Roles of mechanosensitive ion channel PIEZO1 in the pathogenesis of brain injury after experimental intracerebral hemorrhage.

Secondary brain injury after intracerebral hemorrhage (ICH) is the main cause of poor prognosis in ICH patients, but the underlying mechanisms remain less known. The involvement of Piezo1 in brain injury after ICH was studied in a mouse model of ICH. ICH was established by injecting autologous arterial blood into the basal ganglia in mice. After vehicle, Piezo1 blocker, GsMTx4, Piezo1 activator, Yoda-1, or together with mannitol (tail vein injection) was injected into the left lateral ventricle of mouse brain, Piezo1 level and the roles of Piezo1 in neuronal injury, brain edema, and neurological dysfunctions after ICH were determined by the various indicated methods. Piezo1 protein level in neurons was significantly upregulated 24 h after ICH in vivo (human and mice). Piezo1 protein level was also dramatically upregulated in HT22 cells (a murine neuron cell line) cultured in vitro 24 h after hemin treatment as an in vitro ICH model. GsMTx4 treatment or together with mannitol significantly downregulated Piezo1 and AQP4 levels, markedly increased Bcl2 level, maintained more neurons alive, considerably restored brain blood flow, remarkably relieved brain edema, substantially decreased serum IL-6 level, and almost fully reversed the neurological dysfunctions at ICH 24 h group mice. In contrast, Yoda-1 treatment achieved the opposite effects. In conclusion, Piezo1 plays a crucial role in the pathogenesis of brain injury after ICH and may be a target for clinical treatment of ICH.

TREM2 Alleviates Subarachnoid Hemorrhage-Induced Brain Injury through Attenuating Neuroinflammation and Programmed Cell Death in Vivo and in Vitro.

BACKGROUND: Apoptosis and pyroptosis are two types of programmed cell death related to the neuroinflammatory reaction after subarachnoid hemorrhage (SAH). Research indicates that triggering receptor expressed on myeloid cells 2 (TREM2) can regulate the SAH-induced inflammatory response. However, whether TREM2 regulates programmed cell death (apoptosis and pyroptosis) remains to be clarified. The purpose of the present study was to investigate the effects of TREM2 on cell death in SAH. METHODS: SAH was induced in adult male C57BL/6J mice by endovascular perforation. An in-vitro cellular model of SAH was established by treating cocultured BV2 microglia and HT22 neuronal cells with oxyhemoglobin. TREM2 overexpression or knockdown was carried out by intraventricular lentivirus injection at 7 d before SAH induction in mice or lentiviral transfection, respectively. Neurobehavioral tests as well as western blot, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), immunofluorescence, Evans blue (EB) staining, Nissl staining, and flow cytometry assays were performed to investigate the neuroprotective role of TREM2 after SAH. RESULTS: After SAH, the TREM2 mRNA and protein levels were elevated in SAH mice, exhibiting a peak at 72 h. TREM2 overexpression improved the SAH-induced neurological deficits in mice, while TREM2 knockdown worsened them. In the brains of mice with TREM2 overexpression, less neuronal death and more neuronal survival were detected at 72 h post SAH. Meanwhile, TREM2 overexpression showed an inhibitory effect on microglial activation, neutrophil infiltration, and the expression of cell death marker proteins. Consistent results were obtained in vitro. CONCLUSIONS: Our research indicates the important role of TREM2 on cell death after SAH, suggesting that targeting TREM2 might be an effective approach for treating SAH.

Brusatol's anticancer activity and its molecular mechanism: a research update.

