NAMPT enhances LOX expression and promotes metastasis in human chondrosarcoma cells by inhibiting miR-26b-5p synthesis.

Chondrosarcoma is a malignant bone tumor that emerges from abnormalities in cartilaginous tissue and is related with lung metastases. Nicotinamide phosphoribosyltransferase (NAMPT) is an adipocytokine reported to enhance tumor metastasis. Our results from clinical samples and the Gene Expression Omnibus data set reveal that NAMPT levels are markedly higher in chondrosarcoma patients than in normal individuals. NAMPT stimulation significantly increased lysyl oxidase (LOX) production in chondrosarcoma cells. Additionally, NAMPT increased LOX-dependent cell migration and invasion in chondrosarcoma by suppressing miR-26b-5p generation through the c-Src and Akt signaling pathways. Overexpression of NAMPT promoted chondrosarcoma metastasis to the lung in vivo. Furthermore, knockdown of LOX counteracted NAMPT-facilitated metastasis. Thus, the NAMPT/LOX axis presents a novel target for treating the metastasis of chondrosarcoma.

The joint effects of physical activity and sleep duration on risk of osteoporosis in Taiwanese adult population: The Taiwan Biobank Study.

Most studies investigating the association between physical activity and osteoporosis prevention only focused on specific types of physical activity. This study's evidence regarding the combined effects or interaction of sleep duration and physical activity. The findings emphasize the role of sleep duration and physical activity in association with osteoporosis. PURPOSE: The associations between physical activity, sleep duration, and prevalent osteoporosis in Taiwanese adults were studied in this cross-sectional study. METHODS: The Taiwan Biobank enrolled a community-based cohort of ~ 120,000 volunteers (as of April 30, 2020) between 30 and 76 years of age with no history of cancer. Amongst, bone mineral density (BMD) measures by dual-energy X-ray absorptiometry (DXA) were available in 22,402 participants. After excluding individuals who had no complete data of BMI (n = 23), MET score (n = 207), T-score (n = 8,826), and sleep duration (n = 16), 13,330 subjects were included as the primary cohort. Univariate and multivariable regression analyses were performed to determine the associations between the presence of osteoporosis, physical activity level, sleep duration, and other variables. RESULTS: The results showed that after adjustment, subjects with physical activity < 20 METs/week and ≥ 20 METs/week (aOR = 1.017 and 0.767, respectively) were associated with risk of osteoporosis than those with zero MET. The odds of osteoporosis were not significantly lower in subjects who slept for ≥ 8 h/day (aOR = 0.934,p=0.266). In addition, compared to short sleepers with no physical activity, adults with increased physical activity ≥ 20 METs/week and sleep ≥ 8 h/day had a significantly lowest likelihood of osteoporosis (aOR = 0.702). Those with medium physical activity (< 20 METs/week) plus average sleep duration (6.5-8 h/day) did not have significant higher odds of osteoporosis (aOR = 1.129,p=0.151). CONCLUSION: The findings emphasize the joint role of sleep duration and physical activity in association with osteoporosis. Adults with high physical activity plus high sleep hours have the highest BMD and lowest risk of osteoporosis.

The stimulation of exosome generation by visfatin polarizes M2 macrophages and enhances the motility of chondrosarcoma.

Chondrosarcoma is a malignant bone tumor that arises from abnormalities in cartilaginous tissue and is associated with lung metastases. Extracellular vesicles called exosomes are primarily used as mediators of intercellular signal transmission to control tumor metastasis. Visfatin is an adipokine reported to enhance tumor metastasis, but its relationship with exosome generation in chondrosarcoma motility remains undetermined. Our results found that overexpressing visfatin augments the production of exosomes from chondrosarcoma cells. Visfatin-treated chondrosarcoma exosomes educate macrophage polarization towards the M2 but not M1 phenotype. Interestingly, M2 macrophages polarized by exosomes return to chondrosarcoma cells to facilitate cell motility. According to these findings, chondrosarcoma cells emit more exosomes when treated with visfatin. The stimulation of exosome generation by visfatin polarizes M2 macrophages and enhances the motility of chondrosarcoma.

