Carbonic Anhydrase IV Research Articles

Carbonic anhydrase 2 mediates anti-obesity effects of black tea as thermogenic activator

Obesity is a metabolic disorder due to over-accumulation of adipose tissue and ultimately becomes a “disease”. Brown adipose tissue (BAT) thermogenesis and white adipose tissue (WAT) browning emerge as a potential strategy of anti-obesity by dissipating energy as heat. However, drugs based on adipose tissue thermogenesis have not been successfully approved yet. In current study, we found that black tea extract (BTE) obtained by patent-authorized manufacturing process prevented body weight gain as novel thermogenic activator with reduction of adiposity, improvement of adipose distribution, and glucose metabolism improvement in diet-induced obesity mice. Mechanismly, anti-obesity effect of BTE depends on promoting BAT thermogenesis and WAT browning with upregulation of uncoupling protein 1 (UCP1), especially visceral adipose tissue (VAT) with browning resistance. Specifically, utilizing in silico approach of network pharmacology and molecular docking, we identified carbonic anhydrase 2 (CA2) in nitrogen metabolism as anti-obesity target of BTE and further elucidated that protein kinase B (AKT) signaling pathway linked CA2 and UCP1. Meanwhile gut microbiota regulation may prompt the CA2-dependent thermogenesis activation. Our findings demonstrated anti-obesity effect of BTE as thermogenic activator through CA2-mediated BAT thermogenesis and WAT browning via CA2-AKT-UCP1 signaling pathway, which could be developed as promising anti-obesity agent with good safety and efficacy.

The role of GABA in modulation of taste signaling within the taste bud.

Taste buds contain 2 types of GABA-producing cells: sour-responsive Type III cells and glial-like Type I cells. The physiological role of GABA, released by Type III cells is not fully understood. Here, we investigated the role of GABA released from Type III cells using transgenic mice lacking the expression of GAD67 in taste bud cells (Gad67-cKO mice). Immunohistochemical experiments confirmed the absence of GAD67 in Type III cells of Gad67-cKO mice. Furthermore, no difference was observed in the expression and localization of cell type markers, ectonucleoside triphosphate diphosphohydrolase 2 (ENTPD2), gustducin, and carbonic anhydrase 4 (CA4) in taste buds between wild-type (WT) and Gad67-cKO mice. Short-term lick tests demonstrated that both WT and Gad67-cKO mice exhibited normal licking behaviors to each of the five basic tastants. Gustatory nerve recordings from the chorda tympani nerve demonstrated that both WT and Gad67-cKO mice similarly responded to five basic tastants when they were applied individually. However, gustatory nerve responses to sweet-sour mixtures were significantly smaller than the sum of responses to each tastant in WT mice but not in Gad67-cKO mice. In summary, elimination of GABA signalling by sour-responsive Type III taste cells eliminates the inhibitory cell-cell interactions seen with application of sour-sweet mixtures.

Ciliary Motility Decreased by a CO2/HCO3--Free Solution in Ciliated Human Nasal Epithelial Cells Having a pH Elevated by Carbonic Anhydrase IV.

An application of CO2/HCO3--free solution (Zero-CO2) did not increase intracellular pH (pHi) in ciliated human nasal epithelial cells (c-hNECs), leading to no increase in frequency (CBF) or amplitude (CBA) of the ciliary beating. This study demonstrated that the pHi of c-hNECs expressing carbonic anhydrase IV (CAIV) is high (7.64), while the pHi of ciliated human bronchial epithelial cells (c-hBECs) expressing no CAIV is low (7.10). An extremely high pHi of c-hNECs caused pHi, CBF and CBA to decrease upon Zero-CO2 application, while a low pHi of c-hBECs caused them to increase. An extremely high pHi was generated by a high rate of HCO3- influx via interactions between CAIV and Na+/HCO3- cotransport (NBC) in c-hNECs. An NBC inhibitor (S0859) decreased pHi, CBF and CBA and increased CBF and CBA in c-hNECs upon Zero-CO2 application. In conclusion, the interactions of CAIV and NBC maximize HCO3- influx to increase pHi in c-hNECs. This novel mechanism causes pHi to decrease, leading to no increase in CBF and CBA in c-hNECs upon Zero-CO2 application, and appears to play a crucial role in maintaining pHi, CBF and CBA in c-hNECs periodically exposed to air (0.04% CO2) with respiration.

