Study: miR-34b gene associated with aggressive form of melanoma

Keck Graduate InstituteOct 14 2011

A certain microRNA gene, miR-34b, could be a useful biomarker in early diagnosis of the most lethal forms of melanoma, according to new research published by KGI Professor Animesh Ray and his research collaborators.

Ray, together with Dr. Ranjan Perera, an associate professor at the Sanford Burnham Medical Research Institute in Orlando, Florida, spent nearly five years identifying microRNA molecules (a kind of non-coding RNA recently implicated as important gene regulatory agents) and their genes, which could signal whether tumors may develop into aggressive cancers.  

Their paper, "Epigenetic Regulation of MicroRNA Genes and the Role of miR-34b in Cell Invasion and Motility in Human Melanoma," was published recently in the scientific journal PLoS One.

"There are no good molecular markers that a physician can look at to determine whether a particular skin tumor is invasive or not," notes Ray, who serves as KGI's faculty chair as well as director of the PhD program and the Center for Network Studies. "After one develops an aggressive form of melanoma, which metastasizes in different tissues, there is no targeted chemotherapy."

Melanoma, the most serious type of skin cancer, accounted for nearly 70,000 cases of skin cancer last year and most of the nearly 12,000 deaths, according to the American Cancer Society. Melanoma has complex origins, influenced by genetic predisposition, prolonged exposure to ultraviolet rays of the sun and the extent of melanin pigmentation of the skin.

Perera and Ray evaluated, at a molecular level, the difference between normal skin cells and cancer skin cells. They also analyzed the different properties of cell lines taken from a skin cancer patient's primary tumor and lymph glands, where the invasive cancer had spread.

Ray has received funding from the National Science Foundation and the National Institutes of Health, while Perera secured funding from the Sanford Burnham Medical Research Institute.

Further research would involve identifying additional microRNA genes related to melanoma. In highly controlled experiments, the researchers would implant human melanoma cells into specially manufactured mouse strains to determine if they could alter the microRNA genes to reverse aggressive melanoma, Ray says.