Visfatin Facilitates VEGF-D-Induced Lymphangiogenesis through Activating HIF-1α and Suppressing miR-2277-3p in Human Chondrosarcoma.

Chondrosarcoma is a malignant bone tumor that arises from abnormalities in cartilaginous tissue and is associated with lung metastases. Lymphangiogenesis plays an essential role in cancer metastasis. Visfatin is an adipokine reported to enhance tumor metastasis, but its relationship with VEGF-D generation and lymphangiogenesis in chondrosarcoma remains undetermined. Our results from clinical samples reveal that VEGF-D levels are markedly higher in chondrosarcoma patients than in normal individuals. Visfatin stimulation promotes VEGF-D-dependent lymphatic endothelial cell lymphangiogenesis. We also found that visfatin induces VEGF-D production by activating HIF-1α and reducing miR-2277-3p generation through the Raf/MEK/ERK signaling cascade. Importantly, visfatin controls chondrosarcoma-related lymphangiogenesis in vivo. Therefore, visfatin is a promising target in the treatment of chondrosarcoma lymphangiogenesis.

Melatonin inhibits chondrosarcoma cell proliferation and metastasis by enhancing miR-520f-3p production and suppressing MMP7 expression.

Chondrosarcoma has a high propensity to metastasize and responds poorly to chemotherapy and radiation treatment. The enzymatic activity of matrix metalloproteinases (MMPs) is very important in chondrosarcoma metastasis. Melatonin exhibits anticarcinogenic activity in many types of cancers by suppressing the expression of certain MMP family members, but this has not yet been clearly determined in chondrosarcoma. Our study demonstrates that MMP7 plays an essential role in chondrosarcoma cell proliferation, migration, and anoikis resistance. We also found that MMP7 is highly expressed in chondrosarcomas. Our in vitro and in vivo investigations show that melatonin strongly inhibits chondrosarcoma cell proliferation, migration, and anoikis resistance by directly suppressing MMP7 expression. Melatonin reduced MMP7 synthesis by promoting levels of miR-520f-3p expression, which were downregulated in human chondrosarcoma tissue samples. Pharmacological inhibition of miR-520f-3p markedly reversed the effects of melatonin upon chondrosarcoma proliferation and metastasis. Thus, our study suggests that melatonin has therapeutic potential for reducing the tumorigenesis and metastatic potential of chondrosarcoma via the miR-520f-3p/MMP7 axis.

The association between the severity of periodontitis and osteonecrosis of the jaw in patients with different cancer locations: a nationwide population-based study.

OBJECTIVES: To determine the relation between the severity of periodontitis and osteonecrosis of the jaw (ONJ) occurrence among different cancer locations and estimate the effect of dental care on ONJ prevention in cancer patients. MATERIALS AND METHODS: This population-based cross-sectional study was conducted through the Longitudinal Health Insurance Database, Taiwan. Patients with malignancies were collected and subdivided into groups according to their different cancer locations, the severity of periodontitis, and dental care. Multivariable logistic regression analysis was performed to assess the associations between ONJ and ONJ-related factors. RESULTS: A total of 8,234 ONJ patients and 32,912 control patients were investigated. Lip, oral cavity, and pharynx malignancies had the highest ONJ risk among all cancer locations (OR from 3.07 to 9.56, P < 0.01). There is a linear relationship between different severities of periodontitis and ONJ. Patients with radiotherapy and severe periodontitis had the highest ONJ risk (adjusted OR, 9.56; 95% CI, 5.34-17.1). Patients with good dental care had a lower ONJ risk. CONCLUSIONS: The periodontal condition and cancer location showed a significant impact on the risk of developing ONJ after adjusting for bisphosphonate use. Good dental care could decrease the risk of ONJ in cancer patients. The severity of periodontitis might be a target to predict the potency of ONJ. CLINICAL RELEVANCE: Dentists must be vigilant about the increased risk of ONJ in cancer patients with periodontitis, especially in the head and neck cancer population. Good dental care is advised for cancer patients with severe periodontitis.

Posterior-Stabilized Antibiotic Cement Articulating Spacer With Endoskeleton-Reinforced Cam Reduces Rate of Post-Cam Mechanical Complications in Prosthetic Knee Infection: A Preliminary Study.

