Peptidyl-prolyl Cis-trans Isomerase A Research Articles

NQO1 Triggers Neutrophil Recruitment and NET formation to Drive Lung Metastasis of Invasive Breast Cancer.

Metastasis to the lungs is a leading cause of death for breast cancer patients. Therefore, effective therapies are urgently needed to prevent and treat breast cancer lung metastasis In this study, we uncovered a mechanism by which NAD(P)H:quinone oxidoreductase 1 (NQO1) orchestrates lung metastasis. NQO1 stabilized and upregulated peptidyl-prolyl cis-trans isomerase A (PPIA), a chaperone that regulates protein conformation and activity, by preventing its oxidation at a critical cysteine residue C161. PPIA subsequently activated CD147, a membrane protein that facilitates cell invasion. Moreover, NQO1-induced secretion of PPIA modulated the immune landscape of both primary and lung metastatic sites. Secreted PPIA engaged CD147 on neutrophils and triggered the release of neutrophil extracellular traps (NET) and neutrophil elastase, which enhanced tumor progression, invasiveness and lung colonization. Pharmacological targeting of PPIA effectively inhibited NQO1-mediated breast cancer lung metastasis. These findings reveal a previously unrecognized NQO1-PPIA-CD147-NET axis that drives breast cancer lung metastasis. Inhibiting this axis is a potential therapeutic strategy to limit lung metastasis in breast cancer patients.

Data-Independent Acquisition-Based Serum Proteomic Profiling of Adult Moyamoya Disease Patients Reveals the Potential Pathogenesis of Vascular Changes.

Moyamoya disease (MMD) is a chronic cerebrovascular disease with unknown etiology. The pathogenesis of vascular changes remains unclear. Ischemic and hemorrhagic adult MMD patients and healthy volunteers were enrolled to collect serum for data-independent acquisition (DIA)-based proteomic analysis and ELISA validation. DIA serum proteomic revealed that apolipoprotein C-I (APOC1), apolipoprotein D (APOD), and apolipoprotein A-IV (APOA4) were decreased. The reductases glutathione S-transferase omega-1 (GSTO1) and peptidyl-prolyl cis-trans isomerase A (PPIA) were upregulated, and ADAMTS-like protein 4 (ADAMTSL4) was downregulated in both ischemic and hemorrhagic MMD. Afamin (AFM) and transforming growth factor-beta-induced protein ig-h3 (TGFBI) increased in ischemic patients but decreased in hemorrhagic patients. Serum ELISA results confirmed that APOA4, APOC1, and APOD were decreased compared to controls. Then, we retrospectively analyzed biochemical indexes of 200 MMD patients. A total of 54 enrolled MMD patients showed decreased total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-c). APOA4, APOC1, and APOD were vital factors in the HDL decrease in MMD patients. Lipoprotein dysfunction in MMD patients is involved in MMD. Intimal thickening by enhanced adhesion, middle layer vascular smooth muscle cell migration, and decreased lipid antioxidant function represented by HDL are potential pathogeneses of vascular changes in MMD.

Defective cyclophilin A induces TDP-43 proteinopathy: implications for amyotrophic lateral sclerosis and frontotemporal dementia.

Aggregation and cytoplasmic mislocalization of TDP-43 are pathological hallmarks of amyotrophic lateral sclerosis and frontotemporal dementia spectrum. However, the molecular mechanism by which TDP-43 aggregates form and cause neurodegeneration remains poorly understood. Cyclophilin A, also known as peptidyl-prolyl cis-trans isomerase A (PPIA), is a foldase and molecular chaperone. We previously found that PPIA interacts with TDP-43 and governs some of its functions, and its deficiency accelerates disease in a mouse model of amyotrophic lateral sclerosis.Here we characterized PPIA knock-out mice throughout their lifespan and found that they develop a neurodegenerative disease with key behavioural features of frontotemporal dementia, marked TDP-43 pathology and late-onset motor dysfunction.In the mouse brain, deficient PPIA induces mislocalization and aggregation of the GTP-binding nuclear protein Ran, a PPIA interactor and a master regulator of nucleocytoplasmic transport, also for TDP-43. Moreover, in absence of PPIA, TDP-43 autoregulation is perturbed and TDP-43 and proteins involved in synaptic function are downregulated, leading to impairment of synaptic plasticity. Finally, we found that PPIA was downregulated in several patients with amyotrophic lateral sclerosis and amyotrophic lateral sclerosis-frontotemporal dementia, and identified a PPIA loss-of-function mutation in a patient with sporadic amyotrophic lateral sclerosis . The mutant PPIA has low stability, altered structure and impaired interaction with TDP-43.These findings strongly implicate that defective PPIA function causes TDP-43 mislocalization and dysfunction and should be considered in future therapeutic approaches.

