Expression of ANO1/DOG1 is associated with shorter survival and progression of breast carcinomas

TMEM16A ion channel: A novel target for cancer treatment

Cancer draws attention owing to the high morbidity and mortality. It is urgent to develop safe and effective cancer therapeutics. The calcium-activated chloride channel TMEM16A is widely distributed in various tissues and regulates physiological functions. TMEM16A is abnormally expressed in several cancers and associate with tumorigenesis, metastasis, and prognosis. Knockdown or inhibition of TMEM16A in cancer cells significantly inhibits cancer development. Therefore, TMEM16A is considered as a biomarker and therapeutic target for some cancers. This work reviews the cancers associated with TMEM16A. Then, the molecular mechanism of TMEM16A overexpression in cancer was analyzed, and the possible signal transduction mechanism of TMEM16A regulating cancer development was summarized. Finally, TMEM16A inhibitors with anticancer effect and their anticancer mechanism were concluded. We hope to provide new ideas for pharmacological studies on TMEM16A in cancer.

DOG1 expression in neuroendocrine neoplasms: Potential applications and diagnostic pitfalls

Neuroendocrine neoplasms represent a heterogeneous group of rare tumors, more frequently arising from gastroenteropancreatic tract and lungs. At the time of diagnosis, 20% of cases are metastatic, and 10% of cases are considered as cancer of unknown primary origin. Several immunohistochemical markers are routinely used to confirm the neuroendocrine differentiation, first among all Synaptophysin and Chromogranin-A; on the other hand, different immunohistochemical markers are used to establish primary anatomical site, as TTF1, CDX2, Islet-1 and Calcitonin, but no marker is available in order to distinguish among different sites of the digestive tract. DOG1 (discovered on GIST-1) is a gene normally expressed in interstitial cells of Cajal and, in routine practice, DOG1 immunostaining is used in diagnosis of GIST (gastrointestinal stromal tumor). DOG1 expression has been described in several neoplasms other than GIST, both in mesenchymal and epithelial neoplasms. In the present study, DOG1 immunostaining has been performed in a large cohort of neuroendocrine neoplasms, including neuroendocrine tumors and neuroendocrine carcinomas, in order to evaluate frequency, intensity and pattern of expression in different anatomical site and in different tumor grade. DOG1 expression was detected in a large percentage of neuroendocrine tumors, with statistically significant association between DOG1 expression and gastrointestinal tract neuroendocrine tumors. As a consequence, DOG1 could be included in marker panel for the identification of primary site in neuroendocrine metastases of unknown primary origin; moreover, these results recommend careful evaluation of DOG1 expression in gastrointestinal neoplasms, in particular in differential diagnosis between epithelioid GIST and neuroendocrine tumors.

High level of ANO1 promotes pancreatic cancer growth in concert with oncogenic KRAS

BACKGROUND

Anoctamin-1 (ANO1) was identified as an unfavorable prognostic marker in pancreatic cancer. However, the exact implication of ANO1 in pancreatic cancer is still poorly understood. Here we investigated the effect of ANO1 in pancreatic cancer progression under the context of oncogenic KRAS, aiming at finding a new therapeutic target.

METHODS

Knockdown and overexpression of oncogenic KRAS as well as ANO1 in PDAC cell lines were performed by lentivirus infection. Cell proliferation and migration assay, RNA seq analysis were performed in PDAC cells bearing different status of ANO1 and KRAS. In vivo mice model was used to investigate the xenograft tumor growth with different status of KRAS and ANO1.

RESULTS

Our results showed that ANO1 expression level is elevated in poorly differentiated cancer cells. Overexpression of ANO1 in PDAC cancer cells was found to promote cancer cell proliferation in vitro and in vivo, which synergized with the introduction of oncogenic KRAS. Consistently, knockdown of ANO1 expression was found to suppress cancer growth in vitro and in vivo. RNA seq analysis revealed that the observed synergistic cancer-promoting effect from ANO1 and oncogenic KRAS is likely due to concurrent activating key genes involved in lipid metabolism including HMGCS1.

