Proteomic Analysis Reveals that Odoroside A Triggers G2/M Arrest and Apoptosis in Colorectal Carcinoma Through ROS-p53 Pathway.

Odoroside A (OA) is an active ingredient extracted from the leaves of Nerium oleander Linn. (Apocynaceae). This study aims to examine the anticancer bioactivity of OA against CRC cells and to investigate the action mechanisms involved. As a result, OA can significantly inhibit cellular ability and induce apoptosis of CRC cells in a concentration-dependent manner without any obvious cytotoxicity in normal colorectal epithelial cells. Then, quantitative proteomics combined with bioinformatics is adopted to investigate the alterations of proteins and signaling pathways in response to OA treatment. As suggested by the proteomic analysis, flow cytometry and Western blotting analyses validate that exposure of CRC cells to OA causes cell cycle arrest and apoptosis, accompanied with the activation of the ROS/p53 signaling pathway. This observation demonstrates that OA, as a natural product, can induce oxidative stress to suppress tumor cell growth, implicating a novel therapeutic agent against CRC without obvious side effects.

ANO1 Reprograms Cholesterol Metabolism and the Tumor Microenvironment to Promote Cancer Metastasis.

SIGNIFICANCE: Metastatic cancer cells upregulate ANO1 to activate cell-intrinsic and -extrinsic mechanisms that alter cholesterol metabolism and stimulate fibroblasts, which can be targeted with ANO1 inhibitors to inhibit metastatic growth. See related commentary by Singh and Mehla, p. 1759.

Lysine 2-hydroxyisobutyrylation of NAT10 promotes cancer metastasis in an ac4C-dependent manner.

Posttranslational modifications add tremendous complexity to proteomes; however, gaps remain in knowledge regarding the function and regulatory mechanism of newly discovered lysine acylation modifications. Here, we compared a panel of non-histone lysine acylation patterns in metastasis models and clinical samples, and focused on 2-hydroxyisobutyrylation (Khib) due to its significant upregulation in cancer metastases. By the integration of systemic Khib proteome profiling in 20 paired primary esophageal tumor and metastatic tumor tissues with CRISPR/Cas9 functional screening, we identified N-acetyltransferase 10 (NAT10) as a substrate for Khib modification. We further showed that Khib modification at lysine 823 in NAT10 functionally contribute to metastasis. Mechanistically, NAT10 Khib modification enhances its interaction with deubiquitinase USP39, resulting in increased NAT10 protein stability. NAT10 in turn promotes metastasis by increasing NOTCH3 mRNA stability in an N4-acetylcytidine-dependent manner. Furthermore, we discovered a lead compound #7586-3507 that inhibited NAT10 Khib modification and showed efficacy in tumor models in vivo at a low concentration. Together, our findings bridge newly identified lysine acylation modifications with RNA modifications, thus providing novel insights into epigenetic regulation in human cancer. We propose that pharmacological inhibition of NAT10 K823 Khib modification constitutes a potential anti-metastasis strategy.

Nerigoside suppresses colorectal cancer cell growth and metastatic potential through inhibition of ERK/GSK3ß/ß-catenin signaling pathway.

BACKGROUND: Nerigoside (NG), a cardenolide isolated from a commonfolk medicine, Nerium oleander Linn. (Apocynaceae), has not been explored for its biological effects. To date, cardenolides have received considerable attention in pharmacology studies due to their direct effects of apoptosis-induction or growth-inhibitory against tumor in vitro and in vivo. Whether and how NG exerts anticancer effects against colorectal cancer remains to be elucidated. PURPOSE: The aim of this study was to investigate the anticancer effect of NG in human colorectal cancer cells. METHODS: To test anticancer effect, we compared potency of NG in two colorectal cancer cell lines, HT29 and SW620 by WST-1 and colony proliferation assays. And we investigated mechanism of anticancer activities by analyzing players in apoptotic and ERK/GSK3ß/ß-catenin signaling pathways in HT29 and SW620 cells treated with NG. RESULTS: In this study, we showed that NG markedly suppressed the cell viability and colony formation of colorectal cancer cells HT29 and SW620, with no significant toxic effect on non-cancer cells NCM460. Annexin V-FITC/PI and CFSE labeling results revealed that NG suppressed cell proliferation in low concentration, along with reducing expression of PCNA, while NG induced apoptosis in high concentration,. Meanwhile, NG significantly arrested cell migration by reversal of EMT and cell cycle on G2/M. Then, we found that the ERK and GSK3ß/ß-catenin signaling pathway were noticeably blocked in CRC cells after treatment with NG. According to western blot, NG upregulated the expression of p-GSK3ß/GSK3ß and decreased especially the expression of ß-catenin in nuclear. In addition, Wnt signaling and its target genes were suppressed in response to NG. Then, the Ser9 phosphorylation of GSK3ß can be reduced / raised by GÖ 6983 / LiCl, respectively. Thus, we further confirmed that the GSK3ß/ß-catenin axis is involved in NG-prevented cell proliferation. CONCLUSION: NG inhibited the growth of colorectal cancer cells by suppressing ERK/GSK3ß/ß-catenin signaling pathway. And the GSK3ß/ß-catenin axis is involved in preventing cell proliferation and migration by NG-treatment. These results suggest that NG may be used to treat colorectal cancer, with better outcome by combining with GSK3ß inhibitor to block Wnt pathway.