MicroRNAs are short regulatory RNAs that negatively modulate protein expression at a post-transcriptional and/or translational level and are deeply involved in the pathogenesis of several types of ...cancers. Specifically, microRNA-221 (miR-221) is overexpressed in many human cancers, wherein accumulating evidence indicates that it functions as an oncogene. However, the function of miR-221 in human osteosarcoma has not been totally elucidated. In the present study, the effects of miR-221 on osteosarcoma and the possible mechanism by which miR-221 affected the survival, apoptosis, and cisplatin resistance of osteosarcoma were investigated.
Real-time quantitative PCR analysis revealed miR-221 was significantly upregulated in osteosarcoma cell lines than in osteoblasts. Both human osteosarcoma cell lines SOSP-9607 and MG63 were transfected with miR-221 mimic or inhibitor to regulate miR-221 expression. The effects of miR-221 were then assessed by cell viability, cell cycle analysis, apoptosis assay, and cisplatin resistance assay. In both cells, upregulation of miR-221 induced cell survival and cisplatin resistance and reduced cell apoptosis. In addition, knockdown of miR-221 inhibited cell growth and cisplatin resistance and induced cell apoptosis. Potential target genes of miR-221 were predicted using bioinformatics. Moreover, luciferase reporter assay and western blot confirmed that PTEN was a direct target of miR-221. Furthermore, introduction of PTEN cDNA lacking 3'-UTR or PI3K inhibitor LY294002 abrogated miR-221-induced cisplatin resistance. Finally, both miR-221 and PTEN expression levels in osteosarcoma samples were examined by using real-time quantitative PCR and immunohistochemistry. High miR-221 expression level and inverse correlation between miR-221 and PTEN levels were revealed in osteosarcoma tissues.
These results for the first time demonstrate that upregulation of miR-221 induces the malignant phenotype of human osteosarcoma whereas knockdown of miR-221 reverses this phenotype, suggesting that miR-221 could be a potential target for osteosarcoma treatment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Implant design for the correction of osteoporotic unstable intertrochanteric fractures in elderly patients is a controversial issue. Our study aims to compare the efficacy of PFNA and cementless ...bipolar hemiarthroplasty (CBH) in treating osteoporotic unstable intertrochanteric fractures in the elderly.
We retrospectively assessed 70 elderly patients, aged > 70 years old, with intertrochanteric fractures (AO/OTA 31-A2 fractures) from 2014 to 2019. Among them, 34 patients received PFNA and 36 patients received CBH, accompanied with 2-year follow-ups. Additionally, the efficacy difference between the two implants was compared.
Both groups had similar general variables like age, gender, fracture site, degree of osteoporosis, fracture classification, ASA score, basic diseases, preoperative preparation time, anesthesia mode, amount of postoperative blood loss, hospital length of stay, along with postoperative blood transfusions and postoperative complications (P > 0.05). Conversely, significant differences were observed among intraoperative variables (amount of blood loss, amount of blood transfusions, operative time, number of intraoperative fluoroscopy), postoperative variables (weight-bearing time out of bed), and Harris hip function score within 12 months of operation (P < 0.05).
CBH showed no obvious advantage over PFNA in the perioperative period in elderly patients with osteoporotic unstable intertrochanteric fractures. However, the joint replacement allowed for earlier ambulation after the operation and rapid recovery of the hip joint function.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Cellular adaptation to a hypoxic microenvironment is essential for tumor progression and is largely mediated by HIF-1α through coordinated regulation of hypoxia-responsive genes. The chemokine SDF-1α ...and its unique receptor CXCR4 have been implicated in organ-specific metastases of many cancers. In this study, we investigated the response of osteosarcoma cells to hypoxia and the expression of CXCR4 and HIF-1α in human osteosarcoma specimens and explored the roles of CXCR4 and HIF-1α in the cell migration process.
We performed immunohistochemistry, immunocytochemistry, quantitative real-time PCR, Western blots and fluorescent reporter assays to evaluate the correlation between CXCR4 and HIF-1α expression in human osteosarcoma specimens or SOSP-9607 cells under normoxic and hypoxic conditions. Transwell assays were used to assess cell migration under different conditions. Exposure of SOSP-9607 cells to hypoxic conditions resulted in significantly increased migration. When SOSP-9607 cells were subjected to hypoxic conditions, the mRNA and protein levels of CXCR4 were significantly increased in a time-dependent manner. Moreover, siHIF-1α significantly decreased the mRNA and protein levels of CXCR4 under hypoxia, whereas pcDNA-HIF-1α significantly increased the mRNA and protein levels of CXCR4 under normoxia. A luciferase reporter gene study showed that siHIF-1α reduced pGL3-CXCR4 luciferase activity. Furthermore, coexpression of HIF-1α and CXCR4 was significantly higher in patients with distant metastasis compared with those without metastasis.