Abstract Or121: Druggable Genome CRISPRi/a Screens in iPSC-Derived Cardiomyocytes Identify Therapeutic Targets for Doxorubicin-Induced Cardiotoxicity

Introduction: Doxorubicin is a highly effective chemotherapy drug whose therapeutic utility is significantly hampered by its life-threatening adverse cardiac effects. The need for strategies to mitigate these cardiotoxic effects without diminishing its efficacy against cancer is critical in cardio-oncology. Hypothesis: We hypothesize that through an integrated drug discovery pipeline, utilizing patient iPSC-derived cardiomyocytes (iCMs) and CRISPRi/a bidirectional pooled screens combined with small molecule screening and molecular docking, we can identify therapeutic targets that ameliorate doxorubicin-induced cardiotoxicity (DIC) while preserving its anticancer efficacy. Methods: Our approach included patient iPSC-derived cardiomyocytes (iCMs), CRISPRi/a bidirectional pooled screens targeting druggable genome (~2000 genes) to identify candidate genes implicated in DIC, and small molecule screening alongside molecular docking to find potential inhibitors. Notably, carbonic anhydrase 12 (CA12) was identified as a primary hit for its role in DIC. Results: The CRISPRi/a screens revealed several novel genes, including CA12, as potential contributors to DIC. Genetic inhibition of CA12 in iCMs enhanced cell survival, preserved sarcomere structure, and improved contractile function and calcium handling, effectively protecting against DIC. Furthermore, we discovered that a CA12 antagonist significantly attenuates DIC in both iCMs and mouse models. Mechanistic studies suggested that doxorubicin triggers CA12 activation, leading to a metabolic change towards glycolysis in cardiomyocytes, thereby exacerbating DIC by disrupting cellular metabolism and cardiac functions. Conclusions: Our findings propose a novel therapeutic avenue to safeguard against doxorubicin-induced cardiotoxicity through the targeting of CA12, offering new direction for the development of more refined anticancer therapies that minimize cardiotoxic risk. This study sets the stage of combining CRISPRi/a screen with iPSC technology for future drug discovery endeavors aimed at eliminating off-target cardiotoxicities of chemotherapy agents.

Assessment of the intensity of dental caries in patients with VDR and CA12 gene polymorphism

Assessment of the intensity of dental caries in patients with VDR and CA12 gene polymorphism

#102 Increased expression of carbonic anhydrase 4 in megalin deficiency

Abstract Background and Aims Megalin is an endocytic receptor located in the apical membrane of proximal tubule (PT) cells. It prevents low molecular-weight proteinuria by reuptake of a variety of proteins from the filtrate. Megalin is required for normal uptake of Cubilin-bound proteins, but it is unknown if the receptor is important for other apical PT proteins. Carbonic anhydrase 4 (CA4) is an enzyme crucial for PT bicarbonate reuptake. Our aim was to investigate the relationship between the expression patterns of these two proteins. Method A mouse model of kidney-specific mosaic megalin-knockout (M-KO). Liquid chromatography-mass spectrometry (LC-MS) on mouse kidney cortex. Immunohistochemistry (IHC), electron microscopy (EM) and Western blotting (WB) of mouse kidney. Biochemical analysis of mouse blood and urine. Results LC-MS revealed a 4.23-fold increase in CA4 abundance in M-KO mice together with smaller but also statistically significant alterations in other acid-base-associated proteins. IHC shows that the increase in CA4 abundance specifically was in the cells lacking megalin, while cells with megalin retained normal abundance. The same pattern was observed in a biopsy from a patient lacking megalin. WB revealed increased shedding of CA4 in urine from M-KO mice and EM showed mislocalization of CA4. Conclusion We show a hitherto unknown relationship where the expression and subcellular localization of CA4 is altered in PT-cells lacking megalin and show that M-KO mice have altered acid-base handling. Comparable blood parameters at baseline are maintained despite differences in urinary excretion and when challenged with acetazolamide the urinary excretion of the groups becomes alike, however blood parameters become different. While the mechanisms and full extend are unknown, this links megalin to the acid-base regulating systems of the PT.

