lithium-chloride and Carcinoma--Squamous-Cell

Forkhead box (FOX) proteins are a large family of transcription factors that are involved in multiple biological processes. FOXJ1, a member of the FOX family, has been found to participate in tumorigenesis. However, the role of FOXJ1 in laryngeal squamous cell carcinoma (LSCC) is still unclear. The aim of the present study was to explore the potential roles of FOXJ1 in LSCC. Our results showed that FOXJ1 was overexpressed in LSCC tissues and cell lines. Then the small interfering RNA targeting FOXJ1 (FOXJ1-siRNA) or control siRNA was transfected into TU-177 and AMC-HN-8 cells to knockdown FOXJ1. Cell Counting Kit-8 assay showed that knockdown of FOXJ1 inhibited the proliferation of LSCC cells. Transwell assay revealed that FOXJ1-siRNA-transfected cells showed significant reduction in cell migration and invasion compared to the cells transfected with control siRNA. FOXJ1 knockdown suppressed glycolysis in LSCC cells, which was illustrated by the reduced glucose consumption and lactate production. In addition, FOXJ1 knockdown inhibited the activation of the Wnt/β-catenin pathway, and the LiCl treatment mitigated the inhibitory effects of FOXJ1-siRNA on cell proliferation, migration, invasion, and glycolysis. These findings indicated that FOXJ1-siRNA executed its functions via suppressing the activation of the Wnt/β-catenin pathway.

Topics: Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Survival; Female; Forkhead Transcription Factors; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Glycolysis; Humans; Laryngeal Neoplasms; Lithium Chloride; Male; Middle Aged; Neoplasm Invasiveness; Up-Regulation; Wnt Signaling Pathway

Topics: Animals; Apoptosis; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Cell Self Renewal; Gene Expression Regulation, Neoplastic; Glycogen Synthase Kinase 3 beta; Humans; Hyaluronan Receptors; Lithium Chloride; Mice; Mouth Neoplasms; Neoplastic Stem Cells; Plant Lectins; Reactive Oxygen Species; Wnt Signaling Pathway; Xenograft Model Antitumor Assays

Although GSK3β has been reported to have contrasting effects on the progression of different tumors, it's possible functions in esophageal squamous cell carcinoma (ESCC) and the related molecular mechanisms remain unknown. Here, we investigated the expression, function, and molecular mechanism of GSK3β in the development of ESCC in vitro and in vivo. Though the expression of total GSK3β was significantly increased, the phosphorylated (inactivated) form of GSK3β (Ser9) was concurrently decreased in the cancerous tissues of patients with ESCC compared with controls, suggesting that GSK3β activity was enhanced in cancerous tissues. Further pathological data analysis revealed that higher GSK3β expression was associated with poorer differentiation, higher metastasis rates, and worse prognosis of ESCC. These results were confirmed in different ESCC cell lines using a pharmacological inhibitor and specific siRNA to block GSK3β. Using a cancer phospho-antibody array, we found that STAT3 is a target of GSK3β. GSK3 inhibition reduced STAT3 phosphorylation, and overexpression of constitutively active GSK3β had the opposite effect. Moreover, STAT3 inhibition mimicked the effects of GSK3β inhibition on ESCC cell migration and viability, while overexpression of a plasmid encoding mutant STAT3 (Y705F) abrogated these effects, and these results were further substantiated by clinicopathological data. In addition, a GSK3 inhibitor (LiCl) and/or STAT3 inhibitor (WP-1066) efficiently suppressed the growth of ESCC cells in a xenograft tumor model. Altogether, these results reveal that higher GSK3β expression promotes ESCC progression through STAT3 in vitro and in vivo, and GSK3β-STAT3 signaling could be a potential therapeutic target for ESCC treatment.