The hypoxia-HIF-1α-CXCR4 pathway plays a crucial role during the migration of human osteosarcoma cells, and targeting this pathway might represent a novel therapeutic strategy for patients suffering from osteosarcoma.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Catalpol is a natural product with promising anti-inflammatory effects, however, its effects on chondrocytes and osteoarthritis (OA) have not been well investigated. OA is a painful and debilitating ...joint disease that affects people worldwide. Traditional Chinese Medicine has been sought to treat OA, including the Rehmannia extract, Catalpol. Here, we examined the effects of Catalpol, a plant derivative used in traditional Chinese medicine, on ATDC5 chondrocytes originating from mouse teratocarcinoma cells stimulated with interleukin-1β (IL-1β) to mimic the OA cellular environment. Catalpol significantly reduced matrix metalloproteinase-1, -3, -13 (MMP-1, -3, -13), a disintegrin and metalloproteinase with thrombospondin motifs -4, -5 (ADAMTS-4, -5) against IL-1β, demonstrating a likely anti-cartilage degradation activity. We also found that Catalpol exerted a significant anti-oxidative stress effect by downregulating the production of inducible nitric oxide synthase (iNOS), nitric oxide (NO), reactive oxygen species (ROS), and malondialdehyde (MDA). Catalpol treatment significantly reduced the levels of several key inflammatory factors, including Prostaglandin E₂ (PGE₂), cyclooxygenase-2 (COX-2), interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1). We further demonstrate that the effects of Catalpol were mediated by the nuclear factor -κB (NF-κB) pathway via downregulation of the phosphorylation of inhibitor of nuclear factor κB-α (IκBα). This was confirmed by measuring p38 and p65 protein levels as well as the luciferase activity of NF-κB. Altogether, we demonstrate the potential of Catalpol as a novel treatment agent against cartilage matrix degradation, oxidative stress, and inflammation in OA.
Metastasis is a leading cause of mortality for osteosarcoma patients. The molecular pathological mechanism remains to be elucidated. In the previously study, we established two osteosarcoma cell ...lines with different metastatic potentials. Differential expressed genes and proteins regarding metastatic ability have been identified. MicroRNAs are important regulators in tumorigenesis and tumor progression. In this study, microRNA microarray was used to assess the differential expressed miRNAs level between these two cell lines. One of the top ranked miRNAs-miR-195 was identified highly expressing in lowly metastatic cells. It was showed that over-expression of miR-195 substantially inhibits migration and invasion of osteosarcoma cells in vitro and pulmonary metastasis formation in vivo. Meanwhile, CCND1 was identified as the target gene of miR-195 and further studied. More importantly, using real-time PCR, we evaluated the expression of miR-195 and CCND1 in osteosarcoma samples from 107 frozen biopsy tissues and 99 formalin- or paraformalin-fixed, paraffin-embedded (FFPE) tissues. Results indicated lowly expressed miR-195 or highly CCND1 correlated with positive overall survival and their expression inversely related to each other. In summary, our study suggests miR-195 functions as a tumor metastasis suppressor gene by down-regulating CCND1 and can be used as a potential target in the treatment of osteosarcoma.
Studies have shown that miR-194 functions as a tumor suppressor and is associated with tumor growth and metastasis. We studied the effects of miR-194 in osteosarcoma and the possible mechanism by ...which miR-194 affected the survival, apoptosis and metastasis of osteosarcoma. Both human osteosarcoma cell lines SOSP-9607 and U2-OS were transfected with recombinant lentiviruses to regulate miR-194 expression. Overexpression of miR-194 partially inhibited the proliferation, migration, and invasion of osteosarcoma cells in vitro, as well as tumor growth and pulmonary metastasis of osteosarcoma cells in vivo. Potential miR-194 target genes were predicted using bioinformatics. Luciferase reporter assay, real-time quantitative PCR and western blotting confirmed that CDH2 (N-cadherin) and IGF1R were targets of miR-194. Using real-time quantitative PCR, we evaluated the expression of miR-194 and two miR-194 target genes, CDH2 and IGF1R in osteosarcoma samples from 107 patients and 99 formalin- or paraformalin-fixed paraffin-embedded tissues. The expressions of the target genes were also examined in osteosarcoma samples using immunohistochemistry. Overexpression of miR-194 inhibited tumor growth and metastasis of osteosarcoma probably by downregulating CDH2 and IGF1R. miR-194 may prove to be a promising therapeutic agent for osteosarcoma.
...the histograms in panel C and D have changed slightly. (2013) Correction: MicroRNA-221 Induces Cell Survival and Cisplatin Resistance through PI3K/Akt Pathway in Human Osteosarcoma.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
OBJECTIVE The senescence and death of nucleus pulposus (NP) cells are the pathologic basis of intervertebral disc degeneration (IVD). To investigate the molecular phenotypes and senescent mechanism ...of NP cells, and to identify the method of alleviating senescence of NP cells.
