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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Plasma CRABP2 as a Novel Biomarker in Patients with Non-Small Cell Lung Cancer.

BACKGROUND: Lung cancer is the most common cause of cancer-related mortality worldwide. We previously reported the identification of a new genetic marker, cellular retinoic acid binding protein 2 (CRABP2), in lung cancer tissues. The aim of this study was to assess plasma levels of CRABP2 from patients with non-small cell lung cancer (NSCLC). METHODS: Blood samples that were collected from 122 patients with NSCLC between September 2009 and September 2013 were selected for the analysis, along with samples from age- (± 5 years), sex-, and cigarette smoking history (± 10 pack-years [PY])-matched controls from the Korea Biobank Network. The control specimens were from patients who were without malignancies or pulmonary diseases. We measured plasma levels of CRABP2 using commercially available enzyme-linked immunosorbent assay kits. RESULTS: The mean age of the NSCLC patients was 71.8 ± 8.9 years, and the median cigarette smoking history was 32 PY (range, 0-150 PY). Plasma CRABP2 levels were significantly higher in patients with NSCLC than in the matched controls (37.63 ± 28.71 ng/mL vs. 24.09 ± 21.09 ng/mL, P < 0.001). Higher plasma CRABP2 levels were also correlated with lower survival rates in NSCLC patients (P = 0.014). CONCLUSION: Plasma CRABP2 levels might be a novel diagnostic and prognostic marker in NSCLC.

Increased Th17 functions are accompanied by Tregs activities in lupoid leishmaniasis.

The immunopathogenesis of lupoid leishmaniasis is challenging. Although an appropriate immune response is critical for controlling these parasites, inappropriate inflammatory reactions can also promote increased pathology. The role of immune modulatory effect of the main transcription factors and cytokines of T regulatory and Th17 cells in pathogenesis of leishmaniasis chronicity was investigated in this study. The gene expression of interleukin-10 (IL-10), transforming growth factor-ß (TGF-ß1), forkhead box P3 (Foxp3), interleukin-17(IL-17A) and retinoic acid-related orphan receptor gamma t (ROrC) was assessed in peripheral blood mononuclear cells of eighty blood samples from cutaneous leishmaniasis (CL) patients with usual lesions (n = 31), lupoid lesions (n = 29) and healthy volunteers (n = 20). Quantitative relative real-time PCR (qRT-PCR) was performed using the Taqman and Sybergreen methods for expression of target genes. Expression of Foxp3 (P = .013), IL-10 (P < .001) and IL-17A (P < .001) was significantly higher in lupoid patient compare to the nonlupoid group. Expression of Foxp3 (P < .001), IL-10 (P < .001) and IL-17A (P = .033) was significantly more in nonlupoid subjects than in healthy volunteers, except for RORγt. These findings suggest that Foxp3+ cells, IL-10 and IL-17 play important roles in the immunopathogenesis of CL and that these roles differ depending on the causal leishmania species and different body compartments.

Aberrant methylation of APC and RARß2 genes in breast cancer patients.

Changes in the status of DNA methylation are one of the most common molecular alterations in human neoplasia. We aimed to identify epigenetic molecular markers in serum for early detection of breast cancer. Authors analyzed retrospectively the methylation status of RARß2 and APC genes in serum samples from 121 breast cancer patients, 79 patients with benign breast diseases, and 66 healthy volunteers using methylation-specific PCR. The methylated APC and RARß2 were significantly higher in breast cancer patients (93.4%, 95.6%) than benign (7.8%, 14.5%) but not detected in healthy volunteers (0%) at (P < 0.0001). Both methylated genes showed no significant difference among clinicopathological factors apart from triple negative breast cancer patients as all of them (χ(2) = 7.4, P = 0.007) reported to be methylated RARß2 genes. Both methylated genes were detected in all grades and stages. Both sensitivities and specificities of the methylated genes for breast cancer detection were superior to traditional tumor markers in detection of breast cancer, early stage, low grade tumors, and triple negative breast cancer patients. Thus methylated APC and RARß2 genes might be valuable serum-based molecular markers for early detection of breast cancer.

