Gain of function mutation in K(ATP) channels and resulting upregulation of coupling conductance are partners in crime in the impairment of Ca2+ oscillations in pancreatic ß-cells.

Gain of function mutations in the pore forming Kir6 subunits of the ATP sensitive K+ channels (K(ATP) channels) of pancreatic ß-cells are the major cause of neonatal diabetes in humans. In this study, we show that in insulin secreting mouse ß-cell lines, gain of function mutations in Kir6.1 result in a significant connexin36 (Cx36) overexpression, which form gap junctional connections and mediate electrical coupling between ß-cells within pancreatic islets. Using computational modeling, we show that upregulation in Cx36 might play a functional role in the impairment of glucose stimulated Ca2+ oscillations in a cluster of ß-cells with Kir6.1 gain of function mutations in their K(ATP) channels (GoF-K(ATP) channels). Our results show that without an increase in Cx36 expression, a gain of function mutation in Kir6.1 might not be sufficient to diminish glucose stimulated Ca2+ oscillations in a ß-cell cluster. We also show that a reduced Cx36 expression, which leads to loss of coordination in a wild-type ß-cell cluster, restores coordinated Ca2+ oscillations in a ß-cell cluster with GoF-K(ATP) channels. Our results indicate that in a heterogenous ß-cell cluster with GoF-K(ATP) channels, there is an inverted u-shaped nonmonotonic relation between the cluster activity and Cx36 expression. These results show that in a neonatal diabetic ß-cell model, gain of function mutations in the Kir6.1 cause Cx36 overexpression, which aggravates the impairment of glucose stimulated Ca2+ oscillations.

CXCL14 and miR-4484 serves as potential salivary biomarkers for early detection of peri-implantitis.

Peri-implantitis develops in 43.3% of implant patients, which affects tissues around the implant that may ultimately cause implant loss if not treated properly. Due to difficulties in detecting peri-implantitis in its early phases, implant failures are constantly on the rise. Therefore, new specific molecular markers need to be identified to prevent or limit disease progression in peri-implantitis patients. We investigated levels of CXCL9, CXCL12, and CXCL14 in saliva samples of 45 patients with commercially pure grade 4/5 Titanium-Aluminum-Vanadium implants. We analyzed the correlation of the chemokine levels using Pearson's Correlation test and investigated their power to discriminate peri-implantitis vs. non-peri-implantitis patients using receiver operating characteristic analysis. Our in silico investigation revealed CXCL9, CXCL12, and CXCL14 as predicted targets of miR-4484, which has been demonstrated as a powerful biomarker candidate for early detection of peri-implantitis in our previous study. We measured high CXCL9 and low CXCL14 levels in the saliva of peri-implantitis patients. We also reported that the CXCL14 level showed a significant positive correlation with miR-4484. Besides, CXCL14 together with miR-4484 in saliva differentiated peri-implantitis patients from non-peri-implantitis individuals with 100% success. We offer differential expressions of CXCL14 and miR-4484 in the saliva of patients with peri-implantitis as potential salivary biomarkers for early detection of this disease.

Oncogenic miR-1825 promotes head and neck carcinogenesis via targeting FREM1.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignant cancer type worldwide. Although the therapeutic modalities currently used for patients with HNSCC improved in recent decades, HNSCC prognosis is still poor. Therefore, it is an urgent necessity to understand the pathogenesis of HNSCC, to develop novel and effective treatment strategies, and to characterize and identify the oncogenes that are responsible for an aggressive HNSCC phenotype. In this study, we aimed to better understand the roles of miR-1825 in the pathogenesis of HNSCC. We examined the impacts of miR-1825 deregulation on the cancer-associated phenotypes using in vitro tests evaluating cell viability, clonogenicity, cell migration, invasion, apoptosis, and stem cell characteristics. In addition, we investigated the effects of miR-1825 overexpression on the tumor formation capacity of head and neck cancer cells in vivo using nude mice. We searched for potential targets of miR-1825 using microarray analysis and luciferase assay. We found that miR-1825 expression is upregulated in head and neck cells and clinical tumor samples in comparison to corresponding controls, where it potentially acts as an oncogene. We, then, showed that ectopic miR-1825 overexpression promotes cellular phenotypes related to head and neck cancer progression in vitro and has a stimulating potential on cancer formation in vivo. We also identified FREM1 as a direct target of miR-1825 and demonstrated its reduced expression in HNSCC samples using immunohistochemistry analysis. Collectively, we suggest that the miR-1825/FREM1 axis serves as an important mediator of HNSCC development, where miR-1825 acts as an oncogene.

