Dongmiao Wang

Upregulation of vimentin and aberrant expression of E-cadherin/β-catenin complex in oral squamous cell carcinomas: correlation with the clinicopathological features and patient outcome

Oral squamous cell carcinoma is a challenging oncology problem. A reliable biomarker for metastasis or high-risk prognosis in oral cancer patients remains undefined. Using quantitative immunohistochemistry, we examined the expression of vimentin, E-cadherin, and β-catenin in 83 oral squamous cell carcinoma patients, and the relationships between the expression of these markers and specific clinicopathological features were analysed. The high expression of vimentin was observed in 23 of 43 (53%) tumours from patients who eventually developed a recurrent tumour and was associated with recurrence and death (P<0.001 and <0.001, respectively). The decreased expression of E-cadherin was observed in 36 of 43 (84%) tumours from patients who eventually developed a recurrent tumour and was also associated with recurrence and death (P<0.001 and <0.001, respectively). Although no correlation between β-catenin expression in whole-tumour sections and clinicopathological features was observed, decreased β-catenin expression at the tumour invasive front was closely associated with recurrence and death (P=0.002 and 0.002, respectively). The expression of vimentin and that of E-cadherin were associated with survival and were independent prognostic factors in univariate and multivariate analyses. Our data show that the overexpression of vimentin was closely associated with recurrence and death in oral squamous cell carcinoma patients. The combination of the upregulation of vimentin and aberrant expression of E-cadherin/β-catenin complexes at the tumour invasive front may provide a useful prognostic marker in oral squamous cell carcinoma.

The Hippo transducer TAZ promotes epithelial to mesenchymal transition and cancer stem cell maintenance in oral cancer

The Hippo pathway has emerged as a fundamental regulator in tissue growth, organ size and stem cell functions, and tumorigenesis when deregulated. However, its roles and associated molecular mechanisms underlying oral squamous cell carcinoma (OSCC) initiation and progression remain largely unknown. Here, we identified TAZ, the downstream effector of Hippo signaling, as a novel bona fide oncogene by promoting cell proliferation, migration/invasion and chemoresistance in OSCC. TAZ promoted epithelial‐to‐mesenchymal transition (EMT) and also was involved in TGF‐β1‐induced EMT in oral cancer cells. Furthermore, enriched TAZ sustained self‐renewal, maintenance, tumor‐seeding potential of oral cancer stem cells (CSCs). Remarkably, enforced TAZ overexpression conferred CSCs‐like properties on differentiated non‐CSCs and fueled phenotypic transition from non‐CSCs to CSCs‐like cells. Mechanistically, TAZ‐TEADs binding and subsequent transcriptional activation of EMT mediators and pluripotency factors are presumably responsible for TAZ‐mediated EMT and non‐CSCs‐to‐CSCs conversion. Importantly, aberrant TAZ overexpression was found to be associated with tumor size, pathological grade and cervical lymph node metastasis, as well as unfavorable prognosis. Pharmacological repression of TAZ by simvastatin resulted in potent anti‐cancer effects against OSCC. Taken together, our findings have revealed critical links between TAZ, EMT and CSCs in OSCC initiation and progression, and also established TAZ as a novel cancer biomarker and viable druggable target for OSCC therapeutics.

Tumor-associated macrophages correlate with the clinicopathological features and poor outcomes via inducing epithelial to mesenchymal transition in oral squamous cell carcinoma

BackgroundBoth tumor-associated macrophages (TAMs) and the epithelial to mesenchymal transition (EMT) of cancer cells play key roles in promoting tumor progression. However, whether TAMs could induce EMT in the progression of oral squamous cell carcinoma (OSCC) remains undefined.ResultsHere we detected the expression of macrophages markers CD68 and CD163, epithelial marker E-cadherin and mesenchymal marker vimentin in 127 OSCC patients by using semi-quantitative immunohistochemistry. CD68 and CD163 expression was not confined to the infiltrating TAMs, but also detected in cancer cells. The high number of CD68-positive macrophages was correlated with poor overall survival. Meanwhile, the expression of CD163 both in macrophages and in cancer cells was associated with poor overall survival and had a significant prognostic impact in OSCC. Importantly, the expression of CD163 in cancer cells had a significant relationship with E-cadherin and vimentin. Furthermore, the incubation of TAMs conditioned medium resulted in a fibroblast-like appearance of cancer cells (HN4, HN6 and SCC9) together with the decreased/increased expression of E-cadherin/ vimentin, which were correlated with the enhanced ability of migration and invasion.ConclusionsOur results indicate that TAMs could promote the EMT of cancer cells, thereby leading to the progression of oral cancer.