Abstract LB072: Tumor-infiltrating lymphocytes (TIL) engineered with membrane-bound IL15 (cytoTIL15 cells) exhibit pharmacologically regulatable signal transduction in cis and trans

Abstract Introduction: We have previously shown the successful engineering of membrane-bound IL15 (mbIL15)-expressing tumor-infiltrating lymphocytes (TIL; cytoTIL15™ cells) from solid tumors such as melanoma, which are CD8+ enriched TIL exhibiting enhanced persistence and anti-tumor activity compared with unengineered TIL (SITC 2022, 2023; clinical candidate OBX-115: NCT05470283). The mbIL15 expressed by cytoTIL15 cells is regulated via a carbonic anhydrase 2 (CA2) drug-responsive domain, which allows expression to be induced upon delivery of the FDA-approved small molecule ligand acetazolamide (ACZ) and was designed to engage the IL2Rβ and IL2Rγ receptors in both cis and in trans. Using natural killer (NK) cells, which are potently responsive to soluble, trans-presented IL15, as an experimental model system, we examined the potential of mbIL15 on cytoTIL15 cells to potentiate activity in both cis and trans. Methods: cytoTIL15 cells and unengineered TIL were generated as described previously (SITC 2022, 2023). Cells were assessed for expression of mbIL15 and phosphorylation of downstream signaling molecules STAT5 and S6 by flow cytometry, and co-cultured with allogeneic healthy donor NK cells for 1-10 days with and without transwell inserts. Functional effects of cytoTIL15 cells were compared to those of soluble recombinant IL15. Supernatant was obtained from co-cultures for assessment of cytokine production. Results: cytoTIL15 cells demonstrated robust ACZ-dependent mbIL15 expression, and ACZ dosing regulated mbIL15 activity in cis by potentiating the phosphorylation of STAT5 (geoMFI with 0 vs. 25 µM ACZ, p=0.012) and S6 (geoMFI with 0 vs. 25 µM ACZ, p=0.016). Upon removal of ACZ, mbIL15 expression and pSTAT5 and pS6 returned to basal levels within 24 hours. mbIL15 expressed on the surface of cytoTIL15 cells could also activate cells in trans in an ACZ-dependent titratable manner. Specifically, co-culture of cytoTIL15 cells with NK cells led to an ACZ-dependent increase in pSTAT5 (geoMFI with 0 vs. 25 µM ACZ, p=0.038) in NK cells, which was not seen in co-cultures of unengineered TIL with NK cells. Additionally, NK cells showed a similar cytokine production profile when exposed to mbIL15 by cytoTIL15 cells as with soluble, trans-presented IL15. NK cell transactivation relied on direct cell contact with cytoTIL15 cells, as magnitudes of phosphorylation were decreased in co-cultures with NK and cytoTIL15 cells separated by a transwell membrane (pSTAT5 geoMFI p=0.008). Conclusions: cytoTIL15 cells demonstrate functional engagement of cytokine receptors via mbIL15 in both cis and in trans, including phosphorylation of STAT5 and S6. Taken together, these data highlight the potential for robust activity of cytoTIL15 cells through potentiation of ACZ-dependent mbIL15 activity in both cis and trans. Citation Format: Rachel Burga, Gauri Kulkarni, Zheng Ao, Dhruv K. Sethi, Jan ter Meulen, Michelle Ols. Tumor-infiltrating lymphocytes (TIL) engineered with membrane-bound IL15 (cytoTIL15 cells) exhibit pharmacologically regulatable signal transduction in cis and trans [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB072.

