Expression Levels Of GAPDH Research Articles

Abstract 3533: Effects of tyrosine kinase inhibitors imatinib, dasatinib, and nilotinib on cancer-associated fibroblast phenotypes in colorectal cancer

Abstract Background: Cancer-associated fibroblasts (CAFs) are major regulators of the immune microenvironment and therapeutic response in colorectal cancer (CRC). Neutralizing their role in modulating the immune landscape could be the key to enhancing immunotherapy success. Imatinib, dasatinib, and nilotinib are tyrosine kinase inhibitors with several kinase targets. Methods: Tissue microarrays spanning 153 patients were stained for αSMA, TAGLN, PDPN, ICAM1, and CD8. CD8 stains were quantified as number of tumor infiltrating lymphocytes per high powered field (TILs/HPF) in the epithelial compartment. All other stains were quantified by intensity on a 0-3+ scale. Scores for αSMA and TAGLN were combined into a myCAF score, and PDPN and ICAM1 into an iCAF score. myCAF gene expression signatures derived from a re-analysis of scRNA-seq data previously done by our lab were entered into the LINCS database to discover potential drugs to reverse the phenotype. Primary cancer associated fibroblasts were derived from patient tumor samples, then treated with clinically relevant concentrations of imatinib, dasatinib, or nilotinib for 96 hours. RNA was isolated and RT-qPCR was performed to quantify the myCAF genes ACTA2, COL11A1, and TAGLN, and the iCAF genes ICAM1, PDPN, IL1R1, CXCL1 and CXCL2. TGFB1 expression was also measured. Expression was normalized to untreated cells and GAPDH expression levels. Results: Cancers with high expression of myCAF markers but low expression of iCAF markers had the most CD8+ TILs (average 10.2; median 1.5; range 0-73), while cancers with low myCAF scores and high iCAF scores had the least (average 1.5; median 0; range 0-19; p < 0.01). Reversing the myCAF signature relative to iCAFs in the LINCs database revealed nilotinib as a top hit. Treatment with imatinib did not significantly alter the expression of myCAF genes (control vs. max dose: p = 0.06 for ACTA2, COL11A1 p =0.2, TAGLN p = 1), while treatment with dasatinib significantly increased these genes (ACTA2 1.4x higher, p < 0.001; COL11A1 2.6x higher, p < 0.01; TAGLN 1.5x higher, p < 0.001). Only treatment with nilotinib significantly decreased myCAF genes (ACTA2 2.2x lower, p <0.001; COL11A1 1.3x lower, p =0.05; TAGLN 1.9x lower, p < 0.01). All three drugs decreased iCAF gene CXCL1, and all but dasatinib decreased CXCL2. All three drugs significantly decreased TGFB1, a potential functional marker for altering myCAF phenotype (dasatinib 1.1x lower, p = 0.1; imatinib 1.6x lower, p < 0.001; nilotinib 1.5x lower, p < 0.05). Conclusions: myCAFs may be major actors in immune exclusion in the microenvironment, and the reversal of the myCAF phenotype may be a target for treatment with immunotherapy. Nilotinib, but not imatinib or dasatinib, is effective at decreasing expression of myCAF genes. Further research is warranted into the mechanisms of this drug on altering expression and whether these trends continue in vivo. Citation Format: Katherine Anne Johnson, Anna L. Lippert, Sean G. Kraus, Grace E. McGrath, Philip B. Emmerich, Cheri A. Pasch, Linda Clipson, Kristina A. Matkowskyj, Wei Zhang, Dustin A. Deming. Effects of tyrosine kinase inhibitors imatinib, dasatinib, and nilotinib on cancer-associated fibroblast phenotypes in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3533.

Mutual stimulatory signaling between human myogenic cells and rat cerebellar neurons.

Insight into the bidirectional signaling between primary human myogenic cells and neurons is lacking. For this purpose, human myogenic cells were derived from the semitendinosus and gracilis muscles of five healthy individuals and co‐cultured with cerebellar granule neurons from two litters of 7‐day‐old Wistar rat pups, in muscle medium or neural medium, alongside monocultures of myogenic cells or neurons. RT‐PCR was performed to determine human mRNA levels of GAPDH, Ki67, myogenin, and MUSK, and the acetylcholine receptor subtypes CHRNA1, CHRNB1, CHRNG, CHRND, and CHRNE, and rat mRNA levels of GAPDH, Fth1, Rack1, vimentin, Cdh13, and Ppp1r1a. Immunocytochemistry was used to evaluate neurite outgrowth (GAP43) in the presence and absence of myogenic cells. Co‐culture with primary neurons lead to higher myogenic cell gene expression levels of GAPDH, myogenin, MUSK, CHRNA1, CHRNG, and CHRND, compared to myogenic cells cultured alone. It appeared that neurons preferentially attached to myotubes and that neurite outgrowth was enhanced when neurons were cultured with myogenic cells compared to monoculture. In neural medium, rat mRNA levels of GAPDH, vimentin, Cdh13, and Ppp1r1a were greater in co‐culture, versus monoculture, whereas in muscle medium co‐culture lead to lower levels of Fth1, Rack1, vimentin, and Cdh13 than monoculture. These findings demonstrate mutually beneficial stimulatory signaling between rat cerebellar granule neurons and human myogenic cells, providing support for an active role for both the neuron and the muscle cell in stimulating neurite growth and myogenesis. Bidirectional muscle nerve signaling.

