Lectins are proteins and glycoproteins that bind specifically to mono or oligosaccharides and are found primarily in plants. Since they are available commercially in pure from and their interactions can be inhibited and even reversed by simple sugars, Lectins have been extensively used as probes of the structure and organization of cell membrane carbohydrate-containing components. Biotinylated 8 plant Lectins-concanavalin A (Con A), peanut agglutinin (PNA), Ricinus communis agglutinin I (RCA I), Ulex europaeus agglutinin I (UEA I), soybean agglutinin (SBA), Dolichos biflorus agglutinin (DBA), wheat germ agglutinin (1VGA) and Pinellia ternata agglutinin (PTA)-were bound to paraffin sections of surgically resected human testicular tumors and visualized with avidin-horseradish peroxidase conjugates. The testicular tumors used were seminomas, embryonal carcinomas, teratocarcinomas and Leydig cell tumors with the contrast of normal testicular tissues.
The results obtained are as followings:
1. In the normal testicular tissues Con-A, and RCA I showed positive reactions with the spermatocytic cells and PNA showed positive reaction with the secondary spermatocytes and spermatozoa.
2. On the Leydig cells, in normal testicular tissue or Leydig cell tumors, Con-A, WGA, UEA I and PTA revealed positive cytoplasmic reactions.
3. All the Lectins used exhibited negative reactions on the neoplastic cells of seminomas. However, Con-A showed positive cytoplasmic reactions on the seminomatous components of teratocarcinomas.
4. Con-A and PTA showed positive cytoplasic reactions on the glandular components of embryonal carcinoma and SVGA revealed linear positive reaction on the poorly differentiated cells of embryonal carcinomas.
5. Con-A and PTA showed granular positive reactions on the syncytiotrophoblasts in choriocarcinomatous components of teratocarcinomas.
6. WGA and RCA I exhibited iinear positive I-eactions on the neoplastic cells of endodermal sinus tumors. And Con-A showed positive reactions on the hyaline bedies of the tumors.
With the above results, there are changes in lectin receptors in the cell membranes either loss or acquire, between normal cells and neoplastic cells.
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