BACKGROUND: Posterior-stabilized antibiotic cement articulating spacers (PS spacers) reduce spacer mechanical complications in prosthetic knee infections (PKIs); however, joint dislocation after femoral cam fracture has been reported. We hypothesized that the rate of post-cam mechanical complications is lower in PS spacers with an endoskeleton-reinforced cam. METHOD: A retrospective study of PKIs using PS spacers with or without a Kirschner wire-reinforced cam (K-PS or nK-PS spacers, respectively) was conducted between 2015 and 2019. The rates of post-cam mechanical complications and reoperation, as well as risk factors for post or cam failure, were analyzed. RESULTS: The cohort included 118 nK-PS and 49 K-PS spacers. All patients were followed up for 2 years. The rate of joint subluxation/dislocation after femoral cam fracture was lower in K-PS (0%) than in nK-PS spacers (17.8%; P = .002). The reoperation rate for spacer mechanical complications was lower in K-PS (0%) than in nK-PS spacers (11.9%; P = .008). The identified risk factors for femoral cam fractures were body mass index ≥25 kg/m2, femoral spacer size ≤2, and surgical volume ≤12 resection arthroplasties per year. CONCLUSION: This preliminary study highlights that K-PS spacers have a lower rate of post-cam mechanical complications than nK-PS spacers. We recommend the use of PS spacers with endoskeleton-reinforced cam when treating PKIs performed by surgeons with lower surgical volumes, especially in patients with higher body mass index and smaller femoral spacer sizes.

IL-17 Facilitates VCAM-1 Production and Monocyte Adhesion in Osteoarthritis Synovial Fibroblasts by Suppressing miR-5701 Synthesis.

Osteoarthritis (OA) is characterized by the infiltration and adhesion of monocytes into the inflamed joint synovium. Interleukin (IL)-17 is a critical inflammatory mediator that participates in the progression of OA, although the mechanisms linking IL-17 and monocyte infiltration are not well understood. Our analysis of synovial tissue samples retrieved from the Gene Expression Omnibus (GEO) dataset exhibited higher monocyte marker (CD11b) and vascular cell adhesion molecule 1 (VCAM-1) levels in OA samples than in normal, healthy samples. The stimulation of human OA synovial fibroblasts (OASFs) with IL-17 increased VCAM-1 production and subsequently enhanced monocyte adhesion. IL-17 affected VCAM-1-dependent monocyte adhesion by reducing miR-5701 expression through the protein kinase C (PKC)-α and c-Jun N-terminal kinase (JNK) signaling cascades. Our findings improve our understanding about the effect of IL-17 on OA progression and, in particular, VCAM-1 production and monocyte adhesion, which may help with the design of more effective OA treatments.

DPP4 reduces proinflammatory cytokine production in human rheumatoid arthritis synovial fibroblasts.

Rheumatoid arthritis (RA) is an autoimmune disorder that is characterized by increasing levels of proinflammatory cytokines. The ubiquitous enzyme dipeptidyl peptidase-4 (DPP4, also known as CD26) regulates different immune disorders, although the effects of DPP4 in RA are uncertain. Here, we found lower levels of DPP4 in RA synovial tissues compared with normal tissues. DPP4 levels were also lower in a rat collagen-induced arthritis model than in control (healthy) rats. Overexpression of DPP4 or exogenous treatment of RA synovial fibroblasts with DPP4 reduced levels of proinflammatory interleukin (IL)-1ß, IL-6, and IL-13, and increased anti-inflammatory IL-10 synthesis, while DPP4 inhibitors sitagliptin and vildagliptin increased proinflammatory cytokine production, indicating an enhanced risk of RA development. The evidence suggests that increasing DPP4 expression is a novel strategy for RA disease.

miR-144-3p ameliorates the progression of osteoarthritis by targeting IL-1ß: Potential therapeutic implications.