Auranofin repurposing for lung and pancreatic cancer: low CA12 expression as a marker of sensitivity in patient-derived organoids, with potentiated efficacy by AKT inhibition

BackgroundThis study explores the repurposing of Auranofin (AF), an anti-rheumatic drug, for treating non-small cell lung cancer (NSCLC) adenocarcinoma and pancreatic ductal adenocarcinoma (PDAC). Drug repurposing in oncology offers a cost-effective and time-efficient approach to developing new cancer therapies. Our research focuses on evaluating AF's selective cytotoxicity against cancer cells, identifying RNAseq-based biomarkers to predict AF response, and finding the most effective co-therapeutic agents for combination with AF.MethodsOur investigation employed a comprehensive drug screening of AF in combination with eleven anticancer agents in cancerous PDAC and NSCLC patient-derived organoids (n = 7), and non-cancerous pulmonary organoids (n = 2). Additionally, we conducted RNA sequencing to identify potential biomarkers for AF sensitivity and experimented with various drug combinations to optimize AF's therapeutic efficacy.ResultsThe results revealed that AF demonstrates a preferential cytotoxic effect on NSCLC and PDAC cancer cells at clinically relevant concentrations below 1 µM, sparing normal epithelial cells. We identified Carbonic Anhydrase 12 (CA12) as a significant RNAseq-based biomarker, closely associated with the NF-κB survival signaling pathway, which is crucial in cancer cell response to oxidative stress. Our findings suggest that cancer cells with low CA12 expression are more susceptible to AF treatment. Furthermore, the combination of AF with the AKT inhibitor MK2206 was found to be particularly effective, exhibiting potent and selective cytotoxic synergy, especially in tumor organoid models classified as intermediate responders to AF, without adverse effects on healthy organoids.ConclusionOur research offers valuable insights into the use of AF for treating NSCLC and PDAC. It highlights AF's cancer cell selectivity, establishes CA12 as a predictive biomarker for AF sensitivity, and underscores the enhanced efficacy of AF when combined with MK2206 and other therapeutics. These findings pave the way for further exploration of AF in cancer treatment, particularly in identifying patient populations most likely to benefit from its use and in optimizing combination therapies for improved patient outcomes.

Hedgehog Pathway Inhibition by Novel Small Molecules Impairs Melanoma Cell Migration and Invasion under Hypoxia.

Melanoma is the principal cause of death in skin cancer due to its ability to invade and cause metastasis. Hypoxia, which characterises the tumour microenvironment (TME), plays an important role in melanoma development, as cancer cells can adapt and acquire a more aggressive phenotype. Carbonic anhydrases (CA) activity, involved in pH regulation, is related to melanoma cell migration and invasion. Furthermore, the Hedgehog (Hh) pathway, already known for its role in physiological processes, is a pivotal character in cancer cell growth and can represent a promising pharmacological target. In this study, we targeted Hh pathway components with cyclopamine, glabrescione B and C22 in order to observe their effect on carbonic anhydrase XII (CAXII) expression especially under hypoxia. We then performed a migration and invasion assay on two melanoma cell lines (SK-MEL-28 and A375) where Smoothened, the upstream protein involved in Hh regulation, and GLI1, the main transcription factor that determines Hh pathway activation, were chemically inhibited. Data suggest the existence of a relationship between CAXII, hypoxia and the Hedgehog pathway demonstrating that the chemical inhibition of the Hh pathway and CAXII reduction resulted in melanoma migration and invasion impairment especially under hypoxia. As in recent years drug resistance to small molecules has arisen, the development of new chemical compounds is crucial. The multitarget Hh inhibitor C22 proved to be effective without signs of cytotoxicity and, for this reason, it can represent a promising compound for future studies, with the aim to reach a better melanoma disease management.

Carbonic Anhydrase 4 Serves as A Novel Prognostic Biomarker and Therapeutic Target for Non-Small Cell Lung Cancer: A Study Based on TCGA Samples.

