Gastroenterology cancer research group at HU Cancer Center

Dr. Hassan Ashktorab is Professor in the Departments of Medicine. He serves, or has served as the member of gastrointestinal working group in the Howard University Cancer Center, executive member of The Howard University Cancer Center, Adjunct Professor at The Department of Genetics and Human Genetics and the Director of Microarray facility at Howard University and former Chair of College of Medicine Research committee. He is a member of the Editorial boards of PLoS One, Digestive Diseases and Science, World Journal of Gastroenterology and Gouvaresh and former Editorial Board member of Gut. He has been awarded several NIH grants including RO3, RO1 and DOD grants. He received the HU-COM Outstanding Researcher Award in 2011. He has been a member of different NIH study sections since 2005. Dr. Ashktorab’s group focus is on epigenetics, genetics and epidemiology of gastrointestinal cancers especially colorectal cancer.

Gastroenterology Research:
Gastroenterology laboratory is investigating the molecular mechanisms governing cellular proliferation, including epigenetic and genetic influence during oncogenic transformation and tumorigenesis. The long term goals include the identification and characterization of epigenetic factors such as DNA methylation, miRNA and histone modifications that play a central and direct role in the initiation and/or progression of human cancers, specifically gastric and colon cancer. This includes research on chromatin modification through methylation or acetylation of genes/histones that may play critical roles in the regulation of transcription of many genes, leading to alteration of cell function and cell cycle. In addition, the detection of DNA methylation biomarkers for both early detection and prognosis is part of our interests using Next Generation Sequencing (NGS). We have recently detected several epigenetic biomarkers that are hypermethylated significantly in tumors from African Americans compared to Caucasians. Dr. Ashktorab’s translational/clinical research focuses on the African American population, investigating genomic instability and gene silencing in patients with adenoma and colorectal cancer. This is a critical step for the understanding of the onset of cancer progression in African Americans with the goal of tackling this health disparity in this population.

NGS is revolutionizing medicine and health care approaches. As it becomes cheaper and more accessible, more in-depth personalized genomic information will be available that dictates more appropriate and individualized approaches for both detection and treatment.
Dr. Ashktorab’s NGS research recently identified novel mutations in African Americans with colorectal cancer which were highlighted in the Journal Cancer. His group is working toward biomarkers identification in early to late colorectal carcinogenesis. One of the genes that is an early marker in colorectal carcinogenesis is APC. This gene is part of WNT pathway and his group found novel mutations in African Americans with colorectal cancer which is highlighted in Cancer and PNAS 2015.
The identification of these biomarkers will help in the detection, prognostic and treatment of the patients. The NGS research is followed by targeted exome sequencing for gene panels in detect colorectal cancer specifically in African Americans.
Much of the sporadic colorectal cancer’s underlying genetic mutations (driver genes) are unknown in patients from specific ethnic groups such as African Americans. We also reported the identification of distinct novel variants from adenoma and CRC patients in mismatch repair (MMR) genes MHS3 and MSH6, and in PIK3CA.

A new line of research was recently developed with Dr. Brim in the context of the role that the gut microbiota might play in the initiation and progression of colon neoplasia. Dr. Brim is a faculty at the Department of Pathology. Several publications have pointed to potential roles of specific bacteria in triggering genetic and epigenetic events such as those described in colon carcinogenesis. The primary goal of this line of research is to define specific bacteria that associate with higher risk of neoplasia. This will likely offer the opportunity to intervene at the gut microbiota’s level to reduce the risk of colon carcinogenesis.

We are also collaborating with Dr. Laiyemo, a gastroenterologist and Dr. Nouraie Faculty at the College of medicine, on several epidemiological studies that seek to assess factors at play in the adherence to colonoscopy and treatment in minority patients.

Along with our genetic, epigenetic, microbiomic and epidemiological studies that target colorectal cancer in African Americans, we are also investigating such a disease in other minorities such as Hispanics. We are also investigating other gastrointestinal diseases through several ongoing epidemiological studies such as hepatic fibrosis, hepatocellular carcinoma, gastroesophageal reflux disease, esophageal cancer and anal cancer in African Americans among several other projects.

Please visit PubMed for the recent publications.