CXCL13 promotes TNF-α synthesis in rheumatoid arthritis through activating ERK/p38 pathway and inhibiting miR-330-3p generation.

Rheumatoid arthritis (RA) is a well-known autoimmune disorder associated with joint pain, joint swelling, cartilage and bone degradation as well as deformity. The chemokine (C-X-C motif) ligand 13 (CXCL13) plays a crucial role in multiple cellular pathogenesis processes, including RA. TNF-α is a vital proinflammatory factor in the progression of RA. However, the role of CXCL13 in TNF-α production in RA has not been fully explored. Our analysis of both database and clinical samples revealed higher levels of CXCL13 and TNF-α in RA samples compared to healthy controls. CXCL13 concentration-dependently induces TNF-α synthesis in RA synovial fibroblasts. CXCL13 enhances TNF-α expression by interacting with the CXCR5 receptor, activating the ERK/p38 pathways, and inhibiting miR-330-3p generation. Importantly, treatment with CXCL13 shRNA counteracted the upregulation of TNF-α production induced by collagen-induced arthritis. Our findings support the notion that CXCL13 is a promising target in the treatment of RA.

Allyl isothiocyanate induces DNA damage and inhibits DNA repair-associated proteins in a human gastric cancer cells in vitro.

Allyl isothiocyanate (AITC) is abundant in cruciferous vegetables and it present pharmacological activity including anticancer activity in many types of human cancer cells in vitro and in vivo. Currently, no available information to show AITC affecting DNA damage and repair-associated protein expression in human gastric cancer cells. Therefore, in the present studies, we investigated AITC-induced cytotoxic effects on human gastric cancer in AGS and SNU-1 cells whether or not via the induction of DNA damage and affected DNA damage and repair associated poteins expressions in vitro. Cell viability and morphological changes were assayed by flow cytometer and phase contrast microscopy, respectively, the results indicated AITC induced cell morphological changes and decreased total viable cells in AGS and SNU-1 cells in a dose-dependently. AITC induced DNA condensation and damage in a dose-dependently which based on the cell nuclei was stained by 4', 6-diamidino-2-phenylindole present in AGS and SNU-1 cells. DNA damage and repair associated proteins expression in AGS and SNU-1 cells were measured by Western blotting. The results indicated AITC decreased nuclear factor erythroid 2-related factor 2 (NRF2), heme oxygenase-1 (HO-1), glutathione, and catalase, but increased superoxide dismutase (SOD (Cu/Zn)), and nitric oxide synthase (iNOS) in AGS cells, however, in SNU-1 cells are increased HO-1. AITC increased DNA-dependent protein kinase (DNA-PK), phosphorylation of gamma H2A histone family member X on Ser139 (γH2AXpSer139 ), and heat shock protein 90 (HSP90) in AGS cells. AITC increased DNA-PK, mediator of DNA damage checkpoint protein 1 (MDC1), γH2AXpSer139 , topoisomerase II alpha (TOPIIα), topoisomerase II beta (TOPIIß), HSP90, and heat shock protein 70 (HSP70) in SNU-1 cells. AITC increased p53, p53pSer15 , and p21 but decreased murine double minute 2 (MDM2)pSer166 and O6 -methylguanine-DNA methyltransferase (MGMT) in AGS cells; however, it has a similar effect of AITC except increased ataxia telangiectasia and Rad3 -related protein (ATR)pSer428 , checkpoint kinase 1 (CHK1), and checkpoint kinase 2 (CHK2) in SNU-1 cells. Apparently, both cell responses to AITC are different, nonetheless, all of these observations suggest that AITC inhibits the growth of gastric cancer cells may through induction off DNA damage in vitro.

Omentin-1 ameliorates the progress of osteoarthritis by promoting IL-4-dependent anti-inflammatory responses and M2 macrophage polarization.

