Cancer stem cells are proposed to initiate and maintain tumor growth. Deregulation of normal stem cell signaling may lead to the generation of cancer stem cells (CSCs); however, the molecular determinants of this process remain poorly understood. Here we show that the transcriptional co-activator YAP1 is a major determinant of CSC properties in non-transformed cells and in esophageal cancer cells by direct upregulation of SOX9. YAP1 regulates the transcription of SOX9 through a conserved TEAD binding site in the SOX9 promoter. Expression of exogenous YAP1 in vitro or inhibition of its upstream negative regulators in vivo results in elevated SOX9 expression accompanied by the acquisition of CSCs properties. Conversely, shRNA-mediated knockdown of YAP1 or SOX9 in transformed cells attenuates CSC phenotypes in vitro and tumorigenecity in vivo. The small molecule inhibitor of YAP1, Verteporfin (VP) significantly blocks CSCs properties in cells with high YAP1 and a high proportion of ALDH1+. Our findings identify YAP1 driven SOX9 expression is a critical event in acquisition of CSC properties, suggesting that YAP1 inhibition may offer an effective means of therapeutically targeting the CSC population.

CRC patients showed significant differences in the intestinal environment, including alterations of microbiota, decreased SCFAs, and elevated pH. These changes are not a result of CRC progression but are involved in CRC onset.

Significant changes in the intestinal environment, including marked decreases in obligate anaerobes, increases in pathogenic bacteria, and reductions in SCFAs, were detected after surgery for CRC.

Esophageal fistula is a critical adverse event in patients treated with chemoradiotherapy (CRT) for locally advanced esophageal cancer. However, risk factors associated with esophageal fistula formation in patients receiving CRT have not yet been elucidated.We retrospectively analyzed data obtained from 140 patients who were enrolled in a phase II/III trial comparing low-dose cisplatin with standard-dose cisplatin administered in combination with 5-flurouracil and concomitant radiotherapy. Inclusion criteria were performance status (PS) 0 to 2 and histologically proven thoracic esophageal cancer clinically diagnosed as T4 and/or unresectable lymph node metastasis for which definitive CRT was applicable. Risk factors for esophageal fistula were examined with univariate analysis using Fisher exact test and multivariate analysis using logistic regression models.Esophageal fistula was observed in 31 patients (22%). Of these, 6 patients developed fistula during CRT. Median time interval between the date of CRT initiation and that of fistula diagnosis was 100 days (inter quartile range, 45–171). Esophageal stenosis was the only significant risk factor for esophageal fistula formation both in univariate (P = 0.026) and in multivariate analyses (odds ratio, 2.59; 95% confidence interval, 1.13–5.92, P = 0.025). Other clinicopathological factors, namely treatment arm, age, sex, PS, primary tumor location, T stage, lymph node invasion to adjacent organs, blood cell count, albumin level, and body mass index, were not risk factors fistula formation.Esophageal stenosis was a significant risk factor for esophageal fistula formation in patients treated with CRT for unresectable locally advanced thoracic esophageal squamous cell carcinoma.

Purpose: Operable thoracic esophageal/gastroesophageal junction carcinoma (EC) is often treated with chemoradiation and surgery but tumor responses are unpredictable and heterogeneous. We hypothesized that aldehyde dehydrogenase-1 (ALDH-1) could be associated with response. Methods: The labeling indices (LIs) of ALDH-1 by immunohistochemistry in untreated tumor specimens were established in EC patients who had chemoradiation and surgery. Univariate logistic regression and 3-fold cross validation were carried out for the training (67% of patients) and validation (33%) sets. Non-clinical experiments in EC cells were performed to generate complimentary data. Results: Of 167 EC patients analyzed, 40 (24%) had a pathologic complete response (pathCR) and 27 (16%) had an extremely resistant (exCRTR) cancer. The median ALDH-1 LI was 0.2 (range, 0.01 to 0.85). There was a significant association between pathCR and low ALDH-1 LI (p=<0.001; odds-ratio [OR]=0.432). The 3-fold cross validation led to a concordance index (C-index) of 0.798 for the fitted model. There was a significant association between exCRTR and high ALDH-1 LI (p=<0.001; OR=3.782). The 3-fold cross validation led to the C-index of 0.960 for the fitted model. In several cell lines, higher ALDH-1 LIs correlated with resistant/aggressive phenotype. Cells with induced chemotherapy resistance upregulated ALDH-1 and resistance conferring genes (SOX9 and YAP1). Sorted ALDH-1+ cells were more resistant and had an aggressive phenotype in tumor spheres than ALDH-1− cells. Conclusions: Our clinical and non-clinical data demonstrate that ALDH-1 LIs are predictive of response to therapy and further research could lead to individualized therapeutic strategies and novel therapeutic targets for EC patients.