Determining the association between repeatedly elevated serum gamma-glutamyltransferase levels and risk of respiratory cancer: A nationwide population-based cohort study.

BACKGROUND: Although elevated serum gamma-glutamyltransferase (GGT) is a known indicator of increased risk of several cancers, the clinical value of repeated measurements of GGT has not been determined. Therefore, we aimed to investigate whether repeatedly elevated serum GGT levels are associated with the risk of respiratory cancer incidence. METHODS: We included participants who had undergone the Korean Health screening four times during 2009-2012 and had previously undergone four consecutive examinations. Those who were diagnosed with respiratory cancer before the date of examination were excluded. The participants obtained one GGT point if their GGT levels were in the highest quartile (the quartile 4 group). We analyzed the association between GGT points and respiratory cancer incidence by Cox proportional hazard models. RESULTS: During mean follow-up of 6.39 ± 1.2 years, 3,559,109 participants were enrolled. Of them, 8,944 (0.34%) men and 1,484 (0.14%) women were newly diagnosed with respiratory cancer. In multivariate analysis adjusted for confounding factors, male participants with 4 GGT points had a significantly higher hazards of developing respiratory cancer than those with 0 GGT points (hazard ratio [HR]: 1.39; 95% confidence interval [CI]: 1.31-1.48). Among female, participants with the highest points of GGT also had sixfold increased risk of developing laryngeal cancer. However, no significant association was observed between GGT points and lung cancer incidence among women (HR: 0.95; 95% CI: 0.81-1.11). CONCLUSION: Repeatedly elevated serum levels of GGT were associated with a higher risk of respiratory cancer incidence, especially in men. This finding suggests that physicians can identify a person with a higher risk of respiratory cancer through a simple repeated measurement of GGT.

HDAC1 regulates the chemosensitivity of laryngeal carcinoma cells via modulation of interleukin-8 expression.

Chemotherapies such as 5-fluorouracil (5-FU) and cisplatin (CDDP) have been widely used to treat laryngeal squamous cell carcinoma (LSCC), the second most common head and neck squamous cell carcinoma. However, chemoresistance seriously impairs chemotherapeutic efficacy. Our present study reveals that 5-FU and CDDP treatment increase the expression of histone deacetylase 1 (HDAC1) in LSCC cells. Consistently, increased levels of HDAC1 are observed in chemoresistant cells. Knockdown of HDAC1 significantly restores the sensitivity of LSCC cells, as HDAC1 increases the expression of interleukin-8 (IL-8), which is essential for LSCC chemoresistance. Mechanistically, HDAC1 directly initiates the transcription of IL-8 though binding to its promoter. Simultaneously, si-HDAC1 increases the levels of miR-93, which binds to the 3'UTR of IL-8 mRNA to trigger its degradation. In summary, the HDAC1/IL-8 axis can confer chemotherapeutic resistance to LSCC cells.

New insights into erythropoietin and erythropoietin receptor in laryngeal cancer tissue.

ABSTRACT: To investigate whether laryngeal cancer cells express erythropoietin (Epo) and erythropoietin receptor (EpoR) and what is their possible relationship with clinical and pathological features of the tumor.We performed immunohistochemical analysis of Epo and EpoR expression on 78 tissue samples of invasive and in situ squamous cell laryngeal carcinoma.The statistical analysis showed a weak positive and statistically significant correlation of EpoHS and EpoR HS expression levels. Epo HS and EpoR HS levels did not correlate with patient sex or age, type of diagnosis, cancer stage, histological tumor grade, presence or absence of disease recurrence, type of oncologic cancer therapy provided, or results of selected laboratory blood work. The results show a statistically significant difference in Epo expression with respect to survival.We confirmed the presence of Epo an EpoR in malignant laryngeal tumors and demonstrated the correlation between Epo expression and survival. Further studies are needed to more precisely define the role of Epo and EpoR in treatment of patients with laryngeal cancer.

H+/K+ATPase Expression in the Larynx of Laryngopharyngeal Reflux and Laryngeal Cancer Patients.

