Adaptive evolution of antioxidase-related genes in hypoxia-tolerant mammals.

To cope with the damage from oxidative stress caused by hypoxia, mammals have evolved a series of physiological and biochemical traits, including antioxidant ability. Although numerous research studies about the mechanisms of hypoxia evolution have been reported, the molecular mechanisms of antioxidase-related genes in mammals living in different environments are yet to be completely understood. In this study, we constructed a dataset comprising 7 antioxidase-related genes (CAT, SOD1, SOD2, SOD3, GPX1, GPX2, and GPX3) from 43 mammalian species to implement evolutionary analysis. The results showed that six genes (CAT, SOD1, SOD2, SOD3, GPX1, and GPX3) have undergone divergent evolution based on the free-ratio (M1) model. Furthermore, multi-ratio model analyses uncovered the divergent evolution between hypoxic and non-hypoxic lineages, as well as various hypoxic lineages. In addition, the branch-site model identified 9 positively selected branches in 6 genes (CAT, SOD1, SOD2, SOD3, GPX2, and GPX3) that contained 35 positively selected sites, among which 31 positively selected sites were identified in hypoxia-tolerant branches, accounting for 89% of the total number of positively selected sites. Interestingly, 65 parallel/convergent sites were identified in the 7 genes. In summary, antioxidase-related genes are subjected to different selective pressures among hypoxia-tolerant species living in different habitats. This study provides a valuable insight into the molecular evolution of antioxidase-related genes in hypoxia evolution in mammals.

The transcription factor KLF4 as an independent predictive marker for pathologic complete remission in breast cancer neoadjuvant chemotherapy: a case-control study.

BACKGROUND: To identify whether a stem cell biomarker, KLF4, may predict the pathologic tumor response to neoadjuvant chemotherapy for patients with locally advanced breast cancer. METHODS: Twelve locally advanced breast cancer patients who achieved pathologic complete remission (pCR) after neoadjuvant chemotherapy were identified and for each, three non-pCR breast cancer patients - matched for age, clinical tumor-node-metastasis stage, and neoadjuvant chemotherapy cycles - were selected. The relationship between KLF4 expression in the core needle biopsied cancer tissue and patient pCR rate was assessed using univariate and multivariate analysis. RESULTS: Receiver operating characteristic curve analysis showed that the patients with a histoscore of KLF4 expression >0.18 had a lower pCR rate. Multivariable analysis showed that higher KLF4 expression (odds ratio 0.013; 95% confidence interval 0.013-0.444; P=0.004) was independently correlated with a lower pCR rate after neoadjuvant chemotherapy. CONCLUSION: KLF4 overexpression was associated with lower pCR in locally advanced breast cancer patients undergoing neoadjuvant chemotherapy. This study suggests that KLF4 may serve as a predictor for pCR in patients with breast cancer after neoadjuvant chemotherapy.

Effect of intensity modulated radiotherapy combined with s-1-based chemotherapy in locally advanced gastric cancer patients.

BACKGROUND: The optimal radiotherapy technique and combination with systemic therapy in locally advanced gastric cancer patients are far from being resolved despite the fact that radiochemotherapy is becoming more attractive in contemporary clinical practice. PATIENTS AND METHODS: 40 patients with locally advanced gastric cancer received intensity-modulated radiotherapy (IMRT) at a dosage of 45-50.4 Gy concurrent with chemotherapy using S-1 solely or with a combination of oxaliplatin. Surgery was recommended for those who were evaluated as resectable. Sequential chemotherapy with various regimens was adopted based on the efficacy and tolerance of radiochemotherapy. RESULTS: The overall response rate was 75% according to Response Evaluation Criteria in Solid Tumors and Japanese Gastric Cancer Association criteria. 24 finally underwent surgery, with 22 (91.7%) receiving an R0 resection (resection for cure or complete remission). The overall pathological response rate was 37.5% (9/24). Patients receiving an R0 resection had a higher 2-year overall survival rate (64.7 vs. 16.2%, p = 0.001) and local relapse-free survival rate (90.2 vs. 29.3%, p = 0.000), while there was no difference in distant metastasis-free survival rate (66.1 and 48.1% p = 0.231). Hematological and gastrointestinal toxicities of grade 1 or grade 2 were relatively common. CONCLUSION: The high rate of R0 resections and low rate of locoregional recurrence suggest that IMRT combined with S-1-based chemotherapy is an effective treatment for locally advanced gastric cancer patients.

[Prognostic effect of postoperative resection-margin status for intraoperative positive resection margins in patients with advanced gastric cancer].

OBJECTIVES: To investigate prognostic effect of postoperative resection-margin status for intraoperatively positive resection margin in advanced gastric cancer and discuss the treatment choice for intraoperatively positive resection margins. METHODS: A retrospective study was investigated in 64 advanced gastric cancer patients with positive resection margin after potentially curative resection. The survival between 50 patients who was re-excised to a negative resection margin (NR group) and 14 patients who were left with positive resection margin (PR group) was compared. Prognostic factors were analyzed using univariate and multivariate Cox regression model analysis. RESULTS: The median survival in the PR group was 17.0 months (95%CI: 11.6 - 22.4) as compared with 23.0 months (95%CI: 20.5 - 25.5) in the NR group (P = 0.045). However, resection-margin status lost significance on multivariate analysis. In the subgroup of D2 lymphadenectomy, the median survival in the PR group and NR group were 17.0 months (95%CI: 12.0 - 22.0) and 24.0 months (95%CI: 19.8 - 28.1) respectively; multivariate analysis further identified resection margin status as an independent prognostic factor. CONCLUSIONS: Re-excision for intraoperatively positive margin to negative margin improves the prognosis of the patients with advanced gastric cancer, and re-excision is the first choice when intraoperative frozen section detects a positive margin. Routine frozen section of resection margin should be mandatory in all advanced gastric cancer undergoing potentially curative surgery.

Clinicopathologic variables predicting tumor response to neoadjuvant chemotherapy in patients with locally advanced gastric cancer.

BACKGROUND AND OBJECTIVES: To identify clinicopathologic variables that could predict pathologic tumor response to neoadjuvant chemotherapy for patients with locally advanced gastric cancer. METHODS: The study enrolled 108 patients who underwent neoadjuvant chemotherapy followed by surgery between July 2004 and December 2010. Tumor responses to neoadjuvant chemotherapy were assessed in terms of tumor regression. Statistical analyses were performed to identify factors associated with pathologic tumor response. RESULTS: Tumor regression was found in 22.2% (24/108) patients, patients with tumor regression observed better overall survival as compared to that of patients without tumor regression. Univariate and multivariate analyses observed that both tumor differentiation and tumor size were independent predictors of tumor regression. CONCLUSIONS: This study suggests that both tumor differentiation and tumor size is the most important clinical predicator of pathologic tumor response, it may be of benefit in the selection of treatment options in locally advanced gastric cancer.