MIRA analysis of RARß2 gene methylation in DNA circulating in the blood in lung cancer.

Analysis of DNA epigenetic mutations in the blood circulating DNA is a prospective trend for creation of noninvasive methods for the diagnosis and treatment efficiency monitoring in cancer. The methylation status of target genes in circulating DNA was evaluated by methods based on preliminary bisulfite conversion of DNA. We used a different approach based on selection of hypermethylated sequences of circulating DNA by means of DNA-methyl-binding protein (methylated CpG island recovery assay, MIRA). Methylation was evaluated for RARß2 tumor suppression gene in circulating DNA in lung cancer and a trend was detected to higher methylation of this gene in the patients in comparison with healthy donors.

Retinoic acid receptor alpha: One of plasma biomarkers associated with exacerbation of chronic obstructive pulmonary disease.

BACKGROUND: Exacerbation of COPD is a major risk factor for bad prognosis of COPD. A few plasma proteins have been discovered to associate with hospital admission due to exacerbation up to date. We tried to find new plasma biomarkers to predict the exacerbation of COPD. METHODS: We examined the plasma of normal control (n = 8) and COPD stable (n = 8) and exacerbation (n = 8) using 2-Dimentional Electrophoresis. The differentially expressed protein spots were identified by MALDI-TOF. ELISA were performed for quantitative measurement of RARα in plasma from normal control (n = 37) and COPD (n = 35). RESULTS: 17 proteins were differentially expressed in plasma between stable and exacerbation state in the subjects with COPD. Identification using MALDI-TOF showed that retinoic acid receptor alpha, ninein, isoform CRA_a, alpha-1 antitrypsin, fibrinogen gamma, tyrosyl-DNA phosphodiesterase 2, and T cell receptor delta chain were increased in exacerbation of COPD, while fibrin beta, Crystal Structure Of An Autoimmune Complex Between A Human Igm RF* And Igg1 Fc, transferrin, serpin peptidase inhibitor member 6, complement factor B preproprotein, Chain B, Crig Bound To C3c, and WD repeat-containing protein 1 isoform 1 were decreased. Quantitative measurement showed that RARα plasma levels significantly increased in exacerbation state compared to stable state of COPD (n = 14). In the plasma of stable state, the COPD subjects (n = 14) having more than 0.4 time/yr of admission had very high levels of RAR alpha protein and those (n = 11) having less than 0.4 times/yr of admission had the intermediate levels compared to those having no exacerbation (n = 10). ROC analysis of RAR alpha levels to frequency of admission showed an area under the curve of 0.844. A cut-off of 0.154 ng/ml of RAR alpha predicted hospital admission with a sensitivity of 71.4% and a specificity of 92.8%. CONCLUSION: The proteomic analysis of plasma indicates that alteration of several proteins may be associated with admission of COPD. Among them, plasma RAR alpha level may predict hospital admission with a sensitivity of 71.4% and a specificity of 92.8%.

The association of retinoic acid receptor beta2(RARß2) methylation status and prostate cancer risk: a systematic review and meta-analysis.

The retinoic acid receptor beta2(RARß2) is a type of nuclear receptor that is activated by both all-trans retinoic acid and 9-cis retinoic acid, which has been shown to function as a tumor suppressor gene in different types of human tumors. Previous reports demonstrated that the frequency of RARß2 methylation was significantly higher in prostate cancer patients compared with controls, but the relationship between RARß2 promoter methylation and pathological stage or Gleason score of prostate cancer remained controversial. Therefore, a meta-analysis of published studies investigating the effects of RARß2 methylation status in prostate cancer occurrence and association with both pathological stage and Gleason score in prostate cancer was performed in the study. A total of 12 eligible studies involving 777 cases and 404 controls were included in the pooled analyses. Under the random-effects model, the pooled OR of RARß2 methylation in prostate cancer patients, compared to non-cancer controls, was 17.62 with 95%CI = 6.30-49.28. The pooled OR with the fixed-effects model of pathological stage in RASSF1A methylated patients, compared to unmethylated patients, was 0.67 (95%CI = 0.40-1.09) and the pooled OR of low-GS in RARß2 methylated patients by the random-effect model, compared to high-GS RARß2 methylated patients, was 0.54 (95%CI = 0.28-1.04). This study showed that RARß2 might be a potential biomarker in prostate cancer prevention and diagnosis. The detection of RARß2 methylation in urine or serum is a potential non-invasive diagnostic tool in prostate cancer. The present findings also require confirmation through adequately designed prospective studies.

