scholarly journals The Critical Role of PTEN Mutation in Cellular Process and Drug Selection of Endometrial Cancer

2020 ◽  
Author(s):  
Ying Liu ◽  
Jintuo Zhou ◽  
Peiguang Niu ◽  
Fanxiang Zeng ◽  
Ruihong Cai ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Cell Lines ◽  
Mrna Levels ◽  
Drug Selection ◽  
Ppi Network ◽  
Kegg Analysis ◽  
Pten Mutation ◽  
Mannose Metabolism ◽  
Selection Of

Abstract Background: Phosphatase and tensin homolog (PTEN) is a frequently mutated genes found in endometrial cancer (EC), making it a potential biomarker for individualized treatment opinions. In this study, a method was designed to evaluate the role of the PTEN mutation in the prognosis and drug selection of EC. We identified the potential alterations in pathways and genes related to the mechanism. Methods: cBioPortal database was used to analyze the PTEN mutation status for EC patients. Kaplan-Meier was used to analyze the prognosis of PTEN mutation in EC patients. GDSC dataset was used to identified the drugs that sensitive to cell lines with PTEN mutation. DEGs between PTEN mutation and wide type group were identified using the edgeR package. GO and KEGG analysis were carried out using the DAVID database. GSEA v3.0 were used to dig out the differences in gene mRNA levels of biological function annotation and pathways between PTEN mutation and wide type patients. PPI network of DEGs was performed using STRING and then visualized using Cytoscope software (3.7.2).Results: Our results showed that PTEN mutation was carried in 68% of EC patients. The mRNA expression level of PTEN was lower in patients with PTEN mutation than that with wide type. Prognosis analysis showed that there were favorable overall survival and progression free survival in EC patients with PTEN mutation. Moreover, it is more sensitive to AKT inhibitor (Afuresertib and AZD5363), and Mcl-1 inhibitor (MIM1) on EC cell lines with PTEN mutation than that with wide type. A total of 216 genes were identified as DEGs. GO analysis showed that DEGs significantly enriched in chemical synaptic transmission, extracellular region, etc.. KEGG analysis suggested that DEGs significantly enriched in categories associated with metabolic progression. GSEA analysis identified signaling pathways including fatty acid metabolism, fructose and mannose metabolism, etc.. PPI network analysis identified top 10 genes and top three clusters.Conclusions: Multiple genes and pathways may play an important role in EC patients with PTEN mutation. These results provide a potential target and therapeutic strategies for patients with PTEN mutation.

scholarly journals Nuclear upregulation of PI3K p110β correlates with increased rRNA transcription in endometrial cancer cells

2019 ◽  
Author(s):  
Fatemeh Mazloumi Gavgani ◽  
Thomas Karlsson ◽  
Ingvild L Tangen ◽  
Andrea Papdiné Morovicz ◽  
Victoria Smith Arnesen ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Molecular Mechanisms ◽  
Pi3k Pathway ◽  
Clinical Samples ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Cytoplasmic Staining ◽  
Ec Cells

AbstractGenes encoding for components of the phosphoinositide 3-kinase (PI3K) pathway are frequently mutated in cancer, including inactivating mutations of PTEN and activating mutations of PIK3CA, encoding the PI3K catalytic subunit p110α. PIK3CB, encoding p110β, is rarely mutated, but can contribute to tumourigenesis in some PTEN-deficient tumours. The underlying molecular mechanisms are however poorly understood. By analysing cell lines and annotated clinical samples, we have previously found that p110β is highly expressed in endometrial cancer (EC) cell lines and that PIK3CB mRNA levels increase early in primary tumours correlating with lower survival. Selective inhibition of p110α and p110β led to different effects on cell signalling and cell function, p110α activity being correlated to cell survival in PIK3CA mutant cells and p110β with cell proliferation in PTEN-deficient cells. To understand the mechanisms governing the differential roles of these isoforms, we assessed their sub-cellular localisation. p110α was cytoplasmic whereas p110β was both cytoplasmic and nuclear with increased levels in both compartments in cancer cells. Immunohistochemistry of p110β in clinically annotated patient tumour sections revealed high nuclear/cytoplasmic staining ratio, which correlated significantly with higher grades. Consistently, the presence of high levels of p110β in the nuclei of EC cells, correlated with high levels of its product phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3) in the nucleus. Using immunofluorescence labelling, we observed both p110β and PtdIns(3,4,5)P3 in the nucleoli of EC cell lines. The production of nucleolar PtdIns(3,4,5)P3 was dependent upon p110β activity. EC cells with high levels of nuclear PtdIns(3,4,5)P3 and p110β showed elevated nucleolar activity as assessed by the increase in 47S pre-rRNA transcriptional levels in a p110β-dependent manner. Altogether, these results present a nucleolar role for the PI3K pathway that may contribute to tumour progression in endometrial cancer.

