Hemistepsin A Inhibits Cell Proliferation and Induces G0/G1-Phase Arrest, Cellular Senescence and Apoptosis Via the AMPK and p53/p21 Signals in Human Hepatocellular Carcinoma

Abstract

Hemistepsin A (HsA), a natural sesquiterpene lactone isolated from Hemistepta lyrata, has been known as a wide range of anti-tumor effects. The aim of this study was to determine whether HsA suppresses hepatocellular carcinoma (HCC) and to figure out the cellular signaling pathways involved in the anti-HCC activities by experiments using the Huh7 cells (a human HCC cell line) and a xenograft HCC model. In this study, HsA completely inhibited HCC cell proliferation, presumably because it induced G0/G1 cell cycle arrest and mitochondrial-related apoptosis. HsA up-regulated p53, p21, cleaved caspase-3 and cleaved PARP (poly (ADP-ribose) polymerase), but reduced cyclin D, CDK6 and Bcl-2 expressions, and it disrupted mitochondrial membrane potential (ΔΨm). Moreover, phosphorylation of AMP-activated protein kinase (AMPK) was increased by HsA as did the resveratrol and 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR, positive controls). Inhibition of AMPK by using compound C, a competent inhibitor of AMPK, attenuated the loss of ΔΨm, p53 up-regulation and cellular senescence. The efficacy of HsA to reduce HCC cell proliferation, compared to that of other known anti-HCC agents, appears to be similar or slightly better. The anti-tumor effect of HsA was also determined in mice, showing reduced growth of xenografted tumors with no weight loss. Overall, the results suggest that HsA should be considered as a candidate anti-HCC drug.

Hemistepsin A suppresses colorectal cancer growth through inhibiting pyruvate dehydrogenase kinase activity

“…To ensure the in vivo anti-cancer efficacy of HsA, a further extensive study using various types of human cancer cells using in vivo xenograft model should be performed. Second, like other natural products 41 , HsA might bind to the other molecular targets, such as previously reported Nrf2 and NF-κB in inflammation and hepatic fibrosis 42 , 43 , and AMPK in liver cancer 44 . AMPK could be regulated by Acetyl-CoA or ATP production which is regulated by PDK inhibitors 45 , 46 .…”

L-Proline Activates Mammalian Target of Rapamycin Complex 1 and Modulates Redox Environment in Porcine Trophectoderm Cells

“…The preparation of cell lysates and the process of Western blot analysis were performed as previously described [ 41 , 42 ]. Briefly, harvested cells were lysed in ice-cold radioimmunoprecipitation (RIPA) lysis buffer containing 50 mmol/L Tris–HCl (pH 7.4), 150 mmol/L NaCl, 1% NP-40, 0.1% SDS, 1.0 mmol/L PMSF, 1.0 mmol/L Na 3 VO 4 , and a protease inhibitor tablet (Roche, Indianapolis, IN, USA).…”

Compound C Protects Against Cisplatin-Induced Nephrotoxicity Through Pleiotropic Effects

“…It has been demonstrated that P53 was a major factor in AKI by mediating tubular cell apoptosis ( Ying et al, 2014 ; Chen et al, 2016b ; Tang et al, 2019 ). Previous study indicated that activated AMPK suppresses P53 ( Baek et al, 2020 ), other research demonstrated that compound C suppresses P53 activation through inhibition of AMPK ( Jin et al, 2020 ), while another study suggested that compound C could induce P53 expression, phosphorylation and nuclear translocation of the p53 in cancers ( Huang et al, 2013 ; Zhao et al, 2018 ). The current study has provided in vitro and in vivo evidences for the suppressive effect of compound C on P53.…”