Serum Analysis of Women with Early-Stage Breast Cancer Using a Mini-Array of Tumor-Associated Antigens.

Background: Several studies have shown that patients with cancer have antibodies in serum that react with cellular autoantigens, known as Tumor-Associated Antigens (TAA). The present work aimed to determine whether a mini-array comprising four recombinant TAA increases the detection of specific serum antibodies for the diagnosis of early-stage breast cancer. Methods: The mini-array included Alpha 1-AntiTrypsin (A1AT), TriosePhosphate Isomerase 1 (TPI1), Peptidyl-Prolyl cis-trans Isomerase A (PPIA), and PeroxiReDoXin 2 (PRDX2) full-length recombinant proteins. The proteins were produced after gene cloning, expression, and purification, and were verified by Western blot assays. Then, Dot-Blot was performed to find antibodies against the four TAA in 12 sera from women with early-stage breast cancer (stage II) and 12 sera from healthy women. Results: Antibody detection against individual TAA in early-stage breast cancer sera ranged from 58.3% to 83.3%. However, evaluation of the four TAA showed that there was a positive antibody reaction reaching a sensitivity of 100% and a specificity of 85% in early-stage breast cancer, suggesting that this mini-array must be evaluated as a clinical diagnostic tool for early-stage breast cancer in a larger sample size. Conclusion: Our results suggest that TAA mini-arrays may provide a promising and powerful method for improving the detection of breast cancer in Mexican women.

The Secretome Analysis of Activated Human Renal Fibroblasts Revealed Beneficial Effect of the Modulation of the Secreted Peptidyl-Prolyl Cis-Trans Isomerase A in Kidney Fibrosis.

The secretome is an important mediator in the permanent process of reciprocity between cells and their environment. Components of secretome are involved in a large number of physiological mechanisms including differentiation, migration, and extracellular matrix modulation. Alteration in secretome composition may therefore trigger cell transformation, inflammation, and diseases. In the kidney, aberrant protein secretion plays a central role in cell activation and transition and in promoting renal fibrosis onset and progression. Using comparative proteomic analyses, we investigated in the present study the impact of cell transition on renal fibroblast cells secretome. Human renal cell lines were stimulated with profibrotic hormones and cytokines, and alterations in secretome were investigated using proteomic approaches. We identified protein signatures specific for the fibrotic phenotype and investigated the impact of modeling secretome proteins on extra cellular matrix accumulation. The secretion of peptidyl-prolyl cis-trans isomerase A (PPIA) was demonstrated to be associated with fibrosis phenotype. We showed that the in-vitro inhibition of PPIA with ciclosporin A (CsA) resulted in downregulation of PPIA and fibronectin (FN1) expression and significantly reduced their secretion. Knockdown studies of PPIA in a three-dimensional (3D) cell culture model significantly impaired the secretion and accumulation of the extracellular matrix (ECM), suggesting a positive therapeutic effect on renal fibrosis progression.

Proteomic changes by radio-mitigative thrombopoietin receptor agonist romiplostim in the blood of mice exposed to lethal total-body irradiation

