Expression Of CRABP1 Research Articles

Effect of CRABP1 expression on the proliferation and the sensitivity to retionoic acid of breast cancer cells of different origin

Background.Retinoic acid (RA), by modulation of the transcription of a number of retinoid-responsive genes, is involved in the regulation of cell differentiation and proliferation. The mechanisms by which the RA-binding proteins, molecular chaperones CRABP1 and CRABP2 (Cellular Retinoic Acid Proteins-1 and -2), participate in the realization of RA activity, as well as their precise role in tumor progression are still not fully understood. Recent data indicate that functional differences of CRABP proteins with respect to malignization of breast cancer cells could be determined by different sensitivity of tumor cells to RA and with the receptor status of the tumor.Materials and methods.The CRABP1 coding sequence was overexpressed in breast cancer cells without endogenous expression of this protein, with different levels of RA sensitivity and receptor status – SKBR3 (RA-sensitive, ER(–) / HER2(+) cells) and MDA-MB-231 (RA-resistant, triple negative status). The growth of CRABP1(+) derivatives and control cells was evaluated under standard culture conditions and in the presence of various concentrations of RA.Results.The effect of CRABP1 expression in RA-sensitive and RA-resistant breast cancer cells with different receptor status on the growth rate and sensitivity of cells to RA was studied. The expression of CRABP1 in RA-sensitive SKBR3 cells enhances proliferation in the absence of RA and decreases the antiproliferative effect of RA, while in RA-resistant triple-negative MDA-MB-231 cells, the expression of CRABP1 does not affect the studied characteristics.Conclusion.CRABP1 stimulates growth and suppresses the RA-sensitivity of HER2(+) RA-sensitive cells, but does not have a similar effect on highly aggressive triple-negative RA-resistant cells.

Correlation between Plasma Cellular Retinoic Acid-Binding Protein 2 and Proliferation, Migration, and Invasion of Non-Small-Cell Lung Cancer Cells.

Our primary aim of the current study was to explore the correlation between plasma CRABP2 and migration, proliferation and invasion of non-small cell lung cancer (NSCLC) cells. Human lung cancer cell line A549 was used in the present study, which was cultured in 6-well plates (1 × 106 cells/well) and then transfected with pcDNA-CRABP2 and pcDNA, siRNA with the use of Lipofectamine 2000 based on the manufacturer's protocol. The expression of CRABP2 mRNA was detected through real-time PCR. Proliferation was further detected using MTT assays, and apoptosis was monitored and recorded with the application of flow cytometry. The expression of E-cadherin, MMP9, vimentin and related pathway proteins was detected by Western blotting assays. Transwell assays and cell scratch assays were utilized for the detection of migration and invasion ability of A549 cells. RT-PCR results showed The CRABP2 mRNA transcript levels in the CRABP2 overexpression group were higher when comparing those of the empty vector group (P < 0.05). By MTT assays, CRABP2 overexpression promoted cellular proliferation, while CRABP2 downregulation inhibited cellular proliferation. CRABP2 overexpression inhibited cell apoptosis and promoted cellular proliferation. The number of TUNEL staining positive cells was the lowest in the CRABP2 overexpression group, and the siRNA transfection group had increased apoptosis. CRABP2 downregulation reduced EMT in cells and cell migration and invasion reflected from western blotting results and cell migration and invasion assay results, respectively. Inhibition of plasma CRABP2 expression offers the potential in terms of reducing the expression of MAPKs and proteins in the NF-κB pathway and inhibiting the proliferation and migration of NSCLC cells, which is ideally suited for further treatment for NSCLC.

The Molecular Effects of a High Fat Diet on Endometrial Tumour Biology.

