LncRNA ZFAS1 promotes laryngeal cancer progression through RBFOX2-mediated MENA alternative splicing.

Laryngeal cancer (LC) is the most common aggressive malignancy of the head and neck. LncRNA ZNFX1 antisense RNA 1 (ZFAS1) displays oncogenic properties in head and neck squamous cell carcinoma, but its regulatory role in laryngeal cancer progression remains obscure. Here, we found that ZFAS1 expression in laryngeal cancer tissues and cells was higher than that in adjacent normal tissues and normal nasopharyngeal epithelial cells. Highly expressed ZFAS1 was associated with advanced lymph node metastasis stages and clinical stages. ZFAS1 overexpression promoted LC cell proliferation, invasion, and N-cadherin and Vimentin expression, and suppressed E-cadherin expression. While ZFAS1 knockdown played an opposite role. Mechanistically, ZFAS1 stabilized RNA binding fox-1 homolog 2 (RBFOX2) protein expression by binding to RBFOX2, and RBFOX2 overexpression reversed the effect of ZFAS1 silence on cell functions. Moreover, highly expressed RBFOX2 led to skipping of MENA exon 11a and generating a pro-invasive isoform (MENAINV ). MENAINV overexpression effectively abolished the inhibitory effect of RBFOX2 knockdown on cell malignant progression. Furthermore, Hep2 cells infected with lentivirus-mediated ZFAS1 shRNA or negative control shRNA were subcutaneously injected into mice to assess the role of ZFAS1 in tumor growth. And the data showed that silencing ZFAS1 in vivo hindered xenograft tumor growth. In conclusion, silencing ZFAS1 alleviated malignant progression of laryngeal cancer cells and mouse xenograft tumor growth by regulating RBFOX2-mediated alternative splicing of MENA.

MTA1 promotes viability and motility in nasopharyngeal carcinoma by modulating IQGAP1 expression.

Nasopharyngeal carcinoma (NPC) is frequently seen in Chinese, especially the population that resides in southeast China. Metastasis-associated protein 1 (MTA1) is a chromatin modifier and plays a role in tumor cell metastasis. IQGAP1 is a ubiquitously expressed protein that contributes to cytoskeleton remodeling. This study aimed to investigate the role of MTA1 and IQGAP1 in NPC malignant transformation. MTA1 and IQGAP1 expression in NPC (n = 43) and control tissues (n = 31) were detected using qRT-PCR, immunoblot, and immunohistochemistry. MTA1 was overexpressed in CNE-1 and CNE-2 cell line by pcDNA3.1/MTA1 transfection. Dominant-negative p53 was transfected to inhibit p53 activity. si-IQGAP1 or dominant-negative IQGAP1 (IQGAP1ΔGRD) was used to suppress IQGAP1 activity. Cell proliferation was measured by CKK-8 assay. Cell migration was evaluated by Transwell assay. The results showed that MTA1 and IQGAP1 were highly expressed in NPC tissues compared with the controls. Forced expression of MTA1 accelerated cell proliferation and migration and upregulated IQGAP1 expression in a p53-independent way. Knockdown of IQGAP1 or transfection of dominant-negative IQGAP1 impeded tumor cell proliferation and migration as well as PI3K/Akt signaling induced by MTA1. In conclusion, MTA1 participates in NPC malignant transformation via regulating IQGAP1 expression and PI3K/Akt signaling pathway.

MicroRNA-26a inhibits proliferation and tumorigenesis via targeting CKS2 in laryngeal squamous cell carcinoma.

