• Biomolecules & Therapeutics
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• 제3권2호
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• pp.122-131
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• 1995

Five human cancer cell lines (HeLa S3, Hep 3B, KATO III, Hs 683, HeLa MR) and one human normal cell line (WI-38) were examined cell viability, northern blot analysis, western blot analysis, and in situ hybridization for the expression $O_{6}$ -methylguanine-DNAmethyltransferase (MGMT), which can repair $O_{6}$ -methylguanine produced in DNA by alkylating agents. In cell viability test, the lethal sensitivities of each strain against anti-tumor drug N,N-bis(2-chloroethyl)- N-nitrosourea (BCNU) were counted, and both BCNU treated and untreated cell extracts were examined for their MGMT inducibility by RNA dot blot analysis. Cell lines did not show MGMT induction by BCNU pretreatment. Tlle MGMT activity was assayed by measuring the $^3$H radioactivity transferred from the substrate DNA containing [methyl-$^3$H)-O$_{6}$ -methylguanine to acceptor molecules in the cell extracts. Extracts from the majority of tumor strains and normal cells contained substantial MGMT activity of varying degree, while the known Mer$^{[-10]}$ cell (lacked or severely depleted in MGMT activity) Hela MR, and Hs 683 (proved to be Mer$^{[-10]}$ ) were much more sensitive to BCNU than the rest of tumor strains, as measured by cell viability test. Overall results above, KATO III showed the highest expression level of MGMT among the strains examined. Furthermore, with all the tumor and normal strains tested, a good correlation was observed between MGMT expression and cellular resistance to BCNU. The varying levels of expression of MGMT in human cancer cells found in this study should provide a molecular basis for MGMT expression among tumor strains from different tissue origin, the information of antitumor agents selection for chemotherapy of cancers.

• 생약학회지
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• 제18권2호
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• pp.127-135
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• 1987

In vitro sensitivity testing was performed for 21 kinds putative anticancer drugs selected from references and information. Cellular damage of P815 mastocytoma cells following exposure to water extracts of drugs was evaluated by colony formation assay. Highly effective drugs with more than 50% inhibition of colony formation were seven (Houttuyniae Herba, Sanguisorbae Radix, Nepetae Herba, Manitis Squama, Lonicerae Flos, Amomi Semen, Polyporus), though not more effective than BCNU. According to the results of $^3H-thymidine$ incorporation assay for determination of selective cytotoxicity, 3 of these drugs (Houttuyniae Herba, Polyporus, Manitis Squama) were found to be low cytotoxic to normal mouse lymphoid cells. These findings suggest that the above 3 drugs may be used for effective anticancer drugs in vivo.