Cell Survival Assays for Individualised Chemotherapy in Primary Glioma Cultures—Colourmetric or Luminescent?

Abstract

In vitro chemosensitivity testing of short term primary glioma cultures derived from brain biopsies is still in the research phase and has not yet found a place in clinical use. The main reasons for this slow progression are the small amounts of tissue available and the lack of a suitably sensitive assay capable of use in the clinical setting. This study examines whether the MTS and ATP cell survival assays, which determine cytotoxicity via colorimetric and luminescence analysis respectively, could potentially fulfill this role. Primary glioma cultures were tested for chemosensitivity using the MTS and ATP assays and were found to be generally sensitive to cisplatin and paclitaxel but relatively resistant to carmustine and etoposide. For both assays, LD₅₀ values lay in the range 2 - 130 μg/ml but in the vast majority of cases, those obtained by the ATP assay were markedly lower those obtained by the MTS assay. Moreover, at cell numbers less than 2000 in the cases of paclitaxel and carmustine and less than 4500 in the case of cisplatin, these drugs were generally indicated as ineffective against the glioma cultures tested by the MTS assay but effective against these cultures by the ATP assay. These data clearly demonstrate that the ATP assay is more sensitive when estimating small cell numbers generated by primary glioma cultures from brain biopsies and more reliably detects higher kill rates by anticancer drugs. This study also supports the feasibility of using the ATP assay for chemosensitivity testing in a clinical setting.