We sought to validate the BDII/Han rat model as a model for diet-induced obesity in endometrial cancer (EC) and determine if transcriptomic changes induced by a high fat diet (HFD) in an EC rat model can be used to identify novel biomarkers in human EC. Nineteen BDII/Han rats were included. Group A (n = 7) were given ad lib access to a normal calorie, normal chow diet (NCD) while Group B (n = 12) were given ad lib access to a calorie rich HFD for 15 months. RNAseq was performed on endometrial tumours from both groups. The top-ranking differentially expressed genes (DEGs) were examined in the human EC using The Cancer Genome Atlas (TCGA) to assess if the BDII/Han rat model is an appropriate model for human obesity-induced carcinogenesis. Weight gain in HFD rats was double the weight gain of NCD rats (50 g vs. 25 g). The incidence of cancer was similar in both groups (4/7—57% vs. 4/12—33%; p = 0.37). All tumours were equivalent to a Stage 1A, Grade 2 human endometrioid carcinoma. A total of 368 DEGs were identified between the tumours in the HFD group compared to the NCD group. We identified two upstream regulators of the DEGs, mir-33 and Brd4, and a pathway analysis identified downstream enrichment of the colorectal cancer metastasis and ovarian cancer metastasis pathways. Top-ranking DEGs included Tex14, A2M, Hmgcs2, Adamts5, Pdk4, Crabp2, Capn12, Npw, Idi1 and Gpt. A2M expression was decreased in HFD tumours. Consistent with these findings, we found a significant negative correlation between A2M mRNA expression levels and BMI in the TCGA cohort (Spearman’s Rho = −0.263, p < 0.001). A2M expression was associated with improved overall survival (HR = 0.45, 95% CI 0.23–0.9, p = 0.024). Crabp2 expression was increased in HFD tumours. In human EC, CRABP2 expression was associated with reduced overall survival (HR = 3.554, 95% CI 1.875–6.753, p < 0.001). Diet-induced obesity can alter EC transcriptomic profiles. The BDII/Han rat model is a suitable model of diet-induced obesity in endometrial cancer and can be used to identify clinically relevant biomarkers in human EC.

Interspecies transcriptome analyses identify genes that control the development and evolution of limb skeletal proportion

Despite the great diversity of vertebrate limb proportion and our deep understanding of the genetic mechanisms that drive skeletal elongation, little is known about how individual bones reach different lengths in any species. Here, we directly compare the transcriptomes of homologous growth cartilages of the mouse (Mus musculus) and bipedal jerboa (Jaculus jaculus), which has extremely long metatarsals of the feet and ‘mouse‐like’ arms. When we intersected gene expression differences in metatarsals of the two species with expression differences in forearms, we found that about 10% of all orthologous genes are associated with disproportionate elongation of jerboa feet. Among these, Shox2, has gained expression in jerboa metatarsals where it is not expressed in other vertebrates that have been assessed. This transcription factor is necessary for proximal limb elongation, and we show that it is sufficient to increase mouse distal limb length. Unexpectedly, we also found evidence that jerboa foot elongation occurs in part by releasing latent growth potential that is repressed in mouse feet. In jerboa metatarsals, we observed higher expression of Crabp1, an antagonist of growth inhibitory retinoic acid, lower expression of Gdf10, an inhibitory TGFβ ligand, and lower expression of Mab21L2, a BMP signaling inhibitor that we show is sufficient to reduce limb bone elongation. By intersecting our data with prior expression analyses in other systems, we identify mechanisms that may both establish limb proportion during development and diversify proportion during evolution. The genes we identified here therefore provide a framework to understand the modular genetic control of skeletal growth and the remarkable malleability of vertebrate limb proportion.Support or Funding InformationThis work used the Extreme Science and Engineering Discovery Environment(XSEDE) at SDSC, which is supported by National Science Foundation grant number ACI1548562. This work was also supported by Natural Sciences and Engineering Research Council grant RGPIN/355731‐2013 to JC and by a Searle Scholar Award from the Kinship Foundation, a Pew Biomedical Scholar Award from the Pew Charitable Trusts, a Packard Fellowship in Science and Engineering from the David and Lucile Packard Foundation, and the National Institutes of Health under award number R01AR075415 awarded to KLC.