OBJECTIVE: Brusatol (BT) is a quassinoid compound extracted from Brucea javanica that is a traditional Chinese herbal medicine. Brusatol possesses biological and medical activity, including antitumor, antileukemia, anti-inflammatory, antitrypanosomal, antimalarial, and antitobacco mosaic virus activity. To summarize and discuss the antitumor effects of BT and its mechanisms of actions, we compiled this review by combining the extensive relevant literature and our previous studies. METHODS: We searched and retrieved the papers that reported the pharmacological effects of BT and the mechanism of BT antitumor activity from PubMed until July 2023. KEY FINDINGS: Numerous studies have shown that BT is a unique nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor that acts on various signaling pathways and has good antitumor properties. Brusatol shows great potential in cancer therapy by inhibiting cell proliferation, blocking the cell cycle, promoting tumor cell differentiation, accelerating tumor cell apoptosis, inducing autophagy, suppressing angiogenesis, inhibiting tumor invasion and metastasis, and reversing multidrug resistance. CONCLUSION: This review summarizes recent updates on the antitumor activity and molecular mechanisms of BT and provides references for future development and clinical translation of BT and its derivatives as antitumor drugs.

Tuning Shortwave-Infrared J-aggregates of Aromatic Ring-Fused Aza-BODIPYs by Peripheral Substituents for Combined Photothermal and Photodynamic Therapies at Ultralow Laser Power.

Achieving photothermal therapy (PTT) at ultralow laser power density is crucial for minimizing photo-damage and allowing for higher maximum permissible skin exposure. However, this requires photothermal agents to possess not just superior photothermal conversion efficiency (PCE), but also exceptional near-infrared (NIR) absorptivity. J-aggregates, exhibit a significant redshift and narrower absorption peak with a higher extinction coefficient. Nevertheless, achieving predictable J-aggregates through molecular design remains a challenge. In this study, we successfully induced desirable J-aggregation (λabs max : 968 nm, ϵ: 2.96×105  M-1 cm-1 , λem max : 972 nm, ΦFL : 6.2 %) by tuning electrostatic interactions between π-conjugated molecular planes through manipulating molecular surface electrostatic potential of aromatic ring-fused aza-BODIPY dyes. Notably, by controlling the preparation method for encapsulating dyes into F-127 polymer, we were able to selectively generate H-/J-aggregates, respectively. Furthermore, the J-aggregates exhibited two controllable morphologies: nanospheres and nanowires. Importantly, the shortwave-infrared J-aggregated nanoparticles with impressive PCE of 72.9 % effectively destroyed cancer cells and mice-tumors at an ultralow power density of 0.27 W cm-2 (915 nm). This phototherapeutic nano-platform, which generates predictable J-aggregation behavior, and can controllably form J-/H-aggregates and selectable J-aggregate morphology, is a valuable paradigm for developing photothermal agents for tumor-treatment at ultralow laser power density.

CircRNA Hsa_circ_0120175 Promotes Ovarian Cancer Tumorigenesis and Predicts a Poor Prognosis.

BACKGROUND: Circular RNA is a type of non-coding RNA that is commonly found in eukaryotic genomes. They play an essential role in the biological processes of cell proliferation and cell apoptosis involved in normal development and abnormal tumorigenesis. In this study, we examined whether that the circular RNA GENE hsa_circ_0120175 is substantially expressed in epithelial ovarian cancer, and then explored whether hsa_circ_0120175 plays an important role in the occurrence and development of ovarian cancer. METHODS: A total of 40 patients with ovarian cancer were included in this study, and tissue samples were collected from both ovarian cancer tissues and paracancer tissues. The levels of hsa_circ_0120175 expression were determined using qRT-PCR in both varian cancer cells and tissues. This study assessed the impact of hsa_circ_0120175 on cellular proliferation, migration, and invasion using various in vitro assays with cultured ovarian carcinoma cells. RESULTS: Hsa_circ_0120175 was highly expressed in both human tissues and ovarian cancer cells. In ovarian cancer patients, the expression level of hsa_circ_0120175 was significantly different among The International Federation of Gynecology and Obstetrics (FIGO) stages (p = 0.03), and the difference was statistically significant. Multivariate Cox regression analysis showed that lymph node metastasis was independently related to Overall Survival (OS), and the difference was statistically significant (p = 0.033). In vitro, decreasing hsa_circ_0120175 significantly reduced ovarian carcinoma cell proliferation, migration, and invasion (p < 0.05). CONCLUSIONS: Hsa_circ_0120175 has the potential to serve as a biomarker for diagnosing and treating ovarian carcinoma. This is because it promotes cellular proliferation, migration, and invasion in epithelial ovarian carcinoma.

