Enhanced anticancer activity by the combination of vinpocetine and sorafenib via PI3K/AKT/GSK-3ß signaling axis in hepatocellular carcinoma cells.

Vinpocetine is widely used to treat cerebrovascular diseases. However, the effect of vinpocetine to treat hepatocellular carcinoma (HCC) has not been investigated. In this study, we revealed that vinpocetine was associated with antiproliferative activity in HCC cells, but induced cytoprotective autophagy, which restricted its antitumor activity. Autophagy inhibitors improved the antiproliferative activity of vinpocetine in HCC cells. Sorafenib is effective to treat advanced HCC, but the effect of autophagy induced by sorafenib is indistinct. We demonstrated vinpocetine plus sorafenib suppressed the cytoprotective autophagy activated by vinpocetine in HCC cells and significantly induced apoptosis and suppressed cell proliferation in HCC cells. In addition, vinpocetine plus sorafenib activates glycogen synthase kinase 3ß (GSK-3ß) and subsequently inhibits cytoprotective autophagy induced by vinpocetine in HCC cells. Meanwhile, overexpression of GSK-3ß was efficient to increase the apoptosis induced by vinpocetine plus sorafenib in HCC cells. Our study revealed that vinpocetine plus sorafenib could suppress the cytoprotective autophagy induced by vinpocetine and subsequently show synergistically anti-HCC activity via activating GSK-3ß and the combination of vinpocetine and sorafenib might reverse sorafenib resistance via the PI3K/protein kinase B/GSK-3ß signaling axis. Thus, vinpocetine may be a potential candidate for sorafenib sensitization and HCC treatment, and our results may help to elucidate more effective therapeutic options for HCC patients with sorafenib resistance.

A natural anthraquinone derivative shikonin synergizes with AZD9291 against wtEGFR NSCLC cells through reactive oxygen species-mediated endoplasmic reticulum stress.

BACKGROUND: NSCLC is the major type of lung cancer and the survival rates of NSCLC patients remain low. AZD9291 is a third-generation EGFR-TKI and approved to treat NSCLC patients harboring EGFR T790M mutation and common targetable activating EGFR mutations, but it has a limited effect for wtEGFR NSCLC. PURPOSE: The current study investigated whether shikonin could enhance the antitumor effect of AZD9291 in wtEGFR NSCLC cells. METHODS: SRB and colony formation assay were used to detect the proliferation of NSCLC cells, propidium iodide staining was performed to detect the apoptosis, ROS was analyzed using DCFH-DA staining, and western blot was used to detect the expression of indicated proteins. RESULTS: We demonstrated that shikonin, a natural ROS inducer, could enhance the antitumor effect of AZD9291 in wtEGFR NSCLC cells. In addition, shikonin increased AZD9291-induced apoptosis accompanying with the generation of ROS and activation of ER stress. Furthermore, ROS inhibition by NAC or GSH reversed the apoptosis induced by shikonin plus AZD9291, and recovered the ER stress activated by combination treatment, indicating that ROS mediated ER stress played a vital role in this combination therapy. Moreover, shikonin increased the anticancer activity of AZD9291 in primary wtEGFR NSCLC cells through ROS-mediated ER stress. CONCLUSION: Our study suggests that combining shikonin with AZD9291 is a promising therapeutic strategy for treating wtEGFR NSCLC patients.

Harmine suppresses the proliferation of pancreatic cancer cells and sensitizes pancreatic cancer to gemcitabine treatment.

PURPOSE: Pancreatic carcinoma is one of the most deadliest types of cancer, and relatively insensitive to the currently available chemotherapy. Thus, the discovery of novel therapeutic agents to prolong the survival times of patients with pancreatic cancer is urgently required. METHODS: Cell proliferation was assessed using the sulforhodamine B and cell clone formation assay, apoptosis was analyzed through Annexin V/PI staining, analysis of cell cycle distribution was determined by PI staining, and the expression of proteins was detected via Western blotting. RESULTS: Our data showed that harmine exerted an anti-proliferative effect and cell cycle arrest at G2/M in pancreatic cancer cells. Meanwhile, harmine plus gemcitabine showed strong synergy in inhibiting the proliferation of pancreatic cancer cells. Furthermore, harmine induced apoptosis and enhanced the gemcitabine-induced apoptosis in pancreatic cancer cells. The AKT/mTOR pathway is involved in mechanisms of gemcitabine resistance in pancreatic cancer cells, our data demonstrated that harmine plus gemcitabine significantly suppressed the AKT/mTOR signaling pathway. CONCLUSION: Harmine may be a potential candidate for the treatment of pancreatic cancer. Morever, the combination of harmine with gemcitabine appears to be an attractive option for the treatment of patients with pancreatic cancer.

