Progress of research on the surface functionalization of tantalum and porous tantalum in bone tissue engineering.

Tantalum and porous tantalum are ideal materials for making orthopedic implants due to their stable chemical properties and excellent biocompatibility. However, their utilization is still affected by loosening, infection, and peripheral inflammatory reactions, which sometimes ultimately lead to implant removal. An ideal bone implant should have exceptional biological activity, which can improve the surrounding biological microenvironment to enhance bone repair. Recent advances in surface functionalization have produced various strategies for developing compatibility between either of the two materials and their respective microenvironments. This review provides a systematic overview of state-of-the-art strategies for conferring biological functions to tantalum and porous tantalum implants. Furthermore, the review describes methods for preparing active surfaces and different bioactive substances that are used, summarizing their functions. Finally, this review discusses current challenges in the development of optimal bone implant materials.

The role of CXCL2-mediated crosstalk between tumor cells and macrophages in Fusobacterium nucleatum-promoted oral squamous cell carcinoma progression.

Dysbiosis of the oral microbiota is related to chronic inflammation and carcinogenesis. Fusobacterium nucleatum (Fn), a significant component of the oral microbiota, can perturb the immune system and form an inflammatory microenvironment for promoting the occurrence and progression of oral squamous cell carcinoma (OSCC). However, the underlying mechanisms remain elusive. Here, we investigated the impacts of Fn on OSCC cells and the crosstalk between OSCC cells and macrophages. 16 s rDNA sequencing and fluorescence in situ hybridization verified that Fn was notably enriched in clinical OSCC tissues compared to paracancerous tissues. The conditioned medium co-culture model validated that Fn and macrophages exhibited tumor-promoting properties by facilitating OSCC cell proliferation, migration, and invasion. Besides, Fn and OSCC cells can recruit macrophages and facilitate their M2 polarization. This crosstalk between OSCC cells and macrophages was further enhanced by Fn, thereby amplifying this positive feedback loop between them. The production of CXCL2 in response to Fn stimulation was a significant mediator. Suppression of CXCL2 in OSCC cells weakened Fn's promoting effects on OSCC cell proliferation, migration, macrophage recruitment, and M2 polarization. Conversely, knocking down CXCL2 in macrophages reversed the Fn-induced feedback effect of macrophages on the highly invasive phenotype of OSCC cells. Mechanistically, Fn activated the NF-κB pathway in both OSCC cells and macrophages, leading to the upregulation of CXCL2 expression. In addition, the SCC7 subcutaneous tumor-bearing model in C3H mice also substantiated Fn's ability to enhance tumor progression by facilitating cell proliferation, activating NF-κB signaling, up-regulating CXCL2 expression, and inducing M2 macrophage infiltration. However, these effects were reversed by the CXCL2-CXCR2 inhibitor SB225002. In summary, this study suggests that Fn contributes to OSCC progression by promoting tumor cell proliferation, macrophage recruitment, and M2 polarization. Simultaneously, the enhanced CXCL2-mediated crosstalk between OSCC cells and macrophages plays a vital role in the pro-cancer effect of Fn.

Low-dose TNF-α promotes angiogenesis of oral squamous cell carcinoma cells via TNFR2/Akt/mTOR axis.

OBJECTIVES: To assess the role of TNF-α/TNFR2 axis on promoting angiogenesis in oral squamous cell carcinoma (OSCC) cells and uncover the underlying mechanisms. MATERIALS AND METHODS: The expression of TNFR2 and CD31 in OSCC tissues was examined; gene expression relationship between TNF-α/TNFR2 and angiogenic markers or signaling molecules was analyzed; the expression of angiogenic markers, signaling molecules, TNFR1, and TNFR2 in TNF-α-stimulated OSCC cells treated with or without TNFR2 neutralizing antibody (TNFR2 Nab) were assessed; the concentration of angiogenic markers in the supernatant of OSCC cells was detected; conditioned mediums of OSCC cells treated with TNF-α or TNF-α + TNFR2 Nab were applied to human umbilical vein endothelial cells (HUVECs), followed by tube formation and cell migration assays. RESULTS: Significantly elevated expression of TNFR2 and CD31 in OSCC tissues was observed. A positive gene expression correlation was identified between TNF-α/TNFR2 and angiogenic markers or signaling molecules. TNFR2 Nab inhibited the effects of TNF-α on enhancing the expression of angiogenic factors and TNFR2, the phosphorylation of the Akt/mTOR signaling pathway, HUVECs migration, and tube formation. CONCLUSIONS: TNFR2 Nab counteracts the effect of TNF-α on OSCC cells through the TNFR2/Akt/mTOR axis, indicating that blocking TNFR2 might be a promising strategy against cancer.

