Aneuploidy is associated with poor prognosis in solid tumors. Spontaneous chromosome missegregation events in aneuploid cells promote chromosomal instability (CIN) that may contribute to the acquisition of multidrug resistance in vitro and heighten risk for tumor relapse in animal models. Identification of distinct therapeutic agents that target tumor karyotypic complexity has important clinical implications. To identify distinct therapeutic approaches to specifically limit the growth of CIN tumors, we focused on a panel of colorectal cancer (CRC) cell lines, previously classified as either chromosomally unstable (CIN+) or diploid/near-diploid (CIN−), and treated them individually with a library of kinase inhibitors targeting components of signal transduction, cell cycle, and transmembrane receptor signaling pathways. CIN+ cell lines displayed significant intrinsic multidrug resistance compared with CIN− cancer cell lines, and this seemed to be independent of somatic mutation status and proliferation rate. Confirming the association of CIN rather than ploidy status with multidrug resistance, tetraploid isogenic cells that had arisen from diploid cell lines displayed lower drug sensitivity than their diploid parental cells only with increasing chromosomal heterogeneity and isogenic cell line models of CIN+ displayed multidrug resistance relative to their CIN− parental cancer cell line derivatives. In a meta-analysis of CRC outcome following cytotoxic treatment, CIN+ predicted worse progression-free or disease-free survival relative to patients with CIN− disease. Our results suggest that stratifying tumor responses according to CIN status should be considered within the context of clinical trials to minimize the confounding effects of tumor CIN status on drug sensitivity. Cancer Res; 71(5); 1858–70. ©2011 AACR.

Microtubule-stabilizing (MTS) agents, such as taxanes, are important chemotherapeutics with a poorly understood mechanism of action. We identified a set of genes repressed in multiple cell lines in response to MTS agents and observed that these genes are overexpressed in tumors exhibiting chromosomal instability (CIN). Silencing 22/50 of these genes, many of which are involved in DNA repair, caused cancer cell death, suggesting that these genes are involved in the survival of aneuploid cells. Overexpression of these “CIN-survival” genes is associated with poor outcome in estrogen receptor–positive breast cancer and occurs frequently in basal-like and Her2-positive cases. In diploid cells, but not in chromosomally unstable cells, paclitaxel causes repression of CIN-survival genes, followed by cell death. In the OV01 ovarian cancer clinical trial, a high level of CIN was associated with taxane resistance but carboplatin sensitivity, indicating that CIN may determine MTS response in vivo. Thus, pretherapeutic assessment of CIN may optimize treatment stratification and clinical trial design using these agents.

The SARS-CoV-2 pandemic significantly affected oncology practice across the globe. There is uncertainty as to the contribution of patients9 demographics and oncologic features to severity and mortality from COVID-19 and little guidance as to the role of anticancer and anti–COVID-19 therapy in this population. In a multicenter study of 890 patients with cancer with confirmed COVID-19, we demonstrated a worsening gradient of mortality from breast cancer to hematologic malignancies and showed that male gender, older age, and number of comorbidities identify a subset of patients with significantly worse mortality rates from COVID-19. Provision of chemotherapy, targeted therapy, or immunotherapy did not worsen mortality. Exposure to antimalarials was associated with improved mortality rates independent of baseline prognostic factors. This study highlights the clinical utility of demographic factors for individualized risk stratification of patients and supports further research into emerging anti–COVID-19 therapeutics in SARS-CoV-2–infected patients with cancer. Significance: In this observational study of 890 patients with cancer diagnosed with SARS-CoV-2, mortality was 33.6% and predicted by male gender, age ≥65, and comorbidity burden. Delivery of cancer therapy was not detrimental to severity or mortality from COVID-19. These patients should be the focus of shielding efforts during the SARS-CoV-2 pandemic. This article is highlighted in the In This Issue feature, p. 1426

The centrosome acts as a centre for microtubule organisation and plays crucial roles in cell polarity, migration, growth and division. Cep131 has recently been described as a basal body component essential for cilium formation, though its function in non-ciliogenic cells is unknown. We identified human Cep131 in a screen for regulators of genome stability. We show that centrosomal localisation of Cep131 is cell cycle-regulated and requires both an intact microtubule network and a functional dynein-dynactin transport system. Cep131 is recruited to centriolar satellites by PCM1, and localised to the centriolar core region by both pericentrin and Cep290. Depletion of Cep131 results in a reduction in proliferation rate, centriole amplification, an increased frequency of multipolar mitosis, chromosomal instability, and an increase in post-mitotic DNA damage. These data therefore highlight the importance of human Cep131 for maintaining genomic integrity.