Back to Search
Start Over
High levels of EGFR prevent sulforaphane-induced reactive oxygen species-mediated apoptosis in non-small-cell lung cancer cells.
- Source :
-
Phytomedicine : international journal of phytotherapy and phytopharmacology [Phytomedicine] 2019 Nov; Vol. 64, pp. 152926. Date of Electronic Publication: 2019 Apr 13. - Publication Year :
- 2019
-
Abstract
- Background: Sulforaphane (SFN) has been shown to induce the production of reactive oxygen species (ROS) and inhibit epidermal growth factor receptor (EGFR)-mediated signaling in non-small-cell lung cancer (NSCLC). NSCLC cells harboring constitutively active EGFR mutations are more sensitive to SFN treatment than cells with wild-type EGFR, but whether NSCLC cells with high levels of EGFR expression are more resistant or sensitive to SFN treatment is not known.<br />Study Design: We employed a pair of cell lines, CL1-0 and CL1-5, which have the same genetic background but different levels of EGFR expression, to examine the effects of high EGFR level in the sensitivity to SFN.<br />Methods: The effect of SFN on cell viability and tumorigenicity was examined by trypan blue dye-exclusion assay, clonogenic assays, flow cytometry, and immunoblotting in vitro as well as tumorigenicity study in vivo. ROS levels in cells were assessed by flow cytometry using the ROS-reactive fluorescent indicator CM-H2DCFDA. Knockdown of EGFR in CL1-5 cells was infected with an EGFR-targeting small hairpin (interfering) RNA (shRNA)-containing lentivirus.<br />Results: We present evidence that cells with high-level EGFR expression (CL1-5) are more resistant to SFN treatment than those with low-level expression (CL1-0). SFN treatment produced a similar increase in ROS and caused arrest of a cell population at S-phase accompanied by the induction of γH2AX, a DNA damage-response marker, in both cell sublines. However, SFN induced apoptosis only in the high-EGFR-expressing CL1-0 subline. Pretreatment with the antioxidant N-acetyl-L-cysteine prevented SFN-induced apoptosis in CL1-0 cells and production of γH2AX in both CL1-0 and CL1-5 cells. shRNA-mediated knockdown of EGFR in CL1-5 cells rendered the cells susceptible to SFN-induced apoptosis.<br />Conclusion: The cellular effects produced by SFN in NSCLC cells are largely mediated by SFN-induced production of ROS. Cells with higher levels of EGFR were more resistant to SFN treatment and showed resistance to SFN-induced apoptosis, suggesting that high EGFR levels protect cells from SFN-induced apoptosis. Despite this, we found that SFN retained the ability to inhibit the growth of NSCLC tumors with high-level EGFR expression in vivo.<br /> (Copyright © 2019 Elsevier GmbH. All rights reserved.)
- Subjects :
- Animals
Antioxidants pharmacology
Carcinogenesis drug effects
Cell Line, Tumor
Cell Survival drug effects
DNA Damage
Drug Resistance, Neoplasm
ErbB Receptors genetics
ErbB Receptors metabolism
Humans
Male
Mice
Mice, Inbred BALB C
Mutation
Signal Transduction drug effects
Sulfoxides
Xenograft Model Antitumor Assays
Anticarcinogenic Agents pharmacology
Apoptosis drug effects
Carcinoma, Non-Small-Cell Lung drug therapy
Isothiocyanates pharmacology
Lung Neoplasms drug therapy
Reactive Oxygen Species metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1618-095X
- Volume :
- 64
- Database :
- MEDLINE
- Journal :
- Phytomedicine : international journal of phytotherapy and phytopharmacology
- Publication Type :
- Academic Journal
- Accession number :
- 31454652
- Full Text :
- https://doi.org/10.1016/j.phymed.2019.152926