Development and validation of a multiplex qPCR assay for detection and relative quantification of HPV16 and HPV18 E6 and E7 oncogenes

Human papillomaviruses (HPV) play a key role in promoting human anogenital cancers. Current high-risk HPV screening or diagnosis tests involve cytological or molecular techniques mostly based on qualitative HPV DNA detection. Here, we describe the development of a rapid quantitative polymerase chain reaction (qPCR) detection test of HPV16 and HPV18 oncogenes (E6 and E7) normalized on human gene encoding GAPDH. Optimized qPCR parameters were defined, and analytical specificities were validated. The limit of detection was 101 for all genes tested. Assay performances were evaluated on clinical samples (n = 96). Concordance between the Xpert HPV assay and the triplex assay developed here was 93.44% for HPV16 and 73.58% for HPV18. HPV co-infections were detected in 15 samples. The systems developed in the present study can be used in complement to traditional HPV tests for specifically validating the presence of HPV16 and/or HPV18. It can also be used for the follow-up of patients with confirmed infection and at risk of developing lesions, through the quantification of E6 and E7 oncogene expression (mRNA) normalized on the GAPDH expression levels.

A protective effect of acetaminophen on ibuprofen-induced small intestinal damage in rats via the suppression of MMP-13

Capsule endoscopy has revealed that nonsteroidal anti-inflammatory drugs may cause damage not only to the stomach but also to the small intestine, which has become one of the most serious issues in gastroenterology. However, few studies have reported the effect of ibuprofen (IBP), which is widely prescribed worldwide, on the small intestine, and it remains unclear whether IBP can cause small intestinal damage. We have previously shown that acetaminophen (APAP), which is used as an antipyretic/analgesic drug, inhibits IBP-induced gastric damage by suppressing matrix metalloprotease-13 (MMP-13) gene expression. In this study, we investigated the ability of IBP to induce small intestinal damage and the efficacy of APAP against IBP-induced small intestinal damage in rats. Nonfasted male Sprague-Dawley rats were orally administered with IBP (200mg/kg) and then euthanized at various time points (0, 4, 8, 16, and 24h) after the administration. The small intestine, jejunum, and ileum were removed, and intestinal lesions were measured. To elucidate the efficacy of APAP against IBP-induced small intestinal damage, the rats were treated with IBP (200mg/kg) with or without APAP (200mg/kg), and small intestinal damage was evaluated 24h after the administration. Moreover, the expression levels of GAPDH, TNFα, iNOS, and MMP-13 genes were determined at various time points (8, 16, and 24h) by RT-qPCR. The oral administration of IBP induced obvious small intestinal damage, which was found to be significant at 24h (p<0.05 vs 0h, Dunnett's test). The coadministration of APAP significantly prevented IBP-induced damage (p<0.05, Student's t-test). In addition, the expression levels of TNFα and iNOS genes were significantly increased by IBP (p<0.01 and p<0.05 vs. vehicle, respectively, Tukey-Kramer test), whereas the cotreatment with APAP suppressed the increases at 8h. Moreover, compared with the vehicle, the IBP treatment significantly increased the expression level of the MMP-13 gene (p<0.01) at each time point (8, 16, and 24h, Tukey-Kramer test), whereas the APAP cotreatment significantly suppressed the increase (p<0.01 vs. IBP at 8h, p<0.05 vs. IBP at 16 and 24h, Tukey-Kramer test). This study suggested that a single administration of IBP was associated with the risk of inducing small intestinal ulcers in rats, and APAP could prevent IBP-induced small intestinal damage by suppressing the MMP-13 gene expression.

