| Colorectal carcinoma is one of the malignant digestivecarcinomas. As other tumors, the mechanism of colorectalcarcinogenesis has not been cleared. The uncontrolled cellproliferation is a symbol of tumor. Being a potent negativeregulator of cell proliferation, transtbrming growth factor- D l(TGF- D l ) plays an important role in inhibiting normalepithelial cell growth. Recent studies shows that loss ofgrowth inhibitory response to TGF- D l may contribute tocancer. The type II receptor of TGF- fi l (T fl R II ) is a majorcomponent in TGF- D l signal transduction, Loss and/ormutation of T D R II gene may disturb this transduction, whichmake cell to uncontrolled growth. C};clinD, is a key protein in(>G, phage of the cell cycle. Its overexpression can shorten theprocess from G, to S phage, thus accelerate cell proliferation.In order to investigate the possible mechanism of co1orectalcarcinogenesis and the clinicopathologic significance of TGF-D l, T D R II, CyclinD, and a parameter of cell proliferation-Ki67 protein expression in colorectal carcinoma, an.immunohistochemical SP method was used to examine theexpression of the four kinds of proteins.Materials and Methods: (1) 56 surgically resectedcolorectal carcinoma samples and 2l biopsies were collected.All the tissues were fixed in l0% neutral fOrmalin andembeded in paraffin. (2) SP immunostaining technique wasused to examine the expression of TGF- D l, T 6 R lI,CyclinD, and Ki67 in colorectal adenomas and carcinomas. (3)The data were analyzed by software SPSSl0.0. x 2--test wasused to compare difference between groups. A difference wasconsidered significant if the P value was below 0.05.Results: (l) In normal colorectal mucosa, colorectaladenoma and carcinoma, the positive rates of TGF- P l proteinwere 0%, 28.6% and 57. 1% respectively. There weresignificant differences (P<0.05) between colorecta1 carcinomagroup and the other two groups. The positive rates of T D R IIprotein in above three groups were 95.0%, 90.5% and 5l .8%7respectively. There were significant differences (P<0.05)when colorectal carcinoma group compared with groupsseparately. There were no expression of CyclinD, protein innormal colorectal mucosa. The positive rates of CyclinD, incolorecta1 adenoma and carcinoma were 38. l %, 33.9%respectively. There were signitlcant difference betweennormal mucosa and the other two groups, but no significantdifference between colorecta1 adenoma and carcinoma group.The positive rates of Ki67 protein in normal colorectalmucosa, colorectal adenoma and carcinoma group were 5%,38.l% and 4l. l% respective1y. There were significantdifference (P<0.05) when colorectal adenoma and carcinomagroup compared with normal mucosa group separately, but nosignificant difference between the two groups.(2) In highly, moderately and poorly differentiatedcolorectal carcinomas, the positive rates of TGF- P l proteinwere 57. l%, 48. l% and 73.3% respectively. There were nosignificant difference between these groups. The positiverates of T 0 RII protein had the tendency to decrease withpoor histological grade, 64.3%, 5l .9% and 40.0% respectively,but there were no significant difference between these groups.No significant difference (P>0.05) of the expression ofCyc1inD, and Ki67 protein were tbund among these groupswhen comparison were made.8(3) According to the infiltrating depth of colorectalcarcinoma, 56 cases of colorectal carcinoma were divided intomucosa or submucosa infiltration group and muscular orwhole layer infiltration group. The positive rates of TGF- D lprotein were 30.8% and 65. l % respectively; the positive ratesof T D R II protein were 76.9% and 44.2% respectively. There..were significant difference (P<0.05) between the infiltrationdepth and the expression of TGF- D l and T D R lI. Thepositive rates of CyclinD, protein were 38.5% and 32.6%respectivel...
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