Pan-cancer spatially resolved single-cell analysis reveals the crosstalk between cancer-associated fibroblasts and tumor microenvironment.

Cancer-associated fibroblasts (CAFs) are a heterogeneous cell population that plays a crucial role in remodeling the tumor microenvironment (TME). Here, through the integrated analysis of spatial and single-cell transcriptomics data across six common cancer types, we identified four distinct functional subgroups of CAFs and described their spatial distribution characteristics. Additionally, the analysis of single-cell RNA sequencing (scRNA-seq) data from three additional common cancer types and two newly generated scRNA-seq datasets of rare cancer types, namely epithelial-myoepithelial carcinoma (EMC) and mucoepidermoid carcinoma (MEC), expanded our understanding of CAF heterogeneity. Cell-cell interaction analysis conducted within the spatial context highlighted the pivotal roles of matrix CAFs (mCAFs) in tumor angiogenesis and inflammatory CAFs (iCAFs) in shaping the immunosuppressive microenvironment. In patients with breast cancer (BRCA) undergoing anti-PD-1 immunotherapy, iCAFs demonstrated heightened capacity in facilitating cancer cell proliferation, promoting epithelial-mesenchymal transition (EMT), and contributing to the establishment of an immunosuppressive microenvironment. Furthermore, a scoring system based on iCAFs showed a significant correlation with immune therapy response in melanoma patients. Lastly, we provided a web interface ( https://chenxisd.shinyapps.io/pancaf/ ) for the research community to investigate CAFs in the context of pan-cancer.

Co-inhibition of adenosine 2b receptor and programmed death-ligand 1 promotes the recruitment and cytotoxicity of natural killer cells in oral squamous cell carcinoma.

Adenosine promotes anti-tumor immune responses by modulating the functions of T-cells and natural killer (NK) cells in the tumor microenvironment; however, the role of adenosine receptors in the progression of oral squamous cell carcinoma (OSCC) and its effects on immune checkpoint therapy remain unclear. In this study, we obtained the tumor tissues from 80 OSCC patients admitted at the Shandong University Qilu Hospital between February 2014 and December 2016. Thereafter, we detected the expression of adenosine 2b receptor (A2BR) and programmed death-ligand 1 (PD-L1) using immunohistochemical staining and analyzed the association between their expression in different regions of the tumor tissues, such as tumor nest, border, and paracancer stroma. To determine the role of A2BR in PD-L1 expression, CAL-27 (an OSCC cell line) was treated with BAY60-6583 (an A2BR agonist), and PD-L1 expression was determined using western blot and flow cytometry. Furthermore, CAL-27 was treated with a nuclear transcription factor-kappa B (NF-κ B) inhibitor, PDTC, to determine whether A2BR regulates PD-L1 expression via the NF-κ B signaling pathway. Additionally, a transwell assay was performed to verify the effect of A2BR and PD-L1 on NK cell recruitment. The results of our study demonstrated that A2BR and PD-L1 are co-expressed in OSCC. Moreover, treatment with BAY60-6583 induced PD-L1 expression in the CAL-27 cells, which was partially reduced in cells pretreated with PDTC, suggesting that A2BR agonists induce PD-L1 expression via the induction of the NF-κ B signaling pathway. Furthermore, high A2BR expression in OSCC was associated with lower infiltration of NK cells. Additionally, our results demonstrated that treatment with MRS-1706 (an A2BR inverse agonist) and/or CD274 (a PD-L1-neutralizing antibody) promoted NK cell recruitment and cytotoxicity against OSCC cells. Altogether, our findings highlight the synergistic effect of co-inhibition of A2BR and PD-L1 in the treatment of OSCC via the modulation of NK cell recruitment and cytotoxicity.

