High-resolution mapping of the 11q13 amplicon and identification of a gene, TAOS1, that is amplified and overexpressed in oral cancer cells

FADD Functions as an Oncogene in Chr11q13.3-Amplified Head and Neck Squamous Cell Carcinoma

Chromosomal 11q13.3 amplification is the most common gene copy-number variation event in head and neck squamous cell carcinoma (HNSCC) that corresponds with poor prognosis. Although cyclin D1, a G1/S phase cell-cycle regulatory protein at this locus, is considered as a key driver of malignant progression, further exploration is needed to develop more effective targets for cases with this amplification. Using CRISPR-based gene knockout screening of genes located in chr11q13.3, we found that loss of the gene encoding the Fas-associated death domain (FADD) protein, a well-recognized adapter to caspase-8 that induces cell apoptosis, significantly reduced cancer cell proliferation. FADD expression was elevated in chr11q13.3-amplified tumors and correlated with poor prognosis. RNA sequencing, mass spectrometry, and proteomics analyses revealed a direct relationship between FADD and the DNA helicase MCM5 in the S phase. FADD and cyclin D1 acted at different stages of the cell cycle to synergistically induce proliferation, and caspase-8 deficiency was required for the oncogenic activity of FADD. In a patient-derived xenograft model with chr11q13.3 amplification, combined administration of the DNA helicase complex inhibitor and CDK4/6 inhibitor effectively curtailed tumor growth. Overall, this study identified a nonclassic oncogenic role for FADD in mediating tumor progression in HNSCC and provided a feasible treatment option for patients with chr11q13.3 amplification. Significance: FADD promotes progression of tumors with chr11q13.3 amplification by binding to the DNA helicase complex, which can be targeted in combination with cyclin D1 as a viable therapeutic strategy for HNSCC patients.

ANO1: central role and clinical significance in non-neoplastic and neoplastic diseases

Anoctamin 1 (ANO1), also known as TMEM16A, is a multifunctional protein that serves as a calcium-activated chloride channel (CaCC). It is ubiquitously expressed across various tissues, including epithelial cells, smooth muscle cells, and neurons, where it is integral to physiological processes such as epithelial secretion, smooth muscle contraction, neural conduction, and cell proliferation and migration. Dysregulation of ANO1 has been linked to the pathogenesis of numerous diseases. Extensive research has established its involvement in non-neoplastic conditions such as asthma, hypertension, and gastrointestinal (GI) dysfunction. Moreover, ANO1 has garnered significant attention for its role in the development and progression of cancers, including head and neck cancer, breast cancer, and lung cancer, where its overexpression correlates with increased tumor growth, metastasis, and poor prognosis. Additionally, ANO1 regulates multiple signaling pathways, including the epidermal growth factor receptor (EGFR) pathway, the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway, and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway, among others. These pathways are pivotal in regulating cell proliferation, migration, and invasion. Given its central role in these processes, ANO1 has emerged as a promising diagnostic biomarker and therapeutic target. Recent advancements in ANO1 research have highlighted its potential in disease diagnosis and treatment. Strategies targeting ANO1, such as small molecule modulators or gene-silencing techniques, have shown preclinical promise in both non-neoplastic and neoplastic diseases. This review explores the latest findings in ANO1 research, focusing on its mechanistic involvement in disease progression, its regulation, and its therapeutic potential. Modulating ANO1 activity may offer novel therapeutic strategies for effectively treating ANO1-associated diseases.

Liprin-α1 contributes to oncogenic MAPK signaling by counteracting ERK activity

PTPRF interacting protein alpha 1 (PPFIA1) encodes for liprin-α1, a member of the leukocyte common antigen-related protein tyrosine phosphatase (LAR-RPTPs)-interacting protein family. Liprin-α1 localizes to adhesive and invasive structures in the periphery of cancer cells, where it modulates migration and invasion in head and neck squamous cell carcinoma (HNSCC) and breast cancer. To study the possible role of liprin-α1 in anticancer drug responses, we screened a library of oncology compounds in cell lines with high endogenous PPFIA1 expression. The compounds with the highest differential responses between high PPFIA1-expressing and silenced cells across cell lines were inhibitors targeting mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinases (ERK) signaling. KRAS proto-oncogene, GTPase (KRAS)-mutated MDA-MB-231 cells were more resistant to trametinib upon PPFIA1 knockdown compared with control cells. In contrast, liprin-α1-depleted HNSCC cells with low RAS activity showed a context-dependent response to MEK/ERK inhibitors. Importantly, we showed that liprin-α1 depletion leads to increased p-ERK1/2 levels in all our studied cell lines independent of KRAS mutational status, suggesting a role of liprin-α1 in the regulation of MAPK oncogenic signaling. Furthermore, liprin-α1 depletion led to more pronounced redistribution of RAS proteins to the cell membrane. Our data suggest that liprin-α1 is an important contributor to oncogenic RAS/MAPK signaling, and the status of liprin-α1 may assist in predicting drug responses in cancer cells in a context-dependent manner.

Cu2+-doped zeolitic imidazolate frameworks and gold nanoparticle (AuNPs@ZIF-8/Cu) nanocomposites enable label-free and highly sensitive electrochemical detection of oral cancer-related biomarkers

It is of great significance to accurately and sensitively detect oral cancer-related biomarkers (ORAOV 1) for the early diagnosis of oral cancer. Present here is a novel electrochemical biosensor based on Cu2+-doped zeolitic imidazolate frameworks and gold nanoparticle (AuNPs@ZIF-8/Cu) nanocomposites and a one-step strand displacement reaction for label-free, simple and sensitive detection of ORAOV 1 in saliva. It is worth noting that AuNPs@ZIF-8/Cu nanocomposites show large electrochemically effective surface area, good electrical conductivity and electrocatalytic activity due to the synergistic effect of metal nanoparticles (MNPs) and ZIF-8. Consequently, the newly developed electrochemical sensor displays a wide linear range of 0.1-104 pM and a low limit of detection (LOD) of 63 fM. Meanwhile, the electrochemical biosensor can distinguish single base mismatch. The relative standard deviation (RSD) of intra-assays and inter-assays is 1.46% and 1.76%, respectively, and the peak current values decline by 9.20% with a RSD value of 1.35% after being stored at 4 °C for 7 days, suggesting that the newly designed electrochemical sensor exhibits good selectivity, reproducibility and stability to detect ORAOV 1. More importantly, this novel electrochemical sensor is found to be applicable for detecting ORAOV 1 in human saliva samples with a satisfactory result. The RSD values range from 1.15% to 1.77%, and the recoveries range from 95.46% to 112.98%.

Alternative Splicing Landscape of Head and Neck Squamous Cell Carcinoma

Head and neck malignancies are a significant global health concern, with head and neck squamous cell carcinoma (HNSCC) being the sixth most common cancer worldwide accounting for > 90% of cases. In recent years, there has been growing recognition of the potential role of alternative splicing (AS) in the etiology of cancer. Increasing evidence suggests that AS is associated with various aspects of cancer progression, including tumor occurrence, invasion, metastasis, and drug resistance. Additionally, AS is involved in shaping the tumor microenvironment, which plays a crucial role in tumor development and response to therapy. AS can influence the expression of factors involved in angiogenesis, immune response, and extracellular matrix remodeling, all of which contribute to the formation of a supportive microenvironment for tumor growth. Exploring the mechanism of AS events in HNSCC could provide insights into the development and progression of this cancer, as well as its interaction with the tumor microenvironment. Understanding how AS contributes to the molecular changes in HNSCC cells and influences the tumor microenvironment could lead to the identification of new therapeutic targets. Targeted chemotherapy and immunotherapy strategies tailored to the specific AS patterns in HNSCC could potentially improve treatment outcomes and reduce side effects. This review explores the concept, types, processes, and technological advancements of AS, focusing on its role in the initiation, progression, treatment, and prognosis of HNSCC.

