Sequential Changes in Aberrant Crypt Foci and Lectin Expression in the Early and Late Stages of DMH-Induced Colon Carcinogenesis in Rats

BACKGROUND/AIMS: The purpose of this study was to investigate the malignant potential of aberrant crypt foci (ACF) by measuring the multiplicity of crypts and lectin expression in the early and late stages of 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis. METHODS: Six-week-old Wistar rats were injected subcutaneously with DMH for 27 weeks. We classified ACF according to the number of crypts per ACF as a few crypts ( or =4 crypts, NC ACF). Immunohistochemistry was used to evaluate lectin expression. RESULTS: In the early stage, FC ACF (590/1,902, 31.0%) occurred more frequently than NC ACF (35/449, 7.8%); whereas in the late stage, NC ACF (176/449, 39.2%) occurred more frequently than FC ACF (324/1,902, 17.0%). The number of ACF peaked at 15 to 20 weeks. The ratio of NC/FC ACF increased gradually during carcinogenesis. The expression of both UEA1 and PNA was higher in NC ACF than FC ACF. Lectin expression increased in the late stage compared with the early stage. CONCLUSIONS: The expression of lectin was higher in NC ACF and ACF in the late stage. Therefore, ACF with higher multiplicities in the late stage may have more malignant potential in DMH-induced colon carcinogenesis.

Significance of Peanut Agglutinin in the Differentiation between Nevocellular Nevus and Malignant Melanoma / 대한피부과학회지

Using peanut agglutinin(PNA), neurarninidase, and avidin-biotin peroxidase com plex(ABC) technique, normal skin specimens, nevocellular nevi, and malignant melanomas were studied, and different PNA binding patterns between nevocellular nevi and malignant melanomas were observed. The results were as follows : 1. In normal skin, except the basement membrane, epidermis and hair follicle epithelium showed a cell membrane staining of PNA after neuraminidase pretreat ment. Sebaceous glands revealed membranous and cytoplasmic staining of PNA, but sweat ducts were not stained. 2. In nevocellular nevi, none of the nevus cells were stained with PNA aftet neuraminidase preteatment. 3. In malignant melanomas, all of the melanorna cells were stained along the cell mernbrane with PNA after neuraminidase pretreatment. Therefore, the PNA staining after neuraminidase pretreatment on paraffin embedded sections using ABC technique is considered to be a useful probe for the differentiation between malignant malanoma and nevocellular nevus.

Peanut Agglutinin Binding Activity in Overian Malignant Mucinous Tumors

The positive binding activity of lectin, peanut agglutinin (PNA), against the mucinous malignancies of the ovary was studied in order to clarify biologic differences among those lesions using immunoperoxidase method (ABC). A total of 23 cases were included in this study and they were classified as 10 cases of mucinous cystadenocarcinoma, 9 mucinous tumors of borderline malignancy and 4 pseudomyxoma peritonei, histologically. Nine of 10 cystadenocarcinomas and all cases of pseuomyxoma peritonei showed more than moderate degree of positive binding activity (>2+) with PNA in the neoplastic epithelial cells. In the cases of borderline malignancy, only 3 of 9 revealed as much similar binding pattern with PNA as cystadenocarcinoma group, in contrast, minimal degree of positivity (1+) was noted in the remainder. These findings may suggest heterogeneity in the biochemical characteristics among the cases of borderline lesion. And it is proposed that the higher PNA binding cases in ovarian mucinous borderline malignancy require extensive sampling by multiple sections and further careful follow-up study.

The Study of Peanut Aggiutinin Receptor in Human Pancreatic Cancer / 第二军医大学学报

This histochemical binding of horseradish peroxidase labeled peanut agglutinin (HRP?PNA) to paraffin sections of 18 cases of pancreatic cancer was investigated with 5 case of normal pancreas and 8 pancreatitis as the control. The PAN receptor was not found in the normal pancreas, but it appeared in 15 cases of pancreatic cancer (82%). Three cases of pancreatitis presented positive stainings of PNA binding (37%). There were 3 kinds of PNA binding forms: (1) linear distribution along the gland of carcinoma cells; (2) round staining with the ductal epithelium; and (3) diffuse scattering with an increased dot staining. There was a good relationship between the staining degree and cell differentiation. The positive staining increased when the cell was transformed from inflammation to carcinogenesis, and decreased from well differentiation to poorly differentiation.