Upregulated TC1 and downregulated Chibby were correlated with the aberrant ß-catenin expression in laryngeal squamous cell carcinoma.

As an important member of Wnt/ß-catenin signaling pathway, the aberrant expression of ß-catenin has been implicated in many cancers. Chibby, a ß-catenin binding partner, is an antagonist involved in this pathway. In contrast, thyroid cancer 1 (TC1) as an activator of this pathway can relieve the antagonistic activity of Chibby on the ß-catenin-mediated transcription and is high expressed in human tumors. The objectives of this study were to examine the expression of TC1, Chibby, and ß-catenin and investigate the association among them in laryngeal squamous cell carcinoma (LSCC). The expression of TC1, Chibby, ß-catenin, c-Myc, Cyclin D1, and matrix metalloproteinase-7 (MMP-7) were examined by immunohistochemistry in samples from 53 LSCC patients. Compared with normal laryngeal squamous epithelium (NLSE), there were upregulated expression of TC1, downregulated expression of Chibby, and aberrant cytoplasmic expression of ß-catenin in the LSCC tissues (P < .001). The high expression of TC1 was correlated with the tumor site, advanced TNM and T stage, lymphovascular invasion, and poor differentiation in LSCC tissues (P < .050). There were correlations between the aberrant expression of ß-catenin and the tumor site, advanced TNM and T stage, lymphovascular invasion, perineurial invasion, and poor differentiation in LSCC tissues (P < .050). Upregulated TC1 and downregulated Chibby were correlated with aberrant expression of ß-catenin (P < .001), but no correlation between them (P = .076). The percent of abnormal expression of ß-catenin in LSCC was 96.00% in TC1+/Chibby-, 73.68% in TC1+/Chibby+, 0.00% in TC1-/Chibby-, and 0.00% in TC1-/Chibby + group (P < .001). High expression of c-Myc, Cyclin D1, and MMP-7 was observed in LSCC tissues (P < .001). There was statistically significant about the expression of Cyclin D1 and MMP-7 among the groups of TC1+/Chibby-, TC1+/Chibby+, TC1-/Chibby-, and TC1-/Chibby + (P < .001), but was not significance about the expression of c-Myc among them (P = .339). No association was found between overall survival and the expression of TC1, Chibby, and ß-catenin (P > .05). The upregulated expression of TC1 and downregulated expression of Chibby were correlated with the aberrant expression of ß-catenin and the high expression of Cyclin D1 and MMP-7 in LSCC tissues.

Intracellular galectin-3 is a lipopolysaccharide sensor that promotes glycolysis through mTORC1 activation.

How the carbohydrate binding protein galectin-3 might act as a diabetogenic and tumorogenic factor remains to be investigated. Here we report that intracellular galectin-3 interacts with Rag GTPases and Ragulator on lysosomes. We show that galectin-3 senses lipopolysaccharide (LPS) to facilitate the interaction of Rag GTPases and Ragulator, leading to the activation of mTORC1. We find that the lipopolysaccharide/galectin-3-Rag GTPases/Ragulator-mTORC1 axis regulates a cohort of genes including GLUT1, and HK2, and PKM2 that are critically involved in glucose uptake and glycolysis. Indeed, galectin-3 deficiency severely compromises LPS-promoted glycolysis. Importantly, the expression of HK2 is significantly reduced in diabetes patients. In multiple types of cancer including hepatocellular carcinoma (HCC), galectin-3 is highly expressed, and its level of expression is positively correlated with that of HK2 and PKM2 and negatively correlated with the prognosis of HCC patients. Our study unravels that galectin-3 is a sensor of LPS, an important modulator of the mTORC1 signaling, and a critical regulator of glucose metabolism.

KRT17 Accelerates Cell Proliferative and Invasive Potential of Laryngeal Squamous Cell Carcinoma (LSCC) through Regulating AKT/mTOR and Wnt/ß-Catenin Pathways.

