Interaction of paclitaxel (Taxol) and irradiation. In-vitro differences between tumor and fibroblastic cells

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • N Cordes - , University Hospital at the Friedrich-Alexander University Erlangen-Nürnberg (Author)
  • L Plasswilm - (Author)
  • R Sauer - (Author)

Abstract

AIM: Optimal dose and schedule of paclitaxel in combined drug-irradiation treatment could not be determined for most of tumors yet. The aim of this study was to compare in vitro cytotoxicity and radiosensitizing abilities as a function of single paclitaxel (Taxol) exposure in tumor and fibroblastic cells using different drug incubation irradiation intervals.

MATERIAL AND METHOD: A lung-carcinoma (SK-LU-1), glioblastoma (U-138 MG) and rodent fibroblast cell line (HyB14FAF28) were used. The clonogenic assay was applied for survival investigation. alpha beta-values were calculated using the linear-quadratic model (log S = -alpha D - beta D2). Cytotoxicity of Taxol was examined at 0 to 50 microM. Combined Taxol-radiotherapy exposure was accomplished with 10 microM Taxol plus 10 Gy irradiation (RT) following after a 1-hour and 9-hour interval. For controls cells were exposed to Cremophor EL/ethanol (CEL/eth) and a phosphate buffered saline (PBS).

RESULTS: Single Taxol exposure (10 microM) resulted in 0.54/0.50/0.84 (3-hours incubation) and 0.094/0.48/0.82 (15-hours incubation) survival of SK-LU-1, U-138 MG and HyB14FAF28 cells, respectively. Taxol concentrations from 2 to 50 microM only had cytotoxic effect in tumor cells. Single dose RT (10 Gy) led to cell survival of 0.0006/0.006/0.03. The diluent CEL/eth also showed cytotoxic activity. Taxol plus RT led to cell survival of 0.00025/0.0014/0.042 (1 hour) and 0.0004/0.0019/0.04 (9 hours) without significant difference between chosen time intervals. alpha beta-values showed great variation lacking evidence for definite radiosensitization. alpha increase after Taxol and alpha decrease after CEL/eth exposure were detected.

CONCLUSIONS: The data presented demonstrate a potential beneficial effect, described as co-operation, by combining Taxol and RT in human tumor cells and rodent fibroblasts. High intrinsic alpha components of the tumor cells as well as CEL/eth's antagonizing actions could be likely to disturb and influence paclitaxel's abilities leading to radiosensitization.

Details

Original languageEnglish
Pages (from-to)175-81
Number of pages7
JournalStrahlentherapie und Onkologie
Volume175
Issue number4
Publication statusPublished - Apr 1999
Peer-reviewedYes
Externally publishedYes

External IDs

Scopus 0032904227
ORCID /0000-0001-5684-629X/work/147674894

Keywords

Keywords

  • Adenocarcinoma, Animals, Antineoplastic Agents, Phytogenic/administration & dosage, Cell Survival/drug effects, Cells, Cultured, Dose-Response Relationship, Drug, Dose-Response Relationship, Radiation, Fibroblasts/drug effects, Flow Cytometry, Glioblastoma, Humans, Lung Neoplasms, Paclitaxel/administration & dosage, Particle Accelerators, Radiation-Sensitizing Agents/administration & dosage, Radiotherapy, High-Energy/statistics & numerical data, Rodentia, Time Factors, Tumor Cells, Cultured/drug effects