title: Short-term expansion of breast circulating cancer cells predicts response to anti-cancer therapy.
abstract: Circulating tumor cells (CTCs) are considered as surrogate markers for prognosticating and evaluating patient treatment responses. Here, 226 blood samples from 92 patients with breast cancer, including patients with newly diagnosed or metastatic refractory cancer, and 16 blood samples from healthy subjects were cultured in laser-ablated microwells. Clusters containing an increasing number of cytokeratin-positive (CK+) cells appeared after 2 weeks, while most blood cells disappeared with time. Cultures were heterogeneous and exhibited two distinct sub-populations of cells: 'Small' (≤ 25 μm; high nuclear/cytoplasmic ratio; CD45-) cells, comprising CTCs, and 'Large' (> 25 μm; low nuclear/cytoplasmic ratio; CD68+ or CD56+) cells, corresponding to macrophage and natural killer-like cells. The Small cell fraction also showed copy number increases in six target genes (FGFR1, Myc, CCND1, HER2, TOP2A and ZNF217) associated with breast cancer. These expanded CTCs exhibited different proportions of epithelial-mesenchymal phenotypes and were transferable for further expansion as spheroids in serum-free suspension or 3D cultures. Cluster formation was affected by the presence and duration of systemic therapy, and its persistence may reflect therapeutic resistance. This novel and advanced method estimates CTC clonal heterogeneity and can predict, within a relatively short time frame, patient responses to therapy.
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore.
authors.forename: Bee Luan
authors.initials: BL
authors.lastname: Khoo
authors.affiliation: Department of Hematology-Oncology, National University Cancer Institute, National University Hospital, Singapore.|Cancer Science Institute of Singapore, National University of Singapore, Singapore.
authors.forename: Soo Chin
authors.initials: SC
authors.lastname: Lee
authors.affiliation: Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Singapore.
authors.forename: Prashant
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Cancer Science Institute of Singapore, National University of Singapore, Singapore.
authors.forename: Tuan Zea
authors.initials: TZ
authors.lastname: Tan
authors.affiliation: BioSystems and Micromechanics (BioSyM) IRG, Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore.|School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, Australia.
authors.forename: Majid Ebrahimi
authors.initials: ME
authors.lastname: Warkiani
authors.affiliation: Department of Hematology-Oncology, National University Cancer Institute, National University Hospital, Singapore.
authors.forename: Samuel G W
authors.initials: SG
authors.lastname: Ow
authors.affiliation: Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Singapore.
authors.forename: Sayantani
authors.initials: S
authors.lastname: Nandi
authors.affiliation: Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Singapore.|BioSystems and Micromechanics (BioSyM) IRG, Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore.|Department of Biomedical Engineering, National University of Singapore, Singapore.|Department of Mechanical Engineering, National University of Singapore, Singapore.
authors.forename: Chwee Teck
authors.initials: CT
authors.lastname: Lim
authors.affiliation: Cancer Science Institute of Singapore, National University of Singapore, Singapore.|Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Singapore.|Department of Biochemistry Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Thiery
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000097:blood*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D003520:Cyclophosphamide / Q000627:therapeutic use; D004317:Doxorubicin / Q000627:therapeutic use; D019008:Drug Resistance, Neoplasm; D058750:Epithelial-Mesenchymal Transition / Q000502:physiology; D005260:Female; D018628:Gene Dosage / Q000235:genetics; D006801:Humans; D007211:Indoles / Q000627:therapeutic use; D007633:Keratins / Q000378:metabolism; D061986:MCF-7 Cells; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D011758:Pyrroles / Q000627:therapeutic use; D018874:Spheroids, Cellular / Q000473:pathology; D000077210:Sunitinib; D016896:Treatment Outcome; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D007211:Indoles; D011758:Pyrroles; D007633:Keratins; D004317:Doxorubicin; D003520:Cyclophosphamide; D000077210:Sunitinib
keywords: CTCs; breast cancer; circulating tumor cells; enrichment