Genistein chemoprevention of prostate cancer in TRAMP mice

Epidemiological studies suggest an inverse association between soy intake and prostate cancer risk. Genistein, the predominant phytoestrogen in soy food, has been proposed as a potential chemopreventive agent due to its anti-estrogen and tyrosine kinase inhibitory effects. To determine the most effective period for genistein chemoprevention, the Transgenic adenocarcinoma mouse prostate (TRAMP) model was used. The treatments were 250 mg genistein/kg AIN-76A diet 1) prepubertally only, 2) in adulthood only or 3) through out life. Controls received AIN-76A diet. By 28 weeks of age, 100% TRAMP mice fed control diet developed prostatic intraepithelial neoplasia (PIN) or adenocarcinomas with 6%, 16%, 44% and 34% developing high grade PIN, well differentiated, moderately differentiated and poorly differentiated prostatic adenocarcinomas, respectively. Prepubertal only (1–35 days postpartum) and adult only genistein treatments (12 – 28 weeks) resulted in 6% and 29% decreases in poorly-differentiated cancerous lesions compared with controls, respectively. The most significant effect was seen in the TRAMP mice exposed to genistein throughout life (1–28 weeks) with a 50% decrease in poorly-differentiated cancerous lesions. In a separate experiment in castrated TRAMP mice, dietary genistein suppressed the development of advanced prostate cancer by 35% compared with controls. Of the tumors that developed in castrated TRAMP mice, 100% were poorly-differentiated in contrast to the 37% of noncastrated TRAMP mice that developed poorly-differentiated tumors. ICI 182,780 (ICI), genistein and estrogen down-regulated androgen receptor (AR), estrogen receptor alpha (ER-α) and progesterone receptor (PR) in the prostates of C57BL/6 mice, and act independently of ER. Our data obtained in intact and castrated transgenic mice suggest that genistein may be a promising chemopreventive agent against androgen-dependent and independent prostate cancers

Interactions between Cells with Distinct Mutations in c-MYC and Pten in Prostate Cancer

In human somatic tumorigenesis, mutations are thought to arise sporadically in individual cells surrounded by unaffected cells. This contrasts with most current transgenic models where mutations are induced synchronously in entire cell populations. Here we have modeled sporadic oncogene activation using a transgenic mouse in which c-MYC is focally activated in prostate luminal epithelial cells. Focal c-MYC expression resulted in mild pathology, but prostate-specific deletion of a single allele of the Pten tumor suppressor gene cooperated with c-MYC to induce high grade prostatic intraepithelial neoplasia (HGPIN)/cancer lesions. These lesions were in all cases associated with loss of Pten protein expression from the wild type allele. In the prostates of mice with concurrent homozygous deletion of Pten and focal c-MYC activation, double mutant (i.e. c-MYC+;Pten-null) cells were of higher grade and proliferated faster than single mutant (Pten-null) cells within the same glands. Consequently, double mutant cells outcompeted single mutant cells despite the presence of increased rates of apoptosis in the former. The p53 pathway was activated in Pten-deficient prostate cells and tissues, but c-MYC expression shifted the p53 response from senescence to apoptosis by repressing the p53 target gene p21Cip1. We conclude that c-MYC overexpression and Pten deficiency cooperate to promote prostate tumorigenesis, but a p53-dependent apoptotic response may present a barrier to further progression. Our results highlight the utility of inducing mutations focally to model the competitive interactions between cell populations with distinct genetic alterations during tumorigenesis

Identification of Distinct Heterogenic Subtypes and Molecular Signatures Associated with African Ancestry in Triple Negative Breast Cancer Using Quantified Genetic Ancestry Models in Admixed Race Populations