Targeting RNF8 Effectively Reverse Cisplatin and Doxorubicin Resistance in Endometrial Cancer

2020 ◽  
Author(s):  
Ben Yang ◽  
Wang Ke ◽  
Yingchun Wan ◽  
Tao Li
Keyword(s):  
Endometrial Cancer ◽  
Cell Lines ◽  
Quantitative Polymerase Chain Reaction ◽  
Mrna Levels ◽  
Mice Model ◽  
Expression Levels ◽  
Gynecological Malignancy ◽  
Ec Cells

Abstract Background Endometrial cancer (EC) is one of the most frequent gynecological malignancy worldwide. However, resistance to chemotherapy remains one of the major difficulties in the treatment of EC. Thus, there is an urgent requirement to understand mechanisms of chemoresistance and identify novel regimens for patients with EC. Methods Cisplatin and doxorubicin resistant cell lines were acquired by continuous exposing parental EC cells to cisplatin or doxorubicin for 3 months. Cell viability was determined by using MTT assay. Protein Expression levels of protein were examined by western blotting assay. mRNA levels were measured by quantitative polymerase chain reaction (qPCR) assay. Ring finger protein 8 (RNF8) knockout cell lines were generated by clustered regularly interspaced short palindromic repeats (CRISPR)–Cas9 gene editing assay. Nonhomologous end joining (NHEJ) efficiency were quantified by plasmid based NHEJ assay. DNA double strand breaks (DSB) were generated using laser micro-irradiation. Protein recruitment to DSB was analyzed by immunofluorescent assay. Tumor growth was examined by AN3CA xenograft mice model. Results We found that protein and mRNA expression levels of RNF8 were significantly increased in both cisplatin and doxorubicin resistant EC cells. Cell survival assay showed that RNF deficiency significantly enhanced the sensitivity of resistant EC cells to cisplatin and doxorubicin (P < 0.01). In addition, chemoresistant EC cells exhibited increased NHEJ efficiency. Knockout of RNF8 in chemoresistant EC cells significantly reduced NHEJ efficiency and prolonged Ku80 retention on DSB. Moreover, cisplatin resistant AN3CA xenograft showed that RNF8 deficiency overcame cisplatin resistance. Conclusions Our in vitro and in vivo assays provide evidence for RNF8, which is a NHEJ factor, serving as a promising, novel target in EC chemotherapy.

Potentiation of bortezomib's Anti-Myeloma Effects in Combination with Anti-DR5 Agonistic Antibody: The Role of ER Stress in DR5 Editing and DR-Mediated Apoptotic Signaling

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5104-5104
Author(s):  
Hirokazu Miki ◽  
Masahiro Abe ◽  
Kumiko Kagawa ◽  
Asuka Oda ◽  
Hiroe Amou ◽  
...  
Keyword(s):  
Er Stress ◽  
Cell Lines ◽  
Critical Role ◽  
Protein Translation ◽  
Chemotherapeutic Agents ◽  
Mrna Levels ◽  
Trail Receptor ◽  
Normal Peripheral Blood ◽  
Agonistic Antibody