[DNA methylation status of RARß2 and p16(INK4α) in peripheral blood and tumor tissue in patients with esophageal squamous cell carcinoma].

OBJECTIVE: To study the methylation status of retinoic acid receptor ß2 (RARß2) and p16(INK4α) genes in peripheral blood and tumor tissues and the perioperative dynamic changes of free RARß2 and p16(INK4α) in the peripheral blood, and to investigate the relationship between RARß2 and p16(INK4α) methylation in peripheral blood and clinicopathological characteristics of esophageal squamous cell carcinoma (ESCC) and their value in evaluating the completeness of surgical resection. METHODS: Real-time methylation specific polymerase chain reaction (real-time MSP) technique was used to detect the methylation status of RARß2 and p16(INK4α) in tumor tissue, adjacent normal tissue and peripheral blood perioperatively in 76 cases of ESCC. Sixty age-matched healthy volunteers were randomly selected as a control. RESULTS: RARß2 and p16(INK4α) hypermethylation presented in both tumor tissue [72.4% (55/76) and 86.8% (66/76)] and peripheral blood [63.2% (48/76) and 71.1% (54/76)] in the ESCC patients, showing a good agreement between them. RARß2 and p16(INK4α) hypermethylation was significantly related with pathological stage, lymph node metastasis, and invasion of nerves and vessels (P < 0.05). The DNA methylation rate in peripheral blood was increasing first and then decreasing in the preoperative, intraoperative and postoperative periods. Moreover, the RARß2 methylation in peripheral blood was shown to be significantly associated with family history of cancer (P = 0.023). CONCLUSION: RARß2 and p16(INK4α) methylation in the peripheral blood in ESCC patients may reflect the tumor-bearing status in the body, and may serve as a valuable marker in assessment of the degree of completeness of surgical resection in ESCC patients.

Detection of aberrant promoter methylation of GSTP1, RASSF1A, and RARß2 in serum DNA of patients with breast cancer by a newly established one-step methylation-specific PCR assay.

Aberrant promoter methylation of genes is a common molecular event in breast cancer. Thus, DNA methylation analysis is expected to be a new tool for cancer diagnosis. In this article, we have established a new, high-performance DNA methylation assay, the one-step methylation-specific polymerase chain reaction (OS-MSP) assay, which is optimized for analyzing gene methylation in serum DNA. The OS-MSP assay is designed to detect aberrant promoter methylation of GSTP1, RASSF1A, and RARß2 genes in serum DNA. Moreover, two quality control markers were designed for monitoring the bisulfite conversion efficiency and measuring the DNA content in the serum. Serum samples were collected from patients with primary (n = 101, stages I-III) and metastatic breast cancers (n = 58) as well as from healthy controls (n = 87). If methylation of at least one of the three genes was observed, the OS-MSP assay was considered positive. The sensitivity of this assay was significantly higher than that of the assay involving conventional tumor markers (CEA and/or CA15-3) for stages I (24 vs. 8%) and II (26 vs. 8%) breast cancer and similar to that of the assay involving the conventional tumor markers for stage III (18 vs. 19%) and metastatic breast cancers (55 vs. 59%). The results of the OS-MSP assay and those of the assay involving CEA and/or CA15-3 seemed to compensate for each other because sensitivity of these assays increased to 78% when used in combination for metastatic breast cancer. In conclusion, we have developed a new OS-MSP assay with improved sensitivity and convenience; thus, this assay is more suitable for detecting aberrant promoter methylation in serum DNA. Moreover, the combination of the OS-MSP assay and the assay involving CEA and/or CA15-3 is promising for enhancing the sensitivity of diagnosis of metastatic breast cancer.