Background: Laryngeal squamous cell carcinoma (LSCC) is a prevalent malignant tumor of the head and neck with a dismal prognosis. Keratin17 (KRT17) has been proven to serve as an oncogene in various cancers, but it has never been explored in LSCC. We proposed to assess the impact and possible mechanisms of KRT17 in the development of LSCC. Methods: Quantitative reverse transcription-PCR (qRT-PCR) was utilized to examine the mRNA levels. The Kaplan-Meier method was used to calculate the relationship between KRT17 expression and survival curves in LSCC patients. Cell counting kit-8 (CCK-8), colony formation, and flow cytometry assays were utilized to estimate LSCC cell proliferation. The migration and invasion abilities of LSCC cells were ascertained by wound-healing and transwell assays. Immunohistochemical and western blot assays were utilized to appraise protein levels. The xenograft tumor model was used to determine the effect of KRT17 on tumor growth. Results: In the present study, KRT17 was extremely high in LSCC tissues and cells and correlated with a poor prognosis. Inhibition of KRT17 weakens cell proliferative, migratory, and invasive abilities in LSCC and contributes to cell cycle arrest. Besides, we approved that knockdown of KRT17 extraordinarily restrained the xenograft tumor growth in vivo. We preliminarily investigated the role of KRT17 on the AKT/mTOR and Wnt/ß-catenin signaling axes and found that these signaling pathways were largely blocked by KRT17 deletion. Conclusion: Collectively, we uncovered that exhaustion of KRT17 suppresses LSCC progression through coordinating AKT/mTOR and Wnt/ß-catenin signaling axes, illustrating KRT17 as a promising biomarker for making strides in LSCC treatment.

Overexpression of Laminin 5γ2 Chain Correlates with Tumor Cell Proliferation, Invasion, and Poor Prognosis in Laryngeal Squamous Cell Carcinoma.

Objective: Laryngeal squamous cell carcinoma (LSCC) is a common malignant tumor. Laminin 5γ2 chain (LAMC2) was reported to be associated with tumorigenesis. This study explored the role of LAMC2 on LSCC progression by regulating the integrinß1/FAK/Src/AKT pathway. Methods: The level of LAMC2 in 46 LSCC patients was detected by qRT-PCR and western blot. Then the relationship between LAMC2 expression and LSCC malignancy as well as prognosis was analyzed, and the effect of LAMC2 expression on LSCC patient survival was also analyzed using the Kaplan-Meier survival curves. Afterwards, the LSCC cells were transfected with LAMC2 overexpression and knockdown vectors, the effect of LAMC2 on LSCC cell viability, proliferation ability, cell cycle, cell migration, and invasion were detected by CCK-8, colony formation, flow cytometry, wound healing, and Transwell assays. The expression of EMT-related biomarkers and integrin ß1/FAK/Src/AKT signaling-related proteins was detected by western blot. Moreover, the effect of LAMC2 on LSCC tumor growth was evaluated by in vivo xenograft experiments and western blot. Results: LAMC2 was expressed at high level in LSCC tissues and associated with poor prognosis. LAMC2 overexpression increased TU177 cell viability, proliferation ability, promoted cell cycle, cell migration, and invasion capacity. The expression of N-cadherin, vimentin, and integrinß1/FAK/Src/AKT related proteins was increased, while the expression of E-cadherin protein was decreased. When the LAMC2 knockdown in AMC-HN-8 cells had opposite effects. Furthermore, shLAMC2 decreased tumor volume and the expression of LAMC2, Ki-67 and integrinß1, but increased the expression of E-cadherin in LSCC tumor-bearing mice. Conclusion: The findings suggested that LAMC2 was overexpressed in LSCC and correlated with poor prognosis. LAMC2 knockdown inhibited LSCC progression by regulating the integrinß1/FAK/Src/AKT signaling pathway. Therefore, LAMC2 could be a target for LSCC therapy.

Recent Advances in Nanotheranostic Agents for Tumor Microenvironment-Responsive Magnetic Resonance Imaging.

Nanomaterials integrating a variety of excellent properties (such as controllable/suitable size, surface modifier, and multifunctionality) have attracted increasing attention in the biomedical field and have been considered a new generation of magnetic resonance imaging (MRI) contrast agents (CAs). In recent years, stimuli-responsive nanomaterials with specifically responsive ability have been synthesized as MRI CAs, which can significantly improve the diagnostic sensitivity and accuracy depending on their outstanding performance. Furthermore, the inherent tumor microenvironment (TME) of malignant tumor is considered to possess several unique features, such as low extracellular pH, redox condition, hypoxia, and high interstitial pressure, that are significantly different from healthy tissues. Hence, constructing nanomaterials for TME-responsive MRI as an emerging strategy is expected to overcome the current obstacles to precise diagnosis. This review focuses on recent advances of nanomaterials in their application of TME-responsive MRI that trigger the diagnostic function in response to various endogenous stimulations, including pH, redox, enzyme, and hypoxia. Moreover, the future challenges and trends in the development of nanomaterials serving as TME-responsive MRI CAs are discussed.