Osteoarthritis (OA) is a prevalent joint disease commonly associated with aging and obesity, which can lead to pain, stiffness, joint dysfunction, and disability. Omentin-1 (also called intelectin-1) is a newly discovered adipokine, which plays a protective role in suppressing the secretion of pro-inflammatory cytokines. Based on data from the Gene Expression Omnibus (GEO) dataset and clinical samples obtained at our institution revealed, determined that omentin-1 and IL-4 (an anti-inflammatory cytokine) levels were significantly lower in OA patients than in normal controls. Omentin-1 was shown to induce IL-4-depedent anti-inflammatory responses and M2 macrophage polarization in OA synovial fibroblasts via the PI3K, ERK, and AMPK pathways. Administering omentin-1 was shown to block cartilage degradation and bone erosion resulting from anterior cruciate ligament transection by inhibiting the production of pro-inflammatory cytokines and promoting M2 macrophage polarization in vivo. Our findings indicate omentin-1 as a promising therapeutic avenue for the treatment for OA.

Glutamine metabolism controls amphiregulin-facilitated chemoresistance to cisplatin in human chondrosarcoma.

Chondrosarcoma is the second most common type of bone cancer. At present, the most effective clinical course of action is surgical resection. Cisplatin is the chemotherapeutic medication most widely used for the treatment of chondrosarcoma; however, its effectiveness is severely hampered by drug resistance. In the current study, we compared cisplatin-resistant chondrosarcoma SW1353 cells with their parental cells via RNA sequencing. Our analysis revealed that glutamine metabolism is highly activated in resistant cells but glucose metabolism is not. Amphiregulin (AR), a ligand of the epidermal growth factor receptor, enhances glutamine metabolism and supports cisplatin resistance in human chondrosarcoma by promoting NADPH production and inhibiting reactive oxygen species (ROS) accumulation. The MEK, ERK, and NrF2 signaling pathways were shown to regulate AR-mediated alanine-serine-cysteine transporter 2 (ASCT2; also called SLC1A5) and glutaminase (GLS) expression as well as glutamine metabolism in cisplatin-resistant chondrosarcoma. The knockdown of AR expression in cisplatin-resistant chondrosarcoma cells was shown to reduce the expression of SLC1A5 and GLS in vivo. These results indicate that AR and glutamine metabolism are worth pursuing as therapeutic targets in dealing with cisplatin-resistant human chondrosarcoma.

Chemokine Ligand 2 Promotes Migration in Osteosarcoma by Regulating the miR-3659/MMP-3 Axis.

Osteosarcoma is a common malignant tumor in children and adolescents, known for its aggressive invasion and distant metastasis, leading to a poor prognosis. Matrix metalloproteinases (MMPs) can degrade the extracellular matrix and basement membranes through their proteolytic activity, thereby promoting osteosarcoma metastasis. Chemokine ligand 2 (CCL2) is a well-studied chemokine that plays a significant role in the cell motility of many cancers. However, its specific involvement in osteosarcoma metastasis is not fully understood. The aim of this study is to examine the role of miRNAs in CCL2-mediated MMP expression and cell motility in human osteosarcoma. The analysis of immunohistochemistry data and databases associated a positive correlation between CCL2 or MMP-3 levels with the metastasis of osteosarcoma patients. The in vivo lung metastatic osteosarcoma model also demonstrated similar effects, showing higher levels of CCL2 and MMP-3 in lung metastatic osteosarcoma tissues. The stimulation of osteosarcoma cells with CCL2 enhanced migration and invasion abilities through the upregulation of MMP-3 synthesis. Our results also indicate that CCL2 enhances MMP-3-dependent cell motility by inhibiting miR-3659 synthesis. Therefore, CCL2 represents a promising therapeutic target for treating metastasis in osteosarcoma.

In Vitro Assessment of the Antioxidant and Anticancer Properties of Flammulina velutipes Stipe Extracts.

