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In our previous experiments in Syrian hamsters the in vivo semiquantitative method of determination of the natural resistance-depressing (NRD) activity of tumor cells was described. It was demonstrated that inactivated cells of different tissue culture cell lines derived from in vivo tumors in contrast to normal, or in vitro spontaneously transformed hamster embryo (STHE) cells, bear the NRD factor. It was suggested that NRD activity of tumor cells might be essential for the development of primary tumors and metastases (Deichman et al., 1979). Therefore, in this study we compared the NRD activity and metastatic activity (MA) of the parental STHE cells never passaged in vivo and STHE in vivo sublines, obtained from subcutaneous tumor nodules and from individual spontaneous lung metastases (LM) after s.c. transplantation of STHE cells. Five LM sublines of STHE strain (out of eight investigated) were NRD active as well as the cells of one of two s.c. tumor nodules. Study of MA, i.e. the relation between the number of cells inoculated retroorbitally in the bloodstream of hamsters and the number of experimental metastases developed in the lungs of inoculated animals, demonstrated that the highest MA was observed with the cells of LM sublines possessing the highest NRD activity. Parental STHE cells did not depress natural anti-tumor resistance and their MA was the lowest. The data presented demonstrate the heterogeneity of the population of constantly cultured in vitro STHE cells in relation to their NRD activity and the selection of NRD active cells during the development of lung metastases.
G I Deichman, and
T E Kluchareva, and
L M Kashkina, and
V A Matveeva, and
E L Vendrov, and
V I Zemtsova
November 1981,
Biulleten' eksperimental'noi biologii i meditsiny,
G I Deichman, and
T E Kluchareva, and
L M Kashkina, and
V A Matveeva, and
E L Vendrov, and
V I Zemtsova
March 1986,
International journal of cancer,
G I Deichman, and
T E Kluchareva, and
L M Kashkina, and
V A Matveeva, and
E L Vendrov, and
V I Zemtsova
January 1998,
Cancer detection and prevention,
G I Deichman, and
T E Kluchareva, and
L M Kashkina, and
V A Matveeva, and
E L Vendrov, and
V I Zemtsova
January 1988,
Clinical & experimental metastasis,
G I Deichman, and
T E Kluchareva, and
L M Kashkina, and
V A Matveeva, and
E L Vendrov, and
V I Zemtsova
August 1981,
The Journal of general virology,
G I Deichman, and
T E Kluchareva, and
L M Kashkina, and
V A Matveeva, and
E L Vendrov, and
V I Zemtsova
October 1997,
Biochemistry and molecular biology international,
G I Deichman, and
T E Kluchareva, and
L M Kashkina, and
V A Matveeva, and
E L Vendrov, and
V I Zemtsova
October 1974,
Differentiation; research in biological diversity,
G I Deichman, and
T E Kluchareva, and
L M Kashkina, and
V A Matveeva, and
E L Vendrov, and
V I Zemtsova
January 1981,
Advances in experimental medicine and biology,
G I Deichman, and
T E Kluchareva, and
L M Kashkina, and
V A Matveeva, and
E L Vendrov, and
V I Zemtsova
January 1988,
Eksperimental'naia onkologiia,
G I Deichman, and
T E Kluchareva, and
L M Kashkina, and
V A Matveeva, and
E L Vendrov, and
V I Zemtsova
March 1980,
International journal of cancer,
