Carbonic anhydrase-related protein VIII promotes colon cancer cell growth

Effects of down-regulated carbonic anhydrase 8 on cell survival and glucose metabolism in human colorectal cancer cell lines

Carbonic anhydrase 8 (CA8) is a member of the α-carbonic anhydrase family but does not catalyze the reversible hydration of carbon dioxide. In the present study, we examined the effects of CA8 on two human colon cancer cell lines, SW480 and SW620, by suppressing CA8 expression through shRNA knockdown. Our results showed that knockdown of CA8 decreased cell growth and cell mobility in SW620 cells, but not in SW480 cells. In addition, downregulated CA8 resulted in a significant decrease of glucose uptake in both SW480 and SW620 cells. Interestingly, stable downregulation of CA8 decreased phosphofructokinase-1 expression but increased glucose transporter 3 (GLUT3) levels in SW620 cells. However, transient downregulation of CA8 fails to up-regulate GLUT3 expression, indicating that the increased GLUT3 observed in SW620-shCA8 cells is a compensatory effect. In addition, the interaction between CA8 and GLUT3 was evidenced by pull-down and IP assays. On the other hand, we showed that metformin, a first-line drug for type II diabetes patients, significantly inhibited cell migration of SW620 cells, depending on the expressions of CA8 and focal adhesion kinase. Taken together, our data demonstrate that when compared to primary colon cancer SW480 cells, metastatic colon cancer SW620 cells respond differently to downregulated CA8, indicating that CA8 in more aggressive cancer cells may play a more important role in controlling cell survival and metformin response. CA8 may affect glucose metabolism- and cell invasion-related molecules in colon cancer, suggesting that CA8 may be a potential target in future cancer therapy.

Carbonic Anhydrase VIII (CAVIII) Gene Mediated Colorectal Cancer Growth and Angiogenesis through Mediated miRNA 16-5p

Carbonic anhydrase VIII (CAVIII) is a member of the CA family, while CA8 is the oncogene. Here we observed increased expression of CAVIII with high expression in colorectal cancer tissues. CAVIII is also expressed in more aggressive types of human colorectal cancer cells. Upregulated CAVIII expression in SW480 cell lines increased vascular endothelial growth factor (VEGF) and reduced miRNA16-5p. Conversely, knockdown of the CAVIII results in VEGF decline by up-regulated miRNA16-5p. Moreover, the collection of different grades of CAVIII expression CRC cells supernatant co-culture with endothelial progenitor cells (EPCs) promotes the ability of tube formation in soft agar and migration in the Transwell experiment, indicating that CAVIII might facilitate cancer-cell-released VEGF via the inhibition of miRNA16-5p signaling. Furthermore, in the xenograft tumor angiogenesis model, knockdown of CAVIII significantly reduced tumor growth and tumor-associated angiogenesis. Taken together, our results prove that the CAVIII/miR-16-5p signaling pathway might function as a metastasis suppressor in CRC. Targeting CAVIII/miR-16-5p may provide a strategy for blocking its metastasis.

Development and validation of a four-lipid metabolism gene signature for diagnosis of pancreatic cancer

Abnormal lipid metabolism is closely related to the malignant biological behavior of tumor cells. Such abnormal lipid metabolism provides energy for rapid proliferation, and certain genes related to lipid metabolism encode important components of tumor signaling pathways. In this study, we analyzed pancreatic cancer datasets from The Cancer Genome Atlas and searched for prognostic genes related to lipid metabolism in the Molecular Signature Database. A risk score model was built and verified using the GSE57495 dataset and International Cancer Genome Consortium dataset. Four molecular subtypes and 4249 differentially expressed genes (DEGs) were identified. The DEGs obtained by Weighted Gene Coexpression Network Construction analysis were intersected with 4249 DEGs to obtain a total of 1340 DEGs. The final prognosis model included CA8, CEP55, GNB3 and SGSM2, and these had a significant effect on overall survival. The area under the curve at 1, 3 and 5 years was 0.72, 0.79 and 0.87, respectively. These same results were obtained using the validation cohort. Survival analysis data showed that the model could stratify the prognosis of patients with different clinical characteristics, and the model has clinical independence. Functional analysis indicated that the model is associated with multiple cancer-related pathways. Compared with published models, our model has a higher C-index and greater risk value. In summary, this four-gene signature is an independent risk factor for pancreatic cancer survival and may be an effective prognostic indicator.

