The impact of sex on ropporin expression in multiple myeloma patients

Background: Multiple myeloma (MM) is a cancer of plasma cells wherein aberrant cells accumulate in the bone marrow leading to bone damage and interference with normal blood cell production. Although MM remains incurable, it is treatable. As with most forms of cancer, early detection is the key to improving prognosis and avoiding permanent damage. Cancer Testis Antigens (CTAs) are a class of proteins that are expressed in male gametogenic tissue but generally not in the somatic tissue of healthy adults. However, a number of cancer types have been shown to produce these proteins, and their expression has been correlated with malignancy. Ropporin is a specific CTA shown to be associated with MM, and this protein represents a potential target for MM diagnosis as well as immunotherapy. In this study, we examine the impact of sex on the expression of Ropporin, in MM patients. Methods: The expression of this particular CTA in MM patients was analyzed using PCR, ELISA, and immunohistochemistry in a cohort of 59 MM patients (37 male and 22 female). Results: 61% of MM patients were positive for Ropporin expression. When the data were broken down by sex, it was revealed that Roporrin expression was 81.8% in females and 48.6% in males. Interestingly, 50% of female patients as well as 78% of males expressing Ropporin were deceased. In addition, 100% of the deceased subjects in the cohort were Ropporin positive. Conclusions: Our results provide indications that sex can shift the expression of CTA in multiple myeloma. Furthermore, the data indicate CTA expression may affect the prognosis in MM patients. Further studies in a large cohort of patients are warranted to validate the correlation of CTA/ropporin in MM patients and sex.