Carbonic anhydrase 4 (CA4) is a member of a large family of zinc metalloenzymes that catalyze the reversible hydration of carbon dioxide and was found to have low expression in non-small cell lung cancer (NSCLC). However, the specific role of CA4 in NSCLC and the underlying mechanisms remain unknown. The bioinformatic analysis on lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) datasets downloaded from The Cancer Genome Atlas (TCGA) database was performed. We found that CA4 expression was lower in tumors than that in normal tissues, which were verified by Real-time PCR. Lower CA4 levels were significantly associated with higher T stages in LUAD and LUSC cohorts. Multivariate analysis showed that CA4 is an independent prognostic factor for NSCLC. Furthermore, the expression of CA4 also correlated with immune infiltration and drug sensitivity. Ectopic expression of CA4 decreased NSCLC cell proliferation in vitro by CCK-8 assay. CA4 caused G0/G1 cell cycle arrest by cell experiments. Mechanistic studies found that CA affects the cell cycle and inhibits cell proliferation by downregulating the expression of CDK2. The present findings highlight the role of CA4 in NSCLC and identify CA4 as a potential novel diagnostic and prognostic biomarker for the treatment of NSCLC.

Machine-Learning-Based Data Analysis Method for Cell-Based Selection of DNA-Encoded Libraries.

DNA-encoded library (DEL) is a powerful ligand discovery technology that has been widely adopted in the pharmaceutical industry. DEL selections are typically performed with a purified protein target immobilized on a matrix or in solution phase. Recently, DELs have also been used to interrogate the targets in the complex biological environment, such as membrane proteins on live cells. However, due to the complex landscape of the cell surface, the selection inevitably involves significant nonspecific interactions, and the selection data are much noisier than the ones with purified proteins, making reliable hit identification highly challenging. Researchers have developed several approaches to denoise DEL datasets, but it remains unclear whether they are suitable for cell-based DEL selections. Here, we report the proof-of-principle of a new machine-learning (ML)-based approach to process cell-based DEL selection datasets by using a Maximum A Posteriori (MAP) estimation loss function, a probabilistic framework that can account for and quantify uncertainties of noisy data. We applied the approach to a DEL selection dataset, where a library of 7,721,415 compounds was selected against a purified carbonic anhydrase 2 (CA-2) and a cell line expressing the membrane protein carbonic anhydrase 12 (CA-12). The extended-connectivity fingerprint (ECFP)-based regression model using the MAP loss function was able to identify true binders and also reliable structure-activity relationship (SAR) from the noisy cell-based selection datasets. In addition, the regularized enrichment metric (known as MAP enrichment) could also be calculated directly without involving the specific machine-learning model, effectively suppressing low-confidence outliers and enhancing the signal-to-noise ratio. Future applications of this method will focus on de novo ligand discovery from cell-based DEL selections.

Asymmetric expression of CA2 and CA13 linked to calcification in the bilateral mandibular condyles cause crossed beaks in chickens

Crossed beak is a complex mode of inheritance with prevalence ranging from 0.2 to 7.4% in at least 12 chicken strains worldwide. To reveal the intrinsic factors causing crossed beaks, genes expression patterns in bilateral mandibular condyle between affected and normal birds were characterized by RNA sequencing analysis in the present studies. Crossed beak was induced by short length of unilateral mandibular ramus, and a total of 110 differentially expressed genes were up- or down-regulated in the affected (short) mandibular condyle side as compared to the normal side. Carbonic anhydrase 2 (CA2) and Carbonic anhydrase 13 (CA13) were enriched in the carbonate dehydratase activity, and high-expressed in mandibular condyle and osteoblasts (P<0.05). However, both were low-expressed in short mandibular condyle side of affected birds (P<0.05). The carbonate dehydratase inhibitor experiments confirmed that there is positive association between the calcification and carbonic anhydrase isoenzymes. Quantitative analysis with cetylpyridinium chloride showed a decrease in calcification when the cells were transfected with an anti-CA13 shRNA. Our research suggested that CA2 and CA13 are down-calcified in short-side mandibular condyle, and caused mandibular ramus to grow slowly. CA2 and CA13 have the critical role in crossed beaks by regulating calcification of mandibular condyle.

