The Hippo pathway kinase LATS1 scaffolds Beclin1 in autophagy regulation in hepatocellular carcinoma

Autophagy perturbation represents an emerging therapeutic strategy in cancer. The mammalian Hippo pathway is an evolutionary conserved tumor suppressive network, where the kinases LATS1/2 phosphorylate and inactivate oncogenic YAP/TAZ. Here, we demonstrated a pro-survival role of LATS1, but not LATS2, in hepatocellular carcinoma cells in response to sorafenib, a standard care of advanced HCC. Transcriptomic analysis revealed a restrictive role of LATS1 in autophagy regulation in HCC cells. Further, we found that the autophagy regulation by LATS1 was independent of its kinase activity. Instead, LATS1 stabilized autophagy core-machinery component Beclin 1 via promoting a non-canonical form of K27-linked ubiquitination, and consequently, inactive Beclin 1 self-dimer, in a E3 ligase NEDD4 dependent manner. Our study highlights a functional diversity between LATS1 and LATS2 and uncovers a scaffolding role of LATS1 in mediating a cross-talk between Hippo signalling and autophagy in HCC and therapy response. Overall design: We performed RNA-sequencing of 3 replicates of 3 different cell lines.