Expression and Functional Study of Single Mutations of Carbonic Anhydrase 8 in Neuronal Cells

Carbonic anhydrase 8 (CA8), an isozyme of α-carbonic anhydrases, lacks the ability to catalyze the reversible hydration of CO₂ to bicarbonate and proton. Previous studies have shown that single point mutations of CA8, CA8-S100P, and CA8-G162R, are associated with novel syndromes including congenital ataxia and mild cognitive impairment. Our previous results demonstrated that overexpression of wild type (WT) CA8 promoted cell proliferation, neurite outgrowth, anti-apoptosis, invasion and migration abilities in neuronal cells. In this study, we examined the expressions and functions of CA8-S100P and CA8-G162R in neuroblastoma cells lines, compared with those of WT CA8. Our results show that the protein expressions of mutant CA8-S100P and CA8-G162R were significantly decreased in Neuro-2a and SK-N-SH cells. Interestingly, CA8-S100P demonstrated a significant increase in cell proliferation in both Neuro-2a and SK-N-SH cells. However, both CA8 mutations showed significantly decreased effects on cell protection and migration in SK-N-SH cells. Surprisingly, a significant increase of invasive ability was observed in SK-N-SH cells with overexpression of CA8-S100P as compared with those with overexpression of WT CA8 under retinoic acid (RA) treatment. In addition, we found that Neuro-2a cells with overexpression of CA8-S100P and CA8-G162R showed significantly increased neurite outgrowth. Taken together, our data suggest that the expressions of CA8-S100P and CA8-G162R in neuronal cells alter cell morphology, proliferation, mobility and viability; indicating that the homozygous point mutations of CA8 lead to not only the loss of WT CA8 function, but also the gain of novel functions leading to neuromuscular dysfunction.

CA8 promotes RCC proliferation and migration though its expression level is lower in tumor compared to adjacent normal tissue

Chemotherapy and radiotherapy are not as successful in the case of renal cell carcinoma (RCC) although some targeted drugs were approved for RCC therapy recently. Analysis of whole genomic data will lead to improvements in understanding RCC and identifying novel anticancer targets. Here, we found the differential mRNA expression and copy number variation (CNV) of Carbonic anhydrase-related protein VIII (CA8) gene in RCC through integrated bioinformatics analysis of TCGA database, which was confirmed in 5 cases of samples collected from RCC patients who underwent radical nephrectomy by analysis of CA8 mRNA and protein levels using RT-PCR immunohistochemical assay. However, we got a completely opposite result that CA8 promoted RCC progression, those are CA8 overexpression promoted the proliferative and migratory ability of Caki-1 and 769-P cells in vitro as determined with MTT and transwell assay, and CA8 overexpression could also promote Caki-1 xenograft growth in BALB/C‑nu/nu mice. On the contrary, CA8-knockdown reduced Caki-1 and 769-P cell proliferation and migration. Moreover, knockdown of CA8 decreased pAKT and MMP2 protein levels in Caki-1 cells while overexpressing CA8 increased pAKT and MMP2. In conclusion, we showed that CA8 promoted RCC cell proliferation and migration, but it was down-regulated in RCC, which requires an additional mechanism study.

Carbonic anhydrases as disease markers

INTRODUCTION

The physiologic importance of fast CO₂/HCO₃^- interconversion in various tissues requires the presence of carbonic anhydrase (CA, EC 4.2.1.1). Fourteen CA isozymes are present in humans, all of them being used as biomarkers.

AREAS COVERED

A great number of patents and articles were focused on the use of CA isozymes as biomarkers for various diseases and syndromes in the recent years, in an ascending trend over the last decade. The review highlights the most important studies related with each isozyme and covers the most recent patent literature.