Hypoxia-induced tumor exosomes promote angiogenesis through miR-1825/TSC2/mTOR axis in oral squamous cell carcinoma.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is characterized by enhanced angiogenesis resulting in poor prognosis despite improvements in diagnostic/therapeutic techniques. Here, we aimed at investigating potential roles of miR-1825 enclosed in OSCC-derived exosomes on angiogenesis under hypoxic conditions. METHODS: Effects of miR-1825 mimic/inhibitor as well as hypoxia-induced tumor derived exosomes on human umbilical vein endothelial cells (HUVECs) were evaluated using cell viability, migration/invasion, tube formation, and spheroid-based 3D angiogenesis assays. RESULTS: Hypoxic conditions caused significant increase in miR-1825 levels in OSCC cells and hiTDEs. miR-1825 alone and within hiTDEs promoted endothelial cell viability, migration, invasion, and angiogenic potential, which is reversed via inhibition of miR-1825 expression. miR-1825 within hiTDEs altered the angiogenesis potential of HUVEC cells via deregulation of TSC2/mTOR axis. CONCLUSIONS: We showed that hypoxia led to OSCC-derived exosome mediated transfer of miR-1825 to HUVECs and enhanced angiogenesis in OSCC in vitro.

Low vitamin D and high cholesterol facilitate oral carcinogenesis in 4NQO-induced rat models via regulating glycolysis.

OBJECTIVES: Diets and nutritional habits are critical during carcinogenic processes, where a diet poor in fruits and vegetables and rich in meat and other foods of animal origin facilitates carcinogenesis. In this study, we aimed at investigating the possible involvement of vitamin D deficiency (VDD) and high cholesterol (HC) together in oral squamous cell carcinoma (OSCC) through modulating glycolysis. SUBJECTS AND METHODS: We compared total cholesterol, LDL, HDL, triglycerides, LDH, and vitamin D levels of OSCC patients and control individuals. We used GEO datasets for gene set enrichment and 4-nitroquinoline-1-oxide induced in vivo oral carcinogenesis models to investigate contribution of VDD and HC during carcinogenesis via possible modulation of glycolysis. RESULTS: We found that VDD and HC co-exist in OSCC patients, and deregulation of cholesterol and vitamin D levels results in enrichment of genes related to glycolysis. We, then, demonstrated that VDD and HC on their own and together facilitated the formation of larger tumors in 4NQO-induced in vivo cancer models, which are suppressed by glycolysis inhibition. CONCLUSION: We reported collaborative contribution of HC and VDD during oral carcinogenesis, which is mainly carried out via altering energy metabolism in tumor cells.

CASC11 promotes aggressiveness of prostate cancer cells through miR-145/IGF1R axis.

BACKGROUND: Prostate cancer (PCa) is the most common malignancy diagnosed among men after lung cancer in developed countries. Investigation of the underlying molecular mechanisms of PCa is urgently needed in order to develop better therapeutic strategies and to reveal more effective therapeutic targets. In this study, we aimed at exploring the potential functions of CASC11 in association with miR-145 and IGF1R during the malignant progression of PCa cells. METHODS: We initially investigated the oncogenic potential of noncoding members of CASC gene family and analyzed the effects of CASC11 overexpression on proliferation, migration, and colony formation ability of DU145, LNCaP, and PC3 PCa cells. We, then, exprlored the association of CASC11, miR-145, and IGF1R expression and their impacts on PI3K/AKT/mTOR signaling pathway in in vitro models. RESULTS: In silico analysis revealed that of the CASC family only CASC11 showed consistent results considering its differential expression as well as its association with the overall survival of patients. We demonstrated that ectopic overexpression of CASC11 significantly increased the proliferation, colony formation, and migration capacity in all three cell lines. CASC11 overexpression caused suppression of miR-145 and overexpression of IGF1R, leading to activation of PI3K/AKT/mTOR signaling pathway. CONCLUSION: In summary, we found that CASC11 is upregulated in PCa cells and clinical tumor samples in comparison to corresponding controls and revealed that ectopic CASC11 overexpression promotes cellular phenotypes associated with PCa progression through CASC11/miR-145/IGF1R axis.

MicroRNA-145 transcriptionally regulates Semaphorin 3A expression in prostate cancer cells.

Prostate cancer (PCa) is one of the most prevalent cancer types among males. Differential expression of microRNAs is associated with various cancers including PCa. Although mature microRNAs are preferentially located in the cytoplasm, several studies identified mature human microRNAs in purified nuclei and miR-145 has been found to be predominantly expressed in the nuclei of benign tissues compared to tumor lesions. However, the nuclear functions of miR-145 are yet limited. Here, we aimed at investigating the inductive role of miR-145 on the expression of Semaphorin 3A (SEMA3A) in PCa cell lines. To study the regulatory potential of miR-145 in the transcriptional level in PCa, we overexpressed miR-145 in PC3 and DU145 cells, and confirmed its upregulation by quantitative-real-time-PCR. Then we investigated the tumor suppressor potential of miR-145 upon inducing SEMA3A expression using cell viability assay, western blot analysis, Chromatin Immunoprecipitation assay and luciferase reporter assay. Our results revealed that p53, miR-145, and SEMA3A expressions are significantly downregulated in PC3 and DU145 cells compared to nontumorigenic prostate epithelial PNT1a cells. miR-145 overexpression in PCa cells induced the expression of SEMA3A at both messenger RNA and protein levels. Furthermore, increased miR-145 expression enriched RNA Pol-II antibody on the promoter of SEMA3A and induced luciferase activity controlled by SEMA3A promoter. In this study, we showed that the functions of miR-145 are not limited to gene silencing, and found that it may lead to changes in gene expression in the transcriptional level.