Inhibitory effect of daidzein on the calcium-activated chloride channel TMEM16A and its anti-lung adenocarcinoma activity

TMEM16A is highly expressed in a variety of tumor cells and is involved in the growth and metastasis of malignancies. It has been established that down-regulation of TMEM16A expression or functional activity can inhibit tumor cells growth. However, there is a lack of targeted inhibitors with high efficiency and low toxicity. Here, we identified a novel inhibitor daidzein from dozens of natural product molecules. Whole-cell patch clamp data indicated that daidzein inhibits TMEM16A channel in a dose-dependent manner, with IC50 of 1.39 ± 0.59 μM. Western blot result showed that daidzein can also reduce the expression of TMEM16A protein in LA795 cells. These results indicated that the inhibitory effects of daidzein exert on TMEM16A in two ways, both inhibiting TMEM16A current and decreasing its protein expression. In addition, the putative binding sites of daidzein on TMEM16A are G608, G628, and K839 through molecular docking. Moreover, daidzein concentration-dependently reduced cell viability and cell migration, causing G1/S cell cycle arrest in vitro. It was also confirmed that daidzein can effectively inhibit the growth of LA795 lung adenocarcinoma cells implanted nude mice in vivo. In conclusion, daidzein can be used as a lead compound for the development of therapeutic drugs for lung adenocarcinoma.

Three sesquiterpene lactones suppress lung adenocarcinoma by blocking TMEM16A-mediated Ca2+-activated Cl- channels

Transmembrane protein TMEM16A, which encodes calcium-activated chloride channel has been implicated in tumorigenesis. Overexpression of TMEM16A is associated with poor prognosis and low overall survival in multiple cancers including lung adenocarcinoma, making it a promising biomarker and therapeutic target. In this study, three structure-related sesquiterpene lactones (mecheliolide, costunolide and dehydrocostus lactone) were extracted from the traditional Chinese medicine Aucklandiae Radix and identified as novel TMEM16A inhibitors with comparable inhibitory effects. Their effects on the proliferation and migration of lung adenocarcinoma cells were examined. Whole-cell patch clamp experiments showed that these sesquiterpene lactones potently inhibited recombinant TMEM16A currents in a concentration-dependent manner. The half-maximal concentration (IC50) values for three tested sesquiterpene lactones were 29.9 ± 1.1 μM, 19.7 ± 0.4 μM, and 24.5 ± 2.1 μM, while the maximal effect (Emax) values were 100.0% ± 2.8%, 85.8% ± 0.9%, and 88.3% ± 4.6%, respectively. These sesquiterpene lactones also significantly inhibited the endogenous TMEM16A currents and proliferation, and migration of LA795 lung cancer cells. These results demonstrate that mecheliolide, costunolide and dehydrocostus lactone are novel TMEM16A inhibitors and potential candidates for lung adenocarcinoma therapy.

FADS2 function at the major cancer hotspot 11q13 locus alters fatty acid metabolism in cancer

Dysregulation of fatty acid metabolism and de novo lipogenesis is a key driver of several cancer types through highly unsaturated fatty acid (HUFA) signaling precursors such as arachidonic acid. The human chromosome 11q13 locus has long been established as the most frequently amplified in a variety of human cancers. The fatty acid desaturase genes (FADS1, FADS2 and FADS3) responsible for HUFA biosynthesis localize to the 11q12-13.1 region. FADS2 activity is promiscuous, catalyzing biosynthesis of several unsaturated fatty acids by Δ6, Δ8, and Δ4 desaturation. Our main aim here is to review known and putative consequences of FADS2 dysregulation due to effects on the 11q13 locus potentially driving various cancer types. FADS2 silencing causes synthesis of sciadonic acid (5Z,11Z,14Z-20:3) in MCF7 cells and breast cancer in vivo. 5Z,11Z,14Z-20:3 is structurally identical to arachidonic acid (5Z,8Z,11Z,14Z-20:4) except it lacks the internal Δ8 double bond required for prostaglandin and leukotriene synthesis, among other eicosanoids. Palmitic acid has substrate specificity for both SCD and FADS2. Melanoma, prostate, liver and lung cancer cells insensitive to SCD inhibition show increased FADS2 activity and sapienic acid biosynthesis. Elevated serum mead acid levels found in hepatocellular carcinoma patients suggest an unsatisfied demand for arachidonic acid. FADS2 circular RNAs are at high levels in colorectal and lung cancer tissues. FADS2 circular RNAs are associated with shorter overall survival in colorectal cancer patients. The evidence thusfar supports an effort for future research on the role of FADS2 as a tumor suppressor in a range of neoplastic disorders.

Cytosolic iron-sulfur protein assembly system identifies clients by a C-terminal tripeptide

The eukaryotic cytosolic Fe-S protein assembly (CIA) machinery inserts iron-sulfur (Fe-S) clusters into cytosolic and nuclear proteins. In the final maturation step, the Fe-S cluster is transferred to the apo-proteins by the CIA-targeting complex (CTC). However, the molecular recognition determinants of client proteins are unknown. We show that a conserved [LIM]-[DES]-[WF]-COO- tripeptide is present at the C-terminus of more than a quarter of clients or their adaptors. When present, this targeting complex recognition (TCR) motif is necessary and sufficient for binding to the CTC in vitro and for directing Fe-S cluster delivery in vivo. Remarkably, fusion of this TCR signal enables engineering of cluster maturation on a nonnative protein via recruitment of the CIA machinery. Our study advances our understanding of Fe-S protein maturation and paves the way for bioengineering novel pathways containing Fe-S enzymes.

TMEM16A partners with mTOR to influence pathways of cell survival, proliferation, and migration in cholangiocarcinoma

Expression of transmembrane protein 16 A (TMEM16A), a calcium activated chloride channel, is elevated in some human cancers and impacts tumor cell proliferation, metastasis, and patient outcome. Evidence presented here uncovers a molecular synergy between TMEM16A and mechanistic/mammalian target of rapamycin (mTOR), a serine-threonine kinase that is known to promote cell survival and proliferation in cholangiocarcinoma (CCA), a lethal cancer of the secretory cells of bile ducts. Analysis of gene and protein expression in human CCA tissue and CCA cell line detected elevated TMEM16A expression and Cl- channel activity. The Cl- channel activity of TMEM16A impacted the actin cytoskeleton and the ability of cells to survive, proliferate, and migrate as revealed by pharmacological inhibition studies. The basal activity of mTOR, too, was elevated in the CCA cell line compared with the normal cholangiocytes. Molecular inhibition studies provided further evidence that TMEM16A and mTOR were each able to influence the regulation of the other's activity or expression respectively. Consistent with this reciprocal regulation, combined TMEM16A and mTOR inhibition produced a greater loss of CCA cell survival and migration than their individual inhibition alone. Together these data reveal that the aberrant TMEM16A expression and cooperation with mTOR contribute to a certain advantage in CCA.NEW & NOTEWORTHY This study points to the dysregulation of transmembrane protein 16 A (TMEM16A) expression and activity in cholangiocarcinoma (CCA), the inhibition of which has functional consequences. Dysregulated TMEM16A exerts an influence on the regulation of mechanistic/mammalian target of rapamycin (mTOR) activity. Moreover, the reciprocal regulation of TMEM16A by mTOR demonstrates a novel connection between these two protein families. These findings support a model in which TMEM16A intersects the mTOR pathway to regulate cell cytoskeleton, survival, proliferation, and migration in CCA.

The Way to Malignant Transformation: Can Epigenetic Alterations Be Used to Diagnose Early-Stage Head and Neck Cancer?

