On why those two molecular monomers could increase the sensitivity to these agents. Topoisomerase1 (TOPO1) regulates DNA supercoiling during replication by causing single-strand breaks 10781694 and relegation. It has been reported that EVO could inhibit type TOPO1 and II exhibiting enhanced Apocynin site inhibition against camptothecin (CPT) resistant human leukaemia cells [8]. However, in the current study, there was no significant enhanced inhibition on freshlyremoved gastric tumor tissues when combined EVO and CPT-11 compared with CPT-11 alone. There was no significant correlation between TOPO1 mRNA expression levels and CPT-11 or EVO sensitivity, either. The differences in cancer types and the heterogeneity of freshly-removed tumor tissues may account for the SMER 28 site differentiation between our results and previous study. For further validation, gastric cell line study needs to be carried out and more freshly-removed samples need to be included and analyzed.Aprataxin (APTX) is a protein in the histidine triad domain super family involved in the repair of single-stranded DNA strand breaks. It has been reported that colon cancer patients with lower levels of APTX might be more sensitive to CPT-11 based chemotherapy [28]. In the current study, a weak but significant correlation was observed between APTX mRNA expression levels and CPT-11 sensitivity or EVO sensitivity, which means APTX may be a possible predictive biomarker for EVO sensitivity. Therefore, we hypotheses that patient with low mRNA expression level of APTX may be more sensitive to EVO. This finding is novel and has not been reported ever before. Nevertheless, the hypothesis needs to be explored by deeper studies such as the mRNA and protein expression of APTX in the EVO-sensitive and EVO-resistant cells. We will also use siRNA to confirm the relationship between EVO sensitivity and APTX mRNA expression level. The chemosensitivity assay we adopted here included HDRA for in vitro testing. HDRA has been demonstrated by varieties of studies as a useful predictor for chemosensitivity at different cancerous sites, including gastrointestinal cancer [29]. The collagen sponge-gel-supported histoculture conserves the original phenotypic characteristics and potential cellular interactions of tumor cells [16], and highly mimics the growth of the tumors in vivo [30]. It has been reported in gastric cancer [29], esophageal cancer [16], breast cancer [31], oral squamous cell carcinomas [32] and head and neck cancer [33] that efficacy rate for an individual agent using HDRA assay in vitro has a considerable good correlation with clinical response rate to each agent. We designed 8 parallel culture wells for sensitivity testing and 8 parallel culture wells for control from different parts of one patient’s tumor sample avoiding tumor heterogeneity. We have recognized that any kind of in vitro may have defects, thus, more adequately designed clinical trials will be carried out for further confirmation.Synergistic Anticancer Effects of PPI and EVOIn conclusion, this study provided evidence for PPI and EVO to be useful assistants for Pt and 5-FU based chemotherapy. Patients with gastric cancer receiving this regimen may get benefit from the administration of PPI and EVO included TCM therapy.Table S1 The effects of PPI and EVO on reverse Pt resistance at different doses. (DOC)Author Contributions Supporting InformationFigure S1 The RT-PCR amplification curves of differentConceived and designed the experiments: BL JS. Performe.On why those two molecular monomers could increase the sensitivity to these agents. Topoisomerase1 (TOPO1) regulates DNA supercoiling during replication by causing single-strand breaks 10781694 and relegation. It has been reported that EVO could inhibit type TOPO1 and II exhibiting enhanced inhibition against camptothecin (CPT) resistant human leukaemia cells [8]. However, in the current study, there was no significant enhanced inhibition on freshlyremoved gastric tumor tissues when combined EVO and CPT-11 compared with CPT-11 alone. There was no significant correlation between TOPO1 mRNA expression levels and CPT-11 or EVO sensitivity, either. The differences in cancer types and the heterogeneity of freshly-removed tumor tissues may account for the differentiation between our results and previous study. For further validation, gastric cell line study needs to be carried out and more freshly-removed samples need to be included and analyzed.Aprataxin (APTX) is a protein in the histidine triad domain super family involved in the repair of single-stranded DNA strand breaks. It has been reported that colon cancer patients with lower levels of APTX might be more sensitive to CPT-11 based chemotherapy [28]. In the current study, a weak but significant correlation was observed between APTX mRNA expression levels and CPT-11 sensitivity or EVO sensitivity, which means APTX may be a possible predictive biomarker for EVO sensitivity. Therefore, we hypotheses that patient with low mRNA expression level of APTX may be more sensitive to EVO. This finding is novel and has not been reported ever before. Nevertheless, the hypothesis needs to be explored by deeper studies such as the mRNA and protein expression of APTX in the EVO-sensitive and EVO-resistant cells. We will also use siRNA to confirm the relationship between EVO sensitivity and APTX mRNA expression level. The chemosensitivity assay we adopted here included HDRA for in vitro testing. HDRA has been demonstrated by varieties of studies as a useful predictor for chemosensitivity at different cancerous sites, including gastrointestinal cancer [29]. The collagen sponge-gel-supported histoculture conserves the original phenotypic characteristics and potential cellular interactions of tumor cells [16], and highly mimics the growth of the tumors in vivo [30]. It has been reported in gastric cancer [29], esophageal cancer [16], breast cancer [31], oral squamous cell carcinomas [32] and head and neck cancer [33] that efficacy rate for an individual agent using HDRA assay in vitro has a considerable good correlation with clinical response rate to each agent. We designed 8 parallel culture wells for sensitivity testing and 8 parallel culture wells for control from different parts of one patient’s tumor sample avoiding tumor heterogeneity. We have recognized that any kind of in vitro may have defects, thus, more adequately designed clinical trials will be carried out for further confirmation.Synergistic Anticancer Effects of PPI and EVOIn conclusion, this study provided evidence for PPI and EVO to be useful assistants for Pt and 5-FU based chemotherapy. Patients with gastric cancer receiving this regimen may get benefit from the administration of PPI and EVO included TCM therapy.Table S1 The effects of PPI and EVO on reverse Pt resistance at different doses. (DOC)Author Contributions Supporting InformationFigure S1 The RT-PCR amplification curves of differentConceived and designed the experiments: BL JS. Performe.