Oligonol, a Low Molecular Weight Polyphenol, Enhances Apoptotic Cell Death in Ovarian Cancer Cells via Suppressing NF-κB Activation

Low-molecular-weight polyphenol promotes cell sensitivity to cisplatin and alleviates cancer-related muscle atrophy via NF-κB suppression in oral squamous cell carcinoma

OBJECTIVE

Drug resistance and subsequent adverse effects, such as cancer cachexia, limit the clinical use of cisplatin. Oligonol® (Olg), a low-molecular-weight polyphenol, exhibits NF-κB inhibitory properties. NF-κB activation has been implicated in cisplatin resistance of cancer cells and skeletal muscle wasting. Therefore, we hypothesized that combined cisplatin and Olg could overcome chemoresistance and reduce muscle atrophy.

METHODS

To investigate the efficiency of Olg, oral squamous cell carcinoma (OSCC) cells were used for chemosensitivity, and human skeletal muscle myoblast (HSkMC) was used for muscle atrophy. HSkMCs treated with OSCC cell-derived conditioned medium were used to examine the role of Olg in muscle atrophy mediated by the tumor inflammatory microenvironment.

RESULTS

Olg exerted little effect on the viability of OSCC cells by promoting apoptotic cell death. However, it exhibited excellent capability to enhance the sensitivity of OSCC cells to cisplatin and overcome the acquired cisplatin resistance of OSCC. We revealed that NF-κB signaling contributes to cisplatin resistance in OSCC cells, whereas Olg enhances cell sensitivity to cisplatin by NF-κB suppression. Conversely, Olg contributes to a positive protein turnover and alleviates cisplatin-induced muscle atrophy by regulating Akt/mTOR/p70S6K and NF-κB/MuRF1 pathway. Olg represses TNF-α and interleukin 6 driven from OSCC cells and alleviates muscle atrophy mediated by the tumor inflammatory microenvironment.

CONCLUSIONS

Olg enhanced cisplatin chemosensitivity and reduced its adverse effects on skeletal muscle, suggesting its potential as a chemosensitizing agent for cisplatin. Further animal and clinical studies are required to validate these findings.

Treatment with autophagic inhibitors enhances oligonol‑induced apoptotic effects in nasopharyngeal carcinoma cells

Although the combination of chemotherapy and radiotherapy has increased the survival rate of patients with nasopharyngeal carcinoma (NPC), certain patients do not respond well to the treatment and have a poor prognosis. Therefore, novel therapeutic drugs and strategies to improve prognosis of patients with NPC are required. As certain plant extracts can suppress the viability of cancer cells, the present study investigated whether oligonol, a polyphenolic compound primarily found in lychee fruit, exerts anticancer activities in NPC cells. MTT, ELISA and immunoblotting were performed to investigate cell survival, cytokeratin-18 fragment release, and the expression of apoptosis and autophagy markers, respectively. Oligonol decreased the viability of NPC-TW01 and NPC/HK1NPC cell lines. Oligonol increased the protein expression of several apoptosis markers, including cleaved caspase-8 and -3, cleaved PARP and cytokeratin 18 fragment. Moreover, it also increased expression of autophagy markers Beclin 1 and LC3-II, as well as LC3-II/LC3-I ratio in both NPC cell lines. Furthermore, treatment with autophagy inhibitors 3-methyladenine or LY294002 significantly increased oligonol-induced viability inhibition in NPC-TW01 cells. Combined treatment of oligonol + LY294002 reduced LC3-II expression and the LC3II/LC3I ratio while increasing cleaved caspase-8 and -3, cleaved PARP and cytokeratin 18 fragment expression in NPC-TW01 cells. These findings indicated autophagy inhibitors could enhance viability inhibition and apoptotic effects induced by oligonol in NPC cells.

Integrative Transcriptomic Analysis Reveals Upregulated Apoptotic Signaling in Wound-Healing Pathway in Rat Liver Fibrosis Models

Liver fibrosis, defined by the aberrant accumulation of extracellular matrix proteins in liver tissue due to chronic inflammation, represents a pressing global health issue. In this study, we investigated the transcriptomic signatures of three independent liver fibrosis models induced by bile duct ligation, carbon tetrachloride, and dimethylnitrosamine (DMN) to unravel the pathological mechanisms underlying hepatic fibrosis. We observed significant changes in gene expression linked to key characteristics of liver fibrosis, with a distinctive correlation to the burn-wound-healing pathway. Building on these transcriptomic insights, we further probed the p53 signaling pathways within the DMN-induced rat liver fibrosis model, utilizing western blot analysis. We observed a pronounced elevation in p53 protein levels and heightened ratios of BAX/BCL2, cleaved/pro-CASPASE-3, and cleaved/full length-PARP in the livers of DMN-exposed rats. Furthermore, we discovered that orally administering oligonol-a polyphenol, derived from lychee, with anti-oxidative properties-effectively countered the overexpressions of pivotal apoptotic genes within these fibrotic models. In conclusion, our findings offer an in-depth understanding of the molecular alterations contributing to liver fibrosis, spotlighting the essential role of the apoptosis pathway tied to the burn-wound-healing process. Most importantly, our research proposes that regulating this pathway, specifically the balance of apoptosis, could serve as a potential therapeutic approach for treating liver fibrosis.

HSP60 Regulates Lipid Metabolism in Human Ovarian Cancer

Accumulating evidence demonstrates that cancer is an oxidative stress-related disease, and oxidative stress is closely linked with heat shock proteins (HSPs). Lipid oxidative stress is derived from lipid metabolism dysregulation that is closely associated with the development and progression of malignancies. This study sought to investigate regulatory roles of HSPs in fatty acid metabolism abnormality in ovarian cancer. Pathway network analysis of 5115 mitochondrial expressed proteins in ovarian cancer revealed various lipid metabolism pathway alterations, including fatty acid degradation, fatty acid metabolism, butanoate metabolism, and propanoate metabolism. HSP60 regulated the expressions of lipid metabolism proteins in these lipid metabolism pathways, including ADH5, ECHS1, EHHADH, HIBCH, SREBP1, ACC1, and ALDH2. Further, interfering HSP60 expression inhibited migration, proliferation, and cell cycle and induced apoptosis of ovarian cancer cells in vitro. In addition, mitochondrial phosphoproteomics and immunoprecipitation-western blot experiments identified and confirmed that phosphorylation occurred at residue Ser70 in protein HSP60, which might regulate protein folding of ALDH2 and ACADS in ovarian cancers. These findings clearly demonstrated that lipid metabolism abnormality occurred in oxidative stress-related ovarian cancer and that HSP60 and its phosphorylation might regulate this lipid metabolism abnormality in ovarian cancer. It opens a novel vision in the lipid metabolism reprogramming in human ovarian cancer.