Efficacy of Quercetin-sensitized Adriamycin for Treatment of Refractory Acute Leukemia

To investigate the chemotherapeutic efficency of quercetin sensitized adriamycin. CCK-8 was used to detect the inhibitory effect of different doses of adriamycin, quercetin and quercetin combined with adriamycin on the proliferation of primary leukemia cells from patients with clinically refractory acute leukemia. Quercetin, adriamycin and their combination were used to treat non-irradiated T-ALL leukemia mice to observe the changes of survival curve and myocardial injury. There was no significant difference in the inhibition rate of primary leukemia cell proliferation between the adriamycin concentration group (6, 0.6 and 0.06 μg/ml) and the adriamycin half-dose (3, 0.3 and 0.03 μg/ml) plus quercetin (0.25 mmol/L) group at three different time points (24, 48 and 72 hours). There was a significant difference in the inhibition rate of primary leukemia cell proliferation among the drug concentration groups, and the inhibition rate of primary leukemia cell proliferation was time-and concentration-dependent (r24h，a\c\e=0.995、r48h，a\c\e=1.000、r72h，a\c\e=0.984、r24h，b\d\f=0.993、r48h，b\d\f=0.999、r72h，b\d\f=0.960). In vivo experiments showed that the survival time of non-irradiated T-ALL leukemia mice treated with low-dose adriamycin combined with quercetin was not significantly prolonged compared with the high-dose adriamycin treatment group. The survival time of non-irradiated T-ALL leukemia mice treated with high dose of adriamycin and quercetin was significantly prolonged (P＜0.05). Compared with adriamycin group, the SOD activity in adriamycin combined with quercetin group increased significantly and the MDA content decreased. The results of transcriptome sequencing analysis showed that the expression of Ighv1-84 and Igkv6-14 in adriamycin combined quercetin group and quercetin group was lower than that in adriamycin group. The Ms4a1, Podx1, Mecom, Sh3bgr12, Bex4 and Tdrp expression in adriamycin combined quercetin group and adriamycin group were higher than that in quercetin group, while Crabp1 expression was lower. Quercetin can inhibit the proliferation of primary leukemia cells in a time-dependent manner. Quercetin combined with adriamycin inhibit the proliferation of primary leukemia cells significantly, and had synergistic and additive effects on the proliferation of primary leukemia cells, and the inhibiting effect of quercetin combined with adriamycin is concentration-and time-dependent. Quercetin combined with high-dose adriamycin can significantly prolong the survival time of non-irradiated T-ALL leukemia mice and reduce the myocardial damage caused by adriamycin.

Crabp2 Promotes Metastasis of Lung Cancer Cells via HuR and Integrin \u03b21/FAK/ERK Signaling

Increased Crabp2 levels have been found in various types of cancer, and are associated with poor patients’ survival. Although Crabp2 is found to be overexpressed in lung cancer, its role in metastasis of lung cancer is unclear. In this study, Crabp2 was overexpressed in high-metastatic C10F4 than low-metastatic lung cancer cells. Analysis of clinical samples revealed that high CRABP2 levels were correlated with lymph node metastases, poor overall survival, and increased recurrence. Knockdown of Crabp2 decreased migration, invasion, anoikis resistance, and in vivo metastasis. Crabp2 was co-immunoprecipitated with HuR, and overexpression of Crabp2 increased HuR levels, which promoted integrin β1/FAK/ERK signaling. Inhibition of HuR or integrin β1/FAK/ERK signaling reversed the promoting effect of Crabp2 in migration, invasion, and anoikis resistance. Knockdown of Crabp2 further inhibited the growth of cancer cells as compared with that by gemcitabine or irinotecan alone. The expression of Crabp2 in human lung tumors was correlated with stress marker CHOP. In conclusion, our findings have identified the promoting role of Crabp2 in anoikis resistance and metastasis. CRABP2 may serve as a prognostic marker and targeting CRABP2 may be exploited as a modality to reduce metastasis.

Prolonged prenatal hypoxia selectively disrupts collecting duct patterning and postnatal function in male mouse offspring.

