Curcumin protect Schwann cells from inflammation response and apoptosis induced by high glucose through the NF-κB pathway.

Demyelination disease as diabetes mellitus (DM) complication is characterized by apoptosis of Schwann cells (SCs) and several reports have demonstrated that high glucose content can induce an inflammation response and lead to the apoptosis of SCs. For NF-κB plays a pivotal role in the inflammatory response, hence we hypothesized that high glucose content can induce inflammation though the NF-κB pathway. First we verified that 150 mM high glucose can increase the expression of cleaved caspase 3, interleukin (IL)- 1ß, Cyto-C and NF-κB with time through Western blot and increase the apoptosis of RSC96s through Flow Cytometry. Then we found that high glucose can increase the nuclear translocation NF-κB through confocal system which can promote the expression of inflammation genes such as IL-1ß. Curcumin has been reported to possess anti-inflammation activities to protect cells. In this study, we found that application with 25 µM curcumin could alleviate the inflammation response and protect the cells from apoptosis. We revealed that the expression of NF-κB and p-NF-κB was decreased and the translocation was also inhibited after curcumin application. Accordingly, the secretion of IL-1ß and the apoptosis of RSC96s induce by high glucose was suppressed. Our cumulative findings suggest that curcumin can protect SCs from apoptosis through the inhibition of the inflammatory response though the NF-κB pathway.

Gambogenic acid inhibits fibroblast growth factor receptor signaling pathway in erlotinib-resistant non-small-cell lung cancer and suppresses patient-derived xenograft growth.

Erlotinib resistance causes a high degree of lethality in non-small-cell lung cancer (NSCLC) patients. The high expression and activation of several receptor tyrosine kinases, such as JAK/STAT3, c-Met, and EGFR, play important roles in drug resistance. The development of tyrosine kinase inhibitors is urgently required in the clinic. Our previous study found that Gambogenic acid (GNA), a small molecule derived from the traditional Chinese medicine herb gamboge, induced cell death in several NSCLC cell lines through JAK/STAT3 inhibition. In this study, we investigated the mechanism of action of GNA in erlotinib-resistant NSCLC and patient-derived cells. The inhibition of GNA on FGFR signaling pathway was examined using biochemical kinase assays. NSCLC cell lines (HCC827, HCC827-Erlotinib-resistant, and H1650) and primary cells from patients with NSCLC with clinical resistance to erlotinib were treated with GNA, erlotinib, or their combination. Both kinase assays and cell- based assays showed that GNA inhibits the phosphorylation of multiple kinases in FGFR signaling pathway in NSCLC. The combination of GNA and erlotinib significantly attenuates the tumor growth of HCC827 and erlotinib-resistant HCC827 xenografts with low toxicity. Importantly, GNA significantly suppresses tumor growth in a lung patient-derived xenograft (PDX) model with FGFR fusion and low EGFR expression. Our findings provide preclinical evidence for using GNA as an FGFR signaling pathway inhibitor to overcome erlotinib resistance in NSCLC treatment or to enhance erlotinib efficacy when used as a combined administration.

Ubiquitin-conjugating enzyme UbcH10 promotes gastric cancer growth and is a potential biomarker for gastric cancer.

Gastric cancer is a fatal disease and the availability of early diagnostic methods is limited. There is an urgent need to identify effective targets for early diagnosis and therapeutics. UbcH10 is a ubiquitin-conjugating enzyme with high expression in various types of cancers. In the present study, several gastric tumor cell lines with high or low expression of UbcH10 were exploited to study the role of UbcH10 in gastric cancer. Knockdown of UbcH10 expression using siRNA in gastric cancer cell lines with high expression of UbcH10 resulted in reduced proliferation, increased cisplatin-induced apoptosis and reduced serum-induced ERK, Akt and p38 phosphorylation signaling. In agreement, overexpression of UbcH10 in gastric cancer cell lines with low expression of UbcH10 led to enhanced cell proliferation and resistance to cisplatin-induced apoptosis. Most importantly, IHC analyses showed that the UbcH10 protein was expressed at a high level in most patient gastric cancer tissues, but was absent in adjacent mesenchyme tissues. These data suggest that UbcH10 may promote gastric cancer growth and can serve as a biomarker for diagnosis or as a target for novel therapeutics in gastric cancer.