Vascular Pedicle Ossification After Jaw Reconstruction With Fibular Free Flap.

Ossification of vascular pedicle in free fibular flap for jaw reconstruction was a rare complication. The aim of our study is to evaluate its consequence and propose our clinical experience with surgical management and outcomes of this complication. Our study includes patients who underwent jaw reconstruction with free fibular flap from Jan 2017 to Dec 2021. Patients were included only they had at least one computed tomography scan in follow-up period. Among 112 cases included in our study, 3 cases were observed of abnormal ossification along vascular pedicle who underwent maxilla (two patients) or mandibular (one patient) resection. Two patients who received maxilla resection present a progressive reduction in mouth opening after surgery, and CT scans showed calcified tissue around pedicle. Surgical revision was performed in one patient. Our experience show that periosteum preserves its osteogenic capability which allows the possibility of new bone formation along the vascular pedicle. Another important factor is mechanical stress. From our experience, it was necessary to remove periosteum from vascular pedicle only when mechanical stress of vascular pedicle were high, in order to avoid complication of vascular pedicle calcification. Surgical excision of calcification may be necessary only with clinical symptom. We believe this study could aid in understanding of pedicle ossification and contribute towards prevention and treatment of pedicle ossification.

Multifunctional photodynamic/photothermal nano-agents for the treatment of oral leukoplakia.

Oral leukoplakia (OLK) has gained extensive attention because of the potential risk for malignant transformation. Photosensitizers (PSs) played an indispensable role in the photodynamic therapy (PDT) of OLK, but the poor light sensitivity greatly hampered its clinical application. Herein, a novel organic photosensitive ITIC-Th nanoparticles (ITIC-Th NPs) were developed for OLK photodynamic/photothermal therapy (PTT). ITIC-Th NPs present both high photothermal conversion efficiency (~ 38%) and suitable reactive oxygen species (ROS) generation ability under 660 nm laser irradiation, making them possess excellent PDT and PTT capability. In 4-nitroquinoline 1-oxide (4NQO)-induced oral precancerous animal models, ITIC-Th NPs effectively suppress the OLK's cancerization without apparent topical or systemic toxicity in vivo. This study offers a promising therapeutic strategy for PDT and PTT in OLK treatment, and this study is the first interdisciplinary research in the field of multimodal therapy for OLK.

Thrombus-targeted nano-agents for NIR-II diagnostic fluorescence imaging-guided flap thromboembolism multi-model therapy.

In oral and maxillofacial surgery, flap repair is essential to the quality of postoperative life. Still, thrombosis is fatal for the survival of the flaps. Besides, some postoperative thrombotic diseases, such as pulmonary embolism, also intimidate patients' life. The traditional diagnostic methods are still limited by a large amount of hardware and suffer from inconvenience, delay, and subjectivity. Moreover, the treatments mainly rely upon thrombolytics, such as urokinase (UK) plasminogen activator, which may cause bleeding risk, especially intracerebral hemorrhage. Herein, a kind of poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) containing a first near-infrared window (NIR-I) phototheranostic agent Y8 and urokinase plasminogen activator (UK) as the core, and modified with the fibrin-targeting peptide Gly-Pro-Arg-Pro-Pro (GPRPP) were developed for the flap and postoperative thromboembolism treatment (named GPRPP-Y8U@P). The conjugated molecule Y8 endows GPRPP-Y8U@P with the capacity of NIR-II imaging and excellent photothermal/photodynamic therapeutic effects. In vivo experiments demonstrated that GPRPP-Y8U@P could quickly locate thrombus by NIR-II fluorescence imaging, and semi-quantitative analysis of the embolized blood vessels' paraffin section verified its thrombolytic efficiency. Additionally, the urokinase trapped in the NPs would not result in nonspecific bleeding, tremendously improving physical security and curative effects with minimizing side effects. Overall, the advantages of GPRPP-Y8U@P, such as precise localization of the thrombus, thrombus ablation in the site, and mild side effects, demonstrated the attractiveness of this approach for effective clinical monitoring of thrombus therapy.

The Management of Head and Neck Sarcoma.