In the present study, we investigated whether hypoxia during late pregnancy impairs kidney development in mouse offspring, and also whether this has long-lasting consequences affecting kidney function in adulthood. Hypoxia disrupted growth of the kidney, particularly the collecting duct network, in juvenile male offspring. By mid-late adulthood, these mice developed early signs of kidney disease, notably a compromised response to water deprivation. Female offspring showed no obvious signs of impaired kidney development and did not develop kidney disease, suggesting an underlying protection mechanism from the hypoxia insult. These results help us better understand the long-lasting impact of gestational hypoxia on kidney development and the increased risk of chronic kidney disease. Prenatal hypoxia is a common perturbation to arise during pregnancy, and can lead to adverse health outcomes in later life. The long-lasting impact of prenatal hypoxia on postnatal kidney development and maturation of the renal tubules, particularly the collecting duct system, is relatively unknown. In the present study, we used a model of moderate chronic maternal hypoxia throughout late gestation (12% O2 exposure from embryonic day 14.5 until birth). Histological analyses revealed marked changes in the tubular architecture of male hypoxia-exposed neonates as early as postnatal day 7, with disrupted medullary development and altered expression of Ctnnb1 and Crabp2 (encoding a retinoic acid binding protein). Kidneys of the RARElacZ line offspring exposed to hypoxia showed reduced β-galactosidase activity, indicating reduced retinoic acid-directed transcriptional activation. Wild-type male mice exposed to hypoxia had an early decline in urine concentrating capacity, evident at 4months of age. At 12months of age, hypoxia-exposed male mice displayed a compromised response to a water deprivation challenge, which was was correlated with an altered cellular composition of the collecting duct and diminished expression of aquaporin2. There were no differences in the tubular structures or urine concentrating capacity between the control and hypoxia-exposed female offspring at any age. The findings of the present study suggest that prenatal hypoxia selectively disrupts collecting duct patterning through altered Wnt/β-catenin and retinoic acid signalling and this results in impaired function in male mouse offspring in later life.

CRABP1 and 2 differentially regulate HCV infection via modulation of lipid droplet abundance.

Abstract Vitamin A is an essential nutritional constituent that governs a broad spectrum of cell biology through the activation of its nuclear receptor complexes. The active metabolite of vitamin A, all-trans retinoic acid (ATRA), binds to the chaperone molecule, cytoplasmic retinoic acid binding protein (CRABP) 1 or 2 to regulate its signaling pathways. Given the extremely high homology, CRABP1 and 2 have been predicted to play a redundant role. However, a few studies by others suggested that CRABP1 and 2 might differentially regulate the cellular response to ATRA. Although the antiviral effect of ATRA is well recognized, the roles of CRABPs in the regulation of viral pathogens have never been studied. In this study, we employed hepatitis C virus (HCV) as a study model to assess the importance of CRABPs. Of great interest, CRABP1 expression enhanced HCV infection while CRABP2 expression resulted in the suppression of HCV lifecycle. Our follow up studies collectively indicated that CRABPs regulate the efficiency of HCV infection through the modulation of lipid droplet (LD) abundance wherein HCV establishes the replicase complex. The transcriptome analysis revealed that CRABP1 expression downregulated the genes regulated by ATRA and is associated with the expression of genes involved in the steatosis of the liver. In contrast, CRABP2 expression augmented ATRA response, resulting in the inhibition of LD accumulation. Moreover, the chemical inhibition of the CRABP1 and 2 pathways resulted in the abrogation of their pro- and antiviral effect, respectively. In conclusion, our study revealed a novel link between the cellular response to the micronutrients and its influence on the viral infectious disease.

MEK inhibitors enhance therapeutic response towards ATRA in NF1 associated malignant peripheral nerve sheath tumors (MPNST) in-vitro.