OBJECTIVES: The gastric H+/K+ ATPase proton pump has previously been shown to be expressed in the human larynx, however its contribution to laryngopharyngeal reflux (LPR) signs, symptoms and associated diseases such as laryngeal cancer is unknown. Proton pump expression in the larynx of patients with LPR and laryngeal cancer was investigated herein. A human hypopharyngeal cell line expressing the proton pump was generated to investigate its effects. STUDY DESIGN: In-vitro translational. METHODS: Laryngeal biopsies were obtained from three LPR and eight LSCC patients. ATP4A, ATP4B and HRPT1 were assayed via qPCR. Human hypopharyngeal FaDu cell lines stably expressing proton pump were created using lentiviral transduction and examined via transmission electron microscopy and qPCR for genes associated with inflammation or laryngeal cancer. RESULTS: Expression of ATP4A and ATP4B was detected in 3/3 LPR, 4/8 LSCC-tumor and 3/8 LSCC-adjacent specimens. Expression of ATP4A and ATP4B in FaDu elicited mitochondrial damage and expression of IL1B, PTGS2, and TNFA (P < .0001); expression of ATP4B alone did not. CONCLUSIONS: Gastric proton pump subunits are expressed in the larynx of LPR and LSCC patients. Mitochondrial damage and changes in gene expression observed in cells expressing the full proton pump, absent in those expressing a single subunit, suggest that acid secretion by functional proton pumps expressed in upper airway mucosa may elicit local cell and molecular changes associated with inflammation and cancer. LEVEL OF EVIDENCE: NA Laryngoscope, 131:130-135, 2021.

Presence of pepsin in laryngeal tissue and saliva in benign and malignant neoplasms.

OBJECTIVES: The current study was performed to determine the presence of pepsin in saliva and laryngeal tissue among participants with benign and malignant laryngeal neoplasms. STUDY DESIGN: Case-control study included three groups of patients with: (1) benign laryngeal neoplasms, (2) malignant laryngeal neoplasms and (3) control subjects without symptoms or signs of laryngopharyngeal reflux (LPR). METHODS: Eighty-one voluntary participants were included into study. They were recruited from a group of patients with histologically proven benign and malignant laryngeal neoplasms and in case of control subjects among patients with nasal septum deformation without symptoms of LPR. Morning saliva samples were collected preoperatively. Tumor biopsies were collected by directoscopy of larynx and the control samples from interarytenoid unit of larynx. All samples were analyzed by Enzyme-Linked Immunosorbent Assay (ELISA) and Immunohistochemistry. RESULTS: Pepsin was found in all samples of saliva and tissue biopsies in groups with malignant and benign neoplasms. The highest concentration of pepsin was found in a group of patients with malignant laryngeal neoplasms. Patients with benign laryngeal neoplasms had lower concentrations and the control subjects presented with the lowest concentration of pepsin measured from their saliva. Differences were not statistically significant. Immunohistochemical (IHC) analysis showed the largest number of high positive samples in the group of malignant lesions. CONCLUSION: These results suggest that pepsin and LPR can contribute to the development of benign and malignant laryngeal neoplasms. Further prospective studies, with far more patients, are necessary to prove the role of pepsin in multifactorial etiology of laryngeal neoplasms.

The clinical significance of methylation of MAGE-A1 and-A3 promoters and expression of DNA methyltransferase in patients with laryngeal squamous cell carcinoma.

PURPOSE: Abnormal DNA methylation plays an important role in clinical diagnosis and prognosis of various tumors. DNA methylation is catalyzed by DNA methyltransferase (DNMT). However, the methylation status of MAGE-A1 and MAGE-A3 promoter regions in LSCC is unclear. To investigate the methylation levels of MAGE-A1, -A3 in LSCC and corresponding normal tissues. The expression of DNMTs (DNMT1, DNMT3a and DNMT3b) in LSCC and the relationship between the methylation status of MAGE-A1, -A3 were analyzed. MATERIALS AND METHODS: We examined methylation status of MAGE-A1, -A3 in LSCC by using MSP. Meanwhile, the expression level of DNMTs in LSCC was detected by immunohistochemistry. And further analysis the correlation between DNMTs expression level and methylation status of MAGE-A1 and MAGE-A3. RESULTS: The unmethylation rate of MAGE-A1, -A3 were 39.62% and 46.23%. The expression of DNMTs was 33.02% to 37.74%. The level of demethylation of MAGE-A1 and MAGE-A3 were negative related to DNMTs protein. MAGE-A1 and MAGE-A3 unmethylation status and DNMT3a expression were independent prognostic factors for LSCC. CONCLUSIONS: The DNMTs may participate in the methylation process of MAGE-A1 and MAGE-A3, which may play an important role in the occurrence and development of LSCC.