The histone demethylase LSD1 is a novel oncogene and therapeutic target in oral cancer

The histone demethylase LSD1 functions as a key pro-oncogene and attractive therapeutic target in human cancer. Here we sought to interrogate the oncogenic roles of LSD1 in OSCC tumorigenesis and therapeutic intervention by integrating chemical-induced OSCC model, genetic and pharmacological loss-of-function approaches. Our data revealed that aberrant LSD1 overexpression in OSCC was significantly associated with tumor aggressiveness and shorter overall survival. Increased abundance of LSD1 was detected along with disease progression in DMBA- or 4NQO-induced OSCC animal models. LSD1 depletion via siRNA-mediated knockdown in OSCC cells resulted in impaired cell proliferation, migration/invasion, tumorsphere formation and reduced xenograft growth while inducing cell apoptosis and enhancing chemosensitivity to 5-FU. Moreover, treatments of LSD1 chemical inhibitors (pargyline and tranylcypromine) induced its protein reduction probably via enhanced protein degradation and produced similar phenotypic changes resembling LSD1 silencing in OSCC cells. Pharmacological inhibition of LSD1 by intraperitoneal delivery of these inhibitors resulted in impaired xenograft overgrowth. Taken together, our data reveal the tumorigenic roles of LSD1 and identified LSD1 as a novel biomarker with diagnostic and prognostic significance, and also establish that targeting LSD1 by chemical inhibitors is a viable therapeutic strategy against OSCC.

Perioperative glucocorticosteroid treatment delays early healing of a mandible wound by inhibiting osteogenic differentiation

AIM The purpose of this study is to investigate the effects of dexamethasone on repair of a critical size defect of the mandible in male Sprague-Dawley rats. MATERIALS AND METHODS Fifty rats were divided into 2 groups: saline control and dexamethasone-treated groups. A 1 mm × 3 mm full-thickness bone defect was created at the inferior border of the mandible. Saline or dexamethasone was administered once a day for 5 days after postoperative palinesthesia. On days 1, 3, 6, 10 and 17, after cessation of drug administration, 5 samples from each group were analysed. The bone defect healing process was examined and analysed by stereology, radiology, histology and histochemical staining for total collagen, tartrate-resistant acid phosphatase staining for osteoclasts and immunohistochemical staining for the COX-2, RUNX2 and osteocalcin antigens. RESULTS The dexamethasone-treated rats exhibited significantly lower radiopacity properties compared to the control rats. Histological staining revealed that the osteogenic differentiation and maturation of a callus in the defect region was significantly delayed from day 1 to day 10 in the dexamethasone group after cessation of drug administration compared to the control group. Consistent with the histological data, the level of total collagen protein was significantly lower in the dexamethasone group than in the control group. However, there was no significant difference between the 2 groups at day 17. Immunohistochemical analysis of COX-2, RUNX2 and osteocalcin expression showed that, at day 1, COX-2 and RUNX2 expression in the dexamethasone group was significantly lower than in the control group. There was no significant difference in osteocalcin expression between the two groups at each time point. There was no significant difference in the number of osteoclasts between the two groups. CONCLUSION In a model of bone healing of a mandible defect, dexamethasone-treated rats exhibited impaired osteogenic differentiation and maturation due to the inhibition of COX-2, osteogenic gene, RUNX2 and collagen protein expression, which resulted in delayed bone repair. Although perioperative short-term therapy did not exhibit long-term effects on wound healing of the maxillofacial bone, the application of glucocorticoids should be cautiously considered in the clinic.