ObjectiveNeurofibromatosis type 1 (NF1) is a hereditary tumor syndrome characterized by an increased risk of malignant peripheral nerve sheath tumors (MPNST). Chemotherapy of MPNST is still insufficient. In this study, we investigated whether human tumor Schwann cells derived from NF1 associated MPNST respond to all-trans retinoic acid (ATRA). We analyzed effects of ATRA and MEK inhibitor (MEKi) combination therapy.MethodsMPNST cell lines S462, T265, NSF1 were treated with ATRA and MEKi U0126 and PD0325901. We assessed cell viability, proliferation, migration, apoptosis and differentiation as well as mRNA expression of RAR and RXR subtypes and ATRA target genes such as CRABP2, CYP26A1, RARB and PDK1. We also analyzed CRABP2 methylation in cell lines and performed immunohistochemistry of human MPNST specimens.ResultsATRA therapy reduced viability and proliferation in S462 and T265 cells, accompanied by differentiation, apoptosis and reduced migration. NSF1 cells which lacked RXRG expression did not respond to ATRA. We furthermore demonstrated that ATRA signaling was functional for common targets, and that mRNA expression of CRABP2 and its targets was raised by ATRA therapy, whereas alternative pathways via FABP5 were not induced. Finally, combination of ATRA and MEKi demonstrated additively reduced viability of T265 and S462 cells.ConclusionsWe observed therapeutic effects in two of three MPNST cell lines pronounced by combination therapy. These data point to a potentially successful treatment of MPNST by combined application of ATRA and MEK inhibitors such as U0126 or PD0325901.

Cross platform analysis of transcriptomic data identifies ageing has distinct and opposite effects on tendon in males and females

The development of tendinopathy is influenced by a variety of factors including age, gender, sex hormones and diabetes status. Cross platform comparative analysis of transcriptomic data elucidated the connections between these entities in the context of ageing. Tissue-engineered tendons differentiated from bone marrow derived mesenchymal stem cells from young (20–24 years) and old (54–70 years) donors were assayed using ribonucleic acid sequencing (RNA-seq). Extension of the experiment to microarray and RNA-seq data from tendon identified gender specific gene expression changes highlighting disparity with existing literature and published pathways. Separation of RNA-seq data by sex revealed underlying negative binomial distributions which increased statistical power. Sex specific de novo transcriptome assemblies generated fewer larger transcripts that contained miRNAs, lincRNAs and snoRNAs. The results identify that in old males decreased expression of CRABP2 leads to cell proliferation, whereas in old females it leads to cellular senescence. In conjunction with existing literature the results explain gender disparity in the development and types of degenerative diseases as well as highlighting a wide range of considerations for the analysis of transcriptomic data. Wider implications are that degenerative diseases may need to be treated differently in males and females because alternative mechanisms may be involved.

13cRA regulates the differentiation of antler chondrocytes through targeting Runx3.

Although 13cRA is involved in the regulation of cellular proliferation and differentiation, its physiological roles in chondrocyte proliferation and differentiation still remain unknown. Here, we showed that 13cRA could induce the proliferation of sika deer antler chondrocytes and expression of Ccnd3 and Cdk6. Administration of 13cRA to antler chondrocytes resulted in an obvious increase in the expression of chondrocyte marker Col II and hypertrophic chondrocyte marker Col X. Silencing of Crabp2 expression by specific siRNA could prevent the 13cRA-induced up-regulation of Col X, whereas overexpression of Crabp2 showed the opposite effects. Further study found that Crabp2 mediated the regulation of 13cRA on the expression of Runx3 which was highly expressed in the antler cartilage and inhibited the differentiation of antler chondrocytes. Moreover, attenuation of Runx3 expression greatly raised 13cRA-induced chondrocyte differentiation. Simultaneously, 13cRA could stimulate the expression of Cyp26a1 and Cyp26b1 in the antler chondrocytes. Inhibition of Cyp26a1 and/or Cyp26b1 reinforced the effects of 13cRA on the expression of Col X and Runx3, while overexpression of Cyp26b1 rendered the antler chondrocytes hyposensitive to 13cRA. Collectively, 13cRA may play an important role in the differentiation of antler chondrocytes through targeting Runx3. Crabp2 enhances the effects of 13cRA on chondrocyte differentiation, while Cyp26a1 and Cyp26b1 weaken the sensitivity of antler chondrocytes to 13cRA.

