Avelino Fraga

Genetic Polymorphism in EGF Is Associated with Prostate Cancer Aggressiveness and Progression-Free Interval in Androgen Blockade–Treated Patients

Purpose: Most prostate cancer patients develop resistance to androgen deprivation treatment, resulting in hormone resistance. Epidermal growth factor (EGF) activates several pro-oncogenic intracellular pathways inducing proliferation, differentiation, and tumorigenesis in epithelial cells. The EGF-EGF receptor pathway seems to be especially relevant in hormone-resistant prostate cancer stage. A single nucleotide polymorphism G>A in +61 locus of EGF gene has been described, in which A homozygous carriers express significantly less EGF protein compared with G allele carriers. Our purpose was to investigate the potential prognostic and predictive role of EGF functional genetic variant +61 G>A in prostate cancer patients submitted to androgen blockade therapy (ABT). Experimental Design: We conducted a case-control study in prostate cancer patients treated with ABT (n = 123) and in healthy controls without evidence of cancer (n = 152). Cumulatively, a follow-up study (median follow-up, 37 months) was undertaken to evaluate response to ABT therapy in prostate cancer patients. EGF +61 G>A genotypes were detected by PCR-RFLP. Results: We found increased risk in G carriers, after age-adjusted regression analysis, for being diagnosed with Gleason ≥7 and with metastatic disease compared with control group (CG; age-adjusted odds ratio, 3.37, P = 0.004 and age-adjusted odds ratio, 2.61, P = 0.043, respectively). Kaplan-Meier survival analysis and log-rank test showed an influence of EGF +61 G>A polymorphism in time to relapse during ABT (P = 0.018). Conclusions:EGF functional polymorphism may contribute to earlier relapse in ABT patients, supporting the involvement of EGF as an alternative pathway in hormone-resistant prostatic tumors. Furthermore, our results lend support to EGF-EGF receptor pathway as an additional therapeutic target during hormonal treatment.

Hypoxia and Prostate Cancer Aggressiveness: A Tale With Many Endings

Angiogenesis, increased glycolysis, and cellular adaptation to hypoxic microenvironment are characteristic of solid tumors, including prostate cancer. These representative features are the cornerstone of cancer biology, which are well correlated with invasion, metastasis, and lethality, as well as likely with the success of prostate cancer treatment (eg, tumor hypoxia has been associated with resistance to chemotherapy and radiotherapy). It is well established that prostate cancer cells also metabolically depend on enhanced glucose transport and glycolysis for expansion, whereas growth is contingent with neovascularization to permit diffusion of oxygen and glucose. While hypoxia inducible factor 1 alpha (HIF-1α) remains the central player, the succeeding activated molecules and pathways track distinct branches, all positively correlated with the degree of intratumoral hypoxia. Among these, the vascular endothelial growth factor axis as well as the lysyl oxidase and carbonic anhydrase IX activities are notable in prostate cancer and merit further study. Here, we demonstrate their linkage with HIF-1α as a tentative explanatory mechanism of prostate cancer aggressiveness. Hypoxia drives a tale where HIF-1α-dependent effects lead to many influences in distinct key cancer biology features, rendering targeted therapies toward targets at the endings less efficient. The most appropriate approach will be to inhibit the upstream common driver (HIF-1α) activity. Additional translational and clinical research initiatives in prostate cancer are required to prove its usefulness.

Tumor Cell-educated Periprostatic Adipose Tissue Acquires an Aggressive Cancer-promoting Secretory Profile

Background/Aims: The microenvironment produces important factors that are crucial to prostate cancer (PCa) progression. However, the extent to which the cancer cells stimulate periprostatic adipose tissue (PPAT) to produce these proteins is largely unknown. Our purpose was to determine whether PCa cell-derived factors influence PPAT metabolic activity. Methods: Primary cultures of human PPAT samples from PCa patients (adipose tissue organotypic explants and primary stromal vascular fraction, SVF) were stimulated with conditioned medium (CM) collected from prostate carcinoma (PC3) cells. Cultures without CM were used as control. We used multiplex analysis and ELISA for protein quantification, qPCR to determine mitochondrial DNA (mtDNA) copy number and zymography for matrix metalloproteinase activity, in order to evaluate the response of adipose tissue explants and SVFs to PC3 CM. Results: Stimulation of PPAT explants with PCa PC3 CM induced adipokines associated with cancer progression (osteopontin, tumoral necrosis factor alpha and interleukin-6) and reduced the expression of the protective adipokine adiponectin. Notably, osteopontin protein expression was 13-fold upregulated. Matrix metalloproteinase 9 activity and mitochondrial DNA copy number were higher after stimulation with cancer CM. Stromovascular cells from PPAT in culture were not influenced by tumor-derived factors. Conclusion: The modulation of adipokine expression by tumor CM indicates the pervasive extent to which tumor cells command PPAT to produce factors favorable to their aggressiveness.