Aging-associated increased nitric oxide production is a potential cause of inferior eggshell quality produced by aged laying hens

It is important to prolong the productive life of laying hens without compromising their welfare. Therefore, in this study, we aimed to identify the cause for inferior quality egg production of aged hens by investigating the aging-associated molecular changes related to eggshell formation in the isthmic and uterine mucosae and determining whether nitric oxide plays a role in decreasing the quality of eggs produced by aged hens. Young (35 weeks old) and aged (130 weeks old) White Leghorn laying hens were used in this study to determine the effects of age on the expression of proteins related to eggshell membranes formation in the isthmus and eggshell biomineralization and nitric oxide production in the uterus. Nitric oxide synthesis during the ovulatory cycle was examined in twenty-five laying hens (46–52 weeks old) euthanized at 0, 4, 7, 16, and 24 h after oviposition. S-Nitroso-N-acetylpenicillamine (a nitric oxide donor) was added to the cultured isthmic and uterine mucosal cells to examine the effects of nitric oxide on the expression of genes related to eggshell membranes formation and eggshell biomineralization, respectively. The results showed that the protein abundance of collagen I and V in the isthmic mucosa and collagen V in the eggshell membranes were lower in aged hens than in young hens. The mRNA expression levels of calbindin, osteopontin, and ovocalyxin-36 and the protein abundance of calbindin and carbonic anhydrase-2 were lower in the uterine mucosa of aged hens than in that of young hens. Nitric oxide synthesis was higher in the uterine mucosa of aged hens than in that of young hens. Nitric oxide downregulated the mRNA expression levels of osteopontin and ovocalyxin-36 in cultured uterine mucosal cells. Our results indicated that the eggshell quality decreases with aging due to molecular changes in the uterine mucosa affecting the eggshell membrane formation and eggshell biomineralization. Moreover, nitric oxide overproduction may play a role in this dysfunction.

In-depth proteomic signature of parathyroid carcinoma.

Diagnosing parathyroid carcinoma (PC) is complicated and controversial that early diagnosis and intervention are often difficult. Therefore, we aimed to elucidate the protein signatures of PC through quantitative proteomic analyses to aid in the early and accurate diagnosis of PC. We conducted a retrospective cohort study. We performed liquid chromatography with tandem mass spectrometry using formalin-fixed paraffin-embedded samples. For the analyses, 23 PC and 15 parathyroid adenoma (PA) tissues were collected from 6 tertiary hospitals in South Korea. The mean age of the patients was 52 years, and 63% were women. Proteomic expression profiling revealed 304 differentially expressed proteins (DEPs) with a cut-off of P < .05 and fold change >1.5. Among DEPs, we identified a set of 5 proteins that can discriminate PC from PA: carbonic anhydrase 4 (CA4), alpha/beta hydrolase domain-containing protein 14B (ABHD14B), laminin subunit beta-2 (LAMB2), CD44 antigen (CD44), and alpha-1-acid glycoprotein 1 (ORM1) that exhibited the highest area under the curve of 0.991 in neural network model. The nuclear percentage of CA4 and LAMB2 in immunohistochemistry was significantly lower in PC tissue than in the PA (CA4: 2.77 ± 1.96%, 26.2 ± 3.45%, P < .001; LAMB2: 6.86 ± 3.46%, 38.54 ± 4.13%, P < .001). The most enriched canonical pathways in PC included glycoprotein-6 signaling and mammalian target of rapamycin (mTOR). We identified key proteins differentially expressed between PC and PA using proteomic analyses of parathyroid neoplasms. These findings may help to diagnose PC accurately and elucidate potential therapeutic targets.

Indisulam Reduces Viability and Regulates Apoptotic Gene Expression in Pediatric High-Grade Glioma Cells.