Purpose The thrombopoietin receptor agonist romiplostim (RP) is a therapeutic agent for immune thrombocytopenia that can achieve complete survival in mice exposed to a lethal dose of ionizing radiation. The estimated mechanism of the radio-protective/mitigative effects of RP has been proposed; however, the detailed mechanism of action remains unclear. This study aimed to elucidate the mechanism of the radio-protective/mitigative effects of RP, the fluctuation of protein in the blood was analyzed by proteomics. Materials and Methods Eight-week-old female C57BL/6J mice were randomly divided into 5 groups; control at day 0, total-body irradiation (TBI) groups at day 10 and day 18, and TBI plus RP groups at day 10 and day18, consisting of 3 mice per group, and subjected to TBI with 7 Gy of 137Cs γ-rays at a dose rate of 0.74 Gy/min. RP was administered intraperitoneally to mice at a dose of 50 µg/kg once daily for 3 days starting 2 hours after TBI. On day 10 and day 18 after TBI, serum collected from each mouse was analyzed by liquid chromatography tandem mass spectrometry. Results Nine proteins were identified by proteomics methods from 269 analyzed proteins detected in mice exposed to a lethal dose of TBI: keratin, type II cytoskeletal 1 (KRT1), fructose-1, 6-bisphosphatase (FBP1), cytosolic 10-formyltetrahydrofolate dehydrogenase (ALDH1L1), peptidyl-prolyl cis-trans isomerase A (PPIA), glycine N-methyltransferase (GNMT), glutathione S-transferase Mu 1 (GSTM1), regucalcin (RGN), fructose-bisphosphate aldolase B (ALDOB) and betain–homocysteine S-methyltransferase 1 (BHMT). On the 10th day after TBI, KRT1 was significantly increased (p < 0.05) by 4.26-fold compared to the control group in the TBI group and significantly inhibited in the TBI plus RP group (p < 0.05). Similarly, the expression levels of other 8 proteins detected at 18th day after TBI were significantly increased by 4.29 to 27.44-fold in the TBI group, but significantly decreased in the TBI plus RP group compared to the TBI group, respectively. Conclusion Nine proteins were identified by proteomics methods from 269 analyzed proteins detected in mice exposed to a lethal dose of TBI. These proteins are also expected to be indicators of the damage induced by high-dose radiation.

Diagnostic and prognostic values of PBMC proteins in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease for which there are no validated biomarkers. Previous exploratory studies have identified a panel of candidate protein biomarkers in peripheral blood mononuclear cells (PBMCs) that include peptidyl-prolyl cis-trans isomerase A (PPIA), heat shock cognate protein 71 kDa (HSC70), heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2B1) and TDP-43. It has also been found that PPIA plays a key role in the assembly and dynamics of ribonucleoprotein (RNP) complexes and interacts with TDP-43. Its absence accelerates disease progression in a SOD1 mouse model of ALS, and low levels of PPIA in PBMCs are associated with early-onset ALS. However, the diagnostic and prognostic values of PPIA and the other candidate protein biomarkers have not been established. We analyzed the PBMC proteins in a well-characterized cohort of ALS patients (n=93), healthy individuals (n=104) and disease controls (n=111). We used a highly controlled sample processing procedure that implies two-step differential detergent fractionation. We found that the levels of the selected PBMC proteins in the soluble and insoluble fraction, combined, have a high discriminatory power for distinguishing ALS from controls, with PPIA, hnRNPA2B1 and TDP-43 being the proteins most closely associated with ALS. We also found a shift toward increased protein partitioning in the insoluble fraction in ALS and this correlated with a worse disease phenotype. In particular, low PPIA soluble levels were associated with six months earlier death. In conclusion, PPIA is a disease modifier with prognostic potential. PBMC proteins indicative of alterations in protein and RNA homeostasis are promising biomarkers of ALS, for diagnosis, prognosis and patient stratification.

Long non-coding RNA transcribed from pseudogene PPIAP43 is associated with radiation sensitivity of small cell lung cancer cells.

Small cell lung cancer (SCLC) is a highly lethal disease. Although radiation therapy is effective for the majority of patients with SCLC, patient sensitivity to radiation varies. The lack of biomarkers impedes advances in targeting radiation-sensitive patients. In this study, the changes in transcription patterns of SCLC cell lines were evaluated with or without 2 Gy gamma radiation. The results demonstrated that peptidyl-prolyl cis-trans isomerase A pseudogene 43 (PPIAP43) transcription was increased 2-fold in cells irradiated with 2 Gy gamma radiation compared with unirradiated cells in pre-reported radio-sensitive sensitive cell lines H69, H128, H146, H209 and H187. These cells shared 259 upregulated and 96 downregulated RNA transcripts following radiation. Pre-reported less sensitive cell lines H526, D53, D114 and D153 in which PPIAP43 was not upregulated 2-fold following irradiation with 2 Gy gamma radiation compared with unirradiated cells, shared 3 upregulated and 9 downregulated RNA transcripts. The RNA transcript of PPIAP43 was aligned with the mRNA of peptidyl-prolyl cis-trans isomerase A (PPIA) at 2 sections (3,732 to 3,917 and 5,327 to 5,657 of the PPIA gene) and the sequences were shown to be 96 and 94% similar, respectively. Therefore, PPIAP43 may act as a sponge for microRNAs which bind with the RNA of PPIA. Therefore, PPIAP43 RNA transcription may serve as a potential biomarker of radio-sensitivity of SCLC.

