Scientists say that they have discovered two blood-borne markers that are involved in prostate cancer in African-American men. African Americans are typically diagnosed with prostate cancer more frequently and later than any other ethnic group in the U.S. (Obesity may be one possible explanation of this), making a screening technique based on these markers very important.
In addition, to their role as potential screening targets, these proteins play a role in chemical pathways that control disease progression, according to the scientists.
The researchers compared prostate cancer cells from 50 African-American and Caucasian men, aged 50 to 60, matched so that each group comprised similar tumor grades.
Using DNA sequencing and screening techniques, they found that heterogeneous nuclear ribonucleoprotein H1 (hnRNP-H1) and scaffold attachment factor B2 (SAFB-2), which both comprise a part of the nuclear matrix, are overproduced in 90% of tumor cells from African Americans. They also demonstrated that these proteins have increased production in African-American men as opposed to Caucasians.
Additional investigation into the pathways that these proteins activate suggested a controlling role in how prostate cancer advances, the researchers report.
“Both of these genes share many structural and functional similarities including possession of mRNA binding sites that could allow them to regulate how other genes are read from the DNA,” explains Asim B. Abdel-Mageed, Ph.D., associate professor and director of the molecular oncology research program in the department of urology at Tulane University School of Medicine.
The researchers further determined that hnRNP-H1 protein binds to and activates the androgen receptor (AR). Similarly, SAFB-2 was shown to have a role in regulation of hormone-related genes.
“Based on this data, we believe their selective expression may represent a novel mechanism for disease progression and development of hormone-refractory disease in African Americans,” adds Dr. Abdel-Mageed, who presented the results at the American Association for Cancer Research conference on “The Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved”.