[Growth-promoting action of L-cysteine and its related compounds on Ehrlich ascites tumor cells in vitro].
Ehrlich ascites tumor cells (EAT) could not proliferate in a basal medium (BM). L-Cysteine (L-CYS) added to BM in a concentration of 0.5 to 2 mM could promote the growth of EAT. At an unusual concentration of L-CYS (1 mM), the growth-rate was 233% (n = 50) at 72 hr after EAT transplantation. A similar growth-rate was obtained when EAT was transplanted 24 hr after addition of L-CYS to BM, although the free SH content in L-CYS-added BM at this time decreased to the level of that in BM. S-Methyl- and S-benzyl-L-cysteine showed no growth-promoting effect. The metabolic products of L-CYS (L-cysteine sulfinic acid, hypotaurine and taurine) showed a lower effect or none, but L-cystine showed the same activity as L-CYS. The EAT cultured in L-CYS-added BM was found to have an increased intracellular free SH and unchanged protein SH. These findings suggest that L-CYS added to BM is changed in a non-SH compound (possibly L-cystine) that is taken up into the cells and increases the intracellular free SH, resulting in the cell growth promotion.
Takamura
S
S
Department of Pharmacology, Kanazawa Medical University, Ishikawa, Japan.
Yoshida
J
J
Suzuki
S
S
D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism / Q000473:pathology*; D002455:Cell Division / Q000187:drug effects; D003545:Cysteine / Q000031:analogs & derivatives / Q000494:pharmacology*; D003553:Cystine / Q000378:metabolism; D005260:Female; D051379:Mice; D009368:Neoplasm Transplantation; D018377:Neurotransmitter Agents; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013654:Taurine / Q000031:analogs & derivatives / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D018377:Neurotransmitter Agents; D013438:Sulfhydryl Compounds; D013654:Taurine; D003553:Cystine; C003949:hypotaurine; D003545:Cysteine; C013461:cysteine sulfinic acid