Expression of insulin-like growth factor-1 receptor in human colorectal cancer.
The activation of the insulinlike growth factor 1/IGF-1 receptor system (IGF1/IGF1-R) has recently emerged as critical event in transformation and tumorigenicity of several murine and human tumors. Expression of IGF1 and of IGF1-R has been demonstrated in normal and neoplastic intestinal cell lines of rats and humans. However, the modulation of IGF1-R expression during the progression from normal colonic mucosa to adenoma, to carcinoma, and to metastasis, has not been evaluated. In this retrospective study, we investigated the expression of IGF1-R in 12 colonic adenomas (AD), 36 primary colorectal adenocarcinomas (CA), and in 27 corresponding metastases (MT). Normal colonic mucosa (N) was adjacent to the CA in 34 cases. Formalin-fixed, paraffin-embedded tissues of each case were immunostained using the avidin-biotin-peroxidase method. We used an anti-IGF1-R rabbit polyclonal antibody (Santa Cruz Biotechnology, CA; dilution 1:100). Positive staining was quantitated by CAS-200. Moderate to strong cytoplasmic immunostaining was observed in 34 of 36 CA (96%), and in 25 of 27 MT (93%). In all of the positive MTs, the intensity of the staining was always strong. In 10 of 12 ADs (83%), only a faint cytoplasmic stain was identified. Normal mucosa when present was negative. Strong IGF1-R positivity correlated with higher grade and higher-stage tumors (P < .01). These data suggest a role of IGF1-R expression during the progression of colorectal adenoma to carcinoma. An increased number of IGF1-R receptors may favor the metastasis of colorectal cancer.
Hakam
A
A
Department of Pathology, Moffitt Cancer Center and Research Institute, University of South Florida, College of Medicine, Tampa 33612-9497, USA.
Yeatman
T J
TJ
Lu
L
L
Mora
L
L
Marcet
G
G
Nicosia
S V
SV
Karl
R C
RC
Coppola
D
D
D000230:Adenocarcinoma / Q000378:metabolism*; D000236:Adenoma / Q000378:metabolism; D000368:Aged; D000369:Aged, 80 and over; D003106:Colon / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism; D008113:Liver Neoplasms / Q000378:metabolism / Q000556:secondary; D008198:Lymph Nodes / Q000378:metabolism; D008207:Lymphatic Metastasis; D008297:Male; D017526:Receptor, IGF Type 1 / Q000096:biosynthesis*
D017526:Receptor, IGF Type 1