Characteristics of Microbial Distribution in Different Oral Niches of Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC), one of the most common malignant tumors of the head and neck, is closely associated with the presence of oral microbes. However, the microbiomes of different oral niches in OSCC patients and their association with OSCC have not been adequately characterized. In this study, 305 samples were collected from 65 OSCC patients, including tumor tissue, adjacent normal tissue (paracancerous tissue), cancer surface tissue, anatomically matched contralateral normal mucosa, saliva, and tongue coat. 16S ribosomal DNA (16S rDNA) sequencing was used to compare the microbial composition, distribution, and co-occurrence network of different oral niches. The association between the microbiome and the clinical features of OSCC was also characterized. The oral microbiome of OSCC patients showed a regular ecological distribution. Tumor and paracancerous tissues were more microbially diverse than other oral niches. Cancer surface, contralateral normal mucosa, saliva, and tongue coat showed similar microbial compositions, especially the contralateral normal mucosa and saliva. Periodontitis-associated bacteria of the genera Fusobacterium, Prevotella, Porphyromonas, Campylobacter, and Aggregatibacter, and anaerobic bacteria were enriched in tumor samples. The microbiome was highly correlated with tumor clinicopathological features, with several genera (Lautropia, Asteroleplasma, Parvimonas, Peptostreptococcus, Pyramidobacter, Roseburia, and Propionibacterium) demonstrating a relatively high diagnostic power for OSCC metastasis, potentially providing an indicator for the development of OSCC.

M1 Macrophages Enhance Survival and Invasion of Oral Squamous Cell Carcinoma by Inducing GDF15-Mediated ErbB2 Phosphorylation.

M2 macrophages are generally recognized to have a protumor role, while the effect of M1 macrophages in cancer is controversial. Here, the in vitro and in vivo effects of conditioned medium from M1 macrophages (M1-CM) on oral squamous cell carcinoma (OSCC) cells and a potential mechanism were studied. CCK-8, colony formation, EdU labeling, xenograft growth, and Transwell assays were utilized to observe cell survival/proliferation and migration/invasion, respectively, in OSCC cell lines treated with basic medium (BM) and M1-CM. The ErbB2 phosphorylation inhibitor (CI-1033) and GDF15 knockout cell lines were used to appraise the role of ErbB2 and GDF15 in mediating the effects of M1-CM. Compared with BM, M1-CM significantly enhanced the survival/proliferation of SCC25 cells. The migration/invasion of SCC25 and CAL27 cells also increased. Mechanically, M1-CM promoted GDF15 expression and increased the phosphorylation of ErbB2, AKT, and ErK. CI-1033 significantly declined the M1-CM-induced activation of p-AKT and p-ErK and its protumor effects. M1-CM stimulated enhancement of p-ErbB2 expression was significantly decreased in cells with GDF15 gene knockout vs without. In xenograft, M1-CM pretreatment significantly promoted the carcinogenic potential of OSCC cells. Our results demonstrate that M1 macrophages induce the proliferation, migration, invasion, and xenograft development of OSCC cells. Mechanistically, this protumor effect of M1 macrophages is partly associated with inducing GDF15-mediated ErbB2 phosphorylation.

Progranulin inhibits LPS-induced macrophage M1 polarization via NF-кB and MAPK pathways.

BACKGROUND: Macrophage M1 polarization plays a pivotal role in inflammatory diseases. Progranulin (PGRN) has potential anti-inflammation action, however, the effect of PGRN on macrophage M1 polarization has been poorly studied. Our study aimed to investigate the effect of PGRN on lipopolysaccharide (LPS)-induced macrophage M1 polarization and clarify the underlying mechanisms. METHODS: RAW264.7 cells were polarized to M1 macrophage by LPS with or without recombinant PGRN (rPGRN) and tumor necrosis factor alpha antibody (anti-TNF-α). A cell counting kit-8 assay (CCK-8), flow cytometry, Quantitative Real-Time PCR assay (q-PCR), Western blot assay and enzyme-linked immunosorbent assay (ELISA) were used to determine the effect of different treatments on cell proliferation, expression of surface phenotype marker and expressions and secretion of inflammatory cytokines. The activation of NF-κB/mitogen-activated protein kinase (MAPK) pathways and the nuclear translocation of NF-κB p65 were detected by Western blot and immunofluorescence respectively. THP-1 and primary bone marrow-derived monocytes (BMDMs) were also used to demonstrate effect of PGRN on expressions and secretion of inflammatory cytokines induced by LPS. RESULTS: In RAW264.7 cells, rPGRN at concentrations below 80 ng/ml significantly promoted cell proliferation in dose dependent fashion. rPGRN significantly inhibited LPS-induced change of phenotype (CD86/CD206 ratio) and function (tumor necrosis factor (TNF-α) and inducible nitric oxide synthase (iNOS) expressions). LPS-stimulated secretion of TNF-α and activated phosphorylation of IKKα/ß, IкBα, p65, JNK and p38 and the nucleus translocation of NF-кB p65 were also significantly downregulated by rPGRN. In addition, recombinant TNF-α (rTNF-α) significantly boosted TNF-α and iNOS expression vs the control group. Moreover, anti-TNF-α significantly inhibited LPS-induced TNF-α and iNOS expression. In THP-1 and BMDM cells, reversing effect of rPGRN on LPS-enhanced expressions of TNF-α and iNOS and secretion of TNF-α was further demonstrated. CONCLUSIONS: PGRN down-regulates LPS-induced macrophage M1 polarization in phenotype and function via NF-κB/MAPK signaling pathways.

