Delineation of the oncogenic potential of AKT downstream targets in murine and human hepatocellular carcinoma

Aberrant activation of AKT is a key oncogenic driver in hepatocellular carcinoma (HCC). As AKT activates multiple downstream signaling pathways, the key mechanisms mediating AKT-driven tumorigenesis must be elucidated to develop optimal treatment strategies. Using an Akt/NRas-induced HCC mouse model, we found that AKT promotes tumorigenesis by targeting TSC2 and GSK3a&ß rather than FOXO family members. Loss of either TSC2, leading to mTORC1 activation, or both GSK3 isoforms cooperated with activated NRAS to promote HCC formation in vivo, albeit with different latencies. Simultaneous TSC2 and GSK3a&ß deletion cooperated with NRAS to rapidly induce HCC formation, mirroring observations from the Akt/NRas HCC model. RNA-seq studies indicated distinct pathways regulated by TSC2/mTORC1 and GSK3a&ß during hepatocarcinogenesis, with FOXM1 functioning as a major effector of GSK3. In summary, these findings uncover AKT's role in suppressing the TSC complex and GSK3 to drive HCC, offering mechanistic insights into oncogenic signaling and potential therapeutic targets. Overall design: RNA-seq profilling of normal liver (NL) and liver tumor tissues from Akt/NRas-, Tsc2-/-/NRas-, sgGSK3a&ß/NRas-, and Tsc2-/-/sgGSK3a&ß/NRas-induced murine liver tumor models.