Radiosensitivity of Mesothelioma Cell Lines

Abstract

The present study was carried out in order to examine the radiosensitivity of malignant pleural mesothelioma cell lines. Cell kinetics, radiation-induced delay of the cell cycle and DNA ploidy of the cell lines were also determined. For comparison an HeLa and a human foetal fibroblast cell line were simultaneously explored. Six previously cytogenetically and histologically characterized mesothelioma tumor cell lines were applied. A rapid tiazolyl blue microtiter (MTT) assay was used to analyze radiosensitivity and cell kinetics and DNA ploidy of the cultured cells were determined by flow cytometry. The survival fraction after a dose of 2 Gy (SF2), parameters alpha and beta of the linear quadratic model (LQ-model) and mean inactivation dose (D(MID)) were also estimated. The DNA index of four cell lines equaled 1.0 and two cell lines equaled 1.5 and 1.6. Different mesothelioma cell lines showed a great variation in radiosensitivity. Mean survival fraction after a radiation dose of 2 Gy (SF2) was 0.60 and ranged from 0.36 to 0.81 and mean alpha value was 0.26 (range 0.48 - 0.083). The SF2 of the most sensitive diploid mesothelioma cell line was 0.36: less than that of the foetal fibroblast cell line (0.49). The survival fractions (0.81 and 0.74) of the two most resistant cell lines, which also were aneuploid, were equal to that of the HeLa cell line (0.78). The alpha/beta ratios of the most sensitive cell lines were almost an order of magnitude greater than those of the two most resistant cell lines. Radiation-induced delay of the most resistant aneuploid cell line was similar to that of HeLa cells but in the most sensitive (diploid cells) there was practically no entry into the G1 phase following the 2 Gy radiation dose during 36 h.

Malignant pleural mesothelioma

“…Although radiation therapy has shown efficacy on mesothelioma cell lines [77], it has proven disappointing in mesothelioma patients and poor results have been described in several series [78,79]. One of the major problems in performing radiation therapy is determining the volume of the target area, which includes the diaphragm, mediastinum, and chest wall and excludes the lung.…”

Heterogeneity of in vitro radiosensitivity in human bladder cancer cells

“…We have there-fore used two endpoints to evaluate radiation sensitivity: the clonogenic survival assay and the MTT assay, both of which have been used successfully for assessment of radiosensitivity for in vitro cell lines [37][38][39][40]. The radiobiological parameters examined were the surviving fraction of cells treated with 2 Gy radiation (SF 2 ), the surviving fraction of cells treated with 8 Gy radiation (SF 8 ), and the values for ␣ and ␤, estimated from the linearquadratic model.…”

Altered Fractionation of Hemithorax Irradiation for Pleural Mesothelioma and Failure Patterns After Treatment

“…Differences in radiosensitivity were best distinguished by comparison of SF 2 values. Hakkinen et al (31) found significant differences in radiosensitivity between mesothelioma cell lines from different patients as expressed by the survival fractions at SF 2 or by the initial shape of the survival curve, a. In three mesothelioma cell lines derived from our patients the .…”