Tumor cells inhibit the activation of ILC2s through up-regulating PD-1 expression.

OBJECTIVE: Up-regulating programmed cell death ligand-1(PD-L1) expressed on tumor cells and tumor-infiltrating myeloid cells interacting with up-regulated programmed cell death-1 (PD-1) expressed on tumor-infiltrating lymphoid cells greatly hinder their tumor-inhibiting effect. It is necessary to explore the deep mechanism of this negative effect, so as to find the potential methods to improve the immunotherapy efficiency. METHODS AND RESULTS: In this study, we found that the PD-1 expression in lung cancer-infiltrating type II innate lymphoid cells (ILC2s) was highly up-regulated, which greatly restrained the activation and function of ILC2s. Furthermore, anti-PD-1 could restore the inhibition and effective cytokine secretion of ILC2s when co-cultured with tumor cells. In vivo studies proved that anti-PD-1 treatment promoted the activation of tumor-infiltrating ILC2s and inhibited the tumor growth of LLC-bearing nude mice. DISCUSSION: Our studies demonstrate a new PD-1/PD-L1 axis regulating mechanism on innate immune cells, which provide a useful direction to ILC2s-based immunotherapy to cancer diseases.

Circular RNA circAFF2 accelerates gastric cancer development by activating miR-6894-5p and regulating ANTXR 1 expression.

BACKGROUND: Circular RNAs (circRNAs) contain a new class of non-coding RNAs that play an important role in adjusting biological function and gene expression. But the function of circRNAs in gastric cancer remains unclear. In the present research, we explored the functions of circular RNA AFF2(circAFF2, hsa_circ_0001947) in gastric cancer cells and an animal model of gastric cancer. METHODS: The expression of circAFF2, microRNA-6894-5p (miR-6894-5p), and Anthrax toxin receptor 1 (ANTXR 1) were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cell counting kit 8 (CCK-8) and transwell assays were used to analyze the knockdown effects of circAFF2, miR-6894-5p, and overexpression of ANTXR 1 on cell proliferation, migration, and invasion abilities. Binding interactions between, circAFF2 and miR-6894-5p and between, miR-6894-5p and ANTXR 1 were detected by Dual-luciferase reporter assays. Levels of protein expression were analyzed by Western blotting. Tumor models were established by subcutaneous injection of tumor cells in nude mice. RESULT: The result showed that circAFF2 expression was significantly increased in gastric cancer cell lines and tissues. The knockdown of circAFF2 dramatically suppressed the cell migration, invasion and proliferation of gastric cancer cells. In vivo studies showed that knockdown of circAFF2 delayed tumor growth. Furthermore, we revealed that circAFF2 functioned as a sponge to absorb miR-6984-5p and elevated the expression of ANTXR 1. CONCLUSION: CircAFF2 acts as an oncogene in gastric cancer and exerts its effects via miR-6894-5p/ANTXR 1 signaling.

Proanthocyanidin promotes functional recovery of spinal cord injury via inhibiting ferroptosis.

Improving the microenvironment of lesioned spinal cord to minimize the secondary injury is one important strategy to treat spinal cord injury (SCI). The ensuing hemorrhage after SCI has tight connection with ferroptosis. This study investigated the effects of proanthocyanidins (PACs) on SCI repair and the underlying mechanisms. Adult female mice were divided into four groups, including sham, SCI, PACs5 and PACs10 (i.p. 5 and 10 mg/kg PACs after SCI respectively). The impacts of SCI and PACs treatment on redox parameters (iron contents, TBARS, GSH, and GPX activities) and ferroptosis essential factors such as ACSL4, LPCAT3, Alox15B, Nrf2, HO-1, GPX4 were investigated. The results demonstrated that PACs treatment significantly decreased the levels of iron, TBARS, ACSL4, and Alox15B, while increased the levels of GSH, GPX4, Nrf2, and HO-1 in traumatic spinal cords. Above all, PACs improved the locomotive function of SCI mice. These results suggest that PACs might be potential therapeutics for SCI repair by inhibiting ferroptosis in SCI.

Migration of gastric cancer is suppressed by recombinant Newcastle disease virus (rL-RVG) via regulating α7-nicotinic acetylcholine receptors/ERK- EMT.