Andrographolide sensitizes Hep-2 human laryngeal cancer cells to carboplatin-induced apoptosis by increasing reactive oxygen species levels.

Andrographolide is a natural diterpenoid from Andrographis paniculata that has been proposed as an anticancer agent as well as a chemosensitizer for use in combination with anticancer drugs. Carboplatin is the first-line chemotherapeutic agent for advanced laryngeal carcinoma. However, the clinical efficacy of carboplatin is limited by drug resistance and side effects. The aim of this study was to investigate whether andrographolide has a synergistic antitumor effect with carboplatin on human laryngeal cancer cells. Hep-2 cells were exposed to andrographolide with or without carboplatin. The effects of indicated therapies were examined using the Cell Counting Kit-8 assay, the colony-forming assay, the Hoechst 33342/PI double staining, and flow cytometry analysis. The molecular mechanism was assessed by reactive oxygen species (ROS) detection and western blot. At the sublethal concentration, andrographolide increased carboplatin sensitivity of Hep-2 cells by increasing carboplatin-induced apoptosis and inhibiting cell viability. Moreover, we found that andrographolide sensitized carboplatin mainly through the induction of ROS generation and apoptotic signaling. Taken together, these results indicate that andrographolide, along with carboplatin, synergistically inhibited cell proliferation and induced mitochondrial apoptosis of Hep-2 cells by increasing the intracellular ROS, regulating the mitogen-activated protein kinase and phosphatidylinositol 3-kinase (PI3K/AKT) pathways, altering the BCL2/BAX ratio, and ultimately activating the cleavage of Caspase-3 and PARP. These results suggest that andrographolide sensitizes human laryngeal cancer cells to carboplatin-induced apoptosis by increasing ROS levels.

Caspase complex in laryngeal squamous cell carcinoma.

Caspases (cysteine-aspartic proteases) represent a family of enzymes that modify several functions crucial for cell homeostasis such as inflammation and apoptosis. According to their implication in the apoptotic pathways, caspases are characterized as initiators and executioners, respectively. In the first group have been inserted caspase-2,-8,-9, and -10, whereas caspase-3,-6, and-7 belong to the second category. All of these normal actions of the caspase complex that induce apoptosis are altered in carcinoma progression and establishment. In cancer tissues, programmed cell death is inhibited due to a deregulation in expression of apo- and anti-apoptotic proteins. This genetic imbalance drives the cancer cell to immortalization which reflects the aberrant tissue proliferation. For this reason, caspases and the other apoptotic molecules are considered as important targets for specific targeted therapeutic strategies for enhancing the apoptotic levels inside the malignant tumor cells cores. In the current review we explored the role of caspases deregulation in laryngeal squamous cell carcinoma (LSCC). In malignancies -including LSCC- its deregulation leads the cells to immortalization due to apoptosis inhibition and telomerase overexpression. Caspase-dependent apoptotic rates are decreased in LSCC. For this reason, caspases are considered a very promising target for applying targeted therapeutic strategies in order to enhance apoptosis in the corresponding patients suffering of LSCC.

Anticancer Activity of Mukonal Against Human Laryngeal Cancer Cells Involves Apoptosis, Cell Cycle Arrest, and Inhibition of PI3K/AKT and MEK/ERK Signalling Pathways.