The pro-inflammatory cytokine interleukin 1 beta (IL-1ß) plays a critical role in osteoarthritis (OA) disease pathogenesis. MicroRNA (miRNA) activity is related to inflammation in OA and some miRNAs specifically regulate IL-mediated degradation of cartilage type II collagen. Previous studies have indicated that miR-144-3p is a useful target in the regulation of pro-inflammatory cytokines in different diseases. However, the role of miR-144-3p in OA is unclear. In this study, we observed a negative correlation between miR-144-3p and IL-1ß expression in OA. miR-144-3p mimic transfection of OA synovial fibroblasts downregulated levels of IL-1ß expression, while blocking the MAPK, PI3K/Akt, and NF-κB signaling pathways relating to IL-1ß production, and effectively increased miR-144-3p expression in OASFs. Findings from an anterior cruciate ligament transection rat model revealed that administration of miR-144-3p mimic effectively ameliorated OA progression and reduced the numbers of IL-1ß-positive cells in synovial tissue. This study suggests that miR-144-3p is a useful therapeutic target in OA disease.

Resistin enhances IL-1ß and TNF-α expression in human osteoarthritis synovial fibroblasts by inhibiting miR-149 expression via the MEK and ERK pathways.

Resistin is a cysteine-rich adipokine that promotes the release of inflammatory cytokines, particularly interleukin 1 beta (IL-1ß) and tumor necrosis factor alpha (TNF-α), which are critical pro-inflammatory mediators in osteoarthritis (OA) pathogenesis. We describe evidence of significantly higher levels of resistin, IL-1ß, and TNF-α expression in OA knee synovial tissue compared with that from non-OA knees. Resistin-induced enhancement of IL-1ß and TNF-α expression in human OA synovial fibroblasts (OASFs) were attenuated by MEK and ERK inhibitors, as well as their respective siRNAs. Our data reveal that resistin enhances the expression of TNF-α and IL-1ß in OASFs by inhibiting miR-149 expression via MEK and ERK signaling. Our findings elucidate the inter-relationships between resistin and pro-inflammatory mediators during OA pathogenesis and could help to facilitate the development of synovium-targeted therapy in OA.

The impact of timing and modalities of dental prophylaxis on the risk of 5-fluorouracil-related oral mucositis in patients with head and neck cancer: a nationwide population-based cohort study.

PURPOSE: This study investigated the impact of dental prophylaxis on 5-fluorouracil (5-FU)-related oral mucositis (OM) according to the head and neck cancer (HNC) locations and treatment times. METHODS: A total of 13,969 HNC participants, including 482 5-FU-related OM subjects and 13,487 comparisons were enrolled from the Longitudinal Health Insurance Database for Catastrophic Illness Patients of Taiwan between 2000 and 2008. All subjects were stratified into subgroups based on the times to perform chlorhexidine use, scaling, and fluoride application before 5-FU administration. The dental prophylaxis related to 5-FU-related OM was estimated by multiple logistic regression and represented with odds ratio (OR) and 95% confidence interval (CI). RESULTS: Fluoride gel application and scaling significantly impacted on OM development (p < 0.001), and the joint effect of fluoride gel and scaling induced 5-FU-related OM (OR = 3.46, 95% CI = 2.39-5.01). The risk of OM was raised 2.25-fold as scaling within 3 weeks before 5-FU-related chemotherapy (95% CI = 1.81-2.81), and a 3.22-fold increased risk of OM while fluoride gel was applied during 5-FU-related treatment (95% CI = 1.46-7.13). CONCLUSION: Dental prophylaxis significantly affected 5-FU-related OM in the HNC population. A short interval between dental scaling or fluoride application and 5-FU administration may be associated with higher prevalence of OM. Scaling simultaneously combined with chlorohexidine promoted 5-FU-related OM in specific HNC patients excluding the oral cancer and nasopharyngeal cancer population. Proper timing of the prophylactic dental treatments prior to 5-FU therapy could reduce the risk to develop 5-FU-related OM.

Safety and efficacy of single CHAP Hyaluronan injection versus three injections of linear Hyaluronan in pain relief for knee osteoarthritis: a prospective, 52-week follow-up, randomized, evaluator-blinded study.

