Abstract
The absence of biomarkers to accurately predict anticancer therapy response remains a major obstacle in clinical oncology. We applied a genome‐wide loss‐of‐function screening approach in human haploid cells to characterize genetic vulnerabilities to classical microtubule‐targeting agents. Using docetaxel and vinorelbine, two well‐established chemotherapeutic agents, we sought to identify genetic alterations sensitizing human HAP1 cells to these drugs. Despite the fact that both drugs act on microtubules, a set of distinct genes were identified whose disruption affects drug sensitivity. For docetaxel, this included a number of genes with a function in mitosis, while for vinorelbine we identified inactivation of FBXW7,RB1, and NF2, three frequently mutated tumor suppressor genes, as sensitizing factors. We validated these genes using independent knockout clones and confirmed FBXW7 as an important regulator of the mitotic spindle assembly. Upon FBXW7 depletion, vinorelbine treatment led to decreased survival of cells due to defective mitotic progression and subsequent mitotic catastrophe. We show that haploid insertional mutagenesis screens are a useful tool to study genetic vulnerabilities to classical chemotherapeutic drugs by identifying thus far unknown sensitivity factors. These results provide a rationale for investigating patient response to vinca alkaloid‐based anticancer treatment in relation to the mutational status of these three tumor suppressor genes, and could in the future lead to the establishment of novel predictive biomarkers or suggest new drug combinations based on molecular mechanisms of drug sensitivity.
Highlights
Despite major advances in the treatment of disseminated cancers in recent years, treatment failure due to drug resistance remains a major handicap in cancer therapy
Our study demonstrates that docetaxel and vinorelbine, both acting on microtubules, differ in the genetic vulnerabilities they exploit, and that mutations frequently observed in patients with cancer could potentially impact therapy response to a classical chemotherapeutic drug
Our study shows that haploid insertional mutagenesis screens are useful to search for genetic vulnerabilities to classical chemotherapeutic drugs
Summary
Despite major advances in the treatment of disseminated cancers in recent years, treatment failure due to drug resistance remains a major handicap in cancer therapy. There are even patients where the chosen treatment is ineffective and primarily causes side effects. Such unsuccessful treatments might result in the accumulation of pan-resistant cancer cells and patients might lose precious time. To avoid fruitless treatments and instead provide the best regimen for an individual patient, there is an urgent need for better predictive markers which are designed to predict whether a tumor will respond to a particular treatment (Mehta et al, 2010). Known predictive markers include BRCA1/2 mutations for PARP inhibitor.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