Abstract Abstract 5104 Bortezomib (BTZ) is widely used in the treatment of myeloma (MM) with marked response rates in both relapsed/refractory as well as newly diagnosed MM. However, significant numbers of patients still remain outside benefit of the BTZ treatment; and various combinatory treatments with BTZ have been implemented to improve BTZ's anti-MM effects. On the other hand, immunotherapies seem attractive for yet incurable malignancies by chemotherapeutic agents such as MM and their clinical application has been studied. One such approach is a TNF-related apoptosis-inducing ligand (TRAIL)-mediated immunotherapy. In the present study, we therefore explored the role of BTZ on TRAIL receptor editing and its downstream signaling with special reference to endoplasmic reticulum (ER) stress and the cytotoxic effects of BTZ and anti-TRAIL receptor agonistic antibody in combination on MM cells. Most MM cells expressed DR4 but weakly DR5, while normal peripheral blood mononuclear cells expressed neither DR4 nor DR5. BTZ at 10 nM markedly up-regulated the surface levels of DR5 and its mRNA expression but not those of DR4 in MM cell lines and primary MM cells. Furthermore, BTZ decreased the levels of c-FLIP, an inhibitor of DISC, along with activation of caspase-8 and caspase-3, suggesting potentiation of the DR-mediated extrinsic apoptotic pathway. Consistently, BTZ and anti-DR5 agonistic antibody cooperatively enhanced the cytotoxicity against MM cells. BTZ induced phosphorylation of eIF2alpha, ATF4 and CHOP, along with disappearance of anti-apoptotic proteins including Mcl-1 in MM cells, suggesting the enhancement of ER stress and subsequent suppression of protein translation by BTZ. However, such induction of ER stress by BTZ was not observed in BTZ-resistant MM cell lines, KMS-11/BTZ and OPM-2/BTZ, with a point mutation in BTZ-binding proteasome beta5 subunit (Ri et al. Leukemia 2010). In KMS-11/BTZ and OPM-2/BTZ, surface protein as well as mRNA levels of DR5 were not up-regulated by BTZ, suggesting a critical role of ER stress in up-regulation of DR5 expression by BTZ. Because DR5 expression has been shown to be transcriptionally up-regulated by CHOP, the up-regulation of DR5 mRNA and protein in MM cells by BTZ is suggested to be at least in part due to CHOP induced by BTZ-mediated ER stress. Although BTZ exerts its anti-MM effects through induction of ER stress, the present study demonstrates that induction of ER stress by BTZ is also able to sensitize MM cells to TRAIL-mediated immunotherapy. Therefore, the combination of BTZ and TRAIL-mediated immunotherapy is warranted for further study. Disclosures: No relevant conflicts of interest to declare.

The role of ZNF395 in renal cell carcinoma proliferation, migration, and invasion.

2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 592-592 ◽  
Author(s):  
Chen Zhao ◽  
Christopher G. Wood ◽  
Jose A. Karam ◽  
Tapati Maity ◽  
Lei Wang
Keyword(s):  
Renal Cell Carcinoma ◽  
Tumor Growth ◽  
Cell Carcinoma ◽  
Cell Lines ◽  
Renal Cell ◽  
Migration And Invasion ◽  
Mrna Levels

592 Background: Zinc finger protein 395 (ZNF395) is frequently altered in several tumor types. However, the role of ZNF395 remains poorly studied in patients with clear cell renal cell carcinoma (RCC). In this study, we investigated the in vitro and in vivo role of ZNF395 in ccRCC. Methods: cBioPortal For Cancer Genomics was used to correlate the expression of ZNF395 with RCC patient clinical, pathological and molecular profiles. ZNF395 protein and mRNA levels were studied in several RCC cell lines in vitro. Subsequently, ZNF395 knockdown was performed in 786-O and UMRC3 RCC cells and overexpression was done in Caki-1 and 769-P RCC cells. We then evaluated ZNF395 modulation in these cell lines by in vitro MTT, migration and invasion assays. Finally, we studied the effect of ZNF395 knockout and overexpression in vivo using SCID xenograft models. Results: Patients with higher expression of ZNF395 experienced longer disease-free survival and overall survival. Using in vitro models, we confirmed that knockdown of ZNF395 decreased ZNF395 expression, and increased proliferation, migration and invasiveness of 786-O and UMRC3, while overexpression of ZNF395 increased ZNF395 expression, and reduced proliferation, migration and invasiveness of Caki-1 and 769-P. Using in vivo mouse models, knockdown of ZNF395 expression in 786-O promoted tumor growth while its overexpression in Caki-1 resulted in tumor growth inhibition. We are currently performing experiments to understand the process by which ZNF395 regulates ccRCC pathogenesis. Conclusions: Our data support the role of ZNF395 as an important tumor suppressor gene in the pathogenesis of RCC.