GAPDH delivers heme to soluble guanylyl cyclase

Soluble guanylyl cyclase (sGC) is a key component of NO-cGMP signaling in mammals. Although heme must bind in the sGC β1 subunit (sGCβ) for sGC to function, how heme is delivered to sGCβ remains unknown. Given that GAPDH displays properties of a heme chaperone for inducible NO synthase, here we investigated whether heme delivery to apo-sGCβ involves GAPDH. We utilized an sGCβ reporter construct, tetra-Cys sGCβ, whose heme insertion can be followed by fluorescence quenching in live cells, assessed how lowering cell GAPDH expression impacts heme delivery, and examined whether expressing WT GAPDH or a GAPDH variant defective in heme binding recovers heme delivery. We also studied interaction between GAPDH and sGCβ in cells and their complex formation and potential heme transfer using purified proteins. We found that heme delivery to apo-sGCβ correlates with cellular GAPDH expression levels and depends on the ability of GAPDH to bind intracellular heme, that apo-sGCβ associates with GAPDH in cells and dissociates when heme binds sGCβ, and that the purified GAPDH-heme complex binds to apo-sGCβ and transfers its heme to sGCβ. On the basis of these results, we propose a model where GAPDH obtains mitochondrial heme and then forms a complex with apo-sGCβ to accomplish heme delivery to sGCβ. Our findings illuminate a critical step in sGC maturation and uncover an additional mechanism that regulates its activity in health and disease.

Phenol Based RNA Isolation is the Optimum Method for Study of Gene Expression in Human Urinary Sediment

Evaluation of gene expression in urinary sediment has been considered as a promising non-invasive approach for biomarker identification of kidney diseases. Nonetheless, there are several challenges in extraction of RNA from this valuable source of biomarkers, mostly because of the factors that have influence on quality of isolated RNA such as low cellular content. Accordingly, we compared the quality of RNA from urine sediment samples that was isolated by four different methods. TRIzol reagent with basic protocol (method 1), modified procedure of TRIzol (method 2), a column-based protocol (method 3) and combination of method 1 and 3 (method 4) were applied for isolation of RNA from identical aliquots of five healthy urine samples. The quality and yield of isolated RNA were evaluated based on concentration and purity. Expression levels of GAPDH and miR-21 were studied by quantitative RT-PCR. Methods 1 and 2 showed the highest RNA yield while no difference in purity of RNA in different methods was noticed. Quantitative RT-PCR findings indicated that Ct values in samples of method 1 had the lowest level. Although higher concentrations of RNA were isolated by method 2, the declined Ct values in this method might indicate degradation of isolated RNA. Column based protocols (method 3 and 4) were failed to show significant recovery of RNA. It seems that isolation procedure using TRIzol, as a phenol based method, is the most efficient, robust and reliable procedure for RNA isolation from urinary sediment cells.

The influence of direct and indirect fibroblast cell contact on human myogenic cell behavior and gene expression in vitro.

Underpinning skeletal muscle plasticity is the interplay between many cell types, of which fibroblasts are emerging as potent players, both negatively in the development of fibrosis but also positively in stimulating muscle repair through enhancing myogenesis. The mechanisms behind this interaction however remain unknown. To investigate this, waste hamstring muscle tissue was obtained from eight healthy young men undergoing reconstructive anterior cruciate ligament surgery and primary myoblasts and fibroblasts were isolated. Myoblasts were cultured alone or with fibroblasts, either in direct or indirect contact (separated by an insert with a permeable membrane). The myogenesis parameters proliferation, differentiation, and fusion were determined from immunostained cells, while, in replicate samples, gene expression levels of GAPDH, Ki67, Pax7, MyoD, myogenin, myomaker, MHC-Iβ, TCF7L2, COL1A1, and p16 were determined by RT-PCR. We found only trends for an influence of skeletal muscle fibroblasts on myogenic cell proliferation and differentiation. While greater mRNA levels of GAPDH, Pax7, MyoD, myogenin, and MHC-Iβ were observed in myogenic cells in indirect contact with fibroblasts (insert) when compared with cells cultured alone, a similar effect of an empty insert was also observed. In conclusion we find very little influence of skeletal muscle fibroblasts on myoblasts derived from the same tissue, although it cannot be excluded that a different outcome would be seen under less optimal myogenic growth conditions.NEW & NOTEWORTHY Using passage one primary myoblasts and fibroblasts isolated from human skeletal muscle, we found only a trend for an effect of skeletal muscle fibroblasts on myogenic cell proliferation and differentiation. This is contrary to previous reports and raises the possibility that fibroblasts of different tissue origins exert distinct roles.

Changes in expression levels of brown adipocyte differentiation associated with key genes and reference controls during adipogenesis