Effects of the Tight Junction Protein CLDN6 on Cell Migration and Invasion in High-Grade Meningioma.

BACKGROUND: Meningioma is a common tumor of the central nervous system, and malignant meningioma is highly aggressive and frequently recurs after surgical resection. Claudin 6 (CLDN6) is involved in cell proliferation, migration, and invasion and plays a role in maintaining tight junctions between cells and obstructing the movement of cells to neighboring tissues. METHODS: In the present study, we evaluated the effect of tight junction protein CLDN6 expression levels on meningioma invasiveness using silencing and overexpression constructs in both in vitro and in vivo models. The expression of CLDN6 at the mRNA and protein levels was measured using quantitative reverse transcription polymerase chain reaction and Western blot assays. RESULTS: We found that CLDN6 was expressed at higher levels in normal meningeal tissue and cell samples. Next, vectors with silenced and overexpressed CLDN6 were successfully established, and the expression of CLDN6 mRNA and protein in the IOMM-Lee and CH157-MN cell lines was downregulated after transfection with siRNA-CLDN6 and upregulated by transfection of the entire CLDN6 sequence vector. An in vitro assay revealed that abrogation of CLDN6 expression added to the capacity for tumor migration and invasion relative to the overexpression of CLDN6. In addition to the in vitro evidence, we observed a significant increase in tumor growth and invasion-associated gene expression, including matrix metalloproteinase-2, matrix metalloproteinase-9, vimentin, and N-cadherin, after silencing CLDN6 expression in vivo. CONCLUSIONS: CLDN6 might play an important role in meningioma migration and invasion and, thus, might serve as a novel diagnostic and/or prognostic biomarker and as a potential therapeutic target.

Identification of new hypoxia-regulated epithelial-mesenchymal transition marker genes labeled by H3K4 acetylation.

Hypoxia-induced epithelial-mesenchymal transition (EMT) involves the interplay between chromatin modifiers histone deacetylase 3 (HDAC3) and WDR5. The histone mark histone 3 lysine 4 acetylation (H3K4Ac) is observed in the promoter regions of various EMT marker genes (eg, CDH1 and VIM). To further define the genome-wide location of H3K4Ac, a chromatin immunoprecipitation followed by massively parallel DNA sequencing (ChIP-seq) analysis was performed using a head and neck squamous cell carcinoma (HNSCC) FaDu cell line under normoxia and hypoxia. H3K4Ac was found to be located mainly around the transcription start site. Coupled with analysis of gene expression by RNA sequencing and using a HDAC3 knockdown cell line, 10 new genes (BMI1, GLI1, SMO, FOXF1, SIRT2, etc) that were labeled by H3K4Ac and regulated by HDAC3 were identified. Overexpression or knockdown of GLI1/SMO increased or repressed the in vitro migration and invasion activity in OECM-1/FaDu cells, respectively. In HNSCC patients, coexpression of GLI1 and SMO in primary tumors correlated with metastasis. Our results identify new EMT marker genes that may play a significant role in hypoxia-induced EMT and metastasis and further provide diagnostic and prognostic implications.

Analysis of Epigenetic Regulation of Hypoxia-Induced Epithelial-Mesenchymal Transition in Cancer Cells by Quantitative Chromatin Immunoprecipitation of Histone Deacetylase 3 (HDAC3).

Epigenetics plays a key role in gene expression control. Histone modifications including acetylation/deacetylation or methylation/demethylation are major epigenetic mechanisms known to regulate epithelial-mesenchymal transition (EMT)-associated gene expression during hypoxia-induced cancer metastasis. Chromatin immunoprecipitation (ChIP) assay is a powerful tool for investigation of histone modification patterns of genes of interest. In this chapter, we describe a protocol that uses chromatin immunoprecipitation (ChIP) to analyze the epigenetic regulation of EMT marker genes by deacetylation of acetylated Histone 3 Lys 4 (H3K4Ac) under hypoxia in a head and neck cancer cell line FaDu cells. Not only a method of ChIP coupled by real-time quantitative PCR but also the detailed conditions are provided based on our previously published studies.