CONCLUSION

The outcome from our study suggests that ANO1 plays an important role in promoting pancreatic cancer development, especially at the presence of oncogenic KRAS. Considering the prevalence of KRAS mutation in pancreatic cancer patients, suppression ANO1 may represent a potential effective therapeutic measure in pancreatic cancer treatment.

DOG1 overexpression is associated with mismatch repair deficiency and BRAF mutations but unrelated to cancer progression in colorectal cancer

INTRODUCTION

The transmembrane channel protein DOG1 (Discovered on GIST1) is normally expressed in the gastrointestinal interstitial cells of Cajal and also in gastrointestinal stroma tumors arising from these cells. However, there is also evidence for a relevant role of DOG1 expression in colorectal cancers. This study was undertaken to search for associations between DOG1 expression and colon cancer phenotype and key molecular alterations.

METHODS

A tissue microarray containing samples from more than 1,800 colorectal cancer patients was analyzed by immunohistochemistry.

RESULTS

DOG1 immunostaining was detected in 503 (30.2%) of 1,666 analyzable colorectal cancers and considered weak in 360 (21.6%), moderate in 78 (4.7%), and strong in 65 (3.9%). Strong DOG1 immunostaining was associated with advanced pT stage (p=0.0367) and nodal metastases (p=0.0145) but these associations were not retained in subgroups of 1,135 mismatch repair proficient and 86 mismatch repair deficient tumors. DOG1 positivity was significantly linked to several molecular tumor features including mismatch repair deficiency (p=0.0034), BRAF mutations (p<0.0001), nuclear p53 accumulation (p=0.0157), and PD-L1 expression (p=0.0199) but unrelated to KRAS mutations and the density of tumor infiltrating CD8 positive lymphocytes.

CONCLUSION

Elevated DOG1 expression is frequent in colorectal cancer and significantly linked to important molecular alterations. However, DOG1 overexpression is largely unrelated to histopathological parameters of cancer aggressiveness and may thus not serve as a prognostic parameter for this tumor entity.

TMEM16A as a potential treatment target for head and neck cancer

Transmembrane protein 16A (TMEM16A) forms a plasma membrane-localized Ca²⁺-activated Cl- channel. Its gene has been mapped to an area on chromosome 11q13, which is amplified in head and neck squamous cell carcinoma (HNSCC). In HNSCC, TMEM16A overexpression is associated with not only high tumor grade, metastasis, low survival, and poor prognosis, but also deterioration of clinical outcomes following platinum-based chemotherapy. Recent study revealed the interaction between TMEM16A and transforming growth factor-β (TGF-β) has an indirect crosstalk in clarifying the mechanism of TMEM16A-induced epithelial-mesenchymal transition. Moreover, human papillomavirus (HPV) infection can modulate TMEM16A expression along with epidermal growth factor receptor (EGFR), whose phosphorylation has been reported as a potential co-biomarker of HPV-positive cancers. Considering that EGFR forms a functional complex with TMEM16A and is a co-biomarker of HPV, there may be crosstalk between TMEM16A expression and HPV-induced HNSCC. EGFR activation can induce programmed death ligand 1 (PD-L1) synthesis via activation of the nuclear factor kappa B pathway and JAK/STAT3 pathway. Here, we describe an interplay among EGFR, PD-L1, and TMEM16A. Combination therapy using TMEM16A and PD-L1 inhibitors may improve the survival rate of HNSCC patients, especially those resistant to anti-EGFR inhibitor treatment. To the best of our knowledge, this is the first review to propose a biological validation that combines immune checkpoint inhibition with TMEM16A inhibition.

Long-term survival of an adult patient with undifferentiated embryonal sarcoma of the liver with multidisciplinary treatment: a case report and literature review

Background

Undifferentiated embryonal sarcoma of the liver (UESL) primarily occurs in children; it is rarely seen in adults and appears to have a poor prognosis. However, in recent years, some cases indicated that long-term survival was possible due to a combination of multiple surgeries, chemotherapy, and liver transplantation.