Retinoic acid receptor ß2 (RARß2): nonivasive biomarker for distinguishing malignant versus benign prostate lesions from bodily fluids.

UNLABELLED: Alterations in the methylation patterns of promoter CpG islands have been associated with the transcriptional inhibition of genes in many human cancers, including prostate cancer (PCa). OBJECTIVES: The aim of our study was to evaluate the diagnostic value of aberrant promoter hypermethylation of retinoic acid receptor ß2 (RARß2) gene in serum DNA samples from patients with the diagnosis of PCa and benign prostatic hyperplasia (BPH), as a new epigenetic biomarker in distinguishing between malignant and non-malignant lesions. MATERIALS AND METHODS: Aberrant promoter hypermethylation was investigated in genomic DNA isolated from the serum of 91 patients diagnosed with of PCa and 94 with BPH (control subjects). In order to evaluate the methylation status of the RARß2 gene we used the quantitative methylation-specific PCR (QMSP) method. RESULTS: Promoter hypermethylation of RARß2 gene was detected in serum samples from 89 of 91 (92.86%) patients with PCa, and in 10 of the 94 (10.7%) patients with BPH. CONCLUSIONS: RARß2 represents a promising molecular biomarker which may be used in discriminating between malignant and benign prostatic diseases by noninvasive methods.

RARß2 gene methylation level in the circulating DNA from blood of patients with lung cancer.

Alterations in the patterns of DNA methylation are among the earliest and most common events in tumorigenesis. Epigenetic changes were shown to be detectable in DNA, circulating in blood (cirDNA) of cancer patients, indicating the resources to create the minimally invasive diagnostic tests based on tumor-specific DNA markers. RARß2 methylation level was significantly increased in plasma cirDNA and cell surface-bound cirDNA (csb-cirDNA) from patients with non-small cell lung cancer compared with healthy individuals (7620 and 1083 copies/ml in the csb fractions, 3589 and 1068 copies/ml in the blood plasma; P=0.003 and 0.001). The cell-bound-to-cell-free RARß2 methylation ratio was found to be elevated in patients with non-small cell lung cancer compared with control (2.12 and 1.01, respectively; P=0.023). RARß2 methylation level in csb-cirDNA and plasma cirDNA was higher in stage III patients compared with stage I-II patients (P=0.02 and 0.03). In the subgroup of patients with squamous cell carcinoma, RARß2 methylation level in the cbs-cirDNA was higher compared with patients with adenocarcinoma (P=0.04). Epigenetic alterations of tumor suppressor gene RARß2 in the total cirDNA (plasma cirDNA and csb-cirDNA) were found to be associated with lung cancer progression. The data obtained indicate that cirDNA-based testing provides a valuable source for subsequent verification of methylated DNA markers for lung cancer diagnostics and prognosis.

Comparative endocrine disruptive effects of contaminants in ringed seals (Phoca hispida) from Svalbard and the Baltic Sea.

We investigated variables related to thyroid, vitamin A and calcitriol homeostasis, immune function and tumour development in ringed seals (Phoca hispida) from the polluted Baltic Sea and a less polluted reference location at Svalbard, Norway. We also examined the relationships between the biological variables and the concentrations of persistent organic pollutants (POPs) and their hydroxylated (OH) metabolites. Our data show higher plasma concentrations of free triiodothyronine (T3), and ratios of free and total T3 in Baltic seals as compared to Svalbard seals. Baltic seals had also higher hepatic mRNA expressions of deiodinase-I, thyroid hormone receptor beta, retinoic acid receptor alpha, growth hormone receptor and interleukin-1beta compared to Svalbard seals. Levels of plasma retinol were lower in the Baltic seals as compared to Svalbard seals. No geographical difference was observed for other thyroid hormone levels and hepatic retinoid levels. Ratios of free and total T3 were positively correlated to OH-POPs in plasma. The results of the present study suggest that endocrine homeostasis may be affected by contaminant and metabolite exposure in the Baltic ringed seals with respect to circulating hormones and retinol and hepatic mRNA expressions. In addition, OH-POPs may putatively produce the disruption of thyroid hormone transport in plasma.