Identifying and treating tumors early is the key to secondary prevention in cancer control. At present, prevention of oral cancer is still challenging because the molecular drivers responsible for malignant transformation of the 11 clinically defined oral potentially malignant disorders are still unknown. In this review, we focused on studies that elucidate the epigenetic alterations demarcating malignant and nonmalignant epigenomes and prioritized findings from clinical samples. Head and neck included, the genomes of many cancer types are largely hypomethylated and accompanied by focal hypermethylation on certain specific regions. We revisited prior studies that demonstrated that sufficient uptake of folate, the primary dietary methyl donor, is associated with oral cancer reduction. As epigenetically driven phenotypic plasticity, a newly recognized hallmark of cancer, has been linked to tumor initiation, cell fate determination, and drug resistance, we discussed prior findings that might be associated with this hallmark, including gene clusters (11q13.3, 19q13.43, 20q11.2, 22q11-13) with great potential for oral cancer biomarkers, and successful examples in screening early-stage nasopharyngeal carcinoma. Although one-size-fits-all approaches have been shown to be ineffective in most cancer therapies, the rapid development of epigenome sequencing methods raises the possibility that this nonmutagenic approach may be an exception. Only time will tell.

The Structural Dynamics, Complexity of Interactions, and Functions in Cancer of Multi-SAM Containing Proteins

SAM domains are crucial mediators of diverse interactions, including those important for tumorigenesis or metastasis of cancers, and thus SAM domains can be attractive targets for developing cancer therapies. This review aims to explore the literature, especially on the recent findings of the structural dynamics, regulation, and functions of SAM domains in proteins containing more than one SAM (multi-SAM containing proteins, MSCPs). The topics here include how intrinsic disorder of some SAMs and an additional SAM domain in MSCPs increase the complexity of their interactions and oligomerization arrangements. Many similarities exist among these MSCPs, including their effects on cancer cell adhesion, migration, and metastasis. In addition, they are all involved in some types of receptor-mediated signaling and neurology-related functions or diseases, although the specific receptors and functions vary. This review also provides a simple outline of methods for studying protein domains, which may help non-structural biologists to reach out and build new collaborations to study their favorite protein domains/regions. Overall, this review aims to provide representative examples of various scenarios that may provide clues to better understand the roles of SAM domains and MSCPs in cancer in general.

ANO4 Expression Is a Potential Prognostic Biomarker in Non-Metastasized Clear Cell Renal Cell Carcinoma

Background: Over the past decade, transcriptome profiling has elucidated many pivotal pathways involved in oncogenesis. However, a detailed comprehensive map of tumorigenesis remains an enigma to solve. Propelled research has been devoted to investigating the molecular drivers of clear cell renal cell carcinoma (ccRCC). To add another piece to the puzzle, we evaluated the role of anoctamin 4 (ANO4) expression as a potential prognostic biomarker in non-metastasized ccRCC. Methods: A total of 422 ccRCC patients with the corresponding ANO4 expression and clinicopathological data were obtained from The Cancer Genome Atlas Program (TCGA). Differential expression across several clinicopathological variables was performed. The Kaplan-Meier method was used to assess the impact of ANO4 expression on the overall survival (OS), progression-free interval (PFI), disease-free interval (DFI), and disease-specific survival (DSS). Univariate and multivariate Cox logistic regression analyses were conducted to identify independent factors modulating the aforementioned outcomes. Gene set enrichment analysis (GSEA) was used to discern a set of molecular mechanisms involved in the prognostic signature. Tumor immune microenvironment was estimated using xCell. Results: ANO4 expression was upregulated in tumor samples compared to normal kidney tissue. Albeit the latter finding, low ANO4 expression is associated with advanced clinicopathological variables such as tumor grade, stage, and pT. In addition, low ANO4 expression is linked to shorter OS, PFI, and DSS. Multivariate Cox logistic regression analysis identified ANO4 expression as an independent prognostic variable in OS (HR: 1.686, 95% CI: 1.120-2.540, p = 0.012), PFI (HR: 1.727, 95% CI: 1.103-2.704, p = 0.017), and DSS (HR: 2.688, 95% CI: 1.465-4.934, p = 0.001). GSEA identified the following pathways to be enriched within the low ANO4 expression group: epithelial-mesenchymal transition, G2-M checkpoint, E2F targets, estrogen response, apical junction, glycolysis, hypoxia, coagulation, KRAS, complement, p53, myogenesis, and TNF-α signaling via NF-κB pathways. ANO4 expression correlates significantly with monocyte (ρ = -0.1429, p = 0.0033) and mast cell (ρ = 0.1598, p = 0.001) infiltration. Conclusions: In the presented work, low ANO4 expression is portrayed as a potential poor prognostic factor in non-metastasized ccRCC. Further experimental studies should be directed to shed new light on the exact molecular mechanisms involved.

Significance of Anoctamin 6 in progression and prognostic prediction of gastric adenocarcinoma

BACKGROUND

Gastric cancer is one of the most lethal malignancies worldwide with surgery as the only curative therapy. However, postoperative overall survival of gastric cancer is far from satisfactory although significant improvement has been made in adjuvant therapies. Gastric cancer is characterized as highly heterogeneous and illustrating the molecular mechanisms is invaluable for both identification of novel prognostic biomarkers and development of therapeutic drugs. Here we aimed to investigate the participation of Anoctamin 6 (ANO6) in gastric adenocarcinoma.

METHODS

Immunohistochemical (IHC) staining was used to explore the expression pattern of ANO6 in tumor tissues from gastric adenocarcinoma patients (n=108). Clinicopathological data was subjected to Kaplan-Meier survival and Cox multivariate analyses to evaluate prognostic predictors. Overexpression and silencing procedures were performed on gastric cancer cell lines to investigate the functional mechanisms of ANO6 in regulating tumor development.

RESULTS

Higher ANO6 expression showed a positive correlation with advanced tumor stage of gastric cancer. Univariate and multivariate analyses revealed that ANO6 was an independent prognostic factor for overall survival of gastric cancer. An in vitro study demonstrated that ANO6 can promote cell proliferation while silencing ANO6 significantly downregulated cell viability.

CONCLUSION

High ANO6 expression in gastric cancer indicates poor clinical outcomes, and ANO6 may act as a potential target for novel therapy development targeting gastric cancer.

Role of ANO1 in tumors and tumor immunity

Dysregulation of gene amplification, cell-signaling-pathway transduction, epigenetic and transcriptional regulation, and protein interactions drives tumor-cell proliferation and invasion, while ion channels also play an important role in the generation and development of tumor cells. Overexpression of Ca²⁺-activated Cl- channel anoctamin 1 (ANO1) is shown in numerous cancer types and correlates with poor prognosis. However, the mechanisms involved in ANO1-mediated malignant cellular transformation and the role of ANO1 in tumor immunity remain unknown. In this review, we discuss recent studies to determine the role of ANO1 in tumorigenesis and provide novel insights into the role of ANO1 in the context of tumor immunity. Furthermore, we analyze the roles and potential mechanisms of ANO1 in different types of cancers, and provide novel notions for the role of ANO1 in the tumor microenvironment and for potential use of ANO1 in clinical applications. Our review shows that ANO1 is involved in tumor immunity and microenvironment, and may, therefore, be an effective biomarker and therapeutic drug target.

6-Amino-2,4,5-trimethylpyridin-3-ol and 2-amino-4,6-dimethylpyrimidin-5-ol derivatives as selective fibroblast growth factor receptor 4 inhibitors: design, synthesis, molecular docking, and anti-hepatocellular carcinoma efficacy evaluation

A novel series of aminotrimethylpyridinol and aminodimethylpyrimidinol derivatives were designed and synthesised for FGFR4 inhibitors. Structure-activity relationship on the FGFR4 inhibitory activity of the new compounds was clearly elucidated by an intensive molecular docking study. Anti-cancer activity of the compounds was evaluated using hepatocellular carcinoma (HCC) cell lines and a chick chorioallantoic membrane (CAM) tumour model. Compound 6O showed FGFR4 inhibitory activity over FGFR1 - 3. Compared to the positive control BLU9931, compound 6O exhibited at least 8 times higher FGFR4 selectivity. Strong anti-proliferative activity of compound 6O was observed against Hep3B, an HCC cell line which was a much more sensitive cell line to BLU9931. In vivo anti-tumour activity of compound 6O against Hep3B-xenografted CAM tumour model was almost similar to BLU9931. Overall, compound 6O, a novel derivative of aminodimethylpyrimidinol, was a selective FGFR4 kinase inhibitor blocking HCC tumour growth.

