No abstract

ZFX (zinc finger protein, X-linked) gene locus on the human X chromosome is structurally similar to the zinc finger protein, Y-linked gene, which may constitute the primary sex-determining signal. However, the pathological roles of the dysfunction of ZFX gene in human disease such as cancer have not been addressed. Here, we analyzed the expression of ZFX in human laryngeal squamous cell carcinoma (LSCC) tissue specimens and found a significant up-regulation compared to corresponding non-tumorous LSCC tissue. Recombinant lentivirus expressing ZFX short hairpin RNA (shZFX) was constructed and infected Hep-2 human LSCC cells. We found that knockdown of ZFX gene resulted in suppression of proliferation and colony-forming ability of Hep-2 cells, and led to S phase cell cycle arrest. In addition, down-regulation of ZFX induced a significant enhancement of cell apoptosis and expression changes of apoptosis-related genes. These results suggest that high expression of ZFX is associated with LSCC progression and knockdown of ZFX may block tumor cell growth mainly by promoting cell apoptosis.

BackgroundLaryngeal squamous cell carcinoma (LSCC) is the most common type in head and neck squamous cell carcinoma (HNSCC), and the development and progression of LSCC are multistep processes accompanied by changes of molecular biology.ObjectiveThe purpose of this study was to investigate the molecular basis of tumorigenesis and regional lymph node metastasis in LSCC, and provide a set of genes that may be useful for the development of novel diagnostic markers and/or more effective therapeutic strategies.MethodsA total number of 10 patients who underwent surgery for primary laryngeal squamous cell carcinoma were recruited for microarray analysis. LSCC tissues compared with corresponding adjacent non-neoplastic tissues were analysed by Illumina mRNA microarrays, and LSCC tissues with regional lymph node metastasis and LSCC tissues without regional lymph node metastasis were analyzed in the same manner. The most frequently differently expressed genes screened by microarrays were also validated by qRT-PCR in another 42 patients diagnosed for LSCC.ResultsAnalysed by Illumina mRNA microarrays, there were 361 genes significantly related to tumorigenesis while 246 genes significantly related to regional lymph node metastasis in LSCC. We found that the six genes (CDK1, CDK2, CDK4, MCM2, MCM3, MCM4) were most frequently differently expressed functional genes related to tumorigenesis while eIF3a and RPN2 were most frequently differently expressed functional genes related to regional lymph node metastasis in LSCC. The expressions of these genes were also validated by qRT-PCR.ConclusionsThe research revealed a gene expression signature of tumorigenesis and regional lymph node metastasis in laryngeal squamous cell carcinoma. Of the total, the deregulation of several genes (CDK1, CDK2, CDK4, MCM2, MCM3, MCM4, EIF3a and RPN2) were potentially associated with disease development and progression. The result will contribute to the understanding of the molecular basis of LSCC and help to improve diagnosis and treatment.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. The five-year survival rate of HNSCC has not improved even with major technological advancements in surgery and chemotherapy. Currently, docetaxel, cisplatin, and 5-fluoruracil (TPF) treatment has been the most popular chemotherapy method for HNSCC; but only a small percentage of HNSCC patients exhibit a good response to TPF treatment. Unfortunately, at present, no reasonably effective prediction model exists to assist clinicians with patient treatment. For this reason, patients have no other alternative but to risk neoadjuvant chemotherapy in order to determine their response to TPF. In this study, we analyzed the gene expression profile in TPF-sensitive and non-sensitive patient samples. We identified a gene expression signature between these two groups. We further chose 10 genes and trained a support vector machine (SVM) model. This model has 88.3% sensitivity and 88.9% specificity to predict the response to TPF treatment in our patients. In addition, four more TPF responsive and four more TPF non-sensitive patient samples were used for further validation. This SVM model has been proven to achieve approximately 75.0% sensitivity and 100% specificity to predict TPF response in new patients. This suggests that our 10-genes SVM prediction model has the potential to assist clinicians to personalize treatment for HNSCC patients.

Solute carrier family 7, membrane 11 (SLC7A11) or (xCT) is a component of the cysteine-glutamate transporter, which plays a critical role in glutathione homeostasis which is important to protect cells from oxidative stress. SLC7A11 is distributed in various tissues and participates in the occurrence of a number of diseases, particularly in the pathogenesis of malignant tumors, but its role in laryngeal cancer development has not yet been clearly defined. The objective of the present study was to investigate the role of SLC7A11 in laryngeal squamous cell carcinoma (LSCC). We conducted immunohistochemistry and RT-PCR to evaluate the protein and mRNA levels of SLC7A11 in LSCC and in control tissues, respectively. The knockdown experiments were conducted with SLC7A11 short hairpin RNA (shRNA) lentivirus, and the protein and mRNA levels of SLC7A11 were assessed by RT-PCR and western blotting. The functional study of SLC7A11 in vitro was conducted by MTT assay, and the effects on the cell cycle were detected using flow cytometry. Immunohistochemical results revealed that the expression levels of SLC7A11, Ki-67 and p53 in LSCC tissues were higher than those in laryngeal dysplasia tissues. The Spearman rank correlation analysis revealed that the expression of SLC7A11 was positively correlated with the expression of p53 and Ki-67. Cox regression analysis and Kaplan-Meier plots confirmed that the expression levels of SLC7A11 were a prognostic factor for overall survival (OS) rates and postoperative recurrence of LSCC. Moreover, the functional study of SLC7A11 in vitro revealed that knockdown of SLC7A11 using shRNA inhibited cell proliferation by inducing cell cycle arrest at the G1 phase. Immunohistochemical and RT-PCR results and knockdown experiments of SLC7A11 revealed that SLC7A11 was involved in the progression of LSCC, and may provide clinical information for the evaluation of OS rates and postoperative recurrence of LSCC. Collectively, these observations suggest that SLC7A11 may be a vital biomarker for the diagnosis and prognosis in human LSCC, and targeting SLC7A11 appears to be a potentially significant method for LSCC treatment.

