O-GlcNAcylation of YY1 stimulates tumorigenesis in colorectal cancer cells by targeting SLC22A15 and AANAT.

Emerging studies have revealed that O-GlcNAcylation plays pivotal roles in the tumorigenesis of colorectal cancers (CRCs). However, the underlying mechanism still remains largely unknown. Here, we demonstrated that Yin Yang 1 (YY1) was O-GlcNAcylated by O-GlcNAc transferase (OGT) and O-GlcNAcylation of YY1 could increase the protein expression by enhancing its stability. O-GlcNAcylation facilitated transformative phenotypes of CRC cell in a YY1-dependent manner. Also, O-GlcNAcylation stimulates YY1-dependent transcriptional activity. Besides, we also identified the oncoproteins, SLC22A15 and AANAT, which were regulated by YY1 directly, are responsible for the YY1 stimulated tumorigenesis. Furthermore, we identified the main putative O-GlcNAc site of YY1 at Thr236, and mutating of this site decreased the pro-tumorigenic capacities of YY1. We concluded that O-GlcNAcylation of YY1 stimulates tumorigenesis in CRC cells by targeting SLC22A15 and AANAT, suggesting that YY1 O-GlcNAcylation might be a potential effective therapeutic target for treating CRC.

(-)-Guaiol regulates autophagic cell death depending on mTOR signaling in NSCLC.

(-)-Guaiol, a sesquiterpene alcohol with the guaiane skeleton, has been found in many Chinese medicinal plants and been reported to comprise various guaiane natural products that are well known for their antibacterial activities. Previously, we have shown its antitumor activity by inducing autophagy in NSCLC cells. However, its potential mechanism in inducing autophagy is still under our investigation. Here, data from our western blotting assays showed that, in NSCLC cells, (-)-Guaiol significantly blocked the mTORC2-AKT signaling by suppressing mTOR phosphorylation at serine 2481 (S2481) to induce autophagy, illustrated by the increasing ratio of LC3II/I. Besides, it impaired the mTORC1 signaling by inhibiting the activity of its downstream factors, such as 4E-BP1 and p70 S6K, all of which could obviously rescued by the mTOR activator MHY1485. Afterwards, results from biofunctional assays, including cell survival analysis, colony formation assays and flow cytometry assays, suggested that (-)-Guaiol triggered autophagic cell death by targeting both mTORC1 and mTORC2 signaling pathways. In summary, our studies showed that (-)-Guaiol inhibited the proliferation of NSCLC cells by specifically targeting mTOR signaling pathways, including both mTORC1 and mTORC2 signaling, providing a better therapeutic option for substituting rapamycin in treating NSCLC patients.

(-)-Guaiol regulates RAD51 stability via autophagy to induce cell apoptosis in non-small cell lung cancer.

(-)-Guaiol, generally known as an antibacterial compound, has been found in many medicinal plants. Its roles in tumor suppression are still under investigation. In the study, we mainly focused on exploring its applications in dealing with non-small cell lung cancer (NSCLC) and the underlying mechanisms. Here, we show that (-)-Guaiol significantly inhibits cell growth of NSCLC cells both in vitro and in vivo. Further high throughput analysis reveals that RAD51, a pivotal factor in homologous recombination repair, is a potential target for it. The following mechanism studies show that (-)-Guaiol is involved in cell autophagy to regulate the expression of RAD51, leading to double-strand breaks triggered cell apoptosis. Moreover, targeting RAD51, which is highly overexpressed in the lung adenocarcinoma tissues, can significantly increase the chemosensitivity of NSCLC cells to (-)-Guaiol both in vitro and in vivo. All in all, our studies provide an attractive insight in applying (-)-Guaiol into NSCLC treatments and further suggest that knockdown of oncogenic RAD51 will greatly enhance the chemosensitivity of patients with NSCLC.

A Randomized Clinical Trial of Berberine Hydrochloride in Patients with Diarrhea-Predominant Irritable Bowel Syndrome.

We aimed to evaluate clinical symptoms in diarrhea predominant irritable bowel syndrome (IBS-D) receiving berberine hydrochloride in a randomized double-blind placebo-controlled clinical trial. Overall, 196 patients with IBS-D were recruited for this study; consequently, 132 patients randomized to receive daily 400 mg of berberine hydrochloride, delivered twice daily or placebo for 8 weeks followed by a 4-week washout period. After a 2-week run-in period, diarrhea, abdominal pain, urgent need for defecation frequency and any adverse events were recorded daily. Prior to administration of the medication and after completing the treatment, assessment of IBS symptom scores, depression and anxiety scale scores and the IBS scale for quality of life (QOL) was carried out. The effects of berberine hydrochloride on IBS-D, defined by a reduction of diarrhea frequency (P = 0.032), abdominal pain frequency (P < 0.01) and urgent need for defecation frequency (P < 0.01), were significantly more pronounced in the berberine group than the placebo group in the 8 weeks of treatment. A trend of improvement (P < 0.05) was observed with berberine hydrochloride for IBS symptom score, depression score and anxiety score and the IBSQOL, compared with placebo. At last, berberine hydrochloride was well tolerated. So we concluded that berberine hydrochloride is well tolerated and reduces IBS-D symptoms, which effectively improved patients QOL.