MEG3 Induces Cervical Carcinoma Cells' Apoptosis Through Endoplasmic Reticulum Stress by miR-7-5p/STC1 Axis.

Background: Many patients with advanced cervical cancer (CC) have a poor prognosis and their mortality rank the first among women with malignant tumors. It's essential to explore the molecular mechanism of CC in clinical practice. Long noncoding RNA maternally expressed gene 3 (MEG3) has been reported to downregulate in CC tissues. However, the underlying mechanism of MEG3 in CC remains poorly elaborated. The current study aimed to explore the potential mechanism of MEG3 inducing endoplasmic reticulum stress (ERs)-mediated apoptosis of CC cells. Methods: The expression of MEG3 and miR-7-5p in CC tissues and cell lines was verified by quantitative reverse transcription/polymerase chain reaction (qRT-PCR). The vector of MEG3, miR-7-5p inhibitor, and sh-SCT1 were transfected into CC cell lines, and their expression was tested by qRT-PCR. Flow cytometry was used to detect apoptosis, and ERs-related protein expression was performed by Western blot. The regulatory relationship between MEG3/SCT1 and miR-7-5p was validated by Dual luciferase reporter assay. Results: CC tissues and cell lines showed downregulated MEG3 and STC1, and upregulated miR-7-5p. Overexpression of MEG3 or miR-7-5p inhibition induced ERs-triggered apoptosis of CC cells. In addition, sh-STC1 can reverse the effects of overexpressing MEG3 on CC cell apoptosis. In addition, dual luciferase reporter assay revealed that miR-7-5p can directly target to MEG3 and STC1. Conclusion: MEG3, act as a competing endogenous RNA of miR-7-5p, accelerates ERs-mediated apoptosis of CC cells through regulating SCT1 expression.

Trichostatin A Induces Autophagy in Cervical Cancer Cells by Regulating the PRMT5-STC1-TRPV6-JNK Pathway.

OBJECTIVE: The aim of this study was to investigate the effects of trichostatin A (TSA) on cervical cancer and the related mechanisms. METHODS: The HeLa and Caski cervical cancer cell lines were treated with different concentrations of TSA. Cell viability was measured by MTT assays. Cell apoptosis was analysed using flow cytometry. Expression of transient receptor potential cation channel, subfamily V, member 6 (TRPV6), protein arginine methyltransferase 5 (PRMT5), and stanniocalcin 1 (STC1) was determined by qRT-PCR and Western blotting. Protein levels of LC3 II/I, beclin1, p62, JNK, and p-JNK were detected by Western blotting. RESULTS: Treatment with TSA significantly decreased HeLa and Caski cell viability and enhanced the apoptosis rate in a dose-dependent manner. TSA markedly elevated beclin1 protein levels and the LC3 II/I ratio and significantly reduced p62 levels in a dose-dependent manner. In addition, TSA (1 µM) significantly suppressed PRMT5 and TRPV6 levels and enhanced STC1 and p-JNK levels. The lysosomal inhibitor bafilomycin-A1 synergistically enhanced the TSA-mediated increase in autophagic flux. Either the overexpression of TRPV6 or the inhibition of JNK signalling markedly enhanced cell viability, inhibited apoptosis, and autophagy and reduced p-JNK levels in TSA-treated cells. The inhibition of STC1 significantly increased TRPV6 protein levels and reduced p-JNK levels. Overexpression of PRMT5 dramatically decreased STC1 and p-JNK protein levels and increased TRPV6 levels. CONCLUSION: TSA suppresses cervical cancer cell proliferation and induces apoptosis and autophagy through regulation of the PRMT5/STC1/TRPV6/JNK axis.

miR-19 Promotes Cell Proliferation, Invasion, Migration, and EMT by Inhibiting SPRED2-mediated Autophagy in Osteosarcoma Cells.

Osteosarcoma is an aggressive malignancy with rapid development and poor prognosis. microRNA-19 (miR-19) plays an important role in several biological processes. Sprouty-related EVH1 domain protein 2 (SPRED2) is a suppressor of extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) signaling to inhibit tumor development and progression by promoting autophagy. In this study, we investigated the roles of miR-19, SPRED2, and autophagy in osteosarcoma. We detected the expression of miR-19, SPRED2, epithelial-mesenchymal transition (EMT) markers, and autophagy-related proteins via quantitative real-time polymerase chain reaction or western blot. To evaluate the function of miR-19 and SPRED2, we used MTT and colony formation assays to detect cell proliferation, Transwell, and wound-healing assays to detect cell invasion and migration. Targetscan and luciferase reporter assays confirmed the relationship between SPRED2 and miR-19. The expression of miR-19 was significantly upregulated in osteosarcoma, while SPRED2 was downregulated. miR-19 inhibitor reduced cell proliferation, invasion, migration, and EMT, while its cell biological effects were partially reversed by addition of autophagy inhibitor 3-methyladenine (3-MA) or SPRED2 siRNA in osteosarcoma. SPRED2, a suppressor of ERK/MAPK pathway that is known to trigger autophagy, was identified as a direct target of miR-19. SPRED2 overexpression increased cell proliferation, invasion, migration, and EMT by promoting autophagy, and the effects could be inhibited by 3-MA. Collectively, these findings reveal an underlying mechanism for development of osteosarcoma. miR-19 was upregulated in osteosarcoma cells, and negatively regulated SPRED2, thus promoting the malignant transformation of osteosarcoma cells via inhibiting SPRED2-induced autophagy. Therefore, miR-19/SPRED2 may be a potential target for the treatment of osteosarcoma.

