Cepharanthine Suppresses Herpes Simplex Virus Type 1 Replication Through the Downregulation of the PI3K/Akt and p38 MAPK Signaling Pathways

Cepharanthine (CEP) is a naturally occurring isoquinoline alkaloid extracted from Stephania cepharantha Hayata. Although its underlying molecular mechanism is not fully understood, this compound is reported as a promising antiviral drug. In the present study, we explore the anti-HSV-1 effects and the underlying molecular mechanisms of CEP in vitro. Our results show that CEP could significantly inhibit the formation of plaque and the expression of viral proteins and exhibit a general suppression of replication-associated genes. Whereas HSV-1 infection increases the expressions of phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), and p38 mitogen-activated protein kinase (p38 MAPK) in host cells, CEP was effective indirectly inhibiting phosphorylation levels of the targets in PI3K/Akt and p38 MAPK signaling pathways. Moreover, CEP markedly decreased G₀/G₁ phase and increased G₂/M phase cells and decreased the expression of cyclin-dependent kinase1 (CDK1) and cyclinB1 in a dose-dependent manner. Additionally, CEP increased apoptosis in infected cells, reduced B cell lymphoma-2 (Bcl-2) protein levels, and increased the protein levels of Bcl-associated X protein (Bax), cleaved-caspase3, and nuclear IκB kinaseα (IκBα). Collectively, CEP could arrest the cell cycle in the G₂/M phase and induce apoptosis in infected cells by inhibiting the PI3K/Akt and p38 MAPK signaling pathways, hence further reducing HSV-1 infection and subsequent reproduction.

Long non-coding RNA BX357664 inhibits gastric cancer progression by sponging miR-183a-3p to regulate the PTEN expression and PI3K/AKT pathway

Lately, long non-coding RNA (lncRNA) is recognized as a key regulator of gastric cancer (GC) which has aroused great interest in the fields of medicine, toxicology, and functional food. Studies related to LncRNA expression microarray data indicate that BX357664 is down-regulated in GC specimens. However, the expression pattern and molecular mechanism of BX357664 in GC have not been studied so far. The purpose of this study was to investigate the expression of lncRNA BX357664 in GC and its function in GC cell lines. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the level of BX357664 in 50 pairs of cancer tissues and adjacent non-cancer tissues collected from GC patients. It was found that BX357664 level was lowered in cancer specimens than adjacent non-cancer tissues and correlated with tumor size and TNM stage. Also, we used cell counting kit 8 (CCK8), cell clone formation assay and transwell assay, which affirmed that up-regulation of BX357664 inhibited the proliferation, migration, and invasion of GC cells, but promoted apoptosis. In the dual-luciferase report analysis, BX357664 acted as a miR-183-3p ceRNA to target and regulate the expression of PTEN and affect the PI3K/AKT pathway. These results indicate that BX357664 can inhibit the proliferation and metastasis of GC through the miR-183-3p/PTEN/PI3K/AKT pathway, which may serve as potential targets for the treatment of GC in the future.

Anti-triple-negative breast cancer metastasis efficacy and molecular mechanism of the STING agonist for innate immune pathway

BACKGROUND

With high recurrence and metastatic rates, triple-negative breast cancer (TNBC) has few therapy choices. The innate immune stimulator of interferon genes protein (STING) pathway has emerged as a critical foundation for improving anticancer immunotherapy. Although 2',3'-cGAMP has been shown to have therapeutic potential as a STING agonist in subcutaneous solid tumour treatments in mice, the effect of cGAMP in metastatic malignancies has received less attention.

METHODS

Bioluminescence imaging technology was applied to monitor TNBC tumour cell metastasis in living mice. Serum biochemical test and blood routine examination of mice were used to demonstrate cGAMP administration had no toxicity. The activation of DCs and CD8+ T cells was demonstrated by flow cytometry. The pharmacological mechanism of cGAMP for suppressing breast tumour metastasis was also explored.

RESULTS

cGAMP treatment substantially suppressed tumour development and metastasis without adverse effects. cGAMP activated the cGAS-STING-IRF3 pathway, which modified the tumour immune milieu to reverse the Epithelial-Mesenchymal Transition (EMT) and PI3K/AKT pathways and prevent tumour metastasis. It was postulated and proven that cGAMP had a pharmacological mechanism for reducing breast tumour metastasis.

CONCLUSION

The findings suggest that cGAMP could be useful in the immunotherapy of immune-insensitive metastatic breast cancer.

KLF2 reduces dexamethasone-induced injury to growth plate chondrocytes by inhibiting the Runx2-mediated PI3K/AKT and ERK signalling pathways

Dexamethasone (Dex) is a type of glucocorticoid drug. Long term use can induce growth plate chondrocytes (GPCs) apoptosis, impair differentiation, and inhibit cell proliferation and bone growth. It has been reported that Krüppel-like factor 2 (KLF2) inhibits osteoblast damage induced by Dex, but the role in Dex-induced GPCs remains unclear. Dex was used to construct a model of growth plate injury in vitro. CCK-8 and TUNEL kits were used to determine cell viability and apoptosis. A model of growth plate injury was established by intraperitoneal injection of Dex. Immunohistochemistry was used to investigate the expression of KLF2 in rats. The results showed that KLF2 expression of rat tibial GPCs was down-regulated after Dex stimulation. Overexpression of KLF2 promoted cell viability and cell cycle, while inhibited apoptosis of growth plate Dex-induced chondrocytes. Moreover, KLF2 inhibited Runx2-mediated PI3K/AKT and ERK signalling pathways. And PI3K/AKT and ERK signalling pathways, which were involved in the regulation of KLF2 on GPCs. Further studies showed that KLF2 alleviated growth plate injury in vivo. In conclusion, our study found that KLF2 promoted proliferation and inhibited apoptosis of Dex-induced GPCs by targeting the Runx2-mediated PI3K/AKT and ERK signalling pathways.