BACKGROUND: The hyaluronic acid (HA) injections are widely used in knee osteoarthritis (OA) patients. We conducted the study comparing the efficacy and safety of single injection of Crosslinked Hyaluronic Acid Platform Hyaluronan (CHAP-HA) with 3-injection of linear hyaluronan in knee OA patients. METHODS: This was a randomized two-arms, evaluator-blinded, controlled, single-center study. Participants with knee OA received single CHAP-HA or three-injection of linear-HA. The 140 patients aged 35-85 years with radiographically confirmed knee OA were enrolled. At week 4, 12, 26, 39, and 52, visual analog scale (VAS) pain score, Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index, timed up and go (TUG) and subject's adverse events (AE) of these 2 groups were recorded. Primary outcome of the differences of VAS pain score at week 26 between groups was analyzed with analysis of covariance (ANCOVA). At week 52, those who met the inclusion criteria could receive a CHAP-HA injection and being followed-up for the adverse events for 4 weeks. RESULTS: The trial was conducted from September 2015 to April 2017. A total 140 subjects were available for analysis (71 in the CHAP-HA group and 69 in the linear-HA group). At 26th week, there were significant more improvements in VAS pain scores in CHAP-HA compared with linear-HA. Both CHAP-HA and linear-HA showed significant improvements in the VAS pain score at week 26 compared with the baseline, and the occurrence of adverse events during the study period showed no between-group difference. In subjects with KL = 2, both groups showed significant improvements in VAS pain scores within 26 weeks. In patients with KL = 3, only CHAP-HA group showed significant improvement in VAS pain from 4 to 39 weeks. No unexpected or severe AEs were reported. CONCLUSIONS: A single injection of CHAP-HA may be safe and more effective for 26 weeks in patients with knee OA by comparing to linear-HA; moreover, the pain relief effect of CHAP-HA may remain until 52 weeks. For patients with more severe OA, CHAP-HA was demonstrated to be more preferable to relieve OA pain. Furthermore, repeat treatment of CHAP-HA or using CHAP-HA after a three-injection HA was proved to be safe. TRIAL REGISTRATION: ClinicalTrials.gov : NCT03643588 . Date: August 23, 2018 (retrospectively registered). LEVEL OF EVIDENCE: Therapeutic Level I.

Bidirectional relationship between temporomandibular disorder and ankylosing spondylitis: a population-based cohort study.

OBJECTIVES: This study aimed to determine the relation between temporomandibular disorder (TMD) and ankylosing spondylitis (AS) bidirectionally and ascertain the important comorbidities for AS occurrence in TMD patients. MATERIALS AND METHODS: We conducted this population-based cohort study through Longitudinal Health Insurance Database, Taiwan. Study 1 investigated the risk of TMD in AS patients. Study 2 assessed the risk of AS in TMD patients. RESULTS: In total, 3204 AS patients and 12,816 age-matched and gender-matched comparisons were enrolled in study 1. The TMD incidence in the AS cohort was 2.88-fold higher when compared with the comparisons (1.54 vs. 0.53 per 10,000 person-years). After adjusting for age, gender, and comorbidity, the AS cohort had a 2.66-fold (95% CI = 1.79-3.97) increased risk of TMD occurrence (P < 0.0001). The second study recruited 4998 TMD patients and 19,991 age-matched and gender-matched comparisons. Both TMD and comparison cohorts showed similar AS risk (HR = 1.49, 95% CI = 0.91-2.43, P = 0.1108) in the adjusted model. Study 2 identified a 3.66-fold increased risk of AS occurrence in TMD patients with comorbidity, including parapsoriasis, rheumatoid arthritis, osteoporosis, Cushing's syndrome, and climacteric arthritis (P < 0.012). CONCLUSIONS: AS appears to significantly impact the occurrence of TMD. TMD might play a synergic role in AS development. CLINICAL RELEVANCE: Clinicians have to be vigilant about the increased risk of TMD in AS patients and take care of AS disease activity and prognosis. The symptoms and signs of TMD could be a predictor of AS in patients with the aforementioned comorbidities.

Cruciate-Retaining vs Posterior-Stabilized Antibiotic Cement Articulating Spacers for Two-Stage Revision of Prosthetic Knee Infection: A Retrospective Cohort Study.