Case presentation

A 33-year-old female patient presented with a complaint of epigastric pain, for which she underwent a medical examination. Computed tomography (CT) and magnetic resonance imaging showed a cystic tumor in the right hepatic lobe, approximately 10 cm in size. During observation, the abdominal pain worsened, and a contrast-enhanced CT revealed that the tumor’s peripheral solid components increased in size and volume, suggesting a malignant tumor threatening hepatic rupture. Subsequently, transcatheter arterial embolization of the anterior and posterior segmental branches of the hepatic artery was performed, followed by right trisectionectomy. Histopathological and immunohistochemical examinations of the lesion revealed UESL. Two months after the surgery, we initiated sarcoma-directed chemotherapy with doxorubicin because of multiple metastases to the liver. After initiating the chemotherapy, she received another regimen using gemcitabine/docetaxel, eribulin, trabectedin, ifosfamide/mesna, pazopanib, and cisplatin. During the chemotherapy, she underwent palliative surgery twice due to the progressive disease. She lived for 49 months after the initial operation.

Conclusions

Improved long-term survival was achieved in an adult patient with UESL after multidisciplinary therapy, involving a combination of three surgical procedures and several chemotherapies.

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.

Biological effects and regulation of IGFBP5 in breast cancer

The insulin-like growth factor receptor (IGF1R) pathway plays an important role in cancer progression. In breast cancer, the IGF1R pathway is linked to estrogen-dependent signaling. Regulation of IGF1R activity is complex and involves the actions of its ligands IGF1 and IGF2 and those of IGF-binding proteins (IGFBPs). Six IGFBPs are known that share the ability to form complexes with the IGFs, by which they control the bioavailability of these ligands. Besides, each of the IGFBPs have specific features. In this review, the focus lies on the biological effects and regulation of IGFBP5 in breast cancer. In breast cancer, estrogen is a critical regulator of IGFBP5 transcription. It exerts its effect through an intergenic enhancer loop that is part of the chromosomal breast cancer susceptibility region 2q35. The biological effects of IGFBP5 depend upon the cellular context. By inhibiting or promoting IGF1R signaling, IGFBP5 can either act as a tumor suppressor or promoter. Additionally, IGFBP5 possesses IGF-independent activities, which contribute to the complexity by which IGFBP5 interferes with cancer cell behavior.

Cinobufagin Exerts Anticancer Activity in Oral Squamous Cell Carcinoma Cells through Downregulation of ANO1

Anoctamin1 (ANO1), a calcium-activated chloride channel, is frequently overexpressed in several cancers, including oral squamous cell carcinoma (OSCC). OSCC is a highly aggressive cancer and the most common oral malignancy. ANO1 has been proposed as a potential candidate for targeted anticancer therapy. In this study, we performed a cell-based screening to identify novel regulators leading to the downregulation of ANO1, and discovered cinobufagin, which downregulated ANO1 expression in oral squamous cell carcinoma CAL-27 cells. ANO1 protein levels were significantly reduced by cinobufagin in a dose-dependent manner with an IC₅₀ value of ~26 nM. Unlike previous ANO1 inhibitors, short-term (≤10 min) exposure to cinobufagin did not alter ANO1 chloride channel activity and ANO1-dependent intestinal smooth muscle contraction, whereas long-term (24 h) exposure to cinobufagin significantly reduced phosphorylation of STAT3 and mRNA expression of ANO1 in CAL-27 cells. Notably, cinobufagin inhibited cell proliferation of CAL-27 cells expressing high levels of ANO1 more potently than that of ANO1 knockout CAL-27 cells. In addition, cinobufagin significantly reduced cell migration and induced caspase-3 activation and PARP cleavage in CAL-27 cells. These results suggest that downregulation of ANO1 by cinobufagin is a potential mechanism for the anticancer effect of cinobufagin in OSCC.