BACKGROUND: Nicotinic acetylcholine receptors (nAChRs) have been reported to be overexpressed in malignancies in humans and is associated with tumorigenesis and cell migration. In previous studies of gastric cancer, alpha7 nicotinic acetylcholine receptor (α7-nAChR) overexpression leads to epithelial-mesenchymal transition (EMT) and promotes the migration of gastric cancer cells. Recombinant avirulent LaSota strain of Newcastle disease virus (NDV) expressing the rabies virus glycoprotein (rL-RVG) may promote apoptosis of gastric cancer cells and reduces the migration of lung cancer metastasis. However, whether rL-RVG inhibits migration of gastric cancer cells and what the underlying functional mechanism is remains unknown. METHODS: The gastric cancer cell lines BGC and SGC were randomly divided into 3 groups: rL-RVG, NDV and Phosphate Buffered Solution (PBS) control groups. Furthermore,we adopted ACB and MLA,α7nAChR-siRNA for the overexpression and silencing of α7-nAChR.Corynoxenine was used for inhibiting the MEK-ERK pathway. Western blot, Immunofluoresce,cell proliferation assays,cell migration analyses through wound-healing assays and Transwell assays were used to explore the underlying mechanisms. A mouse xenograft model was used to investigate the effects of rL-RVG,NDV on tumor growth. RESULTS: In this study, our findings demonstrate that rL-RVG suppressed the migration of gastric cancer cells and reduced EMT via α7-nAChR in vitro. Furthermore rL-RVG decreased the phosphorylation levels of the MEK/ERK signaling pathway such as down-regulating the expression of P-MEK and P-ERK. Additionally, rL-RVG also reduced the expression level of mesenchymal markers N-cadherin and Vimentin and enhanced the expression of the epithelial marker E-cadherin. Lastly, rL-RVG inhibited nicotinic acetylcholine receptors (nAChRs) to suppress cell migration and epithelial to mesenchymal transition (EMT) in gastric cell. We also found that rL-RVG suppresses the growth of gastric cancer subcutaneous tumor cells in vivo. CONCLUSION: rL-RVG inhibits α7-nAChR-MEK/ERK-EMT to suppress migration of gastric cancer cells.

LaSota Strain Expressing The Rabies Virus Glycoprotein (rL-RVG) Suppresses Gastric Cancer by Inhibiting the Alpha 7 Nicotinic Acetylcholine Receptor (α7 nAChR)/Phosphoinositide 3-Kinase (PI3K)/AKT Pathway.

BACKGROUND The recombinant avirulent Newcastle disease virus (NDV) LaSota strain expressing the rabies virus glycoprotein (rL-RVG) can induce much greater apoptosis than can NDV in gastric carcinoma cells, but the mechanisms involved remains unclear. MATERIAL AND METHODS The 2 gastric carcinoma cell lines were divided into the rL-RVG group, the NDV group, and the PBS group. MTT assay was used to detect and analyze cell viability. siRNA for alpha7-nAChR, alpha7-nAChR antagonist, or alpha7-nAChR agonist, AKT antagonist, and p-AKT agonist were used for pretreatment. The protein expressions of RVG, NDV, alpha7-nAChR, cleaved caspase-3, p-AKT, PI3K, Bcl-2, and Bax proteins were detected by Western blot assay. Immunofluorescence was used to detect expressions of alpha7-nAChR proteins. Light microscopy, flow cytometry, and TUNEL assay were used to assess apoptosis. RESULTS The results showed that 2 virus concentrations over 10³ dilution caused greater cell proliferation inhibition. rL-RVG treatment increased the expression of alpha7-nAChR, cleaved caspase-3, and Bax protein but decreased the expression of p-AKT, PI3K, and Bcl-2 protein. When the groups were pretreated with alpha7-nAChR antagonist, the alpha7-nAChR, cleaved caspase-3, and Bax protein expression increased, but the expression of p-AKT, PI3K, and Bcl-2 protein was clearly decreased. However, the results in the alpha7-nAChR agonist group were the opposite. When treated with the AKT antagonist, the result was the same as in the rL-RVG treatment group. The result in the AKT agonist group was the opposite of that in the AKT antagonist group. Compared with the NDV group, the results of light microscopy, FCM, and TUNEL assay showed that alpha7-nAChR antagonist significantly affected the apoptosis of gastric cancer cells in the rL-RVG group. CONCLUSIONS rL-RVG leads to much greater apoptosis through the alpha7-nAChR/PI3K/AKT pathway.