BACKGROUND/AIM: Flammulina velutipes (FV), also known as the golden needle mushroom, is an edible and medicinal fungus that contains bioactive substances regulating various physiological functions. While the fruiting bodies of FV are commonly consumed, their stipes are often discarded despite containing polysaccharides. In this study, the biological functions of FV stipes (FV-S) were investigated to reduce waste and pollution while increasing their value. MATERIALS AND METHODS: The antioxidant activity of FV was evaluated using three methods: the DPPH radical-scavenging capacity assay, ferrous ion chelating assay, and reducing power analysis. The anti-cancer potential was assessed through MTT viability and immunoblotting analyses. RESULTS: Results showed that FV-S had higher polysaccharide and total phenolic contents and greater antioxidant abilities, particularly in ethanolic extracts. FV-S also exhibited significant anticancer properties, specifically in hot water extracts with high polysaccharide contents, and suppressed prostate cancer cell viability by inhibiting androgen receptor and PCa-specific antigen mRNA expression while inducing caspase-3/7 activation. CONCLUSION: FV-S is rich in bioactive components, possesses higher antioxidant and anticancer abilities, and has potential as an anticancer agent, which could enhance the value of FV.

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.

IOX-1 suppresses metastasis of osteosarcoma by upregulating histone H3 lysine trimethylation.

New therapeutic approaches are needed for metastatic osteosarcoma (OS), as survival rates remain low despite surgery and chemotherapy. Epigenetic changes, such as histone H3 methylation, play key roles in many cancers including OS, although the underlying mechanisms are not clear. In this study, human OS tissue and OS cell lines displayed lower levels of histone H3 lysine trimethylation compared with normal bone tissue and osteoblast cells. Treating OS cells with the histone lysine demethylase inhibitor 5-carboxy-8-hydroxyquinoline (IOX-1) dose-dependently increased histone H3 methylation and inhibited cellular migratory and invasive capabilities, suppressed matrix metalloproteinase expression, reversed epithelial-to-mesenchymal transition by increasing levels of epithelial markers E-cadherin and ZO-1 and decreasing the expression of mesenchymal markers N-cadherin, vimentin, and TWIST, and also reduced stemness properties. An analysis of cultivated MG63 cisplatin-resistant (MG63-CR) cells revealed lower histone H3 lysine trimethylation levels compared with levels in MG63 cells. Exposing MG63-CR cells to IOX-1 increased histone H3 trimethylation and ATP-binding cassette transporter expression, potentially sensitizing MG63-CR cells to cisplatin. In conclusion, our study suggests that histone H3 lysine trimethylation is associated with metastatic OS and that IOX-1 or other epigenetic modulators present promising strategies to inhibit metastatic OS progression.

Apelin promotes osteosarcoma metastasis by upregulating PLOD2 expression via the Hippo signaling pathway and hsa_circ_0000004/miR-1303 axis.

Osteosarcoma is a highly mortal bone tumor, with a high metastatic potential, promoted in part by the enzyme procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 (PLOD2). Increasing level of PLOD2 in osteosarcoma tissue correlates with lymphatic and distant metastasis. The adipokine apelin (APLN) is also found in different cancers and APLN upregulation promotes angiogenesis and metastasis, but its effects on osteosarcoma metastasis are uncertain. We explored APLN functioning in metastatic osteosarcoma. An analysis of records from the Gene Expression Omnibus (GEO) database showed higher levels of APLN expression in osteosarcoma tissue than in normal tissue. Similarly, levels of APLN and PLOD2 mRNA synthesis were upregulated in osteosarcoma tissue. Levels of APLN and PLOD2 protein correlated positively with osteosarcoma clinical stages. APLN increased PLOD2 expression in human osteosarcoma cell lines and cell migration via the mammalian Sterile 20-like kinase 1 (MST1), monopolar spindle-one-binder protein (MOB)1, and YAP cascades, and through hsa_circ_0000004 functioning as a sponge of miR-1303. We also found that knockdown of APLN antagonized lung metastasis in mice with osteosarcoma. APLN may be a therapeutic target in osteosarcoma metastasis.

Identification of a novel interaction site between the large hepatitis delta antigen and clathrin that regulates the assembly of genotype III hepatitis delta virus.