The primary NP cells were harvested from male Sprague Dawley rats (8-10 weeks old); the hypoxia inducible factor 1alpha(HIF-1alpha, HIF-1beta matrix metalloproteinase 2 (MMP-2), and collagen type II as phenotypic markers were identified through immunocytochemical staining. RT-PCR and Western blot were used to test the silencing effect of NP cells after the NP cells were transfected with p53 and p21 small interference RNA (siRNA). Senescence associated-beta-galactosidase (SA-beta-gal) staining was used to test the senescence of NP cells, flow cytometry to test the change of cell cycle, the growth curve analysis to test the NP cells proliferation.
Immunocytochemical staining showed that NP cells expressed HIF-1alpha HIF-1beta, MMP-2, and c
Osteoarthritis (OA) is a common degenerative joint disease; however, its underlying pathogenesis remains to be elucidated. Previous studies have demonstrated that the transforming growth factor-beta ...(TGF-beta) signaling pathway has a role in the initiation and development of OA. Additionally, latent TGF-beta-binding protein-1 (LTBP-1) modulates the activity of the TGF-beta-mothers against decapentaplegic (Smad) signaling pathway in numerous diseases, including malignant glioma. The present study demonstrated that expression of LTBP-1 is increased in OA synovial tissues compared with normal synovial tissues. The effect of TGF-beta was identified to be mediated by phosphorylated(p)-(Smad)2/3, which may activate activin-like kinase (ALK)5 receptor, and by p-Smad1/5/8, which may induce ALK1, thereby stimulating expression of matrix metalloproteinase-(MMP)-13 in OA fibroblast-like synoviocytes (FLS). Compared with normal FLS, OA FLS demonstrated an increased p-Smad1/5/8:p-Smad2 ratio, which led to elevated MMP-13 expression and aggravation of OA. Furthermore, knockdown of the LTBP-1 gene by siRNA transfection in OA FLS reduced p-Smad1/5/8 expression without affecting TGF-beta mRNA levels, although p-Smad2 expression increased. It was also demonstrated that OA FLS exhibited increased proliferation compared with normal FLS in vitro. Furthermore, siRNA-mediated downregulation of LTBP-1 reduced proliferation of OA FLS. In conclusion, the present study demonstrated that an alteration in the p-Smad1/5/8:p-Smad2 ratio as well as association between p-Smad1/5/8 and MMP-13 expression in human OA FLS, may contribute to the development of OA. The results of the present study suggested that LTBP-1 is a modulator of the TGF-beta signaling pathway in human OA FLS, which may aid in elucidating the mechanism underlying the pathology of OA. Key words: osteoarthritis, fibroblast-like synoviocytes, latent transforming growth factor-beta-binding protein-1, transforming growth factor-beta, mothers against decapentaplegic homolog signaling
Osteoarthritis (OA) is a common degenerative joint disease; however, its underlying pathogenesis remains to be elucidated. Previous studies have demonstrated that the transforming growth factor‑β ...(TGF‑β) signaling pathway has a role in the initiation and development of OA. Additionally, latent TGF‑β‑binding protein‑1 (LTBP‑1) modulates the activity of the TGF‑β‑mothers against decapentaplegic (Smad) signaling pathway in numerous diseases, including malignant glioma. The present study demonstrated that expression of LTBP‑1 is increased in OA synovial tissues compared with normal synovial tissues. The effect of TGF‑β was identified to be mediated by phosphorylated(p)‑(Smad)2/3, which may activate activin‑like kinase (ALK)5 receptor, and by p‑Smad1/5/8, which may induce ALK1, thereby stimulating expression of matrix metalloproteinase‑(MMP)‑13 in OA fibroblast‑like synoviocytes (FLS). Compared with normal FLS, OA FLS demonstrated an increased p‑Smad1/5/8:p‑Smad2 ratio, which led to elevated MMP‑13 expression and aggravation of OA. Furthermore, knockdown of the LTBP‑1 gene by siRNA transfection in OA FLS reduced p‑Smad1/5/8 expression without affecting TGF‑β mRNA levels, although p‑Smad2 expression increased. It was also demonstrated that OA FLS exhibited increased proliferation compared with normal FLS in vitro. Furthermore, siRNA‑mediated downregulation of LTBP‑1 reduced proliferation of OA FLS. In conclusion, the present study demonstrated that an alteration in the p‑Smad1/5/8:p‑Smad2 ratio as well as association between p‑Smad1/5/8 and MMP‑13 expression in human OA FLS, may contribute to the development of OA. The results of the present study suggested that LTBP‑1 is a modulator of the TGF‑β signaling pathway in human OA FLS, which may aid in elucidating the mechanism underlying the pathology of OA.
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![Modulation of TGF-[beta] ac...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1791-2997/small "Modulation of TGF-[beta] activity by latent TGF-[beta]-binding protein 1 in human osteoarthritis fibroblast-like synoviocytes")
