Yong Zhu

Background: A worldwide higher incidence of prostate cancer and lower incidence of testicular cancer in men of African ancestry compared to European ancestry has been observed previously. However, underlying mechanisms accounting for these observations are largely unknown.Methods: The current study analyzed previously reported SNPs associated with either prostate cancer or testicular cancer to examine whether the risk allele frequency could help us understand the observed incidence disparities in men of African ancestry and European ancestry. Both t-test and regression analysis were performed.Results: Here we show that men of African ancestry are more likely to have risk alleles of prostate cancer and less likely to have risk alleles of testicular cancer compared to men of European ancestry.Conclusions: Our findings suggest that genetic factors may play an important role in the racial disparities in the risk of prostate and testicular cancers.

Can Muscle Building Supplements Increase Testicular Cancer Risk?

Background: Light at night (LAN) as a circadian disruption factor may affect the human immune system and consequently increase an individual’s susceptibility to the severity of infectious diseases, such as COVID-19. COVID-19 infections spread differently in each state in the United States (US). The current analysis aimed to test whether there is an association between LAN and COVID-19 cases in 4 selected US states: Connecticut, New York, California, and Texas. Methods: We analyzed clustering patterns of COVID-19 cases in ArcMap and performed a multiple linear regression model using data of LAN and COVID-19 incidence with adjustment for confounding variables including population density, percent below poverty, and racial factors. Results: Hotspots of LAN and COVID-19 cases are located in large cities or metro-centers for all 4 states. LAN intensity is associated with cases/1 k for overall and lockdown durations in New York and Connecticut (P < 0.001), but not in Texas and California. The overall case rates are significantly associated with LAN in New York (P < 0.001) and Connecticut (P < 0.001). Conclusions: We observed a significant positive correlation between LAN intensity and COVID-19 cases-rate/1 k, suggesting that circadian disruption of ambient light may increase the COVID-19 infection rate possibly by affecting an individual’s immune functions. Furthermore, differences in the demographic structure and lockdown policies in different states play an important role in COVID-19 infections.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

BackgroundMicroRNA-154 (hsa-miR-154) is a novel miRNA. Emerging information shows that hsa-miR-154 participates in multiple physiological and pathological processes and is generally identified as a tumor suppressor in multiple types of cancers. Methylation of the hsa-miR-154 gene could also be altered by circadian disruption associated with night shiftwork. ResultsIn this study, we tested whether hsa-miR-154 expression is downregulated in breast cancer and whether hsa-miR-154 targets any circadian genes. Using publicly available datasets and bioinformatics analysis, we first demonstrated that expression levels of hsa-miR-154 were significantly lower in breast tumors compared to normal breast tissues and its expression correlated with clinical outcomes. Downregulation of hsa-miR-154 was also confirmed in breast cancer cell lines and restoration of hsa-miR-154 by transfection significantly inhibited growth of these cells. Further bioinformatics screening indicated that the circadian gene CLOCK is likely a hsa-miR-154 target. ConclusionsThese findings suggest a potential tumor suppressing role of hsa-miR-154 in breast cancer that acts by targeting CLOCK gene. Exploration of hsa-miR-154 for its anti-cancer effect may provide information on its potential for therapeutic application.

Background: Light at night (LAN) as a circadian disruption factor may affect the human immune system and consequently increase an individual’s susceptibility or the severity of infectious diseases, such as COVID-19. COVID-19 infections spread differently in each state in the United States (US). The current analysis aimed to test whether there is an association between LAN and COVID-19 cases in 4 selected US states: Connecticut, New York, California, and Texas.Methods: We analyzed clustering patterns of COVID-19 cases in ArcMap and performed a multiple linear regression model using data of LAN and COVID-19 incidence with adjustment for confounding variables including population density, percent below poverty, and racial factors. Results: Hotspots of LAN and COVID-19 cases are located in large cities or metro-centers for all 4 states. LAN intensity is associated with cases/1k for overall and lockdown durations in New York and Connecticut (P Conclusions: We observed a significant positive correlation between LAN intensity and COVID-19 cases-rate/1k, suggesting that circadian disruption of ambient light may increase the COVID-19 infection rate possibly by affecting an individual's immune functions. Furthermore, differences in the demographic structure and lockdown policies in different states play an important role in COVID-19 infections.

Valerian root (Valeriana officinalis) is a popular and widely available herbal supplement used to treat sleeping disorders and insomnia. The herb’s ability to ameliorate sleep dysfunction may signify an unexplored anti-tumorigenic effect due to the connection between circadian factors and tumorigenesis. Of particular interest are the structural similarities shared between valeric acid, valerian's active chemical ingredient, and certain histone deacteylase (HDAC) inhibitors, which imply that valerian may play a role in epigenetic gene regulation. In this study, we tested the hypothesis that the circadian-related herb valerian can inhibit breast cancer cell growth and explored epigenetic changes associated with valeric acid treatment. Our results showed that aqueous valerian extract reduced growth of breast cancer cells. In addition, treatment of valeric acid was associated with decreased breast cancer cell proliferation, migration, colony formation and 3D formation in vitro in a dose- and time-dependent manner, as well as reduced HDAC activity and a global DNA hypomethylation. Overall, these findings demonstrate that valeric acid can decrease the breast cancer cell proliferation possibly by mediating epigenetic modifications such as the inhibition of histone deacetylases and alterations of DNA methylation. This study highlights a potential utility of valeric acid as a novel HDAC inhibitor and a therapeutic agent in the treatment of breast cancer.