Pediatric high-grade glioma (pHGG) is one of the most aggressive brain tumors. Treatment includes surgery, radiotherapy, chemotherapy, or combination therapy in children older than 3-5 years of age. These devastating tumors are influenced by the hypoxic microenvironment that coordinatively increases the expression of carbonic anhydrases (CA9 and CA12) that are involved in pH regulation, metabolism, cell invasion, and resistance to therapy. The synthetic sulphonamide Indisulam is a potent inhibitor of CAs. The aim of this study was to evaluate the effects of Indisulam on CA9 and CA12 enzymes in pHGG cell lines. Our results indicated that, under hypoxia, the gene and protein expression of CA9 and CA12 are increased in pHGG cells. The functional effects of Indisulam on cell proliferation, clonogenic capacity, and apoptosis were measured in vitro. CA9 and CA12 gene and protein expression were analyzed by RT-PCR and western blot. The treatment with Indisulam significantly reduced cell proliferation (dose-time-dependent) and clonogenic capacity (p &lt; 0.05) and potentiated the effect of apoptosis (p &lt; 0.01). Indisulam promoted an imbalance in the anti-apoptotic BCL2 and pro-apoptotic BAX protein expression. Our results demonstrate that Indisulam contributes to apoptosis via imbalance of apoptotic proteins (BAX/BCL2) and suggests a potential to overcome chemotherapy resistance caused by the regulation these proteins.

Lyve-1 deficiency enhances the hepatic immune microenvironment entailing altered susceptibility to melanoma liver metastasis.

Hyaluronan receptor LYVE-1 is expressed by liver sinusoidal endothelial cells (LSEC), lymphatic endothelial cells and specialized macrophages. Besides binding to hyaluronan, LYVE-1 can mediate adhesion of leukocytes and cancer cells to endothelial cells. Here, we assessed the impact of LYVE-1 on physiological liver functions and metastasis. Mice with deficiency of Lyve-1 (Lyve-1-KO) were analyzed using histology, immunofluorescence, microarray analysis, plasma proteomics and flow cytometry. Liver metastasis was studied by intrasplenic/intravenous injection of melanoma (B16F10 luc2, WT31) or colorectal carcinoma (MC38). Hepatic architecture, liver size, endothelial differentiation and angiocrine functions were unaltered in Lyve-1-KO. Hyaluronan plasma levels were significantly increased in Lyve-1-KO. Besides, plasma proteomics revealed increased carbonic anhydrase-2 and decreased FXIIIA. Furthermore, gene expression analysis of LSEC indicated regulation of immunological pathways. Therefore, liver metastasis of highly and weakly immunogenic tumors, i.e. melanoma and colorectal carcinoma (CRC), was analyzed. Hepatic metastasis of B16F10luc2and WT31 melanoma cells, but not MC38 CRC cells, was significantly reduced inLyve-1-KO mice. In vivo retention assays with B16F10luc2cells were unaltered between Lyve-1-KO and control mice. However, in tumor-free Lyve-1-KO livers numbers of hepatic CD4+, CD8+ and regulatory Tcells were increased. In addition, iron deposition was found in F4/80+ liver macrophages known to exert pro-inflammatory effects. Lyve-1 deficiency controlled hepatic metastasis in a tumor cell-specific manner leading to reduced growth of hepatic metastases of melanoma, but not CRC. Anti-tumorigenic effects are likely due to enhancement of the premetastatic hepatic immune microenvironment influencing early liver metastasis formation.

Carbonic anhydrase 4 disruption decreases synaptic and behavioral adaptations induced by cocaine withdrawal.

Cocaine use followed by withdrawal induces synaptic changes in nucleus accumbens (NAc), which are thought to underlie subsequent drug-seeking behaviors and relapse. Previous studies suggest that cocaine-induced synaptic changes depend on acid-sensing ion channels (ASICs). Here, we investigated potential involvement of carbonic anhydrase 4 (CA4), an extracellular pH-buffering enzyme. We examined effects of CA4 in mice on ASIC-mediated synaptic transmission in medium spiny neurons (MSNs) in NAc, as well as on cocaine-induced synaptic changes and behavior. We found that CA4 is expressed in the NAc and present in synaptosomes. Disrupting CA4 either globally, or locally, increased ASIC-mediated synaptic currents in NAc MSNs and protected against cocaine withdrawal-induced changes in synapses and cocaine-seeking behavior. These findings raise the possibility that CA4 might be a previously unidentified therapeutic target for addiction and relapse.