Dysregulation of retinoid transporters expression in body fluids of schizophrenia patients.

This study aims to find the biomarkers or associated proteins in body fluids of schizophrenia patients so that we can further understand the etiology of schizophrenia. We applied proteomic technologies combining two-dimensional electrophoresis with Coomassie blue staining and mass spectrometry and identified a procedure for the clinical screening of disease-influenced body fluid proteins in two sets of samples, plasma from 19 schizophrenia patients and cerebrospinal fluid (CSF) from 35 drug-treated schizophrenic patients and 36 healthy controls. The expression of transthyretin (TTR) tetramer increased significantly in plasma of schizophrenic patients after a valid 2 months in-hospital antipsychotic treatment. Conversely, the expression of the TTR tetramer and apolipoprotein E (ApoE) was down-regulated by up to 1.68 and 3.62 times, respectively, in the CSF of schizophrenia patients compared to that of normal controls, which has not been reported previously. Considering that the TTR tetramer and ApoE are both retinoid transporters, retinoid dysfunction might be involved in the pathology of schizophrenia.

Comparison of serum aberrant methylation and conventional tumor markers in gastric cancer patients.

BACKGROUND/AIMS: This study was designed to compare a methylation-specific polymerase chain reaction (MSP) assay for three genes [p16, E-cadherin, and retinoic acid receptor beta (RARbeta)] and conventional serum tumor markers using blood samples from gastric cancer patients. METHODOLOGY: Preoperative blood samples obtained from 63 consecutive patients with gastric cancer were subjected to MSP and conventional serum marker assays. RESULTS: MSP assay detected hypermethylation of p16 in 17 patients (27%), E-cadherin in 15 patients (24%), and RARbeta in 11 patients (17%). Altogether, 32 patients (51%) showed hypermethylation in serum samples. By contrast, only 21 (33%) patients exhibited elevations of serum carcinoembryonic antigen or carbohydrate antigen 19-9. There was no correlation between MSP results and conventional tumor markers. CONCLUSIONS: The detection rate for MSP was higher than that of conventional tumor markers in serum of gastric cancer patients. Both assays can serve as complementary markers that allow for selection of cases requiring more intensive screening or aggressive postoperative treatment.

Aging affects the retinoic acid and the triiodothyronine nuclear receptor mRNA expression in human peripheral blood mononuclear cells.

BACKGROUND: Inadequate retinoid status has often been described as occurring with aging. Moreover, subclinical hypothyroid status has also been evoked in the elderly. Several studies performed in animals have described the crucial incidence of age-related hypo-functioning of retinoid and thyroid signalling pathways, particularly in the brain. OBJECTIVE: The aim of the present study was to clarify whether aging modifies retinoid and thyroid signalling in humans. METHODS: Using real-time RT-PCR the relative amount of mRNA of the retinoid (RARalpha, RARgamma and RXRalpha) and thyroid (TRalpha and TRbeta) nuclear receptors in peripheral blood mononuclear cells (PBMC) of young (24-57 years old, n = 22) compared with elderly (69-90 years old, n = 24) healthy subjects was quantitated. Classical plasma parameters used to characterize the retinoid and thyroid status - retinol (ROH), retinol-binding protein (RBP), free triiodothyronine (FT3) and thyroxine (FT4), thyroid-stimulating hormone (TSH) and transthyretin (TTR) - were also assessed. RESULTS: RARgamma expression was significantly decreased in elderly versus young subjects while no modification of the retinoid-related plasma parameters ROH and RBP were emphasized by aging. Concerning thyroid criteria, the elderly exhibited an increase in TSH concentration (+39%) without significant modifications of FT3 and FT4, which indicated an age-related sub-clinical hypothyroidism. Concurrently, the amount of TR mRNA (alpha as well as beta subtypes) was significantly decreased in the elderly. CONCLUSION: These data constitute the first evidence of an age-related hypo-activation of the retinoid and thyroid nuclear pathways in PBMC. Further study of the possible association between the expression of the retinoid and thyroid nuclear receptors and age-related cognitive alterations in humans would be interesting.

