Analysis of novel collectin, CL-K1 function in colorectal cancer

2010 Fiscal Year Final Research Report

• Project/Area Number: 21790640
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: Gastroenterology
• Research Institution: Asahikawa Medical College
• Principal Investigator: MOTOMURA Wataru Asahikawa Medical College, 医学部, 助教 (70374791)
• Project Period (FY): 2009 – 2010
• Keywords: コレクチン / 大腸癌 / 腫瘍マーカー

Research Abstract

The present study aimed to determine CL-K1 expression in tumourigenesis of human gastrointestinal (GI) malignancies. We examined CL-K1 distribution in normal human and cancer tissues by using tissue arrays. We also examined CL-K1 distribution in stomach and colorectal tissue and performed immunohistochemical analyses to determine its expression in epithelial and connective tissues. Real-time PCR and immunohistochemical analyses demonstrated that CL-K1 expression in humans resembles that in mice, and in human cancer tissues, CL-K1 expression tends to be elevated. Our examination of 42 human gastric tissues showed that CL-K1 protein expression was frequently observed in gastric cancer tissues compared with that in adjacent normal mucosa. In addition, in 98 human colorectal tissues, CL-K1 expression showed a significant gradual increase with progression to malignancy. Moreover, CL-K1 expression tended to be higher in invasive cancer tissues than in non-invasive cancer tissues. CL-K1 was expressed in the proximal tubules in the kidneys, vascular portion of several organs, hepatocytes in the liver, and mucosa in the gastrointestinal tract. It is of interest that the CL-K1 expression profile in humans is similar to that in mice. In a study of 140 speciments of GI tract tissues, CL-K1 up-regulation correlated with malignancy. Together, these histological and pathological findings may be useful in furthering our understanding of biological functions in cancer tissues.