Objective To investigate the expression changes in the key differentiation-associated genes and reference genes during the progress of primary brown phagocyte adipocytes. Methods Twenty 4-week-old male C57BL/6J mice were selected randomly and brown adipose tissues were extracted from interscapular area.These brown preadipocytes were cultured in high glucose dulbecco′s modified eagle media, and induced in cocktail culture media (containing 0.5 mmol/L isobutylmethylxanthine, 5 mmol/L Dexamethasone, insulin 320 nmol/L, 1 nmol/L three iodine thyroid original amino acid, and 0.125 mmol/L Indomethacin). The total RNA of brown fat cells in the differentiation process(0, 2, 4, 6 day) were extracted by Trizol RNA isolation assay respectively.And then the RNA quality was verified by agarose gel electrophoresis.Oil red O staining was conducted to detect the maturation of brown fat cells.UCP1, the maker of mature brown fat cells, was detected by immunofluorescence assay.The expression of reference (GAPDH, β-actin, 18S and PPIA) and brown adipocyte differentiation associated genes(UCP1, PRDM16, PGC-1α, EBF2, PPARγ and Cidea) were detected by real-time quantitative PCR(RT-qPCR) method. Results (1)On day 6 of introduction, brown adipocytes were filled with small lipid droplets, and the protein expression of UCP1 increased significantly detected by immunofluorescence.(2)Agarose gel electrophoresis showed 3 bright bands, suggesting a fine RNA quality.(3)The relative gene expression levels of GAPDH, 18S and β-actin existed variations, wheras the expression level of PPIA maintained stable, indicating that PPIA could be used as a reference for differentiation of brown adipose tissues in mouse models during adipogenesis.(4)The expression of brown adipocyte differentiation-associated genes (UCP1, PRDM16, PGC-1α, EBF2, PPARγ and Cidea) increased gradually as time passed(0, 2, 4, 6 day) significantly(all P<0.05). Conclusions PPIA is a suitable reference gene for brown adipocyte differentiation.Brown differen-tiation key genes, such as UCP1, PRDM16, PGC-1α, EBF2, PPARγ and cidea, Could be used as suitable mature marker genes during adipogenesis. Key words: Brown adipocyte; Adipogenesis; Real-time quantitative PCR; Marker gene of brown adipocyte

Abstract 2263: Prognostic significance of REV3like and TYMS gene expression in blood samples from non-small cell lung patients treated with platinum-based chemotherapy plus pemetrexed

Abstract BACKGROUND: Pemetrexed is an effective antineoplastic agent as monotherapy (second line and maintenance setting) or in platinum-based combination regimes (first-line). Pemetrexed inhibits three key enzymes in the folate metabolic pathway: thymidylate synthase (TS), dihydrofolate reductase (DHFR) and glycinamide ribonucleotide formyl transferase (GARFT). As a consequence, pemetrexed interferes with the synthesis of both pyrimidine and purine, thereby effectively inhibiting both DNA and RNA synthesis. The aim of this study was to investigate the impact of the PBMC (peripheral blood mononuclear cells) expression levels of AEG1, BRCA1, REV3like, ant TYMS mRNA in the clinical outcome in NSCLC patients treated with Pemetrexed-based therapy. MATERIAL AND METHODS: This is a prospective, observational cohort study, of consecutively selected patients. We included patients with non-squamous NSCLC, stage IV, treated with platinum-based chemotherapy plus Pemetrexed. Blood samples from each patient were collected at the beginning of treatment. Quantitative reverse transcription (qRT)-PCR was performed with the use of the TaqMan gene expression assay (Applied Biosystems) according to the manufacturer's instructions. Amplifications were carried out on the Applied Biosystem 7500 RT-PCR system, and relative gene expression values were calculated by the ΔΔCt method (Sequence Detection System 2.0.5). Results from analysis, done in triplicate, are expressed relative to expression levels of GAPDH. RESULTS: We here present preliminary results of 16 patients included in the study: median age was 63.4 (range 52-82); 12 were males. Histological subtypes were 13 adenocarcinomas, and 3 large cell carcinomas. Pemetrexed was combined with Carboplatin in 9 patients and Cisplatin in 7 patients. Best response obtained was partial response in 7 patients, stable disease in 3 patients, and progression in 5 patients. We found significant differences in the REV3like expression levels between patients with PR&amp;SD and patients with PD (0.69 ± 0.14 vs 0.44 ± 0.07; P = 0.003). In addition there were statistically significant differences in disease free survival (3 ± 0.74 vs 13 ± 1.89, P = 0.035; 12 ± 2.32 vs 3 ± 2.19, P = 0.003, months), and overall survival (10 ± 5.21 vs not reached, P = 0.026; not reached vs 12 ± 2.38, P = 0.007, months) between patients with mRNA levels of REV3like and TYMS under mean value of the cohort and patients with levels over mean value of the our cohort. CONCLUSIONS: This study supports the value of the PBMC expression profiling of the REV3like and TYMS genes in the prognosis of NSCLC treated with platinum-based chemotherapy plus Pemetrexed. Citation Format: Maria Teresa Agullo-Ortuño, C.Vanessa Díaz-García, José A. López-Martín, Elena Prieto-García, Santiago Ponce, Jon Zugazagoitia, Lara Iglesias-Docampo, Ana B. Enguita, Luis Paz-Ares, Juan A. Nuñez-Sobrino. Prognostic significance of REV3like and TYMS gene expression in blood samples from non-small cell lung patients treated with platinum-based chemotherapy plus pemetrexed. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2263.

