Publications by authors named "Vidya P Ramamurthy"

Triple-negative breast cancer (TNBC) and its recently identified subtype, quadruple negative breast cancer (QNBC), collectively account for approximately 13% of reported breast cancer cases in the United States. These aggressive forms of breast cancer are associated with poor prognoses, limited treatment options, and lower overall survival rates. In previous studies, our research demonstrated that VNLG-152R exhibits inhibitory effects on TNBC cells both and and the deuterated analogs were more potent inhibitors of TNBC cells Building upon these findings, our current study delves into the molecular mechanisms underlying this inhibitory action.

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These studies compared the efficacies of our clinical agent galeterone (Gal) and the FDA-approved prostate cancer drug, enzalutamide (ENZ) with two lead next generation galeterone analogs (NGGAs), VNPP414 and VNPP433-3β, using prostate cancer (PC) in vitro and in vivo models. Antitumor activities of orally administered agents were also assessed in CWR22Rv1 tumor-bearing mice. We demonstrated that Gal and NGGAs degraded AR/AR-V7 and Mnk1/2; blocked cell cycle progression and proliferation of human PC cells; induced apoptosis; inhibited cell migration, invasion, and putative stem cell markers; and reversed the expression of epithelial-to-mesenchymal transition (EMT).

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Currently, there are no effective therapies for patients with triple-negative breast cancer (TNBC), an aggressive and highly metastatic disease. Activation of eukaryotic initiation factor 4E (eIF4E) by mitogen-activated protein kinase (MAPK)-interacting kinases 1 and 2 (Mnk1/2) play a critical role in the development, progression and metastasis of TNBC. Herein, we undertook a comprehensive study to evaluate the activity of a first-in-class Mnk1/2 protein degraders, racemic VNLG-152R and its two enantiomers (VNLG-152E1 and VNLG-152E2) in in vitro and in vivo models of TNBC.

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VNLG-152 is a novel retinamide (NR) shown to suppress growth and progression of genetically diverse prostate cancer cells via inhibition of androgen receptor signaling and eukaryotic initiation factor 4E (eIF4E) translational machinery. Herein, we report therapeutic effects of VNLG-152 on castration-resistant prostate cancer (CRPC) growth and metastatic phenotype in a CRPC tumor xenograft model. Administration of VNLG-152 significantly and dose-dependently suppressed the growth of aggressive CWR22Rv1 tumors by 63.

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Survival rate for pancreatic cancer (pancreatic ductal adenocarcinoma, PDAC) is poor, with about 80% of patients presenting with the metastatic disease. Gemcitabine, the standard chemotherapeutic agent for locally advanced and metastatic PDAC has limited efficacy, attributed to innate/acquired resistance and activation of pro-survival pathways. The Mnk1/2-eIF4E and NF-κB signaling pathways are implicated in PDAC disease progression/metastasis and also associated with gemcitabine-induced resistance in PDAC.

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Purpose Of Review: The current overview will summarize some of the developments in the area of protein translation, including their relation to the therapeutic targeting of prostate cancer.

Recent Findings: Translational control, mediated by the rate-limiting eukaryotic translation initiation factor 4E (eIF4E), drives selective translation of several oncogenic proteins, thereby contributing to tumor growth, metastasis, and treatment resistance in various cancers, including prostate cancer. As an essential regulatory hub, several oncogenic hyperactive signaling pathways appear to converge on eIF4E to promote tumorigenesis.

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Prostate cancer (PCa) is the most frequently diagnosed non-cutaneous malignancy and leading cause of cancer mortality in men. At the initial stages, prostate cancer is dependent upon androgens for their growth and hence effectively combated by androgen deprivation therapy (ADT). However, most patients eventually recur with an androgen deprivation-resistant phenotype, referred to as castration-resistant prostate cancer (CRPC), a more aggressive form for which there is no effective therapy presently available.

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Degradation of all forms of androgen receptors (ARs) is emerging as an advantageous therapeutic paradigm for the effective treatment of prostate cancer. In continuation of our program to identify and develop improved efficacious novel small-molecule agents designed to disrupt AR signaling through enhanced AR degradation, we have designed, synthesized, and evaluated novel C-3 modified analogues of our phase 3 clinical agent, galeterone (5). Concerns of potential in vivo stability of our recently discovered more efficacious galeterone 3β-imidazole carbamate (6) led to the design and synthesis of new steroidal compounds.

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Galeterone (Gal) is a first-in-class multi-target oral small molecule that will soon enter pivotal phase III clinical trials in castration resistant prostate cancer (CRPC) patients. Gal disrupts androgen receptor (AR) signaling via inhibition of CYP17, AR antagonism and AR degradation. Resistance to current therapy is attributed to up-regulation of full-length AR (fAR), splice variants AR (AR-Vs) and AR mutations.

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The synthesis and in vitro and in vivo antibreast and antiprostate cancers activities of novel C-4 heteroaryl 13-cis-retinamides that modulate Mnk-eIF4E and AR signaling are discussed. Modifications of the C-4 heteroaryl substituents reveal that the 1H-imidazole is essential for high anticancer activity. The most potent compounds against a variety of human breast and prostate cancer (BC/PC) cell lines were compounds 16 (VNHM-1-66), 20 (VNHM-1-81), and 22 (VNHM-1-73).

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Androgen receptor (AR) and MNK activated eIF4E signaling promotes the development and progression of prostate cancer (PCa). In this study, we report that our Novel Retinamides (NRs) target both AR signaling and eIF4E translation in androgen sensitive and castration resistant PCa cells via enhancing AR and MNK degradation through ubiquitin-proteasome pathway. Dual blockade of AR and MNK initiated eIF4E activation by NRs in turn induced cell cycle arrest, apoptosis, and inhibited cell proliferation.

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Resistance to aromatase inhibitors is a major concern in the treatment of breast cancer. Long-term letrozole cultured (LTLC) cells represent a model of resistance to aromatase inhibitors. The LTLC cells were earlier generated by culturing MCF-7Ca, the MCF-7 human breast cancer cell line stably transfected with human placental aromatase gene for a prolonged period in the presence of letrozole.

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Some retinoic acid metabolism blocking agents (RAMBAs) are known to exhibit a wide range of anticancer activities by mechanisms that are still not completely resolved. This study investigated the anticancer efficacy and mechanism(s) of novel RAMBA retinamides (RRs) in triple negative and Her-2 overexpressing breast cancer cells. Specifically, we examined the possibility that RRs affect the translational machinery in these breast cancer (BC) cells.

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