METTL16 Inhibits the Malignant Progression of Epithelial Ovarian Cancer through the lncRNA MALAT1/ß-Catenin Axis.

Epithelial ovarian cancer (EOC) ranks third in the incidence of gynecological malignancies. m6A methylation as RNA modification plays a crucial role in the evolution, migration, and invasion of various tumors. However, the role of m6A methylation in ovarian cancer (OC) only recently has begun to be appreciated. Therefore, we used various bioinformatic methods to screen the public GEO datasets of epithelial ovarian cancer (EOC) for m6A methylation-related regulators. We identified methyltransferase 16 (METTL16) that was dramatically downregulated in EOC as such a regulator. We also identified metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a known target lncRNA of METTL16, in these five GEO datasets. RT-qPCR and immunohistochemical staining confirmed that compared with the normal ovarian tissues and cells, METTL16 was significantly downregulated, while lncRNA MALAT1 was significantly upregulated, in 30 EOC tissues of our own validation cohorts and EOC cell lines, revealing a negative correlation between METTL16 and lncRNA MALAT1. Moreover, our analysis unveiled a correlation between downregulated METTL16 and the known adverse prognostic factors of EOC patients in our own cohorts. The CCK-8, EdU, scratch wound healing, and transwell invasion assays revealed that METTL16 significantly suppressed the proliferating, migrating, and invading abilities of OC cells. The inhibitory effects of METTL16 on the in vivo tumor growth of EOC cells were measured by subcutaneous tumor formation assay in mice. Furthermore, the RIP, RNA stability assay, western blotting, and cytoimmunofluorescence staining showed that METTL16 hindered the growth of EOC cells through promoting the degradation of MALAT1 by binding that, in turn, upregulates ß-catenin protein and promotes nuclear transport of ß-catenin protein in EOC cells. This study suggests that METTL16 acts as a tumor suppressor gene of EOC by achieving its inhibitory function on the malignant progression of EOC through the METTL16/MALAT1/ß-catenin axis that are new targets for EOC diagnosis and therapy.

A functional crosstalk between the H3K9 methylation writers and their reader HP1 in safeguarding embryonic stem cell identity.

Histone H3 lysine 9 (H3K9) methylation, as a hallmark of heterochromatin, has a central role in cell lineage and fate determination. Although evidence of a cooperation between H3K9 methylation writers and their readers has started to emerge, their actual interplay remains elusive. Here, we show that loss of H3K9 methylation readers, the Hp1 family, causes reduced expression of H3K9 methyltransferases, and that this subsequently leads to the exit of embryonic stem cells (ESCs) from pluripotency and a reciprocal gain of lineage-specific characteristics. Importantly, the phenotypes of Hp1-null ESCs can be rescued by ectopic expression of Setdb1, Nanog, and Oct4. Furthermore, Setdb1 ablation results in loss of ESC identity, which is accompanied by a reduction in the expression of Hp1 genes. Together, our data support a model in which the safeguarding of ESC identity involves the cooperation between the H3K9 methylation writers and their readers.

Efficiently targeted therapy of glioblastoma xenograft via multifunctional biomimetic nanodrugs.

BACKGROUND: Glioblastoma multiforme (GBM) is a fatal malignant primary brain tumor in adults. The therapeutic efficacy of chemotherapeutic drugs is limited due to the blood-brain barrier (BBB), poor drug targeting, and short biological half-lives. Multifunctional biomimetic nanodrugs have great potential to overcome these limitations of chemotherapeutic drugs. METHODS: We synthesized and characterized a biomimetic nanodrug CMS/PEG-DOX-M. The CMS/PEG-DOX-M effectively and rapidly released DOX in U87 MG cells. Cell proliferation and apoptosis assays were examined by the MTT and TUNEL assays. The penetration of nanodrugs through the BBB and anti-tumor efficacy were investigated in the orthotopic glioblastoma xenograft models. RESULTS: We showed that CMS/PEG-DOX-M inhibited cell proliferation of U87 MG cells and effectively induced cell apoptosis of U87 MG cells. Intracranial antitumor experiments showed that free DOX hardly penetrated the BBB, but CMS/PEG-DOX-M effectively reached the orthotopic intracranial tumor through the BBB and significantly inhibited tumor growth. Immunofluorescence staining of orthotopic tumor tissue sections confirmed that nanodrugs promoted apoptosis of tumor cells. This study developed a multimodal nanodrug treatment system with the enhanced abilities of tumor-targeting, BBB penetration, and cancer-specific accumulation of chemotherapeutic drugs by combining chemotherapy and photothermal therapy. It can be used as a flexible and effective GBM treatment system and it may also be used for the treatment of other central nervous systems (CNS) tumors and extracranial tumors.