Peptidyl-prolyl cis-trans isomerase A – A novel biomarker of multi-episodic (recurrent) ocular toxoplasmosis

Ocular toxoplasmosis (OT) is the most common etiology of posterior uveitis. The high incidence of macular scarring associated with OT is a leading cause of visual morbidity. Serum biomarkers of the disease would aid in its diagnosis. This study sought, for the first time, to elucidate serum biomarkers for OT by mass spectrometry. Blood samples were collected from four groups of nine patients each; toxoplasmosis IgG-with no history of uveitis, non-toxoplasmosis uveitis, first episode OT, and symptomatic recurrent OT. Serum was isolated and subjected to proteomics analysis using 2-dimensional gel electrophoresis (2D-GE) and surface-enhanced laser desorption ionization mass spectrometry (SELDI-MS). Selected proteins were further separated by SDS-PAGE and sequenced using tandem MS. Results were cross-validated with a T. gondii outbreak biomarker database that occurred in Brazil. Fifty markers of OT and 46 markers of recurrent disease were discovered by SELDI-MS of which 30 and 15, respectively, were cross-validated. 2D-GE analysis yielded 57 bands, selected based on the intensity of the bands, leading to the identification of 20 proteins. Eleven of those identified candidates were also found by SELDI-MS. Four candidates were chosen for immunoblotting. One serum protein, peptidyl-prolyl cis-trans isomerase A (PPIA), was confirmed as a biomarker of multi-episodic OT by immunoblotting in patients. PPIA can identify the patient with active recurrent OT from acute OT, other forms of uveitis and other parasitic infections. A validated PPIA assay may have a role in the diagnosis of the atypical OT patient before more invasive anterior chamber or vitreous tap is performed for PCR analysis or for Goldmann-Witner coefficient calculations. Base-line PPIA levels need to be studied to understand its possible use when deciding for prophylactic antibiotic use in the immunosuppressed sero-positive patient.

AB039. Peptidyl-prolyl cis-trans isomerase A (PPIA)—a novel biomarker of multi-episodic (recurrent) ocular toxoplasmosis

AB039. Peptidyl-prolyl cis-trans isomerase A (PPIA)—a novel biomarker of multi-episodic (recurrent) ocular toxoplasmosis

Selected reaction monitoring approach for validating peptide biomarkers

We here describe a selected reaction monitoring (SRM)-based approach for the discovery and validation of peptide biomarkers for cancer. The first stage of this approach is the direct identification of candidate peptides through comparison of proteolytic peptides derived from the plasma of cancer patients or healthy individuals. Several hundred candidate peptides were identified through this method, providing challenges for choosing and validating the small number of peptides that might prove diagnostically useful. To accomplish this validation, we used 2D chromatography coupled with SRM of candidate peptides. We applied this approach, called sequential analysis of fractionated eluates by SRM (SAFE-SRM), to plasma from cancer patients and discovered two peptides encoded by the peptidyl-prolyl cis-trans isomerase A (PPIA) gene whose abundance was increased in the plasma of ovarian cancer patients. At optimal thresholds, elevated levels of at least one of these two peptides was detected in 43 (68.3%) of 63 women with ovarian cancer but in none of 50 healthy controls. In addition to providing a potential biomarker for ovarian cancer, this approach is generally applicable to the discovery of peptides characteristic of various disease states.

Selection of housekeeping genes as internal controls for quantitative RT-PCR analysis of the veined rapa whelk (Rapana venosa).