Overexpression of miR-29b reduces collagen biosynthesis by inhibiting heat shock protein 47 during skin wound healing

Skin scar formation is characterized by excessive synthesis and aberrant deposition of collagens during wound healing. MicroRNAs are endogenous gene regulators critically involved in diverse biological events including skin scar formation and hold considerable promise as therapeutic targets. However, the detailed molecular mechanisms responsible for collagen production during skin wound repair and scar formation remain incompletely known. Here our data revealed that significant downregulation of miR-29b and upregulation of heat shock protein 47 (HSP47) were observed during wound healing in both excisional and burn wound models and also detected in facial skin scar as compared to adjacent healthy skin. HSP47, a specific chaperon for collagen production and secretion, was identified as a novel and direct post-transcriptional target of miR-29b in skin fibroblasts via bioinformatics prediction and experimental validation. Moreover, the regulatory functions of miR-29b in collagen biosynthesis are partially achieved through modulating HSP47 expression in skin fibroblasts. Furthermore, the profibrotic growth factor TGF-β1 inhibited miR-29b transcription by activating TGF-β/Smads signaling and in turn depressed HSP47 and enhanced collagen 1 production. In contrast, the proinflammatory cytokines IL-1β and TNF-α significantly induced miR-29b transcription via activating NF-κB signaling but had no significant effect on HSP47 and collagen production in skin fibroblasts. Importantly, local delivery of miR-29b lentiviral particles inhibited HSP47 expression and collagen biosynthesis as well as suppressed angiogenesis, thus reducing scar formation in an excisional wound splinting model. Collectively, our data reveal that miR-29b can reduce collagen biosynthesis during skin wound healing likely via post-transcriptional inhibition of HSP47 expression. These findings also suggest that therapeutic targeting of miR-29b/HSP47 might be a viable alternative strategy to prevent or reduce scar formation.

Pharmacological activation of TAZ enhances osteogenic differentiation and bone formation of adipose-derived stem cells

BackgroundAdipose-derived stem cells (ADSCs) are an attractive cell source for bone tissue engineering and have great potential for bone regeneration and defect repair. The transcriptional coactivator with PDZ-binding motif (TAZ) has been demonstrated to modulate osteogenic and adipogenic differentiation of mesenchymal stem cells. However, its roles during ADSC differentiation and therapeutic potentials for bone regeneration have as yet not been well established.MethodsTAZ expression was measured during osteogenic differentiation of ADSCs in vitro. Both loss-of-function and gain-of-function approaches by TAZ knockdown or enforced overexpression were utilized to determine its functions during osteogenic differentiation of ADSCs. TM-25659, a chemical activator of TAZ, was used to determine whether pharmacological activation of TAZ in ADSCs enhanced osteogenic differentiation in vitro and bone formation in animal models. The molecular mechanisms underlying TAZ in promoting osteogenesis of ADSCs were also explored.ResultsIncreased TAZ expression was observed during osteogenic differentiation of human ADSCs. TAZ knockdown resulted in compromised osteogenic differentiation and enhanced adipogenic differentiation of ADSCs. In contrast, enforced TAZ overexpression yielded increased osteogenic differentiation and bone regeneration in vivo, and impaired adipogenic differentiation of ADSCs. Pharmacological activation of TAZ by its chemical activator TM-25659 facilitated osteogenic differentiation of ADSCs. Noticeably, transient treatment of ADSCs with TM-25659 or intraperitoneal injection of TM-25659 significantly enhanced bone regeneration of ADSCs loaded with porous β-TCP in vivo. Mechanistically, TM-25659 exposure significantly promoted TAZ phosphorylation and nuclear translocation, and potentiated the assembly of the TAZ-Runx2 complex. Subsequently, the TAZ-Runx2 complex was further recruited to the promoter of osteocalcin and in turn enhanced its transcription.ConclusionsOur findings indicate that TAZ is a key mediator that promotes ADSC commitment to the osteoblast lineage. Pharmacological activation of TAZ in ADSCs might become a feasible and promising approach to enhance bone regeneration and repair.