OBJECTIVE: To describe the incidence, types, features, treatment and outcomes of head and neck sarcoma managed at a treatment center in eastern China. METHODS: Cases of head and neck soft tissue sarcoma and osteogenic sarcoma treated at the Stomatology Hospital of Nanjing University between 2008 and 2018 were retrospectively analyzed. Patient characteristics, site of lesion, main presenting symptoms, treatment, histology, local recurrence, development of metastatic disease, duration of follow-up and survival rates are described and compared. RESULTS: Sixty-three patients were diagnosed with head or neck sarcoma of which 42.9% had soft tissue sarcoma and 57.1% had osteogenic sarcoma. Of soft tissue sarcoma patients, the most frequently observed histologies were fibrosarcoma and malignant fibrous histiocytoma. Of 36 cases of osteogenic sarcoma, osteosarcoma, and fibrosarcoma of bone were most frequent. Mean latency period between initial symptoms and clinical presentation was 4.5 months. Radical resection was performed on 56 patients. For 33 patients, resection and radiotherapy were used and 10 patients received a triple combination of resection, chemotherapy and radiotherapy. Within the observation period, 17 patients died. CONCLUSIONS: Head and neck sarcomas, although rare, can represent a variety of pathological diagnoses. Surgery remains the main intervention although the data suggest chemotherapy, radical resection and irradiation as treatment. Outcomes are poor with high rates of local recurrence. Positive prognostic factors were tumor-free resection margins and choice of therapy. Due to the rarity of head and neck sarcoma, information remains limited and choice of treatment should be within the focus of clinical multi-center studies.

Large-Scale Identification of Lysine Crotonylation Reveals Its Potential Role in Oral Squamous Cell Carcinoma.

Purpose: Lysine crotonylation, an emerging posttranslational modification, has been implicated in the regulation of diverse biological processes. However, its involvement in oral squamous cell carcinoma (OSCC) remains elusive. This study aims to reveal the global crotonylome in OSCC under hypoxic conditions and explore the potential regulatory mechanism of crotonylation in OSCC. Methods: Liquid-chromatography fractionation, affinity enrichment of crotonylated peptides, and high-resolution mass spectrometry were employed to detect differential crotonylation in CAL27 cells cultured under hypoxia. The obtained data were further subjected to bioinformatics analysis to uncover the involved biological processes and pathways of the dysregulated crotonylated proteins. A site-mutated plasmid was utilized to investigate the effect of crotonylation on Heat Shock Protein 90 Alpha Family Class B Member 1 (HAP90AB1) function. Results: A large-scale crotonylome analysis revealed 1563 crotonylated modification sites on 605 proteins in CAL27 cells under hypoxia. Bioinformatics analysis revealed a significant decrease in histone crotonylation levels, while up-regulated crotonylated proteins were mainly concentrated in non-histone proteins. Notably, glycolysis-related proteins exhibited prominent up-regulation among the identified crotonylated proteins, with HSP90AB1 displaying the most significant changes. Subsequent experimental findings confirmed that mutating lysine 265 of HSP90AB1 into a silent arginine impaired its function in promoting glycolysis. Conclusion: Our study provides insights into the crotonylation modification of proteins in OSCC under hypoxic conditions and elucidates the associated biological processes and pathways. Crotonylation of HSP90AB1 in hypoxic conditions may enhance the glycolysis regulation ability in OSCC, offering novel perspectives on the regulatory mechanism of crotonylation in hypoxic OSCC and potential therapeutic targets for OSCC treatment.

Cholesterol Metabolism Modulation Nanoplatform Improves Photo-Immunotherapeutic Effect in Oral Squamous Cell Carcinoma.

Impressive results in cancer treatment have been obtained through immunotherapy. However, abnormally high cholesterol metabolism in the tumor microenvironment (TME) leads to poor immunogenicity or even immunosuppression, which dramatically reduces the clinical response of patients with oral squamous cell carcinoma (OSCC) to immunotherapy. In this study, a cholesterol-modulating nanoplatform (PYT NP) is developed to restore the normal immune microenvironment, significantly inhibiting SQLE (an essential gene for cholesterol biosynthesis in tumor cells) by releasing terbinafine, thereby reducing cholesterol in the TME and suppressing tumor cell proliferation. In addition, the nanoplatform is equipped with a second near-infrared (NIR-II) photosensitizer, Y8, which triggers immunogenic cell death of tumor cells, thereby promoting intra-tumor infiltration and immune activation via the production of damage-associated molecular patterns for photoimmunotherapy. PYT NPs show great promise in stimulating strong cholesterol-modulating anticancer immunity combined with photoimmunotherapy, opening up a new avenue for sensitized OSCC immunotherapy.

