H. pylori May Increase Risk of Stomach Cancer By Turning On Subset of Stem Cells

MedicalResearch.com Interview with:
Michael Sigal PhD

Clinical scientist of the Charité — Universitätsmedizin Berlin
Investigator at the Max Planck Institute for Infection Biology 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: We have previously found that H. pylori can colonize gastric glands and that in colonized glands the epithelial turnover was increased. We wanted to characterize the mechanisms that control the gland turnover in the stomach.

We found that Axin2, a classic Wnt target gene, marks two different subpopulations of cells with stem cell properties, one of which is Lgr5-positive and the other one Lgr5-negative. Both populations are affected by Rspondin 3, that is produced in myofibroblasts right beneath the stem cell compartment. Rspondin is crucial for stem cell signaling and knockout of Rspondin 3 in myofibroblasts results in loss of Lgr5 and Axin2 expression. Once we increased the bioavailability of Rspondin, that now could also interact with cells outside of the stem cell compartment, we noticed that the number of Axin2 positive stem cells dramatically increased. Of interest, only Lgr5-negative cells expanded in number and proliferate more, while the Lgr5-positive cells remained silenced.

Infection with Helicobacter pylori leads to an expansion of Axin2-positive cells which is driven by increased expression of Rspondin3. Expansion of the long lived stem cell pool could be an explanation for how H. pylori infection increases the risk for gastric cancer.

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Nanotechnology May Lead To Breath Test For Gastric Cancer

MedicalResearch.com Interview with:
Professor Hossam Haick Ph.D
Department of Chemical Engineering and Russell Berrie Nanotechnology Institute
Haifa, Israel

Medical Research: What is the background for this study? What are the main findings?

Dr. Haick: Our study is based on the hypothesis that timely detection of premalignant lesions (PMLs) may provide a tool to decrease either cancer mortality or incidence, thought, currently, there is no perfect non-invasive tool to screen for gastric cancer (GC) and the related premalignant lesions. Using 1002 samples collected from 501 volunteers, we show for the first time that premalignant lesions (PMLs) relevant to (gastric) cancer result in detectable differences in Volatile Organic Compound (VOC) signatures that can be detected and classified non-invasively through exhaled breath. We show additionally that these premalignant lesions can be well-discriminated from various stages of gastric cancer as well as other background stomach diseases.

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Gastric Cancer: Second Line Chemotherapy

MedicalResearch.com Interview with:
Dr. Shuichi Hironaka, MD
Clinical Trial Promotion Department, Chiba Cancer Center
666-2 Nitona-cho Chuo-ku Chiba-shi
Chiba, 260-8717 Japan

MedicalResearch.com: What are the main findings of the study?

Dr. Hironaka: This is the first randomized phase III trial comparing paclitaxel and irinotecan in second-line chemotherapy for advanced gastric cancer. This study showed that no statistically significant difference was observed between paclitaxel and irinotecan for overall survival. However, both are reasonable second-line treatment options for advanced gastric cancer.
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