Hematopoetic neoplasia or clam hemocyte cancer (a leukemia-like disease) has been studied in a number of bivalve molluscs for the last 20 years. Recent molecular studies of the hemocytes of the soft shell clam, Mya arenaria, have demonstrated an interaction between p53 and mortalin, the mitochondrial Hsp70. The former protein is intimately involved in the initiation of cell-cycle arrest, apoptosis, DNA repair, and cell differentiation. In cancerous clams, wild-type p53 is sequestered in hemocyte cytoplasm by mortalin and cannot be translocated to the nucleus. This is critical because although p53 is functions properly, it is unable to enter the nucleus and initiate cell-cycle arrest. This allows the immortality of cancerous clam hemocytes (CCH). In CCH, wild-type p53 can be induced to enter the nucleus and trigger apoptosis genotoxically following treatment with the topoisomerase II inhibitor, etoposide, or non-genotoxically with the dye, MKT-077. Full-length and truncated (missing exon 3) clam variants of human mortalin have recently been cloned.

Here I have generated and purified an antibody to the truncated variant of clam mortalin and have attempted to determine its location within cancerous clam hemocyte cytoplasm.

I point out problems with the transfection of the truncated mortalin antibody into clam hemocyte cytoplasm and in localizing antibodies in cancerous clam hemocytes embedded in water-soluble resins. The results of this study demonstrate localization of truncated mortalin near mitochondria of cancerous clam hemocytes.