Triple negative breast cancers (TNBCs) are molecularly heterogeneous, and the link between their aggressiveness with African ancestry is not established. We investigated primary TNBCs for gene expression among self-reported race (SRR) groups of African American (AA, n = 42) and European American (EA, n = 33) women. RNA sequencing data were analyzed to measure changes in genome-wide expression, and we utilized logistic regressions to identify ancestry-associated gene expression signatures. Using SNVs identified from our RNA sequencing data, global ancestry was estimated. We identified 156 African ancestry-associated genes and found that, compared to SRR, quantitative genetic analysis was a more robust method to identify racial/ethnic-specific genes that were differentially expressed. A subset of African ancestry-specific genes that were upregulated in TNBCs of our AA patients were validated in TCGA data. In AA patients, there was a higher incidence of basal-like two tumors and altered TP53, NFB1, and AKT pathways. The distinct distribution of TNBC subtypes and altered oncologic pathways show that the ethnic variations in TNBCs are driven by shared genetic ancestry. Thus, to appreciate the molecular diversity of TNBCs, tumors from patients of various ancestral origins should be evaluated

Cervical Precancer Risk in HIV-Infected Women Who Test Positive for Oncogenic Human Papillomavirus Despite a Normal Pap Test

Background. Determining cervical precancer risk among human immunodeficiency virus (HIV)–infected women who despite a normal Pap test are positive for oncogenic human papillomavirus (oncHPV) types is important for setting screening practices

Novel approaches to smoothing and comparing SELDI TOF spectra

Abstract: Background: Most published literature using SELDI-TOF has used traditional techniques in Spectral Analysis such as Fourier transforms and wavelets for denoising. Most of these publications also compare spectra using their most prominent feature, ie, peaks or local maximums. Methods: The maximum intensity value within each window of differentiable m/z values was used to represent the intensity level in that window. We also calculated the ‘Area under the Curve’ (AUC) spanned by each window. Results: Keeping everything else constant, such as pre-processing of the data and the classifier used, the AUC performed much better as a metric of comparison than the peaks in two out of three data sets. In the third data set both metrics performed equivalently. Conclusions: This study shows that the feature used to compare spectra can have an impact on the results of a study attempting to identify biomarkers using SELDI TOF data

Synchronous and metachronous bilateral breast cancer: clinicopathologic characteristics and prognostic outcomes

The incidence of bilateral breast cancer (BBC) reportedly ranges from 1.4 to 11.8%. Women with a first primary breast cancer are at a 2- to 6-fold increased risk of developing contralateral BC. However, there have been limited studies analyzing the clinicopathologic features of BBC and conflicting data exist on the prognostic significance of BBC. In this study, we sought to analyze the incidence of BBC in the era of modern medicine and assess the clinicopathologic characteristics and prognostic outcomes compared to unilateral BC (UBC). Of the 5941 patients with stage I-III BC diagnosed between 1998 and 2013 at our institution, 110 developed BBC, including 58 synchronous BBC (SBBC, interval between the first and the contralateral BC ≤3 months) and 52 metachronous BBC (MBBC, interval \u3e3 months). The median time to the second tumor was 67.9 months among patients with MBBC. BBC was associated with a significantly lower rate of having a ductal type, high grade, HER2-positive or node-positive disease when compared to UBC, while no difference was found for age, race, ER/PR status, or pathologic tumor stage. When compared to MBBC, SBBC was strongly associated with a lobular phenotype, non-high grade, and ER/PR-positive disease; and further demonstrated a significantly higher concordant rate for ER, PR, and HER2 status. Patients with BBC had a significantly worse distant relapse-free survival (RFS) but a similar disease-specific survival (DSS) when compared to those with UBC. Being African American, having a high histologic grade and higher pathologic tumor or node stage was significantly associated with a worse prognosis, while SBBC was associated with a favorable RFS by multivariate analysis. Nodal status was the only independent prognosticator for DSS in patients with BBC. Further investigation into the complex biologic and clinical behavior of BBC may provide novel insights into the therapeutic strategies in the pursuit of precision medicine in this unique subset of patients