabolism.

Deficiency in the galactose-1-phosphate uridyltransferase (GALT) enzyme results in accumulation of galactose and its metabolites in the ovary (Am J Epidemiol 1989;130:904-10). Galactose may raise gonadotropin levels, resulting in proliferation of ovarian epithelium. In 1993-1999, the authors conducted a population-based case-control study of ovarian cancer in Hawaii and Los Angeles, California, to examine the hypothesis that reduced GALT activity is associated with an increased risk of ovarian cancer. A total of 239 ovarian cancer cases and 244 population controls were interviewed. A blood sample was collected to measure levels of GALT and to assay for the N314D (A940G) polymorphism of the GALT gene. Covariate-adjusted mean GALT activity was similar between cases (23.8 micro mol per hour/g hemoglobin (Hb)) and controls (23.7 micro mol per hour/g Hb) (p = 0.83). No evidence was found for a dose-response relation between the odds ratios for ovarian cancer and GALT activity or the ratio of lactose intake to GALT activity. The risk associated with the presence of at least one variant Asp314 allele was 0.77 (95% confidence interval: 0.42, 1.41). This study did not support the hypothesis that reduced galactose metabolism is a risk factor for ovarian cancer, although increased GALT activity attenuated the inverse association of oral contraceptive pill use with risk.