Abstract A46: Exposure of quercetin, kaempferol and exogenous glutathione on the expression levels of phospho- and total-Akt in 3T3-L1 preadipocytes

Abstract Obesity has been reported to be a risk factor for several types of cancer. The Akt pathway or PI3K-Akt pathway is a signal transduction pathway that promotes survival and growth in response to extracellular signals. Key proteins involved are phosphatidylinositol 3-kinase (PI3K) and Akt, or Protein Kinase B. Activated Akt mediates downstream responses, including cell survival, growth, proliferation, cell migration and angiogenesis, by phosphorylating a range of intracellular proteins. The effects of the exposure of several doses each of the flavonoids quercetin and kaempferol and that of exogenous glutathione (GSH) (at 0, 5 10, 15, 20 and 25 μM doses) for 24 hr on the expression levels of phospho- and total-Akt levels in 3T3-L1 preadipocytes were investigated. Phospho-, total-Akt and the expression levels of glyceraldehyde 3-phosphate dehydrogenase (GAPDH, which was used as an internal standard) were assayed by the MILLIPLEX® MAP mates protocol, based on the Luminex® xMAP® technology (Millipore Corp. St. Charles, MI). There were no significant differences in the expression levels of GAPDH for the tested compounds and at the different concentrations. Significant (p&amp;lt;0.05) decreases however, in the espression levels of phospho-Akt in cells for the quercetin, kaempferol and GSH treated samples were observed. Total-Akt levels remained the same and, were not significantly different from each other for the tested compounds and at the various concentrations. The results may indicate that exposure of 3T3-L1 preadipocytes to quercetin, kaempferol and GSH did not result in the activation of Akt suggesting the role of such compounds in blocking cell differentiation in 3T3-L1 cells. Thus, quercetin, kaempferol and GSH may significantly cause a decrease in the proliferation of 3T3-L1 preadipocytes, suggesting an association with the low phosphorylation of the Akt protein. Citation Format: William Y. Boadi. Exposure of quercetin, kaempferol and exogenous glutathione on the expression levels of phospho- and total-Akt in 3T3-L1 preadipocytes. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A46.

GAPDH, β-actin and β2-microglobulin, as three common reference genes, are not reliable for gene expression studies in equine adipose- and marrow-derived mesenchymal stem cells.

BackgroundQuantitative real time reverse transcription PCR (qRT-PCR) is one of the most important techniques for gene-expression analysis in molecular based studies. Selecting a proper internal control gene for normalizing data is a crucial step in gene expression analysis via this method. The expression levels of reference genes should be remained constant among cells in different tissues. However, it seems that the location of cells in different tissues might influence their expression. The purpose of this study was to determine whether the source of mesenchymal stem cells (MSCs) has any effect on expression level of three common reference genes (GAPDH, β-actin and β2-microglobulin) in equine marrow- and adipose- derived undifferentiated MSCs and consequently their reliability for comparative qRT-PCR.Materials and methodsAdipose tissue (AT) and bone marrow (BM) samples were harvested from 3 mares. MSCs were isolated and cultured until passage 3 (P3). Total RNA of P3 cells was extracted for cDNA synthesis. The generated cDNAs were analyzed by quantitative real-time PCR. The PCR reactions were ended with a melting curve analysis to verify the specificity of amplicon.ResultsThe expression levels of GAPDH were significantly different between AT- and BM- derived MSCs (p < 0.05). Differences in expression level of β-actin (P < 0.001) and B2M (P < 0.006.) between MSCs derived from AT and BM were substantially higher than GAPDH. In addition, the fold change in expression levels of GAPDH, β-actin and B2M in AT-derived MSCs compared to BM-derived MSCs were 2.38, 6.76 and 7.76, respectively.ConclusionThis study demonstrated that GAPDH and especially β-actin and B2M express in different levels in equine AT- and BM- derived MSCs. Thus they cannot be considered as reliable reference genes for comparative quantitative gene expression analysis in MSCs derived from equine bone marrow and adipose tissue.

