Decreased expression of mitochondrial miR-5787 contributes to chemoresistance by reprogramming glucose metabolism and inhibiting MT-CO3 translation.

MicroRNAs (miRNAs) have been recently found in the mitochondria, and were named "mitomiRs", but their function has remained elusive. Here, we aimed to assess the presence and function(s) of mitomiRs in tongue squamous cell carcinoma (TSCC). Methods: miRNA microarray was performed in paired TSCC cell lines, Cal27 and its chemoresistant counterpart, Cal27-re. Decreased expression of mitomiRs in chemoresistant cells was characterized. The functions of mitomiRs were investigated by a series of in vitro and in vivo experiments. Results: Differential microarray analysis identified downregulation of mitomiR-5787 in Cal27-re cells. We knocked down mitomiR-5787 in parental cells and upregulated its expression in cisplatin-resistant cells. The sensitivity of TSCC cells to cisplatin was regulated by miR-5787. The glucose metabolism assay suggested that reduced expression of miR-5787 changed the balance of glucose metabolism by shifting it from oxidative phosphorylation to aerobic glycolysis. Xenograft experiments in BALB/c-nu mice further verified the in vitro results. Reduced expression of miR-5787 contributes to chemoresistance in TSCC cells by inhibiting the translation of mitochondrial cytochrome c oxidase subunit 3 (MT-CO3). The prognostic analysis of 126 TSCC patients showed that the patients with low expression of miR-5787 and/or MT-CO3 had poor cisplatin sensitivity and prognosis. Conclusions: Mitochondrial miR-5787 could regulate cisplatin resistance of TSCC cells and affect oxidative phosphorylation and aerobic glycolysis. Downregulation of miR-5787 inhibited the translation of MT-CO3 to regulate cisplatin resistance of TSCC. Mitochondrial miR-5787 and MT-CO3 can be used as predictive biomarkers or therapeutic targets for cisplatin chemotherapy resistance.

Cancer-associated fibroblasts confer cisplatin resistance of tongue cancer via autophagy activation.

Cancer-associated fibroblasts (CAFs) play important roles in carcinogenesis and progression of tongue squamous cell carcinoma (TSCC). However, effect of CAFs on chemotherapy resistance of TSCC remains largely obscure. Here, we cultured the matched primary CAFs and normal fibroblasts (NFs) pairs and detected their roles in cisplatin sensitivity of TSCC, as well as autophagy-related protein LC3 and Beclin1 expressions. During exposure to cisplatin, TSCC with CAFs group exhibited significantly increased cell viability and IC50, but reduced apoptosis than that with NFs group. Meanwhile, cisplatin increased the LC3-II and Beclin1 levels of those TSCC co-cultured with CAFs. Activation of cisplatin-induced autophagic flux was inhibited by CQ, which can accumulate LC3-II protein and increase punctate distribution of LC3 localization. Beclin1 siRNA also decreased the cisplatin-induced autophagy. Both CQ and Beclin1 siRNA increased cisplatin-induced apoptosis but inhibited viability of TSCC co-cultured with CAFs. In vivo, combination of cisplatin and CQ significantly inhibited the growth of xenografted tumors than cisplatin alone. Taken together, our findings highlight the important role of CAFs in cisplatin resistance of tongue cancer via autophagy activation, suggesting that inhibition of autophagy could be an optimal strategy for chemoresistance of TSCC.

IncRNA H19 promotes tongue squamous cell carcinoma progression through ß-catenin/GSK3ß/EMT signaling via association with EZH2.

