Aggregation of lipid rafts activates c-met and c-Src in non-small cell lung cancer cells
Abstract Background Activation of c-Met, a receptor tyrosine kinase, induces radiation therapy resistance in non-small cell lung cancer (NSCLC). The activated residual of c-Met is located in lipid rafts (Duhon et al. Mol Carcinog 49:739-49, 2010). Therefore, we hypothesized that disturbing the integ...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2018-05-01
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| Series: | BMC Cancer |
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| Online Access: | http://link.springer.com/article/10.1186/s12885-018-4501-8 |
| _version_ | 1819053294974140416 |
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| author | Juan Zeng Heying Zhang Yonggang Tan Cheng Sun Yusi Liang Jinyang Yu Huawei Zou |
| author_facet | Juan Zeng Heying Zhang Yonggang Tan Cheng Sun Yusi Liang Jinyang Yu Huawei Zou |
| author_sort | Juan Zeng |
| collection | DOAJ |
| description | Abstract Background Activation of c-Met, a receptor tyrosine kinase, induces radiation therapy resistance in non-small cell lung cancer (NSCLC). The activated residual of c-Met is located in lipid rafts (Duhon et al. Mol Carcinog 49:739-49, 2010). Therefore, we hypothesized that disturbing the integrity of lipid rafts would restrain the activation of the c-Met protein and reverse radiation resistance in NSCLC. In this study, a series of experiments was performed to test this hypothesis. Methods NSCLC A549 and H1993 cells were incubated with methyl-β-cyclodextrin (MβCD), a lipid raft inhibitor, at different concentrations for 1 h before the cells were X-ray irradiated. The following methods were used: clonogenic (colony-forming) survival assays, flow cytometry (for cell cycle and apoptosis analyses), immunofluorescence microscopy (to show the distribution of proteins in lipid rafts), Western blotting, and biochemical lipid raft isolation (purifying lipid rafts to show the distribution of proteins in lipid rafts). Results Our results showed that X-ray irradiation induced the aggregation of lipid rafts in A549 cells, activated c-Met and c-Src, and induced c-Met and c-Src clustering to lipid rafts. More importantly, MβCD suppressed the proliferation of A549 and H1993 cells, and the combination of MβCD and radiation resulted in additive increases in A549 and H1993 cell apoptosis. Destroying the integrity of lipid rafts inhibited the aggregation of c-Met and c-Src to lipid rafts and reduced the expression of phosphorylated c-Met and phosphorylated c-Src in lipid rafts. Conclusions X-ray irradiation induced the aggregation of lipid rafts and the clustering of c-Met and c-Src to lipid rafts through both lipid raft-dependent and lipid raft-independent mechanisms. The lipid raft-dependent activation of c-Met and its downstream pathways played an important role in the development of radiation resistance in NSCLC cells mediated by c-Met. Further studies are still required to explore the molecular mechanisms of the activation of c-Met and c-Src in lipid rafts induced by radiation. |
| first_indexed | 2024-12-21T12:33:27Z |
| format | Article |
| id | doaj.art-5ad464e168704b80988e3dd2705aa816 |
| institution | Directory Open Access Journal |
| issn | 1471-2407 |
| language | English |
| last_indexed | 2024-12-21T12:33:27Z |
| publishDate | 2018-05-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Cancer |
| spelling | doaj.art-5ad464e168704b80988e3dd2705aa8162022-12-21T19:03:58ZengBMCBMC Cancer1471-24072018-05-0118111110.1186/s12885-018-4501-8Aggregation of lipid rafts activates c-met and c-Src in non-small cell lung cancer cellsJuan Zeng0Heying Zhang1Yonggang Tan2Cheng Sun3Yusi Liang4Jinyang Yu5Huawei Zou6The First Oncology Department, Shengjing Hospital affiliated with China Medical UniversityThe First Oncology Department, Shengjing Hospital affiliated with China Medical UniversityThe First Oncology Department, Shengjing Hospital affiliated with China Medical UniversityThe First Oncology Department, Shengjing Hospital affiliated with China Medical UniversityThe First Oncology Department, Shengjing Hospital affiliated with China Medical UniversityThe First Oncology Department, Shengjing Hospital affiliated with China Medical UniversityThe First Oncology Department, Shengjing Hospital affiliated with China Medical UniversityAbstract Background Activation of c-Met, a receptor tyrosine kinase, induces radiation therapy resistance in non-small cell lung cancer (NSCLC). The activated residual of c-Met is located in lipid rafts (Duhon et al. Mol Carcinog 49:739-49, 2010). Therefore, we hypothesized that disturbing the integrity of lipid rafts would restrain the activation of the c-Met protein and reverse radiation resistance in NSCLC. In this study, a series of experiments was performed to test this hypothesis. Methods NSCLC A549 and H1993 cells were incubated with methyl-β-cyclodextrin (MβCD), a lipid raft inhibitor, at different concentrations for 1 h before the cells were X-ray irradiated. The following methods were used: clonogenic (colony-forming) survival assays, flow cytometry (for cell cycle and apoptosis analyses), immunofluorescence microscopy (to show the distribution of proteins in lipid rafts), Western blotting, and biochemical lipid raft isolation (purifying lipid rafts to show the distribution of proteins in lipid rafts). Results Our results showed that X-ray irradiation induced the aggregation of lipid rafts in A549 cells, activated c-Met and c-Src, and induced c-Met and c-Src clustering to lipid rafts. More importantly, MβCD suppressed the proliferation of A549 and H1993 cells, and the combination of MβCD and radiation resulted in additive increases in A549 and H1993 cell apoptosis. Destroying the integrity of lipid rafts inhibited the aggregation of c-Met and c-Src to lipid rafts and reduced the expression of phosphorylated c-Met and phosphorylated c-Src in lipid rafts. Conclusions X-ray irradiation induced the aggregation of lipid rafts and the clustering of c-Met and c-Src to lipid rafts through both lipid raft-dependent and lipid raft-independent mechanisms. The lipid raft-dependent activation of c-Met and its downstream pathways played an important role in the development of radiation resistance in NSCLC cells mediated by c-Met. Further studies are still required to explore the molecular mechanisms of the activation of c-Met and c-Src in lipid rafts induced by radiation.http://link.springer.com/article/10.1186/s12885-018-4501-8Lipid raftsMesenchymal-epithelial transition factor (c-met)C-SrcRadiation resistanceNSCLC |
| spellingShingle | Juan Zeng Heying Zhang Yonggang Tan Cheng Sun Yusi Liang Jinyang Yu Huawei Zou Aggregation of lipid rafts activates c-met and c-Src in non-small cell lung cancer cells BMC Cancer Lipid rafts Mesenchymal-epithelial transition factor (c-met) C-Src Radiation resistance NSCLC |
| title | Aggregation of lipid rafts activates c-met and c-Src in non-small cell lung cancer cells |
| title_full | Aggregation of lipid rafts activates c-met and c-Src in non-small cell lung cancer cells |
| title_fullStr | Aggregation of lipid rafts activates c-met and c-Src in non-small cell lung cancer cells |
| title_full_unstemmed | Aggregation of lipid rafts activates c-met and c-Src in non-small cell lung cancer cells |
| title_short | Aggregation of lipid rafts activates c-met and c-Src in non-small cell lung cancer cells |
| title_sort | aggregation of lipid rafts activates c met and c src in non small cell lung cancer cells |
| topic | Lipid rafts Mesenchymal-epithelial transition factor (c-met) C-Src Radiation resistance NSCLC |
| url | http://link.springer.com/article/10.1186/s12885-018-4501-8 |
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