Laryngeal squamous cell carcinoma (LSCC) is one of the most common head and neck cancers, with high mortality and incidence. MicroRNA-26a (miR-26a) is involved in the development and progression of several tumours. However, the roles of miR-26a and its target CKS2 in LSCC progression are not yet clear. The mRNA and protein expression was determined using RT-PCR and Western blotting assay, respectively. Cell proliferation was detected using a Cell Counting kit-8 assay (CCK-8). Transwell assay was used to evaluate cell migration and invasion. Dual-luciferase reporter assay was applied to determine the relationship between miR-26a and CKS2. In addition, a tumour xenograft model in nude mice was established to further determine the effects of miR-26a on tumourigenesis. In this study, we found that miR-26a level was down-regulated in LSCC tissues and cell lines, while CKS2 expression was increased. Cell proliferation, migration, invasion and the expression of MMP2 and MMP9 was suppressed by miR-26a overexpression, but enhanced by inhibition of miR-26a. Dual-luciferase reporter assay demonstrated that CKS2 is a direct target of miR-26a in AMC-HN-8 cells. Overexpression of miR-26a caused a significant reduction in CKS2 expression, and reinforced expression of CKS2 abolished the tumour-suppressive function of miR-26a. Moreover, miR-26a inhibited tumour growth in vivo. Taken together, miR-26a inhibited proliferation and tumourigenesis of LSCC via targeting CKS2 in vitro and in vivo.

Suppression of T-type Ca2+ channels inhibited human laryngeal squamous cell carcinoma cell proliferation running title: roles of T-type Ca2+ channels in LSCC cell proliferation.

BACKGROUND: Despite the tight correlation between T-type Ca2+ channels and a great variety of tumors, the roles of alpha1G subunit of T-type Ca2+ channels in laryngeal squamous cell carcinoma (LSCC) have not yet been investigated. METHODS: In the present study, we examined the expression of alpha1G subunit of T-type Ca2+ channel in human LSCC tissues and cell lines. One human laryngeal squamous cell carcinoma cell line, Hep-2, was also examined for T-type channels using voltage-clamp recordings. Cell proliferation assays were performed in the presence or absence of T-type channel blocker mibefradil and alpha1G subunit sepcific siRNA. The cell cycle was determined by flow cytometry. RESULTS: Our results indicated that the a1G subunit of T-type Ca2+ channel is highly expressed in human laryngeal squamous cell carcinoma tissues and cell lines. alpha1G siRNA significantly down-regulated the protein expression of the alpha1G subunit. Both alpha1G siRNA and mibefradil inhibited Hep-2 cell proliferation and arrested cell cycle progression. CONCLUSIONS: Together, these findings suggest a functional role of T-type channels in certain laryngeal carcinomas, and that inhibition of T-type channels reduces cell proliferation via cell cycle arrest, suggesting that the alpha1G subunit of T-type Ca2+ channel may be used as a therapeutic target for treating LSCC.

Tumor suppressor TSLC1 is implicated in cell proliferation, invasion and apoptosis in laryngeal squamous cell carcinoma by regulating Akt signaling pathway.

Overwhelming evidence has demonstrated that TSLC1 (tumor suppressor in lung cancer 1), a novel tumor suppressor, is crucially implicated in various biological processes including progression, proliferation and apoptosis during tumorigenesis. However, the exact functions and molecular details of TSLC1 in laryngeal cancer remain ill-defined. Here, the expression of TSLC1 in laryngeal squamous cell carcinoma (LSCC) tissues and cells was detected, and the biological roles of TSLC1 in LSCC cells were investigated. The results showed that expressions of TSLC1 mRNA and protein were significantly reduced in LSCC tissues with low expression in 18 of 85 (21.18 %) and 16 of 85 (18.82 %), respectively. Additionally, statistical analysis revealed a significant correlation of TSLC1 expression with TNM staging and lymph node metastases (P < 0.05), but not related to age, gender and tumor differentiation (P > 0.05). Elevation of TSLC1 level inhibited cell proliferation, reduced cell invasion in vitro and induced cell apoptosis in Hep-2 cells, most importantly, TSLC1 upregulation decreased the level of pAkt, but not changed the level of total Akt in Hep-2 cells. Stepwise investigations demonstrated that overexpression of TSLC1 in Hep-2 cells increased caspase-3 activity and expressions of bax and p21 proteins but decreased the levels of bcl-2, MMP-2 and MMP-9 proteins. These data suggest that TSLC1 may exert essential roles in the progression and development of LSCC, and thus TSLC1 may be a potential molecular target for LSCC treatment.