Suppression of LSD1 enhances the cytotoxic and apoptotic effects of regorafenib in hepatocellular carcinoma cells.

Regorafenib has been approved to treat patients who have HCC progression after sorafenib failure, however, regorafenib also faces the risk of drug resistance and subsequent progression of HCC patients. As LSD1 inhibitors can alleviate acquired resistance to sorafenib, in this context, we are interested to investigate the role of LSD1 in regorafenib treatment. Firstly, over-expressed LSD1 was observed in HCC patients and predicted poor prognosis. However, regorafenib failed to suppress the expression of LSD1 in HCC cells. Thus, we hypothesized that LSD1 inhibition could enhance the anti-HCC activity of regorafenib. As expected, LSD1 knockdown could enhance anti-proliferation effect of regorafenib in HCC cells. LSD1 inhibitor SP2509 could enhance the cytotoxic and apoptotic effects of regorafenib in HCC cells. In addition, clinically used LSD1 inhibitor tranylcypromine also enhanced anti-HCC effect of regorafenib. Furthermore, LSD1 suppressed by SP2590 or tranylcypromine could alleviate the activated p-AKT (ser473) induced by regorafenib in HCC cells. Thus, inhibiting LSD1 might be an attractive target for regorafenib sensitization and clinical HCC therapy, our findings could help to elucidate more effective therapeutic options for HCC patients.

Association between PDE4D rs966221 polymorphism and risk of ischemic stroke: a systematic review and meta-analysis.

PDE4D polymorphism (SNP83/rs966221) was reported to be associated with the susceptibility to ischemic stroke (IS), however, the results were inconclusive. An electronic search of Embase, PubMed, CNKI and Wan Fang Date was performed to identify relevant studies published throughout April 2017. A total of 26 studies were enrolled in the analysis. No significant association between the rs9662221 polymorphism and IS was observed in the overall analysis. Nevertheless, in the subgroup analysis, our results showed a significant association between the SNP83 polymorphism and IS in CC+ CT vs. TT (OR = 1.19, 95% CI: 1.02-1.38), CT vs.TT (OR = 1.14, 95% CI: 1.01-1.29) and C vs. T (OR = 1.25, 95% CI: 1.06-1.48) in Asian population. But we did not found any association in CC vs. CT + TT (OR = 1.2, 95% CI: 0.9-1.61) and CC vs. TT (OR = 1.26, 95% CI: 0.91-1.75) in the Asian populations. Meantime, no significant correlations were observed under the five genetic model in Caucasian population (p > 0.05). In conclusion, our meta-analysis demonstrated that the SNP83 polymorphism in the PDE4D gene might contribute to IS susceptibility especially in Asian populations. Whereas the relationship of the polymorphism to the disease in Caucasian population was still in controversial. In future, additional well designed studies with larger sample sizes are still required to further elucidate this association.

A facile chemoenzymatic approach: one-step syntheses of monoterpenoid indole alkaloids.

Facile chemoenzymatic syntheses of cytotoxic monoterpenoid indole alkaloids with novel skeletons and multiple chiral centers are described. Synthesis of these alkaloids was achieved by a simple one-step reaction using strictosidine and 12-aza-strictosidine as the key intermediates. Strictosidines were prepared by coupling of secologanin with tryptamine and 7-aza-tryptamine, respectively, using the immobilized recombinant Rauvolfia strictosidine synthase. A detailed stereochemical analysis is presented herein. The results provide an opportunity for a chemoenzymatic approach that leads to an increased diversification of complex alkaloids with improved structures and activities.