BACKGROUND: Hepatitis delta virus (HDV), a satellite virus of hepatitis B virus (HBV), is a small, defective RNA virus strongly associated with the most severe form of hepatitis and progressive chronic liver disease and cirrhosis. Chronic hepatitis D, resulting from HBV/HDV coinfection, is considered to be the most severe form of viral hepatitis and affects 12-20 million people worldwide. Involved in the endocytosis and exocytosis of cellular and viral proteins, clathrin contributes to the pathogenesis and morphogenesis of HDV. Previously, we demonstrated that HDV-I and -II large hepatitis delta antigens (HDAg-L) possess a putative clathrin box that interacts with clathrin heavy chain (CHC) and supports HDV assembly. METHODS: Virus assembly and vesicular trafficking of HDV virus-like particles (VLPs) were evaluated in Huh7 cells expressing HDV-I, -II and -III HDAg-L and hepatitis B surface antigen (HBsAg). To elucidate the interaction motif between HDAg-L and CHC, site-directed mutagenesis was performed to introduce mutations into HDAg-L and CHC and analyzed using coimmunoprecipitation or pull-down assays. RESULTS: Comparable to HDV-I virus-like particles (VLPs), HDV-III VLPs were produced at a similar level and secreted into the medium via clathrin-mediated post-Golgi vesicular trafficking. Mutation at F27 or E33 of CHC abolished the binding of CHC to the C-terminus of HDV-III HDAg-L. Mutation at W207 of HDV-III HDAg-L inhibited its association with CHC and interfered with HDV-III VLP formation. We elucidated mechanism of the binding of HDV-III HDAg-L to CHC and confirmed the pivotal role of clathrin binding in the assembly of genotype III HDV. CONCLUSIONS: A novel W box which was identified at the C terminus of HDV-III HDAg-L is known to differ from the conventional clathrin box but also interacts with CHC. The novel W box of HDAg-L constitutes a new molecular target for anti-HDV-III therapeutics.

Bisdemethoxycurcumin suppresses human brain glioblastoma multiforme GBM 8401 cell migration and invasion via affecting NF-κB and MMP-2 and MMP-9 signaling pathway in vitro.

Human glioblastoma (GBM) is one of the common cancer death in adults worldwide, and its metastasis will lead to difficult treatment. Finding compounds for future to develop treatment is urgent. Bisdemethoxycurcumin (BDMC), a natural product, was isolated from the rhizome of turmeric (Curcuma longa), which has been shown to against many human cancer cells. In the present study, we evaluated the antimetastasis activity of BDMC in human GBM cells. Cell proliferation, cell viability, cellular uptake, wound healing, migration and invasion, and western blotting were analyzed. Results indicated that BDMC at 1.5-3 µM significantly decreased the cell proliferation by MTT assay. BDMC showed the highest uptake by cells at 3 h. After treatment of BDMC at 12-48 h significantly inhibited cell motility in GBM 8401 cells by wound healing assay. BDMC suppressed cell migration and invasion at 24 and 48 h treatment by transwell chamber assay. BDMC significantly decreased the levels of proteins associated with PI3K/Akt, Ras/MEK/ERK pathways and resulted in the decrease in the expressions of NF-κB, MMP-2, MMP-9, and N-cadherin, leading to the inhibition of cell migration and invasion. These findings suggest that BDMC may be a potential candidate for the antimetastasis of human GBM cells in the future.

Calreticulin Regulates ß1-Integrin mRNA Stability in PC-3 Prostate Cancer Cells.

