Discovery, Topo I inhibitory activity and mechanism evaluation of two novel cytisine-type alkaloid dimers from the seeds of Sophora alopecuroides L.

Alopecurosines A and B (CMs 1 and 2, respectively) are two novel cytisine-type alkaloid dimers first isolated from the aerial parts of Sophora alopecuroides L. CMs 1 and 2 are new dimeric alkaloids whose piperidine matrine ring is cleaved and connected via the N'-1 bond. Their chemical structures have been confirmed by IR, UV, HR-ESI-MS, and NMR. Preliminary screening shows that they have topoisomerase I (Topo I)-based anti-tumor activity. Their Topo I inhibitory activities and mechanism have been evaluated by agarose gel electrophoresis assay and a molecular docking study. The results show that the inhibition rate of CM 1 is 82.26% at 1 mM concentration and that it exhibits significantly Topo I inhibitory activity. Further research has illustrated that CMs 1 and 2 exert inhibitory activity by stabilising the Topo I-DNA cleavage complex, implying that they have the potential to be developed as novel Topo I inhibitors.

The pluripotency factor LIN28B is involved in oral carcinogenesis and associates with tumor aggressiveness and unfavorable prognosis.

OBJECTIVE: LIN28B is a conserved RNA-binding protein critically involved in development, cellular metabolism and tumorigenesis. It is frequently overexpressed in human cancers and correlates with tumor aggressiveness as well as unfavorable prognosis. However, the expression pattern and oncogenic roles of LIN28B during oral squamous cell carcinoma (OSCC) development and progression has not been well established yet. Here, we sought to determine the expression of LIN28B and its clinical significance using chemical-induced OSCC animal model, cell lines and primary specimens. METHOD: The OSCC animal model was induced using 7,12-dimethyl-1,2-bezan-tracene (DMBA) painting in the hamster buccal pouch. Buccal lesions from animals were obtained from different time points and subjected to routine histological analyses and immunohistochemical staining of LIN28B. The mRNA, protein abundance and subcellular localization of LIN28B was determined in a panel of OSCC cell lines by real-time RT-PCR, western blot and immunofluorescence. The expression levels of LIN28B in human primary OSCC samples were further evaluated by immunohistochemical staining. Moreover, the relationship between LIN28B and several clinicopathological parameters as well as patients' prognosis were also assessed. RESULTS: Our results revealed that negative or low LIN28B expression was commonly observed in normal epithelial, whereas more LIN28B abundance was identified in epithelial dysplasia and invasive SCC in the DMBA-induced OSCC animal model. Overexpression of LIN28B was identified in a major fraction of OSCC samples(39/58) and significantly associated with tumor size (P = 0.049) and advanced clinical stages (P = 0.0286). Patients with increased LIN28B had markedly reduced overall survival as compared to those with low LIN28B. Multivariate survival analyses further indicated that LIN28B abundance served as an independent prognostic factor for patients' overall survival. CONCLUSIONS: Our findings reveal that LIN28B is critically involved in OSCC initiation and progression and aberrantly overexpressed in human OSCC. It might represent a novel diagnostic and prognostic biomarker for oral cancer.

High expression of the histone demethylase LSD1 associates with cancer cell proliferation and unfavorable prognosis in tongue cancer.

BACKGROUND: The histone lysine-specific demethylase (LSD1) is a key chromatin modifier mediating the demethylation of both H3K4me1/me2 and H3K9 me1/me2. Recently, its deregulation has been implicated in the initiation and progression of various cancers. The aim of this study was to investigate the expression pattern of LSD1 in tongue squamous cell carcinoma (SCC) and determine its prognostic significance in predicting patients' prognosis. METHODS: LSD1 expression was examined by RT-PCR and western blotting in three tongue cancer cell lines and by immunohistochemistry in 63 primary tongue SCC specimens with detailed clinical, pathological, and follow-up data. Its associations with various clinicopathological parameters, Ki-67 expression, and patients' survival were further assessed. RESULTS: Upregulated LSD1 expression was observed in tongue cancer cells and a major fraction of tongue SCC samples. Overexpression of LSD1 significantly associated with tumor size (P = 0.0357), pathological grade (P = 0.0323), Ki-67 abundance (P = 0.0148), and reduced overall and disease-free survival (Kaplan-Meier analysis, P = 0.0351, 0.0479, respectively). The Cox regression survival analyses identified LSD1 as an important independent predictor for patients' overall survival. CONCLUSION: Our data indicate that aberrant LSD1 overexpression associates with key clinicopathological features and unfavorable prognosis in patients with tongue cancer. LSD1 might play critical roles during tongue tumorigenesis and represent a novel biomarker and potential therapeutic target for this malignancy.