H19 is involved in tumor metastasis and associated with tumor progression. Enhancer of zest homolog 2 (EZH2) is overexpressed in multiple cancer types and correlates with tumor proliferation, epithelial-mesenchymal transition, and poor prognosis. However, the interaction between H19 and EZH2 to promote tongue squamous cell carcinoma (TSCC) progression remains largely uncharacterized. Insitu hybridization and quantitative reverse-transcription PCR (qRT-PCR) were performed to measure H19 expression in primary TSCC and adjacent normal tissues and cell lines. EZH2 expression was determined by immunohistochemistry in matched primary TSCC and adjacent normal tissues. The correlation between H19 and EZH2 expression and clinicopathological characteristics were analyzed. The roles of H19 in cell proliferation, apoptosis, and invasion were analyzed using a H19-targeted lentivirus. Western blot and qRT-PCR were carried out to detect downstream signal pathway changes. Expression levels of downstream signaling proteins in primary TSCC tissues and adjacent normal tissues were analyzed by immunohistochemistry. H19 and EZH2 were upregulated in TSCC tissues compared to matched normal tissues, and significantly correlated with WHO grade, lymph node metastasis, and poor prognosis. H19 silencing attenuated cell proliferation, apoptosis, and invasion in vitro. H19 knockdown inhibited the activation of ß-catenin/GSK-3ß/cyclin D1/c-myc, upregulated E-cadherin and zonula occludens-1 (ZO-1), and inhibited N-cadherin, vimentin, Snail1, Twist1, and ZEB1. Silencing H19 expression also inhibited tumor progression and lung metastasis in an animal model. Our findings indicate that H19 promotes TSCC progression through association with EZH2, and affects downstream ß-Catenin/GSK3ß/EMT signaling, suggesting that H19 inhibition might be a potential target for the treatment of TSCC.

Intrahepatic cholangiocarcinoma prognostic determination using pre-operative serum C-reactive protein levels.

BACKGROUND: Serum C-reactive protein (CRP), an acute inflammatory response biomarker, has been recognized as an indicator of malignant disease progression. However, the prognostic significance of CRP levels collected before tumor removal in intrahepatic cholangiocarcinoma requires further investigation. METHODS: We sampled the CRP levels in 140 patients with intrahepatic cholangiocarcinoma who underwent hepatectomies with regional lymphadenectomies between 2006 and 2013. A retrospective analysis of the clinicopathological data was performed. We focused on the impact of serum CRP on the patients' cancer-specific survival and recurrence-free survival rates. RESULTS: High levels of preoperative serum CRP were significantly associated with well-established clinicopathologic features, including gender, advanced tumor stage, and elevated carcinoembryonic antigen and carbohydrate antigen 19-9 levels (P < 0.05). Univariate analysis demonstrated a significant association between high levels of serum CRP and adverse cancer-specific survival (P = 0.001) and recurrence-free survival (P < 0.001). In patients with stage I/II intrahepatic cholangiocarcinoma, the serum CRP level was a prognostic indicator for cancer-specific survival. In patients with stage I/II or stage III/IV, the serum CRP level was a prognostic indicator for recurrence-free survival (P < 0.05). Additionally, multivariate analysis identified serum CRP level in intrahepatic cholangiocarcinoma as an independent prognostic factor (P < 0.05). CONCLUSIONS: We confirmed a significant association of elevated pre-operative CRP levels with poor clinical outcomes for the tested patients with intrahepatic cholangiocarcinoma. Our results indicate that the serum CRP level may represent a useful factor for patient stratification in intrahepatic cholangiocarcinoma management.

Role of Negative-Pressure Wound Therapy in the Management of Submandibular Fistula After Reconstruction for Osteoradionecrosis.

PURPOSE: Although negative-pressure wound therapy (NPWT) for complicated wounds has been extensively studied, it is rarely used in cases involving a submandibular fistula due to radiation-induced osteoradionecrosis of the mandible. This study aimed to investigate the efficacy of NPWT for submandibular fistulas after reconstruction for osteoradionecrosis. PATIENTS AND METHODS: Nine patients with submandibular fistulas after reconstruction for osteoradionecrosis treated with NPWT between 2011 and 2014 were included in the study. The wound healing was documented. RESULTS: The NPWT device was removed postoperatively between days 7 and 12 (mean duration, 9.6 days). The wound bed was filled with healthy granulation tissue, and successful healing by second intention was observed in all patients within 2 weeks. No complications were observed. The follow-up ranged from 4 to 27 months (mean, 18 months); the fistulas exhibited excellent healing, and no recurrence or infection was observed. CONCLUSIONS: NPWT is a safe, effective technique for managing submandibular fistulas after reconstruction for osteoradionecrosis.