BACKGROUND Laryngeal cancer is one of the major malignancies of the neck and head and is responsible for considerable mortality across the globe. The treatments for laryngeal cancer mainly involve surgical interventions followed by chemotherapy. However, due to unsatisfactory results, constant relapses and the adverse effects associated with the currently used drugs, there is pressing need to develop effective drug options for treatment of laryngeal cancer. Therefore, this study was undertaken to investigate the anticancer effects of a plant-derived alkaloid, Mukonal, against human AMC-HN-8 laryngeal cancer cells. MATERIAL AND METHODS The WST-1 and clonogenic assays were employed to determine the cell viability. Apoptosis was detected by Hoechst and AO/EB staining. Cell migration and cell cycle analysis was performed by Transwell assay and flow cytometry, respectively. Protein expression was examined by Western blotting. RESULTS The results revealed that Mukonal reduced the viability of laryngeal cancer cells dose-dependently. The IC50 of Mukonal was found to be 10 µM. However, the effects of Mukonal on the normal HuLa-PC cells was found to be 140 µM. The decrease in the viability of the AMC-HN-8 laryngeal cancer cells was found to be due to the induction of apoptosis and G2/M cell cycle arrest. Mukonal also suppressed the cell migration and of the AMC-HN-8 laryngeal cancer cells. Mukonal could also inhibit the PI3K/AKT and MEK/ERK signalling pathways in a concentration-dependent manner. CONCLUSIONS Taken together, we conclude that Mukonal could prove a beneficial lead molecule for the treatment of laryngeal cancer.

Decreased expression of protein tyrosine kinase 6 contributes to tumor progression and metastasis in laryngeal squamous cell carcinoma.

BACKGROUND: PTK6 is involved in cell proliferation, invasion and migration. Patients with lower PTK6 expression predicts poor prognosis of LSCC. However, the mechanism of PTK6 in LSCC progression remains unclear. We investigated the role of PTK6 in the pathogenesis of LSCC. METHODS: Human LSCC tissues and paired adjacent non-tumor tissues were obtained to evaluate PTK6 expression. The biological function of PTK6 in LSCC was determined by overexpression of PTK6 in Hep-2 cells in vitro and in nude mice. The potential PTK6 target factors and signaling pathways were identified by Western blotting assay and immunohistochemical staining. RESULTS: PTK6 was downregulated in tissues of human LSCC. Biological function investigation of PTK6 demonstrated that overexpression of PTK6 significantly decreased cell growth, clonogenicity, invasion and migration capacity in vitro and suppressed xenograft tumor growth as well as lung metastasis in vivo. PTK6 suppresses LSCC proliferation mainly by inhibiting c-myc and cyclinD1 expression. In addition, PTK6 promotes cell apoptosis in LSCC. Moreover, PTK6 mitigated LSCC invasion and migration through regulating EMT and MMP-9. CONCLUSION: PTK6 plays a tumor suppressor role in LSCC by regulating c-myc and cyclinD1 expression, cell apoptosis, EMT and MMP-9.

NSD1- and NSD2-damaging mutations define a subset of laryngeal tumors with favorable prognosis.

Squamous cell carcinomas of the head and neck (SCCHN) affect anatomical sites including the oral cavity, nasal cavity, pharynx, and larynx. Laryngeal cancers are characterized by high recurrence and poor overall survival, and currently lack robust molecular prognostic biomarkers for treatment stratification. Using an algorithm for integrative clustering that simultaneously assesses gene expression, somatic mutation, copy number variation, and methylation, we for the first time identify laryngeal cancer subtypes with distinct prognostic outcomes, and differing from the non-prognostic laryngeal subclasses reported by The Cancer Genome Atlas (TCGA). Although most common laryngeal gene mutations are found in both subclasses, better prognosis is strongly associated with damaging mutations of the methyltransferases NSD1 and NSD2, with findings confirmed in an independent validation cohort consisting of 63 laryngeal cancer patients. Intriguingly, NSD1/2 mutations are not prognostic for nonlaryngeal SCCHN. These results provide an immediately useful clinical metric for patient stratification and prognostication.

Deregulation of PTEN Expression in Laryngeal Squamous Cell Carcinoma Based on Tissue Microarray Digital Analysis.

BACKGROUND/AIM: Phosphatase and tensin homolog (PTEN) (gene locus: 10q23.3) -a tumor suppressor gene- is deleted, mutated or epigenetically hyper-methylated in a variety of malignancies. PTEN acts as a negative regulator in PI3K/AKT/mTOR signaling transduction pathway. Our aim was to investigate PTEN protein expression patterns in laryngeal squamous cell carcinomas (LSCC). MATERIALS AND METHODS: Using tissue microarray technology, fifty (n=50) primary LSCCs were cored and re-embedded into one recipient block. Immunohistochemistry and digital image analysis were implemented for evaluating protein expression levels. RESULTS: Abnormal protein expression (low to negative staining intensity values) was observed in 28/50 (56%) tissue cores. Overall PTEN expression was associated with the anatomical region of the malignancies (p=0.039), whereas a borderline correlation with the differentiation grade was also assessed (p=0.05). CONCLUSION: Aberrant expression of PTEN tumor-suppressor gene in LSCCs seems to affect their biological behavior. Well-differentiated tumors express moderate to high protein levels, an evidence of normal gene function, whereas loss of its expression correlates with a progressive tumor dedifferentiation. Additionally, loss of its expression is detected more frequently in specific anatomical regions of the larynx (glottis, predominantly, and partially supraglottis).

