La-related protein 1 (LARP1) is a conserved RNA-binding protein and is known to regulate 5'-terminal oligopyrimidine tract (TOP) mRNA translation. Dysregulated LARP1 has been reported to be related to the development of several cancers. However, the exact function and mechanism of LARP1 in non-small cell lung cancer (NSCLC) is largely unknown. In the present study, we found that the mRNA levels of LARP1 were increased in NSCLC cells compared to those in normal control cells. Knockdown of LARP1 inhibited cell proliferation, migration and invasion in NSCLC cells and tumourigenicity in H520 cells. Both in vitro and in vivo analyses confirmed that STAT3 signalling was inactivated by the knockdown of LARP1. Moreover, LARP1 was identified as a direct target of miR-374a. Overexpression of miR-374a attenuated the promotor effects of LARP1 by inhibiting proliferation, metastasis and STAT3 signalling. Clinically, LARP1 was markedly overexpressed in NSCLC tissues, and upregulated LARP1 was correlated with tumour progression and poor survival. The expression of miR-374a was negatively correlated with the expression of LARP1 in NSCLC tissues. Furthermore, we found that XIST functioned as a competing endogenous RNA to suppress miR-374a, which regulated its downstream target LARP1. In summary, we suggest that the dysfunction of the XIST/miR-374a/LARP1 axis contributes to NSCLC and may serve as a promising therapeutic strategy for treatment.
SummaryAutophagy can mediate antiviral immunity. However, it remains unknown whether autophagy regulates the immune response of dendritic cells (DCs) to influenza A (H1N1) pdm09 infection. In this study, we found that infection with the H1N1 virus induced DC autophagy in an endocytosis-dependent manner. Compared with autophagy-deficient Beclin-1 +/À mice, we found that bone-marrow-derived DCs from wild-type mice (WT BMDCs) presented a more mature phenotype on H1N1 infection. Wildtype BMDCs secreted higher levels of interleukin-6 (IL-6), tumour necrosis factor-a ( Our data indicate that autophagy is important in the regulation of the DC immune response to H1N1 infection, thereby extending our understanding of host immune responses to the virus.
Lung carcinoma is the leading cause of mortality due to cancer worldwide. Autophagy has a significant role in the development and progression of non‑small cell lung carcinoma (NSCLC). A previous study has revealed that tetrahydrocurcumin (THC), a traditional Chinese medicine isolated from Curcuma wenyujin (Chen & Ling, 1981), induces autophagy in human A549 NSCLC cells. The present study evaluated THC‑induced autophagy in A549 cells using various assays, including the Cell Counting Kit‑8, acridine orange staining, flow cytometry, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR), and western blot analysis of the markers of autophagy. THC inhibited the growth and proliferation of A549 cells (P<0.05). Acridine orange staining and flow cytometry revealed that THC treatment significantly enhanced autophagic cell proliferation inhibition (P<0.05). The RT‑qPCR analysis revealed that THC treatment increased Beclin‑1 expression level and compared with the control group (P<0.05). The light chain 3 (LC3)‑II/LC3‑I ratio was reduced in THC‑treated cells when compared with the control group (P<0.05). Protein expression of various markers of autophagy, including p62, phosphorylated (p)‑mechanistic target of rapamycin (mTOR), phosphoinositide 3‑kinase (PI3K), p‑PI3K, protein kinase B (Akt), and p‑Akt was significantly reduced in THC‑treated cells (P<0.05). In conclusion, the present study revealed the underlying mechanisms associated with THC‑induced autophagy. A promising method of enhancing the therapeutic efficacy of THC against NSCLC cells may include inducing autophagy via inhibition of the PI3K/Akt/mTOR signaling pathway.
The aim of the present study was to assess the neuroprotective effects of tetrahydrocurcumin (THC) in a mouse model of cerebral ischemia/reperfusion (I/R) injury, and to investigate the involvement of Golgi reassembly and stacking protein 65 (GRASP65) and the extracellular signal‑regulated kinase (ERK) signaling pathway. Cerebral I/R injury was induced using the Pulsinelli four‑vessel occlusion method. After 5 min of reperfusion, mice received THC (5, 10 or 25 mg/kg) or saline by intraperitoneal injection. After 24 h of reperfusion, mice underwent neurological evaluation. Infarct volumes were determined by triphenyltetrazolium chloride staining, and levels of superoxide dismutase and malondialdehyde were measured in brain tissue homogenates. Expression of GRASP65, phosphorylated‑GRASP65, ERK and phosphorylated‑ERK was determined by western blotting. THC induced a dose‑dependent decrease in the phosphorylation of ERK and GRASP65. Thus, THC attenuated I/R injury‑induced activation of the ERK signaling pathway and reduced the phosphorylation of GRASP65. THC exhibited a dose‑dependent protective effect against cerebral I/R injury, mediated by suppression of the ERK signaling pathway and a subsequent reduction in GRASP65 phosphorylation. The current study provided new information in the research of the cerebral ischemia‑reperfusion injury mechanism.
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