90 OVIDUCTAL EPITHELIAL CELLS Co-CULTURE PROMOTES GOAT (CAPRA HIRCUS) IN VITRO PARTHENOGENETIC EMBRYO DEVELOPMENT

Co-culture of pre-implantation embryos with oviducal epithelial cells mimics the in vivo conditions, thus, playing a crucial role in embryo metabolism and gene expression and finally supporting embryonic developmental competence in several ways. Hence, the objective of the present study was to evaluate the effect of goat oviducal epithelial cells (GOEC) co-culture on goat parthenogenetic embryonic development, quality, and relative mRNA abundance of genes related to developmental competence and oxidative stress. The GOEC were obtained from goat oviducts by squeezing and thorough washing with TCM-199 + 10% fetal bovine serum. Goat cumulus–oocyte complexes were collected from slaughterhouse ovaries and matured in TCM-199 + 10% fetal bovine serum supplemented with 5 μg mL−1 of FSH, 10 μg mL−1 of LH, and 1 μg mL−1 of β-oestradiol for 27 h in CO2 incubator with 5% CO2 and at 38.5°C with &gt;95% RH. In vitro matured cumulus–oocyte complexes were denuded and activated with 5 μM calcium ionophore and 2 mM 6-DMAP. Following activation, embryos were co-cultured with and without GOEC (control) in mCR2aa media. The blastocyst development rate was significantly (P &lt; 0.05) higher (23.00 ± 1.15% v. 17.33 ± 1.45%) in the media cultured with GOEC than in control. The total cell number of blastocysts (n = 4) was also found to be significantly more (167.25 ± 17.51 v. 110.25 ± 12.02) than that of control (P &lt; 0.05). However, the apoptotic index (3.76 ± 0.23% v. 7.97 ± 1.99%) was not significantly different in both groups. Further, RNA was isolated from both groups (20 each) of blastocysts on Day 8, and cDNA was prepared. Analysis by qPCR revealed that the relative mRNA abundance of development related genes, i.e. VEGF, BMP4, and CCNB1, showed significantly high (P &lt; 0.05) expression, whereas the expression of CRABP1 was significantly low (P &lt; 0.05) in GOEC co-culture than control. Oxidative stress related genes GPX-1 and SOD2 had comparable expression in both the culture systems, whereas a nonsignificant (P &lt; 0.05) increase in expression of PRDX1 was observed in GOEC co-culture group. In conclusion, co-culture of embryos with GOEC in the simple culture media like mCR2aa helps in improving developmental competence and quality of parthenogenetic embryos. This work was supported by the NFBSFARA Project on Parthenogenetic Goat (CA-4002), New Delhi, India.

Corrigendum: All trans-retinoic acid analogs promote cancer cell apoptosis through non-genomic Crabp1 mediating ERK1/2 phosphorylation.

Scientific Reports 6: Article number: 22396; published online: 03 March 2016; updated: 20 July 2016 This Article contains errors. In the last paragraph of the Results section, “Given the ability of atRA and compounds 3 and 4 to induce apoptosis in animal cancer cell line context, we surveyed severalhuman cell lines and found that CRABP1 expression was lost in human ovarian cancer cell line A2780 and human pancreatic ductal carcinoma cell line KPC”.

Cell Line-Dependent Variability of Coordinate Expression of p75NTR and CRABP1 and Modulation of Effects of Fenretinide on Neuroblastoma Cells.

Neuroblastoma is a childhood neural crest tumor. Fenretinide, a retinoic acid analogue, induces accumulation of mitochondrial reactive oxygen species and consequent apoptosis in neuroblastoma cells. The p75 neurotrophin receptor (p75NTR) enhances the antineuroblastoma cell efficacy of fenretinide in vitro. We examined the role of the retinoid binding protein, CRABP1, in p75NTR-mediated potentiation of the efficacy of fenretinide. Knockdown and overexpression, respectively, of either p75NTR or CRABP1 were effected in neuroblastoma cell lines using standard techniques. Expression was determined by qRT-PCR and confirmed at the protein level by Western blot. Metabolic viability was determined by Alamar blue assay. While protein content of CRABP1 correlated roughly with that of p75NTR in the three neuroblastoid or epithelioid human neuroblastoma cell lines studied, manipulation of p75NTR expression resulted in cell line-dependent, variable change in CRABP1 expression. Furthermore, in some cell lines, induced expression of CRABP1 in the absence of p75NTR did not alter cell sensitivity to fenretinide treatment. The effects of manipulation of p75NTR expression on CRABP1 expression and the effects of CRABP1 expression on fenretinide efficacy are therefore neuroblastoma cell line-dependent. Potentiation of the antineuroblastoma cell effects of fenretinide by p75NTR is not mediated solely through CRABP1.