Topoisomerase I deregulation in laryngeal squamous cell carcinomas based on tissue microarray analysis.

PURPOSE: Topoisomerases (types: I/IIa-b/IIIa-b) represent a super-family of nucleic enzymes involved in the DNA replication, transcription, recombination, and also chromosome topological formation. Topoisomerase's I (Topo I- gene location: 20q12) aberrant expression is a frequent genetic event in a variety of solid malignancies. Topo I inhibition promotes cell death due to DNA damage and for this reason it is a target for specific targeted chemotherapy (camptothecin, topotecan, irinotecan). Our aim was to investigate the role of abnormal Topo I protein expression in laryngeal squamous cell carcinomas (LSCC) in which there are very limited data regarding the influence of the marker. METHODS: Using tissue microarray (TMA) technology, 50 formalin-fixed, paraffin-embedded primary laryngeal SCCs were cored and re-pembedded into one recipient block. Immunohistochemistry was performed using anti- Topo I antibody. Digital image analysis was also implemented for evaluating objectively the protein expression levels on the corresponding stained nuclei. RESULTS: Topo I protein overexpression (moderate to high staining intensity values) was observed in 32/50 (64%) tissue cores, whereas low expression rates were detected in 18/50 (36%) cases. Topo I overall expression was strongly associated with the differentiation grade of the examined tumors (p=0.021). No other statistical correlations were identified. CONCLUSIONS: Topo I overexpression is observed in a significant subset of LSCCs affecting the level of differentiation in them. Additional molecular studies focused on the mechanism of Topo I gene/protein deregulation (i.e. amplification, abnormal epigenetic promoter methylation, mRNA aberrant expression) are necessary discriminating the eligible patients for applying specific chemotherapeutic strategies based on anti-Topo I agents.

Up-Regulation of Angiotensin-Converting Enzyme (ACE) Enhances Cell Proliferation and Predicts Poor Prognosis in Laryngeal Cancer.

BACKGROUND The angiotensin-converting enzyme (ACE, CD143) gene plays a crucial role in the pathology of many cancers. Previous studies mostly focused on the gene polymorphism, but the other functions of ACE have rarely been reported. The purpose of this study was to investigate the expression of ACE and its biological function, as well as its prognostic value, in laryngeal cancer. MATERIAL AND METHODS The expression of ACE was detected by quantitative real-time polymerase chain reaction (qRT-PCR) analysis in 106 patients with laryngeal cancer and 85 healthy people. Then the cell proliferation was estimated after the cell lines Hep-2 were transfected with pGL3-ACE and empty vector, respectively. In addition, the relationship between ACE expression and clinicopathologic characteristics was analyzed. Finally, Kaplan-Meier analysis was used to evaluate the overall survival of patients with different ACE expression, while Cox regression analysis was conducted to reveal the prognostic value of ACE in laryngeal cancer. RESULTS Our results demonstrate that ACE is over-expressed in laryngeal cancer and thus promotes cell proliferation. The up-regulation of ACE was significantly influenced by tumor stage and lymph node metastasis. Patients with high ACE expression had a shorter overall survival compared with those with low ACE expression according to Kaplan-Meier analysis. The ACE gene was also found to be an important factor in the prognosis of laryngeal cancer. CONCLUSIONS Our study shows that the ACE gene was up-regulated, which promoted the cell proliferation, and it could be an independent prognostic marker in laryngeal cancer.

Enhanced miR-9 promotes laryngocarcinoma cell survival via down-regulating PTEN.