Comprehensive in silico analysis for identification of novel candidate target genes, including DHX36, OPA1, and SENP2, located on chromosome 3q in head and neck cancers.

BACKGROUND: Major milestones of head and neck carcinogenesis have been associated with various genetic abnormalities; however, a clear picture of the molecular networks deregulated during the carcinogenesis of head and neck squamous cell carcinoma (HNSC) has not yet completely revealed. METHODS: In this study, we used in silico tools and online data sets to evaluate the underlying reasons for the expressional changes of genes residing within the chromosome 3q and to help understanding their contributions to HNSC carcinogenesis. RESULTS: We found that 13 of 20 most upregulated genes in HNSC are localized to 3q. Further analysis revealed a gene signature consisting of DHX36, OPA1, and SENP2, which showed significant correlation in HNSC samples and potentially be deregulated through similar mechanisms including DNA amplification, transcriptional, and posttranscriptional regulation. CONCLUSIONS: Considering our findings, we suggest DHX36, OPA1, and SENP2 genes as overexpressed in HNSC tumors and that might be concurrently involved in HNSC carcinogenesis, tumor progression, and induction of angiogenic pathways.

The roles of microRNAs in the stemness of oral cancer cells.

Oral cancer (OC), which is the most common form of head and neck cancers, has one of the lowest (~50%) overall 5-year survival rates. The main reasons for this high mortality rate are diagnosis of OC in advanced stages in most patients and spread to distant organs via lymph node metastasis. Many studies have shown that a small population of cells within the tumor plays vital roles in the initiation, progression, and metastasis of the tumor, resistance to chemotherapeutic agents, and recurrence. These cells, identified as cancer stem cells (CSCs), are the main reasons for the failure of current treatment modalities. Deregulated expressions of microRNAs are closely related to tumor prognosis, metastasis and drug resistance. In addition, microRNAs play important roles in regulating the functions of CSCs. Until now, the roles of microRNAs in the acquisition and maintenance of OC stemness have not been elucidated in detail yet. Here in this review, we summarized significant findings and the latest literature to better understand the involvement of CSCs in association with dysregulated microRNAs in oral carcinogenesis. Possible roles of these microRNAs in acquisition and maintenance of CSCs features during OC pathogenesis were summarized.

Mode of action of carboplatin via activating p53/miR-145 axis in head and neck cancers.

OBJECTIVES: In this study, we aimed at investigating the expressions of miR-145 and its well-characterized direct targets on carboplatin treatment. STUDY DESIGN: Laboratory study. METHODS: The effect of carboplatin and miR-145 on the proliferative capacity of head and neck squamous cell carcinoma cells was evaluated using Cell Viability Detection Kit-8. Expressions of miR-145 and its targets were evaluated using quantitative real-time polymerase chain reaction on carboplatin treatment and p53 inhibition. Western blot was used to measure the levels of p53 and its acetylated versions in cells treated with carboplatin and/or pifithrin-α. RESULTS: We demonstrated that carboplatin induced the expression of miR-145 in a dose-dependent manner and suppressed the expressions of miR-145 direct targets. In addition, we showed that inhibition of p53 by pifithrin-α in carboplatin-treated cells reduced miR-145 expression and reversed the suppression of miR-145 direct targets. CONCLUSIONS: Considering all these findings together, one of the proposed mechanisms of carboplatin to kill cells might be the induction of miR-145 and deregulation of its targets in parallel, via p53 activation, which happens through carboplatin's DNA-damaging property. To the best of our knowledge, these findings are the first to reveal the relationship between carboplatin and miR-145 in cancer cells. LEVEL OF EVIDENCE: NA Laryngoscope, 2019.

ING5 inhibits cancer aggressiveness by inhibiting Akt and activating p53 in prostate cancer.

Prostate cancer (PCa) is one of the most common types of cancer in men. In several recent studies, chromosomal deletions in the q arm of chromosome 2, where ING5 resides within, have been identified in various cancer types including PCa. In this study, we investigate the role of ING5 as a tumor suppressor in PCa. We examined the expression level of ING5 in tissue samples and cell lines using quantitative real-time polymerase chain reaction and western blot analysis. We tested the in vitro tumor suppressor potential of ING5 in PC3 and LNCaP cells stably overexpressing it using cell viability, colony formation, migration, invasion, and apoptosis assays. We then investigated the effects of ING5 on the Akt and p53 signaling using western blot analysis. We show that ING5 is significantly downregulated in PCa tumor tissue samples and cell lines compared with the corresponding controls. In vitro assays demonstrate that ING5 effectively suppresses proliferative, clonogenic, migratory, and invasive potential and induce apoptosis in PCa cells. ING5 may potentially exert its anti-tumor potential by inhibiting AKT and inducing p53 signaling pathways. Our findings demonstrate that ING5 possesses tumor suppressor roles in vitro, pointing its importance during the prostatic carcinogenesis processes.