Reticulocalbin-1 knockdown increases the sensitivity of cells to Adriamycin in nasopharyngeal carcinoma and promotes endoplasmic reticulum stress-induced cell apoptosis.

Nasopharyngeal carcinoma (NPC) mainly appears in southeastern Asian countries, including China. Adriamycin (ADM), a type of antitumor drug, is widely applied in treatments against various cancers. Nevertheless, cancer cells will eventually develop drug resistance to ADM. The present study aims to explore the potential role of reticulocalbin-1 (RCN1) in NPC cells resistance to ADM. Microarray-based analysis was used to screen NPC-related genes, with RCN1 acquired for this current study. RCN1 expression in NPC tissues and cells was determined. The biological function of RCN1 on NPC cell apoptosis was evaluated via gain- and loss-of-function experiments in 5-8 F/ADM and 5-8 F cells by delivering si-RCN1 and RCN1-vector. The function of endoplasmic reticulum (ER) stress on cell apoptosis was measured with the involvement of the PERK-CHOP signaling pathway. Furthermore, tumor formation in nude mice was performed to evaluate the survival condition and RCN1 effects in vivo. RCN1 was highly expressed in NPC tissues and cell lines. The increased expression of ER-related proteins ATF4, CHOP, and the extents of IRE1 and PERK phosphorylation were observed. RCN1 knockdown was found to reduce resistance of NPC cells/tissues to ADM while activating ER stress through the activated PERK-CHOP signaling pathway, which further promoted NPC cell apoptosis. These in vitro findings were detected in vivo on tumor formation in nude mice. In conclusion, the present study provides evidence that RCN1 knockdown stimulates ADM sensitivity in NPC by promoting ER stress-induced cell apoptosis, highlighting a theoretical basis for NPC treatment.

The allogeneic umbilical cord mesenchymal stem cells regulate the function of T helper 17 cells from patients with rheumatoid arthritis in an in vitro co-culture system.

BACKGROUND: Previous in vivo studies have shown that mesenchymal stem cell (MSC) transplantation significantly improves the condition of a number of autoimmune diseases including autoimmune cerebrospinal meningitis, multiple sclerosis, glomerulonephritis and systemic lupus erythematosus. METHODS: To investigate the immunoregulatory effect of stem cell transplantation, human umbilical cord MSCs were co-cultured with peripheral blood mononuclear cells (PBMCs) from patients with rheumatoid arthritis (RA). Orphan nuclear receptor gamma (ROR-γ) mRNA and protein expression was detected with real-time PCR and Western blotting. Interleukin (IL)-17, IL-6 and tumor necrosis factor (TNF-α) in the cell culture supernatant were measured using a flow cytometric bead capture method. RESULTS: After 72 hours of co-culture, the mRNA and protein expression levels of ROR-γ in co-cultured PBMCs were decreased compared with that in PBMC of RA patients cultured alone (p < 0.05). Moreover, the decrement was positively related to the disease activity of RA (p < 0.05). Decreased secretion of IL-17, TNF-α and IL-6 were also found in co-culture supernatants of PBMCs from patients with severe and moderate disease activity, but not in supernatant from PBMCs cultured alone. The decreased cytokine expression levels were positively correlated to the concentrations of MSCs. In contrast, PBMCs from healthy controls or patients with mild RA did not show significant differences in ROR-γ expression or cytokine secretion following co-culture with MSCs as compared with those cultured alone. CONCLUSIONS: In vitro co-culture with MSCs down-regulated the inflammatory response of PBMCs from RA patients with severe disease activity, but had no significant effect on PBMCs from healthy controls or patients with mild disease activity, suggesting that the immunoregulatory role of MSCs may associate with the occurrence of inflammatory mediators.

Comprehensive evaluation of different T-helper cell subsets differentiation and function in rheumatoid arthritis.

Rheumatoid arthritis (RA) is the most common autoimmune disorder. Loss of Th1/Th2 and Th17/Treg balance has been reported in several inflammatory autoimmune diseases. This study was to investigate Th1, Th2, Th17, and Treg differentiation and related cytokines in RA patients. The frequencies of Th1, Th2, Th17, and Treg cells in peripheral blood of RA patients (n = 76) and healthy controls (n = 18) were determined by flow cytometry. Eight serum cytokines were analyzed using cytometric bead array. The results demonstrated that RA patients exhibited increased peripheral Th1/Th17 cells and Th1/Th17-related cytokines. However, Th1 cells only reached significant difference at advanced stage, but Th17 at all stages, suggesting more important roles in Th17 cells. For Th2 and Treg cells, there was a different function pattern in RA progression. Although with the increase of DAS28 score, Th2 cell experienced some degree of decrease in RA patients, no significant difference was observed. IL-4 and IL-10 showed a significant increase in RA patients. These indicated that Th2 cells might exert immunosuppression effects mainly by secreting cytokines. Treg cells were found significantly decreased in RA patients, but no difference was observed in TGF-ß expression, indicating a cell-cell interaction pattern in Treg cell.