DOG1 expression is common in human tumors: A tissue microarray study on more than 15,000 tissue samples

DOG1 (Discovered on GIST1) is a voltage-gated calcium-activated chloride and bicarbonate channel that is highly expressed in interstitial cells of Cajal and in gastrointestinal stromal tumors (GIST) derived from Cajal cells. To systematically determine in what tumor entities and normal tissue types DOG1 may be further expressed, a tissue microarray (TMA) containing 15,965 samples from 121 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. DOG1 immunostaining was found in 67 tumor types including GIST (95.7%), esophageal squamous cell carcinoma (31.9%), pancreatic ductal adenocarcinoma (33.6%), adenocarcinoma of the Papilla Vateri (20%), squamous cell carcinoma of the vulva (15.8%) and the oral cavity (15.3%), mucinous ovarian cancer (15.3%), esophageal adenocarcinoma (12.5%), endometrioid endometrial cancer (12.1%), neuroendocrine carcinoma of the colon (11.1%) and diffuse gastric adenocarcinoma (11%). Low level-DOG1 immunostaining was seen in 17 additional tumor entities. DOG1 expression was unrelated to histopathological parameters of tumor aggressiveness and/or patient prognosis in cancers of the breast (n = 1002), urinary bladder (975), ovary (469), endometrium (173), stomach (233), and thyroid gland (512). High DOG1 expression was linked to estrogen receptor expression in breast cancer (p < 0.0001) and absence of HPV infection in squamous cell carcinomas (p = 0.0008). In conclusion, our data identify several tumor entities that can show DOG1 expression levels at similar levels as in GIST. Although DOG1 is tightly linked to a diagnosis of GIST in spindle cell tumors, the differential diagnosis is much broader in DOG1 positive epithelioid neoplasms.

Expression of TMEM16A in Colorectal Cancer and Its Correlation With Clinical and Pathological Parameters

TMEM16A is a recently identified calcium-activated chloride channel (CaCC) and its overexpression contributes to tumorigenesis and progression in several human malignancies. However, little is known about expression of TMEM16A and its clinical significance in colorectal cancer (CRC). TMEM16A mRNA expression was determined by quantitative real time-PCR (qRT-PCR) in 67 CRC tissues and 24 para-carcinoma tissues. TMEM16A protein expression was performed by immunohistochemistry in 80 CRC tissues. The correlation between TMEM16A expression and clinicopathological parameters, and known genes and proteins involved in CRC was analyzed. The results showed that TMEM16A mRNA expression was frequently detected in 51 CRC tissues (76%), whereas TMEM16A protein expression was determined at a relatively lower frequency (26%). TMEM16A mRNA expression in tumor tissues was higher than its expression in normal para-carcinoma tissues (P < 0.05). TMEM16A mRNA expression was significantly correlated with TNM stage (p = 0.039) and status of lymph node metastasis (p = 0.047). In addition, there was a strong positive correlation between TMEM16A mRNA expression and MSH2 protein. More importantly, TMEM16A protein expression was positively associated with KRAS mutation, and negatively correlated with mutant p53 protein. Logistic regression analysis demonstrated that TMEM16A mRNA expression was an important independent predictive factor of lymph node metastasis (OR = 16.38, CI: 1.91–140.27, p = 0.01). TMEM16A mRNA and protein expression was not significantly related with patient survival. Our findings provide original evidence demonstrating TMEM16A mRNA expression can be a novel predictive marker of lymph node metastasis and TMEM16A protein expression may be an important regulator of tumor proliferation and metastasis in CRC.

ANO1 Expression Orchestrates p27Kip1/MCL1-Mediated Signaling in Head and Neck Squamous Cell Carcinoma

Simple Summary

Our aim was to elucidate the molecular mechanisms of how ANO1 contributes to oncogenic processes in squamous cell carcinoma of the head and neck (HNSCC). We explored transcriptional programs influenced by ANO1 knockdown in patient-derived UT-SCC cell lines with 11q13 amplification and ANO1 overexpression. ANO1 depletion led to downregulation of broad pro-survival BCL2 family protein members, including MCL1, and simultaneously induced upregulation of the cell cycle inhibitor p27^Kip1 and its redistribution from the cytoplasm into the nucleus in the studied HNSCC cells. Gene set enrichment analysis highlighted pathways associated with perturbed cell cycle and apoptosis in the ANO1-depleted samples. Silencing of ANO1 and application of an ANO1-targeting small-molecule inhibitor led to ANO1 degradation and reduction of cell viability. These findings suggest that ANO1 has drug target potential that deserves further evaluation in preclinical in vivo models.