Assessment of aging characteristics of female condylar trabecular structure by cone-beam computed tomography

ObjectivesThis study was performed to analyze the aging-related changes of the female condylar bone mineral density (BMD) and trabecular structure by cone-beam computed tomography (CBCT), and determine whether the condylar structure shows obvious changes after menopause.MethodsThe CBCT images of 160 female patients who met the inclusion criteria for the study were collected and divided into four groups by age (20–29 years, 30–39 years, premenopausal, and postmenopausal groups). Computer processing software CT-Analyser (Version 1.15.2.2+; SkyScan, Antwerp, Belgium) was used to measure the condylar BMD and related indexes, namely the bone volume/tissue volume ratio (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular structure model index (SMI), and bone surface area/volume ratio (BS/BV). SPSS 12.0 (SPSS Inc., Chicago, IL, USA) was used to analyze the radiographic findings and statistical differences.ResultsNo significant differences were found between the bilateral condyles in each group (P > 0.05). BV/TV, Tb.N, and Tb.Th of the condyle decreased with age, and the postmenopausal group showed significantly different values for each index compared with the other groups (P < 0.01). Tb.Sp, SMI, and BS/BV of the condyle increased with age, and the postmenopausal group showed significantly different values for each index compared with the other groups (P < 0.01).ConclusionsWith increasing age, the female condylar bone volume decreases, the Tb.N and Tb.Th decrease, the gap between the trabecular bone increases, and plate-like trabecular bone gradually transforms into a rod-like form. These changes are much more obvious in postmenopausal women.

SUZ12 is a novel putative oncogene promoting tumorigenesis in head and neck squamous cell carcinoma

The suppressor of zest 12 (SUZ12), one of the core polycomb repressive complex 2 (PRC2) components, has increasingly appreciated as a key mediator during human tumorigenesis. However, its expression pattern and oncogenic roles in head and neck squamous cell carcinoma (HNSCC) remain largely unexplored yet. Here, we sought to determine its expression pattern, clinicopathological significance and biological roles in HNSCC. Through data mining and interrogation from multiple publicly available databases, our bioinformatics analyses revealed that SUZ12 mRNA was significantly overexpressed in multiple HNSCC patient cohorts. Moreover, SUZ12 protein was markedly up‐regulated in primary HNSCC samples from our patient cohort as assessed by immunohistochemical staining and its overexpression significantly associated with cervical node metastasis and reduced overall and disease‐free survival. In the 4‐nitroquinoline 1‐oxide (4NQO)‐induced HNSCC mouse model, increased SUZ12 immunostaining was observed along with disease progression from epithelial hyperplasia to squamous cell carcinoma in tongue. Furthermore, shRNA‐mediated SUZ12 knock‐down significantly inhibited cell proliferation, migration and invasion in HNSCC cells, and resulted in compromised tumour growth in vivo. Collectively, our data reveal that SUZ12 might serve as a putative oncogene by promoting cell proliferation, migration and invasion, and also a novel biomarker with diagnostic and prognostic significance for HNSCC.

Comprehensive analysis of 225 Castleman’s diseases in the oral maxillofacial and neck region: a rare disease revisited

ObjectivesThe aim of the present study was to comprehensively summarize the epidemiological, clinicopathological characteristics, treatments as well as prognosis of Castleman’s disease (CD) identified in the oral maxillofacial and neck region.Materials and methodsPatients with CD in the oral maxillofacial and neck were retrieved from disease registry at our institution from Jan. 1990 to Dec. 2015. Systematic reviews from both English and Chinese literature were performed to collect the detailed information about the oral maxillofacial and neck CD. The epidemiological, clinicopathological data and treatment outcomes were further statistically analyzed.ResultsFour patients with the oral maxillofacial and neck CD were identified and histologically confirmed as hyaline-vascular type. They underwent surgical excision without recurrence during the follow-up. Systematic literature reviews identified 221 cases from 123 eligible articles which satisfied the inclusion criteria. In 225 patients, most patients were diagnosed as unicentric (207) or hyaline-vascular type (205) of CD and identified in the neck, and treated by surgical resection with good prognosis. In contrast, the minority of patients was multicentric or plasma-cell/mixed type and treated by chemotherapy with inferior outcomes. Kaplan-Meir analyses revealed that both clinical and pathological types were significantly associated with patients’ overall survival.ConclusionsAlthough rare, most cases of the oral maxillofacial neck CD are found in adults and classified as unicentric and hyaline-vascular type of CD. Complete surgical excision is preferred with favorable prognosis for unicentric disease, whereas chemotherapy is usually exploited for multicentric disease with inferior outcomes.Clinical relevanceThese data provide comprehensive information about the epidemiology, clinicopathological features, treatments, and outcomes of the oral maxillofacial and neck CD.