ABSTRACT
BACKGROUND: Osteosarcoma (OS) is one of the most common bone tumors in adolescents and young adults. Emerging evidence suggested ncRNA (lncRNA and miRNA) are closely associated with cell progression, apoptosis and autophagy. However, the role of regulatory network between ncRNA and mRNA in OS has not been fully verified. METHODS: lncRNA XIST, miRNA expression were detected by qRT-PCR. The protein expression of LC3, p62, AKT, p-AKT, mTOR and p-mTOR was measured by western blot. MTT assay and flow cytometry were applied to measure cell proliferation and apoptosis. Luciferase assay was used to ensure the relationship between lncRNA, miRNA and mRNA. GFP-LC3 cells were observed using fluorescence microscope. RESULTS: XIST expression was up-regulated but miR-375-3p was down-regulated in OS tissues and cells. Luciferase assay results demonstrated that miR-375-3p was a target of XIST and mTOR was a target mRNA of miR-375-3p. In addition, knockdown of XIST and mTOR inhibited OS cell proliferation and autophagy, but induced apoptosis. Knockdown of XIST could reverse the effect of miR-375-3p inhibitor on OS cells. The effects of si-mTOR of OS cells could be reversed by silencing miR-375-3p. Moreover, knockdown of XIST inhibited AKT/mTOR signaling pathway via sponging miR-375-3p. CONCLUSION: Knockdown of XIST inhibited cell growth and autophagy but induced cell apoptosis by suppressing the AKT/mTOR signaling pathway by sponging miR-375-3p.
ABSTRACT
OBJECTIVES: To study the effect of aspirin on healing process of osteoporotic fracture (OPF) in rats. METHODS: A total of 50 female Wistar rats aged 3 months were randomly divided into observation group and control group, castration method was adopted to establish the osteoporosis (OP) model. After artificial preparing fractures on the midpoint of left femur, fixing gram needle intramedullary, OPF modeling was complete. Aspirin lavage of 33 mg once a day was adopted in observation group after modeling, same amount of normal saline was used in the control as placebo. From each group, selected 5 rats at the 2nd, 4th, 8th and 12th week after modeling to measure the bone mineral density (BMD) and histological examination of the fracture callus, radiology observation was conducted at the 8th and 12th week. Left femur biomechanical measurement was taken at the 12th week. RESULTS: BMD values of observation group at each time point were significantly higher than that of the control group after modeling (P<0.05); Histological observation showed that at the 8th week, the endochondral ossification process of observation group was faster than that of observation group, with fuzzy fracture line in observation group and clear fracture line in observation group; at the 12th week, fracture line disappeared in observation group, fracture line of the control group was fuzzy at the same time; three-point bending load of the left femur in observation group rats was significantly higher than that of control group after 12 weeks (P<0.05). CONCLUSIONS: Aspirin can accelerate the healing of new callus in OPF rats, increase bone density and biomechanics strength, and promote fracture healing of osteoporotic rats.
ABSTRACT
BACKGROUND AND AIMS: Whole-body vibration (WBV) presents as osteogenic in animal models and young patients, but the effect remains unclear in senior people. The use of alternative tilting during WBV to ameliorate bone mass and bone metabolism, particularly in senior people, has not previously been reported. This study assessed changes in bone mineral density (BMD) and bone metabolism in senior people after six-month treatment of whole-body vibration with alternative tilting (WBVAT). METHODS: Fifty-three senior people (11M/42F, >65 yrs, mean age 77) and 15 adults (4M/11F, 50-60 yrs, mean age 53) were enrolled and assigned randomly to WBVAT (senior: n=27; adult: n=7) and control groups (senior: n=26; adult: n=7), respectively. The WBVAT groups were subjected to vertical vibration (0.5-0.8 g, 45-55 Hz) and alternative tilting (2° tilting angle or 8 mm displacement at 0.4 Hz) 20 minutes per day, 3 days a week, for 6 months. BMD in the lumbar spine and femoral neck was measured at 0, 3 and 6 months, respectively, as well as biochemical markers of bone metabolism, including serum calcium, phosphorus, alkaline phosphatase (ALP), osteocalcin and tartrate resistance acid phosphatase at 0, 1, 3 and 6 months, respectively. RESULTS: After 6-month WBVAT treatment, BMD in the lumbar spine and femoral neck increased significantly by 2.52% and 3.22% for senior people, and 1.63% and 2.05% for adults, respectively. The 6-month WBVAT treatment increased BMD in the senior people, both with and without osteoporosis (OP) and in both men and women, but led to a BMD gain greater in people with OP (p<0.01) and women (p<0.01), respectively. The serum ALP level increased significantly by a net 24.4% in seniors after WBVAT treatment at 3 months; other biochemical markers showed non-significant differences between the WBVAT and control groups. CONCLUSIONS: WBVAT treatment may increase BMD in senior people, particularly those with OP and women. Changes in bone metabolism after WBVAT treatment were not observed in most cases.