Zafirlukast inhibits the growth of lung adenocarcinoma via inhibiting TMEM16A channel activity

Lung cancer has the highest mortality among cancers worldwide due to its high incidence and lack of the effective cures. We have previously demonstrated that the membrane ion channel TMEM16A is a potential drug target for the treatment of lung adenocarcinoma and have identified a pocket of inhibitor binding that provides the basis for screening promising new inhibitors. However, conventional drug discovery strategies are lengthy and costly, and the unpredictable side effects lead to a high failure rate in drug development. Therefore, finding new therapeutic directions for already marketed drugs may be a feasible strategy to obtain safe and effective therapeutic drugs. Here, we screened a library of over 1400 Food and Drug Administration-approved drugs through virtual screening and activity testing. We identified a drug candidate, Zafirlukast (ZAF), clinically approved for the treatment of asthma, that could inhibit the TMEM16A channel in a concentration-dependent manner. Molecular dynamics simulations and site-directed mutagenesis experiments showed that ZAF can bind to S387/N533/R535 in the nonselective inhibitor binding pocket, thereby blocking the channel pore. Furthermore, we demonstrate ZAF can target TMEM16A channel to inhibit the proliferation and migration of lung adenocarcinoma LA795 cells. In vivo experiments showed that ZAF can significantly inhibit lung adenocarcinoma tumor growth in mice. Taken together, we identified ZAF as a novel TMEM16A channel inhibitor with excellent anticancer activity, and as such, it represents a promising candidate for future preclinical and clinical studies.

Pathophysiological role of ion channels and transporters in HER2-positive breast cancer

The incidence of breast cancer (BC) has been increasing each year, and BC is now the most common malignant tumor in women. Among the numerous BC subtypes, HER2-positive BC can be treated with a variety of strategies based on targeting HER2. Although there has been great progress in the treatment of HER2-positive BC, recurrence, metastasis and drug resistance remain considerable challenges. The dysfunction of ion channels and transporters can affect the development and progression of HER2-positive BC, so these entities are expected to be new therapeutic targets. This review summarizes various ion channels and transporters associated with HER2-positive BC and suggests potential targets for the development of new and effective therapies.

Liprins in oncogenic signaling and cancer cell adhesion

Liprins are a multifunctional family of scaffold proteins, identified by their involvement in several important neuronal functions related to signaling and organization of synaptic structures. More recently, the knowledge on the liprin family has expanded from neuronal functions to processes relevant to cancer progression, including cell adhesion, cell motility, cancer cell invasion, and signaling. These proteins consist of regions, which by prediction are intrinsically disordered, and may be involved in the assembly of supramolecular structures relevant for their functions. This review summarizes the current understanding of the functions of liprins in different cellular processes, with special emphasis on liprins in tumor progression. The available data indicate that liprins may be potential biomarkers for cancer progression and may have therapeutic importance.

Copy number alterations identify a smoking-associated expression signature predictive of poor outcome in head and neck squamous cell carcinoma

Cigarette smoking is a risk factor for the development of head and neck squamous cell carcinoma (HNSCC), partially due to tobacco-induced large-scale chromosomal copy-number alterations (CNAs). Identifying CNAs caused by smoking is essential in determining how gene expression from such regions impact tumor progression and patient outcome. We utilized The Cancer Genome Atlas (TCGA) whole genome sequencing data for HNSCC to directly identify amplified or deleted genes correlating with smoking pack-year based on linear modeling. Internal cross-validation identified 35 CNAs that significantly correlated with patient smoking, independent of human papillomavirus (HPV) status. The most abundant CNAs were chromosome 11q13.3-q14.4 amplification and 9p23.1/9p24.1 deletion. Evaluation of patient amplicons reveals four different patterns of 11q13 gene amplification in HNSCC resulting from breakage-fusion-bridge (BFB) events. . Predictive modeling identified 16 genes from these regions that denote poorer overall and disease-free survival with increased pack-year use, constituting a smoking-associated expression signature (SAES). Patients with altered expression of signature genes have increased risk of death and enhanced cervical lymph node involvement. The identified SAES can be utilized as a novel predictor of increased disease aggressiveness and poor outcome in smoking-associated HNSCC.

A novel patient stratification strategy to enhance the therapeutic efficacy of dasatinib in glioblastoma

BACKGROUND

Glioblastoma is the most common primary malignancy of the central nervous system with dismal prognosis. Genomic signatures classify isocitrate dehydrogenase 1 (IDH)-wildtype glioblastoma into three subtypes: proneural, mesenchymal and classical. Dasatinib, an inhibitor of proto-oncogene kinase Src (SRC), is one of many therapeutics which, despite promising preclinical results, has failed to improve overall survival in glioblastoma patients in clinical trials. We examined whether glioblastoma subtypes differ in their response to dasatinib and could hence be evaluated for patient enrichment strategies in clinical trials.

METHODS

We carried out in silico analyses on glioblastoma gene expression (TCGA) and single-cell RNA-Seq data. In addition, in vitro experiments using glioblastoma stem-like cells (GSCs) derived from primary patient tumors were performed, with complementary gene expression profiling and immunohistochemistry analysis of tumor samples.

RESULTS

Patients with the mesenchymal subtype of glioblastoma showed higher SRC pathway activation based on gene expression profiling. Accordingly, mesenchymal GSCs were more sensitive to SRC inhibition by dasatinib compared to proneural and classical GSCs. Notably, SRC phosphorylation status did not predict response to dasatinib treatment. Furthermore, serpin peptidase inhibitor clade H member 1 (SERPINH1), a collagen related heat-shock protein associated with cancer progression, was shown to correlate with dasatinib response and with the mesenchymal subtype.

CONCLUSION

This work highlights further molecular-based patient selection strategies in clinical trials and suggests the mesenchymal subtype as well as SERPINH1 to be associated with response to dasatinib. Our findings indicate that stratification based on gene expression subtyping should be considered in future dasatinib trials.

Diethylstilbestrol, a Novel ANO1 Inhibitor, Exerts an Anticancer Effect on Non-Small Cell Lung Cancer via Inhibition of ANO1

Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer-related mortality; thus, therapeutic targets continue to be developed. Anoctamin1 (ANO1), a novel drug target considered for the treatment of NSCLC, is a Ca²⁺-activated chloride channel (CaCC) overexpressed in various carcinomas. It plays an important role in the development of cancer; however, the role of ANO1 in NSCLC is unclear. In this study, diethylstilbestrol (DES) was identified as a selective ANO1 inhibitor using high-throughput screening. We found that DES inhibited yellow fluorescent protein (YFP) fluorescence reduction caused by ANO1 activation but did not inhibit cystic fibrosis transmembrane conductance regulator channel activity or P2Y activation-related cytosolic Ca²⁺ levels. Additionally, electrophysiological analyses showed that DES significantly reduced ANO1 channel activity, but it more potently reduced ANO1 protein levels. DES also inhibited the viability and migration of PC9 cells via the reduction in ANO1, phospho-ERK1/2, and phospho-EGFR levels. Moreover, DES induced apoptosis by increasing caspase-3 activity and PARP-1 cleavage in PC9 cells, but it did not affect the viability of hepatocytes. These results suggest that ANO1 is a crucial target in the treatment of NSCLC, and DES may be developed as a potential anti-NSCLC therapeutic agent.