EphB4/ TNFR2/ERK/MAPK signaling pathway comprises a signaling axis to mediate the positive effect of TNF-α on osteogenic differentiation.

BACKGROUND: Low concentrations of tumor necrosis factor-alpha (TNF-α) and its receptor TNFR2 are both reported to promote osteogenic differentiation of osteoblast precursor cells. Moreover, low concentrations of TNF-α up-regulate the expression of EphB4. However, the molecular mechanisms underlying TNF-α-induced osteogenic differentiation and the roles of TNFR2 and EphB4 have not been fully elucidated. RESULTS: The ALP activity, as well as the mRNA and protein levels of RUNX2, BSP, EphB4 and TNFR2, was significantly elevated in MC3T3-E1 murine osteoblast precursor cells when stimulated with 0.5 ng/ml TNF-α. After TNFR2 was inhibited by gene knockdown with lentivirus-mediated shRNA interference or by a neutralizing antibody against TNFR2, the pro-osteogenic effect of TNF-α was partly reversed, while the up-regulation of EphB4 by TNF-α remained unchanged. With EphB4 forward signaling suppressed by a potent inhibitor of EphB4 auto-phosphorylation, NVP-BHG712, TNF-α-enhanced expressions of TNFR2, BSP and Runx2 were significantly decreased. Further investigation into the signaling pathways revealed that TNF-α significantly increased levels of p-JNK, p-ERK and p-p38. However, only the p-ERK level was significantly inhibited in TNFR2-knockdown cells. In addition, the ERK pathway inhibitor, U0126 (10 µM), significantly reversed the positive effect of TNF-α on the protein levels of RUNX2 and BSP. CONCLUSIONS: The EphB4, TNFR2 and ERK/MAPK signaling pathway comprises a signaling axis to mediate the positive effect of TNF-α on osteogenic differentiation.

Curcumin suppresses the proliferation and tumorigenicity of Cal27 by modulating cancer-associated fibroblasts of TSCC.

Cancer-associated fibroblasts (CAFs) are "activated" fibroblasts in the tumor microenvironment (TME) and play a vital role in all steps of cancer development. Increasing evidence focusing on the function of CAFs suggests that CAFs are candidate therapeutic targets and that drugs targeting the modification of CAFs would suppress tumor progression and be beneficial to tumor treatment and prevention. In the present study, we found that curcumin reversed the phenotype of CAFs to that of peri-tumor fibroblast (PTF)-like cells by downregulating the expression of α-SMA (a special marker for CAFs) and inhibiting the secretion of pro-carcinogenic cytokines, including transforming growth factor-ß1 (TGF-ß1), matrix metalloproteinases 2 (MMP2), and stromal cell-derived factor-1 (SDF-1). We further demonstrated that the conditioned medium (CM) derived from CAFs promoted the proliferation of Cal27, and this effect was confirmed by the xenograft model. More importantly, we found that curcumin blocked the CAF-mediated enhancement of Cal27 proliferation in vitro and in vivo. In conclusion, our data suggest that curcumin reverses cell phenotype from CAF to PTF-like cells and suppresses the CAF-mediated proliferation and tumorigenicity of Cal27 by inhibiting TSCC CAFs.

Conditioned medium derived from FGF-2-modified GMSCs enhances migration and angiogenesis of human umbilical vein endothelial cells.

