an-immunofluorescent-method-for-characterization-barretts-esophagus

An Immunofluorescent Method for Characterization of Barrett&#8217;s Esophagus Cells

Esophageal adenocarcinoma (EAC) has an overall survival rate of less than 17% and incidence of EAC has risen dramatically over the past two decades. One ...

ST. JOSEPH'S HOSPITAL AND MEDICAL CENTER

Only local ablation (radiofrequency ablation, cryotherapy) or esophagectomy currently is available to treat high-grade dysplasia in Barrett's esophagus. Alternative treatments, specifically chemopreventive strategies, are lacking. Our understanding of the molecular changes of high-grade dysplasia in Barrett's esophagus offers an opportunity to inhibit neoplastic progression of high-grade dysplasia in Barrett's esophagus. Increased activity of the Src kinase and deregulation of the tumor suppressor p27 are features of malignant cells and high-grade dysplasia in Barrett's esophagus. Src phosphorylates p27, inhibiting its regulatory function and increasing cell growth and proliferation. We hypothesized that a small molecule inhibitor of Src might reduce the growth and reverse Src-mediated deregulation of p27 in Barrett's esophagus cells.

Dasatinib, a small molecule inhibitor of the Src kinase, reduces the growth and activates apoptosis in pre-neoplastic Barrett's esophagus cell lines: evidence for a noninvasive treatment of high-grade dysplasia.

Five-year survival rates for non-small cell lung cancer (NSCLC) have seen minimal improvement despite aggressive therapy with standard chemotherapeutic agents, indicating a need for new treatment approaches. Studies show inactivating mutations in the LKB1 tumor suppressor are common in NSCLC. Genetic and mechanistic analysis has defined LKB1-deficient NSCLC tumors as a phenotypically distinct subpopulation of NSCLC with potential avenues for therapeutic gain. In expanding on previous work indicating hypersensitivity of LKB1-deficient NSCLC cells to 2-deoxy-D-glucose (2DG), we find that 2DG has in vivo efficacy in LKB1-deficient NSCLC using transgenic murine models of NSCLC. Deciphering of the molecular mechanisms behind this phenotype reveals that loss of LKB1 in NSCLC cells imparts increased sensitivity to pharmacological compounds that aggravate ER stress. In comparison to NSCLC cells with functional LKB1, treatment of NSCLC cells lacking LKB1 with the ER stress activators (ERSA), tunicamycin, brefeldin A or 2DG, resulted in aggravation of ER stress, increased cytotoxicity, and evidence of ER stress-mediated cell death. Based upon these findings, we suggest that ERSAs represent a potential treatment avenue for NSCLC patients whose tumors are deficient in LKB1.

Aaron J. Fowler

Center for Thoracic Disease and Transplantation,
Heart and Lung Institute,
Center for Thoracic Disease and Transplantation, Heart and Lung Institute

ST. JOSEPH'S HOSPITAL AND MEDICAL CENTER

An Immunofluorescent Method for Characterization of Barrett’s Esophagus Cells

Aaron J. Fowler

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ST. JOSEPH'S HOSPITAL AND MEDICAL CENTER

An Immunofluorescent Method for Characterization of Barrett’s Esophagus Cells

Center for Thoracic Disease and Transplantation,
Heart and Lung Institute,
Center for Thoracic Disease and Transplantation, Heart and Lung Institute