Poly r(C) Binding Protein-1 is Central to Maintenance of Cancer Stem Cells in Prostate Cancer Cells

Aims: To investigate global proteomic changes induced in CD44+CD24- stem cells isolated from the prostate cancer cell lines, LNCaP and DU145, post prolonged TGF-β treatment in order to understand underlying mechanisms that promote stemness in prostate cancer cells. Methods: CD44+CD133+α2β1Integrin+CD24- population was isolated from mock or TGF-β treated (7 days) prostate cancer cell line, LNCaP, through fluorescent activated cell sorting. Cell lysates were obtained from the ±TGF-β cell population and proteomics profiling (MS/MS) was performed by mass spectrometry. Relative enrichment or depletion in the CD44+CD24-population post-TGF-β treatment was determined relative to mock-treated CD44+CD24- cells post normalization to GAPDH expression levels. Results obtained from MS/MS were validated using immunoblotting. Functional validation of one putative regulator was performed using gain-of-function strategy to investigate its role in rendering stemness in LNCaP and DU145 cells in vitro and in promoting tumorigenicity in vivo. Results: TGF-β treatment caused significant enrichment of CD44+CD24- population in LNCaP cells (22.35 ± 0.94% in mock treated vs 95.23 ± 2.34% in TGF-β treated cells; P < 0.01), which were also positive for CD133 and α2β1Integrin. Mass spectrometry analysis of the enriched cell population revealed that sixty-three proteins were either up- or down-regulated greater than five folds, out of which the poly r(C) binding protein (PCBP)-1 was the most down-regulated (9.31 ± 0.05 folds). Ectopic overexpression of PCBP1 in LNCaP and DU145 cells not only attenuated enrichment of CD44+CD133+CD24- population in these cells following TGF-β treatment, but also significantly decreased tumorigenicity of the stem cell subset, as assessed by in vitro soft agar colony formation and in vivo xenograft assays. Conclusion: Our proteomic profiling and subsequent validation indicate that PCBP1 is central to CSCs enrichment and functionality in prostate cancer.

A multimarker panel for circulating tumor cells detection predicts patient outcome and therapy response in metastatic colorectal cancer.

Circulating tumor cells (CTCs), proposed as major players in cancer dissemination, have demonstrated clinical prognostic significance in several cancer types. However, their predictive value remains unclear. Here we evaluated the clinical utility of six CTC markers (tissue specific and epithelial to mesenchymal transition transcripts) both as prognostic and predictive tools in metastatic colorectal cancer (mCRC) patients. CTCs were immunoisolated from blood in 50 mCRC patients at baseline and at 4 and 16 weeks after treatment onset. Expression levels of GAPDH, VIL1, CLU, TIMP1, LOXL3 and ZEB2 were determined by qualitative polymerase chain reaction and normalized to the unspecific cell isolation marker CD45. At baseline, median progression-free survival (PFS) and overall survival (OS) for patients with high CTC markers were 6.3 and 12.7 months, respectively, versus 12.7 and 24.2 for patients with low CTC markers (PFS; p = 0.0003; OS; p = 0.044). Concerning response to therapy, PFS and OS for patients with increased CTC markers along treatment were, respectively, 6.6 and 13.1 months, compared with 12.7 and 24.3 for patients presenting CTC markers reduction (PFS; p = 0.004; OS; p = 0.007). Of note, CTC markers identified therapy-refractory patients not detected by standard image techniques. Patients with increased CTC markers along treatment, but classified as responders by computed tomography, showed significantly shorter survival times (PFS: 7.8 vs. 13.2; OS: 14.4 vs. 24.4; months). In conclusion, we have generated a CTC marker panel for prognosis evaluation and the identification of patients benefiting or not from therapy in mCRC. Our methodology efficiently classified patients earlier than routine computed tomography and from a minimally invasive liquid biopsy.

SAT0064 The expression of HDAC6 is reduced in rheumatoid arthritis synovial fibroblasts

BackgroundSince rheumatoid synovial cells produce large amounts of various cytokines and proteases, up to 30% of all newly synthesized proteins are unfolded, leading to a cellular stress condition. Histone-deacetylase (HDAC)...

SPIDIA-RNA: First external quality assessment for the pre-analytical phase of blood samples used for RNA based analyses

