Overexpression of metastasis-associated in colon cancer 1 in retinoblastoma

Introduction: Metastasis-associated in colon cancer 1 (MACC1), one of the prognostic markers for colonic and other tumours was noted to be overexpressed in retinoblastoma (Rb) Y79 cancer stem cells. This prompted us to evaluate its expression in primary Rb tumour and serum samples with clinicopathologic correlation. The interacting partner, c-MET was also evaluated in primary tumour tissues to explore the activation of MACC1 signaling. Methodology: This study was done following institutional review board approval from participating institutes. Semiquantitative gene expression for MACC1 was evaluated using formalin-fixed paraffin-embedded sections and unfixed tumour samples from primary Rb cases ( n = 44). Immunolocalization for MACC1 was assessed in primary Rb tumours ( n = 22), bone marrow aspirates with metastasis ( n = 3), and c-MET expression was also assessed in Rb tumours ( n = 17). Serum MACC1 levels were analysed using enzyme-linked immunosorbent assay in samples collected from Rb patients undergoing enucleation ( n = 31), Rb patients with proven clinical metastasis ( n = 3), and compared to appropriate controls. Clinicopathologic correlation of MACC1 expression was analysed using the medical records with specific reference to histologic risk factors (HRF) for metastasis and differentiation. Results: High expression of MACC1 gene was noted in all the tumour samples ( n = 44), more so in cases with versus without HRF ( p