Studies on the role of osteopontin-1 in endometrial cancer cell lines

2013 ◽  
Vol 189 (12) ◽  
pp. 1040-1048 ◽  
Author(s):  
J.C. Hahne ◽  
S.R. Meyer ◽  
P. Kranke ◽  
J. Dietl ◽  
M. Guckenberger ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Cell Lines ◽  
Cancer Cell ◽  
Cancer Cell Lines ◽  
Endometrial Cancer Cell

scholarly journals Smoothened Stabilizes and Protects TRAF6 from Proteosomal Degradation: A Novel Non-Canonical Role of Smoothened with Implications in Lymphoma Biology

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 646-646
Author(s):  
Changju QU ◽  
Amineh Vaghefi ◽  
Kranthi Kunkalla ◽  
Jennifer R Chapman ◽  
Yadong Liu ◽  
...  
Keyword(s):  
Cell Survival ◽  
Cell Lines ◽  
E3 Ligase ◽  
B Cell Lymphoma ◽  
Mrna Levels ◽  
Protein Levels ◽  
Multiple Cancers ◽  
Proteosomal Degradation ◽  
Hh Signaling

Abstract Tumor necrosis factor receptor-associated factor 6 (TRAF6), an (K63) E3-ligase, plays a crucial role in many biological processes and its activity is relevant in the biology of multiple cancers including diffuse large B cell lymphoma (DLBCL). Although molecules that trigger TRAF6 activation have been defined, those that stabilize TRAF6 levels and/or enhance TRAF6 function remain largely unclear. Previously, we found that activation of smoothened (SMO) with recombinant Hedgehog (Hh) ligand increased the binding between SMO with TRAF6, as well as TRAF6 protein levels (Blood 2013; 121:4718-28). In addition, transient overexpression of SMO resulted in increased K63-Ub of both TRAF6 and NEMO indicating stabilization of these proteins resulting in NF-kB activation. This is relevant, as more recently we found that TRAF6 amplifies pAKT signaling in DLBCL and that TRAF6 is the dominant E3 ligase for the K63-Ub of AKT in DLBCL. Moreover, TRAF6 recruitment to the cell membrane, and stabilization of its ubiquitination profile are facilitated by SMO. SMO is a member of the Frizzled-class G-protein-coupled receptor (GPCRs) and is traditionally known for its role as signal transducer in canonical Hedgehog (Hh) signaling. These observations prompted us to investigate whether the ability of SMO to increase TRAF6 levels is limited to ligand induced signaling, whether it contributes to chemoresistance in DLBCL cells, and whether SMO directly participates in controlling TRAF6 levels. To confirm the regulatory role of SMO in the TRAF6/AKT axis in DLBCL cells (HBL1 and HT) and further outline the nature of the underlying regulation, we measured the impact of activation of the Hh pathway with recombinant Shh ligand on TRAF6 levels, with and without SMO knockdown or recombinant SMO overexpression. Canonical Hh signaling results in the activation of the GLI1 transcription factor and the subsequent elevation of GLI1 mRNA levels is an established indicator of activation of the Hh pathway. However, neither SMO activation nor the knockdown of GLI1 had a significant impact on TRAF6 mRNA levels. These findings indicate that TRAF6 is not transcriptionally regulated by SMO signaling through GLI1 (canonical Hh signaling). In contrast, overexpression of SMO or siRNA knockdown of SMO resulted in an increase or decrease of TRAF6 protein levels, respectively. Consistent with the decrease of AKT activation (pAKT T308 and S473) after TRAF6 knockdown, the increase in TRAF6 levels that follows SMO overexpression resulted in an increase in the levels of AKT phosphorylation. Altogether, these observations suggest a post-translational regulation of TRAF6 by SMO. Indeed, stable knockdown of SMO dramatically reduces the half-life of TRAF6 