Inhibition of TRPA1 Attenuates Oxidative Stress-induced Damage After Traumatic Brain Injury via the ERK/AKT Signaling Pathway.

Neuron apoptosis is a feature of secondary injury after traumatic brain injury (TBI). Evidence implies that excess calcium (Ca2+) ions and reactive oxidative species (ROS) play critical roles in apoptosis. In reaction to increased ROS, the anti-oxidative master transcription factor, Transient receptor potential Ankyrin 1 (TRPA1) allows Ca2+ ions to enter cells. However, the effect of TBI on the expression of TRPA1 and the role of TRPA1 in TBI are unclear. In the present study, TBI in the mouse brain was simulated using the weight-drop model. The process of neuronal oxidative stress was simulated in HT22 neuronal cells by treatment with hydrogen peroxide. We found that TRPA1 was significantly upregulated in neurons at 24 h after TBI. Neuronal apoptosis was increased in the in vivo and in vitro models; however, this increase was reduced by the functional inhibition of TRPA1 in both models. After TBI, TRPA1 was upregulated via nuclear factor, erythroid 2 like 2 (Nrf2) in neurons. TRPA1-mediated neuronal apoptosis after TBI might be achieved in part through the CaMKII/AKT/ERK signaling pathway. To sum up, TBI-triggered TRPA1 upregulation in neurons is mediated by Nrf2 and the functional blockade of TRPA1 attenuates neuronal apoptosis and improves neuronal dysfunction, partially mediated through the activation of the calcium/calmodulin dependent protein kinase II (CaMKII) extracellular regulated kinase (ERK)/protein kinase B (AKT) signaling pathway. Our results suggest that functional blockade of TRPA1 might be a promising therapeutic intervention related to ROS and Nrf2 in TBI.

RhoJ facilitates angiogenesis in glioblastoma via JNK/VEGFR2 mediated activation of PAK and ERK signaling pathways.

Glioblastoma (GBM) is a highly vascularized malignant tumor that depends on new blood vessel formation. Small molecules targeting the angiogenic process may be an effective anti-GBM therapeutic strategy. We previously demonstrated that RhoJ promoted the progression and invasion of GBM. RhoJ has also been shown to be expressed in endothelial cells and plays an important role in regulating endothelial cell migration and tumor angiogenesis. Therefore, we aimed to evaluate the role and mechanism of actions of RhoJ in GBM angiogenesis. We analyzed the expression of RhoJ in different grade gliomas and investigated its role in GBM angiogenesis in vivo and in vitro. Furtherly, RNA sequencing (RNA-seq), Western blotting and immunofluorescence were performed to identify the molecular mechanism of RhoJ in regulating endothelial cell behavior and GBM angiogenesis. Here, we found that silencing RhoJ resulted in inhibition of HUVEC cell migration and blood vessel formation. Overexpression of RhoJ promoted the expression of CD31, EpCAM and moesin, suggesting RhoJ facilitated angiogenesis and the malignant progression of GBM. RNA-seq data showed that VEGF/TNF signaling pathway positively regulated RhoJ. The expression levels of RhoJ was upregulated with the stimulation of VEGF, and reduced by the treatment of JNK inhibitor SP600125. It was also found that the activity of PAK-BRAF-ERK was down-regulated upon RhoJ and JNK knockdown. In conclusion, these results suggested that RhoJ plays an essential role in regulating GBM angiogenesis through the JNK/VEGFR2-PAK-ERK signaling pathway and there might exist a VEGF-JNK/ERK-VEGF circuitry. Thus, RhoJ may be a candidate therapeutic target for anti-angiogenesis treatment in GBM.