Characterization of human circulating TIG2 as a ligand for the orphan receptor ChemR23.

The orphan receptor ChemR23 is a G-protein coupled receptor (GPCR) with homology to neuropeptide and chemoattractant receptors. Tazarotene, a synthetic retinoid activating retinoic acid receptor (RAR), up-regulates tazarotene-induced gene-2 (TIG2). The function and molecular target of this protein are now described. By means of reverse pharmacology screening using a peptide library generated from human hemofiltrate, we have isolated and identified TIG2 as the natural ligand of ChemR23 and report the specific molecular form of the bioactive, circulating TIG2, representing the amino-acid residues 21 to 154 of the 163 amino acid-containing prepropeptide. Based on the expression pattern of ChemR23 and TIG2, the physiological role in bone development, immune and inflammatory responses and the maintenance of skin is now being investigated.

Hypogonadotropic hypogonadism as a presenting feature of late-onset X-linked adrenal hypoplasia congenita.

Mutations in the orphan nuclear receptor DAX-1 cause X-linked adrenal hypoplasia congenita. Affected boys usually present with primary adrenal failure in early infancy or childhood. Impaired sexual development because of hypogonadotropic hypogonadism becomes apparent at the time of puberty. We report adult-onset adrenal hypoplasia congenita in a patient who presented with hypogonadism at 28 yr of age. Although he had no clinical evidence of adrenal dysfunction, compensated primary adrenal failure was diagnosed by biochemical testing. Semen analysis showed azoospermia, and he did not achieve fertility after 8 months of treatment with gonadotropins. A novel Y380D DAX-1 missense mutation, which causes partial loss of function in transient gene expression assays, was found in this patient. This case demonstrates that partial loss-of-function mutations in DAX1 can present with hypogonadotropic hypogonadism and covert adrenal failure in adulthood. Further, an important role for DAX-1 in spermatogenesis in humans is confirmed, supporting findings in the Dax1 (Ahch) knockout mouse.

Regulation of cellular retinoic acid binding protein (CRABP II) during human monocyte differentiation in vitro.

Cellular retinoic acid binding proteins (CRABP) are low molecular weight proteins whose precise function remains unknown. They bind retinoids and may thereby modulate the intracellular steady-state concentration of retinoids. Whereas CRABP I is ubiquitously expressed, CRABP II is mainly detected in various cell types of the skin. By representative difference analysis we found that CRABP II is also strongly expressed in human monocyte-derived macrophages (MAC) but not in freshly isolated monocytes (MO). The CRABP II mRNA was gradually upregulated during differentiation from MO to MAC in the presence of 2% serum. Adherence, which is important for MO differentiation, induced CRABP II expression, but the addition of 10(-7) M retinoic acid inhibited the upregulation of CRABP II expression during MO/MAC differentiation. As MO can differentiate along the classical pathway not only to MAC but also to dendritic cells we analyzed the expression of CRABP II in MO-derived dendritic cells cultured with 10% FCS, IL-4, and GM-CSF. In contrast to MAC, MO-derived dendritic cells showed an extremely low expression of CRABP II. From these results we conclude (1) that the availability and the metabolism of retinoids may be different in MAC compared to MO and dendritic cells and (2) that this may influence differentiation and activation of those cells.