The diagnostic use of in vitro molecular assays can be limited by the lack of guidelines for collection, handling, stabilization and storage of patient specimens. One of the major goals of the EC funded project SPIDIA (www.spidia.eu) is to develop evidence-based quality guidelines for the pre-analytical phase of blood samples used for molecular testing which requires intracellular RNA analytes. To this end, a survey and a pan-European external quality assessment (EQA) were implemented. This report is the summary of the results of that trial.With the European Federation of Laboratory Medicine (EFLM) support, 124 applications for participation in the trial were received from 27 different European countries, and 102 laboratories actually participated in the trial. Each participating laboratory described their respective laboratory policies and practices as well as blood collection tubes typically used in performing this type of testing. The participating laboratories received two identical blood specimens: in an EDTA tubes (unstabilized blood; n=67) or in tubes designed specifically for the stabilization of intracellular RNA in blood (PAXgene® Blood RNA tubes; n=35). Laboratories were requested to perform RNA extraction according to the laboratory’s own procedure as soon as possible upon receipt of the tubes for one tube and 24h after the first extraction for the second tube. Participants (n=93) returned the two extracted RNAs to SPIDIA facility for analysis, and provided details about the reagents and protocols they used for the extraction.At the SPIDIA facility responsible for coordinating the study, the survey data were classified, and the extracted RNA samples were evaluated for purity, yield, integrity, stability, and the presence of interfering substances affecting RT-qPCR assays. All participants received a report comparing the performance of the RNA they submitted to that of the other participants. All the results obtained by participants for each RNA quality parameter were classified as “in control”, “warning”, “out of control” and “missing” by consensus mean analysis.From the survey data, the most variable parameters were the volume of blood collected and the time and storage temperature between blood collection and RNA extraction.Analyzing the results of quality testing of submitted RNA samples we observed a data distribution of purity, yield, and presence of assay interference in agreement with expected values. The RNA Integrity Number (RIN) values distribution was, on the other hand, much wider than the optimal expected value, which led to an “in control” classification, even for partly degraded RNA samples. On the other hand, RIN values below 5 significantly correlated with a reduction of GAPDH expression levels. Furthermore, the distribution of the values of the four transcripts investigated (c-fos, IL-1β, IL-8, and GAPDH) was wide and the RNA instability between samples separated by 24h were similar. Assuming the presence of at least two quality parameters “out of control” as an indication of a critical performance of the laboratory, 33% of the laboratories were included in this group.The results of this study will be the basis for implementing a second pan-European EQA and the results of both EQAs will be pooled and will provide the basis for the implementation of evidence-based guidelines for the pre-analytical phase of RNA analysis of blood samples.

Importance of suitable reference gene selection for quantitative real-time PCR: special reference to mouse myocardial infarction studies.

BackgroundQuantitative real-time PCR (qPCR) is a widely used technique for gene expression analysis. Its reliability is highly dependent upon selection of the appropriate reference genes for accurate gene expression normalization. In this study, we investigated the expression stability of 10 commonly used reference genes in a mouse myocardial infarction model.Methods & ResultsThe expression stability of the 10 reference genes (Actb, B2m, Eef1a1, Gapdh, Hprt, Polr2a, Ppia, Rpl13a, Tbp, Tpt1) was analyzed using the geNorm software. Overall, the combination of Hprt, Rpl13a and Tpt1 was the most stable reference gene set in our experiments. Gapdh, Polr2a and Actb consistently showed the highest gene expression variability and the expression levels of Gapdh, Polr2a, Actb, B2m and Eef1a1 were found to be selectively up- or downregulated after myocardial infarction. We normalized the expression of Nppb and Vcam1, using different reference gene strategies and demonstrated that their induction after myocardial infarction was most clearly revealed with the optimal reference gene combination. However, the use of suboptimal reference gene combinations resulted in detrimental effects on gene expression levels and variability with a gradual loss of the expression differences and a significant reduction in statistical power.ConclusionsHprt, Rpl13a and Tpt1 are a set of stably expressed reference genes for accurate gene expression normalization in myocardial infarction studies in mice. We found that Gapdh, Polr2a and Actb display high expression variability in mouse myocardial infarction tissues and that loss of statistical power and increase in sample size are the evident consequences of choosing suboptimal combinations of reference genes. We furthermore caution against the use of Gapdh, Polr2a, Actb, B2m and Eef1a1 for gene expression normalization in myocardial infarction studies because of selective up- or downregulation after myocardial infarction, which could potentially lead to biased study outcomes.

Mutations in CDON, Encoding a Hedgehog Receptor, Result in Holoprosencephaly and Defective Interactions with Other Hedgehog Receptors

Holoprosencephaly (HPE), a common human congenital anomaly defined by a failure to delineate the midline of the forebrain and/or midface, is associated with diminished Sonic hedgehog (SHH)-pathway activity in development of these structures. SHH signaling is regulated by a network of ligand-binding factors, including the primary receptor PTCH1 and the putative coreceptors, CDON (also called CDO), BOC, and GAS1. Although binding of SHH to these receptors promotes pathway activity, it is not known whether interactions between these receptors are important. We report here identification of missense CDON mutations in human HPE. These mutations diminish CDON's ability to support SHH-dependent gene expression in cell-based signaling assays. The mutations occur outside the SHH-binding domain of CDON, and the encoded variant CDON proteins do not display defects in binding to SHH. In contrast, wild-type CDON associates with PTCH1 and GAS1, but the variants do so inefficiently, in a manner that parallels their activity in cell-based assays. Our findings argue that CDON must associate with both ligand and other hedgehog-receptor components, particularly PTCH1, for signaling to occur and that disruption of the latter interactions is a mechanism of HPE.

