10 research outputs found
Novel AR/AR-V7 and Mnk1/2 Degrader, VNPP433-3β: Molecular Mechanisms of Action and Efficacy in AR-Overexpressing Castration Resistant Prostate Cancer In Vitro and In Vivo Models
Prostate cancer (PCa) relies in part on AR-signaling for disease development and progression. Earlier, we developed drug candidate galeterone, which advanced through phase 2-clinical trials in treating castration-resistant PCa (CRPC). Subsequently, we designed, synthesized, and evaluated next-generation galeterone-analogs including VNPP433-3β which is potently efficacious against pre-clinical models of PCa. This study describes the mechanism of action of VNPP433-3β that promotes degradation of full-length AR (fAR) and its splice variant AR-V7 besides depleting MNK1/2 in in vitro and in vivo CRPC models that stably overexpresses fAR. VNPP433-3β directly engages AR within the cell and promotes proteasomal degradation of fAR and its splice variant AR-V7 by enhancing the interaction of AR with E3 ligases MDM2/CHIP but disrupting AR-HSP90 binding. Next, VNPP433-3β decreases phosphorylation of 4EBP1 and abates binding of eIF4E and eIF4G to 5′ cap of mRNA by depleting MNK1/2 with consequent depletion of phosphorylated eIF4E. Finally, RNA-seq demonstrates modulation of multiple pathways that synergistically contribute to PCa inhibition. Therefore, VNPP433-3β exerts its antitumor effect by imposing 1) transcriptional regulation of AR and AR-responsive oncogenes 2) translational regulation by disrupting mRNA-5′cap-dependent translation initiation, 3) reducing AR half-life through enhanced proteasomal degradation in vitro and AR-overexpressing tumor xenografts in vivo
Genotyping of high-risk anal human papillomavirus (HPV): ion torrent-next generation sequencing vs. linear array
Abstract Background Our next generation sequencing (NGS)-based human papillomavirus (HPV) genotyping assay showed a high degree of concordance with the Roche Linear Array (LA) with as little as 1.25 ng formalin-fixed paraffin-embedded-derived genomic DNA in head and neck and cervical cancer samples. This sensitive genotyping assay uses barcoded HPV PCR broad-spectrum general primers 5+/6+ (BSGP)5+/6+ applicable to population studies, but it’s diagnostic performance has not been tested in cases with multiple concurrent HPV infections. Methods We conducted a cross-sectional study to compare the positive and negative predictive value (PPV and NPV), sensitivity and specificity of the NGS assay to detect HPV genotype infections as compared to the LA. DNA was previously extracted from ten anal swab samples from men who have sex with men in Nigeria enrolled on the TRUST/RV368 cohort study. Two-sample tests of proportions were used to examine differences in the diagnostic performance of the NGS assay to detect high vs. low-risk HPV type-specific infections. Results In total there were 94 type-specific infections detected in 10 samples with a median of 9.5, range (9 to 10) per sample. Using the LA as the gold standard, 84.4% (95% CI: 75.2–91.2) of the same anal type-specific infections detected on the NGS assay had been detected by LA. The PPV and sensitivity differed significantly for high risk (PPV: 90%, 95% CI: 79.5–96.2; sensitivity: 93.1%, 95% CI: 83.3–98.1) as compared to low risk HPV (PPV: 73%, 95% CI: 54.1–87.7; sensitivity: 61.1, 95% CI: 43.5–76.9) (all p < 0.05). The NPV for all types was 92.5% (95% CI: 88.4–95.4). The NPV and specificity were similar for high and low risk HPVs (all p > 0.05). The NGS assay detected 10 HPV genotypes that were not among the 37 genotypes found on LA (30, 32, 43, 44, 74, 86, 87, 90, 91, 114). Conclusions The NGS assay accurately detects multiple HPV infections in individual clinical specimens with limited sample volume and has extended coverage compared to LA
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Evaluating the Jaccard Similarity Index as a Persistence Measure of Multiple Anal Human Papillomavirus Among Nigerian Men Who Have Sex With Men.