EXPERT OPINION

The CAs biomarker research area expanded significantly in recent years, shifting from the predominant use of CA IX and CA XII in cancer diagnostic, staging, and prognosis towards a wider use of CA isozymes as disease biomarkers. CA isozymes are currently used either alone, in tandem with other CA isozymes and/or in combination with other proteins for the detection, staging, and prognosis of a huge repertoire of human dysfunctions and diseases, ranging from mild transformation of the normal tissues to extreme shifts in tissue organization and function. The techniques used for their detection/quantitation and the state-of-the-art in each clinical application are presented through relevant clinical examples and corresponding statistical data.

CA10 and CA11 negatively regulate neuronal activity-dependent growth of gliomas

Recent studies have revealed that neurons can promote glioma growth through activity‐dependent secretion of neurotrophins, especially neuroligin‐3. It has therefore been suggested that blocking neuron‐derived neurotrophins may serve as a therapeutic intervention for gliomas. Carbonic anhydrase‐related proteins 11 and 10 (CA11 and CA10) are secreted synaptic proteins which function as neurexin ligands, and the gene‐encoding CA11 is part of a gene signature associated with radiotherapy and prognosis in gliomas. We therefore hypothesized that CA11/CA10 might participate in the neuronal activity‐dependent regulation of glioma growth. In this study, we report that CA11 secreted by depolarized cultured neurons within conditioned medium (CM) inhibited the growth of glioma cell lines. CM from depolarized neurons inhibited CA11 expression in glioma cell lines via the Akt signaling pathway. Consistently, CA11 expression was also reduced in clinical glioma samples and negatively associated with high histological grade. Low CA11 expression of gliomas was associated with short survival in four independent datasets [repository of brain neoplasia data (REMBRANDT), The Cancer Genome Atlas (TCGA) lower grade glioma (LGG), GSE4271, and GSE42669]. CA11 knockdown promoted cell growth, clone formation, and migration; inhibited apoptosis; and increased tumor size in xenografted nude mice. Similarly, CA10 and CA10 secreted by depolarized cultured neurons also inhibited the growth of glioma cell lines. Low CA10 expression was associated with short survival in REMBRANDT, TCGA LGG, and GEO GSE4271 datasets. Our results suggest that CA11 and CA10 negatively regulate neuronal activity‐dependent glioma growth and inhibit glioma aggression. Thus, CA11/CA10 may represent a potential therapeutic target for the treatment of gliomas.

Carbonic anhydrase related protein expression in astrocytomas and oligodendroglial tumors

Background

Carbonic anhydrase related proteins (CARPs) VIII, X and XI functionally differ from the other carbonic anhydrase (CA) enzymes. Structurally, they lack the zinc binding residues, which are important for enzyme activity of classical CAs.

The distribution pattern of the CARPs in fetal brain implies their role in brain development. In the adult brain, CARPs are mainly expressed in the neuron bodies but only weaker reactivity has been found in the astrocytes and oligodendrocytes. Altered expression patterns of CARPs VIII and XI have been linked to cancers outside the central nervous system.

There are no reports on CARPs in human astrocytomas or oligodendroglial tumors. We wanted to assess the expression of CARPs VIII and XI in these tumors and study their association to different clinicopathological features and tumor-associated CAs II, IX and XII.

Methods

The tumor material for this study was obtained from surgical patients treated at the Tampere University Hospital in 1983–2009. CARP VIII staining was analyzed in 391 grade I-IV gliomas and CARP XI in 405 gliomas.

Results

CARP VIII immunopositivity was observed in 13% of the astrocytomas and in 9% of the oligodendrogliomas. Positive CARP XI immunostaining was observed in 7% of the astrocytic and in 1% of the oligodendroglial tumor specimens. In our study, the most benign tumors, pilocytic astrocytomas, did not express CARPs at all. In WHO grade II-IV astrocytomas, CARPs were associated with molecular events related to more benign behavior, which was the case with CARP VIII in oligodendrogliomas and oligoastrocytomas as well.

Conclusions

The study observations suggest that the CARPs play a role in tumorigenesis of diffusively infiltrating gliomas. Furthermore, the molecular mechanisms beneath the cancer promoting qualities of CARPs have not yet been discovered. Thus, more studies concerning role of CARPs in oncogenesis are needed.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4493-4) contains supplementary material, which is available to authorized users.