Polydatin promotes the osteogenic differentiation of human bone mesenchymal stem cells by activating the BMP2-Wnt/ß-catenin signaling pathway.

Steroid-induced osteonecrosis of the femoral head (SONFH) is a refractory disease induced by glucocorticoids. Marrow mesenchymal stem cells (MSCs) differentiate into multiple bone matrix cells and have been used as cell-based therapies to treat ONFH. However, the osteogenesis of MSCs isolated from patients with SONFH is significantly decreased. Polydatin has been widely used in traditional Chinese remedies due to its multiple pharmacological actions. As shown in our previous study, Polydatin protects from oxidative stress and promotes BMSC migration. However, little is known about its role in BMSC (Bone marrow mesenchymal stem cells) osteogenesis; therefore, we further investigated the effect and mechanism of Polydatin in hBMSC osteogenesis. The ability of Polydatin to promote the proliferation and osteogenic differentiation of hBMSCs was determined using the MTT assay, ALP staining and the ALP activity assay. Next, qPCR and western blotting were performed to measure the levels of genes and proteins related to the osteogenesis of hBMSCs. Then, the effect of Polydatin on the nuclear translocation of ß-catenin was determined using immunofluorescence staining. Polydatin (30 µM) markedly enhanced the proliferation of hBMSCs and alkaline phosphatase (ALP) activity. Additionally, it also significantly upregulated the expression of osteogenic genes (Runx2, osteopontin, DLX5, osteocalcin, collagen type I and BMP2) and components of the Wnt signaling pathway (ß-catenin, Lef1, TCF7, c-jun, c-myc and cyclin D). These osteogenesis-potentiating effects of Polydatin were blocked by Noggin, an inhibitor of the BMP pathway, and DKK1, an inhibitor of the Wnt/ß-catenin pathway. However, DKK1 did not affect Polydatin-induced BMP2 expression. Based on our results, Polydatin promotes the proliferation and osteogenic differentiation of hBMSCs through the BMP2-Wnt/ß-catenin signaling pathway.

Long non-coding RNA TUG1 contributes to tumorigenesis of human osteosarcoma by sponging miR-9-5p and regulating POU2F1 expression.

Recent studies have shown that long non-coding RNAs (lncRNAs) have critical roles in tumorigenesis, including osteosarcoma. The lncRNA taurine-upregulated gene 1 (TUG1) was reported to be involved in the progression of osteosarcoma. Here, we investigated the role of TUG1 in osteosarcoma cells and the underlying mechanism. TUG1 expression was measured in osteosarcoma cell lines and human normal osteoblast cells by quantitative real-time PCR (qRT-PCR). The effects of TUG1 on osteosarcoma cells were studied by RNA interference in vitro and in vivo. The mechanism of competing endogenous RNA (ceRNA) was determined using bioinformatic analysis and luciferase assays. Our data showed that TUG1 knockdown inhibited cell proliferation and colony formation, and induced G0/G1 cell cycle arrest and apoptosis in vitro, and suppressed tumor growth in vivo. Besides, we found that TUG1 acted as an endogenous sponge to directly bind to miR-9-5p and downregulated miR-9-5p expression. Moreover, TUG1 overturned the effect of miR-9-5p on the proliferation, colony formation, cell cycle arrest, and apoptosis in osteosarcoma cells, which involved the derepression of POU class 2 homeobox 1 (POU2F1) expression. In conclusion, our study elucidated a novel TUG1/miR-9-5p/POU2F1 pathway, in which TUG1 acted as a ceRNA by sponging miR-9-5p, leading to downregulation of POU2F1 and facilitating the tumorigenesis of osteosarcoma. These findings may contribute to the lncRNA-targeted therapy for human osteosarcoma.

[Biomechanical evaluation of nickel-titanium shape-memory alloy enclosed interlocking intramedular nail].

OBJECTIVE: To study the biomechanical characteristics of Ni-Ti shape-memory alloy-enclosed interlocking intramedular nail Ni-Ti En for clinical application. METHODS: Six transverse fractures were induced in 6 fresh humeral shafts and fixed with Ni-Ti En, plate, interlocking intramedullary nail, and Ender nail, respectively. The specimens then underwent stress analysis for comparison of the bending strength, twisting force, and flexibility. RESULTS: The bending strength of Ni-Ti En was not significantly different from that of the plate and better than ender's nail; the twisting force of the interlocking intramedullary nail was comparable with the plate, but better than Ender nail. CONCLUSION: Ni-Ti Enpossess good biomechanical property to meet the demand of osteosynthesis, and its less stress protection, freedom of distant nail locking, flexibility and stable fixation may accelerate fracture healing.