Oncogenic roles of Bmi1 and its therapeutic inhibition by histone deacetylase inhibitor in tongue cancer.

The polycomb complex protein Bmi1 (B lymphoma Mo-MLV insertion region 1 homolog) mediates epigenetic transcriptional silencing by modifying chromatin structure and is critical for stem cell homeostasis and tumorigenesis. Bmi1 is frequently overexpressed in human malignancies and therefore has key diagnostic and prognostic significance, and holds potential as a therapeutic target. Here we sought to characterize the expression patterns and oncogenic roles of Bmi1 in tongue squamous cell carcinoma and to determine the anticancer effects of histone deacetylase inhibitors (HDACis) via Bmi1 inhibition against tongue cancer. Our data revealed that Bmi1 was aberrantly overexpressed in a significant portion of tongue cancers. Elevated Bmi1 is associated with cervical node metastasis, Ki-67 abundance and reduced overall survival, and also serves as an independent prognostic factor for patient outcomes. Short-hairpin RNA-mediated Bmi1 knockdown inhibited cell proliferation and migration, induced cell apoptosis and senescence, reduced colony formation and CD44(+)CD133(+) sub-population as well as enhanced cisplatin chemosensitivity, presumably by modulation of p16, p14 and E-cadherin. Moreover, HDACi chemicals Trichostatin A (TSA) and sodium butyrate (NaB) potently inhibited Bmi1 and triggered similar phenotypic changes reminiscent of Bmi1 silencing, although TSA treatment seemed paradoxically to induce some epithelial-mesenchymal transition-like changes in tongue cancer cells. Importantly, NaB-induced antitumor effects were partially attenuated by enforced Bmi1 overexpression in vitro. Genetic Bmi1 silencing and pharmacological inhibition of Bmi1 by NaB treatment significantly impaired tumor growth in a tongue cancer xenograft model. Taken together, our results indicate that Bmi1 serves as a key driver and biomarker with multiple oncogenic functions underlying tongue tumorigenesis. Selected appropriate HDACi compounds like NaB may represent novel therapeutic agents against tongue cancer.

Overexpression of metabolic markers PKM2 and LDH5 correlates with aggressive clinicopathological features and adverse patient prognosis in tongue cancer.

AIMS: Pyruvate kinase M2 (PKM2) and lactate dehydrogenase 5 (LDH5) are two metabolic and oncogenic markers of cancer. In this study, we sought to investigate their expression patterns and prognostic value in tongue squamous cell carcinoma (TSCC). METHODS AND RESULTS: The expression and subcellular localization of PKM2 and LDH5 in TSCC cell lines were determined by Western blot and immunofluorescence. PKM2 and LDH5 abundance was examined by immunohistochemistry in 63 TSCC tumour specimens; their association with multiple clinicopathological parameters and overall patient survival was assessed. The protein levels of PKM2 and LDH5 were both significantly higher in TSCC cells than in an immortalized oral epithelial cell line. Overexpression of PKM2 associated significantly with cervical node metastasis (P = 0.0373), while elevated LDH5 levels correlated significantly with tumour size (P = 0.0094), pathological grade (P = 0.0052), cervical node metastasis (P = 0.0023) and clinical stage (P = 0.0024). Patients with tumours showing an increase in either PKM2 or LDH5 expression displayed significantly reduced overall survival, while patients with tumours overexpressing both proteins showed the worst prognosis with lowest overall survival. Furthermore, PKM2 and LDH5 were identified as independent prognostic predictors for overall patient survival in TSCC. CONCLUSION: Our data indicate that overexpression of PKM2 and LDH5 associates with key clinicopathological features and unfavourable prognosis in TSCC.