BACKGROUND: Angiogenesis plays an important role in tissue repair and regeneration, and conditioned medium (CM) derived from mesenchymal stem cells (MSC-CM) possesses pro-angiogenesis. Nevertheless, the profile and concentration of growth factors in MSC-CM remain to be optimized. Fibroblast growth factor-2 (FGF-2) has been proven to be an effective angiogenic factor. Thus, the aim of this study was to verify whether FGF-2 gene overexpression optimized CM from human gingival mesenchymal stem cells (hGMSCs) and whether such optimized CM possessed more favorable pro-angiogenesis effect. METHODS: First, FGF-2 gene-modified hGMSCs were constructed using lentiviral transfection technology (LV-FGF-2+-hGMSCs) and the concentration of angiogenesis-related factors in LV-FGF-2+-hGMSC-CM was determined by ELISA. Then, human umbilical vein endothelial cells (HUVECs) were co-cultured for 3 days with LV-FGF-2+-hGMSC-CM, and the expression level of placenta growth factor (PLGF), stem cell factor (SCF), vascular endothelial growth factor receptor 2 (VEGFR2) in HUVECs were determined by qRT-PCR, western blot, and cellular immunofluorescence techniques. The migration assay using transwell and in vitro tube formation experiments on matrigel matrix was conducted to determine the chemotaxis and angiogenesis enhanced by LV-FGF-2+-hGMSC-CM. Finally, NOD-SCID mice were injected with matrigel mixed LV-FGF-2+-hGMSC-CM, and the plug sections were analyzed by immunohistochemistry staining with anti-human CD31 antibody. RESULTS: LV-FGF-2+-hGMSC-CM contained significantly more FGF-2, vascular endothelial growth factor A (VEGF-A), and transforming growth factor ß (TGF-ß) than hGMSC-CM. HUVECs pretreated with LV-FGF-2+-hGMSC-CM expressed significantly more PLGF, SCF, and VEGFR2 at gene and protein level than hGMSC-CM pretreated HUVECs. Compared with hGMSC-CM, LV-FGF-2+-hGMSC-CM presented significantly stronger chemotaxis to HUVECs and significantly strengthened HUVECs mediated in vitro tube formation ability. In vivo, LV-FGF-2+-hGMSC-CM also possessed stronger promoting angiogenesis ability than hGMSC-CM. CONCLUSIONS: Overexpression of FGF-2 gene promotes hGMSCs paracrine of angiogenesis-related growth factors, thereby obtaining an optimized conditioned medium for angiogenesis promotion.

Progranulin promotes osteogenic differentiation of human periodontal ligament stem cells via tumor necrosis factor receptors to inhibit TNF-α sensitized NF-kB and activate ERK/JNK signaling.

OBJECTIVE: To investigate the molecular mechanism of Progranulin (PGRN) in promoting osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) in inflammatory environment. BACKGROUND: Progranulin is an antagonist of tumor necrosis factor (TNF) receptors (TNFRs) and is known to promote inflammatory periodontal bone defect regeneration. METHODS: TNFR1- and TNFR2-silenced hPDLSCs designed as hPDLSCs-sh-TNFR1 and hPDLSCs-sh-TNFR2 were cultured with osteoinductive medium containing TNF-α and (or) PGRN. Immunofluorescence, quantitative real-time PCR, and western blot were used to, respectively, detect expressions of TNFR1\TNFR2 and osteogenic differentiation markers as well as phosphorylation level in NF-κB\MAPK-related pathways. RESULTS: Immunofluorescence and real-time PCR showed that TNFR1 and TNFR2 positively expressed in hPDLSCs. TNF-α stimulation could significantly decrease the expressions of ALP and RUNX2 in hPDLSCs, whereas PGRN treatment could significantly enhance their expressions, and reverse TNF-α-mediated expression suppression of ALP and RUNX2 in hPDLSCs. In hPDLSCs-sh-TNFR1, TNF-α mediated osteogenic inhibition decreased, but both TNF-α + PGRN and alone PGRN significantly promoted expression of ALP and RUNX2. PGRN significantly enhanced expression of P-ERK1/2 and P-JNK, while corresponding inhibitors eliminated PGRN-stimulated osteogenic differentiation. In hPDLSCs-sh-TNFR2, no significant difference existed in osteogenic markers and P-JNK expression between the PGRN group and the control group. However, PGRN still activated P-ERK1/2 expression. Besides, PGRN antagonized TNF-α-enhanced NF-κB P65 expression. CONCLUSION: Progranulin promotes osteogenic differentiation of hPDLSCs via TNFR1 to inhibit TNF-α-sensitized NF-κB and via TNFR2 to activate JNK signaling. The mechanism by which PGRN activates ERK signaling remains to be explored.

