HMBOX1 plays a critical role in plumbagin-induced growth inhibition of hepatocellular carcinoma cells.

Hepatocellular carcinoma (HCC) is one of the commonly lethal malignancies worldwide and represents a major global health-care challenge. We have previously demonstrated that plumbagin (PLB) could inhibit the development of tumor in liver, but the mechanism is still not fully clear. Here we identified a transcription repressor-homeobox containing 1 (HMBOX1) as a regulator in the development of HCC.Knockdown of HMBOX1 resulted into expansive of tumor cells, while overexpression led to growth inhibition. Mechanistically, PLB promoted HMBOX1 expression, leading to inactivation of PI3K/Akt-mTOR of liver cancer cells. Moreover, PLB also inhibited tumor formation in a xenograft transplantation model via PI3K/Akt/mTOR signaling. Collectively, our results suggested that HMBOX1 played a key role in PLB-induced inhibition of HCC growth through PI3K/Akt/mTOR signaling pathway.