CRABP1 is associated with a poor prognosis in breast cancer: adding to the complexity of breast cancer cell response to retinoic acid.

BackgroundClinical trials designed to test the efficacy of retinoic acid (RA) as an adjuvant for the treatment of solid cancers have been disappointing, primarily due to RA resistance. Estrogen receptor (ER)-negative breast cancer cells are more resistant to RA than ER-positive cells. The expression and subcellular distribution of two RA-binding proteins, FABP5 and CRABP2, has already been shown to play critical roles in breast cancer cell response to RA. CRABP1, a third member of the RA-binding protein family, has not previously been investigated as a possible mediator of RA action in breast cancer.MethodsCRABP1 and CRABP2 expression in primary breast tumor tissues was analyzed using gene expression and tissue microarrays. CRABP1 levels were manipulated using siRNAs and by transient overexpression. RA-induced subcellular translocation of CRABPs was examined by immunofluorescence microscopy and immunoblotting. RA-induced transactivation of RAR was analyzed using a RA response element (RARE)-driven luciferase reporter system. Effects of CRABP1 expression and RA treatment on downstream gene expression were investigated by semi-quantitative RT-PCR analysis.ResultsCompared to normal mammary tissues, CRABP1 expression is significantly down-regulated in ER+ breast tumors, but maintained in triple-negative breast cancers. Elevated CRABP1 levels are associated with poor patient prognosis, high Ki67 immunoreactivity and high tumor grade in breast cancer. The prognostic significance of CRABP1 is attributed to its cytoplasmic localization. We demonstrate that CRABP1 expression attenuates RA-induced cell growth arrest and inhibits RA signalling in breast cancer cells by sequestering RA in the cytoplasm. We also show that CRABP1 affects the expression of genes involved in RA biosynthesis, trafficking and metabolism.ConclusionsCRABP1 is an adverse factor for clinical outcome in triple-negative breast cancer and a potent inhibitor of RA signalling in breast cancer cells. Our data indicate that CRABP1, in conjunction with previously identified CRABP2 and FABP5, plays a key role in breast cancer cell response to RA. We propose that these three RA-binding proteins can serve as biomarkers for predicting triple-negative breast cancer response to RA, with elevated levels of either cytoplasmic CRABP1 or FABP5 associated with RA resistance, and elevated levels of nuclear CRABP2 associated with sensitivity to RA.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-015-0380-7) contains supplementary material, which is available to authorized users.

Fenretinide: a potential treatment for endometriosis

Fenretinide: a potential treatment for endometriosis

Expression and clinical significance of CRABP1 and CRABP2 in non-small cell lung cancer.

The impairment of retinoic acid (RA)-dependent signaling is a frequent event during carcinogenesis. Cellular retinoic acid-binding proteins (CRABP1 and CRABP2) are important modulators of RA activity. Up to date, the role of these proteins in cancer progression remains poorly investigated. Here, we studied for the first time the simultaneous messenger RNA (mRNA) and protein expression of CRABPs in non-small cell lung cancer (NSCLC) samples. CRABP1 and CRABP2 mRNA levels were elevated in 42 and 56 % of NSCLC samples, respectively. Decrease of CRABP2 mRNA expression was significantly associated with the presence of lymph node metastases. Protein expression of CRABP1 and CRABP2 was detected in 50 and 56 % of tumor samples, respectively. We also found a positive correlation between CRABP1 and CRABP2 expression. Taken together, we demonstrated significant changes in CRABP expression in NSCLC samples. Importantly, the presented data provide the first evidence of potential involvement of CRABP2 in lung cancer metastasis.

