Objective: Haprolid, a novel compound extracted from Myxobacterium, has been proven to possess selective toxicity towards various tumor cells, effectively inhibiting the growth of hepatocellular carcinoma (HCC). However, the underlying molecular mechanism remains unclear. Methods: To identify differentially expressed proteins (DEPs), isobaric tags for relative and absolute quantitation (iTRAQ) were employed. The clinical significance of DExH-Box Helicase 9 (DHX9) was determined using tissue microarrays in HCC patients. Changes in protein expression were detected using Western blotting, qPCR, and immunohistochemistry. Cell proliferation was evaluated using CCK-8 and crystal violet staining. Cell apoptosis was assessed using Alexa Fluor 647 Annexin V. Xenograft tumor experiments were conducted in animals. Results: iTRAQ screening identified DHX9 as a DEP. DHX9 was discovered to be highly expressed in HCC tissues, correlating with poor prognosis in patients. Haprolid downregulated DHX9 expression, while knockdown of DHX9 suppressed HCC cell proliferation and migration and promoted apoptosis. Meanwhile, overexpression of DHX9 mitigated the inhibitory effect of Haprolid on HCC cells. Knockdown of DHX9 inhibited the AKT signaling pathway, and SC79 reversed the inhibitory effect of DHX9 knockdown on HCC cells. Xenograft experiments confirmed that the knockdown of DHX9 inhibited HCC growth, while the overexpression of DHX9 attenuated the inhibitory effect of Haprolid on HCC growth. Conclusions: Haprolid inhibits the AKT signaling pathway by downregulating DHX9, ultimately suppressing HCC growth. This finding opens up new avenues for targeted HCC therapy.
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