Immunohistochemical study of MUC1, MUC2 and MUC5AC in colorectal carcinoma and review of literature.
BACKGROUND
A hallmark of colorectal carcinomas is their ability to secrete mucus. Aberrant expression of mucins and alterations in their glycosylation are associated with the development and progression of malignant diseases. Therefore, mucins can be used as markers of malignancy. Tumor-associated mucins are also used as immunotargets in the treatment of cancer. The present work aimed to study the patterns of expression of MUC1, MUC2 and MUC5AC in colorectal carcinoma using immunohistochemistry and their relationship with site, histological differentiation and stage.


METHODS
Fifty cases of colorectal carcinoma were chosen for the study. The histopathology slides were reviewed and blocks were retrieved. Using manual method, tissue microarray blocks were prepared. Immunostaining for MUC1, MUC2 and MUC5AC was performed on slides cut from the tissue microarray block.


RESULTS
We found that MUC1 expression was upregulated to 39 %, MUC2 expression was downregulated to 43 % and MUC5AC was aberrantly expressed in 24 % of colorectal cancer (CRC). There was a significant correlation between MUC1 positivity and tumor differentiation. As the grade increased from well to moderately differentiated, MUC1 expression increased from 1﻿1 % to 55 % (p-value 0.01). There was a statistically significant difference between MUC5AC positivity and grade of tumor (p-value 0.006). The percentage of cases showing MUC5AC expression increased as the stage of disease progressed from 1 to 4. However, there was no significant difference in MUC5AC positivity and stage of CRC (p-value 0.77).


CONCLUSIONS
We do not find any correlation between tumor stage or site and MUC1, MUC2 or MUC5AC expression. MUC1and MUC5AC expression showed significant correlation with tumor grade.
Department of Pathology, Smt. Kashibai Navale Medical College and General Hospital, Off Katraj Bypass Highway Flyover, Narhe, Ambegaon, Pune, 411 041, India.
Mrunal V
MV
Kesari
Vandana L
VL
Gaopande
Avinash R
AR
Joshi
Shreedhar V
SV
Babanagare
Bageshree P
BP
Gogate
Ameya V
AV
Khadilkar
D000230:Adenocarcinoma; D014408:Biomarkers, Tumor / Q000032:analysis*; D002471:Cell Transformation, Neoplastic; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D055271:Mucin 5AC / Q000032:analysis*; D018396:Mucin-1 / Q000032:analysis*; D055262:Mucin-2 / Q000032:analysis*; D060787:Neoplasm Grading
D014408:Biomarkers, Tumor; C060192:MUC1 protein, human; C524625:MUC2 protein, human; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D018396:Mucin-1; D055262:Mucin-2