HSP90AB1 Promotes the Proliferation, Migration, and Glycolysis of Head and Neck Squamous Cell Carcinoma.

Background: Head and neck squamous cell carcinoma (HNSCC) is the 6th most common cancer worldwide. Heat shock protein 90 alpha family class B member 1 (HSP90AB1) is highly expressed in a variety of cancers and is associated with poor prognosis, however, its role in HNSCC is still poorly understood. This study aimed to explore the function HSP90AB1 played in HNSCC progression. Methods: The expression level of HSP90AB1 in HNSCC was analyzed by bioinformatics analysis and western blotting, and its relationship with clinicopathological parameters was analyzed by bioinformatics analysis and immunohistochemistry. Three stable HSP90AB1 knockdown HNSCC cell lines were constructed by lentiviral transfection. The effect of HSP90AB1 knockdown on the proliferation and migration of HNSCC cells was tested by CCK-8 assay, EdU incorporation assay, colony formation assay, nude mouse xenograft models, transwell migration assay, wound healing assay, and western blotting. The effect of HSP90AB1 knockdown on glycolysis in HNSCC cells was assessed by quantitative real-time PCR and related assay kits. Finally, the levels of Akt and phospho-Akt (Ser473) proteins after HSP90AB1 knockdown were detected by western blotting. Results: HSP90AB1 was highly expressed in HNSCC and associated with T grade, lymph node metastasis, and prognosis. Knockdown of HSP90AB1 inhibited the proliferation, migration, and glycolysis of HNSCC, and reduced the level of phospho-Akt. Conclusion: HSP90AB1 functions as an oncogene in HNSCC, and has the potential to become a prognostic factor and therapeutic target.

Cancer-associated fibroblasts secrete hypoxia-induced serglycin to promote head and neck squamous cell carcinoma tumor cell growth in vitro and in vivo by activating the Wnt/ß-catenin pathway.

BACKGROUND: The tumor microenvironment (TME) is known to play a prominent role in the pathology of head and neck squamous cell carcinoma (HNSCC). Cancer-associated fibroblasts (CAFs) have been reported to regulate tumor progression, and serglycin (SRGN), one of the paracrine cytokines of CAFs, has been reported to play an important role in various signaling pathways. Hypoxia is a distinct feature of the HNSCC TME. Here, we investigated the mechanism underlying CAF-secreted SRGN leading to HNSCC progression under hypoxia. METHODS: Immunohistochemical staining was used to detect SRGN expression in clinical HNSCC samples, after which its relation with patient survival was assessed. CAFs were isolated and SRGN expression and secretion by CAFs under normoxia and hypoxia were confirmed using qRT-PCR and ELISA assays, respectively. HNSCC sphere-forming abilities, stemness-related gene expression, and chemoresistance were assessed with or without SRGN treatment. A Wnt/ß-catenin pathway inhibitor (PNU-75,654) was used to block its activation, after which nuclear translocation of ß-catenin in the presence of SRGN with or without PNU-75,654 was evaluated. shRNAs were used to stably knock down SRGN expression in CAFs. HNSCC tumor cells with or without (SRGN silenced) CAFs were inoculated submucosally in nude mice after which tumor weights and sizes were determined to assess the effects of CAFs and SRGN on tumor growth. RESULTS: We found that SRGN was expressed in both HNSCC tumor and stroma cells, and that high SRGN expression in the stroma cells, but not in the tumor cells, was significantly related to a poor patient survival. After the extraction of CAFs and normal fibroblasts (NFs) from paired tumor samples and adjacent normal tissues, respectively, we found that the expression of CAF-specific genes, including fibroblast activation protein (FAP) and alpha-smooth muscle actin (α-SMA), was clearly upregulated compared to the expression in NFs. The hypoxia marker HIF-1α was found to be expressed in tumor stroma cells. Hypoxyprobe immunofluorescence staining confirmed stromal hypoxia in an orthotopic tongue cancer mouse model. Using qRT-PCR and ELISA we found that a hypoxic TME upregulated SRGN expression and secretion by CAFs. SRGN markedly enhanced the sphere-forming ability, stemness-related gene expression and chemoresistance of HNSCC tumor cells. SRGN activated the Wnt/ß-catenin pathway and promoted ß-catenin nuclear translocation. An in vivo study confirmed that CAFs can accelerate HNSCC tumor growth, and that this effect can be counteracted by SRGN silencing. CONCLUSIONS: Our data indicate that a hypoxic tumor stroma can lead to upregulation of SRGN expression. SRGN secreted by CAFs can promote ß-catenin nuclear translocation to activate downstream signaling pathways, leading to enhanced HNSCC cell stemness, chemoresistance and accelerated tumor growth.