Elevated expression of Nrf2 mediates multidrug resistance in CD133+ head and neck squamous cell carcinoma stem cells.

Enhanced expression of the ATP-binding cassette (ABC) transporter protein ABC sub-family G member 2 (ABCG2) in cancer stem cells (CSCs) plays a major role in chemotherapeutic drug efflux, which results in therapy failure and tumor relapse. In addition to downregulating apoptosis in CSCs, it has been reported that the transcriptional upregulation of the redox sensing factor Nrf2 is involved in the upregulation of ABCG2 expression and consequent chemoresistance. The current study investigated the presence of cancer stem-like side population (SP) cells from head and neck squamous cell carcinoma (HNSCC) samples, and evaluated the Nrf2 expression profile and multidrug resistance properties of HNSCC stem cells. Fluorescence-activated cell sorting was used for SP cells detection, while reverse transcription-polymerase chain reaction was used for the analysis of Nrf2 expression. The present study identified ~2.1% SP cells present in HNSCC specimens, which were positive for cluster of differentiation (CD)133 expression and displayed significantly elevated messenger RNA expression of Nrf2, compared with non-SP cells. These data suggest that the ABC transporter ABCG2 is highly upregulated in SP cells, and this results in multidrug resistance. In addition, these CD133+ cells underwent rapid proliferation and exhibited high self-renewal and tumorigenic properties. Taken together, the present findings suggest that elevated expression of Nrf2 mediated drug resistance in HNSCC CSCs, which may be one of the causative factors for cancer treatment failure. Therefore, novel anti-cancer drugs that downregulate the Nrf2 signaling pathway could effectively improve the treatment and survival rate of patients with HNSCC.

MiR-340 impedes the progression of laryngeal squamous cell carcinoma by targeting EZH2.

Laryngeal squamous cell carcinoma (LSCC) is a common malignant tumor of the otolaryngeal region and accounts for 1-2% of all malignancies diagnosed worldwide. miR-340 down-regulation and EZH2 up-regulation have been frequently identified in multiple cancers, but the role of miR-340 and EZH2 in LSCC has not been explored. In this study, we investigated the regulative role of miR-340 in EZH2 expression and LSCC progression. The results showed that EZH2 was up-regulated and miR-340 was down-regulated in both Hep-2 cells and LSCC tissues. Molecularly, our results confirmed that miR-340 directly targeted EZH2 gene and inhibited EZH2 expression. MTT assay and BrdU assay showed that miR-340 transfection reduced the cell proliferation ability of Hep-2 cells. The transwell assay indicated that the invasion and migration ability of Hep-2 cells was dramatically inhibited by miR-340 transfection. In addition, miR-340 transfection induced cell apoptosis with concomitant enhancement of Bax, increase of Caspase-3 expression and activity, and reduction of Bcl-2 expression in Hep-2 cells. Both miR-340 transfection and EZH2 knockdown induced p27 expression and suppressed PI3K/Akt activation in Hep-2 cells. Strikingly, EZH2 knockdown reduced cell proliferation, and EZH2 overexpression significantly rescued the miR-340-mediated suppressive effect on cell proliferation. Moreover, miR-340 could obviously induce the inhibition of Hep-2 cell-derived tumor growth and EZH2/p27 expression ratio in vivo. Taken together, these data suggest that miR-340 impedes LSCC progression by targeting EZH2 with the possible mechanism to enhance the expression of anti-oncogene p27 and suppress PI3K/Akt activation, providing a novel target and a potential therapeutic pathway against LSCC.

MiR-132 plays an oncogenic role in laryngeal squamous cell carcinoma by targeting FOXO1 and activating the PI3K/AKT pathway.

