Chemoresistance is mediated by ovarian cancer leader cells in vitro

• Published in: Journal of experimental & clinical cancer research 2021-09, Vol.40 (1), p.276-276, Article 276
• Main Authors: Karimnia, Nazanin, Wilson, Amy L, Green, Emma, Matthews, Amelia, Jobling, Thomas W, Plebanski, Magdalena, Bilandzic, Maree, Stephens, Andrew N
• Format: Article
• Language: English
• Subjects: Antineoplastic Agents - therapeutic use; Apoptosis; Automation; Cancer; Cancer therapies; Cell growth; Cell Line, Tumor; Cell Proliferation; Chemo-resistance; Chemotherapy; Cisplatin - therapeutic use; Clustered Regularly Interspaced Short Palindromic Repeats; CRISPR; Diseases; DNA Replication; Drug Resistance, Neoplasm; Experiments; Female; Flow cytometry; Gene expression; Green Fluorescent Proteins - genetics; Humans; Keratin-14; Keratin-14 - metabolism; Leader cells; Microscopy; Ovarian Cancer; Ovarian Neoplasms - drug therapy; Ovarian Neoplasms - genetics; Ovarian Neoplasms - metabolism; Ovarian Neoplasms - pathology; Recurrence; Relapse; Spheroids; Stem cells
• ISSN: 1756-9966; 0392-9078; 1756-9966
• DOI: 10.1186/s13046-021-02086-3

Leader cells are a subset of cancer cells that coordinate the complex cell-cell and cell-matrix interactions required for ovarian cancer migration, invasion, tumour deposition and are negatively associated with progression-free survival and response to therapy. Emerging evidence suggests leader cells may be enriched in response to chemotherapy, underlying disease recurrence following treatment. CRISPR was used to insert a bicistronic T2A-GFP cassette under the native KRT14 (leader cell) promoter. 2D and 3D drug screens were completed in the presence of chemotherapies used in ovarian cancer management. Leader cell; proliferative (Ki67); and apoptotic status (Cleaved Caspase 3) were defined by live cell imaging and flow cytometry. Quantitative real-time PCR defined "stemness" profiles. Proliferation was assessed on the xCELLigence real time cell analyser. Statistical Analysis was performed using unpaired non-parametric t-tests or one-way ANOVA and Tukey's multiple comparison post hoc. Leader cells represent a transcriptionally plastic subpopulation of ovarian cancer cells that arise independently of cell division or DNA replication, and exhibit a "stemness" profile that does not correlate with epithelial-to-mesenchymal transition. Chemotherapeutics increased apoptosis-resistant leader cells in vitro, who retained motility and expressed known chemo-resistance markers including ALDH1, Twist and CD44v6. Functional impairment of leader cells restored chemosensitivity, with leader cell-deficient lines failing to recover following chemotherapeutic intervention. Our data demonstrate that ovarian cancer leader cells are resistant to a diverse array of chemotherapeutic agents, and are likely to play a critical role in the recurrence of chemo-resistant disease as drivers of poor treatment outcomes.