Separating Response of Tumor and non-Tumor Cells to Drug In Vitro by Quantifying a Mutation

Conventional in vitro assays measure the effect of drugs on total cells, while separating the effect to those on tumor and non-tumor cells is important for assessing drug specificity. Our aim was to evaluate the feasibility of separating the efficacy of vemurafenib on tumor and non-tumor cells in a mixed culture.

Melanoma A2058 cells and CCD18Co non-tumor cells were mixed and treated with vemurafenib. DNA was subjected to digital PCR to determine the ratio of the mutant 1799A to the wild-type 1799T alleles and viabilities of total cells were subsequently calculated as percentages of tumor and non-tumor cells.

The set-up proportion of tumor cells correlated well with the calculated one. The calculated viability of tumor cells decreased with increasing doses of vemurafenib while that of the non-tumor cells remained rather constant. Variability of digital PCR data was high.

Using the BRAF mutation 1799T>A to separate the response of tumor and non-tumor cells to a drug, such as vemurafenib, is feasible, supporting a foundation for a genetic in vitro tool for testing drug efficacy and specificity.