p-MEK expression predicts prognosis of patients with adenocarcinoma of esophagogastric junction (AEG) and plays a role in anti-AEG efficacy of Huaier.

The incidence rate of adenocarcinoma of the esophagogastric junction (AEG) is increasing worldwide with poor prognosis and unclear pathogenesis. Trametes robiniophila Murr. (Huaier), a traditional Chinese medicine has been used in the clinical treatment of a variety of solid tumors, including AEG. However, its anticancer components and molecular mechanisms are still unclear. In our previous studies, we have found that Huaier n-butanol extract (HBE) shows the most potent anticancer activity among different extracts. In the present study, we aimed to investigate the clinical relevance of p-MEK expression in AEG patients and the role of the MEK/ERK signaling pathway in the anti-AEG efficacy of HBE in vitro and in vivo. We herein demonstrate that p-MEK expression in AEG tissues was significantly higher than that in paracancerous tissues and correlated with a poor prognosis in AEG patients. We further found that HBE inhibited the colony formation, migration, and invasion in AEG cell lines in a concentration-dependent manner in vitro. HBE also suppressed the growth of AEG xenograft tumors without causing any host toxicity in vivo. Mechanistically, HBE caused the inactivation of the MEK/ERK signaling pathway by dephosphorylating MEK1 at S298, ERK1 at T202, and ERK2 at T185 and modulating the expression of EMT-related proteins. In summary, our results demonstrate that the high expression of p-MEK may be an independent factor of poor prognosis in patients with AEG. The clinically used anticancer drug Huaier may exert its anti-AEG efficacy by inhibiting the MEK/ERK signaling pathway.

Miltirone induces cell death in hepatocellular carcinoma cell through GSDME-dependent pyroptosis.

Pyroptosis is a form of programmed cell death, and recently described as a new molecular mechanism of chemotherapy drugs in the treatment of tumors. Miltirone, a derivative of phenanthrene-quinone isolated from the root of Salvia miltiorrhiza Bunge, has been shown to possess anti-cancer activities. Here, we found that miltirone inhibited the cell viability of either HepG2 or Hepa1-6 cells, and induced the proteolytic cleavage of gasdermin E (GSDME) in each hepatocellular carcinoma (HCC) cell line, with concomitant cleavage of caspase 3. Knocking out GSDME switched miltirone-induced cell death from pyroptosis to apoptosis. Additionally, the induction effects of miltirone on GSDME-dependent pyroptosis were attenuated by siRNA-mediated caspase three silencing and the specific caspase three inhibitor Z-DEVD-FMK, respectively. Miltirone effectively elicited intracellular accumulation of reactive oxygen species (ROS), and suppressed phosphorylation of mitogen-activated and extracellular signal-regulated kinase (MEK) and extracellular regulated protein kinases 1/2 (ERK1/2) for pyroptosis induction. Moreover, miltirone significantly inhibited tumor growth and induced pyroptosis in the Hepa1-6 mouse HCC syngeneic model. These results provide a new insight that miltirone is a potential therapeutic agent for the treatment of HCC via GSDME-dependent pyroptosis.

P-AKT2/SPK1 (P-SPK1) and P-MEK/P-ERK cell signaling pathways are involved in LPS-induced macrophage migration.

Macrophage recruitment to the inflammation site is essential for LPS-induced myocarditis, although the underlying mechanism remains elusive. This study was designed to examine the role of the P-AKT2/SPK1 (P-SPK1) and P-MEK/P-ERK signaling cascades in the regulation of macrophage migration and LPS-induced myocarditis. Our data revealed that (1) the P-AKT2/SPK1 (P-SPK1) and P-MEK/P-ERK signaling cascades acted separately in the regulation of macrophage migration; (2) P-AKT2/SPK1 (P-SPK1) played a relatively important role compared to P-MEK/P-ERK cell signaling in LPS-induced macrophage migration; (3) atorvastatin (ATV) inhibited macrophage migration by inhibiting P-AKT2/SPK1 (P-SPK1) cell signaling, but ATV could increase P-MEK and P-ERK protein expression; (4) ATV has a beneficial effect on LPS-induced myocarditis via inhibition of P-AKT2/SPK1-mediated macrophage recruitment, apoptosis, TNFα, IL-1ß, and IL-6; (5) ATV-offered protection against LPS-induced myocarditis was eliminated from SPK1-KO mice; (6) SPK1 may play a harmful role in LPS-induced myocarditis. Taken together, our data revealed that SPK1 represents a novel regulating factor for macrophage migration and cardiac protection under LPS-induced myocarditis.