Expression of mucin core proteins, trefoil factors, APC and p21 in subsets of colorectal polyps and cancers suggests a distinct pathway of pathogenesis of mucinous carcinoma of the colorectum.
Mucin core proteins are expressed in a tissue and cell type specific manner in the normal gastrointestinal tract. Aberrant expression of mucin core proteins have been reported in colorectal neoplasms. To examine the relationship between subsets of colorectal polyps and non-mucinous and mucinous adenocarcinomas of the colorectum, we evaluated the frequency of the expression of cell lineage associated mucin core proteins (MUC5AC and MUC2), trefoil factors (TFF1 and TFF3), and APC and p21 in these tissues. An immunohistochemical study was performed in 10 normal rectal mucosa samples (NM) 21 hyperplastic polyps (HP), 20 serrated adenomas (SA), 25 tubular adenomas (TA), 13 tubulovillous adenomas (TVA), 7 villous adenomas (VA), 42 non-mucinous colorectal cancers (NMC), and 19 mucinous colorectal cancers (MC). A higher frequency of ectopic expression of gastric foveolar mucin, MUC5AC, and the expression of intestinal goblet cell mucins, MUC2, was observed respectively in HP (100%, 100%), SA (85%, 85%), TVA (85%, 85%), and VA (100%, 100%), compared to TA (32%, p<0.002; 36%, p<0.01). MC (68%, 100%) also showed a higher frequency of the expression of MUC5AC and MUC2 compared to NMC (31%, p=0.001; 38%, p<0.001), and TFF1 showed similar patterns of expression. APC protein and p21 were also expressed at a higher frequency in HP (100%, 100%), and SA (67%, 83%), than in TA (29%, p<0.03; 46%, p<0.05). MC (68%, 100%) showed a higher frequency of expression of APC protein and p21 than NMC (19%, p<0.001; 45%, p<0.01). Our results showed that MUC2 expression and de novo ectopic expression of MUC5AC and TFF1 are more frequent in HP, SA, TVA, VA, and MC than in TA and NMC. These results suggest that simultaneous activation of differentiation pathways of goblet cells and gastric foveolar cells may occur predominantly in the pathogenesis of HP, SA, TVA, VA, and MC, while the pathogenesis of TA and NMC are less likely to involve these processes.
Kim
Dong Hoon
DH
Gastrointestinal Research Laboratory, Department of Veterans Affairs Medical Center, San Francisco, CA 94121, USA. youngk@itsa.ucsf.edu
Kim
Jong Woo
JW
Cho
Joong Hyeon
JH
Baek
Sun Heum
SH
Kakar
Sanjay
S
Kim
Grace E
GE
Sleisenger
Marvin H
MH
Kim
Young S
YS
D000230:Adenocarcinoma / Q000378:metabolism*; D002288:Adenocarcinoma, Mucinous / Q000378:metabolism*; D000236:Adenoma / Q000378:metabolism; D025601:Adenomatous Polyposis Coli Protein / Q000096:biosynthesis*; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D019070:Cell Lineage; D002467:Cell Nucleus / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D003593:Cytoplasm / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D055271:Mucin 5AC; D055262:Mucin-2; D009077:Mucins / Q000737:chemistry* / Q000378:metabolism; D010455:Peptides / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras) / Q000096:biosynthesis*; D000071163:Trefoil Factor-1; D000071165:Trefoil Factor-3; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
D025601:Adenomatous Polyposis Coli Protein; C524625:MUC2 protein, human; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D055262:Mucin-2; D009077:Mucins; D010455:Peptides; C051838:TFF1 protein, human; C082495:TFF3 protein, human; D000071163:Trefoil Factor-1; D000071165:Trefoil Factor-3; D025521:Tumor Suppressor Proteins; D016283:Proto-Oncogene Proteins p21(ras)