in both HBL1 and HT cells in the presence of cyclohexamide. Furthermore, overexpression of SMO increases K63-Ub of both TRAF6 and AKT. In contrast, the SMO induced decrease in K48-Ub occurred only for TRAF6 but not for AKT. These data link the SMO-stimulated activation of TRAF6 to the enhancement of AKT signaling and protection of TRAF6 from proteasomal degradation. Mechanistically, we found that SMO, through its C-terminal tail, stabilizes TRAF6 and protects TRAF6 from proteosomal degradation, an effect mediated by ubiquitin-specific protease-8 (USP8). Importantly, this functional link between SMO and TRAF6 is reflected in DLBCL patient samples where high expression of both molecules correlates with poor prognosis. Resistance to DXR is a serious challenge in the treatment of DLBCL, and activated AKT is known to contribute to DXR resistance in multiple cancers including DLBCL. We evaluated whether SMO and TRAF6 support resistance to DXR in DLBCL cell lines. We exposed HT and HBL1 cells as well as their counterparts with stable knockdown of TRAF6 or SMO to DXR for 96hrs. Cell viability after exposure to DXR was determined by an Annexin V and PI staining assay. Silencing SMO or TRAF6 dramatically decreased cell survival after treatment with DXR. In summary, we report that SMO is needed to facilitate and maintain TRAF6-dependent elevated pAKT levels in DLBCL cell lines of germinal (GC) and non-GC subtypes, and that the SMO/TRAF6 axis contributes to DXR resistance in DLBCL. Our study reveals a novel and potential central cell survival signaling mechanism in which SMO stabilizes and protects TRAF6 from proteosomal degradation. Disclosures Lossos: Affimed: Research Funding.

scholarly journals Overexpression of SKA Complex Is Associated With Poor Prognosis in Gliomas

2022 ◽  
Vol 12 ◽  
Author(s):  
Shoukai Yu
Keyword(s):  
Chromosome Segregation ◽  
Poor Prognosis ◽  
Nuclear Division ◽  
Prognostic Significance ◽  
Mrna Levels ◽  
Ppi Network ◽  
Hub Genes ◽  
Protein Protein Interaction ◽  
Spindle Microtubules

The spindle and kinetochore-associated complex is composed of three members: SKA1, SKA2, and SKA3. It is necessary for stabilizing spindle microtubules attaching to kinetochore (KT) in the middle stage of mitosis. The SKA complex is associated with poor prognosis in several human cancers. However, the role of SKA complex in rare malignant diseases, such as gliomas, has not been fully investigated. We investigated several databases, including Oncomine, UALCAN, and cBioPortal to explore the expression profile and prognostic significance of SKA complex in patients with gliomas. Gene ontology and Kyoto Encyclopedia of Genes and Genome pathways were used to analyze the potential enriched pathways. The genes co-expressed with SKA complex were identified and used for developing a protein-protein interaction (PPI) network using the STRING database. We found a significant overexpression of the mRNA levels of SKA1, SKA2, and SKA3 in patients with glioma patients. Higher expression of SKA1 and SKA3, but not SKA2, was significantly correlated with shorter overall survival of patients with glioma. In glioma, SKA complex was found to be involved in nuclear division, chromosome segregation, and DNA replication. The results of PPI network identified 10 hub genes (CCNB2, UBE2C, BUB1B, TPX2, CCNA2, CCNB1, MELK, TOP2A, PBK, and KIF11), all of which were overexpressed and negatively associated with prognosis of patients with glioma. In conclusion, our study sheds new insights into the biological role and prognostic significance of SKA complex in glioma.

