The Eca-109 cell line (human cancer cell line of the esophagus) and CHO cell line (Chinese hamster ovary cell line) were used in the present experiment. Three groups of the fusion cells induced by PEG were obtained. These groups were: (1) the cells formed by the fusion of Eca-109 and Eca-109. (2) the fusion of CHO and CHO. (3) the hybrids of Eca-109 and CHO. The third group was demonstrated by autoradiography after incorporated H~3-thymine. The results indicate that the number of megalonucleated cells increases more and more, while the number of multinucleated cells gradually decreases in 10 days after the treatment by PEG in all groups.The forms of fusion cells of Eca-109 and Eca-109 or CHO and CHO similar to those of parent cells. Heterogeneous binucleated cells have the same form as one of parent ceils or as transitional form between two parent cells. The multinucleated cells have various shapes.Histochemical observations have shown that reactions of lactate dehydrogenase (LDH), glutamate dehydrogenase (GDH), malate dehydrogenase (MDH) in the fused cells were stronger than mononucleated cells. The level of activity of nonspecific esterase (NSE) in heterokaryon was intermediate between two parent cells i.e. higher than CHO and lower than Eca-109.

Objective To investigate the effect of tadpole extract(T871 3) on tumor cells and its mechanism. Methods We studied the effects of T871 3 on proliferation, differentiation and apoptosis of HL 60 cells by cytomorphological observation, cytochemistry and TUNEL method. We also examined gene expression during the induction of apoptosis and differentiation in tadpole extract treated HL 60 cells by in situ hybridization and intact cell mRNA dot blot techniques. Results 1 T871 3 was able to inhibite HL 60 cells proliferation. 2 T871 3 was able to induce HL 60 cells to differentiate along monocyte macrophage lineage at low concentration, and apoptosis at higher concentration. 3 The differentiation of HL 60 cells was accompanied by downregulations of c myc,c myb gene expression, The apoptosis of HL 60 cells was accompanied by downregulations of c\|myc bcl 2 gene expression, suggesting that these genes may be involved in the apoptosis and differentiation process. Conclusion Tadpole extract may have effects on HL 60 cells through changing the oncogene expression. [

The tadpole extract without large molecular protein(T-871) was prepared from dry tadpoles. This extract and RPMI1640 medium were mixed in the ratio of 1:50(V/V) to form T-871 medium. HeLa cells were cultured in the T-871 medium in order to study the possible mechanism of HeLa cell differentiation induced by tadpole extract. We found that there was a decreased acitivity of LDH which may be released through HeLa cell membrane in the 2 day's cultured T-871 medium. After 3 day's culture in the T-871 medium we found that on the HeLa cell membranes, Na-K-ATPase activity reduced and the content of Con A receptors increased. When these cells were analyzed by flow cytometry(FACS-420), the results indicated that HeLa cells accumulated in G_2 and M phases of the cell cycle and the influence on DNA and RNA content of the HeLa cells was insignificant. HeLa cells cultured by RPMI 1640 medium or T-871 medium for 3 days were inoculated into the dorsal hypodermis of 12 nude mice, respectively. Then after 24 hours this extract was injected to each nude mouse at dose of 0.3 ml each day. Our study showed that T-871 could result in decrease of tumor formation such as delay of tumor nodule appearance and reduce of tumor weight. This study suggested that the changes of the cell membrane may be caused by the tadpole extract. It may also reduce malignancy of the HeLa cells.