Choice of Capecitabine or S1 in Combination with Oxaliplatin based on Thymidine Phosphorylase and Dihydropyrimidine Dehydrogenase Expression Status in Patients with Advanced Gastric Cancer

PURPOSE: To study the efficacy of capecitabine or S-1 plus oxaliplatin (CAPOX or SOX) for treating thymidine phosphorylase (TP)- or dihydropyrimidine dehydrogenase (DPD)-positive advanced gastric cancer.MATERIALS AND METHODS: Eighty-six patients with stage IIIC to IV gastric cancer were assessed for TP and DPD expression by immunohistochemistry. The association between CAPOX or SOX efficacy and TP/DPD expression was retrospectively analyzed.RESULTS: There were no significant differences in the objective remission rate (ORR, 52.27% vs. 47.62%; P>0.05), disease control rate (72.73% vs. 73.81%, P>0.05), progression-free survival (hazard ratio [HR], 1.119; 95% confidence interval [CI], 0.739–1.741; P=0.586), and overall survival (OS; HR, 0.855; 95% CI, 0.481–1.511; P=0.588) between CAPOX and SOX. A higher number of stage IV patients showed TP positivity, while DPD-positive patients predominantly showed intestinal type of gastric cancer. In TP-positive patients, the ORRs associated with CAPOX and SOX treatments were 57.14% and 38.10%, respectively; OS was better with CAPOX than with SOX (HR, 0.447; 95% CI, 0.179–0.978; P=0.046). Among DPD-positive patients, the SOX treatment-associated ORR (60.87%) was significantly higher than the CAPOX treatment-associated ORR (43.48%). Furthermore, SOX treatment resulted in better OS than did CAPOX treatment (HR, 2.020; 95% CI, 1.019–4.837; P=0.049).CONCLUSIONS: No significant difference in clinical efficacy was found between CAPOX and SOX. TP-positive patients might respond better to CAPOX while DPD-positive patients may respond better to SOX. Our findings might serve as a guide for personalized chemotherapy for gastric cancer.

The role of autophagy and mitogen-activated protein kinase in cisplatin chemoresistance of osteosarcoma cells / 中国医师进修杂志

Objective@#To analyze the roles of autophagy and mitogen-activated protein kinase(MAPK) in cisplatin chemotherapy resistance of osteosarcoma cells.@*Methods@#The appropriate concentration of cisplatin was determined by clonogenic assay and the cisplatin-resistant osteosarcoma cells were gained. Western Blot was used to detect changes in the expression of autophagy and MAPK signaling. RT-PCR was used to detect changes in autophagy related gene transcription levels, and AnnexinV-FITC and Z-VAD-FMK was used to detect apoptosis. The contribution of drug inhibition of autophagy and MAPK signaling pathway in drug resistance of osteosarcoma cells was explored.@*Results@#Cell cloning assay showed that 7.5 μmol/L cisplatin concentration induced significant apoptosis. Drug-resistant cell lines were obtained through continuous drug screening of 10 d. Morphological changes of osteosarcoma cells after drug resistance were observed under microscope. At the same time, the key factor of DNA repair PARP protein expression was upregulated significantly. RT-PCR and Western Blot results showed that cisplatin activated autophagy in osteosarcoma cells. The levels of ATG5 and LC3B-Ⅱ protein and mRNA were upregulated and significantly different (P<0.05). Meanwhile, AnnexinV-FITC and Z-VAD-FMK results showed that apoptosis was significantly increased after inhibition of autophagy (P<0.05). Osteosarcoma cells restored the sensitivity to cisplatin.And this process had the participation of MAPK signal.@*Conclusions@#Autophagy and MAPK signal play an important role at cisplatin resistance in osteosarcoma cells, and the results can provide strategies for improving the treatment with the osteosarcoma patients.