UA Gastroenterology Chief Dr. Juanita Merchant Elected to National Academy of Medicine Governing Council

Dr. Juanita Merchant with the National Academy of Medicine logoJuanita L. Merchant, MD, PhD, a University of Arizona professor of medicine and chief of the Division of Gastroenterology and Hepatology, was informed earlier this week that she was chosen by her colleagues at the National Academy of Medicine (NAM) for a three-year term on the governing NAM Council.

In 2008, Dr. Merchant was elected to the National Academy of Medicine and previously was appointed a member of the National Institutes of Health (NIH) Council of Councils. Her term for the NIH council has since been completed. Separately, she became a member of the Board of Scientific Counselors for the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), one of 27 institutes at the NIH, in 2016 and will begin her term as board chair starting in June 2019.

“I'm really excited by my election to the NAM Council because I was voted on by fellow members of the National Academy of Medicine. It is an opportunity to have a broader impact on medicine and science, exclusive of my research on GI related disorders and as a gastroenterologist,” Dr. Merchant said.

Dr. Monica KraftUpon hearing the news, Monica Kraft, MD, chair of the UA Department of Medicine and the Robert and Irene Flinn Endowed Professor of Medicine at the UA College of Medicine – Tucson, said, “That is fantastic! Congratulations.” The gastroenterology division is one of 14 in the department, one of six original and the largest department at the college.

Dr. Merchant’s term on the NAM Council is effective July 1, 2019, through June 30, 2022. Her first meeting as a member is July 14-15, with the National Academies of Sciences, Engineering, and Medicine’s Health Leadership in the National Academies of Sciences building in Washington, DC.

Dr. Victor J. Dzau“I am so pleased to have your expertise and wisdom to help guide and oversee the work of the NAM during the next three years,” said Victor J. Dzau, MD, NAM president, a former cardiologist, chancellor for health affairs and president and CEO of the Duke University Health System and the James B. Duke Professor of Medicine at Duke University, in a letter to Dr. Merchant dated Dec. 14.

Dr. Merchant was recruited by the UA Department of Medicine this past year from the University of Michigan, presenting at last year’s DOM P.I. Poster Session in January (this year’s Third Annual P.I. Poster Session is Jan. 9) and joining the UA faculty in July.

Also a member of the Cancer Biology Research Program at the UA Cancer Center, she is a renowned physician-scientist whose research focus centers on gastric and colon cancer, in particular studying the role of bacterial colonization in the development of gastric cancer and molecular and genetic pathways that govern mechanisms of gastrinoma development.

This past fall, she was awarded two four-year, NIH/NIDDK R01 Research Project Grants valued at nearly $3 million combined.

The first, “MDSC Polarization and Helicobacter-Induced Gastric Metaplasia,” is funded from this past September through May 2022. It involves co-investigators GI physiologist Linda Samuelson, PhD, and gastroenterologist Kim Turgeon, MD, from the University of Michigan. The second, “Transcriptional Control of Gastrin,” is a continuation of a project she has received funding on since 1993. Her co-investigators on that one are pathologist Jolanta Grembecka, PhD, and endocrinologist Tobias Else, MD, also from the University of Michigan.

The “MDSC Polarization” grant, Dr. Merchant noted, focuses on implications of the SHH gene (known as sonic hedgehog) in gastric cancer, which occurs when cancer cells form in the epithelial layer, or lining, of the stomach. Stomach cancer affects more than 25,000 people a year in the United States, two-thirds of whom are age 65 or older and male, with about 11,000 people dying from it annually—according to the American Cancer Society.

“The myeloid differentiation factor Schlafen4 (Slfn4) marks a subset of Myeloid Derived Suppressor Cells (MDSCs) in the stomach that coincides with Helicobacter-induced intestinal metaplasia”—that’s generally considered a precancerous condition, Dr. Merchant said. “We fluorescently tag these immune cells and then analyze their function in the stomach and identify products they secrete. We have found Slfn4+-MDSCs secrete microRNAs that not only modulate T cell immune response but also stimulate epithelial proliferation. We are examining the levels of the microRNA to determine whether it might be used as a biomarker.”

The focus of the "Transcriptional Control of Gastrin" grant, Dr. Merchant added, is to understand the origins of MEN1 gastrinomas, or endocrine-related tumors that typically appear in the second portion of the duodenum in the small intestine. “We have found that these tumors might arise from a neural crest-derived cell (glial) instead of the epithelium. This could change our approach to treatment for these tumors,” she said.

Dr. Merchant grew up in Los Angeles and attended Stanford University for her undergraduate studies, later earning her medical degree and a doctorate at Yale University School of Medicine. Afterward, she did her internship and residency in internal medicine as well as a clinical and research fellowship at Boston’s Massachusetts General Hospital, before completing a gastroenterology fellowship at the University of California Los Angeles. Prior to coming to the UA, she had been on faculty at the University of Michigan since 1991. She is board certified in internal medicine and gastroenterology.

She has written or co-written well over 75 peer-reviewed research publications and is editor or co-editor of two books and several book chapters.

About the National Academy of Medicine
The National Academy of Medicine, formerly the Institute of Medicine, is a U.S. nonprofit, non-governmental organization that provides unbiased, objective and authoritative evaluation of health-related issues, health policy and medicine. The goal is to provide a balanced discussion of difficult research questions in all these areas. NAM is a part of the National Academies of Science, Engineering & Medicine logoNational Academies of Sciences, Engineering, and Medicine, along with the National Academy of Sciences, National Academy of Engineering and the National Research Council. Many of the studies funded through the Academies are requested by the federal government, but they are independent of the it, operating through a volunteer workforce of scientists and other experts under a formal peer-review system. Established in 1970, the NAM has more than 2,000 members. Learn more:

(Dr. Merchant’s research mentioned in this article was supported by National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Diseases grants for award numbers 1R01DK118563-01 and 2R01DK045729- 24A1.)

“Drs. Breathett, Merchant Spotlight DOM Research at 2nd Innovations & Inventions Fair” | (see photo album & video here) Posted Oct. 18, 2018
“Colon Cancer Expert Joins UA/Banner as Chief of Gastroenterology” | Posted July 18, 2018
“Featured Spotlight: National Expert on Colon Cancer Begins as Gastroenterology Chief at UA/Banner” | Posted July 6, 2018
“DOM P.I. Research Poster Night Continues to Shine in Second Year” | Posted Jan. 30, 2018

Release Date: 
12/18/2018 - 1:15pm