N6‐methyladenosine (m6A) modification of mRNA mediates diverse cellular and viral functions. Infection with Epstein–Barr virus (EBV) is causally associated with nasopharyngeal carcinoma (NPC), 10% of gastric carcinoma, and various B‐cell lymphomas, in which the viral latent and lytic phases both play vital roles. Here, we show that EBV transcripts exhibit differential m6A modification in human NPC biopsies, patient‐derived xenograft tissues, and cells at different EBV infection stages. m6A‐modified EBV transcripts are recognized and destabilized by the YTHDF1 protein, which leads to the m6A‐dependent suppression of EBV infection and replication. Mechanistically, YTHDF1 hastens viral RNA decapping and mediates RNA decay by recruiting RNA degradation complexes, including ZAP, DDX17, and DCP2, thereby post‐transcriptionally downregulating the expression of EBV genes. Taken together, our results reveal the critical roles of m6A modifications and their reader YTHDF1 in EBV replication. These findings contribute novel targets for the treatment of EBV‐associated cancers.
Adipose tissue plays an important role in regulating female fertility, owing to not only its energy stores but also the endocrine actions of secreted adipokines. As one of the adipokines, adiponectin is almost exclusively secreted from the fat, and its circulating concentration is paradoxically reduced in obesity. Although recent studies implied a purported positive role of adiponectin in ovarian functions, definitive in vivo evidence has been sorely lacking. We have consistently observed subfertility in female adiponectin null mice and therefore postulated a protective role of adiponectin in ovarian functions. Female adiponectin null mice displayed impaired fertility, reduced retrieval of oocytes, disrupted estrous cycle, elevated number of atretic follicles, and impaired late folliculogenesis. Analysis of their sera revealed a significant decrease in estradiol and FSH but an increase in LH and testosterone at proestrus. In addition, we found marked reduction of progesterone levels at diestrus, a significant decrease in LH receptor expression as well as in the number of GnRH immunoreactive neurons. Adiponectin deficiency also altered the peak concentrations of LH surge and led to lower expression of Cytochrome P450 family 11 subfamily A member 1 (P450scc), an enzyme critical for progesterone synthesis, as well as an increase in BCL2 associated X, apoptosis regulator and Insulin like growth factor binding protein 4 in atretic follicles. These physiological and molecular events were independent of insulin sensitivity. Thus, we have revealed a novel mechanism linking adiponectin and female fertility that entails regulation of reproductive hormone balance and ovarian follicle development.
Peptide functionalized pH sensitive raloxifene-chitosan nanoparticles with high biocompatibility synergistically inhibit tumor growth and angiogenesis in breast cancer.
Hepatocellular carcinoma (HCC) is the fourth largest cause of cancer-related deaths worldwide with limited therapeutic interventions. Renewed interest in natural products as drug leads has resulted in a paradigm shift toward the rapid screening of medicinal plants for the discovery of new chemical entities. Rotundic acid (RA), a plant-derived triterpenoid, has been anecdotally reported to possess anti-inflammatory and cardio-protective abilities. The present study highlights the anti-cancer efficacy of RA on HCC
in vitro
and
in vivo
. The inhibitory effects of RA on HCC cell viability was determined by MTT. Soft agar colony formation and clonogenic assays also showed that RA inhibited HCC cell proliferation. Flow cytometry, confocal, and western blot results further indicated that RA induced cell cycle arrest, DNA damage, and apoptosis by modulating the AKT/mTOR and MAPK pathways. Besides the suppression of migration and invasion, tube formation and VEGF-ELISA revealed the anti-angiogenic abilities of RA on HCC. Moreover, RA also inhibited tumor growth in a HepG2 xenograft mouse model. To our best knowledge, this is the first extensive study of the anticancer activity of RA on HCC. The results demonstrate that RA could be a potential drug candidate for HCC treatment.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.