Increasing evidence indicates that the dysregulation of microRNAs is involved in tumor progression and development. The purpose of the present study was to explore the expression of microRNA-132 (miR-132) and its function in laryngeal squamous cell carcinoma (LSCC). The results showed that miR-132 expression was markedly upregulated in LSCC tissues and cell lines. Functional analyses indicated that overexpression of miR-132 enhanced cell proliferation and tumor growth, which resulted in the downregulation of p27 and p21 and the upregulation of cyclin D1. In addition, luciferase activity indicated that miR-132 directly targets FOXO1, and inhibits FOXO1 protein expression in LSCC cells. Further studies revealed that the ectopic expression of FOXO1 effectively reversed the cell growth induced by miR-132. Moreover, miR-132 also activated the PI3K/AKT pathway, which further decreased FOXO1 expression. In conclusion, these findings demonstrated that miR-132 plays an important oncogenic role in LSCC by modulating the PI3K/AKT/FOXO1 pathway at multiple levels, resulting in strong prognostic implication. Therefore, miR-132 might be a potential therapeutic strategy in LSCC.

[The expression and clinical significance of MyD88 in laryngeal cancer].

OBJECTIVE: To investigate the myeloid differentiation factor 88 (MyD88) expression in laryngeal carcinoma and its clinical significance. METHOD: Fifty-one patients with laryngeal carcinoma were collected, and all patients were confirmed by pathological diagnosis results. The expression of MyD88 protein was detected by immunohistochemical method in laryngeal cancer and its adjacent tissues to investigate the correlation among MyD88 expression, clinicopathological characteristics and prognosis of patients. RESULT: The positive expression rate of MyD88 in laryngeal cancer tissues was 68.6%, significantly higher than that in normal tissues adjacent to carcinoma of which positive expression rate was 11.8%; MyD88 positive rate had nothing to do with laryngeal cancer patients age, sex, differentiation and tumour location (all P > 0.05), but correlated with clinical stage (P < 0.01) and lymph node metastasis (P < 0.05). In addition, the study also found that the expression of MyD88 quantity was inversely proportional with the five-year survival rate. The survival rate of patients with higher expression of MyD88 was significantly lower than that of patients with lower expression (P < 0.05). CONCLUSION: MyD88 may be an important participant in the pathogenesis of laryngeal carcinoma, MyD88 targeted therapy may improve the prognosis of patients with laryngeal cancer.

[The diagnosis applying effects of ocular vestibular evoked myogenic potentials in BBPV disease].

OBJECTIVE: To investigate the diagnosis applying effects of ocular vestibular evoked myogenic potentials(oVEMP) in peripheral BPPV disease. METHOD: During September 2012 to January 2015, we selected 80 healthy people in our hospital medical center as the control group, choose the same period of primary benign paroxysmal positional vertigo as the observation group of 80 patients. Two groups were carried out fully functional auditory evoked potential analysis, determination of oVEMP and cervical vestibular evoked myogenic potentials (cVEMP) anomaly amplitude threshold, P1 latencies, N1 incubation period. RESULT: The cVEMP abnormal rate in the observation group was 28.8%, the oVEMP abnormal rate was 38.8%, while cVEMP and oVEMP abnormal rates in the control group was 1.3% and 2.5% respectively that compared to significant differences between the two groups (P < 0.05). The oVEMP test amplitude in the observation group was (5.98 ± 2.15) µv, the N1 incubation period was (10.03 ± 0.76)ms, while the control group were (4.09 ± 2.11)µv and (11.67 ± 0.78) ms that compared difference were statistically significant (P < 0.05). The cVEMP test amplitude in the observation group was (154.8 ± 43.9)2 µv, while the control group was (180.49 ± 45.34)µv, compared the difference was statistically significant (P < 0.05). CONCLUSION: Paroxysmal positional vertigo patients ocular vestibular evoked myogenic potentials abnormal rate is relatively high, the utricle dysfunction for more severe than the balloon can be the subject of an objective function of the ear stone judgment, judgment in favor of the disease.