scholarly journals Role of epigenetic factors in the selection of the alternative splicing isoforms of human KRAS in colorectal cancer cell lines

Oncotarget ◽  
2018 ◽  
Vol 9 (29) ◽  
pp. 20578-20589 ◽  
Author(s):  
Ángela L. Riffo-Campos ◽  
Francisco Gimeno-Valiente ◽  
Fernanda M. Rodríguez ◽  
Andrés Cervantes ◽  
Gerardo López-Rodas ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Alternative Splicing ◽  
Cell Lines ◽  
Cancer Cell ◽  
Colorectal Cancer Cell ◽  
Epigenetic Factors ◽  
Colorectal Cancer Cell Lines ◽  
Splicing Isoforms ◽  
Selection Of

MiR-134, Mediated by IRF1, Suppresses Tumorigenesis and Progression by Targeting VEGFA and MYCN in Osteosarcoma

2020 ◽  
Vol 20 (10) ◽  
pp. 1197-1208
Author(s):  
Zhuo Ma ◽  
Kai Li ◽  
Peng Chen ◽  
Qizheng Pan ◽  
Xuyang Li ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Lines ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Mrna Levels ◽  
Invasion And Migration ◽  
And Migration

Background: Osteosarcoma (OS) is a prevalent primary bone malignancy and its distal metastasis remains the main cause of mortality in OS patients. MicroRNAs (miRNAs) play critical roles during cancer metastasis. Objective: Thus, elucidating the role of miRNA dysregulation in OS metastasis may provide novel therapeutic targets. Methods: The previous study found a low miR-134 expression level in the OS specimens compared with paracancer tissues. Overexpression of miR-134 stable cell lines was established. Cell viability assay, cell invasion and migration assay and apoptosis assay were performed to evaluate the role of miR-134 in OS in vitro. Results: We found that miR-134 overexpression inhibits cell proliferation, migration and invasion, and induces cell apoptosis in both MG63 and Saos-2 cell lines. Mechanistically, miR-134 targets the 3'-UTR of VEGFA and MYCN mRNA to silence its translation, which was confirmed by luciferase-reporter assay. The real-time PCR analysis illustrated that miR-134 overexpression decreases VEGFA and MYCN mRNA levels. Additionally, the overexpression of VEGFA or MYCN can partly attenuate the effects of miR-134 on OS cell migration and viability. Furthermore, the overexpression of miR-134 dramatically inhibits tumor growth in the human OS cell line xenograft mouse model in vivo. Moreover, bioinformatic and luciferase assays indicate that the expression of miR-134 is regulated by Interferon Regulatory Factor (IRF1), which binds to its promoter and activates miR-134 expression. Conclusion: Our study demonstrates that IRF1 is a key player in the transcriptional control of miR-134, and it inhibits cell proliferation, invasion and migration in vitro and in vivo via targeting VEGFA and MYCN.

Junctional Adhesion Molecule-A/ F11 Receptor (JAM-A/ F11R) Expression in Multiple Myeloma (MM): a Candidate Biomarker of Aggressive Disease.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2830-2830
Author(s):  
Bani M Azari ◽  
Marc J. Braunstein ◽  
H. Uwe Kluppelberg ◽  
Sadeaqua S Scott ◽  
Eric LP Smith ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Multiple Myeloma ◽  
Bone Marrow ◽  
Flow Cytometry ◽  
Tumor Cells ◽  
Cell Lines ◽  
Adhesion Molecule ◽  
Mrna Levels