Telomerase Deficiency Causes Alveolar Stem Cell Senescence-associated Low-grade Inflammation in Lungs.

Mutations of human telomerase RNA component (TERC) and telomerase reverse transcriptase (TERT) are associated with a subset of lung aging diseases, but the mechanisms by which TERC and TERT participate in lung diseases remain unclear. In this report, we show that knock-out (KO) of the mouse gene Terc or Tert causes pulmonary alveolar stem cell replicative senescence, epithelial impairment, formation of alveolar sacs, and characteristic inflammatory phenotype. Deficiency in TERC or TERT causes a remarkable elevation in various proinflammatory cytokines, including IL-1, IL-6, CXCL15 (human IL-8 homolog), IL-10, TNF-α, and monocyte chemotactic protein 1 (chemokine ligand 2 (CCL2)); decrease in TGF-ß1 and TGFßRI receptor in the lungs; and spillover of IL-6 and CXCL15 into the bronchoalveolar lavage fluids. In addition to increased gene expressions of α-smooth muscle actin and collagen 1α1, suggesting myofibroblast differentiation, TERC deficiency also leads to marked cellular infiltrations of a mononuclear cell population positive for the leukocyte common antigen CD45, low-affinity Fc receptor CD16/CD32, and pattern recognition receptor CD11b in the lungs. Our data demonstrate for the first time that telomerase deficiency triggers alveolar stem cell replicative senescence-associated low-grade inflammation, thereby driving pulmonary premature aging, alveolar sac formation, and fibrotic lesion.

HSP60 overexpression increases the protein levels of the p110α subunit of phosphoinositide 3-kinase and c-Myc.

Heat shock protein 60 (HSP60) is a chaperone protein which plays an essential role in facilitating the folding of many newly synthesized proteins to reach their native forms. Increased HSP60 expression is observed in various types of human cancers. However, proteins induced by HSP60 to mediate transformation remain largely unknown. Here we show that HSP60 overexpression increases the protein levels of the p110α subunit of phosphoinositide 3-kinase (PI3K). The amino acid domain 288-383 of HSP60 is used to increase the protein levels. Overexpression of HSP60 also induces the levels of phosphorylated Akt. In addition, the amino acid domain 288-383 of HSP60 is used to induce c-Myc expression. Finally, a mono-ubiquitinated form of ß-catenin has a higher activity to activate ß-catenin downstream targets compared to wild-type ß-catenin. These results indicate that HSP60 overexpression induces the levels or activity of multiple oncogenic proteins to mediate transformation.

Epigenetic regulation of epithelial-mesenchymal transition by hypoxia in cancer: targets and therapy.

Intratumoral hypoxia followed by stabilization/activation of hypoxia-inducible factor 1 (HIF-1) and its downstream transcriptional factors, is one of the most important mechanisms inducing epithelial-mesenchymal transition (EMT), which has been widely accepted as a crucial step to generate early stage of tumor metastasis. Accumulating evidence suggests that epigenetic mechanisms play important roles in hypoxia-induced EMT and metastasis. These epigenetic regulations are mediated by various players including chromatin modifiers, transcriptional co-regulators, microRNAs, etc. In this review, we discuss how his tone-modifying enzymes and transcriptional co-regulators regulate EMT under hypoxic conditions. Developed or potential anticancer agents targeting epigenetic molecules regulating hypoxia-induced EMT are also discussed.

Positive therapy of andrographolide in vocal fold leukoplakia.