Prostate cancer (PCa) is the major cause of cancer-related death among aging men worldwide. Recent studies have suggested that calreticulin (CRT), a multifunctional chaperon protein, may play an important role in the regulation of PCa tumorigenesis and progression. However, the underlying mechanisms are still unclear. Integrin is an important regulator of cancer metastasis. Our previous study demonstrated that in J82 bladder cancer cells, CRT affects integrin activity through FUBP-1-FUT-1-dependent fucosylation, rather than directly affecting the expression of ß1-integrin itself. However, whether this regulatory mechanism is conserved among different cell types remains to be determined. Herein, we attempted to determine the effects of CRT on ß1-integrin in human prostate cancer PC-3 cells. CRT expression was suppressed in PC-3 cells through siRNA treatment, and then the expression levels of FUT-1 and ß1-integrin were monitored through RT-PCR. We found that knockdown of CRT expression in PC-3 cells significantly affected the expression of ß1-integrin itself. In addition, the lower expression level of ß1-integrin was due to affecting the mRNA stability. In contrast, FUT-1 expression level was not affected by knockdown of CRT. These results strongly suggested that CRT regulates cellular behavior differently in different cell types. We further confirmed that CRT directly binds to the 3'UTR of ß1-integrin mRNA by EMSA and therefore affects its stability. The suppression of CRT expression also affects PC-3 cell adhesion to type I collagen substrate. In addition, the levels of total and activated ß1-integrin expressed on cell surface were both significantly suppressed by CRT knockdown. Furthermore, the intracellular distribution of ß1-integrin was also affected by lowering the expression of CRT. This change in distribution is not lysosomal nor proteosomal pathway-dependent. The treatment of fucosydase significantly affected the activation of surface ß1-integrin, which is conserved among different cell types. These results suggested that CRT affects the expression of ß1-integrin through distinct regulatory mechanisms.

Expression levels of caspase-3 and gasdermin E and their involvement in the occurrence and prognosis of lung cancer.

BACKGROUND: Pyroptosis plays a dual role in the development of cancer and malignancy; as such, it may potentially be a new target for cancer treatment. However, the inflammatory response to pyroptosis may have adverse effects on the body. The roles of gasdermin E (GSDME), caspases, and related proteins associated with pyroptosis in cancer remain controversial. AIM: The goal of this study was to determine whether the expression levels of caspase-3 and GSDME affect the clinical stage, pathological grade, or survival prognosis of patients with lung cancer. METHODS: We examined the protein levels of GSDME, caspase-3, caspase-8, and caspase-9 in lung tissue samples from 100 patients with lung cancer by using immunohistochemistry. RESULTS: We found that GSDME, caspase-3, and caspase-8 were more highly expressed in tumor tissues than in adjacent normal tissues. Moreover, we found that GSDME could serve as a prognostic factor as there was a positive correlation between its expression level and the postoperative survival rate of patients with lung cancer. CONCLUSIONS: GSDME may be an independent factor affecting the prognosis of patients with lung cancer. However, the role of GSDME and its related proteins in cancer requires further research.

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.

Clinicopathological features and prognostic factors associated with gastroenteropancreatic mixed neuroendocrine non-neuroendocrine neoplasms in Chinese patients.

BACKGROUND: The incidence of mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) is low. To improve our understanding of this rare tumor type and optimally guide clinical treatment, associated risk factors, clinical manifestations, and prognosis must be explored. AIM: To identify risk factors that influence the prognosis of patients with gastroenteropancreatic MiNEN (GEP-MiNEN). METHODS: We retrospectively analyzed the clinical data of 46 patients who were diagnosed with GEP-MiNEN at the First Affiliated Hospital of Bengbu Medical College (Anhui, China) between January 2013 and December 2017. Risk factors influencing the prognosis of the patients were assessed using Kaplan-Meier curves and cox regression models. We compared the results with 55 randomly selected patients with gastroenteropancreatic GEP neuroendocrine tumors, 47 with neuroendocrine carcinomas (NEC), and 58 with poorly differentiated adenocarcinoma. RESULTS: Among the 46 patients with GEP-MiNEN, thirty-five had gastric tumors, nine had intestinal tumors (four in the small intestine and five in the colon and rectum), and two had pancreatic tumors. The median age of the patients was 66 (41-84) years, and the male-to-female ratio was 2.83. Thirty-three (71.7%) patients had clinical stage III and IV cancers. Distant metastasis occurred in 14 patients, of which 13 had metastasis to the liver. The follow-up period was 11-72 mo, and the median overall survival was 30 mo. Ki-67 index ≥ 50%, high proportion of NEC, lymph node involvement, distant metastasis, and higher clinical stage were independent risk factors affecting the prognosis of patients with GEP-MiNEN. The median overall survival was shorter for patients with NEC than for those with MiNEN (14 mo vs 30 mo, P = 0.001), but did not significantly differ from those with poorly differentiated adenocarcinoma and MiNEN (30 mo vs 18 mo, P = 0.453). CONCLUSION: A poor prognosis is associated with rare, aggressive GEP-MiNEN. Ki-67 index, tumor composition, lymph node involvement, distant metastasis, and clinical stage are important factors for patient prognosis.