Abstract Abstract 2830 Poster Board II-806 Background: Multiple myeloma (MM) is an incurable disease of clonal plasma cells that accumulate in the bone marrow (BM), causing monoclonal IG production, bone marrow failure, osteolytic lesions and kidney disease. Although initially treatable, MM ultimately becomes refractory to treatment, and is invariably fatal, when tumor cells that harbor genetic mutations expand without regulation. Therefore novel treatment targets need to be identified. A key mechanism in MM pathogenesis is regulation of tumor growth by the bone marrow (BM) microenvironment, particularly by bone marrow neo-vascularization and adhesion of tumor cells to the marrow stroma. Aberrantly expressed genes that regulate angiogenesis by MM cells enhance MM progression and constitute targets in its treatment. JAM-A/F11R is an endothelial cell (EC) adhesion molecule of the immunoglobulin superfamily which is a multifunctional cell membrane protein that mediates intracellular signaling events that alter EC migration and paracellular permeability. For example, in breast cancer, attenuation of JAM-A increases tumor invasion and metastasis through a decrease in tumor adhesion (Ulas Naik Cell Adh Migr. 2008 Oct;2(4):249-51.). In this study we explored the JAM-A/F11R expression in MM tumor cells and in patients to determine the potential role of this molecule in the pathogenesis and progression of MM. Methods: The MM cell lines examined were RPMI-8266, U266, and NCI-H929. Human umbilical vein endothelial cells (HUVECs) served as controls. Informed consent was obtained from patients and control subjects. Primary BM tumor cells were enriched to > 95% CD138+ cells by positive selection using anti-CD138 MACS MicroBeads. The CD138-negative fraction was used for outgrowth of confluent EPCs (> 98% vWF/CD133/KDR+). JAM-A mRNA expression was assessed using an microarray gene expression profile, JAM-A probe based real-time PCR, and JAM-A levels in each sample were measure using a standard curve and normalized to GADPH. JAM-A protein levels in MM cell lines and primary tumor cells were measured by flow cytometry and immunofluorescence. For serum studies, peripheral blood was obtained from 25 newly diagnosed MM patients and 8 healthy, age- and sex-matched controls, and JAM-A levels were measured using an ELISA. Statistical analysis was performed using Student's t-test, two-tailed, with P ' .05 considered significant. Results: JAM-A mRNA levels were significantly increased in MM cell lines RPMI-8266, U266, and NCI-H929 compared to HUVECs (U266, P = 3×10-5; RPM1-8266, P = 1×10-6; NC1-H929, P= 5×10-4). The JAM-A mRNA levels were significantly greater in RPMI-8226; P < .04 compared to TNFα-activated HUVECs for 24 hours which is a proangiogenic switch for HUVEC gene expression. The elevated mRNA expression of the JAM-A in MM cell lines was confirmed by immunofluorescence and flow cytometry which showed the presence of both membrane and cytoplasmic JAM-A protein. Microarray analysis of gene expression profiles from 20 patients' corresponding tumor cells and microenvironmental EPCs showed that JAM-A had a higher level of expression in tumor cells versus MM EPC by 12.62 fold, (P=.0000642). Furthermore, JAM-A had a higher level of expression in MM EPC versus normal control EPC by 2.41 fold, (P=.00113) reflecting a complex regulatory role of F11 signaling in MM, similar to breast cancer (Naik, U. et al 2008). JAM-A was also found to be 12.6 fold greater in tumor cells compared to EPCS (P=.0000642). In addition, circulating levels of soluble JAM-A were found to be significantly greater in the serum of MM patients compared to controls (P < .005), with an average 2-fold increase. Serum levels of JAM-A in MM patients also decreased 71% with treatment n=5, P<.05. Conclusion: We show for the first time that JAM-A expression is highly elevated in MM tumor cells and its levels respond to treatment. In addition, MM patients have higher circulating JAM-A levels compared to healthy individuals and circulating JAM-A levels were reduced following treatment, suggesting that JAM-A may serve as a novel biomarker in MM. Current studies in the lab are aimed at correlating these levels with clinical parameters to determine whether JAM-A levels reflect disease severity and response to treatment. Results of these analyses, as well as results of ongoing experiments using JAM-A siRNA and antibody-inhibition approaches to target JAM-A in myeloma tumor and ECs will be presented. Disclosures: No relevant conflicts of interest to declare.

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