Synthetic, Structural, and Anticancer Activity Evaluation Studies on Novel Pyrazolylnucleosides

Yadav, Yogesh; Sharma, Deepti; Kaushik, Kumar; Kumar, Vineet; Jha, Amitabh; Prasad, Ashok K.; Len, Christophe; Malhotra, Sanjay V.; Wengel, Jesper; Parmar, Virinder S.

Details of the methodology are described at http://dtp.nci.nih.gov/branches/btb/ivclsp.html. Briefly, the panel was organized into nine subpanels representing a diverse histology: leukemia, melanoma, and cancers of the lung, colon, kidney, ovary, breast, prostate, and central nervous system. The cells were grown in supplemented RPM1 1640 medium for 24 h. For the five dose study, the test compounds were dissolved in DMSO and incubated with cells at five concentrations with 10-fold dilutions, the highest being 10 −4 M and the others being 10 −5 , 10 −6 , 10 −7 , and 10 −8 M. The assay was terminated by the addition of cold trichloroacetic acid, and the cells were fixed and stained with sulforhodamine B. The bound stain was solubilized, and the absorbance was read on an automated plate reader. The cytostatic parameter, which determines the 50% growth inhibition (GI 50 ) of the tumor cells, was calculated from time zero, control growth, and the absorbance at the five concentration levels. The cytotoxic parameter, lethal concentration (LC 50 is the concentration of a drug resulting in a 50% reduction in the measured protein at the end of the drug treatment when compared to that at the beginning), indicating a net loss of cells following the treatment, was calculated as the average of two independent experiments.