Genome-wide CRISPR/Cas9 knockout screening uncovers a novel inflammatory pathway critical for resistance to arginine-deprivation therapy.

Arginine synthesis deficiency due to the suppressed expression of ASS1 (argininosuccinate synthetase 1) represents one of the most frequently occurring metabolic defects of tumor cells. Arginine-deprivation therapy has gained increasing attention in recent years. One challenge of ADI-PEG20 (pegylated ADI) therapy is the development of drug resistance caused by restoration of ASS1 expression and other factors. The goal of this work is to identify novel factors conferring therapy resistance. Methods: Multiple, independently derived ADI-resistant clones including derivatives of breast (MDA-MB-231 and BT-549) and prostate (PC3, CWR22Rv1, and DU145) cancer cells were developed. RNA-seq and RT-PCR were used to identify genes upregulated in the resistant clones. Unbiased genome-wide CRISPR/Cas9 knockout screening was used to identify genes whose absence confers sensitivity to these cells. shRNA and CRISPR/Cas9 knockout as well as overexpression approaches were used to validate the functions of the resistant genes both in vitro and in xenograft models. The signal pathways were verified by western blotting and cytokine release. Results: Based on unbiased CRISPR/Cas9 knockout screening and RNA-seq analyses of independently derived ADI-resistant (ADIR) clones, aberrant activation of the TREM1/CCL2 axis in addition to ASS1 expression was consistently identified as the resistant factors. Unlike ADIR, MDA-MB-231 overexpressing ASS1 cells achieved only moderate ADI resistance both in vitro and in vivo, and overexpression of ASS1 alone does not activate the TREM1/CCL2 axis. These data suggested that upregulation of TREM1 is an independent factor in the development of strong resistance, which is accompanied by activation of the AKT/mTOR/STAT3/CCL2 pathway and contributes to cell survival and overcoming the tumor suppressive effects of ASS1 overexpression. Importantly, knockdown of TREM1 or CCL2 significantly sensitized ADIR toward ADI. Similar results were obtained in BT-549 breast cancer cell line as well as castration-resistant prostate cancer cells. The present study sheds light on the detailed mechanisms of resistance to arginine-deprivation therapy and uncovers novel targets to overcome resistance. Conclusion: We uncovered TREM1/CCL2 activation, in addition to restored ASS1 expression, as a key pathway involved in full ADI-resistance in breast and prostate cancer models.

IGFBP-3 stimulates human osteosarcoma cell migration by upregulating VCAM-1 expression.

AIMS: Insulin-like growth factor (IGF) signaling has been documented in several human malignancies and is thought to contribute to cellular differentiation and migration, as well as malignant progression. A major binding molecule of IGF, IGF-binding protein 3 (IGFBP-3), regulates multiple IGF effects. Here, we focused on the effect of IGFBP-3 in the motility of osteosarcoma cells and examined signaling regulation. MATERIALS AND METHODS: Using a human osteosarcoma tissue array, immunohistochemical staining determined levels of IGFBP-3 expression in osteosarcoma tissue and in normal tissue. The wound healing migration assay, Transwell migration assay, luciferase reporter assay, immunofluorescence staining, Western blot and real-time quantitative PCR were performed to examine whether IGFBP-3 facilitates VCAM-1-dependent migration of osteosarcoma cells. KEY FINDINGS: In this study, we found significantly higher IGFBP-3 levels in osteosarcoma tissue compared with normal healthy tissue. IGFBP-3 treatment of two human osteosarcoma cell lines promoted cell migration and upregulated levels of VCAM-1 expression via PI3K/Akt and AP-1 signaling. SIGNIFICANCE: IGFBP-3 appears to be a novel therapeutic target in metastatic osteosarcoma.