Reconstruction of palatomaxillary defects following cancer ablation with temporalis muscle flap in medically compromised patients: a 15-year single institutional experience.

OBJECTIVES: Successful reconstruction of palatomaxillary defects following cancer ablation represents a formidable challenge for surgeons to achieve consistently favorable outcomes. The purpose of this article is to present our experience in oncologic palatomaxillary repair with temporalis muscle flap (TMF) for medically compromised patients who are not ideal candidates for microvascular reconstruction at a Chinese tertiary referral hospital over a 15-year period (1998-2012). METHOD: A retrospective chart review was performed to identify patients with compromised medical conditions who underwent oncologic palatomaxillary reconstruction using TMF. Patients' demographics, clinicopathological variables, and surgical techniques were presented. Postoperative functional and aesthetic outcomes were assessed by measurements and patients self-evaluations. RESULTS: Sixty-nine TMFs were successfully harvested and used for immediate oncologic palatomaxillary reconstruction in 67 patients (31 males and 36 females, mean age 60.4 years) with diverse primary malignancies. These patients' co-morbidities included systemic diseases, preoperative chemotherapy/radiotherapy, and elder over 65 years which precluded the ideal utility of free flaps. Fifty-one patients remained alive without disease, while nine had recurrences/metastases and seven died during the follow-up (0.5-10.4 years, mean 3.7 years). All flaps survived with only partial necroses in four cases. Complications and donor-site morbidities were minimal with five transient facial paralysis and four mild diplopia and enophthalmos. Unrestricted diet and mouth opening, intelligible speech, and satisfactory temporal aesthetics were obtained in most patients. CONCLUSION: The TMF is a reliable, versatile, and alternative option for oncologic palatomaxillary reconstruction with satisfactory functional and aesthetic outcomes and minimal complications, especially when appropriately selected for those medically compromised patients.

Nanocatalytic theranostics with intracellular mutual promotion for ferroptosis and chemo-photothermal therapy.

The reactive oxygen species (ROS) produced through the Fenton reaction, induces lipid peroxide (LPO), causing cellular structural damage and ultimately triggering ferroptosis. However, the generation of ROS in the tumor microenvironment (TME) is limited by the catalytic efficiency of the Fenton reaction. Herein, a novel hollow mesoporous silica nanoparticle (HMSN) combined with multi-metal sulfide-doped mesoporous silica nanocatalyzers (NCs) was developed, namely MxSy-HMSN NCs (M represents Cu Mn and Fe, S denotes sulfur). The MxSy-HMSN can dramatically enhanced the ferroptosis by: (1) facilitating the conversion of H2O2 to ·OH through Fenton or Fenton-like reactions through co-catalysis; (2) weakening ROS scavenging systems by depleting the over expressed glutathione (GSH) in TME; (3) providing exceptional photothermal therapy to augment ferroptosis. The MxSy-HMSN can also act as smart cargos for anticancer drug-doxorubicin (DOX). The release of DOX is responsive to GSH/pH/Near-infrared Light (NIR) irradiation at the tumor lesion, significantly improving therapeutic outcomes while minimizing side effects. Additionally, the MxSy-HMSN has demonstrated excellent magnetic resonance imaging (MRI) potential. This smart MxSy-HMSN offer a synergetic approach combining ferroptosis with chemo-photothermal therapy and magnetic resonance imaging (MRI) diagnose, which could be an informative guideline for the design of future NCs.

Overexpression of Hippo pathway effector TAZ in tongue squamous cell carcinoma: correlation with clinicopathological features and patients' prognosis.

