title: [Effect of autophagy inhibitor combined with EGFR inhibitor on triple-negative breast cancer MDA-MB-468 and MDA-MB-231 cells].
abstract: OBJECTIVE
  To investigate the effect of combined administration of autophagy inhibitor 3-methyladenine/bafilomycin A1 and EGFR inhibitor gefitinib on triple-negative breast cancer MDA-MB-468, MDA-MB-231 cells and estrogen receptor-positive MCF-7 cells.
  
  
  METHODS
  All the cells were treated with 3-methyladenine/bafilomycin A1 and/or gefitinib. The effect of autophagy inhibitor and gefitinib on the cell growth was evaluated by MTT assay. Cell apoptosis was detected by flow cytometry. Western blot analysis was used to determine the alteration of autophagy-related protein (such as LC3) and apoptosis-related proteins (such as caspase-3 and caspase-9).
  
  
  RESULTS
  MTT assay showed that the IC50 in the GE+ 3-MA and GE+ BAF groups were (4.1±0.2) μmol/L and (3.8±0.3) μmol/L, significantly lower than that of the gefitinib alone group [(7.0±0.2) μmol/L] in MDA-MB-468 cells (P<0.05). Similarly, the IC50 in the GE+ 3-MA and GE+ BAF groups were (9.7±0.1) μmol/L and (7.7±0.2) μmol/L, significantly lower than that of the gefitinib alone group [(14.7±0.1) μmol/L]in MDA-MB231 cells (P<0.05). The flow cytometry assay revealed that the apoptosis rates of MDA-MB-468 cells in GE, GE+ 3-MA and GE+ BAF groups were (12.43±3.18)%, (23.37±2.71)% and (18.71±2.81)%, respectively. The apoptosis rates of MDA-MB-231 cells of the GE, GE+ 3-MA and GE+ BAF groups were (12.15±1.82)%, (16.94±2.19)% and (33.83±5.92) %, significantly higher than that of the gefitinib alone group (All P<0.05). The apoptosis rates of the MCF-7 cells were not changed significantly among the three groups (P>0.05). Western blot data showed that the expression levels of LC3 and p-Akt were decreased in the combined groups than that of the gefitinib alone group, while the p-PTEN, caspase-3 and caspase-9 were increased.
  
  
  CONCLUSIONS
  Autophagy inhibitor may enhance the sensitivity to gefitinib in MDA-MB-468 and MDA-MB-231 cells by activation of the PTEN/P13K/Akt pathway. Apoptosis in MDA-MB-468 and MDA-MB-231 cells might be enhanced by the combination treatment through caspase cascade.
authors.affiliation: School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Jinan 250022, China.
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Liu
authors.affiliation: School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Jinan 250022, China.
authors.forename: K W
authors.initials: KW
authors.lastname: He
authors.affiliation: Basic Laboratory, Shandong Cancer Hospital Affiliated to Shandong UniversityShandong Academy of Medical Sciences, Jinan 250117, China.
authors.forename: X G
authors.initials: XG
authors.lastname: Song
authors.affiliation: Department of Breast Surgery, Shandong Cancer Hospital Affiliated to Shandong University Shandong Academy of Medical Sciences, Jinan 250117, China.
authors.forename: X Z
authors.initials: XZ
authors.lastname: Wang
authors.affiliation: Department of Internal Medicine, Shandong Cancer Hospital Affiliated to Shandong University Shandong Academy of Medical Sciences, Jinan 250117, China.
authors.forename: P Y
authors.initials: PY
authors.lastname: Zhuo
authors.affiliation: Basic Laboratory, Shandong Cancer Hospital Affiliated to Shandong UniversityShandong Academy of Medical Sciences, Jinan 250117, China.
authors.forename: X W
authors.initials: XW
authors.lastname: Wang
authors.affiliation: Department of Breast Surgery, Shandong Cancer Hospital Affiliated to Shandong University Shandong Academy of Medical Sciences, Jinan 250117, China.
authors.forename: Q H
authors.initials: QH
authors.lastname: Ma
authors.affiliation: Department of Breast Surgery, Shandong Cancer Hospital Affiliated to Shandong University Shandong Academy of Medical Sciences, Jinan 250117, China.
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Huo
authors.affiliation: Department of Breast Surgery, Shandong Cancer Hospital Affiliated to Shandong University Shandong Academy of Medical Sciences, Jinan 250117, China.
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Yu
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001343:Autophagy; D000071183:Autophagy-Related Proteins / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D000077156:Gefitinib; D006801:Humans; D061986:MCF-7 Cells; D018942:Macrolides / Q000494:pharmacology*; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011799:Quinazolines / Q000494:pharmacology*; D064726:Triple Negative Breast Neoplasms / Q000473:pathology*
chemical_list: D000970:Antineoplastic Agents; D000071183:Autophagy-Related Proteins; C477012:MAP1LC3A protein, human; D018942:Macrolides; D008869:Microtubule-Associated Proteins; D011799:Quinazolines; C025946:3-methyladenine; C040929:bafilomycin A1; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053453:Caspase 9; D000225:Adenine; D000077156:Gefitinib