BackgroundThe veined rapa whelk Rapana venosa is an important commercial shellfish in China and quantitative real-time PCR (qRT-PCR) has become the standard method to study gene expression in R. venosa. For accurate and reliable gene expression results, qRT-PCR assays require housekeeping genes as internal controls, which display highly uniform expression in different tissues or stages of development. However, to date no studies have validated housekeeping genes in R. venosa for use as internal controls for qRT-PCR.MethodsIn this study, we selected the following 13 candidate genes for suitability as internal controls: elongation factor-1α (EF-1α), α-actin (ACT), cytochrome c oxidase subunit 1 (COX1), nicotinamide adenine dinucleotide dehydrogenase (ubiquinone) 1α subcomplex subunit 7 (NDUFA7), 60S ribosomal protein L5 (RL5), 60S ribosomal protein L28 (RL28), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), β-tubulin (TUBB), 40S ribosomal protein S25 (RS25), 40S ribosomal protein S8 (RS8), ubiquitin-conjugating enzyme E2 (UBE2), histone H3 (HH3), and peptidyl-prolyl cis-trans isomerase A (PPIA). We measured the expression levels of these 13 candidate internal controls in eight different tissues and twelve larvae developmental stages by qRT-PCR. Further analysis of the expression stability of the tested genes was performed using GeNorm and RefFinder algorithms.ResultsOf the 13 candidate genes tested, we found that EF-1α was the most stable internal control gene in almost all adult tissue samples investigated with RL5 and RL28 as secondary choices. For the normalization of a single specific tissue, we suggested that EF-1α and NDUFA7 are the best combination in gonad, as well as COX1 and RL28 for intestine, EF-1α and RL5 for kidney, EF-1α and COX1 for gill, EF-1α and RL28 for Leiblein and mantle, EF-1α, RL5, and NDUFA7 for liver, GAPDH, PPIA, and RL28 for hemocyte. From a developmental perspective, we found that RL28 was the most stable gene in all developmental stages measured, and COX1 and RL5 were appropriate secondary choices. For the specific developmental stage, we recommended the following combination for normalization, PPIA, RS25, and RL28 for stage 1, RL5 and RL28 for stage 2 and 5, RL28 and NDUFA7 for stage 3, and PPIA and TUBB for stage 4.DiscussionOur results are instrumental for the selection of appropriately validated housekeeping genes for use as internal controls for gene expression studies in adult tissues or larval development of R. venosa in the future.

Targeting Extracellular Cyclophilin A Reduces Neuroinflammation and Extends Survival in a Mouse Model of Amyotrophic Lateral Sclerosis.

Neuroinflammation is a major hallmark of amyotrophic lateral sclerosis (ALS), which is currently untreatable. Several anti-inflammatory compounds have been evaluated in patients and in animal models of ALS, but have been proven disappointing in part because effective targets have not yet been identified. Cyclophilin A, also known as peptidylprolyl cis-/trans-isomerase A (PPIA), as a foldase is beneficial intracellularly, but extracellularly has detrimental functions. We found that extracellular PPIA is a mediator of neuroinflammation in ALS. It is a major inducer of matrix metalloproteinase 9 and is selectively toxic for motor neurons. High levels of PPIA were found in the CSF of SOD1G93A mice and rats and sporadic ALS patients, suggesting that our findings may be relevant for familial and sporadic cases. A specific inhibitor of extracellular PPIA, MM218, given at symptom onset, rescued motor neurons and extended survival in the SOD1G93A mouse model of familial ALS by 11 d. The treatment resulted in the polarization of glia toward a prohealing phenotype associated with reduced NF-κB activation, proinflammatory markers, endoplasmic reticulum stress, and insoluble phosphorylated TDP-43. Our results indicates that extracellular PPIA is a promising druggable target for ALS and support further studies to develop a therapy to arrest or slow the progression of the disease in patients.SIGNIFICANCE STATEMENT We provide evidence that extracellular cyclophilin A, also known as peptidylprolyl cis-/trans-isomerase A (PPIA), is a mediator of the neuroinflammatory reaction in amyotrophic lateral sclerosis (ALS) and is toxic for motor neurons. Supporting this, a specific extracellular PPIA inhibitor reduced neuroinflammation, rescued motor neurons, and extended survival in the SOD1G93A mouse model of familial ALS. Our findings suggest selective pharmacological inhibition of extracellular PPIA as a novel therapeutic strategy, not only for SOD1-linked ALS, but possibly also for sporadic ALS. This approach aims to address the neuroinflammatory reaction that is a major hallmark of ALS. However, given the complexity of the disease, a combination of therapeutic approaches may be necessary.