Oncogenic roles of carbonic anhydrase 8 in human osteosarcoma cells

Carbonic anhydrase 8 (CA8), a member of the carbonic anhydrase family, is one of the three isozymes that do not catalyze the reversible hydration of carbon dioxide due to the lack of one important histidine. In the present study, we observed increased expression of CA8 in more aggressive types of human osteosarcoma (OS) cells and found that CA8 expression is correlated with disease stages, such that more intense expression occurs in the disease late stage. We also demonstrated that overexpression of CA8 in human OS (HOS) cells significantly increased cell proliferation both in vitro and in vivo. Downregulated CA8 sensitized cells to apoptotic stress induced by staurosporine and cisplatin, suggesting a specific role of CA8 to protect cells from stresses. In addition, downregulation of CA8 in HOS cells reduced cell invasion and colony formation ability in soft agar and further decreased matrix metalloproteinase 9 and focal adhesion kinase expression, indicating that CA8 might facilitate cancer cell invasion via the activation of FAK-MMP9 signaling. Interestingly, HOS cells with CA8 knockdown showed a significant decrease in glycolytic activity and cell death under glucose withdrawal, further indicating that CA8 may be involved in regulating aerobic glycolysis and enhancing cell viability. Knockdown of CA8 significantly decreased phosphorylated Akt expression suggesting that the oncogenic role of CA8 may be mediated by the regulation of Akt activation through p-Akt induction. Importantly, the inhibition of glycolysis by 2-deoxyglucose sensitized CA8 HOS-CA8-myc cells to cisplatin treatment under low glucose condition, highlighting a new therapeutic option for OS cancer.

Effects of carbonic anhydrase-related protein VIII on human cells harbouring an A8344G mitochondrial DNA mutation

MERRF (myoclonus epilepsy associated with ragged-red fibres) is a maternally inherited mitochondrial encephalomyopathy with various syndromes involving both muscular and nervous systems. The most common mutation in MERRF syndrome, the A8344G mutation in mtDNA, has been associated with severe defects in the respiratory function of mitochondria. In the present study, we show that there is a significant decrease in CA8 (carbonic anhydrase-related protein VIII) in cybrids harbouring the MERRF A8344G mutation. CA8 deficiency and mutations were found to be associated with a distinctive lifelong gait disorder in wdl (Waddles) mice and novel syndromes characterized by cerebellar ataxia and mental retardation in humans. The results of the present study showed that overexpression of CA8 in MERRF cybrids significantly decreased cell death induced by STS (staurosporine) treatment, suggesting a protective function of CA8 in cells harbouring the A8344G mutation of mtDNA. Interestingly, an increase in the formation of LC3-II (microtubule-associated protein 1 light chain 3-II) was found in the cybrids with down-regulated CA8 expression, suggesting that reduced expression of CA8 leads to autophagy activation. Furthermore, cybrids exhibiting down-regulated CA8 showed increased cytosolic Ca2+ signals and reduced levels of phospho-Akt compared with those in the cybrids with overexpressed CA8, indicating that phospho-Akt is involved in the protection of cells by CA8. Our findings suggest that CA8 is involved in the autophagic pathway and may have a protective role in cultured cells from patients with MERRF. Targeting CA8 and the downstream autophagic pathway might help develop therapeutic agents for treatment of MERRF syndrome in the future.

Roles of carbonic anhydrase 8 in neuronal cells and zebrafish

BACKGROUND

Carbonic anhydrase 8 (CA8) is an isozyme of α-carbonic anhydrases (CAs). Previous studies showed that CA8 can be detected in human adult brain, with more intense expression in the cerebellum. Single mutations in CA8 were reported to cause novel syndromes like ataxia, mild mental retardation or the predisposition to quadrupedal gait.

METHODS

In the present study, we examine the functions of CA8 in neuronal cell lines, mouse cerebellar granule neurons and zebrafish.