Abstract

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous group of tumors that derive from the mucosal epithelium of the upper aerodigestive tract and present high mortality rate. Lack of efficient targeted-therapies and biomarkers towards patients’ stratification are caveats in the disease treatment. Anoctamin 1 (ANO1) gene is amplified in 30% of HNSCC cases. Evidence suggests involvement of ANO1 in proliferation, migration, and evasion of apoptosis; however, the exact mechanisms remain elusive. Aim of this study was to unravel the ANO1-dependent transcriptional programs and expand the existing knowledge of ANO1 contribution to oncogenesis and drug response in HNSCC. We cultured two HNSCC cell lines established from primary tumors harboring amplification and high expression of ANO1 in three-dimensional collagen. Differential expression analysis of ANO1-depleted HNSCC cells demonstrated downregulation of MCL1 and simultaneous upregulation of p27^Kip1 expression. Suppressing ANO1 expression led to redistribution of p27^Kip1 from the cytoplasm to the nucleus and associated with a cell cycle arrested phenotype. ANO1 silencing or pharmacological inhibition resulted in reduction of cell viability and ANO1 protein levels, as well as suppression of pro-survival BCL2 family proteins. Collectively, these data provide insights of ANO1 involvement in HNSCC carcinogenesis and support the rationale that ANO1 is an actionable drug target.

Prognostic significance of ANO1 expression in cancers

BACKGROUND

Anoctamin-1 (ANO1) plays a pivotal role in cancer progression. A meta-analysis was conducted to assess the potential prognostic role of ANO1 in cancers.

METHODS

A total of 1760 patients from 7 eligible studies were included into the analysis. Pooled hazard ratios or odds ratios were extracted and calculated with a random-effects model, and analyses of heterogeneity bias were conducted.

RESULTS

Our results showed that over expression of ANO1 was significantly correlated with poor overall survival in all cancers (HR = 1.52; 95% CI: 1.19-1.92; P = .0006). Subgroup analysis indicated that there was a significant association between over expression of ANO1 and poor prognosis breast cancer (HR = 3.24; 95% CI: 1.74-6.04), head and neck squamous cell carcinoma (HR = 1.14; 95% CI: 1.00-1.30), esophageal squamous cell carcinoma (HR = 1.93; 95% CI: 1.07-3.50), gastric cancer (HR = 1.62; 95% CI: 1.12-2.34) and colorectal cancer (HR = 1.38; 95% CI: 1.03-1.85). In addition, over expression of ANO1 was not associated with TNM stage, histological grade, lymph node metastasis, tumor size, age and gender. However, ANO1 was significantly associated with human epidermal growth factor receptor 2, but not associated with progesterone receptor or estrogen receptor in breast cancer.

CONCLUSIONS

Our results indicate that ANO1 can be a predictive factor for prognosis of cancer.

Anti-glioma effects of 2-aminothiophene-3-carboxamide derivatives, ANO1 channel blockers

