title: Crude phenolic extracts from extra virgin olive oil circumvent de novo breast cancer resistance to HER1/HER2-targeting drugs by inducing GADD45-sensed cellular stress, G2/M arrest and hyperacetylation of Histone H3.
abstract: Characterization of the molecular function of complex phenols naturally present in extra virgin olive oil (EVOO) against the HER2-gene amplified JIMT-1 cell line, a unique breast cancer model that inherently exhibits cross-resistance to multiple HER1/2-targeted drugs including trastuzumab, gefitinib, erlotinib and lapatinib, may underscore innovative cancer molecules with novel therapeutic targets because they should efficiently circumvent de novo resistance to HER1/2 inhibitors in order to elicit tumoricidal effects. We identified pivotal signaling pathways associated with the efficacy of crude phenolic extracts (PEs) obtained from 14 monovarietals of Spanish EVOOs. i) MTT-based cell viability and HPLC coupled to time-of-flight (TOF) mass spectrometry assays revealed that anti-cancer activity of EVOO PEs positively correlated with the phenolic index (i.e., total content of phenolics) and with a higher presence of the complex polyphenols secoiridoids instead of lignans. ii) Genome-wide analyses using 44 K Agilent's whole human arrays followed by Gene Set Enrichment Analysis (GSEA)-based screening of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database revealed a differential modulation of the JIMT-1 transcriptome at the level of the cell cycle and p53 pathways. EVOO PEs differentially impacted the expression status of stress-sensing, G2-M check-point-related GADD45 genes and of p53-related CDKN1A, CDKN1C and PMAIP-1 genes. iii) Cell cycle and fluorescence microscopy analyses confirmed that secoiridoid-rich EVOO PE inhibited mitosis to promote G2-M cell cycle arrest. This was accompanied with the appearance of diffuse, even DNA staining with γH2AX and pan-nuclear hyperacetylation of Histone H3 at Lysine 18. iv) Semi-quantitative Signaling Node Multi-Target ELISAs determined that secoiridoid-rich EVOO PE drastically activated the mitogen-activated protein kinases MEK1 and p38 MAPK, a GADD45-related kinase involved in Histone H3 acetylation. Secoiridoids, a family of complex polyphenols characteristic of Oleaceae plants, appear to permit histones to remain in hyperacetylated states and through the resulting alterations in gene regulation to reduce mitotic viability and metabolic competence of breast cancer cells inherently refractory to HER-targeting therapies ab initio. Oleaceae secoiridoids could provide a valuable phytochemical platform for the design of more pharmacologically active second-generation phytopharmaceutical anti-breast cancer molecules with a unique mode of action.
authors: Catalan Institute of Oncology, 2Girona Biomedical Research Institute, Girona, Catalonia, Spain.
authors: Cristina
authors: C
authors: Oliveras-Ferraros
authors: Salvador
authors: S
authors: Fernández-Arroyo
authors: Alejandro
authors: A
authors: Vazquez-Martin
authors: Jesús
authors: J
authors: Lozano-Sánchez
authors: Sílvia
authors: S
authors: Cufí
authors: Jorge
authors: J
authors: Joven
authors: Vicente
authors: V
authors: Micol
authors: Alberto
authors: A
authors: Fernández-Gutiérrez
authors: Antonio
authors: A
authors: Segura-Carretero
authors: Javier A
authors: JA
authors: Menendez
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms; D002453:Cell Cycle / Q000187:drug effects*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D066246:ErbB Receptors; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006657:Histones / Q000378:metabolism*; D006801:Humans; D048369:MAP Kinase Kinase 1 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D000069463:Olive Oil; D010636:Phenols / Q000494:pharmacology; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013312:Stress, Physiological / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D000097642:GADD45 Proteins
chemical_list: D000970:Antineoplastic Agents; D018797:Cell Cycle Proteins; D066246:ErbB Receptors; D006657:Histones; D048369:MAP Kinase Kinase 1; D016328:NF-kappa B; D009687:Nuclear Proteins; D000069463:Olive Oil; D010636:Phenols; D010936:Plant Extracts; D010938:Plant Oils; D051057:Proto-Oncogene Proteins c-akt; D018719:Erb-b2 Receptor Tyrosine Kinases; D050796:STAT3 Transcription Factor; D048051:p38 Mitogen-Activated Protein Kinases; C439070:GADD45A protein, human; D000097642:GADD45 Proteins; C512478:EGFR protein, human; C508053:ERBB2 protein, human