A light and electron microscopic histochemical study on lectin binding to cells with high metastatic potential in Lewis lung carcinoma.

Lectin binding to tumor cells in tissue sections of nonmetastatic and metastatic murine Lewis lung carcinoma (LLC) was assessed by light and electron microscopy using a lectin-gold technique. Ulex europaeus agglutinin-I (UEA-I) and peanut agglutinin (PNA) showed no binding, whereas concanavalin A (Con A), soybean agglutinin (SBA), Dolichos biflorus agglutinin (DBA), Maclura pomifera agglutinin (MPA), and Ricinus communis agglutinin-I (RCA-I) bound equally to the transplanted sites and metastases. However, wheat germ agglutinin (WGA) bound to metastases more highly than to the transplanted sites and there was a statistically significant difference (P less than 0.01) between the transplanted sites and metastases with regard to pre-embedding method. The tumor cells binding to WGA clearly decreased in number after sialic acid pretreatment and were rich in more well-differentiated organelle. In the bromodeoxyuridine (BrdUrd) labeling in vivo, cell proliferation was greater in the metastatic sites than in the transplanted sites. The above findings suggest that glycoconjugates on the tumor cell surface are altered in the process of metastasis and correlate with metastatic potential and cell proliferation.