RNA sequencing identifies novel markers of non-small cell lung cancer

IntroductionThe development of reliable gene expression profiling technology increasingly impacts our understanding of lung cancer biology. Here, we used RNA sequencing (RNA-Seq) to compare the transcriptomes of non-small cell lung cancer (NSCLC) and normal lung tissues and to investigate expression in lung cancer tissues. MethodsWe enrolled 88 male patients (mean age, 61.2 years) with NSCLC. RNA-Seq was performed on 88 pairs of NSCLC tumor tissue and non-tumor tissue from 54 patients with adenocarcinoma and 34 patients with squamous cell carcinoma. Immunohistochemistry was performed to validate differential candidate gene expression in a different NSCLC group. ResultsRNA-Seq produced 25.41×106 (±8.90×106) reads in NSCLC tissues and 24.70×106 (±4.70×106) reads in normal lung tissues [mean (±standard deviation)]. Among the genes expressed in both tissues, 335 were upregulated and 728 were downregulated ≥2-fold (p<0.001). Four upregulated genes – CBX3, GJB2, CRABP2, and DSP – not previously reported in lung cancer were studied further. Their altered expression was verified by immunohistochemistry in a different set of NSCLC tissues (n=154). CBX3 was positive in 90.3% (139 cases) of the samples; GJB2, in 22.7% (35 cases); CRABP2, in 72.1% (111 cases); and DSP, in 17.5% (27 cases). The positive rate of CRABP2 was higher in adenocarcinoma than squamous cell carcinoma (p<0.01). ConclusionsCBX3 and CRABP2 expression was markedly increased in lung cancer tissues and especially CRABP2 may be promising candidate genes in lung adenocarcinoma.

Proteomic Profiling of Germ Cell Cancer Cells Treated with Aaptamine, a Marine Alkaloid with Antiproliferative Activity

Aaptamine is a marine compound isolated from the sponge Aaptos aaptos showing antiproliferative properties via an undefined mode of action. We analyzed the effects of aaptamine treatment on the proliferation and protein expression of the pluripotent human embryonal carcinoma cell line NT2. Effects on proliferation, cell cycle distribution, and induction of apoptosis were analyzed. At lower concentrations, including the IC50 of 50 μM, aaptamine treatment resulted in a G2/M phase cell cycle arrest, whereas at higher concentrations, induction of apoptosis was seen. Differentially expressed proteins were assessed by 2D-PAGE and mass spectrometry, followed by verification and analysis of protein modifications of the most significantly up- and down-regulated proteins. Aaptamine treatment at the IC50 for 48 h resulted in alteration of 10 proteins, of which five each showed up- and down-regulation. Changes in the 2D map were frequently noticed as a result of post-transcriptional modifications, e.g., of the hypusine modification of the eukaryotic initiation factor 5A (eIF5A). Observed alterations such as increased expression of CRABP2 and hypusination of eIF5A have previously been identified during differentiation of pluripotent cells. For the first time, we describe changes in protein expression caused by aaptamine, providing valuable information regarding the mode of action of this compound.

Temporal blastemal cell gene expression analysis in the kidney reveals new Wnt and related signaling pathway genes to be essential for Wilms' tumor onset

Wilms' tumors (WTs) originate from metanephric blastema cells that are unable to complete differentiation, resulting in triphasic tumors composed of epithelial, stromal and blastemal cells, with the latter harboring molecular characteristics similar to those of the earliest kidney development stages. Precise regulation of Wnt and related signaling pathways has been shown to be crucial for correct kidney differentiation. In this study, the gene expression profile of Wnt and related pathways was assessed in laser-microdissected blastemal cells in WTs and differentiated kidneys, in human and in four temporal kidney differentiation stages (i.e. E15.5, E17.5, P1.5 and P7.5) in mice, using an orthologous cDNA microarray platform. A signaling pathway-based gene signature was shared between cells of WT and of earliest kidney differentiation stages, revealing genes involved in the interruption of blastemal cell differentiation in WT. Reverse transcription-quantitative PCR showed high robustness of the microarray data demonstrating 75 and 56% agreement in the initial and independent sample sets, respectively. The protein expression of CRABP2, IGF2, GRK7, TESK1, HDGF, WNT5B, FZD2 and TIMP3 was characterized in WTs and in a panel of human fetal kidneys displaying remarkable aspects of differentiation, which was recapitulated in the tumor. Taken together, this study reveals new genes candidate for triggering WT onset and for therapeutic treatment targets.