Identification of an epithelial-mesenchymal transition-related lncRNA prognostic signature for patients with glioblastoma.

Glioblastoma (GBM) is a strikingly heterogeneous and lethal brain tumor with very poor prognosis. LncRNAs play critical roles in the tumorigenesis of GBM through regulation of various cancer-related genes and signaling pathways. Here, we focused on the essential role of EMT and identified 78 upregulated EMT-related genes in GBM through differential expression analysis and Gene set enrichment analysis (GSEA). A total of 301 EMT-related lncRNAs were confirmed in GBM through Spearman correlation analysis and a prognostic signature consisting of seven EMT-related lncRNAs (AC012615.1, H19, LINC00609, LINC00634, POM121L9P, SNHG11, and USP32P3) was established by univariate and multivariate Cox regression analyses. Significantly, Kaplan-Meier analysis and receiver-operating-characteristic (ROC) curve validated the accuracy and efficiency of the signature to be satisfactory. Quantitative real-time (qRT)-PCR assay demonstrated the expression alterations of the seven lncRNAs between normal glial and glioma cell lines. Functional enrichment analysis revealed multiple EMT and metastasis-related pathways were associated with the EMT-related lncRNA prognostic signature. In addition, we observed the degree of immune cell infiltration and immune responses were significantly increased in high-risk subgroup compared with low-risk subgroup. In conclusion, we established an effective and robust EMT-related lncRNA signature which was expected to predict the prognosis and immunotherapy response for GBM patients.

Newly Identified Members of FGFR1 Splice Variants Engage in Cross-talk with AXL/AKT Axis in Salivary Adenoid Cystic Carcinoma.

Adenoid cystic carcinoma (ACC) is the second most common malignancy of the salivary gland. Although characterized as an indolent tumor, ACC often leads to incurable metastatic disease. Patients with ACC respond poorly to currently available therapeutic drugs and factors contributing to the limited response remain unknown. Determining the role of molecular alterations frequently occurring in ACC may clarify ACC tumorigenesis and advance the development of effective treatment strategies. Applying Splice Expression Variant Analysis and outlier statistics on RNA sequencing of primary ACC tumors and matched normal salivary gland tissues, we identified multiple alternative splicing events (ASE) of genes specific to ACC. In ACC cells and patient-derived xenografts, FGFR1 was a uniquely expressed ASE. Detailed PCR analysis identified three novel, truncated, intracellular domain-lacking FGFR1 variants (FGFR1v). Cloning and expression analysis suggest that the three FGFR1v are cell surface proteins, that expression of FGFR1v augmented pAKT activity, and that cells became more resistant to pharmacologic FGFR1 inhibitor. FGFR1v-induced AKT activation was associated with AXL function, and inhibition of AXL activity in FGFR1v knockdown cells led to enhanced cytotoxicity in ACC. Moreover, cell killing effect was increased by dual inhibition of AXL and FGFR1 in ACC cells. This study demonstrates that these previously undescribed FGFR1v cooperate with AXL and desensitize cells to FGFR1 inhibitor, which supports further investigation into combined FGFR1 and AXL inhibition as an effective ACC therapy.This study identifies several FGFR1 variants that function through the AXL/AKT signaling pathway independent of FGF/FGFR1, desensitizing cells to FGFR1 inhibitor suggestive of a potential resistance mechanism in ACC. SIGNIFICANCE: This study identifies several FGFR1 variants that function through the AXL/AKT signaling pathway independent of FGF/FGFR1, desensitizing cells to FGFR1 inhibitor, suggestive of a potential resistance mechanism in ACC.

Targeted Deletion of Interleukin-6 in a Mouse Model of Chronic Inflammation Demonstrates Opposing Roles in Aging: Benefit and Harm.

