## Background and objective: Photodynamic therapy (pdt) is the combination of a photosensitizer with laser light to induce preferential destruction of malignant cells. in this study two new photosensitizers--5,10,15,20-meta-tetra(hydroxyphenyl) chlorin (m-thpc) and m-thpc methoxypeg2000 derivative
The effect of hypoxia on acquired drug resistance and response to epidermal growth factor in chinese hamster lung fibroblasts and human breast-cancer cells in vitro
✍ Scribed by R. Kalra; A-M. Jones; J. Kirk; G. E. Adams; I. J. Stratford
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- French
- Weight
- 646 KB
- Volume
- 54
- Category
- Article
- ISSN
- 0020-7136
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Prolonged hypoxia induced transient drug resistance in Chinese hamster lung fibroblasts. Previously hypoxic cells were resistant to adriamycin and resistant to etoposide. Complete recovery of etoposide sensitivity was observed following re‐aeration for 24 hr. A change in P‐glycoprotein expression was unlikely to contribute to the resistance caused by hypoxia, since adriamycin resistance was not reversed by verapamil. However, alteration in the plasma membrane structure may be involved, since previously hypoxic cells were resistant to extracellular superoxide radical generated by the addition of xanthine/ xanthine oxidase. In contrast, adriamycin sensitivity was not altered by hypoxia in 3 human breast‐cancer cell lines. MDA‐468 and MCF‐7/Adr differed in their response to EGF, independent of the presence of hypoxia. These results suggest that hypoxic‐stress‐induced drug resistance is not generalized.
📜 SIMILAR VOLUMES
## Abstract ## BACKGROUND. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR‐TKIs) have demonstrated clinical benefit in patients with nonsmall cell lung cancer (NSCLC), particularly those with tumors that have EGFR‐TK domain mutations. Moreover, the EGFR and cyclooxygenase (COX)‐2