The Assessment Of The Expression, Consequence Of PTEN, FHIT Protein And Their Relation With PCNA, P53 In Colorectal Carcinoma

Objective: (1)To observe the expression of carcinoma suppressor gene PTEN,FHIT in carcinoma, adenoma and normal mucosa in large intestine .(2)To assess the consequence of PTEN,FHIT in the pathogenesis and development of colorectal carcinoma and the relation of PTEN,FHIT with PCNA ,carcinoma suppressor gene P53.(3)To evaluate if PTEN and FHIT can be used as new marker of diagnosis and prognosis of colorectal carcinoma . Methods: The expressions of PTEN and FHIT were assessed with immunohistochemical S-P method in 64 colorectal carcinoma, 25 adenoma and 19 normal mucosa in large intestine .The relations of expression of PTEN and FHIT with histological classification, Duckes stage and lymph nodes metastases were analysed .The expression of PCNA,P53 and their relation with PTEN,FHIT were assayed.Results: The expression of PTEN was decreased successively from normal colorectal mucosa, adenoma to colorectal carcinoma. Its expression in colorectal carcinoma(48.4%) was significantly lower than in adenoma (80.0%, P<0.01) and in normal colorectal mucosa(94.7% ,P<0.01), lower in stage C and D than in stage A and B (Duckes stage) (P<0.01), lower in lymph nodes metastases group (28.6%) than in non-metastases group(58.1%) (P<0.05). The expression of FHIT in colorectal carcinoma(54.7%) was significantly lower than in adenoma(88.0%, P<0.01) and in normal colorectal mucosa (100.0%, P<0.01). In colorectal carcinoma group, the expression of FHIT was significantly lower in poorly differentiated group than in well and moderately differentiated groups(P<0.05), lower in stage C and D than in stage A and B(P<0.05), lower inlymph nodes metastases group(33.3%) than in non metastases group(65.1%)(P<0.05). In colorectal carcinoma, the expression of PTEN was positively related with that of FHIT(rs=0.317,P<0.05).The expression of PTEN and FHIT were negatively related with that of PCNA (rs=-0.267, P<0.05; rs=-0.374, P<0.01) but not related with that of P53(rs=-0.153, P>0.05; rs=0.078, P>0.05).Conclusions: (l)The negative expression of PTEN or FHIT may have an important role in the pathogenesis and development of colorectal carcinoma. The expression of PTEN and FHIT can be easily detected by immunohistochemical method. So,PTEN and FHIT may be used as a new marker of diagnosis and prognosis of colorectal carcinoma. (2)The expression of PCNA may indicate the proliferation of colorectal carcinoma and may be used as a useful index of proliferation of colorectal carcinoma. The expression of PCNA may be affected by PTEN protein or FHIT protein .The combined assessment of the expression of PTEN or FHIT and PCNA may be helpful for judging the malignancy and prognosis.(3)In colorectal carcinoma, the expressions of native PTEN,FHIT were reduced and that of mutant P53 increased .This further proved that colorectal carcinoma was induced by the cooperation of several tumor suppressor genes.