Affiliations: Department of Preclinical Research and Epidemiology,
Centro Riferimento Oncologico, IRCCS, Aviano (PN), Italy | Department of Medical Oncology, Centro Riferimento
Oncologico, IRCCS, Aviano (PN), Italy | Department of Surgical Oncology, Centro Riferimento
Oncologico, IRCCS, Aviano (PN), Italy | Department of Diagnostics, Centro Riferimento
Oncologico, IRCCS, Aviano (PN), Italy | Department of Experimental Medicine and Pathology,
University La Sapienza, Rome, Italy
Note: [] Corresponding author: Alessandra Viel, PhD, Department of
Preclinical Research and Epidemiology, Centro Riferimento Oncologico, IRCCS,
Aviano (PN), Italy. Tel.: +39 0434 659671; Fax: +39 0434 659659; E-mail:
[email protected]
Abstract: Aim of this study was verifying whether mucin producing colon
cancers (CRCs) could develop through a molecular pathway involving
microsatellite instability (MSI) and MUC gene alterations. Out of 49 CRCs
expressing variable amounts of mucin, 22 (44.9%) were MSI-H and 5 (10.2%)
were MSI-L. MUC genes were analyzed by Southern blotting and extra bands
were evident in the Variable Number Tandem Repetition (VNTR) regions of
MUC2 (5 cases) and MUC5AC (2 cases), but not MUC1 and MUC4
genes. Since the somatic VNTR abnormalities were detected in 6 MSI-H and in 1
MSI-L tumors, they seem to be peculiar of mismatch repair defective CRCs. Our
finding suggests that alteration and/or loss of structurally normal MUC
genes may be an important step in the neoplastic molecular pathway of a subset
of CRCs and that mutations involving VNTR repetitive sequences may exist in MSI
tumors as a direct and/or indirect consequence of an inefficient MMR
system.
