John R. Stroehlein

Hippo Coactivator YAP1 Upregulates SOX9 and Endows Esophageal Cancer Cells with Stem-like Properties

Cancer stem cells (CSC) are purported to initiate and maintain tumor growth. Deregulation of normal stem cell signaling may lead to the generation of CSCs; however, the molecular determinants of this process remain poorly understood. Here we show that the transcriptional coactivator YAP1 is a major determinant of CSC properties in nontransformed 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 CSC properties. Conversely, shRNA-mediated knockdown of YAP1 or SOX9 in transformed cells attenuates CSC phenotypes in vitro and tumorigenicity in vivo. The small-molecule inhibitor of YAP1, verteporfin, significantly blocks CSC properties in cells with high YAP1 and a high proportion of ALDH1(+). Our findings identify YAP1-driven SOX9 expression as a critical event in the acquisition of CSC properties, suggesting that YAP1 inhibition may offer an effective means of therapeutically targeting the CSC population.

Chemotherapy for primary adenocarcinoma of the small bowel

The results of chemotherapy for patients with advanced adenocarcinoma of the small bowel treated at U. T. M. D. Anderson Hospital between 1950 and 1980 were analyzed. A total of 21 single‐agent and multidrug chemotherapy regimens were given to 14 patients. 5‐Fluorouracil, Adriamycin, mitomycin C, and nitrosourea compounds were the most commonly used chemotherapeutic agents. Fluoropyrimidines, used alone or in combination with the other agents mentioned above, resulted in objective tumor regression in 3 patients (1 partial and 2 minor responses); while 9 additional patients had stable disease. The partial response (PR) was obtained with ftorafur in a patient with supraclavicular lymphadenopathy and hepatic metastasis. Median duration of survival for patients treated with chemotherapy was 9 months. Results of this study show that adenocarcinoma of the small bowel appears to be somewhat less responsive to chemotherapeutic agents than adenocarcinoma arising in the stomach, as reported in the literature. Systematic evaluations of the efficacy of new antitumor agents is indicated to improve results of treatment for advanced small bowel adenocarcinomas. Cancer 53:23‐25, 1984.

Metformin sensitizes chemotherapy by targeting cancer stem cells and the mTOR pathway in esophageal cancer

Our clinical study indicates esophageal adenocarcinoma patients on metformin had a better treatment response than those without metformin. However, the effects of metformin and the mechanisms of its action in esophageal cancer (EC) are unclear. EC cell lines were used to assess the effects of metformin alone or in combination with 5-fluorouracil on survival and apoptosis. RPPA proteomic array and immunoblots were used to identify signaling affected by metformin. Standard descriptive statistical methods were used. Reduction in cell survival and induction of apoptosis by metformin were observed in several EC cell lines. The use of metformin in combination with 5-FU significantly sensitized EC cells to the cytotoxic effect of 5-FU. RPPA array demonstrated that metformin decreased various oncogenes including PI3K/mTORsignaling and survival/cancer stem cell-related genes in cells treated with metformin compared with its control. Immunoblots and transcriptional analyses further confirm that metformin downregulated these CSC-related genes and the components of the mTOR pathway in a dose-dependent manner. Sorted ALDH-1+ cell tumor sphere forming capacity was preferentially reduced by metformin. Finally, metformin reduced tumor growth in vivo and when combined with FU, there was synergistic reduction in tumor growth. Metformin inhibits EC cell growth and sensitizes EC cells to 5-FU cytotoxic effects by targeting CSCs and the components of mTOR. The present study supports our previous clinical observations that the use of metformin is beneficial to EC patients. Metformin can complement other therapeutic combinations to effectively treat EC patients.