Co-expression of HIF-1 and TLR3 is associated with poor prognosis in oral squamous cell carcinoma.

This study investigates the prognostic impact of the expression of hypoxia inducible factor (HIF)-1α and Toll-like receptor (TLR) 3 detected by immunohistochemistry in oral squamous cell carcinoma (OSCC). The study also evaluates the treatment outcome by inhibition of the HIF-1α and TLR 3 pathway (nuclear factor [NF]-κB) in an OSCC transplantation model in nude mice. Statistical analysis of immunohistochemical results with clinical findings that included overall survival outcomes was performed for 90 OSCC patients. Forty nude mice were divided into four groups (control; inhibition of HIF-1α; inhibition of NF-κB; and inhibition of HIF-1α and NF-κB). Tumor weight and immunohistochemical results of each group were compared. The results show that co-detection of low HIF-1α/TLR3 expression is significantly correlated with a better prognosis for OSCC patients. Use of an inhibitor of the HIF-1 and TLR3 pathway in an OSCC transplantation model shows a good treatment outcome.

Rh type C-glycoprotein functions as a novel tumor suppressor gene by inhibiting tumorigenicity and metastasis in head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC), a major histologic subtype of head and neck cancer, presents great mortality and morbidity worldwide. The aim of this study is to discover new potential biomarkers closely correlated with HNSCC progression. In this study, weighted gene co-expression network analysis was applied to construct a co-expression network, and the brown module was identified as the most correlated with HNSCC progression. Hub gene identification combined with survival analyses determined RHCG as a candidate biomarker for cancer progression and prognosis prediction. Further experimental results proved that RHCG was aberrantly downregulated in HNSCC tissues and cell lines. Moreover, decreased RHCG expression was shown to be associated with advanced stage and dismal prognosis in HNSCC patients. Functional assays revealed that RHCG could inhibit cell viability, clonogenicity, cell migration in vitro and suppress tumor formation in vivo. Further bioinformatics study demonstrated that DNA promoter hypermethylation of RHCG could lead to its downregulation and serve as potential prognostic maker in HNSCC. Our study reveals that RHCG acts as a tumor suppressor gene that plays a crucial role in inhibiting tumorigenicity and metastasis in HNSCC, which will shed light on the potential diagnostic and therapeutic strategies for HNSCC.

Metformin enhances gefitinib efficacy by interfering with interactions between tumor-associated macrophages and head and neck squamous cell carcinoma cells.

BACKGROUND: Tumor-associated macrophages (TAMs) play an important role in drug resistance in many tumors, including head and neck squamous cell carcinoma (HNSCC). However, how TAMs interact with HNSCC cells to induce drug resistance, especially under hypoxic conditions, is unclear. In this study, we investigated the mechanism of TAM-induced gefitinib resistance in HNSCC cells and sought for novel therapeutic strategies. METHODS: The effects of hypoxia-treated HNSCC cells on the migration and polarization of macrophages were analyzed. Recombinant cytokine proteins and neutralizing antibodies were used as controls. In addition, we assessed the cytotoxic effects of gefitinib on HNSCC cells treated with M2-type macrophage conditioned medium, and carried out a cytokine antibody array analysis, thereby revealing the key factor CCL15. The relationship between serum CCL15 expression levels and prognosis in HNSCC patients was analyzed. In addition, we performed bioinformatic analyses to pursue the mechanisms of CCL15-induced gefitinib resistance. Finally, metformin was used to evaluate the sensitizing effects of gefitinib treatment on HNSCC cells in vitro and in vivo. RESULTS: We found that HNSCC cells recruited macrophages by secreting VEGF and polarized the macrophages to the M2 phenotype through IL-6. Conversely, we found that M2-type TAMs promoted HNSCC cell resistance to gefitinib through paracrine CCL15 signaling. The serum CCL15 levels in HNSCC patients showed a significant correlation with patient prognosis. Furthermore, we found that M2-type TAMs could suppress the sensitivity of HNSCC cells to gefitinib through the CCL15-CCR1-NF-κB pathway. In addition, we found that metformin not only inhibited CCL15 expression in M2-type TAMs enhanced by hypoxia, but also suppressed CCR1 surface expression in HNSCC cells. Encouragingly, we found that metformin sensitized HNSCC cells to gefitinib treatment in vitro and in vivo. CONCLUSIONS: Based on our data we conclude that we have identified a novel interaction between M2-type TAMs and HNSCC cells that contributes to gefitinib resistance. We also found that metformin inhibited the cross-talk between macrophages and tumor cells, thereby eliciting therapeutic effects both in vitro and in vivo.