ORAOV1-B Promotes OSCC Metastasis via the NF-κB-TNFα Loop

Metastasis, a powerful prognostic indicator of oral squamous cell carcinoma (OSCC), is chiefly responsible for poor cancer outcomes. Despite an increasing number of studies examining the mechanisms underlying poor outcomes, the development of potent strategies is hindered by insufficient characterization of the crucial regulators. Long noncoding RNAs (lncRNAs) have recently been gaining interest as significant modulators of OSCC metastasis; however, the detailed mechanisms underlying lncRNA-mediated OSCC metastasis remain relatively uncharacterized. Here, we identified a novel alternative splice variant of oral cancer overexpressed 1 (ORAOV1), named as ORAOV1-B, which was subsequently validated as an lncRNA and correlated with OSCC lymph node metastasis; significantly increased invasion and migration were observed in ORAOV1-B-overexpressing OSCC cells. RNA pulldown and mass spectrometry identified Hsp90 as a direct target of ORAOV1-B, and cDNA microarrays suggested TNFα as a potential downstream target of ORAOV1-B. ORAOV1-B was shown to directly bind to and stabilize Hsp90, which maintains the function of client proteins, receptor-interaction protein, and IκB kinase beta, thus activating the NF-κB pathway and inducing TNFα. Additionally, TNFα reciprocally enhanced p-NF-κB-p65 and the downstream epithelial-mesenchymal transition. ORAOV1-B effects were reversed by a TNFα inhibitor, demonstrating that TNFα is essential for ORAOV1-B-regulated metastatic ability. Consistent epithelial-mesenchymal transition in the ORAOV1-B group was demonstrated via an orthotopic model. In the metastatic model, ORAOV1-B significantly contributed to OSCC-related lung metastasis. In summary, the novel splice variant ORAOV1-B is an lncRNA, which significantly potentiates OSCC invasion and metastasis by binding to Hsp90 and activating the NF-κB-TNFα loop. These findings demonstrate the versatile role of ORAOV1 family members and the significance of genes located within 11q13 in promoting OSCC. ORAOV1-B might serve as an attractive OSCC metastasis intervention target.

ANO1 regulates the maintenance of stemness in glioblastoma stem cells by stabilizing EGFRvIII

Glioblastoma multiforme (GBM) or glioblastoma is the most deadly malignant brain tumor in adults. GBM is difficult to treat mainly due to the presence of glioblastoma stem cells (GSCs). Epidermal growth factor receptor variant III (EGFRvIII) has been linked to stemness and malignancy of GSCs; however, the regulatory mechanism of EGFRvIII is largely unknown. Here, we demonstrated that Anoctamin-1 (ANO1), a Ca²⁺-activated Cl^- channel, interacts with EGFRvIII, increases its protein stability, and supports the maintenance of stemness and tumor progression in GSCs. Specifically, shRNA-mediated knockdown and pharmacological inhibition of ANO1 suppressed the self-renewal, invasion activities, and expression of EGFRvIII and related stem cell factors, including NOTCH1, nestin, and SOX2 in GSCs. Conversely, ANO1 overexpression enhanced the above phenomena. Mechanistically, ANO1 protected EGFRvIII from proteasomal degradation by directly binding to it. ANO1 knockdown significantly increased survival in mice and strongly suppressed local invasion of GSCs in an in vivo intracranial mouse model. Collectively, these results suggest that ANO1 plays a crucial role in the maintenance of stemness and invasiveness of GSCs by regulating the expression of EGFRvIII and related signaling molecules, and can be considered a promising therapeutic target for GBM treatment.

Copy number variations in primary tumor, serum and lymph node metastasis of bladder cancer patients treated with radical cystectomy

The aim of the present study was to analyze copy number variations (CNV) of multiple oncogenes and tumor suppressor genes in genomic DNA from primary tumor tissue, lymph node metastasis and cell-free DNA (cfDNA) from serum of 72 urothelial carcinoma of bladder (UCB) patients treated with radical cystectomy (RC), using multiplex ligation-dependent probe amplification (MLPA). We hypothesized that primary tumor and lymph node metastasis show similar CNV profiles, and CNV are more present in lymph node metastasis compared to primary tumor tissue. Samples from 43 (59.7%) patients could be analyzed. In total, 35 (83%), 26 (68%) and 8 (42%) patients had CNV in primary tumor, serum and lymph node metastasis, respectively. MYC, CCND1, ERBB2 and CCNE1 displayed the most frequent amplifications. In particular, CNV in ERBB2 was associated with aggressive tumor characteristics. CNV in both ERBB2 and TOP2A were risk factors for disease recurrence. The current findings show that CNV are present in various oncogenes and tumor suppressor genes in genomic DNA from primary tumor, lymph node metastasis and cfDNA from serum. CNV were more present in genomic DNA from primary tumor tissue compared to cfDNA from serum and genomic DNA from lymph node metastasis. Patients with CNV in ERBB2 and TOP2A are at increased risk for disease recurrence following RC. Further studies are necessary to validate, whether these genes may represent promising candidates for targeted-therapy.

Validation of ORAOV1 as a new treatment target in hepatocellular carcinoma

PURPOSE

Chromosome 11q13.2, which contains genes cyclin D1 (CCND1), fibroblast growth factor 19 (FGF19), and Oral Cancer Overexpressed 1 (ORAOV1), is the most highly amplified peak in hepatocellular carcinoma (HCC). CCND1 and FGF19 have been already suggested as therapeutic targets of HCC, but the role of ORAOV1 in carcinogenesis of HCCs has not been reported.

METHODS

This retrospective study investigated ORAOV1 expression using immunohistochemistry performed on tissue microarray blocks obtained from 259 HCC patients with curative resection, between 2000 and 2006. We assessed the prognostic significance of ORAOV1 expression by Kaplan-Meier method with log-rank test and Cox proportional hazards model. Also, we performed invasion, migration, apoptosis, and cell cycle assays in HCC cell lines, and evaluated the tumorigenicity of HCC xenografts in nude mice, after knockdown of ORAOV1.

RESULTS

High expression of ORAOV1 protein was observed in 80% of HCC tissues. The ORAOV1 high expression group showed shorter recurrence free survival (RFS) (p < 0.001) and shorter disease-specific survival (DSS) than the low expression group. It was an independent prognostic factor for predicting early recurrence [Odds ratio 2.74 (95% confidence interval (CI) 1.27-5.93), p = 0.01] as well as short RFS [hazard ratio 2.23 (95% CI 1.40-3.54), p = 0.001] and DSS [hazard ratio 2.30 (95% CI 1.27-4.17), p = 0.006]. Knockdown of ORAOV1 induced significant decreases in migration, invasion, and tumorigenicity of HCC cells in in-vitro model, and inhibited the growth of HCC xenografts in nude mice.

CONCLUSION

We demonstrated unfavorable prognostic effect of ORAOV1 expression with supporting experimental data in HCC. ORAOV1 may be used as a biomarker for predicting HCC prognosis and is a potential candidate for targeted therapy.

Polyunsaturated fatty acid biosynthesis pathway and genetics. implications for interindividual variability in prothrombotic, inflammatory conditions such as COVID-19✰,✰✰,★,★★

COVID-19 symptoms vary from silence to rapid death, the latter mediated by both a cytokine storm and a thrombotic storm. SARS-CoV (2003) induces Cox-2, catalyzing the synthesis, from highly unsaturated fatty acids (HUFA), of eicosanoids and docosanoids that mediate both inflammation and thrombosis. HUFA balance between arachidonic acid (AA) and other HUFA is a likely determinant of net signaling to induce a healthy or runaway physiological response. AA levels are determined by a non-protein coding regulatory polymorphisms that mostly affect the expression of FADS1, located in the FADS gene cluster on chromosome 11. Major and minor haplotypes in Europeans, and a specific functional insertion-deletion (Indel), rs66698963, consistently show major differences in circulating AA (>50%) and in the balance between AA and other HUFA (47-84%) in free living humans; the indel is evolutionarily selective, probably based on diet. The pattern of fatty acid responses is fully consistent with specific genetic modulation of desaturation at the FADS1-mediated 20:3→20:4 step. Well established principles of net tissue HUFA levels indicate that the high linoleic acid and low alpha-linoleic acid in populations drive the net balance of HUFA for any individual. We predict that fast desaturators (insertion allele at rs66698963; major haplotype in Europeans) are predisposed to higher risk and pathological responses to SARS-CoV-2 could be reduced with high dose omega-3 HUFA.