Hipoxia tumoral: Papel del factor inducible por hipoxia

HIF Hipoxia Cancer Los tumores solidos, por lo general, existen y progresan en un ambiente de hipoxia; asi se observa que las celulas tumorales son resistentes a la apoptosis y se acompanan de un aumento de la angiogenesis, volviendose mas agresivas, con capacidad invasora y resistentes al tratamiento. La genetica y los mecanismos biologicos subyacentes a este fenomeno son todavia poco claros, pero muchos estudios sugieren un papel del factor inducible por hipoxia (hipoxia inducible factor [HIF]) en este proceso. En condiciones de hipoxia, la subunidad alfa no es destruida y activara la transcripcion de un conjunto de genes que contribuyen a la agresividad del tumor. Su expresion esta asociada a un aumento del potencial metastasico que se verifica tanto en estudios animales, como en tumores humanos. La hipoxia tumoral se ha convertido en un factor clave en la progresion tumoral y se asocia a un mal pronostico, sobre todo en tumores de rinon y prostata. Este trabajo tiene por objetivo revisar la importancia de la hipoxia en la carcinogenesis y en la progresion tumoral, presentando una revision de los conocimientos actuales sobre el tema, mecanismos de accion y la activacion del HIF-1a.

Combined analysis of EGF+61G>A and TGFB1+869T>C functional polymorphisms in the time to androgen independence and prostate cancer susceptibility.

Proliferative mechanisms involving the epidermal growth factor (EGF) and transforming growth factor beta (TGF-β1) ligands are potential alternative pathways for prostate cancer (PC) progression to androgen independence (AI). Thus, the combined effect of EGF and TGFB1 functional polymorphisms might modulate tumor microenvironment and consequently its development. We studied EGF+61G>A and TGFB1+869T>C functional polymorphisms in 234 patients with PC and 243 healthy individuals. Intermediate- and high-proliferation genetic profile carriers have increased risk for PC (odds ratio (OR)=3.76, P=0.007 and OR=3.98, P=0.004, respectively), when compared with low proliferation individuals. Multivariate analysis showed a significantly lower time to AI in the high proliferation group, compared with the low/intermediate proliferation genetic profile carriers (HR=2.67, P=0.039), after adjustment for age, metastasis and stage. Results suggest that combined analysis of target genetic polymorphisms may contribute to the definition of cancer susceptibility and pharmacogenomic profiles. Combined blockage of key molecules in proliferation signaling pathways could be one of the most promising strategies for androgen-independent prostate cancer.

Human periprostatic white adipose tissue is rich in stromal progenitor cells and a potential source of prostate tumor stroma

A body of growing evidence now implicates white adipose tissue as a relevant source of stromal progenitor cells recruited to the tumor microenvironment to form supportive tumor stroma. While the role of periprostatic (PP) adipose tissue in prostate cancer progression has been barely appreciated, we sought to determine the progenitor cell population in PP adipose tissue and the association with prostate cancer. We isolated and characterized CD31−CD34+CD45−CD146− progenitor cells (adipose-derived stem cells [ASC]) in paired samples of PP and preperitoneal visceral adipose tissue from prostate tissue and peripheral blood mononuclear cells of prostate cancer and nodular prostatic hyperplasia patients. ASC were quantified by flow cytometry and confirmed through target gene expression. Here we show a significantly higher amount of ASC in PP than in visceral adipose tissue, independent of body mass index and prostatic disease. In the prostate, ASC are increased in cancer compared with prostatic nodular hyperplasia patients. Concordantly, adipsin gene (CFD) expression, which is known to be up-regulated in adipose stem cells, was overexpressed in PP adipose tissue, in the prostate of cancer patients and in prostate CD31−CD34+CD45−CD146− sorted cells. ASC were found at higher levels in the blood of prostate cancer patients simultaneously overweight/obese. Present findings indicate that PP adipose tissue is a reservoir of progenitor cells with the potential to migrate towards prostate tumors, although its clinical significance merits further evaluation.

The HIF1A functional genetic polymorphism at locus +1772 associates with progression to metastatic prostate cancer and refractoriness to hormonal castration.

The hypoxia inducible factor 1 alpha (HIF1a) is a key regulator of tumour cell response to hypoxia, orchestrating mechanisms known to be involved in cancer aggressiveness and metastatic behaviour. In this study we sought to evaluate the association of a functional genetic polymorphism in HIF1A with overall and metastatic prostate cancer (PCa) risk and with response to androgen deprivation therapy (ADT). The HIF1A +1772 C>T (rs11549465) polymorphism was genotyped, using DNA isolated from peripheral blood, in 1490 male subjects (754 with prostate cancer and 736 controls cancer-free) through Real-Time PCR. A nested group of cancer patients who were eligible for androgen deprivation therapy was followed up. Univariate and multivariate models were used to analyse the response to hormonal treatment and the risk for developing distant metastasis. Age-adjusted odds ratios were calculated to evaluate prostate cancer risk. Our results showed that patients under ADT carrying the HIF1A +1772 T-allele have increased risk for developing distant metastasis (OR, 2.0; 95%CI, 1.1-3.9) and an independent 6-fold increased risk for resistance to ADT after multivariate analysis (OR, 6.0; 95%CI, 2.2-16.8). This polymorphism was not associated with increased risk for being diagnosed with prostate cancer (OR, 0.9; 95%CI, 0.7-1.2). The HIF1A +1772 genetic polymorphism predicts a more aggressive prostate cancer behaviour, supporting the involvement of HIF1a in prostate cancer biological progression and ADT resistance. Molecular profiles using hypoxia markers may help predict clinically relevant prostate cancer and response to ADT.