Accelerated host angiogenesis and immune responses by ion release from mesoporous bioactive glass.

Angiogenesis represents a major focus for novel therapeutic approaches to the treatment and management of multiple pathological conditions, such as ischemic heart disease and critical-sized bone defect. The complex process of angiogenesis begins when cells within a tissue respond to hypoxia by increasing their production of vascular endothelial growth factor (VEGF). Loading biomaterials with angiogenic therapeutics have emerged as a promising approach for developing superior biomaterials for tissue repair and regeneration due to the possibility of reducing treatment costs and side effects when compared to the use of growth factors or genetic engineering approaches. Trace elements, such as copper (Cu), have been reported to be capable of inhibiting prolyl hydroxylases leading to the accumulation and activation of hypoxia-inducible factor-1α (HIF-1α), a major transcription factor regulating the expression of VEGF. It has also recently been speculated that the artifically induced hypoxic microenvironment may regulate the local immune response, which in turn, further facilitates the tissue repair process. The present study has incorporated ionic Cu2+ into mesoporous bioactive glass (MBG), a promising bioactive material system for regenerative medicine, and investigated its effect on angiogenesis and immune responses both in vitro and in vivo. Our results demonstrated that hypoxia-mimicking materials could induce VEGF secretion of bone marrow-derived mesenchymal stromal cells (BMSCs), which provided a positive feedback loop for early blood vessel formation by stimulating migration and tube formation of human umbilical vein endothelial cells (HUVECs). Furthermore, a tissue-regenerative macrophage subtype was triggered by Cu-MBG, leading to superior angiogenic responses (tube formation and angiogenic gene expression) compared to the traditional MBG material. It is concluded that the addition of inorganic ions leads to enhanced angiogenesis and immune responses, which holds promise for the development of functional tissue-engineered constructs to repair and regenerate damaged tissues and organs.

Activation of Macrophages by Lipopolysaccharide for Assessing the Immunomodulatory Property of Biomaterials.

The design paradigm of biomaterials has been changed to ones with favorable immunomodulatory effects, indicating the importance of accurately evaluating the immunomodulatory properties of biomaterials. Among all the immune cells macrophages receive most attention, due to their plasticity and multiple roles in the materials and host interactions, and thereby become model immune cells for the evaluation of immunomodulatory properties of biomaterials in many studies. Lipopolysaccharides (LPS), a polysaccharide in the outer membrane of Gram-negative bacteria, elicit strong immune responses, which was often applied to activate macrophages, resulting in a proinflammatory M1 phenotype, and the release of proinflammatory cytokines, including tumor necrosis factor alpha (TNFα), interleukin (IL)-1, and IL-6. However, there is no consensus on how to apply macrophages and LPS to detect the immunomodulatory properties of biomaterials. The lack of scientific consideration of this issue has led to some inaccurate and insufficient conclusions on the immunomodulatory properties of biomaterials, and inconsistences between different research groups. In this study, we carried out a systemic study to investigate the stimulatory effects of LPS with different times, doses, and conditions on the activation of macrophages. An experimental pathway was proposed accordingly for the activation of macrophages using LPS for assessing the immunomodulatory property of biomaterials.

Nanoporous microstructures mediate osteogenesis by modulating the osteo-immune response of macrophages.

