Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) frequently occurs in many human cancers and hampers their therapeutic use. A large body of evidence has demonstrated the pro-survival role of autophagy in many human cancers. However, whether autophagy is involved in the induction of erlotinib resistance in tongue squamous cell carcinoma (TSCC) remains unknown. In this report, we found that autophagy prior to or induced by erlotinib treatment plays an important role in erlotinib resistance in tongue cancer cells. Using LC3 transfection, we observed that autophagy is upregulated and further induced when treated with erlotinib. Moreover, we found that autophagy plays a cytoprotective role by MTT analysis of the cell viability in TSCCs when treated with rapamycin or hydroxychloroquine (HCQ) in combination with erlotinib. However, 3-methyladenine (3-MA) did not influence the autophagy. Then, through siRNA technology and WB, we found that erlotinib-induced autophagy is mediated by ATG5 but not Beclin1. Also, knockdown of ATG5 significantly decreased the erlotinib resistance and knockdown of Beclin1 did not affect the sensitivity to erlotinib in TSCCs. Taken together, this indicates the critical role of non-canonical autophagy in erlotinib resistance in TSCCs.
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http://dx.doi.org/10.1007/s13277-015-4689-z | DOI Listing |
Anticancer Drugs
August 2024
Department of Thoracic Surgery, Peking University Cancer Hospital Inner Mongolia Hospital.
This study aims to demonstrate the effect of toadflax (bufalin) on erlotinib resistance in nonsmall cell lung cancer (NSCLC) by inhibiting the fibroblast growth factor receptor (FGFR). The microfluidic mobility transferase and caliper mobility-shift assays were employed to detect the FGFR inhibition by bufalin and the binding reversibility. Further, the inhibitory effects of bufalin were determined in HCC827 and HCC827/ER cells in vitro, investigating relative FGFR overexpression by quantitative reverse transcriptase-PCR (RT-qPCR) and FGFR downstream proteins, that is, FGFR substrate 2 (FRS2), extracellular signal-regulated kinase (ERK), and S6 by western blot analysis.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
Computational Genomics Division, National Institute of Genomic Medicine, Mexico City 14610, Mexico.
HER2-positive (HER2+) breast cancer is characterized by the overexpression of the ERBB2 (HER2) gene, which promotes aggressive tumor growth and poor prognosis. Targeting the ERBB2 pathway with single-agent therapies has shown limited efficacy due to resistance mechanisms and the complexity of gene interactions within the tumor microenvironment. This study aims to explore potential drug synergies by analyzing gene-drug interactions and combination therapies that target the ERBB2 pathway in HER2+ breast tumors.
View Article and Find Full Text PDFDrug Dev Res
December 2024
Chemistry Department, Faculty of Science (Boys), Nasr City, Al-Azhar University, Cairo, Egypt.
The design and synthesis of unique two series of fluorinated sulfonamides 3a-f and 5a-g utilizing nucleophilic aromatic substitution reactions of tetrafluorophthalonitrile 1 with various sulfonamides 2 under a variety of different reactions conditions were the key goals of the current research. The chemical composition of the generated products has been investigated via mass spectroscopy, HNMR, CNMR, infrared, and elemental analyzes. Antimicrobial studies were conducted in vitro to evaluate the activity of all new synthesized compounds against resistant strains.
View Article and Find Full Text PDFThorac Cancer
December 2024
Department of Chemotherapy, Japanese Red Cross Medical Center, Shibuya, Tokyo, Japan.
Introduction: First-line osimertinib is widely used to treat patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancers (NSCLC). In clinical practice, rechallenge therapy with another EGFR-tyrosine kinase inhibitor (TKI) is often performed after first-line TKI discontinuation owing to resistance or toxicity; however, the efficacy and toxicity of EGFR-TKI rechallenge after first-line osimertinib have not been adequately investigated. This study aimed to examine the efficacy and safety of EGFR-TKI rechallenge with another TKI.
View Article and Find Full Text PDFCell Commun Signal
December 2024
International Research Centre for Food and Health, College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China.
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