Antitumor Effect of Morusin via G1 Arrest and Antiglycolysis by AMPK Activation in Hepatocellular Cancer

Abstract

Though Morusin isolated from the root of Morus alba was known to have antioxidant, anti-inflammatory, antiangiogenic, antimigratory, and apoptotic effects, the underlying antitumor effect of Morusin is not fully understood on the glycolysis of liver cancers. Hence, in the current study, the antitumor mechanism of Morusin was explored in Hep3B and Huh7 hepatocellular carcninomas (HCC) in association with glycolysis and G1 arrest. Herein, Morusin significantly reduced the viability and the number of colonies in Hep3B and Huh7 cells. Moreover, Morusin significantly increased G1 arrest, attenuated the expression of cyclin D1, cyclin D3, cyclin E, cyclin-dependent kinase 2 (CDK2), cyclin-dependent kinase 4 (CDK4), and cyclin-dependent kinase 6 (CDK6) and upregulated p21 and p27 in Hep3B and Huh7 cells. Interestingly, Morusin significantly activated phosphorylation of the adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC) but attenuated the expression of the p-mammalian target of protein kinase B (AKT), rapamycin (mTOR), c-Myc, hexokinase 2(HK2), pyruvate kinases type M2 (PKM2), and lactate dehydrogenase (LDH) in Hep3B and Huh7 cells. Consistently, Morusin suppressed lactate, glucose, and adenosine triphosphate (ATP) in Hep3B and Huh7 cells. Conversely, the AMPK inhibitor compound C reduced the ability of Morusin to activate AMPK and attenuate the expression of p-mTOR, HK2, PKM2, and LDH-A and suppressed G1 arrest induced by Morusin in Hep3B cells. Overall, these findings suggest that Morusin exerts an antitumor effect in HCCs via AMPK mediated G1 arrest and antiglycolysis as a potent dietary anticancer candidate.

Cancer metabolism control by natural products: Pyruvate kinase M2 targeting therapeutics

“…The underlying anticancer effect of morusin is not fully understood in liver cancers. Hence, in the study by Cho et al (2021), the authors investigated the anticancer mechanism of morusin against hepatocellular carcinoma (Hep3B and Huh7) in association with glycolysis. Consistently, morusin suppressed lactate, glucose, and ATP production in Hep3B and Huh7 cells, leading to cell death.…”

Natural products targeting glycolytic signaling pathways-an updated review on anti-cancer therapy

“…Oroxylin A might block the production of polypyrimidine tract-binding protein and increase the ratio of PKM1/PKM2 in HepG2 and SMMC-7721 hepatoma cells ( Wei et al, 2017 ). Morusin significantly induced AMPK/ACC phosphorylation and suppressed p-AKT, p-mTOR, c-Myc, HK2, PKM2, and LDH gene expression in hepatocellular carcinoids Huh7 and Hep3B cells, consequently exerting anticancer effects via AMPK-mediated G1 arrest ( Cho et al, 2021 ). In five primary HCC cell lines, PB2 disrupted the PKM2/HSP90/HIF-1α connection by reducing PKM2 production and nuclear translocation, thereby inducing cell death via HIF-1α-mediated transcriptional repression ( Feng et al, 2019 ).…”

Natural products targeting glycolysis in cancer

“…Lily saponin monomer 13, a saponin monomer derived from lily flower, suppresses colorectal cancer cell proliferation by activating the AMPK pathway and blocking GLUT1 ( Wei et al, 2019 ). Morusin, isolated from the root of morus alba, significantly activated phosphorylation of AMPK/acetyl-CoA carboxylase, but attenuated the expression of the mammalian target of AKT, mTOR, c-MYC, HK2, PKM2, and LDH in Hep3B and Huh7 cells ( Cho et al, 2021 ).…”

“…Polyphenols are a complex class of plant secondary metabolites consisting of an aromatic ring with at least one hydroxyl group, such as phenolic acids, cinnamic acids, coumarins, flavonoids, xanthones and stilbenes, comprised phenolic groups. Phenolic compounds, like quercetin ( Jia et al, 2018 ), curcumin ( Man et al, 2020 ), morusin ( Cho et al, 2021 ), epigallocatechin gallate ( Chen et al, 2022a ), oleuropein ( Ruzzolini et al, 2020 ), inhibit glucose and lactate cellular uptake, downregulate PKM2 and GLUT1 expression, and inhibit MCT1-mediated lactate reuptake in cancer treatments. Polyphenols, such resveratrol ( Brockmueller et al, 2021b ), salvianolic acid B ( Wei et al, 2018a ), and morusin ( Cho et al, 2021 ), regulate glycolysis by down-regulating PI3K and AKT expression.…”

“…Phenolic compounds, like quercetin ( Jia et al, 2018 ), curcumin ( Man et al, 2020 ), morusin ( Cho et al, 2021 ), epigallocatechin gallate ( Chen et al, 2022a ), oleuropein ( Ruzzolini et al, 2020 ), inhibit glucose and lactate cellular uptake, downregulate PKM2 and GLUT1 expression, and inhibit MCT1-mediated lactate reuptake in cancer treatments. Polyphenols, such resveratrol ( Brockmueller et al, 2021b ), salvianolic acid B ( Wei et al, 2018a ), and morusin ( Cho et al, 2021 ), regulate glycolysis by down-regulating PI3K and AKT expression. Curcumin ( Siddiqui et al, 2018a ) decreases the Warburg effect through decreasing the expression of mTOR in cancer cells.…”