Thrombocytopenia and gastrointestinal hemorrhage in the cancer patient: prevalence of unmasked lesions

Some coagulation deficiencies are known to cause bleeding by unmasking existing gastrointestinal pathology, as opposed to directly causing mucosal blood loss. Characteristics and etiology of gastrointestinal hemorrhage associated with thrombocytopenia have not been analyzed. Our objectives were to correlate the distribution and cause of gastrointestinal bleeding, as diagnosed by fiberoptic endoscopy, with the severity of thrombocytopenia. One hundred thirty-three patients were divided into three groups, determined by platelet count at the time of bleeding (group A: less than 20,000/mm3; group B: 20,000 to 40,000/mm3; group C greater than 40,000/mm3). Results of 187 endoscopies revealed unifocal sources of blood loss in over 50% of each group, and diffuse mucosal oozing independent of gastrointestinal pathology was seen in only 1% of group C. The only significant difference (p = 0.04) comparing unifocal, multifocal, and diffuse sources of bleeding was observed between groups A and C, where in the distribution of multifocal or diffuse sources of bleeding was more common in group A. Esophagitis was more common and gastric ulceration less common in group A. No endoscopic complications occurred. Gastrointestinal bleeding associated with thrombocytopenia is most commonly due to co-existent gastrointestinal pathology as opposed to diffuse mucosal bleeding. Even when an inflammatory process, such as esophagitis or gastritis, affects a particular organ, bleeding is usually unifocal or multifocal as opposed to diffuse even in the presence of moderately severe thrombocytopenia.

Loss of TGF-β Adaptor β2SP Activates Notch Signaling and SOX9 Expression in Esophageal Adenocarcinoma

TGF-β and Notch signaling pathways play important roles in regulating self-renewal of stem cells and gastrointestinal carcinogenesis. Loss of TGF-β signaling components activates Notch signaling in esophageal adenocarcinoma, but the basis for this effect has been unclear. Here we report that loss of TGF-β adapter β2SP (SPNB2) activates Notch signaling and its target SOX9 in primary fibroblasts or esophageal adenocarcinoma cells. Expression of the stem cell marker SOX9 was markedly higher in esophageal adenocarcinoma tumor tissues than normal tissues, and its higher nuclear staining in tumors correlated with poorer survival and lymph node invasion in esophageal adenocarcinoma patients. Downregulation of β2SP by lentivirus short hairpin RNA increased SOX9 transcription and expression, enhancing nuclear localization for both active Notch1 (intracellular Notch1, ICN1) and SOX9. In contrast, reintroduction into esophageal adenocarcinoma cells of β2SP and a dominant-negative mutant of the Notch coactivator mastermind-like (dnMAN) decreased SOX9 promoter activity. Tumor sphere formation and invasive capacity in vitro and tumor growth in vivo were increased in β2SP-silenced esophageal adenocarcinoma cells. Conversely, SOX9 silencing rescued the phenotype of esophageal adenocarcinoma cells with loss of β2SP. Interaction between Smad3 and ICN1 via Smad3 MH1 domain was also observed, with loss of β2SP increasing the binding between these proteins, inducing expression of Notch targets SOX9 and C-MYC, and decreasing expression of TGF-β targets p21(CDKN1A), p27 (CDKN1B), and E-cadherin. Taken together, our findings suggest that loss of β2SP switches TGF-β signaling from tumor suppression to tumor promotion by engaging Notch signaling and activating SOX9.

Palliation of malignant ascites by the LeVeen peritoneo‐venous shunt

A LeVeen peritoneo‐venous shunt was placed in each of 5 patients under local anesthesia to relieve symptomatic malignant ascites. All patients had marked ascites due to histologically documented intraabdominal carcinomatosis, extensive hepatic neoplasm, or a combination of malignant ascites and severe parenchymal liver disease. Cases included metastatic breast carcinoma, pancreatic carcinoma, melanoma, and primary cholangiocarcinoma. Prompt relief of respiratory distress and discomfort associated with tense ascites was achieved in all patients; however, survival was short (one‐week to seven months) due to advanced disease. The LeVeen shunt can provide effective palliation of malignant ascites in carefully selected symptomatic patients.

