Oral cancer is one of the most common cancers in the world. Approximately 90% of oral cancers are subtyped to oral squamous cell carcinoma (OSCC). Despite advances in diagnostic techniques and improvement in treatment modalities, the prognosis remains poor. Therefore, an effective chemotherapy mechanism that enhances tumor sensitivity to chemotherapeutics is urgently needed. Methyl protodioscin (MP) is a furostanol bisglycoside with a wide range of beneficial effects, including anti-inflammatory and anti-cancer properties. The aim of the present study was to determine the antitumor activity of MP on OSCC and its underlying mechanisms. Our results show that treatment of OSCC cells with MP potently inhibited cell viability. Moreover, MP leading to cell cycle arrest at G2/M phase, which subsequently activates caspase-3, -8, -9 and PARP to induce cell apoptosis. Meanwhile, we also demonstrate that MP induces a robust autophagy in OSCC cells. The results indicate cathepsin S (CTSS) is involved in MP-induced apoptosis and autophagy by modulation of p38 MAPK and JNK1/2 pathways. These findings may provide rationale to combine MP with CTSS blockade for the effective treatment of OSCC.

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Nasopharyngeal carcinoma (NPC) is an important issue in Asia because of its unique geographical and ethnic distribution. Cisplatin-based regimens are commonly the first-line used chemotherapy, but resistance and toxicities remain a problem. Therefore, the use of anticancer agents derived from natural products may be a solution. Asiatic acid (AA), extracted from Centella asiatica, was found to have anticancer activity in various cancers. The aim of this study is to examine the cytotoxic effect and mediated mechanism of AA in cisplatin-resistant NPC cells. The results shows that AA significantly reduce the cell viability of cisplatin-resistant NPC cell lines (cis NPC-039 and cis NPC-BM) in dose and time dependent manners caused by apoptosis through the both intrinsic and extrinsic apoptotic pathways, including altered mitochondrial membrane potential, activated death receptors, increased Bax expression, and upregulated caspase 3, 8, and 9. The Western blot analysis of AA-treated cell lines reveals that the phosphorylation of MAPK pathway proteins is involved. Further, the results of adding inhibitors of these proteins indicates that the phosphorylation of p38 are the key mediators in AA-induced apoptosis in cisplatin-resistant human NPC cells. This is the first study to demonstrate the AA-induced apoptotic pathway through the phosphorylation p38 in human cisplatin-resistant nasopharyngeal carcinoma. AA is expected to be another therapeutic option for cisplatin-resistant NPC because of the promising anti-cancer effect and fewer toxic properties.

Background/Aims: Cancer is the most common cause of death worldwide with approximately one third of people being diagnosed with cancer in their lifetime. Pinostilbene hydrate (PSH) A methylated derivative of resveratrol Has been reported to possess antioxidative Cardioprotective and anticancer properties. However the antimetastatic effect of pinostilbene in oral squamous cell carcinoma (OSCC) remains unknown. Methods: In this study We investigated the effect of PSH on antimetastatic activity and the relevant signaling pathways underlying mechanisms of SCC-9 SAS and HSC-3 oral cancer cell lines by MTT assay Wound healing Transwell assay Zymography and western blot analysis. Results: Our findings indicated that PSH inhibits migration and invasion ability by reducing the protein activity and expression of matrix metalloproteinases-2 (MMP-2) in all three cell lines. Moreover • The phosphorylation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinases (p38) had significant inhibitory effects in the presence of PSH in the SCC9 and SAS cell lines. A combination of ERK1/2 and p38 inhibitors with PSH also reduced the migration and activity of MMP-2 in the SCC9 and SAS cell lines. Conclusion: This study demonstrated that PSH suppresses MMP-2 enzymatic activity by downregulating the p38/ERK1/2 pathway and that it might be a promising agent for preventing OSCC cell metastasis.

Nasopharyngeal carcinoma (NPC) is an unnoticeable malignant tumor with a high potential of lymphatic metastasis, and its prevalence is high in Asia. Ionizing radiation is the mainstay of treatment for patients with NPC without metastasis. However, patients with metastatic lesions require advanced treatments such as chemotherapy. The present study investigated the apoptotic effect of luteolin‐7‐O‐glucoside on NPC cells and elucidated its underlying signaling mechanisms. The results revealed that luteolin‐7‐O‐glucoside significantly reduced the proliferation of NPC cell lines (NPC‐039 and NPC‐BM). Flow cytometry and morphological analysis results demonstrated that luteolin‐7‐O‐glucoside treatment induced S and G2/M cell cycle arrest, chromatin condensation, and apoptosis. In addition, mitochondrial membrane potential was observed to be depolarized with an increasing concentration of luteolin‐7‐O‐glucoside. Proteins involved in the extrinsic and intrinsic pathways of apoptosis, such as death receptor, caspase‐3, caspase‐8, caspase‐9, and Bcl‐2 family proteins (Bax, t‐Bid, Bcl‐2, and Bcl‐xL), were downregulated and upregulated after treatment with luteolin‐7‐O‐glucoside, respectively. Moreover, the addition of a PI3K/AKT inhibitor enhanced the activation of poly‐ADP‐ribose‐polymerase (PARP) and attenuated cell viability, indicating that luteolin‐7‐O‐glucoside induced apoptosis in NPC cells through the AKT signaling pathway. These results indicated that the apoptosis of NPC cells modulated by luteolin‐7‐O‐glucoside may be preceded by mitochondrial depolarization, cell cycle arrest, extrinsic and intrinsic apoptosis pathway activation, and AKT signaling modulation. Thus, luteolin‐7‐O‐glucoside can be a promising anticancer agent against human NPC.