PM2.5 facilitates IL-6 production in human osteoarthritis synovial fibroblasts via ASK1 activation.

Osteoarthritis (OA) is a progressive degenerative joint disorder characterized by synovial inflammation. Interleukin-6 (IL-6) is a key proinflammatory cytokine in OA progression. Particulate matter 2.5 (PM2.5) exposure increases the risk of different diseases, including OA. Up until now, no studies have described any association between PM2.5 and IL-6 expression in human OA synovial fibroblasts (OASFs). Here, our data show that PM2.5 concentration- and time-dependently promoted IL-6 synthesis in human OASFs. We also found that reactive oxygen species (ROS) generation potentiated the effects of PM2.5 on IL-6 production. ASK1, ERK, p38, and JNK inhibitors reduced PM2.5-induced increases of IL-6 expression. Treatment of OASFs with PM2.5 promoted phosphorylation of these signaling cascades. We also found that PM2.5 enhanced c-Jun phosphorylation and its translocation into the nucleus. Thus, PM2.5 increases IL-6 production in human OASFs via the ROS, ASK1, ERK, p38, JNK, and AP-1 signaling pathways. Our evidence links PM2.5 with OA progression.

CXCL13/CXCR5 Interaction Facilitates VCAM-1-Dependent Migration in Human Osteosarcoma.

Osteosarcoma is the most common primary tumor of the skeletal system and is well-known to have an aggressive clinical outcome and high metastatic potential. The chemokine (C-X-C motif) ligand 13 (CXCL13) plays a vital role in the development of several cancers. However, the effect of CXCL13 in the motility of osteosarcoma cells remains uncertain. Here, we found that CXCL13 increases the migration and invasion potential of three osteosarcoma cell lines. In addition, CXCL13 expression was upregulated in migration-prone MG-63 cells. Vascular cell adhesion molecule 1 (VCAM-1) siRNA and antibody demonstrated that CXCL13 promotes migration via increasing VCAM-1 production. We also show that CXCR5 receptor controls CXCL13-mediated VCAM-1 expression and cell migration. Our study identified that CXCL13/CXCR5 axis facilitate VCAM-1 production and cell migration in human osteosarcoma via the phospholipase C beta (PLCß), protein kinase C α (PKCα), c-Src, and nuclear factor-κB (NF-κB) signaling pathways. CXCL13 and CXCR5 appear to be a novel therapeutic target in metastatic osteosarcoma.

Amphiregulin promotes cisplatin chemoresistance by upregulating ABCB1 expression in human chondrosarcoma.

Chondrosarcomas are well known for their resistance to chemotherapeutic agents, including cisplatin, which is commonly used in chondrosarcomas. Amphiregulin (AR), a ligand of epidermal growth factor receptor (EGFR), plays an important role in drug resistance. We therefore sought to determine the role of AR in cisplatin chemoresistance. We found that AR inhibits cisplatin-induced cell apoptosis and promotes ATP-binding cassette subfamily B member 1 (ABCB1) expression, while knockdown of ABCB1 by small interfering RNA (siRNA) reverses these effects. High phosphoinositide 3-kinase (PI3K), Akt and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) phosphorylation levels were observed in cisplatin-resistant cells. Pretreating chondrosarcoma cells with PI3K, Akt and NF-κB inhibitors or transfecting the cells with p85, Akt and p65 siRNAs potentiated cisplatin-induced cytotoxicity. In a mouse xenograft model, knockdown of AR expression in chondrosarcoma cells increased the cytotoxic effects of cisplatin and also decreased tumor volume and weight. These results indicate that AR upregulates ABCB1 expression through the PI3K/Akt/NF-κB signaling pathway and thus contributes to cisplatin resistance in chondrosarcoma.