Comparative study of the radiosensitizing and cell cycle effects of vinflunine and vinorelbine, in vitro.

Background: Vinca alkaloids are an important class of anticancer agents and semisynthetic vinca alkaloids are developed to improve the therapeutic index of this class of drugs. In the present study, a direct comparison was made between vinflunine and vinorelbine regarding their radiosensitizing and cell cycle effects.

Methods: Four human tumour cell lines were tested under identical experimental conditions, using equitoxic concentrations of vinflunine and vinorelbine.

The relation between deoxycytidine kinase activity and the radiosensitising effect of gemcitabine in eight different human tumour cell lines.

Background: Gemcitabine (dFdC) is an active antitumour agent with radiosensitising properties, shown both in preclinical and clinical studies. In the present study, the relation between deoxycytidine kinase (dCK) activity and the radiosensitising effect of gemcitabine was investigated in eight different human tumour cell lines.

Methods: Tumour cells were treated with dFdC (0-100 nM) for 24 h prior to radiotherapy (RT) (gamma-Co60, 0-6 Gy, room temperature).

The radiosensitising effect of difluorodeoxyuridine, a metabolite of gemcitabine, in vitro.

Purpose: Gemcitabine is an active antitumour agent with radiosensitising properties. Gemcitabine is rapidly metabolised, intracellularly as well as extracellularly, by deoxycytidine deaminase to difluorodeoxyuridine (dFdU), a compound with little antitumour activity. However, plasma concentrations are maintained for a prolonged period (>24 h) at levels known to cause growth inhibition.

Cell cycle effects of vinflunine, the most recent promising Vinca alkaloid, and its interaction with radiation, in vitro.

Purpose: Vinflunine (VFL) is a novel third generation Vinca alkaloid with superior antitumour activity in preclinical models and an anticipated more favourable toxicity profile compared to the other Vinca alkaloids.

Method: We investigate the radiosensitising properties of VFL and its cell cycle effects in four human tumour cell lines (ECV304, MCF-7, H292, and CAL-27). The sulforhodamine B test was used to determine cell survival, and cell cycle analysis was performed by flow cytometry.

Unraveling the mechanism of radiosensitization by gemcitabine: the role of TP53.

Gemcitabine has excellent radiosensitizing properties, as shown in both preclinical and clinical studies. Radiosensitization correlated with the early S-phase block of gemcitabine. In the present study, we investigated the role of TP53 in the radiosensitizing effect of gemcitabine.

Cell cycle effect of gemcitabine and its role in the radiosensitizing mechanism in vitro.

Purpose: The mechanism of radiosensitization by gemcitabine is still unclear. It has been hypothesized that the accumulation of cells in early S phase may play a role in enhancing radiosensitivity.

Methods And Materials: The schedule dependency of the radiosensitizing effect was studied in ECV304, human bladder cancer cells, and H292, human lung cancer cells, by varying the incubation time and time interval between gemcitabine and radiation treatment.

Comparison of the sulforhodamine B assay and the clonogenic assay for in vitro chemoradiation studies.

Purpose: Since there is a growing interest in preclinical research on interactions between radiation and cytotoxic agents, this study focused on the development of an alternative to the very laborious clonogenic assay (CA).

Methods: The colorimetric sulforhodamine B (SRB) assay was compared to the clonogenic assay for radiosensitivity testing in two lung cancer cell lines (A549, H292), one colon cancer cell line (HT-29) and one breast cancer cell line (MCF-7). In addition, the combination of the radiosensitizing agent gemcitabine and radiation was investigated with both assays.