Anoctamin1 (ANO1), a calcium-activated chloride ion channel (CaCC), is associated with various physiological functions including cancer progression and metastasis/invasion. ANO1 has been considered as a promising target for cancer therapeutics as ANO1 is over-expressed in a variety of cancers including glioblastoma (GBM) and inhibition of ANO1 has been reported to suppress cell proliferation, migration and invasion in GBM. GBM is one of the most common and aggressive cancers with poor prognosis with median survival for 15 months. Lack of effective treatment options against GBM emphasizes urgent necessity of effective GBM therapeutics. In an effort to discover potent and selective ANO1 inhibitors capable of inhibiting GBM cells, we have designed and synthesized a series of new 2-aminothiophene-3-carboxamide derivatives and performed SAR studies using both fluorescent cellular membrane potential assay and whole-cell patch-clamp recording. We observed that among these substances, 9c and 10q strongly suppress ANO1 channel activities and possess remarkable selectivity over ANO2. Unique structural feature of 10q, a cyclopentane-fused thiophene-3-carboxamide derivative, is the presence of benzoylthiourea functionality which dramatically contributes to activity. Both 9c and 10q suppress more strongly proliferation of GBM cells than four reference compounds including 3, Ani-9 and are also capable of inhibiting much more strongly colony formation than reference compounds in both 2D colony formation assay and 3D soft agar assay using U251 glioma cells. In addition, 9c and 10q suppress far more strongly migration/invasion of GBM cells than reference compounds. We, for the first time, found that the combination of ANO1 inhibitor (9c or 3) and temozolomide (TMZ) brings about remarkable synergistic effects in suppressing proliferation of GBM cells. Our study may provide an insight into designing selective and potent ANO1 inhibitors aiming at GBM treatment.

FAM83H and SCRIB stabilize β-catenin and stimulate progression of gastric carcinoma

FAM83H primarily is known for its function in tooth development. Recently, a role for FAM83H in tumorigenesis, conjunction with MYC and β-catenin, has been suggested. Analysis of public data indicates that FAM83H expression is closely associated with SCRIB expression in human gastric cancers. Therefore, this study investigated the roles of FAM83H and SCRIB in 200 human gastric cancers and gastric cancer cells. In human gastric carcinomas, both the individual and combined expression patterns of the nuclear FAM83H and SCRIB were independent indicators of shorter survival of gastric carcinoma patients. In MKN-45 and NCI-N87 gastric cancer cells, the expression of FAM83H and SCRIB were associated with proliferation and invasiveness of cells. FAM83H-mediated in vivo tumor growth was attenuated with knock-down of SCRIB. Moreover, immunoprecipitation indicates that FAM83H, SCRIB, and β-catenin, form a complex, and knock-down of either FAM83H or SCRIB accelerated proteasomal degradation of β-catenin. In conclusion, this study has found that the individual and combined expression patterns of nuclear FAM83H and SCRIB are prognostic indicators of gastric carcinomas and further suggests that FAM83H and SCRIB are involved in the progression of gastric carcinomas by stabilizing β-catenin.

Morphological features useful in the differential diagnosis between undifferentiated carcinoma and gastrointestinal stromal tumor

Undifferentiated (sarcomatoid) carcinomas may closely mimic gastrointestinal stromal tumors (GISTs) due to possible histological and immunohistochemical overlap between these two entities. To avoid unnecessary employment of a wide spectrum of immunohistochemical stainings and molecular genetics and thus decrease costs, finding simple morphological features to target further investigation of such neoplasms of the gastrointestinal tract would be helpful. Five cases classified as undifferentiated (sarcomatoid) carcinomas with a definite proof of the diagnosis, i. e. the presence of a differentiated carcinomatous component, were retrieved from archives of several institutions. For comparison, 84 cases of GIST mutated in KIT or PDGFRA genes served as the control group. Hematoxylin and eosin stained slides were evaluated for the presence of patterns which might discriminate between sarcomatoid carcinoma and GIST. Lymphatic invasion and entrapment of fat tissue strongly favor the diagnosis of undifferentiated carcinoma, as it was found in all or almost all cases of undifferentiated carcinoma, but in no GIST. Alternation of low- and high- grade areas, formation of angiosarcomatous-like spaces, and the presence of yolk sac-like areas were also detected in all cases of undifferentiated carcinoma, but only in 1.2%, 2.4% and 7.2% of the GISTs, respectively. Furthermore, DOG1 was negative in all cases of undifferentiated carcinoma. According to this study, the presence of the histological findings listed above should prompt extensive tumor sampling in order to find a differentiated carcinomatous component. However, due to the small number of cases of undifferentiated carcinoma available for the study, a larger multi-institutional study is warranted.