BACKGROUND: Transcriptional coactivator with PDZ-binding motif (TAZ) is a key downstream effector of Hippo signaling pathway involved in stem cell differentiation and organ development. Recently, its deregulation has been linked to initiation and progression of various cancers. The purpose of this study was to investigate the expression of TAZ in tongue squamous cell carcinoma (TSCC) and its prognostic value in predicting patients' outcomes. METHODS: TAZ expression and localization in a panel of TSCC cell lines and human immortalized oral epithelial cell (HIOEC) were determined by real-time RT-PCR, western blotting, and immunofluorescence. In 52 TSCC tumor specimens with detailed clinical and follow-up data, TAZ abundance was examined by immunohistochemistry and its associations with clinicopathological parameters, Ki-67 expression and patients' survival were further assessed. RESULTS: TAZ mRNA and protein levels were significantly higher in TSCC cells and specimens than those in non-cancerous cells and normal tongue mucosa. Overexpression of TAZ in TSCC was significantly associated with tumor size (P = 0.033), pathological grade (P = 0.026), clinical stage (P = 0.013), Ki-67 expression (P = 0.0485), and reduced overall and disease-free survival (Kaplan-Meier analysis, log-rank test, P = 0.020, 0.019, respectively). Multivariate Cox regression analysis identified TAZ as an important independent predictor for survival of patients with TSCC [HR (hazard ratio), 4.351; 95% CI (95% confidence interval), 1.477-12.819; P = 0.008]. CONCLUSION: Our data indicate that aberrant TAZ overexpression is associated with key clinicopathological features and poor survival in TSCC. These results suggest that TAZ might play critical roles in tumorigenesis of TSCC and become a novel prognostic biomarker and potential therapeutic target for this malignancy.

Biodegradable nanomaterials for diagnosis and therapy of tumors.

Although degradable nanomaterials have been widely designed and applied for cancer bioimaging and various cancer treatments, few reviews of biodegradable nanomaterials have been reported. Herein, we have summarized the representative research advances of biodegradable nanomaterials with respect to the mechanism of degradation and their application in tumor imaging and therapy. First, four kinds of tumor microenvironment (TME) responsive degradation are presented, including pH, glutathione (GSH), hypoxia and matrix metalloproteinase (MMP) responsive degradation. Second, external stimulation degradation is summarized briefly. Next, we have outlined the applications of nanomaterials in bioimaging. Finally, we have focused on some typical examples of biodegradable nanomaterials in radiotherapy (RT), photothermal therapy (PTT), starvation therapy, photodynamic therapy (PDT), chemotherapy, chemodynamic therapy (CDT), sonodynamic therapy (SDT), gene therapy, immunotherapy and combination therapy.

A pH-responsive ZC-QPP hydrogel for synergistic antibacterial and antioxidant treatment to enhance wound healing.

The problems of bacterial resistance and high oxidation level severely limit wound healing. Therefore, we constructed a multifunctional platform of chitosan quaternary ammonium salts (QCS)/polyvinyl alcohol (PVA)/polyethylene glycol (PEG) hydrogels (QPP) loaded with ZnO@CeO2 (ZC-QPP). Firstly, the hydrogel was co-cross-linked by hydrogen and borate ester bonds, which allows easy adherence to a tissue surface for offering a protective barrier and moist environment for wounds. The chitosan quaternary ammonium salts due to their amino groups have inherent antibacterial properties to induce bacterial death. In response to the acidic conditions of the bacterial infection microenvironment, the borate ester bonds in the QPP hydrogel break and the ZC NCs dispersed in the hydrogel are released. The gradual dissociation of Zn2+ under acidic conditions can directly damage bacterial membranes. The wound site of bacterial infection always causes overexpression of reactive oxygen species (ROS) levels, often leading to inflammation and preventing rapid wound repair. CeO2 can eliminate excess ROS to reduce the inflammatory response. From in vitro and in vivo results, the high biosafety of the ZC-QPP hydrogel has demonstrated excellent antibacterial and antioxidant performance to enhance wound healing. Therefore, the ZC-QPP hydrogel opens a method to develop multifunctional synergistic therapeutic platforms combining enzyme-like nanomaterials with hydrogels for synergistic antibacterial and antioxidant treatment to promote wound healing.

Study on the Synthesis and Properties of Waterborne Polyurea Modified by Epoxy Resin.

