The C. elegans excretory canal (EC) cell, which is required for osmoregulation, is a simple model to study biological tube formation, or tubulogenesis1. The EC extends long projections first dorsally, then anteriorly and posteriorly, each with an intra-cellular lumen. Previous genetic analyses have revealed conserved cell biological processes required for EC tubulogenesis1: canal outgrowth requires some genes that also mediate neuronal outgrowth; lumen formation is driven by regulation of cell polarity, polarized vesicular trafficking, and fluid and ion transport; and lumen maintenance depends on the apical actin cytoskeleton. Many of these cell biological processes are also involved in vertebrate angiogenesis2. Moreover, several genes required for EC tubulogenesis, such as
exc-4/Clic,
ccm-3/PDCD10,
gck-3/STK39 and
wnk-1/WNK function in angiogenesis and are linked to vascular disease1, 3-8. Therefore, the EC is a powerful model to identify and characterize novel conserved regulators of angiogenesis. To identify new conserved regulators of EC tubulogenesis we performed a feeding RNAi screen and tested the 249 kinases conserved with humans9. We identified nine conserved kinases that caused EC phenotypes. Among these nine where those previously implicated in EC tubulogenesis (
gck-1,
gck-3,
mrck-1 and
wnk-1)1, indicating a low false-negative rate for the screen. Moreover, RNAi phenotypes of the newly identified kinases were confirmed by genetic mutants, indicating a low false-positive rate. To ask whether these kinases play a role in angiogenesis, we are performing an in vitro angiogenic sprouting assay called FIBA10, which uses human umbilical cord venous endothelial cells (HUVEC) coated onto collagen-dextran beads, embedded in fibrin, and stimulated to develop angiogenic sprouts. Our RNAseq analysis shows that orthologs of all of the kinases identified in our screen are expressed in HUVEC. Currently we are validating lentiviral shRNA clones to knock-down kinase expression in HUVEC, and positive clones will be used to assess the role of kinases in angiogenic sprouting. 1) Sundaram and Buechner, 2016. 2) Betz et al., 2016. 3) Tung et al., 2009. 4) Ulmasov et. al., 2009. 5) Tung and Kitajewski, 2010. 6) Xie et al., 2013. 7) Dbouk et al., 2014. 8) Lai, et al., 2014. 9) Shaye and Greenwald, 2011. 10) Tattersall, et al., 2016.