PURPOSE: Vocal fold leukoplakia is a premalignant precursor of squamous cell carcinoma. Although many efforts have been contributed to therapy of this disease, none exhibits a satisfactory result. The aims of this study were to investigate the effectiveness and feasibility of andrographolide therapy in vocal fold leukoplakia and to explore the preliminary mechanism underlying. MATERIALS AND METHODS: Forty-one eligible patients were enrolled in the study. The patients were treated for 10-minute exposures of 5 ml (25mg/ml) andrographolide injection aerosols twice a day, and 2 weeks was considered as one treatment course. Electronic laryngoscope was used to observe the condition of vocal fold leukoplakia during the treatment. Every patient received one or two treatment courses, and the follow-up was carried out for 12 months. Toxic reactions of treatments were evaluated on the basis of the standards of the United States MD Anderson Cancer Center. Moreover, laryngeal carcinoma cell line Hep2 was applied to explore the mechanism of effect of andrographolide. Anti-proliferative effect on Hep2, cell nuclear morphology, express of mitogen-activated protein kinases (MAPK) and pro-apoptotic protein were detected after andrographolide treatment. RESULTS: We found that andrographolide exhibited significant curative effects on treatments, which were accompanied by thinning of the lesion of leukoplakia, reduction in the whitish surface area, and return of pink or red epithelium. A complete response up to 85% was observed, and no toxic side effect events occurred during the study. No patient with a complete response had a recurrence in the follow-up. Moreover, cellular experiments in Hep2 indicated that andrographolide activated MAPK pathway and caspase cascade, and finally induced apoptosis in laryngeal carcinoma cell. CONCLUSIONS: The advantages of andrographolide are connected with minimally invasive and localized character of the treatment and no damage of collagenous tissue structures, which are more convenient and less painful for patients. These results suggest that andrographolide treatment is a viable strategy for curing vocal fold leukoplakia.

Interaction between NBS1 and the mTOR/Rictor/SIN1 complex through specific domains.

Nijmegen breakage syndrome (NBS) is a chromosomal-instability syndrome. The NBS gene product, NBS1 (p95 or nibrin), is a part of the Mre11-Rad50-NBS1 complex. SIN1 is a component of the mTOR/Rictor/SIN1 complex mediating the activation of Akt. Here we show that NBS1 interacted with mTOR, Rictor, and SIN1. The specific domains of mTOR, Rictor, or SIN1 interacted with the internal domain (a.a. 221-402) of NBS1. Sucrose density gradient showed that NBS1 was located in the same fractions as the mTOR/Rictor/SIN1 complex. Knockdown of NBS1 decreased the levels of phosphorylated Akt and its downstream targets. Ionizing radiation (IR) increased the NBS1 levels and activated Akt activity. These results demonstrate that NBS1 interacts with the mTOR/Rictor/SIN1 complex through the a.a. 221-402 domain and contributes to the activation of Akt activity.

Molecular regulation of telomerase activity in aging.

The process of aging is mitigated by the maintenance and repair of chromosome ends (telomeres), resulting in extended lifespan. This review examines the molecular mechanisms underlying the actions and regulation of the enzyme telomerase reverse transcriptase (TERT), which functions as the primary mechanism of telomere maintenance and regulates cellular life expectancy. Underpinning increased cell proliferation, telomerase is also a key factor in facilitating cancer cell immortalization. The review focuses on aspects of hormonal regulations of telomerase, and the intracellular pathways that converge to regulate telomerase activity with an emphasis on molecular interactions at protein and gene levels. In addition, the basic structure and function of two key telomerase enzyme components-the catalytic subunit TERT and the template RNA (TERC) are discussed briefly.

Nanoparticles for tumor targeted therapies and their pharmacokinetics.

Various types of nanoparticles, such as liposomes, polymeric micelles, dendrimers, superparamagnetic iron oxide crystals, and colloidal gold, have been employed in targeted therapies for cancer. Both passive and active targeting strategies can be utilized for nano-drug delivery. Passive targeting is based on the enhanced permeability and retention (EPR) effect of the vasculature surrounding tumors. Active targeting relies on ligand-directed binding of nanoparticles to receptors expressed by tumor cells. Release of loaded drugs from nanoparticles may be controlled in response to changes in environmental condition such as temperature and pH. Biodistribution profiles and anticancer efficacy of nano-drugs in vivo would be different depending upon their size, surface charge, PEGylation and other biophysical properties. This review focuses on the recent development of nanoparticles for tumor targeted therapies, including physicochemical properties, tumor targeting, control of drug release, pharmacokinetics, anticancer efficacy and safety. Future perspectives are discussed as well.