MicoRNA-451 is a novel tumor suppressor via targeting c-myc in head and neck squamous cell carcinomas.

OBJECTIVE: Head and neck squamous cell carcinoma (HNSCC) represents as a common malignancy with increasing incidence in the worldwide. The fact of its poor survival rate urgently requires developing efficient predictive biomarkers for clinical use. MicroRNAs (miRNAs) recently represent as a novel direction for early diagnosis and prognosis prediction in HNSCC therapy. In this study, we comprehensively investigated the function and putative target of miRNA-451 in vitro. METHODS: The expression of miRNA-451 was detected in HNSCC tissues and cell lines by real-time PCR. Forced expression or inhibition of miRNA-451 was done by transient transfection of mimics or inhibitor of miRNA-451 into indicated cells, respectively. Cell proliferation was evaluated by cell counting and crystal staining. Afterwards, we perform western blot to verify the expression of the miRNA-451 predicted target, c-myc, after miRNA-451 was overexpressed. RESULTS: We showed that miRNA-451 was downregulated in paired HNSCC tissues as well as in cell lines. And overexpression of miRNA-451 in cells with low endogenous expression of miRNA-451 accelerated proliferation. To the contrast, knockdown of miRNA-451 in cells with high levels of miRNA-451 significantly reduced cell growth rate. Furthermore, we used bioinformatics and cellular methods to predict and prove that c-myc was targeted by miRNA-451, since forced expression of miRNA-451 leaded to decreased c-myc protein expression in HNSCC cells. CONCLUSION: Our findings identify miRNA-451 as a potential biomarker and suggest a key role of miRNA-451-c-myc pathway in HNSCC cell transformation, which could represent a novel therapeutic strategy in HNSCC treatment.

Laryngeal cancer risk and common single nucleotide polymorphisms in nucleotide excision repair pathway genes ERCC1, ERCC2, ERCC3, ERCC4, ERCC5 and XPA.

Because the molecular mechanisms underlying the development of laryngeal cancer are not well understood, we conducted a case-control study to determine the association between eight common SNPs in NER pathway genes and risk of laryngeal cancer, and the association between genetic polymorphisms and environmental factors. A 1:1 matched case-control study of 176 cases and 176 controls was conducted. Laryngeal cancer cases were more likely to smoke and drink (all P values<0.05). Subjects with the ERCC1 rs11615 CC genotype and C allele had an increased risk of laryngeal cancer. Similarly, individuals with the ERCC5 rs17655 GG genotype and G allele had an increased risk of laryngeal cancer. Gene-gene interaction analysis showed that subjects carrying ERCC1 rs11615 C allele and XPG/ERCC5 rs17655 G allele had a greatly increased risk of breast cancer. Stratified analysis revealed that the interaction between polymorphisms of ERCC1 rs11615 and ERCC5 rs17655 and smoking on cancer risk was statistically significant, and ERCC1 rs11615 polymorphisms also had a significant interaction with drinking habit. In conclusion, our study suggests that ERCC1 rs11615 and ERCC5 rs17655 polymorphisms are associated with increased risk of laryngeal cancer, and that they confer more risk among smokers and drinkers.

Endonasal endoscopic treatment of recurrent dacryocystitis.

This report assessed clinical conditions leading to recurrent dacryocystitis and success rates of its treatment by endonasal endoscopic dacryocystorhinostomy. Forty-eight patients with recurrent dacryocystitis underwent endonasal endoscopic surgery and were followed up for at least 6 months. High bone windows, small bone window openings, small lacrimal sac stomas, scar tissues, and organic diseases of the nasal cavity led to fistula closure. Out of 48 patients, 45 (93.8%) patients were cured by endonasal endoscopic surgery. Endonasal endoscopic dacryocystorhinostomy is beneficial for recurrent dacryocystitis.