The osteoimmune environment plays indispensable roles in bone regeneration because the early immune environment that exists during the regenerative process promotes the recruitment and differentiation of osteoblastic lineage cells. The response of immune cells growing on nanotopographic surfaces and the microenvironment they generate should be considered when evaluating nanotopography-mediated osteogenesis, which are topics that are generally neglected in the field. In this study, we investigated the modulatory effects of nanoporous anodic alumina with different sized pores on macrophage responses and their subsequent effects on the osteogenic differentiation of bone marrow stromal cells (BMSCs). The nanopore structure and the pore size were found to be important adhesive cues for macrophages, which affected their spreading and cell shape, subsequently regulated the expression and activation of autophagy pathway components (LC3A/B, Beclin-1, Atg3, Atg7, and P62) and modulated the inflammatory response, osteoclastic activities, and release of osteogenic factors. Subsequently, the osteogenic pathways (Wnt and BMP) of BMSCs were found to be regulated by different nanopore-induced inflammatory environments, which affected the osteogenic differentiation outcomes. This study is the first to emphasize the effects of immune cells on nanotopography-mediated osteogenesis, which could lead to a new strategy for the development of advanced nanobiomaterials for tissue engineering, nanomedicine and immunotherapeutic applications.

Tuning Chemistry and Topography of Nanoengineered Surfaces to Manipulate Immune Response for Bone Regeneration Applications.

Osteoimmunomodulation has informed the importance of modulating a favorable osteoimmune environment for successful materials-mediated bone regeneration. Nanotopography is regarded as a valuable strategy for developing advanced bone materials, due to its positive effects on enhancing osteogenic differentiation. In addition to this direct effect on osteoblastic lineage cells, nanotopography also plays a vital role in regulating immune responses, which makes it possible to utilize its immunomodulatory properties to create a favorable osteoimmune environment. Therefore, the aim of this study was to advance the applications of nanotopography with respect to its osteoimmunomodulatory properties, aiming to shed further light on this field. We found that tuning the surface chemistry (amine or acrylic acid) and scale of the nanotopography (16, 38, and 68 nm) significantly modulated the osteoimmune environment, including changes in the expression of inflammatory cytokines, osteoclastic activities, and osteogenic, angiogenic, and fibrogenic factors. The generated osteoimmune environment significantly affected the osteogenic differentiation of bone marrow stromal cells, with carboxyl acid-tailored 68 nm surface nanotopography offering the most promising outcome. This study demonstrated that the osteoimmunomodulation could be manipulated via tuning the chemistry and nanotopography, which implied a valuable strategy to apply a "nanoengineered surface" for the development of advanced bone biomaterials with favorable osteoimmunomodulatory properties.

Europium-doped mesoporous silica nanosphere as an immune-modulating osteogenesis/angiogenesis agent.

Although much research has gone into the design of nanomaterials, inflammatory response still impedes the capacity of nanomaterial-induced tissue regeneration. In-situ incorporation of nutrient elements in silica-based biomaterials has emerged as a new option to endow the nanomaterials modulating biological reactions. In this work, europium-doped mesoporous silica nanospheres (Eu-MSNs) were successfully synthesized via a one-pot method. The nanospheres (size of 280-300 nm) possess uniformly spherical morphology and mesoporous structure, and well distributed Eu elements. The nanospheres show distinct fluorescent property at 615 nm for potential bio-labeling. Noticeably, the Eu-MSNs stimulate pro-inflammatory response of macrophages and induce a modulated immune microenvironment, which further activates the osteogenic differentiation of bone marrow stromal cells (BMSCs) as well as angiogenic activity of human umbilical vein endothelial cells (HUVECs). During the process, osteogenesis-related genes (e.g. ALP, OCN, OPN and COL-I) of BMSCs, and angiogenesis-related genes (e.g. CD31, MMP9, VEGFR1/2, and PDGFRα/ß) of HUVECs were significantly upregulated by Eu-MSNs modulating immune environment of macrophages. The in vivo study further demonstrated that the Eu-MSNs could not only stimulate osteogenesis by accelerating the new bone formation at critical-sized cranial defect site, but also support the blood vessel formation as well as collagen deposition and re-epithelialization at chronic skin wound sites, showing an improved angiogenesis activity when comparing with MSNs alone. Given the easy handling characteristics and extensive application potential, the results suggest that Eu-MSNs could be used as immunity-modulated osteogenesis/angiogenesis agent for skin and bone regeneration.

Crosstalk between the HIF-1 and Toll-like receptor/nuclear factor-κB pathways in the oral squamous cell carcinoma microenvironment.