The most notable features of polyurea are its fast reaction, energy-saving and high efficiency. In order to meet the needs of environmental protection, waterborne polyurea (WPUA) has become a research hotspot. However, the presence of hydrophilic groups in WPUA reduces its solvent resistance, heat resistance and mechanical properties. Therefore, it is necessary and valuable to develop a high-performance WPUA. In this study, epoxy-modified waterborne polyurea (WPUAE) emulsions were prepared using epoxy resin as a modifier. Fourier transform infrared spectroscopy (FT-IR) showed that E44 was successfully introduced into the molecular chain of WPUA. The WPUAE was tested for gel fraction, adhesion, contact angle, solvent resistance, tensile properties and thermal stability. The results showed that when the E44 content was 8 wt%, the performance of WPUAE was best, the adhesion of WPUAE coating film was 1.53 MPa, the gel fraction, water contact angle, water absorption, toluene absorption, tensile strength and decomposition temperature were 96.94%, 70.3°, 16.43%, 131.04%, 9.05 MPa and 365 °C, respectively. The results showed that epoxy resin as an emulsion modifier improved the comprehensive properties of WPUA.

Construction of ultrasound-responsive urokinase precise controlled-release nanoliposome applied for thrombolysis.

Urokinase is widely used in the dissolution of an acute pulmonary embolism due to its high biocatalytic effect. However, how to precisely regulate its dose, avoid the side effects of hemolysis or ineffective thrombolysis caused by too high or too low a dose, and seize the golden time of acute pulmonary embolism are the key factors for its clinical promotion. Therefore, based on the precise design of a molecular structure, an ultrasonic-responsive nanoliposome capsule was prepared in this paper. Singlet oxygen is continuously generated under the interaction of the ultrasonic cavitation effect and the sonosensitizer protoporphyrin, and the generated singlet oxygen will break the thiol acetone bond between the hydrophilic head and the hydrophobic tail of the liposome, and the lipid The body structure disintegrates rapidly, and the urokinase encapsulated inside is rapidly released, down-regulating the expression of fibrinogen in the body, and exerting a thrombolytic function. The in vitro and in vivo results show that the smart urokinase nanoliposomes prepared by us have sensitive and responsive cytocompatibility to ultrasound and good in vivo thrombolytic properties for acute pulmonary embolism, which provides a new strategy for clinical acute pulmonary embolism thrombolysis.

Tumor microenvironment responsive theranostic agent for enhanced chemo/chemodynamic/photothermal therapy.

The specific characteristics of the tumor microenvironment (TME) and monotherapy always lead to poor therapy effects for tumors. Hereby, we have developed a smart multifunctional theranostic agent-SSMID (Se@SiO2@MnO2-ICG/DOX) nanocomposites (NCs) that could intelligently respond to the TME for enhanced chemotherapy/photothermal/chemodynamic therapy guided by magnetic resonance imaging (MRI). The SSMID NCs were composed of indocyanine green (ICG) and doxorubicin hydrochloride (DOX) co-loaded porous Se@SiO2 @MnO2. Under the specific conditions of the TME (slightly acidic, H2O2 and GSH overexpression), the MnO2 NPs were specifically decomposed and then SSMID released Mn2+, DOX and Se, which played roles in chemodynamic therapy (CDT), chemotherapy, protecting normal tissues and inhibiting tumor cells by modulating reactive oxygen species (ROS), respectively. MnO2 reacted with glutathione (GSH) and H2O2 to generate O2 and Mn2+, which alleviated tumor hypoxia to improve chemotherapy and depleted GSH to enhance oxidative stress for chemodynamic therapy. More importantly, SSMID NCs could simultaneously exert the photothermal therapy (PTT) effect with near-infrared laser irradiation and promote the release of Mn2+ and DOX to achieve enhanced chemotherapy/chemodynamic therapy. In addition, the released Mn2+ could be used as a T1-weighted MRI contrast agent to monitor tumor location. The SSMID NCs exhibited a pronounced tumor growth inhibitory effect and promising biological safety, which develop a new method to rationally design nano-theranostic agents with enhanced performance for anti-tumor.

Application of Hydrogels as Carrier in Tumor Therapy: A Review.

