[The expression of PCNA and NOR in carcinogenesis procession of hamster buccal pouch mucosa].
OBJECTIVE
To investigate the expression of proliferating cell nuclear antigen (PCNA) and nucleolar organizer regions (NOR) with the carcinogenesis model of hamster buccal pouch mucosa.


METHODS
48 Syrain hamsters with 6-8 weeks old and 70-80 g weight were selected. The material used for inducing cancer is 0.5% DMBA (7,12-dimethylbenzanthracene) in acetone. 0.5% DMBA was applied in the right buccal pouch of the hamster 3 times a week for 12 weeks. The control received no treatment. The time for collecting specimens was 3, 6, 9 and 12 weeks. The specimens were immediately fixed with 10% formalin, dyed with HE, and then two doctors major in histopathology evaluated with the WHO criterion (1986). The wax of immunohistochemical specimen was cut and placed on the APES pieces of glass, treated with 50 degrees C for 2 hours and preserved under the indoor temperature. The PCNA was examined with the LSAB technique of immunohistochemistry. The company called Zymed provided the MonAb. The positive control was a sample of human inflammatory hyperplastic lymphoma, and the negative was PBS replacing the MonAb. NOR count was determined in a method of silver nitrate staining. The test condition should be at 45 degrees C without light.


RESULTS
1. AgNOR was usually located in the basal-cell layer of normal epithelium, mainly in a single form. High dysplasia was mainly in an aggregated form, however, carcinoma in infiltration appeared to be in a mixed form. 2. PCNA expression was similar to that of the normal control in hyperplastic epithelia (3 weeks) at a moderate level in dysplasia epithelia (6-9 weeks). PCNA expressed highly in squamous cell carcinoma. The expression of the PCNA in line with malignant progress became stronger increasingly. The positive cell was perceivable in all epithelia of high dysplasia.


CONCLUSIONS
PCNA has been significantly positive and correlative with AgNOR (r = 0.635, P < 0.001), however, the film of PCNA is much clearer and the practical value is greater.
Lin
M
M
College of Stomatology, West China University of Medical Sciences.
Li
B
B
Zhou
M
M
Duan
K
K
D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D006224:Cricetinae; D005260:Female; D008297:Male; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000473:pathology; D009092:Mucous Membrane / Q000378:metabolism* / Q000473:pathology; D009697:Nucleolus Organizer Region / Q000473:pathology*; D011230:Precancerous Conditions; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis*
D018809:Proliferating Cell Nuclear Antigen