RESULTS AND CONCLUSIONS

We demonstrated that overexpression of CA8 in neuronal cells significantly decreased cell death under staurosporine treatment. Moreover, CA8 overexpression significantly increased cell migration and invasion ability in neuronal cells and in mouse cerebellar granule neurons, implicating that CA8 may be involved in neuron motility and oncogenesis. By using zebrafish as an animal model, motor reflection of 3dpf zebrafish embryos was significantly affected after the down-regulation of CA8 through ca8 morpholino.

CONCLUSIONS

We concluded that CA8 overexpression desensitizes neuronal cells to STS induced apoptotic stress and increases cell migration and invasion ability in neuronal cells. In addition, down-regulated CA8 decreases neuron mobility in neuronal cells and leads to abnormal calcium release in cerebellar granule neurons. Knockdown of the ca8 gene results in an abnormal movement pattern in zebrafish.

GENERAL SIGNIFICANCE

Our findings provide evidence to support that the impaired protective function of CA8 contributes to human neuropathology, and to suggest that zebrafish can be used as an animal model to study the biological functions of human CA8 in vivo.

Carbonic anhydrase related proteins: molecular biology and evolution

The catalytically inactive isoforms of α-carbonic anhydrases are known as carbonic anhydrase related proteins (CARPs). The CARPs occur independently or as domains of other proteins in animals (both vertebrates and invertebrates) and viruses. The catalytic inactivity of CARPs is due to the lack of histidine residues required for the coordination of the zinc atom. The phylogenetic analysis shows that these proteins are highly conserved across the species. The three CARPs in vertebrates are known as CARP VIII, X and XI. CARPs orthologous to CARP VIII are found in deuterostome invertebrates, whereas protostomes only possess orthologs of CARP X. The CA-like domains of receptor-type protein tyrosine phosphatases (PTPR) are found only in PTPRG and PTPRZ. Most of these CARPs are predominantly expressed in central nervous system. Among the three vertebrate CA isoforms, CARP VIII is functionally associated with motor coordination in human, mouse and zebrafish and certain types of cancers in humans. Vertebrate expression studies show that CARP X is exclusively expressed in the brain. CARP XI is only found in tetrapods and is highly expressed in the central nervous system (CNS) of humans and mice and is also associated with several cancers. CARP VIII, PTPRZ and PTPRG have been shown to coordinate the function of other proteins by protein-protein interaction, and viral CARPs participate in attachment to host cells, but the precise biological function of CARPs X and XI is still unknown. The findings so far suggest many novel functions for the CARP subfamily, most likely related to binding to other proteins.

Mechanisms that determine the internal environment of the developing brain: a transcriptomic, functional and ultrastructural approach

We provide comprehensive identification of embryonic (E15) and adult rat lateral ventricular choroid plexus transcriptome, with focus on junction-associated proteins, ionic influx transporters and channels. Additionally, these data are related to new structural and previously published permeability studies. Results reveal that most genes associated with intercellular junctions are expressed at similar levels at both ages. In total, 32 molecules known to be associated with brain barrier interfaces were identified. Nine claudins showed unaltered expression, while two claudins (6 and 8) were expressed at higher levels in the embryo. Expression levels for most cytoplasmic/regulatory adaptors (10 of 12) were similar at the two ages. A few junctional genes displayed lower expression in embryos, including 5 claudins, occludin and one junctional adhesion molecule. Three gap junction genes were enriched in the embryo. The functional effectiveness of these junctions was assessed using blood-delivered water-soluble tracers at both the light and electron microscopic level: embryo and adult junctions halted movement of both 286Da and 3kDa molecules into the cerebrospinal fluid (CSF). The molecular identities of many ion channel and transporter genes previously reported as important for CSF formation and secretion in the adult were demonstrated in the embryonic choroid plexus (and validated with immunohistochemistry of protein products), but with some major age-related differences in expression. In addition, a large number of previously unidentified ion channel and transporter genes were identified for the first time in plexus epithelium. These results, in addition to data obtained from electron microscopical and physiological permeability experiments in immature brains, indicate that exchange between blood and CSF is mainly transcellular, as well-formed tight junctions restrict movement of small water-soluble molecules from early in development. These data strongly indicate the brain develops within a well-protected internal environment and the exchange between the blood, brain and CSF is transcellular and not through incomplete barriers.