Suppression of CaMKIIβ Inhibits ANO1-Mediated Glioblastoma Progression

ANO1, a Ca²⁺-activated chloride channel, is highly expressed in glioblastoma cells and its surface expression is involved in their migration and invasion. However, the regulation of ANO1 surface expression in glioblastoma cells is largely unknown. In this study, we found that Ca²⁺/Calmodulin-dependent protein kinase II (CaMKII) β specifically enhances the surface expression and channel activity of ANO1 in U251 glioblastoma cells. When KN-93, a CaMKII inhibitor, was used to treat U251 cells, the surface expression and channel activity of ANO1 were significantly reduced. Only CaMKIIβ, among the four CaMKII isoforms, increased the surface expression and channel activity of ANO1 in a heterologous expression system. Additionally, gene silencing of CaMKIIβ suppressed the surface expression and channel activity of ANO1 in U251 cells. Moreover, gene silencing of CaMKIIβ or ANO1 prominently reduced the migration and invasion of U251 and U87 MG glioblastoma cells. We thus conclude that CaMKIIβ plays a specific role in the surface expression of ANO1 and in the ANO1-mediated tumorigenic properties of glioblastoma cells, such as migration and invasion.

FAM83H is involved in stabilization of β-catenin and progression of osteosarcomas

Background

FAM83H was initially identified as a protein essential for dental enamel formation. Recent reports have shown that FAM83H is also involved in the progression of human cancers in conjunction with tumor-associated molecules, such as MYC and β-catenin. However, the role of FAM83H in sarcoma has not yet been investigated.

Methods

The expression and roles of FAM83H and β-catenin were evaluated in human osteosarcomas from 34 patients and osteosarcoma cells.

Results

The expression of nuclear FAM83H, cytoplasmic FAM83H, and β-catenin were significantly associated with each other and significantly associated with shorter survival of osteosarcoma patients by univariate analysis. In multivariate analysis, cytoplasmic expression of FAM83H was an independent indicator of shorter survival of osteosarcoma patients (overall survival; P <  0.001, relapse-free survival; P <  0.001). In U2OS, MG63, and KHOS/NP osteosarcoma cells, the knock-down of FAM83H decreased proliferation and invasion activity and overexpression of FAM83H increased proliferation and invasion activity. In KHOS/NP cells, knock-down of FAM83H significantly inhibited, and overexpression of FAM83H significantly increased in vivo growth of cells. In addition, the knock-down of FAM83H decreased protein expression of β-catenin, active β-catenin, cyclin D1, vimentin, and snail. Overexpression of FAM83H increased protein expression of β-catenin, active β-catenin, cyclin D1, vimentin, and snail. However, the expression of β-catenin mRNA was not significantly altered with knock-down or overexpression of FAM83H. In addition, FAM83H and β-catenin shown to directly interact via immunoprecipitation and nuclear and cytoplasmic localization of β-catenin was decreased with knock-down of FAM83H. Moreover, the ubiquitination and proteasomal degradation of β-catenin was increased with knock-down of FAM83H.

Conclusions

This study suggests that FAM83H is involved in the progression of osteosarcomas via a mechanism involving the stabilization of β-catenin and the promotion of proliferation and invasiveness of osteosarcomas.

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.

SIRT6 Is Involved in the Progression of Ovarian Carcinomas via β-Catenin-Mediated Epithelial to Mesenchymal Transition