BACKGROUND: Antibiotic cement articulating spacers are recommended during 2-stage revision for prosthetic knee infection because of increased range of motion (ROM) and improved function; however, spacer mechanical complications have been reported. We aimed to determine the association between different constraints of articulating spacers and the rate of complications and infection eradication, functional outcomes, and ROM. METHODS: A retrospective study of prosthetic knee infection using cruciate-retaining (CR) or posterior-stabilized (PS) spacers was conducted between 2011 and 2018. The rate of spacer mechanical complications, infection eradication after reimplantation and reoperation, Hospital of Special Surgery (HSS) knee score, and ROM during the interim stage were analyzed. All patients were regularly followed up for 2 years. RESULTS: One hundred forty-one patients were included, with 66 CR and 75 PS spacers. Overall mechanical complication rate was lower in PS (9.3%) than in CR spacers (45.5%) (P < .001), especially in joint dislocation (1.3% vs 30.3%, respectively, P < .001). Overall reoperation rate was lower in PS (16.0%) than in CR spacers (36.4%) (P < .001), especially for mechanical complications (1.3% vs 24.2%, respectively, P < .001). HSS knee score was higher in PS (72.3) than in CR spacers (63.8) (P < .001). ROM was greater in PS (90.3°) than in CR spacers (80.6°) (P = .005), especially at maximum flexion (102.4° vs 89.6°, respectively, P = .003). Infection eradication was comparable between the spacers. CONCLUSION: Both spacers can control infection; however, PS spacers had a lower rate of mechanical complications and reoperation, better HSS knee scores, and greater ROM than CR spacers.

The Effects of Tgfb1 and Csf3 on Chondrogenic Differentiation of iPS Cells in 2D and 3D Culture Environment.

Mesenchymal stem (MS) cells, embryonic stem (ES) cells, and induced pluripotent stem (iPS) cells are known for their ability to differentiate into different lineages, including chondrocytes in culture. However, the existing protocol for chondrocyte differentiation is time consuming and labor intensive. To improve and simplify the differentiation strategy, we have explored the effects of interactions between growth factors (transforming growth factor ß1 (Tgfb1) and colony stimulating factor 3 (Csf3), and culture environments (2D monolayer and 3D nanofiber scaffold) on chondrogenic differentiation. For this, we have examined cell morphologies, proliferation rates, viability, and gene expression profiles, and characterized the cartilaginous matrix formed in the chondrogenic cultures under different treatment regimens. Our data show that 3D cultures support higher proliferation rate than the 2D cultures. Tgfb1 promotes cell proliferation and viability in both types of culture, whereas Csf3 shows positive effects only in 3D cultures. Interestingly, our results indicate that the combined treatments of Tgfb1 and Csf3 do not affect cell proliferation and viability. The expression of cartilaginous matrix in different treatment groups indicates the presence of chondrocytes. We found that, at the end of differentiation stage 1, pluripotent markers were downregulated, while the mesodermal marker was upregulated. However, the expression of chondrogenic markers (col2a1 and aggrecan) was upregulated only in the 3D cultures. Here, we report an efficient, scalable, and convenient protocol for chondrogenic differentiation of iPS cells, and our data suggest that a 3D culture environment, combined with tgfb1 and csf3 treatment, promotes the chondrogenic differentiation.

S1P promotes IL-6 expression in osteoblasts through the PI3K, MEK/ERK and NF-κB signaling pathways.

Rheumatoid arthritis (RA) is a systemic autoimmune inflammatory disease, in which the immune system attacks joint tissue. Interleukin (IL)-6 is a key proinflammatory cytokine in RA progression. Sphingosine-1-phosphate (S1P), a platelet-derived lysophospholipid mediator, reportedly regulates osteoimmunology. Here, we examined the effects of S1P on IL-6 expression in osteoblasts. Our results and records from the Gene Expression Omnibus (GEO) database demonstrate higher levels of IL-6 in patients with RA compared with those with osteoarthritis. Stimulation of osteoblasts with S1P increased mRNA and protein expression of IL-6. PI3K, MEK, ERK and NF-κB inhibitors and their small interfering RNAs (siRNAs) reduced S1P-promoted IL-6 expression. S1P also facilitated PI3K, MEK/ERK and NF-κB signaling cascades. Our results indicate that S1P promotes the expression of IL-6 in osteoblasts via the PI3K, MEK/ERK and NF-κB signaling pathways.