An update on carbonic anhydrase-related proteins VIII, X and XI

The catalytically inactive isoforms of carbonic anhydrase (CAs) are known as CA-related proteins (CARPs) VIII, X, and XI. They have highly conserved amino acid sequences. These proteins are predominantly expressed in human and mouse brain, however, their precise roles are poorly known. CARP VIII is functionally associated with motor coordination in human and mouse. CARP X is more highly expressed in the pineal gland during night compared to the day time, suggesting a function for wake/sleep patterns. Phylogeny shows that CARP XI has emerged from CARP X. It is only found in tetrapods and is highly expressed in the central nervous system (CNS) of humans and is also associated with several cancers. Detailed analysis of CARPs is in progress in our laboratory to understand their role in normal physiology. We present a review of literature on CARPs and present some novel data on CARPs obtained in our laboratory.

Restoring catalytic activity to the human carbonic anhydrase (CA) related proteins VIII, X and XI affords isoforms with high catalytic efficiency and susceptibility to anion inhibition

Mutation of amino acid residues 94, 96 and 119 to histidine(s) in the human carbonic anhydrase (CA, EC 4.2.1.1) related proteins CARP VIII, X and XI restored the zinc binding and catalytic activity for the hydration of CO(2) to bicarbonate. CA VIII, X and XI thus obtained showed high catalytic activity (67.3-92.0% of the activity of hCA II and much higher compared to hCA I) and were inhibited in the milli-micromolar range by inorganic anions, sulfamide, sulfamic acid, phenylboronic acid and phenylarsonic acid. Among the three new isoforms, hCA X was the most efficient enzyme and also showed the highest affinity for anion inhibitors (K(I)s of 3.6-68 μM for phenylboronic acid, sufamic acid, sulfamide, cyanide and azide). hCA VIII was poorly inhibited by halides, cyanate, nitrate and sulfate (K(I)s of 38.4-65.4 mM), whereas CA XI had a behavior intermediate between that of hCA VIII and X, both regarding the catalytic activity and sensitivity to anion inhibitors.

Prednisolone-induced differential gene expression in mouse liver carrying wild type or a dimerization-defective glucocorticoid receptor

BACKGROUND

Glucocorticoids (GCs) control expression of a large number of genes via binding to the GC receptor (GR). Transcription may be regulated either by binding of the GR dimer to DNA regulatory elements or by protein-protein interactions of GR monomers with other transcription factors. Although the type of regulation for a number of individual target genes is known, the relative contribution of both mechanisms to the regulation of the entire transcriptional program remains elusive. To study the importance of GR dimerization in the regulation of gene expression, we performed gene expression profiling of livers of prednisolone-treated wild type (WT) and mice that have lost the ability to form GR dimers (GRdim).

RESULTS

The GR target genes identified in WT mice were predominantly related to glucose metabolism, the cell cycle, apoptosis and inflammation. In GRdim mice, the level of prednisolone-induced gene expression was significantly reduced compared to WT, but not completely absent. Interestingly, for a set of genes, involved in cell cycle and apoptosis processes and strongly related to Foxo3a and p53, induction by prednisolone was completely abolished in GRdim mice. In contrast, glucose metabolism-related genes were still modestly upregulated in GRdim mice upon prednisolone treatment. Finally, we identified several novel GC-inducible genes from which Fam107a, a putative histone acetyltransferase complex interacting protein, was most strongly dependent on GR dimerization.

CONCLUSIONS

This study on prednisolone-induced effects in livers of WT and GRdim mice identified a number of interesting candidate genes and pathways regulated by GR dimers and sheds new light onto the complex transcriptional regulation of liver function by GCs.

Phylogeny and expression of carbonic anhydrase-related proteins

Background

Carbonic anhydrases (CAs) are found in many organisms, in which they contribute to several important biological processes. The vertebrate α-CA family consists of 16 subfamilies, three of which (VIII, X and XI) consist of acatalytic proteins. These are named carbonic anhydrase related proteins (CARPs), and their inactivity is due to absence of one or more Zn-binding histidine residues. In this study, we analyzed and evaluated the distribution of genes encoding CARPs in different organisms using bioinformatic methods, and studied their expression in mouse tissues using immunohistochemistry and real-time quantitative PCR.