Natural Language Processing As an Alternative to Manual Reporting of Colonoscopy Quality Metrics

BACKGROUND AND AIMS The adenoma detection rate (ADR) is a quality metric tied to interval colon cancer occurrence. However, manual extraction of data to calculate and track the ADR in clinical practice is labor-intensive. To overcome this difficulty, we developed a natural language processing (NLP) method to identify adenomas and sessile serrated adenomas (SSAs) in patients undergoing their first screening colonoscopy. We compared the NLP-generated results with that of manual data extraction to test the accuracy of NLP and report on colonoscopy quality metrics using NLP. METHODS Identification of screening colonoscopies using NLP was compared with that using the manual method for 12,748 patients who underwent colonoscopies from July 2010 to February 2013. Also, identification of adenomas and SSAs using NLP was compared with that using the manual method with 2259 matched patient records. Colonoscopy ADRs using these methods were generated for each physician. RESULTS NLP correctly identified 91.3% of the screening examinations, whereas the manual method identified 87.8% of them. Both the manual method and NLP correctly identified examinations of patients with adenomas and SSAs in the matched records almost perfectly. Both NLP and the manual method produced comparable values for ADRs for each endoscopist and for the group as a whole. CONCLUSIONS NLP can correctly identify screening colonoscopies, accurately identify adenomas and SSAs in a pathology database, and provide real-time quality metrics for colonoscopy.

Adenoma detection in patients undergoing a comprehensive colonoscopy screening

Measures shown to improve the adenoma detection during colonoscopy (excellent bowel preparation, cecal intubation, cap fitted colonoscope to examine behind folds, patient position change to optimize colon distention, trained endoscopy team focusing on detection of subtle flat lesions, and incorporation of optimum endoscopic examination with adequate withdrawal time) are applicable to clinical practice and, if incorporated are projected to facilitate comprehensive colonoscopy screening program for colon cancer prevention. To determine adenoma and serrated polyp detection rate under conditions designed to optimize quality parameters for comprehensive screening colonoscopy. Retrospective analysis of data obtained from a comprehensive colon cancer screening program designed to optimize quality parameters. Academic medical center. Three hundred and forty‐three patients between the ages of 50 years and 75 years who underwent first screening colonoscopy between 2009 and 2011 among 535 consecutive patients undergoing colonoscopy. Comprehensive colonoscopy screening program was utilized to screen all patients. Cecal intubation was successful in 98.8% of patients. The Boston Bowel Preparation Scale for quality of colonoscopy was 8.97 (95% confidence interval [CI]; 8.94, 9.00). The rate of adenoma detection was 60% and serrated lesion (defined as serrated adenomas or hyperplastic polyps proximal to the splenic flexure) detection was 23%. The rate of precancerous lesion detection (adenomas and serrated lesions) was 66%. The mean number of adenomas per screening procedure was 1.4 (1.2, 1.6) and the mean number of precancerous lesions (adenomas or serrated lesions) per screening procedure was 1.6 (1.4, 1.8). Retrospective study and single endoscopist experience. A comprehensive colonoscopy screening program results in high‐quality screening with high detection of adenomas, advanced adenomas, serrated adenomas, and multiple adenomas.

Genetic and intermediate phenotypic susceptibility markers of gastric cancer in Hispanic Americans: a case-control study.

Hispanics are the largest nonwhite ethnic group in the US population, and they have higher incidence and mortality rates for gastric cancer (GC) than whites and Asians. Studies have identified several genetic susceptibility loci and intermediate phenotypic biomarkers for GC in whites and Asians. No studies have evaluated genetic susceptibility and intermediate phenotypic biomarkers in Hispanics.

Gastrointestinal hemorrhage in the cancer patient

The usefulness of fiberoptic endoscopy, performed to identify the cause(s) of gastrointestinal bleeding in cancer patients was assessed by (1) identifying the clinical presentation of bleeding, (2) evaluating the safety and diagnostic yield of fiberoptic endoscopy, (3) determining the frequency distribution of causes of bleeding, and (4) evaluating the clinical course following acute gastrointestinal bleeding in a cancer patient population. Hematemesis, melena, and hematochezia were observed in decreasing order of frequency as manifestations of bleeding. Of 187 endoscopic procedures performed on 133 patients, 75% were bleeding from benign lesions with the majority due to gastric ulceration, gastritis, or duodenal ulceration. One third of patients with tumors involving the gastrointestinal tract were bleeding from another source. Mortality from major hemorrhage was 8%; 55% of patients were alive at the end of 2 years. Endoscopy was performed without complications and contributed to medical management, angiographic therapy, and surgical planning.