Metallopanstimulin is overexpressed in a patient with colonic carcinoma

Background: Human metallopanstimulin (MPS-1) is a 9.4-kDa multifunctional ribosomal S27 / nuclear 'zinc finger' protein which is expressed in a wide variety of actively proliferating cells and tumor tissues. In this paper, we present a case of overexpression of MPS-1 in colon cancer tissues of a seventeen year old male. Methods: Biopsies at the anastomosis and adjacent normal colonic mucosa were obtained by colonoscopy twelve months after right hemicolectomy for an ascending colon well differentiated adenocarcinoma. Immunohistochemical localization of MPS-1 protein was performed by using specific anti-MPS-1 antibodies directed against the N-terminal region of this protein. Results: Immunohistochemistry demostrated an overexpression of MPS-1 in colonic mucosa crypts in the samples obtained at the anastomosis. In contrast, no expression of MPS-1 was observed in the adjacent normal mucosa. Histopathology performed with hematoxilin and eosin staining revealed focal crypt distortion and proliferation, but no carcinoma. Conclusions: In this case, the overexpression of MPS-1 was a more definitive evidence of malignant transformation than histology, as demonstrated by the clinical course of the disease. The results support the hypothesis that increased levels of tissue MPS-1 may correlate with a more aggressive behavior of colon malignancy.