Objective To explore the possibility of rapamycin to up-regulate radiosensitivity of nasopharyngeal carcinoma (NPC) and its molecular mechanism.Methods In vitro,with untreated cells as the control,NPC cells were treated with rapamycin,irradiation (IR),or both rapamycin and IR.Phosphorylation of S6 and GSK3β,expression of Cyclin D1,clonogenic survival,number of residual γH2AX foci,and cell cycle status between study groups were compared.In vivo,athymic mice bearing CNE1 tumor were similarly treated.Tumor weight,Cyclin D1 and phosphorylated S6 in the xenograft model were compared between study groups.Results The results showed that rapamycin alone decreased the phosphorylation of S6 and glycogen synthase kinase 3 β (GSK3β),and the expression of Cyclin D1 in NPC cells.Thus,rapamycin-treated NPC cells had lower cell viability,higher DNA damage and more G1 arrest than the control,which was reflected by the in vivo study that rapamycin significantly attenuated tumor growth and decreased the levels of Cyclin D1 and phosphorylated S6.Moreover,the combination of rapamycin and IR caused the highest cell death,DNA damage,G1 arrest and tumor regression compared to those treated either alone.Conclusions Rapamycin up-regulate NPC radiosensitivity by inhibiting signal transduction of Akt/mammalian target of rapamycin (mTOR)/S6 pathway and Akt/GSK3β pathway,and by downregulating Cyclin D1 expression.

Purpose The aim of this study is to investigate the relationship between the expression of kinesin family member C1(KIFC1)in endometrioid carcinoma and clinicopathological features and prognosis of endometrioid carcinoma patients.Methods The expression of KIFC1 in 30 cases of paracancer-ous endometrium and 95 cases of endometrioid carcinoma was detected by immunohistochemical SP method.qRT-PCR and Western blot were used to detect the expression level of mRNA and protein of KIFC1 in 30 pairs of fresh cancer tissues and ad-jacent non-cancer tissues.Furthermore,the relationship between KIFC1 protein expression and survival time was analyzed by TC-GA database,and their clinicopathologic features were analyzed.Results The immunohistochemistry results showed the positive rate of KIFC1 in endometrioid carcinoma(61.05％)was signifi-cantly higher than that in the neighboring noncancerous tissue(13.33％),and the difference was statistically significant(P＜0.05).The expression of KIFC1 was correlated with myometrial invasion,FIGO stage and lymphatic metastasis(all P＜0.05).The relative expression of KIFC1 mRNA in endometrioid carci-noma(2.99±0.59)was significantly higher than that in the neighboring noncancerous tissue(1.00±0.29),and there was significant difference(P＜0.05).The relative expression of KIFC1 protein in endometrioid carcinoma(1.70±0.36)was significantly higher than that in the neighboring noncancerous tissue(0.72±0.17),and there was significant difference(P＜0.05).Furthermore,elevated KIFC1 expression was positive-ly correlated with a poorer prognosis.Conclusion KIFC1 is upregulated in endometrioid carcinoma and associated with poor prognosis of patients,KIFC1 was expected to be a potential ther-apeutic target and prognostic indicator for endometrioid carcino-ma.

OBJECTIVE: To investigate the expression of microRNA miR-431-5p in gastric cancer (GC) tissues and its effects on apoptosis and mitochondrial function in GC cells. METHODS: The expression level of miR-431-5p in 50 clinical samples of GC tissues and paired adjacent tissues was detected using real-time fluorescence quantitative PCR, and its correlation with the clinicopathological features of the patients was analyzed. A cultured human GC cell line (MKN-45 cells) were transfected with a miR-431-5p mimic or a negative control sequence, and the cell proliferation, apoptosis, mitochondrial number, mitochondrial potential, mitochondrial permeability transition pore (mPTP), reactive oxygen species (ROS) production and adenosine triphosphate (ATP) content were detected using CCK-8 assay, flow cytometry, fluorescent probe label, or ATP detection kit. The changes in the expression levels of the apoptotic proteins in the cells were detected with Western blotting. RESULTS: The expression level of miR-431-5p was significantly lower in GC tissues than in the adjacent tissues (P < 0.001) and was significantly correlated with tumor differentiation (P=0.0227), T stage (P=0.0184), N stage (P=0.0005), TNM stage (P=0.0414) and vascular invasion (P=0.0107). In MKN-45 cells, overexpression of miR-431-5p obviously inhibited cell proliferation and induced cell apoptosis, causing also mitochondrial function impairment as shown by reduced mitochondrial number, lowered mitochondrial potential, increased mPTP opening, increased ROS production and reduced ATP content. Overexpression of miR-431-5p significantly downregulated the expression of Bcl-2 and increased the expressions of pro-apoptotic proteins p53, Bcl-2 and cleaved caspase-3 protein. CONCLUSION The expression of miR-431-5p is down-regulated in GC, which results in mitochondrial function impairment and promotes cell apoptosis by activating the Bax/Bcl-2/caspase3 signaling pathway, suggesting the potential role of miR-431-5p in targeted therapy for GC.
Humans ; Apoptosis/genetics* ; bcl-2-Associated X Protein ; Caspase 3 ; Cell Line, Tumor ; Cell Proliferation/genetics* ; MicroRNAs/metabolism* ; Mitochondria/metabolism* ; Mitochondrial Permeability Transition Pore ; Reactive Oxygen Species ; Stomach Neoplasms/pathology*