Topics: Animals; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Survival; Disease Progression; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Female; Gene Expression Regulation, Neoplastic; Glycogen Synthase Kinase 3 beta; Humans; Lithium Chloride; Male; Mice; Phosphorylation; Prognosis; Pyridines; Signal Transduction; STAT3 Transcription Factor; Survival Analysis; Tyrphostins; Up-Regulation

Oral squamous cell carcinoma is a common and lethal malignancy affecting the head and neck region. CCAT2 (colon cancer-associated transcript 2) gene is affiliated with long non-coding RNAs, which are often found to have important regulatory roles in cancers. This study aims to assess the expression and clinical significance of CCAT2 gene, identify its malignant biological behaviors, and explore the possible mechanisms in oral squamous cell carcinoma. CCAT2 expression was detected by quantitative real-time polymerase chain reaction, and its relationship with clinical factors was assayed using the Kaplan-Meier survival curve. The biological behaviors of CCAT2 and its potential mechanisms in oral squamous cell carcinoma were explored by the combined use of CCAT2 knockdown technology and the Wnt/β-catenin pathway agonist lithium chloride (LiCl). Our results showed that CCAT2 functioning as a potential oncogene was upregulated in oral squamous cell carcinoma. CCAT2 with high expression level was correlated with poor differentiation, higher T stage, and clinical stage, which made CCAT2 to be a prognostic biomarker in oral squamous cell carcinoma. LiCl-activated Wnt/β-catenin signaling pathway could partly restore the CCAT2-mediated malignant biological behaviors of oral squamous cell carcinoma cells by suppressing β-catenin, CCND1, and MYC and activating glycogen synthase kinase 3 beta expression. These findings might assist in the discovery of novel potential diagnostic and therapeutic target for oral squamous cell carcinoma, thereby improve the effects of clinical treatment in patients.

Topics: Adult; Aged; beta Catenin; Biomarkers, Tumor; Carcinoma, Squamous Cell; Cell Proliferation; Cyclin D1; Female; Gene Silencing; Humans; Kaplan-Meier Estimate; Lithium Chloride; Male; Middle Aged; Mouth Neoplasms; Prognosis; RNA, Long Noncoding; Wnt Signaling Pathway

During tumorigenesis, tumor suppressor and tumor-related genes are commonly silenced by aberrant DNA methylation in their promoter regions, which is one of the important determinants of susceptibility to 5-fluorouracil (5-FU) in oral squamous cell carcinoma (OSCC) cells. Here, we examine the chemotherapeutic efficacy of epigenetic agents on 5-FU cytotoxicity.. We investigated the effect of a DNA methyltransferase (DNMT) inhibitor, zebularine (Zeb), on the chemosensitivity of 5-FU and cisplatin (CDDP) by MTT and TUNEL methods, and compared the molecular mechanism of action with those of a GSK3beta inhibitor, LiCl, and an Hsp90 inhibitor, 17-AAG.. A significant apoptotic effect by a combination of Zeb or 17-AAG was found in CDDP treatment; however, considerable suppression of 5-FU-induced apoptosis was observed after incubation with Zeb, 17-AAG, or LiCl. Zeb's suppressive effects were associated with activation of the cAMP/PKA/CREB pathway, differing from mechanisms of 17-AAG and LiCl. Suppression of 5-FU-induced apoptosis by Zeb was not associated with increased Bcl-2 and Bcl-xL expressions dependent on transcription factor CREB, and with the expression level of thymidylate synthase.. In the present study, we identified a more detailed mechanism of action by which Zeb suppresses 5-FU-induced apoptosis. These results indicate that combination therapies have to be carefully investigated due to potential harmful effects in the clinical application of DNMT inhibitors.

Topics: Adjuvants, Immunologic; Antimetabolites, Antineoplastic; Antineoplastic Agents; Apoptosis; Benzoquinones; Blotting, Western; Carcinoma, Squamous Cell; Cell Line, Tumor; Cisplatin; Cyclic AMP Response Element-Binding Protein; Cyclic AMP-Dependent Protein Kinases; Cytidine; DNA (Cytosine-5-)-Methyltransferases; Fluorouracil; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; HSP90 Heat-Shock Proteins; Humans; In Situ Nick-End Labeling; Lactams, Macrocyclic; Lithium Chloride; Mouth Neoplasms; NF-kappa B; Phosphorylation; Proto-Oncogene Proteins c-bcl-2; Signal Transduction