Comparative proteomic analysis of paclitaxel resistance-related proteins in human breast cancer cell lines.

Paclitaxel is widely used to treat various cancers; however, resistance to this drug is a major obstacle to breast cancer chemotherapy. To identify the proteins involved in paclitaxel resistance, the present study compared the proteomes of MCF-7 human breast cancer cells and its paclitaxel-resistant subclone MCF-7/PTX. Using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry, 11 upregulated and 12 downregulated proteins were identified in MCF-7/PTX cells compared with the parental cell line. These 23 proteins were functionally classified as stress-induced chaperones, metabolic enzymes and cytoskeletal proteins. The anti-apoptotic proteins, stress-70 protein, 78-kD glucose-regulated protein, peptidyl-prolyl cis-trans isomerase A (PPIA) and heterogeneous nuclear ribonucleoprotein H3, were also upregulated in MCF-7/PTX cells. Notably, knockdown of the stress-response chaperone PPIA using small interfering RNA in MCF-7/PTX cells restored their sensitivity to paclitaxel. These findings indicated that PPIA may have an important role in paclitaxel resistance in MCF-7/PTX cells.

PPIA is a novel adipogenic factor implicated in obesity.

To assess the role of peptidyl-prolyl cis/trans isomerase a (PPIA) in adipogenesis and obesity. Fat mass and adipocyte sizes of PPIA-/- and wild-type mice were compared. The role of PPIA in adipocyte differentiation of 3T3L1 and MEFs cells was analyzed by gene silencing and overexpression. The roles of PPIA in obesity were observed on a high-fat diet obesity model and a gestational diabetes obesity model. PPIA-/- mice had significantly less fat than PPIA+/+ mice. The adipocyte size of PPIA-/- mice was significantly smaller than wild type. Silencing PPIA in 3T3L1 cells significantly impaired its adipocyte differentiation ability. Similarly, MEFs from PPIA-/- mice differentiated less than wild type, while their differentiation ability was restored by PPIA overexpression. PPIA-silenced 3T3L1 cells had significantly lower expression of PPARG, C/EBPA, and C/EBPB at late stage of adipocyte differentiation, which was the same in PPIA-/- MEFs. When fed a high-fat diet, PPIA-/- mice gained significantly less weight than wild type, accompanied by reduced PPARG, C/EBPA, and C/EBPB expression. PPIA expression was significantly higher in adipose tissue of gestational diabetes rat offspring, which had higher inguinal fat/body weight ratios than normal rat offspring. PPIA was a novel adipogenic factor important in obesity.

Comparative mitochondrial proteomic analysis of hepatocellular carcinoma from patients

To define mitochondrial protein markers related to liver cancer. Mitochondrial subproteomes of 20 patient-derived liver carcinoma and tumor-free control tissues were performed by 2DE coupled with MALDI-TOF/TOF. The altered patterns of three identified proteins were validated by Western blot and immunohistochemistry. The results showed that compared with tumor-free control samples, nine proteins were downregulated and six proteins were upregulated in carcinoma samples. The increased expression of Arg1 mRNA and protein was validated by Western blot, Q-RT-PCR, paraffin tissue microarray and immunohistochemistry. Furthermore, a literature review shows that Heat shock protein 10 (Hsp10), single-stranded DNA-binding protein (SSBP1), and peptidyl-prolyl cis-trans isomerase A (PPIA), which were identified as being increased in the tumor samples in this study, may be closely related to protein folding and translation. These results show that in addition to changes in the signaling pathways, such as the Ras-Raf-MEK-ERK pathway, altered mitochondrial DNA replication and protein folding in liver cancer are also worth studying further. Collectively, these results suggest that specific mitochondrial proteins are uniquely susceptible to alterations in expression and carry implications for the investigation of their potential as therapeutic and prognostic markers. Further studies focusing on these proteins will be used to predict treatment response and reverse the apoptosis resistance.