Cancer associated fibroblasts are distinguishable from peri-tumor fibroblasts by biological characteristics in TSCC.

The aim of the present study was to investigate the differential biological characteristics between cancer-associated fibroblasts (CAFs) and peri-tumor fibroblasts (PTFs) in tongue squamous cell carcinoma (TSCC). The primary CAFs and PTFs from TSCC were obtained and purified. Cell morphology was observed, and the expression of α-smooth muscle actin (α-SMA), vimentin and cytokeratin 19 (CK19) was detected by immunohistochemistry (IHC). The percentage of α-SMA positive cells in CAFs and PTFs was calculated separately, and α-SMA expression was further confirmed by western blot analysis. Cell viability and the expression of matrix metalloproteinase 2 (MMP2), stromal cell derived factor1 (SDF-1) and transforming growth factor ß1 (TGFß1) in the purified fibroblasts was detected separately. CAFs and PTFs were attained and purified. Compared with PTFs, CAFs were long-fusiform shaped cells with reduced cytoplasm and variable size. CAFs crowded together in a disorderly manner when the cell density was increased, but this phenomenon did not occur with PTFs. IHC results verified that there was no significant difference between CAFs and PTFs in the percentage of cells staining positive for CK19 and vimentin (P>0.05); the percentage of positive staining cells for α-SMA in CAFs was significantly higher compared with that in PTFs (P<0.001) Western blot analysis showed that α-SMA expression in CAFs was 4.3-fold higher compared with that in PTFs (P<0.001). A Cell Counting Kit-8 assay indicated that the viability of CAFs increased significantly compared with that in the PTFs (P<0.05). Reverse transcription-quantitative polymerase chain reaction and ELISA analysis showed that the expression of MMP2, SDF-1 and TGF ß1 in CAFs was higher compared with that in PTFs (P<0.05). CAFs are distinguishable from PTFs with respect to their morphology, cellular phenotype, cell viability and pro-carcinogenic cytokine expression.

The growth inhibitory effect of human gingiva-derived mesenchymal stromal cells expressing interferon-ß on tongue squamous cell carcinoma cells and xenograft model.

BACKGROUND: Interferon-ß (IFN-ß) is a cytokine with pleiotropic cellular functions, including antiviral, antiproliferative, and immunomodulatory activities. IFN-ß inhibits multiple tumor cell growth in vitro. However, the contradiction between the therapeutic dose of IFN-ß and its maximally tolerated dose is still inextricable in vivo. Human gingiva-derived mesenchymal stromal cells (GMSCs) represent promising vehicles for cancer gene therapy. This study evaluated the potential of GMSCs genetically engineered to produce IFN-ß as a targeted gene delivery system to treat tongue squamous cell carcinoma (TSCC) in vitro and in vivo. METHODS: A lentiviral vector encoding IFN-ß was constructed and transfected into GMSCs to obtain IFN-ß gene-modified GMSCs (GMSCs/IFN-ß). Enzyme-linked immunosorbent assay (ELISA) was used to measure the IFN-ß concentration in conditioned medium (CM) from GMSCs/IFN-ß. The Cell Counting Kit-8 (CCK8), colony formation assay, and flow cytometry were used to detect the effects of GMSCs/IFN-ß on TSCC cell line CAL27 cell growth and apoptosis in vitro. TSCC xenograft model was developed by subcutaneous injection of CAL27 cells into BALB/c nude mouse, and the role of intravenously injected GMSCs/IFN-ß in engrafting in TSCC and controlling tumor progression was measured in vivo. RESULTS: GMSCs/IFN-ß expressed a high level of IFN-ß. Both CCK8 and colony forming assay showed that GMSCs/IFN-ß significantly inhibited the proliferation of CAL27 cells compared with the GMSCs, GMSCs/vector, or DMEM group. Flow cytometry analysis demonstrated that the CAL27 cell apoptosis rate was higher in the GMSCs/IFN-ß group than in the other three groups. The in vivo experiment revealed that GMSCs/IFN-ß engrafted selectively in TSCC xenograft and expressed a high level of IFN-ß. There were smaller tumor volume and lower number of Ki67-positive cells in the GMSCs/IFN-ß group than in the GMSCs, GMSCs/vector, or phosphate-buffered saline (PBS) group. Interestingly, GMSCs and GMSCs/vector also presented the potential of CAL27 cell growth inhibition in vitro and in vivo, although such an effect was weaker than GMSCs/IFN-ß. CONCLUSIONS: GMSCs/IFN-ß inhibits the proliferation of TSCC cells in vitro and in vivo. These results provide evidence that delivery of IFN-ß by GMSCs may be a promising approach to develop an effective treatment option for TSCC therapy.

