Gene Summary

Gene:TYRO3; TYRO3 protein tyrosine kinase
Aliases: BYK, Dtk, RSE, Rek, Sky, Tif, Etk-2
Summary:The gene is part of a 3-member transmembrane receptor kinase receptor family with a processed pseudogene distal on chromosome 15. The encoded protein is activated by the products of the growth arrest-specific gene 6 and protein S genes and is involved in controlling cell survival and proliferation, spermatogenesis, immunoregulation and phagocytosis. The encoded protein has also been identified as a cell entry factor for Ebola and Marburg viruses. [provided by RefSeq, May 2010]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:tyrosine-protein kinase receptor TYRO3
Source:NCBIAccessed: 11 March, 2017


What does this gene/protein do?
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Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 11 March 2017 using data from PubMed using criteria.

Literature Analysis

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Tag cloud generated 11 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (8)

Latest Publications: TYRO3 (cancer-related)

Oliveira CC, