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Potassium channels are often dysregulated in tumours of the gastrointestinal (GI) tract. Among them, the voltage-dependent channel K

Supplementary Table S1 shows nucleotide sequence of the scDb-hERG1-β1. Supplementary Table S2 reports a list of primers. Supplementary Figure S1 dot blot and Coomassie staining of different scDb-hERG1-β1 clones. Supplementary Figure S2 shows peptide ELISA assay performed using different peptides. Supplementary Figure S3 shows Figure S3 cell ELISA assay performed using different cancer cell lines. Supplementary Figure S4 shows dose-dependence curves of different cell lines treated with scDb-hERG1-β1. Supplementary Figure S5 shows cell cycle plots. Supplementary Figure S6 shows spheroid growth curves of different cancer cell lines. Supplementary Figure S7 shows microscopic appearance of spheroids of PANC-1, HCT116 and MIAPaca 2 cells. Supplementary Figure S8 shows sequence alignments

Non Linear Contrast Mode imaging of mouse kidneys 3 hours after the injection of 8mg/kg of scDb

mAbs, either mono- or bispecific (bsAb), represent one of the most successful approaches to treat many types of malignancies. However, there are certain limitations to the use of full length mAbs for clinical applications, which can be overcome by engineered antibody fragments. The aim of this study was to develop a small bsAb, in the format of a single-chain diabody (scDb), to efficiently target two proteins, the hERG1 potassium channel and the β1 subunit of integrin receptors, which specifically form a macromolecular complex in cancer cells. We provide evidence that the scDb we produced binds to the hERG1/β1 complex in cancer cells and tissues, but does not bind to the hERG1 channel in nonpathologic tissues, in particular the heart. The scDb-hERG1-β1 (i) downregulates the formation of the hERG1/β1 complex, (ii) inhibits Akt phosphorylation and HIF-1α expression, and (iii) decreases cell survival, proliferation, and migration in vitro. These effects only occur in cancer cells (either colon, pancreatic, or breast), but not in normal cells. In vivo, the scDb-hERG1-β1 shows a good pharmacokinetic profile, with a half-life of 13.5 hours and no general, cardiac, or renal toxicity when injected intravenously up to the dose of 8 mg/kg. The scDb-hERG1-β1 accumulates into subcutaneous xenografted tumors, arising from either colon or pancreatic human cancer cells, and induces a reduction of tumor growth and vascularization. Overall, the scDb-hERG1-β1 represents an innovative single-chain bispecific antibody for therapeutic applications in solid cancers that overexpress the hERG1/β1 integrin signaling complex.

Purpose: hERG1 channels are aberrantly expressed in several types of human cancers, where they affect different aspects of cancer cell behavior. A thorough analysis of the functional role and clinical significance of hERG1 channels in gastric cancer is still lacking.Experimental Design: hERG1 expression was tested in a wide (508 samples) Italian cohort of surgically resected patients with gastric cancer, by immunohistochemistry and real-time quantitative PCR. The functional link between hERG1 and the VEGF-A was studied in different gastric cancer cell lines. The effects of hERG1 and VEGF-A inhibition were evaluated in vivo in xenograft mouse models.Results: hERG1 was positive in 69% of the patients and positivity correlated with Lauren's intestinal type, fundus localization of the tumor, G1–G2 grading, I and II tumor—node—metastasis stage, and VEGF-A expression. hERG1 activity modulated VEGF-A secretion, through an AKT-dependent regulation of the transcriptional activity of the hypoxia inducible factor. Treatment of immunodeficient mice xenografted with human gastric cancer cells, with a combination of hERG1 blockers and anti-VEGF-A antibodies, impaired tumor growth more than single-drug treatments.Conclusion: Our results show that hERG1 (i) is aberrantly expressed in human gastric cancer since its early stages; (ii) drives an intracellular pathway leading to VEGF-A secretion; (iii) can be exploited to identify a gastric cancer patients' group where a combined treatment with antiangiogenic drugs and noncardiotoxic hERG1 inhibitors could be proposed. Clin Cancer Res; 20(6); 1502–12. ©2014 AACR.

PDF file - 738K, ADDITIONAL MATERIALS AND METHODS, FIGURES AND TABLES Fig S1- Immunohistochemical detection of hERG1 protein in GC specimens. Fig S2- hERG1 protein expression in GC primary samples. Figure S3- hERG1b characterization in primary GC. Fig S4- hERG1 protein expression in GC cell lines. Fig S5- hERG1USO protein expression in GC cell lines. Fig S6- Effects of the PI3K/Akt inhibition on VEGF-A secretion in AKG cells under normoxic conditions. Fig S7- Immunohistochemical detection of hERG1 protein in GC specimens. Fig S8- Immunohistochemical detection of hERG1 protein in GC specimens. Fig S9- VEGF-A and hERG1 expression in GC samples. Fig S10. Interaction analyses on OS between hERG1 and other clinical and pathological parameters (Forest Plot). Fig S11- Comparison between herg1a mRNA and hERG1A protein expression in GC samples. Table S1- Antibodies used for IHC experiments described in the main text. Table S2- Primer Sequences. Primers were used for methylation analysis and RQ-PCR. Table S3- Cell lines used in the experiments described in the main text. Table S4- hERG1 expression in AKG cells treated with alpha-hERG1 siRNAs and WAY hERG1 blocker. Table S5- VEGF-A and Kv 1.3 expression in AKG cells treated with alpha-hERG1 siRNAs, WAY hERG1 blocker and alpha-vegf-a siRNA. Table S6- Characteristics of patients excluded and included into the statistical analyses and distributions of clinical and pathological variables after multiple imputation of missing values.

Pancreatic ductal adenocarcinoma (PDAC) represents an unmet medical need. Difficult/late diagnosis as well as the poor efficacy and high toxicity of chemotherapeutic drugs result in dismal prognosis. With the aim of improving the treatment outcome of PDAC, we tested the effect of combining Gemcitabine with a novel single chain bispecific antibody (scDb) targeting the cancer-specific hERG1/β1 integrin complex. First, using the scDb (scDb-hERG1-β1) in immunohistochemistry (IHC), Western blot (WB) analysis and immunofluorescence (IF), we confirmed the presence of the hERG1/β1 integrin complex in primary PDAC samples and PDAC cell lines. Combining Gemcitabine with scDb-hERG1-β1 improved its cytotoxicity on all PDAC cells tested in vitro. We also tested the combination treatment in vivo, using an orthotopic xenograft mouse model involving ultrasound-guided injection of PDAC cells. We first demonstrated good penetration of the scDb-hERG1-β1 conjugated with indocyanine green (ICG) into tumour masses by photoacoustic (PA) imaging. Next, we tested the effects of the combination at either therapeutic or sub-optimal doses of Gemcitabine (25 or 5 mg/kg, respectively). The combination of scDb-hERG1-β1 and sub-optimal doses of Gemcitabine reduced the tumour masses to the same extent as the therapeutic doses of Gemcitabine administrated alone; yielded increased survival; and was accompanied by minimised side effects (toxicity). These data pave the way for a novel therapeutic approach to PDAC, based on the combination of low doses of a chemotherapeutic drug (to minimize adverse side effects and the onset of resistance) and the novel scDb-hERG1-β1 targeting the hERG1/β1 integrin complex as neoantigen.

mAbs, either mono- or bispecific (bsAb), represent one of the most successful approaches to treat many types of malignancies. However, there are certain limitations to the use of full length mAbs for clinical applications, which can be overcome by engineered antibody fragments. The aim of this study was to develop a small bsAb, in the format of a single-chain diabody (scDb), to efficiently target two proteins, the hERG1 potassium channel and the β1 subunit of integrin receptors, which specifically form a macromolecular complex in cancer cells. We provide evidence that the scDb we produced binds to the hERG1/β1 complex in cancer cells and tissues, but does not bind to the hERG1 channel in nonpathologic tissues, in particular the heart. The scDb-hERG1-β1 (i) downregulates the formation of the hERG1/β1 complex, (ii) inhibits Akt phosphorylation and HIF-1α expression, and (iii) decreases cell survival, proliferation, and migration in vitro. These effects only occur in cancer cells (either colon, pancreatic, or breast), but not in normal cells. In vivo, the scDb-hERG1-β1 shows a good pharmacokinetic profile, with a half-life of 13.5 hours and no general, cardiac, or renal toxicity when injected intravenously up to the dose of 8 mg/kg. The scDb-hERG1-β1 accumulates into subcutaneous xenografted tumors, arising from either colon or pancreatic human cancer cells, and induces a reduction of tumor growth and vascularization. Overall, the scDb-hERG1-β1 represents an innovative single-chain bispecific antibody for therapeutic applications in solid cancers that overexpress the hERG1/β1 integrin signaling complex.

Electrolyte disorders are a frequent finding in cancer patients. In the majority of cases the etiologies of such disorders are common to all cancer types (i.e. diuretic-induced hyponatremia or hypokalemia). Sometimes, electrolyte disorders are caused by paraneoplastic syndromes or are due to cancer therapy. Potassium is one of the most important electrolytes of the human body since it is involved in the regulation of muscle contraction, maintenance of the integrity of the skeleton, blood pressure and nerve transmission as well as in the normal function of cells. Potassium homeostasis is strictly regulated since the gap between the recommended daily dietary intake (120 mEq/day) and the levels stored in the extracellular fluid (around 70 mEq) is huge. Alterations of potassium homeostasis are frequent in cancer patients as well alterations in potassium channels, the transmembrane proteins that mediate potassium fluxes within the cells. The present chapter is focused on the clinical significance of potassium homeostasis and potassium channels in patients with solid tumors.

We conducted a screening analysis to assess the presence of a characteristic extracellular circulating microRNAs (ci-miRNAs) profile in Behcet's syndrome (BS). Total RNA was extracted from platelets-free plasma (PFP) samples obtained from 16 BS patients and 18 healthy controls. Ci-miRNAs profiling was conducted by using dedicated Agilent microarray hybridization and data extraction technology. Statistical analysis of data extracted from microarray scanning revealed the deregulation of 36 ci-miRNAs, which turned out be differentially expressed between BS patients and healthy controls. Detailed experimental methods and data analysis were described here. The raw and normalized microarray data were deposited into Gene Expression Omnibus (GEO) under accession number {"type":"entrez-geo","attrs":{"text":"GSE145191","term_id":"145191"}}GSE145191.

Because of its high incidence and poor prognosis, colorectal cancer (CRC) represents an important health issue in several countries. As with other carcinomas, the so-called tumour microenvironment (TME) has been shown to play key roles in CRC progression and related therapeutical outcomes, even though a deeper understanding of the underlying molecular mechanisms is needed to devise new treatment strategies. For some years now, omics technologies and consolidated bioinformatics pipelines have allowed scientists to access large amounts of biologically relevant information, even when starting from small tissue samples, thus, in order to shed new light upon the role of the TME in CRC, we compared the gene expression profiles of 6 independent tumour tissues (all progressed towards metastatic disease) to the expression profile of the surrounding stromata. To do this, paraffin-embedded whole tissues were first microdissected to obtain samples enriched with tumour and stromal cells, respectively. Afterwards, RNA was extracted and analysed using a microarray-based approach. A thorough bioinformatics analysis was then carried out to identify transcripts differentially expressed between the two groups and possibly enriched functional terms. Overall, 193 genes were found to be significantly downregulated in tumours compared to the paired stromata. The functional analysis of the downregulated gene list revealed three principal macro areas of interest: the extracellular matrix, cell migration, and angiogenesis. Conversely, among the upregulated genes, the main alterations detected by the functional annotation were related to the ribosomal proteins (rProteins) of both the large (60S) and small (40S) subunits of the cytosolic ribosomes. Subsequent gene set enrichment analysis (GSEA) confirmed the massive overexpression of most cytosolic—but not mitochondrial—ribosome rProteins.

Simple Summary The voltage-gated sodium channel is a type of protein normally expressed in the ‘excitable’ tissues (nerves and muscles) of the body. Epithelial tissues (gut, lungs etc.), which are normally devoid of such a channel, express it at high levels upon becoming cancerous. This occurs also in colorectal cancer cells where the channel subtype is the embryonic (‘neonatal’) variant, nNav1.5. In colorectal cancer cells, as in other solid cancer cells, channel activity promotes invasiveness. However, there is little information on the status of nNav1.5 in human colorectal tissues and how this might relate to patient outcome. Here, we show (i) that nNav1.5 expression is much higher in cancer tissues compared with normal; (ii) that nNav1.5 co-occurs with several other biomarkers of pathological importance; and (iii) that disease-free survival of colorectal patients is inversely correlated with channel expression. In conclusion, nNav1.5 has combined diagnostic and therapeutic potential in clinical management of colorectal cancer. Abstract Voltage-gated Na+ channels (VGSCs) are expressed widely in human carcinomas and play a significant role in promoting cellular invasiveness and metastasis. However, human tissue-based studies and clinical characterization are lacking. In several carcinomas, including colorectal cancer (CRCa), the predominant VGSC is the neonatal splice variant of Nav1.5 (nNav1.5). The present study was designed to determine the expression patterns and clinical relevance of nNav1.5 protein in human CRCa tissues from patients with available clinicopathological history. The immunohistochemistry was made possible by the use of a polyclonal antibody (NESOpAb) specific for nNav1.5. The analysis showed that, compared with normal mucosa, nNav1.5 expression occurred in CRCa samples (i) at levels that were significantly higher and (ii) with a pattern that was more delineated (i.e., apical/basal or mixed). A surprisingly high level of nNav1.5 protein expression also occurred in adenomas, but this was mainly intracellular and diffuse. nNav1.5 showed a statistically significant association with TNM stage, highest expression being associated with TNM IV and metastatic status. Interestingly, nNav1.5 expression co-occurred with other biomarkers associated with metastasis, including hERG1, KCa3.1, VEGF-A, Glut1, and EGFR. Finally, univariate analysis showed that nNav1.5 expression had an impact on progression-free survival. We conclude (i) that nNav1.5 could represent a novel clinical biomarker (‘companion diagnostic’) useful to better stratify CRCa patients and (ii) that since nNav1.5 expression is functional, it could form the basis of anti-metastatic therapies including in combination with standard treatments.

Purpose Gastric cancer (GC) is still a relevant health issue worldwide. The identification of prognostic factors for progression of gastric dysplasia (GD), the main pre-cancerous lesion of the intestinal-type GC, is hence mandatory. Patients and methods A cohort of 83 GD endoscopic samples belonging to Italian subjects was collected. hERG1 expression was evaluated by immunohistochemistry and scored 0-3, depending on the percentage of stained cells. Expression data were analysed in conjunction with clinico-pathological and survival data. Results hERG1 turned out to be expressed in 67.47% (56 out of 83) of the GD samples. hERG1 expression was higher in high-grade GD compared to low-grade GD (29 out of 39, 74.36% vs 27 out of 44, 61.36%), although the statistical significance was not reached (P=0.246). No association emerged between hERG1 expression and clinical features of the patients (age, gender, localization, H. pylori infection, gastritis and intestinal metaplasia). In a subset of cases for which sequential samples of gastric lesions (from GD to Early Gastric Cancer and Advanced Gastric Cancer) were available, hERG1 expression was maintained in all the steps of gastric carcinogenesis from GD onwards. A general trend to increased expression in advanced lesions was observed. hERG1 score had a statistically significant impact on both Progression-Free Survival (P=0.018) and Overall Survival (P=0.031). In particular, patients displaying a high hERG1 score have a shorter survival. Conclusion hERG1 is aberrantly expressed in human GD samples and has an impact on both PFS and OS, hence representing a novel prognostic marker for progression of GD towards GC of the intestinal histotype. Once properly validated, hERG1 detection could be included in the clinical practice, during endoscopic surveillance protocols, for the management of GD at higher risk of progression, as already proposed for Barrett's oesophagus.

Ion channels are progressively emerging as a novel class of membrane proteins expressed in several types of human cancers and regulating the different aspects of cancer cell behavior. The metabolism of cancer cells, usually composed by a variable proportion of respiration, glycolysis, and glutaminolysis, leads to the excessive production of acidic metabolic products. The presence of these acidic metabolites inside the cells results in intracellular acidosis, and hinders survival and proliferation. For this reason, tumor cells activate mechanisms of pH control that produce a constitutive increase in intracellular pH (pH(i)) that is more acidic than the extracellular pH (pH(e)). This condition forms a perfect microenvironment for metastatic progression and may be permissive for some of the acquired characteristics of tumors. Recent analyses have revealed complex interconnections between oncogenic activation, ion channels, hypoxia signaling and metabolic pathways that are dysregulated in cancer. Here, we summarize the molecular mechanisms of the Warburg effect and hypoxia and their association. Moreover, we discuss the recent findings concerning the involvement of ion channels in various aspects of the Warburg effect and hypoxia, focusing on the role of Na(+) and K(+) channels in hypoxic and metabolic reprogramming in cancer.

Cancer is a highly heterogeneous disease in terms of both response to therapy and prognosis. The introduction of molecular tools and antibodies had a great impact on cancer management in recent years for both cancer diagnosis and therapy. Ion channels and transporters (ICT) are membrane proteins aberrantly expressed in several human cancers. ICT can now represent potential cancer biomarkers as well as targets for therapeutic and diagnostic purposes. In particular, we will discuss about the potential role of ICTs as biomarkers for solid cancers (evaluated either by immunohistochemistry or molecular biology techniques) and the potential use of antibodies for diagnosis.

ObjectivesBehçet’s syndrome (BS) is a rare systemic vasculitis often complicated by thrombotic events. Given the lack of validated biomarkers, BS diagnosis relies on clinical criteria.In search of novel biomarkers for BS diagnosis, we determined the profile of plasmatic circulating microRNAs (ci-miRNAs) in patients with BS compared with healthy controls (HCs).Methodsci-miRNA profile was evaluated by microarray in a screening cohort (16 patients with BS and 18 HCs) and then validated by poly(T) adaptor PCR (PTA-PCR) in a validation cohort (30 patients with BS and 30 HCs). Two disease control groups (30 patients with systemic lupus erythematosus (SLE) and 30 patients with giant cell arteritis (GCA) were also analysed.ResultsFrom the microarray screening, 29 deregulated (differentially expressed (DE)) human ci-miRNAs emerged. A hierarchical cluster analysis indicated that DE ci-miRNAs clearly segregated patients from controls, independently of clinical features. PTA-PCR analysis on the validation cohort confirmed the deregulation of miR-224-5p, miR-206 and miR-653-5p. The combined receiver operating characteristic (ROC) curve analyses showed that such ci-miRNAs discriminate BS from HCs (and BS with active vs inactive disease), as well as BS from patients with SLE and GCA.The functional annotation analyses (FAAs) showed that the most enriched pathways affected by DE ci-miRNAs (ie, cell–matrix interaction, oxidative stress and blood coagulation) are related to thrombo-inflammatory mechanisms. Accordingly, the expression of the three ci-miRNAs from the validation cohort significantly correlated with leucocyte reactive oxygen species production and plasma lipid peroxidation.ConclusionsThe ci-miRNA profile identified in this study may represent a novel, poorly invasive BS biomarker, while suggesting an epigenetic control of BS-related thrombo-inflammation.

The receptor for the luteinizing hormone (LH-R) is aberrantly over expressed in cancers of the reproductive system. To uncover whether LH-R over expression has a causative role in cancer, we generated a transgenic (TG) mouse which overexpresses the human LH-R (hLH-R) in the female reproductive tract, under the control of the oviduct-specific glycoprotein (OGP) mouse promoter (mogp-1). The transgene was highly expressed in the uterus, ovary and liver, but only in the uterus morphological and molecular alterations (increased proliferation and trans-differentiation in the endometrial layer) were detected. A transcriptomic analysis on the uteri of young TG mice showed an up regulation of genes involved in cell cycle control and a down regulation of genes related to the immune system and the metabolism of xenobiotics. Aged TG females developed tumor masses in the uteri, which resembled an Endometrial Cancer (EC). Microarray and immunohistochemistry data indicated the deregulation of signaling pathways which are known to be altered in human ECs. The analysis of a cohort of 126 human ECs showed that LH-R overexpression is associated with early-stage tumors. Overall, our data led support to conclude that LH-R overexpression may directly contribute to trigger the neoplastic transformation of the endometrium.

Patients with metastatic colorectal cancer (mCRC) are routinely screened for either K- and N-RAS to select the appropriate treatment. The present study aimed to evaluate the concordance between K- and NRAS status in the tissue (either primary tumor or metastasis) and the plasma of patients with mCRC and to identify the associations between K- and NRAS mutations in ctDNA and the clinicopathological parameters. Samples from a total of 31 patients with mCRC with measurable disease according to the Response Evaluation Criteria in Solid Tumors were analyzed. For all patients, K- and NRAS status was determined in the tissue by matrix-assisted laser desorption/ionization time of flight mass spectrometry. For the detection of RAS mutations in cell-free tumor DNA also defined as circulating tumor DNA (ctDNA), the OncoBEAM® RAS CRC kit (Sysmex Inostics) was used. A total of 6/31 tissue samples expressed wild-type KRAS, whereas 25/31 presented mutations. In addition, 7/31 plasma samples expressed wild-type KRAS, mutations were detected in 22/31 patients, and for 2/31 patients, the test did not provide a conclusive result. A total of 24/31 patients expressed wild-type NRAS, 6/31 had mutations and 1/21 was not informative. For the KRAS mutational status, a moderate concordance (agreement, 85.18%; Cohen's k, 0.513) between the tissue and plasma analysis was observed; for NRAS, a fair agreement (agreement, 83.33%; Cohen's k, 0.242) was obtained. In conclusion, both tissue and plasma analyses should be performed for the management of patients with mCRC. To better exploit the beads, emulsions, amplification, magnetics (BEAMing) technique in the clinical setting, studies aimed at determining the RAS status to monitor therapy and during follow-up are warranted.

Increasing evidence indicates that ion channels and transporters cooperate in regulating different aspects of tumor pathophysiology. In cancer cells, H+/HCO3- transporters usually invert the transmembrane pH gradient typically observed in non-neoplastic cells, which is thought to contribute to cancer malignancy. To what extent the pH-regulating transporters are functionally linked to K+ channels, which are central regulators of cell membrane potential (Vm), is unclear. We thus investigated in colorectal cancer cells the implication of the pH-regulating transporters and KV11.1 (also known as hERG1) in the pH modifications stimulated by integrin-dependent cell adhesion. Colorectal cancer cell lines (HCT 116 and HT 29) were seeded onto 1 integrin-dependent substrates, collagen I and fibronectin. This led to a transient cytoplasmic alkalinization, which peaked at 90 minutes of incubation, lasted approximately 180 min, and was inhibited by antibodies blocking the 1 integrin. The effect was sensitive to amiloride (10 µM) and cariporide (5 µM), suggesting that it was mainly caused by the activity of the Na+/H+ antiporter NHE1. Blocking KV11.1 with E4031 shows that channel activity contributed to modulate the 1 integrin-dependent pHi increase. Interestingly, both NHE1 and KV11.1 modulated the colorectal cancer cell motility triggered by 1 integrin-dependent adhesion. Finally, the 1 integrin subunit, KV11.1 and NHE1 co-immunoprecipitated in colorectal cancer cells seeded onto Collagen I, suggesting the formation of a macromolecular complex following integrin-mediated adhesion. We conclude that the interaction between KV11.1, NHE1 and β1 integrin contribute to regulate colorectal cancer intracellular pH in relation to the tumor microenvironment, suggesting novel pharmacological targets to counteract pro-invasive and, hence, pro-metastatic behavior in colorectal cancer.

Increasing evidence indicates that ion channels and transporters cooperate in regulating different aspects of tumor pathophysiology. In cancer cells, H+/HCO3- transporters usually invert the transmembrane pH gradient typically observed in non-neoplastic cells, which is thought to contribute to cancer malignancy. To what extent the pH-regulating transporters are functionally linked to K+ channels, which are central regulators of cell membrane potential (Vm), is unclear. We thus investigated in colorectal cancer cells the implication of the pH-regulating transporters and KV11.1 (also known as hERG1) in the pH modifications stimulated by integrin-dependent cell adhesion. Colorectal cancer cell lines (HCT 116 and HT 29) were seeded onto β1 integrin-dependent substrates, collagen I and fibronectin. This led to a transient cytoplasmic alkalinization, which peaked at 90 min of incubation, lasted approximately 180 min, and was inhibited by antibodies blocking the β1 integrin. The effect was sensitive to amiloride (10 µM) and cariporide (5 µM), suggesting that it was mainly caused by the activity of the Na+/H+ antiporter NHE1. Blocking KV11.1 with E4031 shows that channel activity contributed to modulate the β1 integrin-dependent pHi increase. Interestingly, both NHE1 and KV11.1 modulated the colorectal cancer cell motility triggered by β1 integrin-dependent adhesion. Finally, the β1 integrin subunit, KV11.1 and NHE1 co-immunoprecipitated in colorectal cancer cells seeded onto Collagen I, suggesting the formation of a macromolecular complex following integrin-mediated adhesion. We conclude that the interaction between KV11.1, NHE1, and β1 integrin contributes to regulate colorectal cancer intracellular pH in relation to the tumor microenvironment, suggesting novel pharmacological targets to counteract pro-invasive and, hence, pro-metastatic behavior in colorectal cancer.

Since the introduction of antiepidermal growth factor receptor (anti-EGFR) monoclonal antibodies (moAbs), the treatment of metastatic colorectal cancer (mCRC) has become crucially dependent on the mutation profile of the tumour over the last two decades. Recently, rechallenge strategy with cetuximab-based chemotherapy has demonstrated to be active in a subgroup of patients whose tumour maintained wild-type RAS and RAF status. In this setting, liquid biopsy may replace tissue sample for the identification of specific subgroups of pretreated patients that may benefit from the reintroduction of anti-EGFR moAbs. In November 2014, a 64-year-old man with IVB stage BRAF, KRAS and NRAS wild-type mCRC was admitted in our hospital. He received FOLFIRI cetuximab as first-line treatment with deep and long-lasting partial response (PR), followed by cetuximab maintenance therapy until January 2016. At the time of disease progression, FOLFIRI cetuximab regimen was reintroduced resulting in stabilization of disease and he continued with capecitabine cetuximab therapy until disease progression in October 2016. Then, the patient consecutively received FOLFOX bevacizumab, TAS-102, regorafenib and FOLFIRI followed by de Gramont maintenance treatment. Finally, he was retreated with FOLFIRI cetuximab with disease progression within 3 months and died in May 2019. During his clinical course, liquid biopsy detected two mutations: one in KRAS Cd.12 and one in NRAS Cd. 61. The longitudinal assessment of RAS status offers considerable advantages in order to avoid side effects and economic costs for ineffective treatment choices. Liquid biopsy could help better monitor the disease and provide molecularly guided treatments.

In the last decades, protein engineering has developed particularly in biotechnology and pharmaceutical field. In particular, the engineered antibody subclass has arisen. The single chain diabody format (scDb), conjugating small size with antigen specificity, offers versatility representing a gold standard for a variety of applications, spacing from research to diagnostics and therapy. Along with such advantages, comes the challenge of optimizing their production, improving expression systems, purification procedures and stability. All such parameters are detrimental for protein production in general and above all for recombinant antibody expression, which has to be fine-tuned, choosing a proper protein-expression host and adjusting expression protocols accordingly. In the present paper, we present data regarding the production and purification of a single chain diabody directed against the macromolecular complex hERG1/β1 integrin. We focus on the expression of clones deriving from the transformation of Pichia pastoris yeast cells. In particular, we compare two different clones arose from two separate transformation processes, demonstrating that both are suitable for proper protein expression. Moreover, we have set up an expression protocol and compared the yields obtained using two purification machines: Akta Pure and Akta Start, with a positive outcome.

Background The identification of early-stage colorectal cancer (CRC) with high risk of progression is one major clinical challenge, mainly due to lack of validated biomarkers. The aims of the present study were to analyze the prognostic impact of three molecular markers belonging to the ion channels and transporters family: the ether-à-go-go-related gene 1 (hERG1) and the calcium-activated KCa3.1 potassium channels, as well as the glucose transporter 1 (Glut-1); and to define the impact of adjuvant chemotherapy in conjunction with the abovementioned biomarkers, in a cohort of radically resected stage I–III CRC patients. Patients and methods The expressions of hERG1, KCa3.1, and Glut-1 were tested by immunohistochemistry on 162 surgical samples of nonmetastatic, stage I–III CRC patients. The median follow-up was 32 months. The association between biological markers, clinicopathological features, and survival outcomes was investigated by evaluating both disease-free survival and overall survival. Results Although no prognostic valence emerged for KCa3.1, evidence of a negative impact of hERG1 expression on survival outcomes was provided. On the contrary, Glut-1 expression had a positive impact. According to the results of the multivariate analysis, patients were stratified in four risk groups, based on TNM stage and hERG1/Glut-1 expression. After adjusting for adjuvant therapy, stage I and II, Glut-1-negative, and hERG1-positive patients showed the worst survival experience. Conclusion This study strongly indicates that the combination of hERG1 positivity and Glut-1 negativity behaves as a prognostic biomarker in radically resected CRC patients. This combination identifies a group of stage I and II CRC patients with a bad prognosis, even worse than that of stage III patients, regardless of adjuvant therapy accomplishment., Video abstract

Background: In search of novel biomarkers of response to bevacizumab in metastatic colorectal cancer (mCRC), we analyzed the expression and prognostic role of several proteins related to angiogenesis. Methods: A retrospective, multicenter study on 80 surgical samples from mCRC patients treated in first line with bevacizumab plus chemotherapy was accomplished. The following proteins were analyzed by immunohistochemistry: hERG1 potassium channel, β1-integrin, pAKT, NFkB, HIF-1α, HIF-2α, p53, VEGF-A, GLUT-1, and CA-IX. Data were analyzed in conjunction with the clinicopathological characteristics of the patients, KRAS status, response to bevacizumab, and follow-up. Results: (1) All the proteins were expressed in the samples, with statistically significant associations between HIF-1α and gender, HIF-2α and left colon, hERG1 and VEGF-A, β1-integrin and HIF-2α, GLUT-1 and both HIF-1α and HIF-2α, and CA-IX and VEGF-A. (2) At the univariate analysis, positivity for hERG1, VEGF-A, and the active form of HIF-2α (aHIF-2α), and the G3 histological grade showed a positive impact on progression-free survival (PFS). (3) hERG1 and aHIF-2α maintained their positive impact on PFS at the multivariate analysis. (4) hERG1 behaved as a protective factor for PFS independently on KRAS status. Conclusions: hERG1 and aHIF-2α might help to identify patients who would benefit from bevacizumab treatment.

Background Breast cancer (BC) is the most frequent malignancy among females worldwide. Despite several efforts and improvements in early diagnosis and treatment, there are still tumors characterized by an aggressive behavior due to unfavorable biology, thus quite difficult to treat. In this view, searching for novel potential biomarkers is mandatory. Among them, in the recent years data have been gathered addressing ion channel as important players in oncology. Methods A retrospective pilot study was performed on 40 BC samples by means of immunohistochemistry in order to evaluate hERG1 potassium channels expression in BC. Results We provide evidence that hERG1 is expressed in all the BC samples analyzed. hERG1 expression was significantly associated with molecular subtype with the highest expression in Luminal A and the lowest in basal-like tumors (p = 0.001), tumor grading (the highest hERG1 expression in well-moderate differentiated tumors, p = 0.020), estrogen receptors (high hERG1 expression in ER-positive samples, p = 0.008) and Ki67 proliferative index (high hERG1 scoring in samples with low proliferative index, p = 0.038). Also, a p value close to significance was noticed for the association between hERG1 and HER2 expression (p = 0.079). At the survival analysis, patients with high hERG1 expression turned out to have a longer progression-free survival, although statistical significance was not reached (p = 0.195). The same trend was observed analyzing local relapse free-survival (LRFS) and metastases-free survival (MFS): patients with higher hERG1 scoring had longer LRFS and MFS (p = 0.124 and p = 0.071, respectively). Conclusions The results of this pilot study provide the first evidence that the hERG1 protein is expressed in primary BC, and its expression associates with molecular subtype. hERG1 apparently behaves as a protective factor, since it contributes to identify a subset of patients with better outcome. Overall, these data suggest that hERG1 might be an additional tool for the management of BC, nevertheless further investigations are warranted to better clarify hERG1 role and clinical usefulness in BC.

Cancer is a disease with marked heterogeneity in both response to therapy and survival. Clinical and histopathological characteristics have long determined prognosis and therapy. The introduction of molecular diagnostics has heralded an explosion in new prognostic factors. Overall, histopathology, immunohistochemistry and molecular biology techniques have described important new prognostic subgroups in the different cancer categories.Ion channels and transporters (ICT) are a new class of membrane proteins which are aberrantly expressed in several types of human cancers. Besides regulating different aspect of cancer cell behavior, ICT can now represent novel cancer biomarkers. A summary of the data obtained so far and relative to breast, prostate, lung, colorectal, esophagus, pancreatic and gastric cancers are reported. Special emphasis is given to those studies aimed at relating specific ICT or a peculiar ICT profile with current diagnostic methods. Overall, we are close to exploit ICTs for diagnostic, prognostic or predictive purposes in cancer. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.

Background: hERG1 channels are aberrantly expressed in human cancers. The expression, functional role and clinical significance of hERG1 channels in pancreatic ductal adenocarcinoma (PDAC) is lacking. Methods: hERG1 expression was tested in PDAC primary samples assembled as tissue microarray by immunohistochemistry using an anti-hERG1 monoclonal antibody (α-hERG1-MoAb). The functional role of hERG1 was studied in PDAC cell lines and primary cultures. ERG1 expression during PDAC progression was studied in Pdx-1-Cre,LSL-KrasG12D/+,LSL-Trp53R175H/+ transgenic (KPC) mice. ERG1 expression in vivo was determined by optical imaging using Alexa-680-labelled α-hERG1-MoAb. Results: (i) hERG1 was expressed at high levels in 59% of primary PDAC; (ii) hERG1 blockade decreased PDAC cell growth and migration; (iii) hERG1 was physically and functionally linked to the Epidermal Growth Factor-Receptor pathway; (iv) in transgenic mice, ERG1 was expressed in PanIN lesions, reaching high expression levels in PDAC; (v) PDAC patients whose primary tumour showed high hERG1 expression had a worse prognosis; (vi) the α-hERG1-MoAb could detect PDAC in vivo. Conclusions: hERG1 regulates PDAC malignancy and its expression, once validated in a larger cohort also comprising of late-stage, non-surgically resected cases, may be exploited for diagnostic and prognostic purposes in PDAC either ex vivo or in vivo.

Objectives: Circulating Endothelial Progenitor Cells (cEPCs) have been reported to be dysfunctional in Diabetes Mellitus (DM) patients, accounting for the vascular damage and the ensuing high risk for cardiovascular disease (CVD) characteristic of this disease. The aim of the present study was to evaluate the number of circulating cEPCs in type 1 DM (T1DM) patients, without clinical vascular damage, of different ages and with different disease duration. Methods: An observational, clinical-based prospective study was performed on T1DM patients enrolled in two clinical centers. cEPCs were determined by flow cytometry, determining the number of CD34/CD133/VEGF-R2 positive cells within peripheral blood mononuclear cells (PBMC). Results: The number of cEPCs was lower in adult T1DM patients, whilst higher in childhood/young patients, compared to controls of the same age range. When patients were grouped into two age groups ( or < 20 years) (and categorized on the basis of the duration of the disease), the number of cEPCs in young (< 20 years) patients was higher compared with older subjects, regardless of disease duration. A subset of patients with very high cEPCs was identified in the

Purpose: Barrett’s esophagus (BE) is the sole precursor lesion of esophageal adenocarcinoma (EA) identified so far. The progression towards EA is estimated to affect 2 to 10% of BE patients, hence endoscopic surveillance of at-risk subjects is mandatory. Surveillance endoscopic procedures imply high cost, discomfort and risks for the patient, as well as the non-infrequent missing of small, focal lesions signaling progression to EA. Hence, it is important to search for new potential markers to better identify BE patients at risk of EA progression. The aim of this study was to produce a mouse model of BE, suitable for further molecular and genetic analyses. Methods: Forty-four CD1 mice were operated upon by means of an esophago-jejunal anastomosis. Five CD1 mice underwent a sham operation. The animals were sacrificed 10 months later and histological analysis was performed with Hematoxylin & Eosin and Alcian Blue staining. Results: The overall postoperative mortality rate was 11%. Of the 39 operated animals 14% developed histologically detectable intestinal metaplasia in the lower esophagus. No histologically detectable lesions were shown in the sham group. Conclusions: The mice model we propose could be applied because of its technical feasibility and acceptable mortality and can be used in transgenic mice too, in order to better understand molecular progression from BE to esophageal adenocarcinoma.

Introduction Among hindrances in cancer treatment, the lack of appropriate markers to be exploited for targeted therapy, and the need of new potential drugs are two big challenges.hERG1 potassium channels are a novel class of oncological targets and, in cancer, they are known to interact with integrins. It has been recently demonstrated that macromolecular complexes formed between hERG1 and β1 integrins selectively occurs in many types of cancer (Becchetti A et al., 2017). In this scenario, hERG1 could be exploited as a therapeutic target providing non cardiotoxic strategies aimed at blocking hERG1. Materials and Methods A scDb, a bifunctional single-chain diabody, directed against hERG1/β1 complex, was developed via SOE-PCR methodology. Such antibody was tested on HCT116 cells in lateral motility and western blotting experiments. Moreover immunohistochemistry (IHC) was performed on metastatic colorectal cancer (mCRC) paraffin embedded samples using the scDb, an anti-hERG1 and an anti-β1 integrin. Moreover, we improved the pro-apoptotic effects of the nude hERG1/β1-scDb, developing a trifunctional recombinant protein, in which the scDb-hERG1-β1 was linked to the tumour necrosis factor-related apoptosis-inducing ligand (TRAIL). Results and Discussion Performing IHC on sequential sections of mCRC confirmed the specificity of the scDb for both hERG1 and β1 integrin. In vitro data provide evidences that the administering of the bispecific antibody has an impact on lateral motility. Moreover, signaling pathways are also affected by the antibody treatment, as AKT phosphorylation and HIF1α levels are decreased when the molecule is administered, suggesting a possible effect of the bispecific antibody on the VEGF-A signaling pathway, which are consistent with our previous hypothesis (Becchetti A et al., 2017) of a possible cross-talk leading to a deep impact on VEGF expression and, thus, on neoangiogenesis. Encouraging results were obtained when testing the scDb-hERG1-β1 -TRAIL fusion protein, which was capable to produce a strong induction of apoptosis in ALL cells (32.6 vs 11% at 24h; 62.4% vs 10% at 48h), with no effects on TRAIL- resistant (Panc1) tumour cells. Conclusions scDb-hERG1/β1 could be used as a potential new therapeutic tool for cancer patients’ treatment as well as for early molecular diagnosis. In fact, the selective expression of hERG1/β1 complex in cancer cells and its role in angiogenesis and cancer progression suggests that a molecule selectively targeting the complex will be an invaluable tool for cancer treatment. In this view, we have recently licensed a patent which will be exploited with the final aim to undergo clinical trials. Becchetti A, et al. (2017) Science Signaling 10(473). Patent. Inventors: Arcangeli A, Duranti C. et al. Patent Ref: 102017000083637 Citation Format: Claudia Duranti, Jessica Iorio, Stefano Coppola, Giulia Petroni, Tiziano Lottini, Lara Magni, Elena Lastraioli, Annarosa Arcangeli. Novel strategies in cancer immunotherapy: Harness the hERG1 β1 macromolecular complex via a new bispecific antibody and its bifunctional TRAIL [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1216.