FGFR4: A promising therapeutic target for breast cancer and other solid tumors

The fibroblast growth factor receptor (FGFR) signaling pathway has long been known to cancer researchers because of its role in cell survival, proliferation, migration, and angiogenesis. Dysregulation of FGFR signaling is frequently reported in cancer studies, but most of these studies focus on FGFR1-3. However, there is growing evidence implicating an important and unique role of FGFR4 in oncogenesis, tumor progression, and resistance to anti-tumor therapy in multiple types of cancer. Importantly, there are several novel FGFR4-specific inhibitors in clinical trials, making FGFR4 an attractive target for further research. In this review, we focus on assessing the role of FGFR4 in cancer, with an emphasis on breast cancer. First, the structure, physiological functions and downstream signaling pathways of FGFR4 are introduced. Next, different mechanisms reported to cause aberrant FGFR4 activation and their functions in cancer are discussed, including FGFR4 overexpression, FGF ligand overexpression, FGFR4 somatic hotspot mutations, and the FGFR4 G388R single nucleotide polymorphism. Finally, ongoing and recently completed clinical trials targeting FGFRs in cancer are reviewed, highlighting the therapeutic potential of FGFR4 inhibition for the treatment of breast cancer.

Hsp47 promotes cancer metastasis by enhancing collagen-dependent cancer cell-platelet interaction

Increased expression of extracellular matrix (ECM) proteins in circulating tumor cells (CTCs) suggests potential function of cancer cell-produced ECM in initiation of cancer cell colonization. Here, we showed that collagen and heat shock protein 47 (Hsp47), a chaperone facilitating collagen secretion and deposition, were highly expressed during the epithelial-mesenchymal transition (EMT) and in CTCs. Hsp47 expression induced mesenchymal phenotypes in mammary epithelial cells (MECs), enhanced platelet recruitment, and promoted lung retention and colonization of cancer cells. Platelet depletion in vivo abolished Hsp47-induced cancer cell retention in the lung, suggesting that Hsp47 promotes cancer cell colonization by enhancing cancer cell-platelet interaction. Using rescue experiments and functional blocking antibodies, we identified type I collagen as the key mediator of Hsp47-induced cancer cell-platelet interaction. We also found that Hsp47-dependent collagen deposition and platelet recruitment facilitated cancer cell clustering and extravasation in vitro. By analyzing DNA/RNA sequencing data generated from human breast cancer tissues, we showed that gene amplification and increased expression of Hsp47 were associated with cancer metastasis. These results suggest that targeting the Hsp47/collagen axis is a promising strategy to block cancer cell-platelet interaction and cancer colonization in secondary organs.

Identification of anoctamin 1 (ANO1) as a key driver of esophageal epithelial proliferation in eosinophilic esophagitis

BACKGROUND

The pathology of eosinophilic esophagitis (EoE) is characterized by eosinophil-rich inflammation, basal zone hyperplasia (BZH), and dilated intercellular spaces, and the underlying processes that drive the pathologic manifestations of the disease remain largely unexplored.

OBJECTIVE

We sought to investigate the involvement of the calcium-activated chloride channel anoctamin 1 (ANO1) in esophageal proliferation and the histopathologic features of EoE.

METHODS

We examined mRNA and protein expression of ANO1 in esophageal biopsy samples from patients with EoE and in mice with EoE. We performed molecular and cellular analyses and ion transport assays on an in vitro esophageal epithelial 3-dimensional model system (EPC2-ALI) and murine models of EoE to define the relationship between expression and function of ANO1 and esophageal epithelial proliferation in patients with EoE.

RESULTS

We observed increased ANO1 expression in esophageal biopsy samples from patients with EoE and in mice with EoE. ANO1 was expressed within the esophageal basal zone, and expression correlated positively with disease severity (eosinophils/high-power field) and BZH. Using an in vitro esophageal epithelial 3-dimensional model system revealed that ANO1 undergoes chromatin modification and rapid upregulation of expression after IL-13 stimulation, that ANO1 is the primary apical IL-13-induced Cl- transport mechanism within the esophageal epithelium, and that loss of ANO1-dependent Cl- transport abrogated esophageal epithelial proliferation. Mechanistically, ANO1-dependent regulation of basal cell proliferation was associated with modulation of TP63 expression and phosphorylated cyclin-dependent kinase 2 levels.

CONCLUSIONS

These data identify a functional role for ANO1 in esophageal cell proliferation and BZH in patients with EoE and provide a rationale for pharmacologic intervention of ANO1 function in patients with EoE.

Down-regulation of miR-9 promotes epithelial mesenchymal transition via regulating anoctamin-1 (ANO1) in CRC cells

MicroRNA-9 (miR-9) has been reported to play a suppressive or promoting role according to cancer type. In this study, we investigated the effects of anoctamin-1 (ANO1) and miR-9 on colorectal cancer (CRC) cell proliferation, migration, and invasion and determined the underlying molecular mechanisms. Thirty-two paired CRC tissues and adjacent normal tissues were analyzed for ANO1 expression using quantitative real-time PCR (qRT-PCR). HCT116 cells were transiently transfected with miR-9 mimic, miR-9 inhibitor, or si-ANO1. Cell proliferation was determined by MTT, and flow cytometric analysis, while cell migration and invasion were assayed by trans-well migration and invasion assay in HCT116 cells. ANO1 was validated as a target of miR-9 using luciferase reporter assay and bioinformatics algorithms. We found that ANO1 expression was up-regulated in CRC tissues compared with adjacent normal tissues. ANO1 expression was associated with advanced tumor stage and lymph node metastasis, and there was an inverse relationship between miR-9 and ANO1 mRNA expression in CRC specimens, but no significant difference was found between miR-9 and ANO1 expression. ANO1 is a direct target of miR-9, and overexpression of miR-9 suppressed both mRNA and protein expression of ANO1 and inhibited cell proliferation, migration, and invasion of HCT116 cells. We also showed that overexpression of miR-9 suppressed expression of p-AKT, cyclin D1, and p-ERK in HCT116 cells. We conclude that miR-9 inhibits CRC cell proliferation, migration, and invasion by directly targeting ANO1, and miR-9/ANO1 could be a potential therapeutic target for CRC.

Fibroblast Growth Factor Receptor 4 Targeting in Cancer: New Insights into Mechanisms and Therapeutic Strategies

Fibroblast growth factor receptor 4 (FGFR4), a tyrosine kinase receptor for FGFs, is involved in diverse cellular processes, including the regulation of cell proliferation, differentiation, migration, metabolism, and bile acid biosynthesis. High activation of FGFR4 is strongly associated with the amplification of its specific ligand FGF19 in many types of solid tumors and hematologic malignancies, where it acts as an oncogene driving the cancer development and progression. Currently, the development and therapeutic evaluation of FGFR4-specific inhibitors, such as BLU9931 and H3B-6527, in animal models and cancer patients, are paving the way to suppress hyperactive FGFR4 signaling in cancer. This comprehensive review not only covers the recent discoveries in understanding FGFR4 regulation and function in cancer, but also reveals the therapeutic implications and applications regarding emerging anti-FGFR4 agents. Our aim is to pinpoint the potential of FGFR4 as a therapeutic target and identify new avenues for advancing future research in the field.

Oncogenic long noncoding RNA MALAT1 and HCV-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality worldwide. The oncogenic function of the long non-coding RNA; metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in HCC remains unclear. We aimed to evaluate MALAT1 serum expression profile in HCC and explore its relation to the clinicopathological features. Quantitative Real Time-Polymerase Chain Reaction was applied in 70 cohorts (30 HCC, 20 HCV, 20 controls). Further meta-analysis of clinical studies and in vitro validated experiments was employed. Serum MALAT1 showed area under the curve of 0.79 and 0.70 to distinguish patients with cancer from normal and cirrhotic individuals at fold change of 1.0 and 1.26, respectively. Expression level was significantly higher in males (P <0.001) and patients with massive ascites (P = 0.005). Correlation analysis showed positive correlation of MALAT1 with total bilirubin (r = 0.456, P <0.001) and AST (r = 0.280, P = 0.019), and negative correlation with the hemoglobin level (r = 0.312, P = 0.009). Meta-analysis showed that the over-expressed MALAT1 was linked to tumor number [Cohen's d = 0.450, 95% CI (0.21 to 0.68)], clinical stage [Cohen's d = 0.048, 95% CI (-0.83 to 0.74)], and AFP level [Cohen's d = 0.354, 95% CI (0.1 to 0.57)]. In silico data analysis and systematic review confirmed MALAT1 oncogenic function in cancer development and progression. In conclusion, circulatory MALAT1 might represent a putative non-invasive prognostic biomarker indicating worse liver failure score in HCV-related HCC patients with traditional markers. Large-scale verification is warranted in future studies.