MicroRNAs (miRNAs) play important roles in gene regulation during laryngocarcinoma. MiR-9 is a potential oncomiR, but its function in laryngocarcinoma is not known. The aim of this study is to investigate the roles of miR-9 in laryngocarcinoma. We found miR-9 expression was higher in laryngocarcinoma tissues compared with their normal controls, so did the laryngocarcinoma cells. Cellular function of miR-9 indicated that miR-9 restoration in laryngocarcinoma cells could promote cell proliferation and metastasis. Phosphatase and tensin homolog (PTEN) was predicted as a target gene of miR-9 and verified using luciferase reporter assay. PTEN expression was down-regulated in the laryngocarcinoma cells with miR-9 overexpression. We also found that miR-9 expression was negatively associated with PTEN expression in laryngocarcinoma tissues.

[Analysis of association of human 8-oxoguanine giycosylase 1 polymorphism with the susceptibility of laryngeal cancer].

Objective: To study the association between human 8-oxoguanine giycosylase 1 (hOGG1) gene polymorphisms and the risk of laryngeal carcinoma. Methods: A total of 86 patients with laryngeal carcinoma treated in The Air Force General Hospital and the Bozhou People's Hospital of Anhui Province from Jan 2010 to Dec 2014 were included in experimental group, and 86 healthy adults were selected as control group. The hOGG1 gene polymorphisms of subjects in two group were detected with by polymerase chain reaction amplification and gene sequencing technology, the differences in hOGG1 gene polymorphisms between two groups were analyzed. Results: The frequencies of hOGG1 gene heterozygous type (Ser/Cys) and mutant type (Cys/Cys) in experimental group were higher than those in control group(P<0.05). Compared to individuals with hOGG1 gene Ser/Ser, individuals with hOGG1 gene Ser/Cys had a 2.97-fold increased risk of laryngeal carcinoma, and individuals with hOGG1 gene Cys/Cys had a 8.09-fold increased risk of laryngeal carcinoma. Stratified by smoking or not, it was found that the proportion of heterozygous type or mutant type in smokers was higher significantly than non-smokers (P<0.05). Conclusion: Individuals with hOGG1 gene heterozygous type (Ser/Cys) or mutant type (Cys/Cys) have a higher risk of laryngeal carcinoma, with interaction between these gene types and smoking, and the gene types could be used as predictors for the occurrence of laryngeal carcinoma.

A combined modality of carboplatin and photodynamic therapy suppresses epithelial-mesenchymal transition and matrix metalloproteinase-2 (MMP-2)/MMP-9 expression in HEp-2 human laryngeal cancer cells via ROS-mediated inhibition of MEK/ERK signalling pathway.

Photodynamic therapy (PDT) has been developed as a promising treatment modality for laryngeal cancer. 9-Hydroxypheophorbide α (9-HPbD), a novel chlorophyll-derived photosensitizer, has a longer absorption wavelength, which increases the penetration of light to malignant tissues. Carboplatin (CBDCA), a second-generation platinum derivative, also has gained more popularity for the treatment of laryngeal cancer. Our previous studies have elucidated that 9-HPbD-PDT could inhibit the migration and invasion of HEp-2 cells. The objective of this study is to investigate the change of migration and invasion of HEp-2 cells induced by a combined modality of CBDCA and 9-HPbD-PDT in vitro. A wound healing assay, cell migration assay and Matrigel invasion assay were used to evaluate the cellular migration and invasion. Reactive oxygen species (ROS) and Western blots for epithelial-mesenchymal transition (EMT) markers (E-cadherin, N-cadherin and vimentin), MMPs (MMP-2 and MMP-9) and MEK/ERK signalling pathway were performed to investigate the possible mechanisms that may be involved. We observed that CBDCA and 9-HPbD-PDT administration synergistically inhibited the migration and invasion of HEp-2 cells. Moreover, the combined modality cooperatively repressed the EMT process and down-regulated expressions of MMP-2 and MMP-9 via ROS-mediated inhibition of phosphorylation in the MEK/ERK signalling pathway. Our results suggested that the combination of CBDCA and 9-HPbD-PDT might be a promising therapeutic strategy for laryngeal cancer metastasis.

Aurora kinase A revives dormant laryngeal squamous cell carcinoma cells via FAK/PI3K/Akt pathway activation.