β-Galactoside α2,6-Sialyltransferase I Cleavage by BACE1 Enhances the Sialylation of Soluble Glycoproteins

BACE1 (beta-site amyloid precursor protein-cleaving enzyme-1) is a membrane-bound aspartic protease that cleaves amyloid precursor protein to produce a neurotoxic peptide, amyloid beta-peptide, and has been implicated in triggering the pathogenesis of Alzheimer disease. We showed previously that BACE1 cleaves beta-galactoside alpha2,6-sialyltransferase I (ST6Gal I) to initiate its secretion, but it remained unclear how BACE1 affects the cellular level of alpha2,6-sialylation. Here, we found that BACE1 overexpression in Hep3B cells increased the sialylation of soluble secreted glycoproteins, but did not affect cell-surface sialylation. The sialylation of soluble glycoproteins was not increased by ST6Gal I overexpression alone, but was increased by co-overexpression of ST6Gal I and BACE1 or by expression of the soluble form of ST6Gal I, suggesting that soluble ST6Gal I produced by BACE1 plays, at least in part, a role in the sialylation of soluble glycoproteins. We also found that plasma glycoproteins from BACE1-deficient mice exhibited reduced levels of alpha2,6-sialylation compared with those from wild-type mice. We propose a novel regulatory mechanism in which cleavage and secretion of ST6Gal I enhance the sialylation of soluble glycoprotein substrates.

ADAM-15/Metargidin Mediates Homotypic Aggregation of Human T Lymphocytes and Heterotypic Interactions of T Lymphocytes with Intestinal Epithelial Cells

Intestinal epithelial cells (IEC) play an immunoregulatory role in the intestine. This role involves cell-cell interactions with intraepithelial lymphocytes that may also play a role in some enteropathies. The discovery of the RGD motif-containing Protein ADAM-15 (a disintegrin and metalloprotease-15) raises the question of its involvement in these cell-cell interactions. Cell adhesion assays were performed using the Jurkat E6.1 T cell line as a model of T lymphocytes and Caco2-BBE monolayers as a model of intestinal epithelia. Our results show that an anti-ADAM-15 ectodomain antibody inhibited the attachment of Jurkat cells on Caco2-BBE monolayers. Overexpression of ADAM-15 in Caco2-BBE cells enhanced Jurkat cell binding, and overexpression of ADAM-15 in Jurkat cells enhanced their aggregation. Mutagenesis experiments showed that both the mutation of ADAM-15 RGD domain or the deletion of its cytoplasmic tail decreased these cell-cell interactions. Moreover, wound-healing experiments showed that epithelial ADAM-15-mediated Jurkat cell adhesion to Caco2-BBE cells enhances the mechanisms of wound repair. We also found that ADAM-15-mediated aggregation of Jurkat cells increases the expression of tumor necrosis factor-alpha mRNA. These results demonstrate the following: 1) ADAM-15 is involved in heterotypic adhesion of intraepithelial lymphocytes to IEC as well as in homotypic aggregation of T cells; 2) both the RGD motif and the cytoplasmic tail of ADAM-15 are involved for these cell-cell interactions; and 3) ADAM-15-mediated cell-cell interactions are involved in mechanisms of epithelial restitution and production of pro-inflammatory mediators. Altogether these findings point to ADAM-15 as a possible therapeutic target for prevention of inappropriate T cell activation involved in some pathologies.

Cannabinoids Ameliorate Pain and Reduce Disease Pathology in Cerulein-Induced Acute Pancreatitis

The functional involvement of the endocannabinoid system in modulation of pancreatic inflammation, such as acute pancreatitis, has not been studied to date. Moreover, the therapeutic potential of cannabinoids in pancreatitis has not been addressed. We quantified endocannabinoid levels and expression of cannabinoid receptors 1 and 2 (CB1 and CB2) in pancreas biopsies from patients and mice with acute pancreatitis. Functional studies were performed in mice using pharmacological interventions. Histological examination, serological, and molecular analyses (lipase, myeloperoxidase, cytokines, and chemokines) were performed to assess disease pathology and inflammation. Pain resulting from pancreatitis was studied as abdominal hypersensitivity to punctate von Frey stimuli. Behavioral analyses in the open-field, light-dark, and catalepsy tests were performed to judge cannabinoid-induced central side effects. Patients with acute pancreatitis showed an up-regulation of cannabinoid receptors and elevated levels of endocannabinoids in the pancreas. HU210, a synthetic agonist at CB1 and CB2, abolished abdominal pain associated with pancreatitis and also reduced inflammation and decreased tissue pathology in mice without producing central, adverse effects. Antagonists at CB1- and CB2-receptors were effective in reversing HU210-induced antinociception, whereas a combination of CB1- and CB2-antagonists was required to block the anti-inflammatory effects of HU210 in pancreatitis. In humans, acute pancreatitis is associated with up-regulation of ligands as well as receptors of the endocannabinoid system in the pancreas. Furthermore, our results suggest a therapeutic potential for cannabinoids in abolishing pain associated with acute pancreatitis and in partially reducing inflammation and disease pathology in the absence of adverse side effects.