Myricitrin, a naturally occurring polyphenol hydroxy flavonoid, has been reported to possess anti‐inflammatory properties. However, the precise molecular mechanism of myricitrin’s effects on LPS‐induced inflammation is unclear. In the present study, myricitrin significantly alleviated acute lung injury in mice. Myricitrin also markedly suppressed the production of NO, TNF‐α, IL‐6, and MCP‐1 in RAW264.7 macrophage cells. The inhibition of NO was concomitant with a decrease in the protein and mRNA levels of iNOS. The phosphorylation of JAKs and STAT‐1 was abrogated by myricitrin. Furthermore, myricitrin inhibited the nuclear transfer and DNA binding activity of STAT1. The JAK‐specific inhibitor ruxolitinib simulated the anti‐inflammatory effect of myricitrin. However, myricitrin had no impact on the MAPK signalling pathway. Myricitrin attenuated the generation of intracellular ROS by inhibiting the assembly of components of the gp91^phox and p47^phox. Suppression of ROS generation using NAC or apocynin or by silencing gp91^phox and p47^phox all demonstrated that decreasing the level of ROS inhibited the LPS‐induced inflammatory response. Collectively, these results confirmed that myricitrin exhibited anti‐inflammatory activity by blocking the activation of JAKs and the downstream transcription factor STAT1, which may result from the downregulation of NOX2‐dependent ROS production mediated by myricitrin.

HMGB1, a highly conserved nonhistone DNA‐binding protein, plays an important role in inflammatory diseases. Once released to the extracellular space, HMGB1 acts as a proinflammatory cytokine that triggers inflammatory reaction. Our previous study showed that salidroside exerts anti‐inflammatory effect via inhibiting the JAK2‐STAT3 signalling pathway. However, whether salidroside inhibits the release of HMGB1 is still unclear. In this study, we aim to study the effects of salidroside on HMGB1 release and then investigate the potential molecular mechanisms. In an experimental rat model of sepsis caused by CLP, salidroside administration significantly attenuated lung injury and reduced the serum HMGB1 level. In RAW264.7 cells, we investigated the effects of salidroside on LPS‐induced HMGB1 release and then explored the underlying molecular mechanisms. We found that salidroside significantly inhibited LPS‐induced HMGB1 release, and the inhibitory effect was correlated with the HMGB1 acetylation levels. Mechanismly, salidroside inhibits HMGB1 acetylation through the AMPK‐SirT1 pathway. In addition, SirT1 overexpression attenuated LPS‐induced HMGB1 acetylation and nucleocytoplasmic translocation. Furthermore, in SirT1 shRNA plasmid‐transfected cells, salidroside treatment enhanced SirT1 expression and reduced LPS‐activated HMGB1 acetylation and nucleocytoplasmic translocation. Collectively, these results demonstrated that salidroside might reduce HMGB1 release through the AMPK‐SirT1 signalling pathway and suppress HMGB1 acetylation and nucleocytoplasmic translocation.

High-mobility group box 1 (HMGB1), a highly conserved chromosome protein, is considered as a potential therapeutic target and novel biomarker because of its regulation in the proliferation and metastasis of Hepatocellular carcinoma (HCC). Calenduloside E (CE), a natural active product, has been reported to anti-cancer effect. However, the role and underlying molecular mechanism of CE in HCC is still unclear. The purpose of this study is to investigate the effects of CE on the proliferation and migration of HCC, and then explore the possible underlying molecular mechanism. HepG2 cells were treated with CE or transfected with HMGB1 shRNA plasmids, EdU and colony formation assays were used to detect cell proliferation ability. Wound healing and transwell assays were used to determine the role of CE in cell migration. The expression of Cyclins, PCNA, MMPs, HMGB1, N-cadherin, E-cadherin and phosphorylation of p38, ERK and JNK were all detected using Western blotting. Our results showed that CE inhibited HepG2 cells proliferation and migration in a dose dependent manner; reduced the expression levels of Cycins, PCNA, HMGB1, MMPs and N-cadherin; up-regulated E-cadherin expression; enhanced the phosphorylation of p38 and JNK signalling pathways. Blocking the activation of p38 and JNK obviously reversed CE-mediated inhibitory effects on HepG2 cell proliferation and migration; reversed CE-induced down-regulation of Cyclins, PCNA, MMPs, N-cadherin and HMGB1, as well as E-cadherin up-regulation. In conclusion, our study suggested that CE reduces the expression levels of Cyclins, MMPs and epithelial-mesenchymal transformation (EMT) through p38/JNK-HMGB1 signaling axis and then inhibits HepG2 cells proliferation and migration in HepG2 cells. This study provides a new perspective for the anti-tumour molecular mechanism of CE in HCC.

