Improving breast cancer sensitivity to paclitaxel by increasing aneuploidy

Sylvie Rodrigues-Ferreira (1, 2, 3) , Anne Nehlig (1, 2, 3) , Hadia Moindjie (1, 2, 3) , Clarisse Monchecourt (1, 2, 3) , Cynthia Seiler (1, 2, 3) , Elisabetta Marangoni (4, 5) , Sophie Chateau-Joubert (6) , Marie-Eglantine Dujaric (4, 5, 7) , Nicolas Servant (8) , Bernard Asselain (4, 5, 7) , Patricia de Cremoux (9) , Magali Lacroix-Triki (10) , Monica Arnedos (11) , Jean-Yves Pierga (12, 4, 13, 14) , Fabrice André (11, 1, 2) , Clara Nahmias (1, 2, 3)

1 U981 - Biomarqueurs prédictifs et nouvelles stratégies moléculaires en thérapeutique anticancéreuse
2 LabEx LERMIT - Laboratoire d'Excellence en Recherche sur le Médicament et l'Innovation Thérapeutique [Châtenay-Malabry]
3 IGR - Institut Gustave Roussy
4 Institut Curie [Paris]
5 PSL - Université Paris sciences et lettres
6 Biopôle Alfort
7 Mines Paris - PSL (École nationale supérieure des mines de Paris)
8 Cancer et génome: Bioinformatique, biostatistiques et épidémiologie d'un système complexe
9 AP-HP - Hopital Saint-Louis [AP-HP]
10 Département de biologie et pathologie médicales [Gustave Roussy]
11 Département de médecine oncologique [Gustave Roussy]
12 UPD5 - Université Paris Descartes - Paris 5
13 USPC - Université Sorbonne Paris Cité
14 Hôpital René Huguenin [Saint-Cloud]

Predictive biomarkers for tumor response to neoadjuvant chemotherapy are needed in breast cancer. This study investigates the predictive value of 280 genes encoding proteins that regulate microtubule assembly and function. By analyzing 3 independent multicenter randomized cohorts of breast cancer patients, we identified 17 genes that are differentially regulated in tumors achieving pathological complete response (pCR) to neoadjuvant chemotherapy. We focused on the MTUS1 gene, whose major product, ATIP3, is a microtubule-associated protein down-regulated in aggressive breast tumors. We show here that low levels of ATIP3 are associated with an increased pCR rate, pointing to ATIP3 as a predictive biomarker of breast tumor chemosensitivity. Using preclinical models of patient-derived xenografts and 3-dimensional models of breast cancer cell lines, we show that low ATIP3 levels sensitize tumors to the effects of taxanes but not DNA-damaging agents. ATIP3 silencing improves the proapoptotic effects of paclitaxel and induces mitotic abnormalities, including centrosome amplification and multipolar spindle formation, which results in chromosome missegregation leading to aneuploidy. As shown by time-lapse video microscopy, ATIP3 depletion exacerbates cytokinesis failure and mitotic death induced by low doses of paclitaxel. Our results favor a mechanism by which the combination of ATIP3 deficiency and paclitaxel treatment induces excessive aneuploidy, which in turn results in elevated cell death. Together, these studies highlight ATIP3 as an important regulator of mitotic integrity and a useful predictive biomarker for a population of chemoresistant breast cancer patients.

Mots clés: ATIP3; MTUS1; multipolar spindle; predictive biomarker; taxanes.

Domaines: Sciences du Vivant [q-bio]; Cancer; Médecine humaine et pathologie; Biologie cellulaire; Organisation et fonctions cellulaires [q-bio.SC]

Sylvie Rodrigues-Ferreira, Anne Nehlig, Hadia Moindjie, Clarisse Monchecourt, Cynthia Seiler, et al.. Improving breast cancer sensitivity to paclitaxel by increasing aneuploidy. Proceedings of the National Academy of Sciences of the United States of America, 2019, 116 (47), pp.23691-23697. ⟨10.1073/pnas.1910824116⟩. ⟨hal-02411561⟩