3324

HSP90AA2P

heat shock protein 90kDa alpha (cytosolic), class A member 2, pseudogene;HSP90AA2P;heat shock protein 90kDa alpha (cytosolic), class A member 2, pseudogene

heat shock 90kD protein, alpha-like 3|heat shock 90kDa protein 1, alpha-like 3|heat shock protein 86|heat shock protein 90kDa alpha (cytosolic), class A member 1 pseudogene

11p14.1

pseudo

PURPOSE: We studied whether HSP90alpha was associated with the special carbohydrate structures IMH-2 epitopes, and investigated its mRNA expression and clinical relevance in colorectal cancer (CRC) patients. METHODS: The lysates and the culture media of colon cancer HCT-8 cells were immunoprecipitated with IMH-2 antibody, and the immunoprecipitates were subsequently analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or by immunoblotting with anti-HSP90alpha antibody. In vitro wound-healing assay was done to evaluate the role of IMH-2 epitope-associated HSP90alpha in HCT-8 cell migration. Real-time RT-PCR was performed to detect the levels of HSP90alpha mRNA expression in paired tumor and non-tumor tissues of 56 CRC patients. The correlation of tumor HSP90alpha mRNA overexpression with CRC metastasis and poor survival outcome was determined by statistical analyses. RESULTS: HSP90alpha was first identified as an IMH-2 epitope-associated protein by immunoprecipiation, mass spectrometry, and immunoblotting analysis. IMH-2 epitopes were detected in both cellular and secreted HSP90alpha. HCT-8 cell migration induced by serum starvation-conditioned medium was blocked by anti-HSP90alpha antibody or the HSP90alpha inhibitor geldanamycin (GA) as efficient as by IMH-2 antibody, suggesting that IMH-2-associated HSP90alpha was involved in serum starvation-induced CRC cell migration. On the other hand, HSP90alpha mRNA expression was induced in HCT-8 cells after serum starvation. Clinically, 15 (26.8%) of 56 CRC patients exhibited tumor HSP90alpha mRNA overexpression and had higher rates of metastatic occurrence (P = 0.003) and poor prognosis (P = 0.028). CONCLUSIONS: HSP90alpha was an IMH-2 epitope-associated protein. tumor HSP90alpha overexpression was correlated with the metastasis and poor prognosis of CRC patients.