Hypoxia is a prominent feature of the microenvironment of solid tumors and may contribute to tumor progression through the oxygen-sensitive transcriptional regulator hypoxia-inducible factor-1 (HIF-1). Chronic inflammation is another typical feature. Inflammatory mediators, including Toll-like receptors (TLRs) and nuclear factor-κB (NF-κB), play an important role in cancer development. Recent studies have revealed extensive cross-talk between hypoxia and inflammation signaling, though the mechanisms remain unclear. Our results confirm that TLR3 and TLR4 are highly expressed in oral squamous cell carcinoma (OSCC). Activation of TLR3 and TLR4 stimulated the expression of HIF-1 through NF-κB. In addition, HIF-1 increased the expression of TLR3 and TLR4 through direct promoter binding. Thus, the TLR/NF-κB pathway forms a positive feedback loop with HIF-1. These results indicate a novel cross-talk between the TLR/NF-κB and HIF-1 signaling, which may contribute to OSCC initiation and progression. With the elucidation of this novel mechanism, it might serve as a basis for future microenvironment targeted cancer therapy.

Metformin sensitizes the response of oral squamous cell carcinoma to cisplatin treatment through inhibition of NF-κB/HIF-1α signal axis.

Resistance towards chemotherapy is a common complication in treatment of oral cancers, which leads to treatment failure and poor outcome. In recent years, a growing body of evidence has shown that tumour hypoxia significantly contributes to chemoresistance. Metformin, a widely used oral hypoglycaemic drug, can reportedly potentiate the efficacy of chemotherapeutic drugs in various cancers; however, the underlying mechanisms are intricate and have not been fully understood. In this study, we explored the role of metformin in chemosensitivity of oral squamous cell carcinoma cells (OSCC) to cisplatin both in vitro and in vivo, and attempted to elucidate its possible underlying mechanisms. Encouragingly, we found that metformin synergistically enhanced cisplatin cytotoxicity and reversed the chemoresistance to certain extent. This mechanism could likely be related with inhibition of the NF-κB/HIF-1α signal axis and lead to the downregulation of hypoxia-regulated genes products. Therefore, metformin could serve as a chemosensitiser for cisplatin-based regimens for OSCC, thereby providing a theoretical basis for future use in the treatment of oral cancers.

[Establishment of CoCl2 induced hypoxic cell model of oral squamous cell carcinoma and a preliminary study on the biological behaviour change].

OBJECTIVE: To mimic oral squamous cell carcinoma (OSCC) cell hypoxia by using chemical agent CoCl2 and to investigate its biological behaviour. METHODS: Oral squamous cell carcinoma cell lines HSC-3 and SCC-4 were exposed to different concentration of CoCl2. HSC-3 and SCC-4 cells were treated with 50, 100, 150, 200 µmol/L CoCl2. Expression of hypoxia inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF) and B-cell lymphoma-2 (BCL-2) were measured by real time polymerase chain reaction (PCR) and Western blotting in both mRNA and protein level. Cell proliferation, cell apoptosis and cell cycle were detected to analyze its biological behaviour. Both wound healing and Transwell assay were applied to test the ability of cell igration. RESULTS: The result showed that after treatment of 150 µmol/L CoCl2 for 24 h, mRNA level of HIF-1α, VEGF and Bcl-2 was increased by 6.00 ± 0.20, 5.40 ± 0.40, 5.40 ± 0.30 (SCC-4); 5.60 ± 0.30, 5.20 ± 0.60, 5.80 ± 0.40(HSC-3). OSCC cells treated with 150 µmol/L CoCl2 for 24 h were collected. Compared with control group, the growth rate of cells was significantly decreased, P value was less than 0.05 (when HSC-3, SCC-4 cultured for 2 and 3 days). The apoptosis of OSCC cells was increased when treated with 150 µmol/L CoCl2 for 24 h:HSC-3 2.25% (control group) and 5.82% (treatment group); SCC-4 2.58% (control group) and 10.27% (treatment group). The migration ablility of OSCC cells was decreased when using 150 µmol/L CoCl2 for 24 h. The migration area ratio was (31.5 ± 2.3) % (HSC-3), (29.1 ± 1.5) % (SCC-4) in control group and (18.3 ± 1.9) % (HSC-3), (13.2 ± 0.8)% (SCC-4) in treatment group (P < 0.05). CONCLUSIONS: The hypoxic cell model of OSCC could be induced by CoCl2. The expression level of hypoxic markers was up regulated significantly and the cells biological behaviour changed including decreased cell proliferation, increased apoptosis and decreased migration.