Calycosin, a Phytoestrogen Isoflavone, Induces Apoptosis of Estrogen Receptor-Positive MG-63 Osteosarcoma Cells via the Phosphatidylinositol 3-Kinase (PI3K)/AKT/Mammalian Target of Rapamycin (mTOR) Pathway.

BACKGROUND Osteosarcoma is the most common primary bone malignancy and often presents at an early age. Calycosin is a phytoestrogen isoflavone, which has previously been reported to inhibit tumor cell growth. The aim of this study was to investigate the effects of calycosin on apoptosis of estrogen receptor (ER)-positive and ER-negative human osteosarcoma cell lines and tumor xenografts in mice. MATERIAL AND METHODS Cultured ER-positive MG-63 human osteosarcoma cells and ER-negative U2-OS human osteosarcoma cells were treated with increasing doses of calycosin (0, 25, 50, and 100 µm). Cell viability and apoptosis were studied by an MTT assay and flow cytometry. Western blot measured the expression levels of the apoptosis-related protein p-PI3K, p-Akt, and p-mTOR in MG-63 cells, with and without pretreatment with the PI3K inhibitor, LY294002, the AKT inhibitor, MK-2206, or the mTOR inhibitor, rapamycin. MG-63 tumor-bearing nude mice were used to evaluate the effects of treatment with calycosin. RESULTS Calycosin treatment inhibited proliferation and induced apoptosis in MG-63 cells, but had no effect on U2-0S cells. In MG-63 cells, calycosin treatment increased the expression of the PI3K/AKT/mTOR pathway proteins; inhibitor assays showed that expression of the PI3K protein was most strongly associated with the antitumor effects of calycosin. In the nude mouse MG-63 tumor xenografts, calycosin inhibited tumor growth and regulated the expression levels of apoptosis-related PI3K/AKT/mTOR pathway proteins. CONCLUSIONS The phytoestrogen, calycosin, induced apoptosis of cells of the ER-positive osteosarcoma cell line, MG-63, via the PI3K/AKT/mTOR pathway, with these effects being mainly due to PI3K.

A1BG-AS1 promotes the biological functions of osteosarcoma cells via regulating the microRNA-148a-3p/USP22 axis and stabilizing the expression of SIRT1 through deubiquitinase function.

BACKGROUND: The study aims to explore the role of A1BG antisense RNA 1 (A1BG-AS1), microRNA (miR)-148a-3p and ubiquitin-specific protease 22 (USP22) on osteosarcoma (OS) cell growth. RESEARCH DESIGN & METHODS: A1BG-AS1, miR-148a-3p, USP22, and silent information regulator 2 homolog 1 (SIRT1) levels in OS tissues and cells were determined. The effects of A1BG-AS1, miR-148a-3p, and USP22 on the biological functions of OS cells were examined by functional assays. In vivo assay was conducted to observe the effect of A1BG-AS1 on OS growth in vitro. The relationship of A1BG-AS1, miR-148a-3p, and USP22 was analyzed by bioinformatics analysis, RNA-fluorescence in situ hybridization, luciferase activity, and RNA binding protein immunoprecipitation assays. The relation between USP22 and SIRT1 was evaluated by immunoprecipitation. RESULTS: A1BG-AS1 and USP22 were highly expressed, and miR-148a-3p was lowly expressed in OS tissues and cells. Down-regulation of A1BG-AS1 and USP22 or up-regulation of miR-148a-3p impaired the malignant behaviors of OS cells. A1BG-AS1 sponged miR-148a-3p, and miR-148a-3p targeted USP22, thereby inhibiting USP22 expression. Up-regulating USP22 reversed the A1BG-AS1 suppression-induced phenotypic inhibition of OS cells. USP22 affected the biological functions of OS cells by deubiquitinating SIRT1. CONCLUSION: A1BG-AS1 facilitates the biological functions of OS cells via mediating the miR-148a-3p/USP22 axis.

Quercetin suppresses inflammatory cytokine production in rheumatoid arthritis fibroblast-like synoviocytes.