Cancer is one of the most intractable diseases in the world because of its high recurrence rate, high metastasis rate and high lethality rate. Traditional chemotherapy, radiotherapy and surgery have unsatisfactory therapeutic effects and cause many severe side effects at the same time. Hydrogel is a new type of biomaterial with the advantages of good biocompatibility and easy degradation, which can be used as a carrier of functional nanomaterials for tumor therapy. Herein, we represent the progress of hydrogels with different skeletons and their application as carrier in tumor treatment. The hydrogels are listed as polyethylene glycol-based hydrogels, chitosan-based hydrogels, peptide-based hydrogels, hyaluronic acid-based hydrogels, steroid-based hydrogels and other hydrogels by skeletons, and their properties, modifications and toxicities were introduced. Some representative applications of combined hydrogels with nanomaterial for chemotherapy, photodynamic therapy, photothermal therapy, sonodynamic therapy, chemodynamic therapy and synergistic therapy are highlighted.

[Non-surgical treatment for nonresectable advanced hepatic alveolar echinococcosis].

OBJECTIVE: To investigate the therapeutic methods of nonresectable advanced hepatic alveolar echinococcosis. METHODS: A retrospective study was carried out to analyze 25 cases of nonresectable advanced hepatic alveolar echinococcosis in the Fourth Hospital of PLA from 2006 to 2009. RESULTS: There were 18 male and 7 female patients with a mean age of 41 years. Twelve cases were treated with albendazole alone. Eleven patients were treated with albendazole combined with percutaneous puncture. Two cases were treated with albendazole combined with other intervention. A course of albendazole administration lasted 2 weeks with a dose of 15-20 mg/(kg x d) for 3 course in general. Eighteen patients were followed up for 1-4 years. In albendazole group, 2 cases were effective and 7 cases were symptom-improved. Five patients got improved and 2 cases showed effective in albendazole combined with percutaneous puncture group. Two cases of albendazole combined with intervention group showed no efficacy. CONCLUSIONS: Long-term use of albendazole is the main treatment for nonresectable advanced hepatic alveolar echinococcosis.

Integrated metabolomics and network pharmacology approach to reveal immunomodulatory mechanisms of Yupingfeng granules.

Systems biology is an approach that employs modern biological techniques and methods to combine the overall regulation of the body by Chinese herbal formulas with systems analysis at the molecular level. In this study, the underlying immunomodulatory mechanisms of yupingfeng granules (YPFG) were investigated based on the integration of metabolomics and network pharmacology methods. Selected routine peripheral blood indicators, body weight, and organ indices related to immunity were firstly measured in order to evaluate the effects of YPFG in cyclophosphamide-induced immunocompromised rats. Plasma metabolomics analyses were carried out by UPLC-Q-TOF-MS combined with a multivariate data analysis. Our study indicates that the potential regulatory mechanism was related to bile acid and glycerophospholipid metabolism, involving the regulation of 11 metabolites, including 8 bile acids, 1 phosphatidylserine, and 2 phosphatidylethanolamines. By means of network pharmacology, the compound-target network between potential active components of YPFG and immune dysregulation was constructed, which releated to estrogen receptor, PPAR, MAPK, PI3K-Akt, JNK signaling pathways, and ubiquitin-mediated protein degradation. The immunomodulatory effect of YPFG may be exerted through regulating lipid metabolism, then bile acid metabolism and inflammation were affected. Biological verification was also performed on cyclophosphamide-induced immunocompromised BALB/c mice. Flavonoid and saponin, two types of compounds in YPFG, were found to be the major active ingredients in the immunomodulatory effects of YPFG, and these components may regulate the abnormal metabolism of bile acids by enhancing the expression of FXR and LXRα. This work elucidated active ingredients, potential biomarkers, and mechanisms of action in the immunoregulatory effects of YPFG from the perspective of systems biology, which provides a scientific basis for its precise clinical medication.

Method for rapidly discovering active components in Yupingfeng granules by UPLC-ESI-Q-TOF-MS.

