Identifying novel and druggable targets in a triple negative breast cancer cell line using the Invitrogen™ LentiArray™ Human Kinase CRISPR Library

（発表は日本語で行います。）

Breast cancer is the most commonly diagnosed cancer among women in worldwide and the second leading cause of death by cancer after lung cancer. Breast cancer can be broadly grouped into three main groups: HR+ (estrogen receptor positive and/or progesterone receptor positive), HER2+ (human epidermal growth factor receptor 2 positive) and triple-negative (HR- and HER2-). Hormone and anti-HER2 targeted therapies are available for receptor positive breast cancer types. However, since triple negative breast cancer (TNBC) does not have estrogen, progesterone or HER2 receptors, there are no such targeted therapies available for this type of cancer. Currently, oncologists are resort to treating TNBC patients with traditional chemotherapy drugs, surgery and radiation. Thus, due its limited treatment options and poor prognosis, search for specific molecular targets and developing novel treatments for TNBC is one of the highest priorities of current breast cancer research.

In this study, we developed a CRISPR/Cas9-based high throughput loss-of-function screen for identifying target genes responsible for the tumor proliferation and growth in TNBC. Our initial focus was to identify essential kinases in MDA-MB-231 cell line using the Invitrogen™ LentiArray™ Human Kinase CRISPR Library, which targets 840 kinases with up to 4 different gRNAs per protein kinase for complete gene knockout. This functional screen identified over 90 protein kinases that are essential for cell viability and cell proliferation. Ten of these hits (CDK1, CDK2, CDK8, CDK10, CDK11A, CDK19, CDK19, CDC7, EPHA2 and WEE1) are well-known targets validated in the literature. Currently, we are in the process validating the novel hits through target gene sequencing, western blotting and target specific small molecule kinase inhibitors.