Inhibition of calcium-activated chloride channel ANO1 suppresses proliferation and induces apoptosis of epithelium originated cancer cells

ANO1, a calcium-activated chloride channel, has been reported to be amplified or overexpressed in tissues of several cancers. However, reports on its roles in tumor progression obtained from cancer cell lines are inconsistent, suggesting that the role of ANO1 in tumorigenesis is likely dependent on either its expression level or cell-type expressing ANO1. To investigate the biological roles of ANO1 in different tumor cells, we, in this study, selected several cancer cell lines and a normal HaCaT cell line with high expression levels of ANO1, and examined the function of ANO1 in these cells using approaches of lentiviral knockdown and pharmacological inhibition. We found that ANO1 knockdown significantly inhibited cell proliferation and induced cell apoptosis in either tumor cell lines or normal HaCaT cell line. Moreover, silencing ANO1 arrested cancer cells at G1 phase of cell cycle. Treatment with ANO1 inhibitor CaCC_inh-A01 reduced cell viability in a dose-dependent manner. Furthermore, both ANO1 inhibitors CaCC_inh-A01 and T16A_inh-A01 significantly suppressed cell migration. Our findings show that ANO1 overexpression promotes cancer cell proliferation and migration; and genetic or pharmacological inhibition of ANO1 induces apoptosis and cell cycle arrest at G1 phase in different types of epithelium-originated cancer cells.

DNA methylation regulates TMEM16A/ANO1 expression through multiple CpG islands in head and neck squamous cell carcinoma

ANO1 is a calcium-activated chloride channel that is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC) and other cancers. While ANO1 expression negatively correlates with survival in several cancers, its epigenetic regulation is poorly understood. We analyzed HNSCC samples from TCGA and a separate dataset of HPV+ oropharyngeal squamous cell carcinoma (OPSCC) samples to identify differentially methylated regions. E6 and E7 transfected normal oral keratinocytes (NOK) were used to induce hypermethylation of the ANO1 promoter. We found three CpG islands that correlated with ANO1 expression, including two positively correlated with expression. Using two HNSCC datasets with differential expression of ANO1, we showed hypermethylation of positively correlated CpG islands potentiates ANO1 expression. E7 but not E6 transfection of NOK cells led to hypermethylation of a positively correlated CpG island without a change in ANO1 expression. ANO1 promoter methylation was also correlated with patient survival. Our results are the first to show the contribution of positively correlated CpG’s for regulating gene expression in HNSCC. Hypermethylation of the ANO1 promoter was strongly correlated with but not sufficient to increase ANO1 expression, suggesting methylation of positively correlated CpG’s likely serves as an adjunct to other mechanisms of ANO1 activation.

Cell-specific mechanisms of TMEM16A Ca2+-activated chloride channel in cancer

TMEM16A (known as anoctamin 1) Ca2+-activated chloride channel is overexpressed in many tumors. TMEM16A overexpression can be caused by gene amplification in many tumors harboring 11q13 amplification. TMEM16A expression is also controlled in many cancer cells via transcriptional regulation, epigenetic regulation and microRNAs. In addition, TMEM16A activates different signaling pathways in different cancers, e.g. the EGFR and CAMKII signaling in breast cancer, the p38 and ERK1/2 signaling in hepatoma, the Ras-Raf-MEK-ERK1/2 signaling in head and neck squamous cell carcinoma and bladder cancer, and the NFκB signaling in glioma. Furthermore, TMEM16A overexpression has been reported to promote, inhibit, or produce no effects on cell proliferation and migration in different cancer cells. Since TMEM16A exerts different roles in different cancer cells via activation of distinct signaling pathways, we try to develop the idea that TMEM16A regulates cancer cell proliferation and migration in a cell-dependent mechanism. The cell-specific role of TMEM16A may depend on the cellular environment that is predetermined by TMEM16A overexpression mechanisms specific for a particular cancer type. TMEM16A may exert its cell-specific role via its associated protein networks, phosphorylation by different kinases, and involvement of different signaling pathways. In addition, we discuss the role of TMEM16A channel activity in cancer, and its clinical use as a prognostic and predictive marker in different cancers. This review highlights the cell-type specific mechanisms of TMEM16A in cancer, and envisions the promising use of TMEM16A inhibitors as a potential treatment for TMEM16A-overexpressing cancers.

Expression of ORAOV1, CD133 and WWOX correlate with metastasis and prognosis in gastric adenocarcinoma

BACKGROUND

Oral cancer overexpressed 1 (ORAOV1) which is a novel candidate oncogene is a useful biomarker of metastasis and prognosis in various cancers. CD133 which is a biomarker of cancer stem cells is overexpressed in many cancers and promotes cancer cells growth and metastasis. WW domain-containing oxidoreductase (WWOX) which is a suppressor gene of tumor can inhibit proliferation and promote apoptosis in various cancers. However, associations among ORAOV1, CD133, and WWOX and their clinicopathological significance in gastric adenocarcionma (GAC) are unclear. In this study, we analyzed associations among ORAOV1, CD133, and WWOX in GAC, and their respective associations with clinicopathological characteristics and survival in GAC.

METHOD

Positive expression of ORAOV1, CD133, and WWOX in 236 whole GAC tissue samples were detected by immunohistochemistry staining. Patients' clinical data were also collected.

RESULTS

Levels of ORAOV1 and CD133 were significantly higher, and levels of WWOX significantly lower, in GAC tissues than in normal gastric tissues. Levels of ORAOV1 and CD133 were positively associated with tumor grade, invasion of depth, lymph node metastasis (LNM), and tumor-node metastasis (TNM) stages, and inversely with patients overall survival time; levels of WWOX was negatively correlated with tumor grade, invasion of depth, LNM, and TNM stages, and the WWOX-positive subgroup had significantly longer overall survival time than did the WWOX-negative subgroup. In multivariate analysis, high expression of ORAOV1 and CD133, invasion of depth, and TNM stages, and low expression of WWOX were potential to be independent prognostic factors for overall survival time in patients with GAC.

CONCLUSIONS

The expression of ORAOV1, CD133, and WWOX represent promising biomarkers for metastasis and prognosis, and potential therapeutic targets for GAC.

VP2 of Infectious Bursal Disease Virus Induces Apoptosis via Triggering Oral Cancer Overexpressed 1 (ORAOV1) Protein Degradation

Infectious bursal disease (IBD) is an acute, highly contagious and immunosuppressive avian disease caused by IBD virus (IBDV). Cell apoptosis triggered by IBDV contributes to the dysfunction of immune system in host. VP2 of IBDV is known to induce cell death but the underlying mechanism remains unclear. Here we demonstrate that VP2 interacts with the oral cancer overexpressed 1 (ORAOV1), a potential oncoprotein. Infection by IBDV or ectopic expression of VP2 causes a reduction of cellular ORAOV1 and induction of apoptosis, so does knockdown of ORAOV1. In contrast, over-expression of ORAOV1 leads to the inhibition of VP2- or IBDV-induced apoptosis, accompanied with the decreased viral release (p < 0.05). Thus, VP2-induced apoptosis during IBDV infection is mediated by interacting with and reducing ORAOV1, a protein that appears to act as an antiapoptotic molecule and restricts viral release early during IBDV infection.

