Biologic basis of disparities
At UC Davis Comprehensive Cancer Center, researchers are working to understand the biological mechanisms that may be at work in certain cancers that disproportionately affect different populations. They also are hunting for clues as to why certain types of cancer are more aggressive in one group or another, and why some populations respond differently when given the same treatment for the same disease.
Some examples of this work at UC Davis include:
Poorly understood type of liver disease more progressive in Hispanics and Pacific Islanders
Natalie Torok, an associate clinical professor of gastroenterology and hepatology, is a physician-scientist who studies a poorly understood type of liver disease called non-alcoholic steatohepatitis (NASH), which is characterized by fat in the liver, inflammation and cirrhosis, and can progress to cancer. The disease can be more progressive in Hispanics and Pacific Islanders for unknown reasons. Torok’s work in animal models focuses on understanding the role of an enzyme called NADPH oxidase in liver fibrosis, or scarring, associated with the disease.
Reduced nicotinamide adenine dinucleotide phosphate oxidase 2 plays a key role in stellate cell activation and liver fibrogenesis in vivo
Liver fibrosis causes down-regulation of miRNA-150 and miRNA-194 in hepatic stellate cells and their over-expression causes decreased stellate cell activation
Studying the biologic basis of disparity in liver cancer survival among Asian-Americans; why Chinese and Vietnamese have better survival rates than Laotian and Hmong
Christopher Bowlus, professor and chief of the Division of Gastroenterology and Hepatology, is working to understand why Laotian and Hmong individuals infected with the Hepatitis B virus (HBV) — the principal risk factor for liver cancer among Asian-Americans – have higher mortality rates than HBV-infected Chinese and Vietnamese. Using next-generation sequencing technologies, Bowlus is studying viral factors and immune responses in Asian-Americans affected by the cancer, which he believes may cause an earlier onset and more aggressive form of liver cancer in this population. An improved understanding of the biological basis of the disparity may lead to better risk stratification and tailored treatments.
A genetic connection explains why women of Latin-American descent have lower risk of breast cancer
Collaborating with an international team of scientists led by genetics researchers at University of California in San Francisco, Luis Carvajal-Carmona, head of a cancer genomics laboratory at UC Davis, has identified a gene that protects many women of Latin-American descent from breast cancer. Carvajal-Carmona and his team validated the effect of the protective variant in South America, where they found the gene decreased the risk of breast cancer by nearly 50 percent. Women with one copy of the variant were about 40 percent less likely to have breast cancer. Women with two copies of the variant doubled their protection to 80 percent. Carvajal-Carmona and his colleagues are now leading a similar study in South America and expect to report results early next year.