Chronic inflammation (CI) in older adults is associated with reduced health span and life span. Interleukin-6 (IL-6) is one CI marker that is strongly associated with adverse health outcomes and mortality in aging. We have previously characterized a mouse model of frailty and chronic inflammatory pathway activation (IL-10tm/tm, IL-10 KO) that demonstrates the upregulation of numerous proinflammatory cytokines, including IL-6. We sought to identify a more specific role for IL-6 within the context of CI and aging and developed a mouse with targeted deletion of both IL-10 and IL-6 (IL-10tm/tm/IL-6tm/tm, DKO). Phenotypic characteristics, cytokine measurements, cardiac myocardial oxygen consumption, physical function, and survival were measured in DKO mice and compared to age- and gender-matched IL-10 KO and wild-type mice. Our findings demonstrate that selective knockdown of IL-6 in a frail mouse with CI resulted in the reversal of some of the CI-associated changes. We observed increased protective mitochondrial-associated lipid metabolites, decreased cardiac oxaloacetic acid, improved myocardial oxidative metabolism, and better short-term functional performance in DKO mice. However, the DKO mice also demonstrated higher mortality. This work shows the pleiotropic effects of IL-6 on aging and frailty.

Chemical genomic analysis of GPR35 signaling.

GPR35, a family A orphan G protein-coupled receptor, has been implicated in inflammatory, neurological, and cardiovascular diseases. However, not much is known about the signaling and functions of GPR35. We performed a label-free kinome short hairpin RNA screen and identified a putative signaling network of GPR35 in HT-29 cells, some of which was validated using gene expression, biochemical and cellular assays. The results showed that GPR35 induced hypoxia-inducible factor 1α, and was involved in synaptic transmission, sensory perception, the immune system, and morphogenetic processes. Collectively, our data suggest that GPR35 may play an important role in response to hypoxic stress and be a potential target for the treatment of inflammatory, cardiovascular, and neurological disorders.

Identification of methylated genes in salivary gland adenoid cystic carcinoma xenografts using global demethylation and methylation microarray screening.

Salivary gland adenoid cystic carcinoma (ACC) is a rare head and neck malignancy without molecular biomarkers that can be used to predict the chemotherapeutic response or prognosis of ACC. The regulation of gene expression of oncogenes and tumor suppressor genes (TSGs) through DNA promoter methylation may play a role in the carcinogenesis of ACC. To identify differentially methylated genes in ACC, a global demethylating agent, 5-aza-2'-deoxycytidine (5-AZA) was utilized to unmask putative TSG silencing in ACC xenograft models in mice. Fresh xenografts were passaged, implanted in triplicate in mice that were treated with 5-AZA daily for 28 days. These xenografts were then evaluated for genome-wide DNA methylation patterns using the Illumina Infinium HumanMethylation27 BeadChip array. Validation of the 32 candidate genes was performed by bisulfite sequencing (BS-seq) in a separate cohort of 6 ACC primary tumors and 6 normal control salivary gland tissues. Hypermethylation was identified in the HCN2 gene promoter in all 6 control tissues, but hypomethylation was found in all 6 ACC tumor tissues. Quantitative validation of HCN2 promoter methylation level in the region detected by BS-seq was performed in a larger cohort of primary tumors (n=32) confirming significant HCN2 hypomethylation in ACCs compared with normal samples (n=10; p=0.04). HCN2 immunohistochemical staining was performed on an ACC tissue microarray. HCN2 staining intensity and H-score, but not percentage of the positively stained cells, were significantly stronger in normal tissues than those of ACC tissues. With our novel screening and sequencing methods, we identified several gene candidates that were methylated. The most significant of these genes, HCN2, was actually hypomethylated in tumors. However, promoter methylation status does not appear to be a major determinant of HCN2 expression in normal and ACC tissues. HCN2 hypomethylation is a biomarker of ACC and may play an important role in the carcinogenesis of ACC.

Whole-Genome Sequencing of Salivary Gland Adenoid Cystic Carcinoma.