The biological behavior optimization of human periodontal ligament stem cells via preconditioning by the combined application of fibroblast growth factor-2 and A83-01 in in vitro culture expansion.

BACKGROUND: As the optimal source of seed cells in periodontal tissue engineering, periodontal ligament stem cells (PDLSCs) have always been researched to improve cell expansion due to their limited resource and spontaneous differentiation in vitro cultivation. Fibroblast growth factor-2 (FGF-2) has been proven to stimulate bone marrow mesenchymal stem cells (BMMSCs) proliferation and maintain their pluripotency when being added to the culture medium. As a small molecule inhibitor of transforming growth factor-beta receptors (TGF-ßRs), A83-01 can also promote cell proliferation. Therefore, the aim of this study was to verify whether the combined application of FGF-2 and A83-01 could augment cell quantity and quality during in vitro culture. METHODS: PDLSCs were preconditioned with A83-01, FGF-2, or their combination. A cell counting kit-8 (CCK8) assay, cell apoptosis assay, ALP activity assay, Alizarin Red S staining assay, RT-PCR assay, Western blot assay and ELISA were used to determine the sustained effects of different preconditioning strategies on the proliferation, apoptosis, stemness, osteogenic differentiation and paracrine action of PDLSCs. RESULTS: The combined application of FGF-2 and A83-01 significantly augmented cell expansion, reduced cell apoptosis, magnified stemness expression, promoted later osteogenic differentiation and mineralization and increased paracrine action of PDLSCs compared with the control. Moreover, the combination presented significant advantages in enhancing proliferation, stemness expression and paracrine action over FGF-2 alone. CONCLUSIONS: The combined application of A83-01 and FGF-2 may be an improved strategy for PDLSCs biological behavior optimization in culture expansion and advantageous for reinforcing proliferation, stemness expression and cytokine secretion over FGF-2 alone.

Effects of insulin-like growth factor binding protein 3 on cell growth and tumorigenesis in oral squamous cell carcinoma.

BACKGROUND: This study was performed to investigate the effect of insulin-like growth factor binding protein 3 (IGFBP3) on the biological behavior of tumor cells and tumorigenesis of oral squamous cell carcinoma (OSCC). METHODS: OSCC HB96, CAL27, and Tca8113 cells were transfected with the following plasmids: siRNA-IGFBP3, pcDNA-0-IGFBP3, or siRNA-NC (negative control). The effect of aberrant IGFBP3 on cell viability, apoptosis, and colony formation was assessed. Quantitative real-time PCR (qRT-PCR) and western blot analysis were used to measure IGFBP3 mRNA and protein levels, respectively. HB96 and CAL27 cells were transfected with IGFBP3-expressing lentiviral plasmids and then transplanted into nude mice to monitor xenograft tumor formation. RESULTS: An optimal transfection efficiency was obtained with 50 pmol siRNA-IGFBP3. Transient silencing of IGFBP3 significantly reduced cell viability, and increased apoptosis in comparison with the non-targeting negative control (NC). Overexpressing IGFBP3 promoted cell viability. Additionally, in comparison with the NC group, both cell growth and colony formation were reduced, while apoptosis was elevated in stably transfected cells. Moreover, silencing IGFBP3 inhibited cell viability and tumor formation in nude mice after 3 weeks, and colony formation, diminished tumorigenesis in nude mice, but promoted cell apoptosis in OSCC cells. CONCLUSIONS: Collectively, our study revealed a protumorigenic role for IGFBP3 in OSCC cancer cells, and demonstrated a potential mechanism for the dysregulation of IGFBP3 in cell growth. Therefore, IGFBP3 may be a potential therapeutic target for the treatment of OSCC.

Progranulin Promotes Regeneration of Inflammatory Periodontal Bone Defect in Rats via Anti-inflammation, Osteoclastogenic Inhibition, and Osteogenic Promotion.

