Prostate cancer remains one of the most prevalent cancers in aging men. Active surveillance subpopulation of patients with prostate cancer includes men with varying cancer risk categories of precancerous disease due to prostatic intraepithelial neoplasia (PIN) heterogeneity. Identifying molecular alterations associated with PIN can provide preventable measures through finding novel pharmacologic targets for cancer interception. Targeted nutritional interception may prove to be the most appropriate chemoprevention for intermediate- and high-risk active surveillance patients. Here, we have generated two prostate-specific transgenic mouse models, one overexpressing MTA1 (R26MTA1) and the other overexpressing MTA1 on the background of Pten heterozygosity (R26MTA1; Pten+/f), in which we examined the potential chemopreventive efficacy of dietary pterostilbene. We show that MTA1 promotes neoplastic transformation of prostate epithelial cells by activating cell proliferation and survival, leading to PIN development. Moreover, MTA1 cooperates with PTEN deficiency to accelerate PIN development by increasing cell proliferation and MTA1-associated signaling. Further, we show that mice fed with a pterostilbene-supplemented diet exhibited more favorable histopathology with decreased severity and number of PIN foci accompanied by reduced proliferation, angiogenesis, and inflammation concomitant to reduction in MTA1 and MTA1-associated CyclinD1, Notch2, and oncogenic miR-34a and miR-22 levels. Prevention Relevance: Developing novel interceptive strategies for prostate cancer chemoprevention is a paramount goal in clinical oncology. We offer preclinical evidence for the potential of pterostilbene as a promising natural agent for MTA1-targeted interceptive strategy in future cancer prevention trials towards protecting select patients with prostate cancer under active surveillance from developing cancer.

Natural stilbenes have gained significant attention in the scientific community owing to their potential anticancer effects against prostate cancer. We recently reported that Gnetin C, a resveratrol (Res) dimer, demonstrated more potent inhibition of metastasis-associated protein 1/v-ets avian erythroblastosis virus E26 oncogene homolog 2 (MTA1/ETS2) axis in prostate cancer cell lines than other stilbenes. In this study, we investigated in vivo antitumor effects of Gnetin C in two doses (50 and 25 mg/kg, i.p.) using PC3M-Luc subcutaneous xenografts and compared these to Res and pterostilbene (Pter). We found that while vehicle-treated mice revealed rapid tumor progression, compounds-treated mice showed noticeable delay in tumor growth. Gnetin C in 50 mg/kg dose demonstrated the most potent tumor inhibitory effects. Gnetin C in 25 mg/kg dose exhibited tumor inhibitory effects comparable with Pter in 50 mg/kg dose. Consistent with the effective antitumor effects, Gnetin C-treated tumors showed reduced mitotic activity and angiogenesis and a significant increase in apoptosis compared to all the other groups. The data suggest that Gnetin C is more potent in slowing tumor progression in prostate cancer xenografts than Res or Pter. Taken together, we demonstrated, for the first time, that Gnetin C is a lead compound among stilbenes for effectively blocking prostate cancer progression in vivo.

The SARS-CoV-2 virus emerged as a major cause of the COVID-19 pandemic in December 2019. Many attempts have been made to block the viral infection by targeting various processes like its entry, uncoating, replication, activating T cells response, and rising antibody titer. Also, many drugs are repurposed like remdesivir, dexamethasone, tocilizumab, hydroxychloroquine based on their established therapeutic efficacy against other viruses in the past. Natural products (NP) consist of a promising candidate and are needed to evaluate those molecules with molecular docking for preliminary screening and in vitro studies. Therefore, in the present study, a total of 12 active constituents from natural products like Ashwagandha, Tinospora cordifolia, Tea, Neem and lemon balm were docked, using the Autodock tool, onto the crystal structure of SARS CoV-2 main protease (PDB ID-5R80), to study their capability to act as main protease (Mpro) COVID-19 inhibitors. All NPs derivatives displayed good binding energies (ΔG) ranging from -8.8 to -5.2 kcal/mol, but berberine, epicatechin, and rosmarinic acid were found most potent, among others. Therefore, good binding energy, drug-likeness, and efficient pharmacokinetics suggest the potential of NPs derivatives as SARS-CoV-2 main protease (Mpro) inhibitors. However, further research is necessary to investigate the ability of these compounds as COVID-19 inhibitors.

<p>Supplementary Figure 1: A, transgene integration and genotyping scheme of MTA1 transgenic animals. B, genotyping of MTA1 founder 870#2. Supplementary Figure 2: A, average body weight of mice fed different diets during 22 weeks (monitored weekly). B, effect of PTER-Diet on food intake (g). Supplementary Table 1: Nutritional composition of diets. Supplementary Table 2: Primers for genotyping used in this study. Supplementary Table 3: Antibodies for immunoblots and IHC used in this study. Supplementary Table 4: Primers for qRT-PCR used in this study.</p>

<p>Supplementary Figure 1: A, transgene integration and genotyping scheme of MTA1 transgenic animals. B, genotyping of MTA1 founder 870#2. Supplementary Figure 2: A, average body weight of mice fed different diets during 22 weeks (monitored weekly). B, effect of PTER-Diet on food intake (g). Supplementary Table 1: Nutritional composition of diets. Supplementary Table 2: Primers for genotyping used in this study. Supplementary Table 3: Antibodies for immunoblots and IHC used in this study. Supplementary Table 4: Primers for qRT-PCR used in this study.</p>