Research for the effect of octylphenol on spermatogenesis and proteomic analysis in octylphenol-treated mice testes

OP (octylphenol), an environmental oestrogen was administered, and differentially expressed proteins were analysed in mice testes to clarify its mechanism of action in male sterility. Male Kunming suckling mice (10 days old) were subcutaneously injected with OP at a dose of 10 μg/kg per day, 50 μg/kg per day and 100 μg/kg per day as low-, medium- and high-dose groups, respectively, for 35 days. Animals in the control group received subcutaneous injections of olive oil at a dose of 10 μl/mouse per day. Serum oestradiol, testosterone, FSH (follicle stimulating hormone) and LH (luteinizing hormone) levels were measured on day 45. The left testes were removed for tissue analysis, and the right testes were analysed for differentially expressed proteins by using two-dimensional gel electrophoresis and MS. Tissue analysis showed that mice spermatogenesis was blocked at the round spermatid stage in the high-dose group, whereas no such changes were found in the medium- and low-dose groups. Higher serum oestradiol (P<0.05) and lower testosterone (P<0.05) levels were found in the medium- and high-dose groups. There was no significant difference in serum oestradiol and testosterone levels in the low-dose and control groups. No significant influence of OP was seen on serum FSH and LH levels in all OP-treated animals. The results from four differentially expressed proteins such as PPIA (peptidyl-prolyl cis-trans isomerase A), PEBP1 (phosphatidylethanolamine-binding protein1), TPI (triose-phosphate isomerase) and TCP-1 (T-complex protein 1) in the high-dose and control groups showed up-regulation of PPIA expression and down-regulation in PEBP1, TPI and TCP-1 expressions. These findings will contribute to clarify the mechanism of male sterility by environmental oestrogens.

Proteomic approach reveals novel targets for retinoic acid-mediated therapy of thyroid carcinoma

Our previous studies demonstrated that retinoic acid (RA)-induced reduction of both, the key glycolytic enzyme ENO1 and proliferation-promoting c-Myc, resulted in decreased vitality and invasiveness of the follicular thyroid carcinoma cell lines FTC-133 and FTC-238. By employing two-dimensional electrophoresis and mass spectrometry, we identified proteins affected by RA treatment. In addition to previously reported decrease in ENO1 expression, we found that RA led to significantly reduced levels of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate kinase isoenzymes M1/M2 (PKM1/M2), peptidyl-prolyl cis–trans isomerase A (PPIA), transketolase (TKT), annexin A2 (ANXA2), glutathione S-transferase P (GSTP1) and peroxiredoxin 2 (PRDX2) as compared to untreated control. The same proteins investigated on thyroid tissues were found to be significantly up-regulated in follicular, papillary and undifferentiated thyroid carcinomas when compared with goiter and adenoma tissues. These findings identify new target proteins for RA-mediated anti-tumor and re-differentiation therapies and provide novel insights into treatments for thyroid carcinoma.

Up-regulated expression of the MAT-8 gene in prostate cancer and its siRNA-mediated inhibition of expression induces a decrease in proliferation of human prostate carcinoma cells

In order to analyze differential gene expression of putative prostate tumor markers we compared the expression levels of >400 cancer-related genes using the cDNA array technique in a set of prostate tumors and matched normal prostate tissues. Up-regulated expression of mammary tumor 8 kDa protein (MAT-8), complement component C1S (C1S), ferritin heavy chain (FTH1), peptidyl-prolyl cis-trans isomerase A (PPIA), RNA-binding protein regulatory subunit DJ-1 protein (DJ-1) and vacuolar ATP synthase subunit F (ATP6V1F) was determined in prostate carcinoma and confirmed by using quantitative real-time RT-PCR analyses. Furthermore, quantitative real time RT-PCR on intact RNAs from 11 paired laser microdissected epithelial tissue samples confirmed up-regulated MAT-8 expression in 6 out of 11 prostate tumors. To determine the function of MAT-8 in vitro, human PC-3 and LNCaP prostate carcinoma cells were transfected with small interfering double-stranded RNA (siRNA) oligonucleotides against the MAT-8 gene leading to a specific down-regulation of MAT-8 expression. In addition, suppression of MAT-8 expression caused a significant decrease in cellular proliferation of both prostate cancer cell lines, whereas invasive capacity and cellular apoptosis remained unaffected. Taken together, our results indicate that the human MAT-8 gene contains the potential to serve as a prostate cancer expression marker and that MAT-8 plays an important role in cellular growth of prostate carcinomas.