Progranulin (PGRN) has been proved to play a crucial role in anti-inflammation and osteogenesis promotion; thus, it was hypothesized that PGRN could promote bone regeneration in periodontal disease. In this experiment, the periodontal bone defects were established in periodontitis rats; recombinant human progranulin (rhPGRN), tumor necrosis factor alpha inhibitor (anti-TNF-α), or phosphate buffer saline (PBS)-loaded collagen membrane scaffolds were implanted within defects and the rats were sacrificed at scheduled time points. Volume of new bone was assessed by radiological and histomorphometric analyses. Expression of osteogenesis-related markers and tumor necrosis factor-α (TNF-α) was evaluated using immunohistochemistry. Tartrate-resistant acid phosphatase (TRAP) staining was also performed to determine the number of osteoclasts. Immunofluorescence (IF) staining was performed to explore the interaction between rhPGRN and tumor necrosis factor receptors (TNFRs). The results showed that the rhPGRN group had significantly superior quantity and quality of newly formed bone, higher expression of alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2), and TNFR2 compared with the PBS group and the anti-TNF-α group. Similarly to the anti-TNF-α group, the rhPGRN group also exhibited the significant inhibitory effect on the expression of TNF-α and the number of TRAP-positive cells compared with the PBS group. Hence, our experiment suggests that PGRN promotes regeneration of inflammatory periodontal bone defect in rats via anti-inflammation, osteoclastogenic inhibition, and osteogenic promotion. Local administration of PGRN may provide a new therapeutic strategy for periodontal bone regeneration.

Periodontitis May Restrain the Mandibular Bone Healing via Disturbing Osteogenic and Osteoclastic Balance.

Periodontitis has been advocated as a systematic chronic low-grade infection burden. However, the relationship between periodontitis and bone defect healing has not been elucidated. One hundred and eight male Wister rats were randomly assigned into three groups: control (healthy) group, periodontitis group, and periodontitis plus human tumor necrosis factor receptorII:IgG Fc fusion protein (rhTNFR:Fc) group. The experimental periodontitis model was established by ligaturing with orthodontic wire and silk suture plus local administration of 20 µl of lipopolysaccharide (LPS). Mandibular bone defects in size of 4 × 2 × 1 mm were created for all the rats and rhTNFR:Fc subcutaneously injected at neck at a dose of 2.5 mg/kg every 3 days for the periodontitis plus rhTNFR:Fc group. The gene and protein expressions of bone-related markers in the healing tissue were monitored and new bone formation was histologically evaluated. Tartrate-resistant acid phosphatase (TRAP) staining was performed to determine the number of osteoclasts. The results showed that the mRNA and protein expressions of osteogenesis-related markers were significantly lower while nuclear factor of activated T cells, cytoplasmic 1 (NFATc1) gene expression was significantly higher in the periodontitis group. The periodontitis group showed decreased new bone formation and increased number of osteoclasts when compared to the control group. However, there was no significant difference between the periodontitis plus rhTNFR:Fc group and the control group. These results demonstrated that periodontitis may restrain the mandibular bone healing via disturbing osteogenic and osteoclastic balance in which tumor necrosis factor-α (TNF-α) could act as a leverage.

C-reactive protein is associated with the development of tongue squamous cell carcinoma.

C-reactive protein (CRP) acts as a biomarker reflecting different degrees of inflammation. Accumulating reports have suggested that there is a close relationship between CRP and various cancers. However, the influence of CRP on the development of tongue squamous cell carcinoma (TSCC) remains unclear. The purpose of this study was to investigate the role of CRP in TSCC. The results of immunohistochemical staining and statistical analyses showed that CRP expression was associated with TSCC tumor size, lymph node metastasis and pathological differentiation. Cell Counting Kit-8 (CCK-8) assay revealed that CRP could enhance TSCC cell proliferation in a dose- and time-dependent manner. Moreover, with CRP stimulation, proliferating cell nuclear antigen (PCNA) expression patterns presented a notable time-dependent up-regulation. In addition, CRP could enhance the invasion and migration of TSCC cells, as revealed by transwell and wound-healing assays, respectively. Annexin V-FITC/PI staining showed that CRP could protect TSCC cells from starvation- and drug-induced apoptosis. With CRP stimulation, the protein expression levels of phosphorylated protein kinase B (pAkt), phosphorylated mammalian target of rapamycin (pmTOR) and phosphorylated S6 ribosomal protein (pS6) were significantly increased, as demonstrated by western blot analysis. Our data suggest that CRP may play an important role in the development of TSCC. Moreover, the biological effects of CRP on TSCC cells might be related to Akt, mTOR, and S6.