bcl-2 and p53 Protein Expression in Multiple Myeloma and Non-tumorous Plasma Cells A study related to survival

Kang, Yu Na; Park, Kwan Kyu; Kwon, Kun Young; Lee, Sang Sook; Chang, Eun Sook; Lee, Young Jae

Abstract

The gene product of bcl-2 (B-cell leukemia/lymphoma-2) was suggested to suppress programmed cell death (apoptosis) of tumor cells and be involved in the development of multiple myeloma. However, the normal plasma cells also express the protein. It is unclear whether the expression of bcl-2 in multiple myeloma is of normal character or of regulatory adaptation in association with neoplastic transformation. p53 was also suggested to be involved in tumor progression since mutations on p53 were found in multiple myeloma. In order to find the relationship between the expression patterns of bcl-2 and p53 in tumor cells of multiple myeloma and non-neoplastic plasma cells, we examined 38 cases of multiple myeloma and 10 cases of nasal polyp immunohistochemically. Furthermore, expression of bcl-2 and p53, mitosis, clinical stage and infiltrative pattern of tumor cells in bone marrow were also evaluated in association with the survival of patients. By immunostaining with anti-bcl-2 and p53 monoclonal antibody, 37 out of 38 cases of multiple myeloma and all of 10 cases of nasal polyp were positive for bcl-2 but only 7 cases of multiple myeloma were positive for p53. Marked dysplasia, low percentage of bcl-2 expression, and increased mitoses were correlated with poor prognosis. Based on these observations, we suggest that bcl-2 and p53 are involved in tumorigenesis of multiple myeloma and the survival of patients would be influenced by dysplastic change, mitosis and degree of bcl-2 expression.