Adenoid cystic carcinomas (ACC) of the salivary glands are challenging to understand, treat, and cure. To better understand the genetic alterations underlying the pathogenesis of these tumors, we performed comprehensive genome analyses of 25 fresh-frozen tumors, including whole-genome sequencing and expression and pathway analyses. In addition to the well-described MYB-NFIB fusion that was found in 11 tumors (44%), we observed five different rearrangements involving the NFIB transcription factor gene in seven tumors (28%). Taken together, NFIB translocations occurred in 15 of 25 samples (60%, 95% CI, 41%-77%). In addition, mRNA expression analysis of 17 tumors revealed overexpression of NFIB in ACC tumors compared with normal tissues (P = 0.002). There was no difference in NFIB mRNA expression in tumors with NFIB fusions compared with those without. We also report somatic mutations of genes involved in the axonal guidance and Rho family signaling pathways. Finally, we confirm previously described alterations in genes related to chromatin regulation and Notch signaling. Our findings suggest a separate role for NFIB in ACC oncogenesis and highlight important signaling pathways for future functional characterization and potential therapeutic targeting.

TMEM16A/ANO1 is differentially expressed in HPV-negative versus HPV-positive head and neck squamous cell carcinoma through promoter methylation.

Head and neck squamous cell carcinoma (HNSCC) has a variety of causes. Recently, the human papilloma virus (HPV) has been implicated in the rising incidence of oropharyngeal cancer and has led to variety of studies exploring the differences between HPV-positive and HPV-negative HNSCC. The calcium-activated chloride channel TMEM16A is overexpressed in a variety of cancers, including HNSCC, but whether or not it plays different roles in HPV-positive and HPV-negative HNSCC is unknown. Here, we demonstrate that TMEM16A is preferentially overexpressed in HPV-negative HNSCC and that this overexpression of TMEM16A is associated with decreased patient survival. We also show that TMEM16A expression is decreased in HPV-positive HNSCC at the DNA, RNA, and protein levels in patient samples as well as cell lines. We demonstrate that the lower levels of TMEM16A expression in HPV-positive tumors can be attributed to both a combination of copy number alteration and promoter methylation at the DNA level. Additionally, our cellular data show that HPV-negative cell lines are more dependent on TMEM16A for survival than HPV-positive cell lines. Therefore, we suspect that the down-regulation of TMEM16A in HPV-positive HNSCC makes TMEM16A a poor therapeutic target in HPV-positive HNSCC, but a potentially useful target in HPV-negative HNSCC.

Epigenetic screening of salivary gland mucoepidermoid carcinoma identifies hypomethylation of CLIC3 as a common alteration.

OBJECTIVES: The role of promoter methylation in the development of mucoepidermoid carcinoma (MEC) has not been fully explored. In this study, we investigated the epigenetic landscape of MEC. METHODS: The Illumina HumanMethylation27 BeadChip array and differential methylation analysis were utilized to screen for epigenetic alterations in 14 primary MEC tumors and 14 matched normal samples. Bisulfite sequencing was used to validate these results, with subsequent quantitative Methylation-Specific PCR (qMSP) to validate chloride intracellular channel protein 3 (CLIC3) in a separate cohort. Furthermore, CLIC3 immunohistochemical (IHC) staining was performed in another separate cohort of MEC. Finally, clinical and pathological characteristics were statistically analyzed for correlation with methylation status of CLIC3 and CLIC3 IHC H-scores by Wilcoxon rank sum, Kruskall-Wallis, and X(2) test tests. RESULTS: We obtained 6 significantly differentially methylated gene candidates demonstrating significant promoter hyper- or hypo-methylation from the array data. Using bisulfite sequencing, we found one gene, CLIC3, which showed differential methylation between MEC tumor and normal samples in a small validation cohort. qMSP analysis of the CLIC3 promoter in a separate validation set showed significantly lower methylation level in tumor than in normal. The level of CLIC3 methylation in MECs was not statistically correlated with clinical or pathological characteristics. However, IHC staining intensity and distribution of CLIC3 were significantly increased in MECs, compared with those of normal salivary gland tissues. CONCLUSIONS: Hypomethylation of CLIC3 promoter and its overexpression are significant events in MEC. Its functional role and potential therapeutic utility in MEC are worthy of further exploration.