BackgroundMultiple anal human papillomavirus (HPVs) may increase the risk of anal cancer among men who have sex with men (MSM) living with human immunodeficiency virus (HIV). The Jaccard Similarity Index (JSI) was explored as a measure of multiple HPV persistence.MethodsThe TRUST/RV368 cohort enrolled MSM living with and without HIV in Abuja and Lagos, Nigeria. Participants with anal swabs at baseline, 3- and 12-month visits were tested for high- and low-risk HPVs using a next-generation sequencing assay. Persistence of the same HPV genotypes over time was calculated using the JSI and categorized into high, medium, and low similarity tertiles. Factors associated with higher versus lower similarity were estimated with multivariable ordinal logistic regression and reported as adjusted odds ratios (aORs) and 95% confidence intervals (CIs).ResultsOf the 225 participants, median age was 25 years (interquartile range, 22-29 years), 62% were living with HIV, median HPVs was 3 (interquartile range, 2-5), and HPV6 (28%), HPV16 (26%), HPV11 (23%), and HPV45 (20%) were most prevalent. Fifty-three percent of participants had highly similar HPVs at 3 months, and the similarity was associated with HIV (aOR, 3.11; 95% CI, 1.6-5.9) and recent receptive sex (aOR, 1.9; 95% CI, 1.0-3.5). By 12 months, 20% had highly similar HPVs, and it was associated with 12 years or longer since anal coital debut (aOR, 6.8; 95% CI, 3.1-5.2), self-reported genital warts (aOR, 3.1; 95% CI, 1.5-6.6), and 200 or less CD4 cells/mm3 (aOR, 13.3; 95% CI, 2.7-65.2) for those living with HIV.ConclusionsStudies evaluating the JSI as a predictor of high-grade intraepithelial lesions would further confirm its applicability as a quantitative measure of multiple HPV persistence
Multiple HPV infections among men who have sex with men engaged in anal cancer screening in Abuja, Nigeria
Background: Anal precancers and cancers can be detected during screening with high-resolution anoscopy (HRA). The sensitivity of HRA depends on the burden and duration of human papillomavirus (HPV) among those screened as well as anoscopist proficiency, which is highly correlated with prior screening experience. Our objective was to compare the identification and type of HPV and the likelihood of HRA-detected precancer for men who have sex with men (MSM) undergoing their first HRA-screening in Nigeria. Methods: MSM were recruited from an HIV test-and-treat cohort, TRUST/RV368, into a new anal cancer screening program. Anal swabs obtained during screening underwent Ion Torrent next-generation sequencing using barcoded HPV PCR broad-spectrum primers 5+/6+ to detect up to 161 HPVs. All high-risk (HR) HPVs and the most abundant low-risk (LR)-HPVs were evaluated as type-specific infections with some categorized as belonging to a multiple infection. HRA screening results included benign, low-grade squamous intraepithelial lesions (LSIL), or HSIL as detected by cytology or histology. Multivariable logistic regression was used to assess the association of HPV and other cofactors with any SIL. Results: Among 342 MSM, 60% were HIV-infected, 89% were under 35 years of age, and 51% had 8 or more years since anal coital debut. Of those with SIL, 89% had LSIL and only 11% had HSIL. Prevalence of any HPV and high-risk (HR)-HPV was 92% and 74%, respectively. The most prevalent genotypes in rank order were HPV6 (31%), HPV16 (23%), HPV42 (20%), HPV11 (18%), HPV45 (18%), and HPV51 (17%). For multiple HR-HPVs, 31% had a single HR-HPV, 32% had 2-3, and 10% had 4 or more. Low-risk HPVs, type 6 and/or 11, were common (42%) and were significantly associated with SIL (adjusted odds ratio [aOR]:1.8, 95% confidence interval [CI]: 1.1–3.1) together with perianal warts (aOR:6.7, 95% CI: 3.3–13.5). In contrast, HR-HPV and multiple HR-HPVs were not significantly associated with SIL (all p \u3e 0.05). Conclusions: Detection of HSIL was low. Although HR-HPV was abundant, HSIL development also depends on the duration of HR-HPV infections and the anoscopist\u27s level of experience. As our cohort ages and the anoscopist becomes more skilled, detection of HSIL will likely improve