BackgroundEnhancer of zeste homolog 2 (EZH2) has been shown to contribute to tumour development and/or progression. However, the signalling pathway underlying the regulation of EZH2 in nasopharyngeal carcinoma (NPC) remains unclear. Since EZH2 contains the putative Glycogen synthase kinase 3 beta (GSK3β) phosphorylation motif ADHWDSKNVSCKNC (591) and may act as a possible substrate of GSK-3β, it is possible that inactivation of GSK3β may lead to excessive EZH2 expression in NPC.MethodWe first examined the expression of EZH2 and phosphorylated GSK3β (p-GSK3β) by immunohistochemical staining in NPC samples. Then, we evaluated the interaction of GSK3β and EZH2 using immunoprecipitation and immune blot. Moreover, we determined the effect of inhibition of GSK3β activity on EZH2 expression and tumor invasiveness in NPC cell lines in vitro. Finally, we evaluated the invasive properties of NPC cells after knocking down EZH2 expression with EZH2 siRNA.ResultsWe found that expression of EZH2 correlated with phosphorylated GSK3β (p-GSK3β) at Ser 9 (an inactivated form of GSK3β) in human nasopharyngeal carcinoma (NPC) samples. We also provided evidence that GSK3β is able to interact with EZH2 using immunoprecipitation and immune blot. Furthermore, we found that inhibition of GSK3β activity can lead to upregulation of EZH2 in NPC cell lines in vitro, with enhanced local invasiveness. By knocking down EZH2 expression with EZH2 siRNA, we found that these invasive properties were EZH2 dependent.ConclusionOur findings indicate that GSK3β inactivation may account for EZH2 overexpression and subsequent tumour progression, and this mechanism might be a potential target for NPC therapy.

BackgroundHypopharyngeal squamous cell carcinoma (HPSCC) is an aggressive head and neck squamous cell carcinoma with poor prognosis. Neoadjuvant chemotherapy (NACT) followed by concurrent chemoradiotherapy could provide better efficacy in HPSCC treatment. Identification of predictive biomarkers is critically needed to improve selection of patients who derive the most benefit from NACT. The aim of this study was to investigate whether transcobalamin I (TCN1) could be a novel predictive biomarker for NACT in HPSCC.MethodsWe collected biopsy specimens from 102 patients with primary locally advanced HPSCC. Messenger RNA (mRNA) and protein expression levels of TCN1 were analyzed using quantitative polymerase chain reaction and immunohistochemistry, respectively. The relationship between TCN1 expression, chemotherapy sensitivity, and clinical outcome was assessed using univariate Kaplan–Meier survival analyses and multivariate analysis with covariate adjustments. Furthermore, we knocked down TCN1 by small interfering RNA (siRNA) in HPSCC cell FaDu, tested the effects of TCN1 knockdown on cisplatin toxicity by MTT assay, and detected cisplatin-induced apoptosis by Western blotting.ResultsTCN1 expression was significantly lower in NACT-sensitive patients than nonsensitive patients at protein level (p=0.013) and mRNA level (p<0.001), indicating that low TCN1 expression predicts better NACT treatment response. Furthermore, TCN1 was an independent prognostic biomarker for both overall survival (p=0.047) and disease-free survival (p=0.05) in advanced HPSCC patients. In addition, in vitro experiments showed that genetic silencing of TCN1 using siRNA sensitized FaDu cells to cisplatin treatment with increased cell apoptosis.ConclusionLow expression of TCN1 might be a novel prognostic biomarker for predicting NACT sensitivity and clinical outcome in local advanced HPSCC patients.

Laryngeal squamous cell carcinoma (LSCC) is one of the most common types of head and neck malignant tumor; however, there is a lack of effective molecular targets for therapy. The present study detected the expression of three immunity‑associated molecules [forkhead box (FOX)3, interleukin (IL)‑10 and cluster of differentiation (CD)274] in 133 LSCC samples using immunohistochemistry (IHC); subsequently, the association between their expression and the clinical characteristics of LSCC were analyzed. Spearman's rank correlation method, Kaplan‑Meier and Cox regression model were used to analyze the correlations of the three proteins and their clinical significance. StarBase and miRTarBase databases were used to establish the competitive endogenous (ce)RNA network of the three molecules. IHC demonstrated that the positive expression rates of FOXP3, IL‑10 and CD274 were 68.4, 73.7 and 58.6% in 133 LSCC samples, respectively. In addition, it was identified that the expression of the three proteins was closely correlated with the clinical characteristics of LSCC, including lymph node metastasis and prognosis (P<0.05). There was also a significant association of co‑expression between any two proteins (P<0.001). Furthermore, the expression levels of FOXP3, IL‑10 and CD274 were negatively associated with the survival rate of patients with LSCC (P<0.05). The results of a Cox regression model suggested that the three proteins were prognostic risk factors for LSCC (P<0.05). The ceRNA network revealed that 10 microRNAs (miRs; including miR‑16‑5p and miR‑214‑3p), 123 long non‑coding RNAs (including X‑inactive specific transcript, H19 and metastasis associated lung adenocarcinoma transcript 1) and 408 circular RNAs (including ATP‑binding cassette subfamily C member 1 hsa_circ_001569 and ISY1 splicing factor homolog hsa_circ_001859) may regulate the expression of FOXP3, IL‑10 and CD274. The data generated from the present study may increase the understanding of the immune escape mechanisms of LSCC and may be beneficial for the development of a specific immunotherapy.