// Elena Lastraioli 1 , Tiziano Lottini 1 , Jessica Iorio 1 , Giancarlo Freschi 2 , Marilena Fazi 2 , Claudia Duranti 1 , Laura Carraresi 3 , Luca Messerini 1 , Antonio Taddei 2 , Maria Novella Ringressi 2 , Marianna Salemme 4 , Vincenzo Villanacci 4 , Carla Vindigni 5 , Anna Tomezzoli 6 , Roberta La Mendola 7 , Maria Bencivenga 7 , Bruno Compagnoni 8 , Mariella Chiudinelli 9 , Luca Saragoni 10 , Ilaria Manzi 11 , Giovanni De Manzoni 7 , Paolo Bechi 2 , Luca Boni 12, * , Annarosa Arcangeli 1, * 1 Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy 2 Department of Surgery and Translational Medicine, University of Florence, 50134 Florence, Italy 3 DI.V.A.L Toscana Srl, 50019 Sesto Fiorentino, Italy 4 Institute of Pathology, Spedali Civili, 25123 Brescia, Italy 5 Pathology Division, Azienda Ospedaliero-Universitaria Senese, 53100 Siena, Italy 6 Pathology Division, Borgo Trento Hospital, 37134 Verona, Italy 7 Division of Surgery, University of Verona, 37134 Verona, Italy 8 Surgery Division, Esine Hospital, ASL Vallecamonica Sebino, 25040 Esine (BS), Italy 9 Pathology Division, Esine Hospital, ASL Vallecamonica Sebino, 25040 Esine (BS), Italy 10 Pathology Division, Morgagni-Pierantoni Hospital, 47121 Forli, Italy 11 Gastroenterology and Endoscopy Unit, Morgagni-Pierantoni Hospital, 47121 Forli, Italy 12 Clinical Trials Coordinating Center, Azienda Ospedaliero-Universitaria Careggi/Istituto Toscano Tumori, 50134 Florence, Italy * These authors contributed equally to this work Correspondence to: Annarosa Arcangeli, email: annarosa.arcangeli@unifi.it Keywords: hERG1, Barrett’s esophagus, adenocarcinoma progression, surveillance, optical imaging Received: March 13, 2016 Accepted: July 09, 2016 Published: August 09, 2016 ABSTRACT Barrett’s esophagus (BE) is the only well-known precursor lesion of esophageal adenocarcinoma (EA). The exact estimates of the annual progression rate from BE to EA vary from 0.07% to 3.6%. The identification of BE patients at higher risk to progress to EA is hence mandatory, although difficult to accomplish. In search of novel BE biomarkers we analyzed the efficacy of hERG1 potassium channels in predicting BE progression to EA. Once tested by immunohistochemistry (IHC) on bioptic samples, hERG1 was expressed in BE, and its expression levels increased during progression from BE to esophageal dysplasia (ED) and EA. hERG1 was also over-expressed in the metaplastic cells arising in BE lesions obtained in different BE mouse models, induced either surgically or chemically. Furthermore, transgenic mice which over express hERG1 in the whole gastrointestinal tract, developed BE lesions after an esophago-jejunal anastomosis more frequently, compared to controls. A case-control study was performed on 104 bioptic samples from newly diagnosed BE patients further followed up for at least 10 years. It emerged a statistically significant association between hERG1 expression status and risk of progression to EA. Finally, a novel fluorophore- conjugated recombinant single chain variable fragment antibody (scFv-hERG1-Alexa488) was tested on freshly collected live BE biopsies: it could recognize hERG1 positive samples, perfectly matching IHC data. Overall, hERG1 can be considered a novel BE biomarker to be exploited for a novel endoscopic surveillance protocol, either in biopsies or through endoscopy, to identify those BE patients with higher risk to progress to EA.

BACKGROUND: There is a need to identify new markers to assess recurrence risk in early-stage colorectal cancer (CRC) patients. We explored the prognostic impact of ether-a-gò-gò-related gene 1 channels and some hypoxia markers, in patients with nonmetastatic (stage I, II, and III) CRC. METHODS: The expression of hERG1, vascular endothelial growth factor A (VEGF-A), glucose transporter 1, carbonic anhydrase IX (CA-IX), epidermal growth factor receptor (EGF-R), and p53 was tested by immunohistochemistry in 135 patients. The median follow-up was 35 months. Clinicopathologic parameters and overall survival were evaluated. RESULTS: hERG1 displayed a statistically significant association with Glut-1, VEGF-A, CA-IX, and EGF-R; p53 with VEGF-A and CA-IX; Glut-1 with the age of the patients; and EGF-R with TNM and mucin content. TNM and CA-IX were prognostic factors at the univariate analysis; TNM, hERG1, and Glut-1, at the multivariate analysis. Risk scores calculated from the final multivariate model allowed to stratify patients into four different risk groups: A) stage I-II, Glut-1 positivity, any hERG1; B) stage I-II, Glut-1 and hERG1 negativity; C) stage I-II, Glut-1 negativity, hERG1 positivity; D) stage III, any Glut-1 and any hERG1. CONCLUSIONS: hERG1 positivity with Glut-1 negativity identifies a patient group with poor prognosis within stage I-II CRC. The possibility that these patients might benefit from adjuvant therapy, independently from the TNM stage, is discussed. IMPACT: More robust prognostic and predictive markers, supplementing standard clinical and pathologic staging, are needed for node-negative patients.

Objective Endometrial cancer (EC) is the most frequent cancer of the female genital tract. It has been hypothesized that those ECs that occur in the postmenopausal period, might be sensitive to elevated levels of luteinizing hormone/human chorionic gonadotropin (LH/hCG). Based on previous indications, we analyzed the functional expression of LH/hCG receptors (LH/hCG-R) in primary ECs. Methods We studied a cohort of primary ECs, in which both the LH / hCG - R mRNA and the LH/hCG-R protein were analyzed. Results were correlated with both clinical–pathological data and the effects of LH addition on cell invasion in vitro . Results The LH / hCG - R mRNA levels ranged from 4.67 e −02 to 2.36 e +03 . The transcript was properly translated into a functional LH/hCG-R protein. The analysis of cell invasion in vitro in response to LH/hCG allowed us to divide the EC samples into two groups, one with a null or very low response (non-responders=NR) and the other with a significant response to LH (responders=R). The two groups had significantly different levels of LH / hCG - R mRNA expression: the NR group had a median value of 1.40 e + 00 , while the R group of 7.42 e + 01 ( p =0.043). Conclusion In primary ECs a statistically significant correlation emerged between the levels of LH / hCG - R mRNA and the LH-induced cell invasion in vitro . These results suggest that therapies aimed at decreasing LH levels, through Gonadotropin Releasing Hormone (Gn-RH) analogues, could produce benefits in the treatment of recurrent or metastatic EC, especially in patients displaying high LH/hCG-R levels.