Revival of dormant tumor cells may be an important tumor metastasis mechanism. We hypothesized that aurora kinase A (AURKA), a cell cycle control kinase, promotes the transition of laryngeal squamous cell carcinoma (LSCC) cells from G0 phase to active division. We therefore investigated whether AURKA could revive dormant tumor cells to promote metastasis. Western blotting revealed that AURKA expression was persistently low in dormant laryngeal cancer Hep2 (D-Hep2) cells and high in non-dormant (T-Hep2) cells. Decreasing AURKA expression in T-Hep2 cells induced dormancy and reduced FAK/PI3K/Akt pathway activity. Increasing AURKA expression in D-Hep2 cells increased FAK/PI3K/Akt pathway activity and enhanced cellular proliferation, migration, invasion and metastasis. In addition, FAK/PI3K/Akt pathway inhibition caused dormancy-like behavior and reduced cellular mobility, migration and invasion. We conclude that AURKA may revive dormant tumor cells via FAK/PI3K/Akt pathway activation, thereby promoting migration and invasion in laryngeal cancer. AURKA/FAK/PI3K/Akt inhibitors may thus represent potential targets for clinical LSCC treatment.

Are there possible associations between MnSOD and GPx1 gene variants for laryngeal cancer risk or disease progression?

Laryngeal squamous cell carcinoma (LSCC) is a multifaceted and genomically complex disease and cellular and preclinical studies have demystified wide ranging molecular mechanisms which underpin its development and progression and resistance against wide ranging molecular therapeutics. Oxidative stress is a widely studied molecular mechanism and reportedly involved in carcinogenesis. Increasingly it is being realized that accumulation of Reactive Oxygen Species (ROS) activates defensive mechanism to counteract oxidative stress induced damage. Manganese superoxide dismutase (MnSOD) and glutathione peroxidase (GPx) are important members of defensive machinery. We investigated whether the polymorphisms of MnSOD (Ala-9Val, rs4880) and GPx1 (Pro198Leu, rs1050450) are associated with LSCC and also evaluated possible interactions between these polymorphisms and various lifestyle factors or pathological features of patients. For this purpose, 67 LSCC patients and 73 healty controls were enrolled. Molecular assessment of MnSOD and GPx1 variants were determined with polymerase chain reaction-restriction fragment length polymorphism techniques. We found that the frequency of both heterozygous PL genotype and P allele was considerably higher in patients with advanced tumor stage (T3/T4) than in those with early tumor stage (T1/T2) (OR= 5.106; 95% CI=1.372-19.004; p<0.001, OR=5.787; 95% CI =1.564-21.414; p<0.001 respectively). Although the frequency of ValVal/LL combine genotype was significantly decreased (OR=0.204, 95% CI=0.055-0.760; p=0.021), the frequency of ValAla/PL combine genotypes was higher in patients with stage T3/T4 than in those patients with stage T1/T2 (p=0.027). Consequently, we have concluded that variants of GPx1 and MnSOD should not be considered as a risk factor of LSCC, only may be accepted as a prognostic markers. Use of new technologies such as metabolomics and deep DNA sequencing will prove to be helpful in developing a deeper knowledge related to how cancer cell metabolism adapts and provides a buffer against increased oxidative stress.

A Novel Sirtuin-3 Inhibitor, LC-0296, Inhibits Cell Survival and Proliferation, and Promotes Apoptosis of Head and Neck Cancer Cells.

BACKGROUND: The survival rate of patients with head and neck squamous cell carcinoma (HNSCC) stands at approximately 50% and this has not improved in decades. This study developed a novel sirtuin-3 (SIRT3) inhibitor (LC-0296) and examined its role in altering HNSCC tumorigenesis. MATERIALS AND METHODS: The effect of the SIRT3 inhibitor, LC-0296, on cell survival, proliferation, and apoptosis, and reactive oxygen species levels in HNSCC cells were studied. RESULTS: LC-0296 reduces cell proliferation and promotes apoptosis of HNSCC cells but not of normal human oral keratinocytes. This inhibitory effect is mediated, in part, via modulation of reactive oxygen species levels. Additionally, LC-0296 works synergistically to increase the sensitivity of HNSCC cells to radiation and cisplatin treatment. CONCLUSION: Development of novel SIRT3 inhibitors, such as LC-0296, might enable the development of new targeted therapies to treat and improve the survival rate of patients with head and neck cancer.