Objective: To determine the inhibitory effect of norcantharidin (NCTD) on the half maximal inhibitory concentration (IC50) of 72 cell lines of 12 major human cancers

in order to provide an index for growth inhibition effect. Method: The inhibitory effect of norcantharidin (NTCD) was determined by measuring and observing the half maximal inhibitory concentration (IC50) for individual cell lines using an IncuCyteTM ZOOM-based proliferation assay. Briefly

cells of individual lines at defined densities were treated with norcantharidin at various concentration

and their relative growth rates were assessed by measuring the relative cell densities once every 3 hours for 72 hours. In addition

digital images were captured at each time point and recorded. Result: The IC50 of NCTD for the 72 cancer cell lines varied considerably

ranging from 2 to 66 μmol·L-1

with an overall median value of (24.63±12.97) μmol·L-1. Among the 12 cancer cell lines

the mean IC50 of NCTD for two liver cancers (hepatocellular carcinoma cholangiocarcinoma)

gastric cancer

prostate cancer

leukemia

central nervous system cancer

renal cancer were lower than the overall mean value. Also

significant differences among various cancer types and individuals with the same cancer were evident. Conclusion: There are remarkable differences in sensitivity towards NCTD among various cancer types and individuals with the same cancer

indicating the individualized sensitive nature of NTCD and the great future prospect for the development of individualized therapies with NTCD. Many cancers show a similar mean IC50 of NCTD with hepatocellular carcinoma and gastric cancers

for which NTCD is effective clinically

suggesting that NTCD could also be effective for all of these cancers.