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Clinical response to chemotherapy in oesophageal adenocarcinoma patients is linked to defects in mitochondria.
J. Pathol. 230, 410-419 (2013)
Chemotherapeutic drugs kill cancer cells, but it is unclear why this happens in responding patients but not in non-responders. Proteomic profiles of patients with oesophageal adenocarcinoma may be helpful in predicting response and selecting more effective treatment strategies. In this study, pre-therapeutic oesophageal adenocarcinoma biopsies were analysed for proteomic changes associated with response to chemotherapy by MALDI imaging mass spectrometry. Resulting candidate proteins were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and investigated for functional relevance in vitro. Clinical impact was validated in pretherapeutic biopsies from an independent patient cohort. Studies on the incidence of these defects in other solid tumours were included. We discovered that clinical response to cisplatin correlated with pre-existing defects in the mitochondrial respiratory chain complexes of cancer cells, caused by loss of specific cytochrome c oxidase (COX) subunits. Knockdown of a COX protein altered chemosensitivity in vitro, increasing the propensity of cancer cells to undergo cell death following cisplatin treatment. In an independent validation, patients with reduced COX protein expression prior to treatment exhibited favourable clinical outcomes to chemotherapy, whereas tumours with unchanged COX expression were chemoresistant. In conclusion, previously undiscovered pre-existing defects in mitochondrial respiratory complexes cause cancer cells to become chemosensitive: mitochondrial defects lower the cells' threshold for undergoing cell death in response to cisplatin. By contrast, cancer cells with intact mitochondrial respiratory complexes are chemoresistant and have a high threshold for cisplatin-induced cell death. This connection between mitochondrial respiration and chemosensitivity is relevant to anticancer therapeutics that target the mitochondrial electron transport chain.
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Publication type
Article: Journal article
Document type
Scientific Article
Keywords
Cox7a2 ; Maldi Imaging Mass Spectrometry ; Chemotherapy ; Oesophageal Adenocarcinoma ; Tumour Response; Cytochrome-c-oxidase ; Imaging Mass-spectrometry ; Alpha-tocopheryl Succinate ; Vitamin-e Analogs ; Neoadjuvant Chemotherapy ; Multimodal Therapy ; Perioperative Chemotherapy ; Esophagogastric Junction ; Barretts Adenocarcinoma ; Anticancer Agents
ISSN (print) / ISBN
0022-3417
e-ISSN
1096-9896
Journal
Journal of Pathology, The
Quellenangaben
Volume: 230,
Issue: 4,
Pages: 410-419
Publisher
Wiley
Non-patent literature
Publications
Reviewing status
Peer reviewed