SIRT6 is involved in various cellular signaling pathways including those involved in tumorigenesis in association with β-catenin. However, the role of SIRT6 in tumorigenesis has been controversially reported and the studies on the role of SIRT6 in ovarian cancers is limited. In this study, we evaluated the expression and roles of SIRT6 in conjunction with the expression of active β-catenin in 104 human ovarian carcinomas and ovarian cancer cells. In human ovarian carcinomas, the expressions of SIRT6 and active β-catenin were associated with higher tumor stage, higher histologic grade, and platinum-resistance. Moreover, nuclear expression of SIRT6 (104 ovarian carcinomas; P = 0.010, 63 high-grade serous carcinomas; P = 0.040), and activated β-catenin (104 ovarian carcinomas; P = 0.013, 63 high-grade serous carcinomas; P = 0.005) were independent indicators of shorter overall survival of ovarian carcinoma patients in multivariate analysis. In OVCAR3 and OVCAR5 ovarian cancer cells, knock-down of SIRT6 significantly inhibited the migration and invasion of cells, but did not inhibit the proliferation of cells. SIRT6-mediated invasiveness of ovarian cancer cells was associated with the expression of epithelial-to-mesenchymal transition-related signaling molecules such as snail, vimentin, N-cadherin, E-cadherin, and activated β-catenin. Especially, SIRT6-mediated increase of invasiveness and activation of epithelial-to-mesenchymal transition signaling was attenuated by knock-down of β-catenin. In conclusion, this study suggests that SIRT6-β-catenin signaling is involved in the epithelial-to-mesenchymal transition of ovarian cancer cells, and the expression of SIRT6 and active β-catenin might be used as indicators of poor prognosis of ovarian carcinoma patients. In addition, our results suggest that SIRT6-β-catenin signaling might be a new therapeutic target of ovarian carcinomas.

Identification of candidate target genes for endometrial cancer, such as ANO1, using weighted gene co-expression network analysis

Network-based systems biology has become an important method for analysis of high-throughput gene expression data and gene function mining. The aim of the present study was to implement a weighted gene co-expression network analysis to screen genes that were significantly correlated with the clinical phenotype of endometrial cancer based on data from The Cancer Genome Atlas. By using the function ‘pickSoftThreshold’ in R software, the optimum soft thresholding power was determined to be 4. Subsequently, a total of 2,414 expressed genes were identified among 19,791 genes from 506 samples, which were divided into 24 modules according to the different expression patterns. After analyzing the correlation between the gene expression in these 24 modules and the clinical phenotype of endometrial cancer, the anoctamin 1 (ANO1) gene was selected for further analysis. The Chi-squared test indicated that ANO1 was significantly associated with age (P=0.047), histological type (P<0.001), clinical stage (P<0.001), pathological grade (P<0.001) and positive peritoneal washing (P=0.001) of endometrial carcinoma. Kaplan-Meier survival analysis revealed that a high level of ANO1 was significantly associated with a good prognosis for endometrial cancer patients. Univariate and multivariate Cox regression analysis indicated that ANO1 is an independent prognostic factor in endometrial cancer. Further characterization of the most relevant module containing ANO1 with the database for annotation, visualization and integrated discovery tool suggested that ANO1 is involved in various pathways, including metabolic pathways. The present study suggests that ANO1 may be a potential marker for good prognosis in endometrial cancer.

Synthesis and biological evaluation of novel Ani9 derivatives as potent and selective ANO1 inhibitors

Anoctamin 1 (ANO1), a calcium-activated chloride channel, is highly expressed and amplified in a number of carcinomas including breast, pancreatic and prostate cancers. Downregulation of ANO1 expression and function significantly inhibits cell proliferation, migration, and invasion of various cancer cell lines. Development of potent and selective ANO1 inhibitors is currently desirable, which may provide a new strategy for cancer treatment. Our previous study revealed a new class of ANO1 inhibitor, (E)-2-(4-chloro-2-methylphenoxy)-N'-(2-methoxybenzylidene)acetohydrazide (Ani9) and structural optimization via chemical modification of Ani9 basic skeleton was undertaken for the development of more potent and specific inhibitors of ANO1. Structure-activity relationship studies with newly synthesized derivatives revealed a number of potent ANO1 inhibitors, among which 5f is the most potent inhibitor with an IC₅₀ value of 22 nM. The selectivity analyses showed that 5f has excellent selectivity to ANO1 (>1000-fold over ANO2). In cellular assays, 5f significantly inhibited cell proliferation of PC3, MCF7, and BxPC3 cells expressing high levels of ANO1. In addition, 5f strongly reduced the protein levels of ANO1 in PC3 cells. This study will be useful in the development of ANO1 inhibitors for treatment of cancer and other ANO1-related diseases.