MYB rearrangement and clinicopathologic characteristics in head and neck adenoid cystic carcinoma.

OBJECTIVES: Salivary gland adenoid cystic carcinoma (ACC) is rare, aggressive, and challenging to treat. Many ACCs have a t(6;9) chromosomal translocation resulting in a MYB-NFIB fusion gene, but the clinical significance is unclear. The purposes of this study were to describe the clinicopathologic factors impacting survival and to determine the prevalence and clinical significance of MYB-NFIB fusion. STUDY DESIGN: Case series. METHODS: Medical records of patients treated for ACC of the head and neck from 1974 to 2011 were reviewed and clinicopathologic data recorded. Fluorescence in situ hybridization (FISH) was used to detect MYB rearrangement in archival tumor tissue as a marker of MYB-NFIB fusion. RESULTS: One hundred fifty-eight patients were included, with median follow-up 75.1 months. Median overall survival was 171.5 months (95% confidence interval [CI] = 131.9-191.6), and median disease-free survival was 112.0 months (95% CI = 88.7-180.4). Advanced stage was associated with decreased overall survival (adjusted ptrend < 0.001), and positive margins were associated with decreased disease-free survival (adjusted hazard ratio [aHR] = 8.80, 95% CI = 1.25-62.12, P = 0.029). Ninety-one tumors were evaluable using FISH, and 59 (65%) had evidence of a MYB-NFIB fusion. MYB-NFIB positive tumors were more likely than MYB-NFIB negative tumors to originate in minor salivary glands (adjusted prevalence ratios = 1.51, 95% CI = 1.07-2.12, P = 0.019). MYB-NFIB tumor status was not significantly associated with disease-free or overall survival (hazard ratio [HR] = 1.53, 95% CI = 0.77-3.02, P = 0.22 and HR = 0.91, 95% CI = 0.46-1.83, P = 0.80, respectively, for MYB-NFIB positive compared with MYB-NFIB negative tumors). CONCLUSION: Stage and margin status were important prognostic factors for ACC. Tumors with evidence of MYB-NFIB fusion were more likely to originate in minor salivary glands, but MYB-NFIB tumor status was not significantly associated with prognosis. LEVEL OF EVIDENCE: 4.

The TGFß-miR200-MIG6 pathway orchestrates the EMT-associated kinase switch that induces resistance to EGFR inhibitors.

Although specific mutations in the tyrosine kinase domain of epidermal growth factor receptor (EGFR) identify tumors that are responsive to EGFR tyrosine kinase inhibitors (TKI), these genetic alterations are present in only a minority of patients. Patients with tumors expressing wild-type EGFR lack reliable predictive markers of their clinical response to EGFR TKIs. Although epithelial-mesenchymal transition (EMT) has been inversely correlated with the response of cancers to EGFR-targeted therapy, the precise molecular mechanisms underlying this association have not been defined and no specific EMT-associated biomarker of clinical benefit has been identified. Here, we show that during transforming growth factor ß (TGFß)-mediated EMT, inhibition of the microRNAs 200 (miR200) family results in upregulated expression of the mitogen-inducible gene 6 (MIG6), a negative regulator of EGFR. The MIG6-mediated reduction of EGFR occurs concomitantly with a TGFß-induced EMT-associated kinase switch of tumor cells to an AKT-activated EGFR-independent state. In a panel of 25 cancer cell lines of different tissue origins, we find that the ratio of the expression levels of MIG6 and miR200c is highly correlated with EMT and resistance to erlotinib. Analyses of primary tumor xenografts of patient-derived lung and pancreatic cancers carrying wild-type EGFR showed that the tumor MIG6(mRNA)/miR200 ratio was inversely correlated with response to erlotinib in vivo. Our data demonstrate that the TGFß-miR200-MIG6 network orchestrates the EMT-associated kinase switch that induces resistance to EGFR inhibitors, and identify a low ratio of MIG6 to miR200 as a promising predictive biomarker of the response of tumors to EGFR TKIs.