Results

We collected 84 sequences, of which 22 came from novel or improved gene models which we created from genome data. The distribution of CARP VIII covers vertebrates and deuterostomes, and CARP X appears to be universal in the animal kingdom. CA10-like genes have had a separate history of duplications in the tetrapod and fish lineages. Our phylogenetic analysis showed that duplication of CA10 into CA11 has occurred only in tetrapods (found in mammals, frogs, and lizards), whereas an independent duplication of CA10 was found in fishes. We suggest the name CA10b for the second fish isoform. Immunohistochemical analysis showed a high expression level of CARP VIII in the mouse cerebellum, cerebrum, and also moderate expression in the lung, liver, salivary gland, and stomach. These results also demonstrated low expression in the colon, kidney, and Langerhans islets. CARP X was moderately expressed in the cerebral capillaries and the lung and very weakly in the stomach and heart. Positive signals for CARP XI were observed in the cerebellum, cerebrum, liver, stomach, small intestine, colon, kidney, and testis. In addition, the results of real-time quantitative PCR confirmed a wide distribution for the Car8 and Car11 mRNAs, whereas the expression of the Car10 mRNA was restricted to the frontal cortex, parietal cortex, cerebellum, midbrain, and eye.

Conclusions

CARP sequences have been strongly conserved between different species, and all three CARPs show high expression in the mouse brain and CARP VIII is also expressed in several other tissues. These findings suggest an important functional role for these proteins in mammals.

Chromosomal imbalances and partial uniparental disomies in primary central nervous system lymphoma

To determine the pattern of genetic alterations in primary central nervous system lymphomas (PCNSL), 19 PCNSL were studied by high-density single-nucleotide polymorphism arrays. Recurrent losses involved 6p21.32, 6q21, 8q12-12.2, 9p21.3, 3p14.2, 4q35.2, 10q23.21 and 12p13.2, whereas gains involved 18q21-23, 19q13.31, 19q13.43 and the entire chromosomes X and 12. Partial uniparental disomies (pUPDs) were identified in 6p and 9p21.3. These genomic alterations affected the HLA locus, the CDKN2A/p16, CDKN2B/p15 and MTAP, as well as the PRDM1, FAS, MALT1, and BCL2 genes. Increased methylation values of the CDKN2A/p16 promoter region were detected in 75% (6/8) PCNSL. Gene expression profiling showed 4/21 (20%) minimal common regions of imbalances to be associated with a differential mRNA expression affecting the FAS, STAT6, CD27, ARHGEF6 and SEPT6 genes. Collectively, this study unraveled novel genomic imbalances and pUPD with a high resolution in PCNSL and identified target genes of potential relevance in the pathogenesis of this lymphoma entity.

Identification of uterine leiomyoma genes developmentally reprogrammed by neonatal exposure to diethylstilbestrol

Environmental exposures during development can alter susceptibility later in life to adult diseases including uterine leiomyoma, a phenomenon termed developmental reprogramming. The goal of this study was to identify genes developmentally reprogrammed by diethylstilbestrol (DES) and aberrantly expressed in leiomyomas. Transcriptional profiling identified 171 genes differentially expressed in leiomyomas relative to normal myometrium, of which 6/18 genes with putative estrogen responsive elements and confirmed to be estrogen-responsive in neonatal uteri were reprogrammed by neonatal DES exposure. Calbindin D9k and Dio2, normally induced by estrogen, exhibited elevated expression in DES-exposed animals during both phases of the estrus cycle. Gdf10, Car8, Gria2, and Mmp3, genes normally repressed by estrogen, exhibited elevated expression in DES-exposed animals during the proliferative phase, when estrogen is highest. These data demonstrate that neonatal DES exposure causes reprogramming of estrogen-responsive genes expressed in uterine leiomyomas, leading to over-expression of these genes in the myometrium of exposed animals prior to the onset of tumorigenesis.