Performance of an Adipokine Pathway-Based Multilocus Genetic Risk Score for Prostate Cancer Risk Prediction

Few biomarkers are available to predict prostate cancer risk. Single nucleotide polymorphisms (SNPs) tend to have weak individual effects but, in combination, they have stronger predictive value. Adipokine pathways have been implicated in the pathogenesis. We used a candidate pathway approach to investigate 29 functional SNPs in key genes from relevant adipokine pathways in a sample of 1006 men eligible for prostate biopsy. We used stepwise multivariate logistic regression and bootstrapping to develop a multilocus genetic risk score by weighting each risk SNP empirically based on its association with disease. Seven common functional polymorphisms were associated with overall and high-grade prostate cancer (Gleason≥7), whereas three variants were associated with high metastatic-risk prostate cancer (PSA≥20 ng/mL and/or Gleason≥8). The addition of genetic variants to age and PSA improved the predictive accuracy for overall and high-grade prostate cancer, using either the area under the receiver-operating characteristics curves (P<0.02), the net reclassification improvement (P<0.001) and integrated discrimination improvement (P<0.001) measures. These results suggest that functional polymorphisms in adipokine pathways may act individually and cumulatively to affect risk and severity of prostate cancer, supporting the influence of adipokine pathways in the pathogenesis of prostate cancer. Use of such adipokine multilocus genetic risk score can enhance the predictive value of PSA and age in estimating absolute risk, which supports further evaluation of its clinical significance.

Rotterdam Prostate Cancer Risk Calculator: Development and Usability Testing of the Mobile Phone App

Background The use of prostate cancer screening tools that take into account relevant prebiopsy information (ie, risk calculators) is recommended as a way of determining the risk of cancer and the subsequent need for a prostate biopsy. This has the potential to limit prostate cancer overdiagnosis and subsequent overtreatment. mHealth apps are gaining traction in urological practice and are used by both practitioners and patients for a variety of purposes. Objective The impetus of the study was to design, develop, and assess a smartphone app for prostate cancer screening, based on the Rotterdam Prostate Cancer Risk Calculator (RPCRC). Methods The results of the Rotterdam arm of the European Randomized Study of Screening for Prostate Cancer (ERSPC) study were used to elaborate several algorithms that allowed the risk of prostate cancer to be estimated. A step-by-step workflow was established to ensure that depending on the available clinical information the most complete risk model of the RPCRC was used. The user interface was designed and then the app was developed as a native app for iOS. The usability of the app was assessed using the Post-Study System Usability Questionnaire (PSSUQ) developed by IBM, in a group of 92 participants comprising urologists, general practitioners, and medical students. Results A total of 11 questions were built into the app, and, depending on the answers, one of the different algorithms of the RPCRC could be used to predict the risk of prostate cancer and of clinically significant prostate cancer (Gleason score ≥7 and clinical stage >T2b). The system usefulness, information quality, and interface quality scores were high—92% (27.7/30), 87% (26.2/30), and 89% (13.4/15), respectively. No usability problems were identified. Conclusions The RPCRC app is helpful in predicting the risk of prostate cancer and, even more importantly, clinically significant prostate cancer. Its algorithms have been externally validated before and the usability score shows the app’s interface is well designed. Further usability testing is required in different populations to verify these results and ensure that it is easy to use, to warrant a broad appeal, and to provide better patient care.

Molecular Study of the PCA3 Gene: Genotypic Analysis of PCA3 Polymorphism -845G>A and Metastatic Prostate Cancer

AIMS The prostate cancer gene 3 (PCA3) is a prostate-specific, non-protein-coding RNA. It is overexpressed in prostate cancer compared with the normal prostate and has a negative expression in other tissues. This case-control study sought to analyze the frequency of the polymorphism PCA3 -845 G>A in participants without prostate cancer and patients with metastatic prostate cancer. RESULTS Carriers of GA and AA genotype had a higher risk for metastatic prostate cancer (odds ratio [OR] for genotype GA, 1.79 [95% confidence interval (CI), 1.14-2.29]; p=0.007; OR for genotype AA, 2.38 [95% CI, 1.22-4.65]; p=0.006). Furthermore, the recessive model showed that A allele carriers have an increased risk for developing metastatic prostate cancer (OR, 1.91 [95% CI, 1.26-2.90]; p=0.001). CONCLUSIONS These results suggest a link between PCA3 and metastatic prostate cancer. The evaluation of individual genetic profiles, according to the PCA3 -845 G>A polymorphism, may elucidate the function of this gene and the mechanisms involved in its regulation and role in prostate cancer.