S1P facilitates IL-1ß production in osteoblasts via the JAK and STAT3 signaling pathways.

Rheumatoid arthritis (RA) is a systemic autoimmune inflammatory disease, in which the immune system attacks synovial joint tissues. Interleukin (IL)-1ß is a critical proinflammatory cytokine in RA progression. Sphingosine-1-phosphate (S1P), a platelet-derived lysophospholipid mediator, reportedly regulates osteoimmunology. Here, we investigated how S1P mediates IL-1ß expression in osteoblasts. Our analysis of records from the Gene Expression Omnibus (GEO) database demonstrate higher levels of IL-1ß in patients with RA compared with those with osteoarthritis. Stimulation of osteoblasts with S1P concentration dependently increased mRNA and protein expression of IL-1ß. Elevations in IL-1ß mRNA expression induced by S1P were reduced by the small interfering RNA (siRNA) against the S1P1 receptor. S1P also augmented JAK and STAT3 molecular cascades. We also found that JAK and STAT3 inhibitors and their siRNAs antagonized S1P-promoted IL-1ß expression. Our results indicate that S1P promotes the expression of IL-1ß in osteoblasts via the S1P1 receptor and the JAK and STAT3 signaling pathways.

The association between dental therapy timelines and osteoradionecrosis: a nationwide population-based cohort study.

OBJECTIVES: The study aimed to investigate the timeline association with specific dental therapy and osteoradionecrosis (ORN) in oral cancer patients. MATERIALS AND METHODS: A total of 7394 oral cancer patients, including 198 ORN subjects, were retrieved from a Longitudinal Health Insurance Database for Catastrophic Illness Patients of Taiwan and were analyzed with the Cox proportional hazard regression to compare the ORN risk of individual dental treatments under different dental treatments. RESULTS: The initial dental treatment time significantly impacted on the risk of ORN in oral cancer patients (P<0.05). Pre-radiotherapy endodontic treatment and post-radiotherapy scaling or subgingival curettage increased ORN prevalence (hazard ratio [HR], 2.28 and 1.77, respectively). Endodontic treatment within 2 weeks to 1 month prior to radiotherapy increased the ORN risk by 5.83-fold. Dental scaling or subgingival curettage initialized from three to 6 months post-radiotherapy raised the ORN prevalence by 2.2-fold. Exodontia initialized within 2 weeks before radiotherapy (HR=1.49) or 1 to 3 months after radiotherapy (HR=2.63) greatly increased ORN prevalence. To perform oral surgery from 3 months pre-radiotherapy to 6 months after radiotherapy increased the 1.85-fold ORN risk. The chemotherapy combined oral surgery increased the ORN prevalence by 2.55-fold. CONCLUSIONS: Timing of dental treatment, including pre-radiotherapy endodontic treatment, post-radiotherapy scaling or subgingival curettage, and oral surgery or exodontia before and after radiotherapy, could closely relate to ORN development in oral cancer patients. CLINICAL RELEVANCE: Choosing right time to perform appropriate dental treatment could effectively reduce oral infection and ORN risk.

CCN2 promotes drug resistance in osteosarcoma by enhancing ABCG2 expression.

In recent years, osteosarcoma survival rates have failed to improve significantly with conventional treatment modalities because of the development of chemotherapeutic resistance. The human breast cancer resistance protein/ATP binding cassette subfamily G member 2 (BCRP/ABCG2), a member of the ATP-binding cassette family, uses ATP hydrolysis to expel xenobiotics and chemotherapeutics from cells. CCN family member 2 (CCN2) is a secreted protein that modulates the biological function of cancer cells, enhanced ABCG2 protein expression and activation in this study via the α6ß1 integrin receptor and increased osteosarcoma cell viability. CCN2 treatment downregulated miR-519d expression, which promoted ABCG2 expression. In a mouse xenograft model, knockdown of CCN2 expression increased the therapeutic effect of doxorubicin, which was reversed by ABCG2 overexpression. Our data show that CCN2 increases ABCG2 expression and promotes drug resistance through the α6ß1 integrin receptor, whereas CCN2 downregulates miR-519d. CCN2 inhibition may represent a new therapeutic concept in osteosarcoma.