Yupingfeng granules (YPFG) were isolated from a traditional Chinese medicine (TCM) formulation composed of three herbs (Astragali Radix, Atractylodis Macrocephalae Rhizoma, and Saposhnikoviae Radix). This formulation is used in TCM to tonify qi, and it can help strengthen exterior and reduce sweating. Nevertheless, the active components of YPFG remain unclear. In this study, the chemical constituents of YPFG were systematically characterized by ultra-performance liquid chromatography coupled with electrospray ionization/ quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS). Fifty-eight compounds, namely, 20 flavonoids, 19 saponins, nine organic acids, four volatile coumarins, three lactones, one alkaloid, and two other components, were identified. In addition, the constituents of YPFG with the potential for in vivo bioactivities following oral administration were investigated in Sprague-Dawley rats. Thirteen compounds, namely, 11 flavonoid-related and 2 saponin-related components, were detected in rat plasma. After enriching flavonoids and saponins in YPFG by extraction, the extracts and YPFG were administrated to immunosuppressed rats, respectively. Plasma samples were analyzed by UPLC-ESI-Q-TOF-MS, and principal component analysis (PCA) confirmed that the extracts had similar effects to YPFG. This method could discover active ingredients in YPFG quickly and provide a scientific basis for quality control and mechanism research.

Overexpression of pyruvate kinase M2 associates with aggressive clinicopathological features and unfavorable prognosis in oral squamous cell carcinoma.

Abnormal glucose metabolism mediated by pyruvate kinase M2 (PKM2) fuels cancer overgrowth and propagation. However, its expression and oncogenic roles in in oral squamous cell carcinoma (OSCC) remains incompletely known. Here, we aimed to investigate the expression of PKM2, its prognostic values and oncogenic functions using 7,12-dimethyl-1,2-bezan-tracene (DMBA)-induced hamster buccal pouch SCC model, primary OSCC specimens as well as in vitro cellular assays. We found that in DMBA-induced OSCC model, negative PKM2 expression was commonly observed in normal epithelial, while more PKM2 abundance was detected in hyperplasia, dysplasia and SCC. Overexpression of PKM2 in a major fraction of OSCC significantly associated with tumor size (P = 0.027), cervical node metastasis (P = 0.004) and clinical stages (P = 0.000). Patients with increased PKM2 had remarkably reduced overall and disease-free survival. Multivariate survival analysis further revealed that PKM served as a critical independent prognostic factor for patients' overall survival. Furthermore, impaired cell proliferation and migration, and reduced apoptosis were detected upon PKM2 knockdown in HN4 and HN12 cells. Taken together, our findings reveal that PKM2 is critically involved in OSCC initiation and progression probably by promoting cell proliferation and migration as well as reducing apoptosis. Its overexpression correlates with aggressive clinicopathological features and poor patients' outcome.

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-ß1-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.

The polycomb group protein EZH2 is a novel therapeutic target in tongue cancer.

EZH2, a core member of the Polycomb Repressor Complex 2 (PRC2), mediates transcriptional silencing by catalyzing the trimethylation of histone 3 lysine 27 (H3K27), which plays key roles in cancer initiation and progression. Here, we investigated the expression pattern and biological roles of EZH2 in tongue tumorigenesis by loss-of-function assays using small interference RNA and EZH2 inhibitor DZNep. Also we determined the therapeutic efficiency of DZNep against tongue cancer in vivo. We found that aberrantly overexpressed EZH2 was associated with pathological grade, cervical nodes metastasis and Ki-67 expression in tongue cancers. Elevated EZH2 correlated with shorter overall survival and showed significant and independent prognostic importance in patients with tongue cancer. Both genetic and pharmacological depletion of EZH2 inhibited cell proliferation, migration, invasion and colony formation and decreased CD44+ subpopulation probably in part through modulating p16, p21 and E-caherin. Moreover, DZNep enhanced the anticancer effects of 5-Fluorouracil. Furthermore, intratumoral EZH2 inhibition induced by DZNep intraperitoneal administration significantly attenuated tumor growth in a tongue cancer xenograft model. Taken together, our results indicate that EZH2 serves as a key driver with multiple oncogenic functions during tongue tumorigenesis and a new biomarker for tongue cancer diagnosis and prognostic prediction. These findings open up possibilities for therapeutic intervention against EZH2 in tongue cancer.