Gastric cancer (GC) is a common malignancy tumour in China. Despite various therapeutic approaches to improve the survival rate of GC patients, the effectiveness of currently available treatments remains unsatisfactory. High mobility group box 1 (HMGB1) is reported to play a role in tumour development. However, the molecular mechanisms involved in HMGB1-mediated regulation of proliferation and migration of GC cells remain unclear. In the present study, we demonstrated that HMGB1 is highly expressed in GC cells and tissue. In HGC-27 GC cells, HMGB1 overexpression or HMGB1 RNA interference both demonstrated that HMGB1 could promote GC cell proliferation and migration. Investigation of the underlying molecular mechanisms revealed that HMGB1 enhanced cyclins expression, induced epithelial-to-mesenchymal transition and matrix metalloproteinase (MMPs) expression and promoted RAGE expression as well as RAGE-mediated activation of Akt/mTOR/P70S6K and ERK/P90RSK/CREB signalling pathways. We also found that inhibition of ERK and mTOR using specific inhibitors reduced recombinant human HMGB1-induced RAGE expression, suggesting that the RAGE-mTOR/ERK positive feedback loop is involved in HMGB1-induced GC cell proliferation and migration. Our study highlights a novel mechanism by which HMGB1 promotes GC cell proliferation and migration via RAGE-mediated Akt-mTOR and ERK-CREB signalling pathways which also involves the RAGE-mTOR/ERK feedback loop. These findings indicate that HMGB1 is a potential therapeutic target for GC.

Background: Lactate dehydrogenase (LDHs) is an enzyme involved in anaerobic glycolysis, including LDHA, LDHB, LDHC and LDHD. Given the regulatory role in the biological progression of certain tumors, we analyzed the role of LDHs in pan-cancers. Methods: Cox regression, Kaplan–Meier curves, Receiver Operating Characteristic (ROC) curves, and correlation of clinical indicators in tumor patients were used to assess the prognostic significance of LDHs in pan-cancer. The TCGA, HPA, TIMER, UALCAN, TISIDB, and Cellminer databases were used to investigate the correlation between the expression of LDHs and immune subtypes, immune checkpoint genes, methylation levels, tumor mutational load, microsatellite instability, tumor-infiltrating immune cells and drug sensitivity. The cBioPortal database was also used to identify genomic abnormalities of LDHs in pan-cancer. A comprehensive assessment of the biological functions of LDHs was performed using GSEA. In vitro, HepG2 and Huh7 cells were transfected with LDHD siRNA and GFP-LDHD, the proliferation capacity of cells was examined using CCK-8, EdU, and colony formation assays; the migration and invasion of cells was detected by wound healing and transwell assays; western blotting was used to detect the levels of MMP-2, MMP-9, E-cadherin, N-cadherin and Akt phosphorylation. Results: LDHs were differentially expressed in a variety of human tumor tissues. LDHs subtypes can act as pro-oncogenes or anti-oncogenes in different types of cancer and have an impact on the prognosis of patients with tumors by influencing their clinicopathological characteristics. LDHs were differentially expressed in tumor immune subtypes and molecular subtypes. In addition, LDHs expression correlated with immune checkpoint genes, tumor mutational load, and microsatellite instability. LDHD was identified to play an important role in the prognosis of HCC patients, according to a comprehensive analysis of LDHs in pan-cancer. In HepG2 and Huh7 cells, knockdown of LDHD promoted cell proliferation, migration, and invasion, promoted the protein expression levels of MMP-2, MMP-9, N-cadherin, and Akt phosphorylation, but inhibited the protein expression level of E-cadherin. In addition, LDHD overexpression showed the opposite changes. Conclusion: LDHs subtypes can be used as potential prognostic markers for certain cancers. Prognostic and immunotherapeutic analysis indicated that LDHD plays an important role in the prognosis of HCC patients. In vitro experiments revealed that LDHD can affect HCC proliferation, migration, and invasion by regulating MMPs expression and EMT via Akt signaling pathway, which provides a new perspective on the anti-cancer molecular mechanism of LDHD in HCC.