CAXII Is a Surrogate Marker for Luminal Breast Tumors Regulated by ER and GATA3.

Estrogen receptor alpha (ERα) expression in ~2/3 breast tumors selects patients for hormonal therapies. Tumors negative for ERα but positive for the progesterone receptor (PR, encoded by PGR) have also been candidates for ER-targeting therapies, as PR expression may reflect undetected ER activity. Conversely, PR- status in ER+ tumors predicts a worse therapeutic response. Our analysis of breast tumor transcriptome datasets, however, revealed that in tumors with lower PGR expression, the clinical PR status does not correlate accurately with the expression of ESR1 or of ER target genes, including PGR itself. We identified carbonic anhydrase 12 (CA12) as an estrogen target gene better correlated with ESR1 than PGR, reflecting CA12 regulation by both ERα and the luminal factor and upstream ESR1 regulator GATA3. Immunostaining supported strong positive correlations at the protein level with ERα and GATA3 in a cohort of 118 tumors. Most ER+PR- tumors expressed CAXII at levels similar to those of ER+PR+ tumors, consistent with observations in tumor transcriptome datasets and with active estrogenic signaling in some ER+PR- breast cancer cell lines. The few ER-PR+ tumors did not express CAXII or the other luminal markers FOXA1 and GATA3. Overall, CAXII is a luminal marker that can help interpret ER status in single ER/PR positive tumors.

381 Carbonic anhydrase12 knockout mimics cystic fibrosis cellular phenotypes

381 Carbonic anhydrase12 knockout mimics cystic fibrosis cellular phenotypes

Role of the Hedgehog Pathway and CAXII in Controlling Melanoma Cell Migration and Invasion in Hypoxia.

Simple SummaryMalignant melanoma is the leading cause of death among skin cancer patients due to its tendency to metastasize. Hypoxia, which is a common feature of the tumor microenvironment, as well as different alterations at the molecular level, may affect melanoma aggressiveness. The aims and the objectives of this work were to investigate whether and how the Hedgehog pathway and CAXII may control malignant melanoma cell migration and invasiveness either in normoxic or hypoxic conditions. To this end we evaluated the migratory and invasive capabilities of SK-MEL-28 and A375 cell lines, where the hedgehog pathways and CAXII were inhibited by short interfering RNA. Our results indicate that SMO and GLI1 silencing caused the downregulation of CAXII expression. Furthermore, the Hedgehog pathway and CAXII inhibition, resulted in impaired melanoma cell migration and invasion either under normoxic or hypoxic conditions. The fact that CAXII and the Hedgehog pathway are relevant in melanoma cell invasion may be exploited to discover novel and promising therapeutical targets for melanoma clinical management.Background: Malignant melanoma is the leading cause of death among skin cancer patients due to its tendency to metastasize. Alterations at the molecular level are often evident, which is why melanoma biology has garnered increasing interest. The hedgehog (Hh) pathway, which is essential for embryonic development, is aberrantly re-activated in melanoma and may represent a promising therapeutic target. In addition, carbonic anhydrase XII (CAXII) represents a poor prognostic target for hypoxic tumors, such as melanoma, and is involved in cell migration. Thus, we decided to investigate whether and how the Hh pathway and CAXII may control melanoma cell migration and invasiveness. Methods: The migratory and invasive capabilities of SK-MEL-28 and A375 cell lines, either un-transfected or transiently transfected with Smoothened (SMO), GLI1, or CAXII siRNA, were studied under normoxic or hypoxic conditions. Results: For the first time, we showed that SMO and GLI1 silencing resulted in the downregulation of CAXII expression in both moderately and highly invasive melanoma cells under hypoxia. The Hh pathway as well as CAXII inhibition by siRNA resulted in impaired malignant melanoma migration and invasion. Conclusion: Our results suggest that CAXII and the Hh pathway are relevant in melanoma invasion and may be novel and promising therapeutical targets for melanoma clinical management.