TMEM16A/ANO1 suppression improves response to antibody-mediated targeted therapy of EGFR and HER2/ERBB2

TMEM16A, a Ca²⁺ -activated Cl^- channel, contributes to tumor growth in breast cancer and head and neck squamous cell carcinoma (HNSCC). Here, we investigated whether TMEM16A influences the response to EGFR/HER family-targeting biological therapies. Inhibition of TMEM16A Cl^- channel activity in breast cancer cells with HER2 amplification induced a loss of viability. Cells resistant to trastuzumab, a monoclonal antibody targeting HER2, showed an increase in TMEM16A expression and heightened sensitivity to Cl^- channel inhibition. Treatment of HNSCC cells with cetuximab, a monoclonal antibody targeting EGFR, and simultaneous TMEM16A suppression led to a pronounced loss of viability. Biochemical analyses of cells subjected to TMEM16A inhibitors or expressing chloride-deficient forms of TMEM16A provide further evidence that TMEM16A channel function may play a role in regulating EGFR/HER2 signaling. These data demonstrate that TMEM16A regulates EGFR and HER2 in growth and survival pathways. Furthermore, in the absence of TMEM16A cotargeting, tumor cells may acquire resistance to EGFR/HER inhibitors. Finally, targeting TMEM16A improves response to biological therapies targeting EGFR/HER family members.

Shikonin Inhibits Intestinal Calcium-Activated Chloride Channels and Prevents Rotaviral Diarrhea

Secretory diarrhea remains a global health burden and causes major mortality in children. There have been some focuses on antidiarrheal therapies that may reduce fluid losses and intestinal motility in diarrheal diseases. In the present study, we identified shikonin as an inhibitor of TMEM16A chloride channel activity using cell-based fluorescent-quenching assay. The IC50 value of shikonin was 6.5 μM. Short-circuit current measurements demonstrated that shikonin inhibited Eact-induced Cl(-) current in a dose-dependent manner, with IC50 value of 1.5 μM. Short-circuit current measurement showed that shikonin exhibited inhibitory effect against CCh-induced Cl(-) currents in mouse colonic epithelia but did not affect cytoplasmic Ca(2+) concentration as well as the other major enterocyte chloride channel conductance regulator. Characterization study found that shikonin inhibited basolateral K(+) channel activity without affecting Na(+)/K(+)-ATPase activities. In vivo studies revealed that shikonin significantly delayed intestinal motility in mice and reduced stool water content in a neonatal mice model of rotaviral diarrhea without affecting the viral infection process in vivo. Taken together, the results suggested that shikonin inhibited enterocyte calcium-activated chloride channels, the inhibitory effect was partially through inhbition of basolateral K(+) channel activity, and shikonin could be a lead compound in the treatment of rotaviral secretory diarrhea.

Jagged1 DNA Copy Number Variation Is Associated with Poor Outcome in Liver Cancer

Notch signaling abnormalities are reported to be involved in the acceleration of malignancy in solid tumors and stem cell formation or regeneration in various organs. We analyzed specific genes for DNA copy number variations in liver cancer cells and investigated whether these factors relate to clinical outcome. Chromosome 20p, which includes the ligand for Notch pathways, Jagged1, was found to be amplified in several types of hepatoma cells, and its mRNA was up-regulated according to α-fetoprotein gene expression levels. Notch inhibition using Jagged1 shRNA and γ-secretase inhibitors produced significant suppression of cell growth in α-fetoprotein-producing cells with suppression of downstream genes. Using in vivo hepatoma models, the administration of γ-secretase inhibitors resulted in reduced tumor sizes and effective Notch inhibition with widespread apoptosis and necrosis of viable tumor cells. The γ-secretase inhibitors suppressed cell growth of the epithelial cell adhesion molecule-positive fraction in hepatoma cells, indicating that Notch inhibitors could suppress the stem cell features of liver cancer cells. Even in clinical liver cancer samples, the expression of α-fetoprotein and Jagged1 showed significant correlation, and amplification of the copy number of Jagged1 was associated with Jagged1 mRNA expression and poor survival after liver cancer surgical resection. In conclusion, amplification of Jagged1 contributed to mRNA expression that activates the Jagged1-Notch signaling pathway in liver cancer and led to poor outcome.

Suppression of 14-3-3γ-mediated surface expression of ANO1 inhibits cancer progression of glioblastoma cells

Anoctamin-1 (ANO1) acts as a Ca²⁺-activated Cl⁻ channel in various normal tissues, and its expression is increased in several different types of cancer. Therefore, understanding the regulation of ANO1 surface expression is important for determining its physiological and pathophysiological functions. However, the trafficking mechanism of ANO1 remains elusive. Here, we report that segment a (N-terminal 116 amino acids) of ANO1 is crucial for its surface expression, and we identified 14-3-3γ as a binding partner for anterograde trafficking using yeast two-hybrid screening. The surface expression of ANO1 was enhanced by 14-3-3γ, and the Thr9 residue of ANO1 was critical for its interaction with 14-3-3γ. Gene silencing of 14-3-3γ and/or ANO1 demonstrated that suppression of ANO1 surface expression inhibited migration and invasion of glioblastoma cells. These findings provide novel therapeutic implications for glioblastomas, which are associated with poor prognosis.

RNAi-mediated downregulation of oral cancer overexpressed 1 (ORAOV1) inhibits vascular endothelial cell proliferation, migration, invasion, and tube formation

BACKGROUND

Oral squamous cell carcinoma (OSCC) is one of the top ten tumors threatening human health. Oral cancer overexpressed 1 (ORAOV1) identified within chromosomal region 11q13, one of the most frequently amplified regions in OSCC, has been suggested as a novel candidate oncogene in OSCC, regulating cell cycle, apoptosis, and angiogenesis. In this study, we investigated the role of ORAOV1 in OSCC-induced angiogenesis in vitro.

METHODS

EA.hy926 human endothelial cells were co-cultured with OSCC cells (HSC-3 and SCC-25) transfected with ORAOV1-specific shRNA to downregulate ORAOV1 expression, and analyzed for proliferation, migration, invasion, and tube formation by specific assays.

RESULTS

EA.hy926 endothelial cells co-cultured with ORAOV1-deficient OSCC cells exhibited significantly lower proliferation, migration, and invasion, as well as the activity in tube formation compared to that in the control cells.

CONCLUSIONS

Our results show, for the first time, that ORAOV1 expressed by OSCC cells promotes tube formation by endothelial cells, indicating its involvement in OSCC angiogenesis. Considering the importance of neovascularization in tumor development and metastasis, these findings suggest that targeting ORAOV1 may be a potential therapeutic strategy against OSCC.

ANO1/TMEM16A interacts with EGFR and correlates with sensitivity to EGFR-targeting therapy in head and neck cancer

The epidermal growth factor receptor (EGFR) contributes to the pathogenesis of head&neck squamous cell carcinoma (HNSCC). However, only a subset of HNSCC patients benefit from anti-EGFR targeted therapy. By performing an unbiased proteomics screen, we found that the calcium-activated chloride channel ANO1 interacts with EGFR and facilitates EGFR-signaling in HNSCC. Using structural mutants of EGFR and ANO1 we identified the trans/juxtamembrane domain of EGFR to be critical for the interaction with ANO1. Our results show that ANO1 and EGFR form a functional complex that jointly regulates HNSCC cell proliferation. Expression of ANO1 affected EGFR stability, while EGFR-signaling elevated ANO1 protein levels, establishing a functional and regulatory link between ANO1 and EGFR. Co-inhibition of EGFR and ANO1 had an additive effect on HNSCC cell proliferation, suggesting that co-targeting of ANO1 and EGFR could enhance the clinical potential of EGFR-targeted therapy in HNSCC and might circumvent the development of resistance to single agent therapy. HNSCC cell lines with amplification and high expression of ANO1 showed enhanced sensitivity to Gefitinib, suggesting ANO1 overexpression as a predictive marker for the response to EGFR-targeting agents in HNSCC therapy. Taken together, our results introduce ANO1 as a promising target and/or biomarker for EGFR-directed therapy in HNSCC.