Rheumatoid arthritis (RA) is a chronic, progressive and systemic autoimmune disease mainly characterized by symmetric multijoint synovitis. Quercetin has anti-inflammatory, anti-oxidation and immune regulation activities, and therefore shows high medicinal value. The present study aimed to observe the effect of quercetin on fibroblast-like synoviocytes (FLSs) in RA. Rheumatoid arthritis fibroblast-like synoviocytes (RAFLSs) were pretreated with 50 nmol/l quercetin for 2 h and were then stimulated using TNF-α for 24 h for subsequent experiments. RAFLSs were transfected with short interfering (si)-X-inactive specific transcript (XIST), microRNA (miR)-485 mimic, miR-485 inhibitor or si-PSMB8 or combination. ELISA, PCR and western blotting was used to evaluate the effect of quercetin on RAFLSs treated with TNF-α. It was revealed that quercetin inhibited the production of inflammatory cytokines and the expression of XIST in RAFLSs induced by TNF-α. Bioinformatics analysis indicated that XIST acted as a sponge for miR-485 and that proteasome subunit ß type-8 (PSMB8) was a direct target of miR-485. Moreover, PSMB8 functioned as a suppressor in inflammatory cytokine production of RAFLSs induced by TNF-α. Overall, quercetin was observed to inhibit the production of inflammatory cytokines and the expression of XIST in RAFLSs induced by TNF-α. Moreover, XIST-silencing could suppress the inflammatory reaction by sponging miR-485 in cells treated with TNF-α. Altogether, quercetin could suppress the development of RA in vitro.

Role of Nectin­4 protein in cancer (Review).

The Nectin cell adhesion molecule (Nectin) family members are Ca2+­independent immunoglobulin­like cellular adhesion molecules (including Nectins 1­4), involved in cell adhesion via homophilic/heterophilic interplay. In addition, the Nectin family plays a significant role in enhancing cellular viability and movement ability. In contrast to enrichment of Nectins 1­3 in normal tissues, Nectin­4 is particularly overexpressed in a number of tumor types, including breast, lung, urothelial, colorectal, pancreatic and ovarian cancer. Moreover, the upregulation of Nectin­4 is an independent biomarker for overall survival in numerous cancer types. A large number of studies have revealed that high expression of Nectin­4 is closely related to tumor occurrence and development in various cancer types, but the manner in which Nectin­4 protein contributes to the onset and development of these malignancies is yet unknown. The present review summarizes the molecular mechanisms and functions of Nectin­4 protein in the biological processes and current advances with regard to its expression and regulation in various cancer types.

NFKB1 common variants and PPP1R13L and CD3EAP in relation to lung cancer risk in a Chinese population.

Genetic variations in NFKB1 have been associated with cancer risk. This investigation intended to evaluate the possible association between common variants in NFKB1 and lung cancer risk and gene-gene and gene-environment interactions. A study containing 384 Chinese lung cancer cases and 387 cancer-free controls was conducted. 5 htSNPs (rs3774934, rs13117745, rs230541, rs1801, rs3774965) in NFKB1 and interaction with common variants in NFKB1 and PPP1R13L and CD3EAP and smoking-duration were assessed. No association with lung cancer risk was detected for individual htSNP in four genetic models, but the haplotype consisting of the wild-type alleles of rs3774934(G), rs13117745(C), rs230541(A), and rs1801(G) was associated with lowered lung cancer risk after adjustment for smoking duration [OR (95% CI) = 0.71 (0.51-0.98), P = 0.036]. There was no interaction between NFKB1 polymorphisms and PPP1R13L and CD3EAP and smoking status in relation to lung cancer risk. Two significant models: smoking duration as main effect (P < 0.0010) and smoking duration-PPP1R13L rs1970764 combination (P = 0.0040-0.0050) were tested. The results suggest that NFKB1 common variants and smoking duration and smoking duration-PPP1R13L rs1970764 interaction could be concerned with the lung cancer development in a Chinese population. The present findings add to the evidence implicating inflammation in lung cancer etiology.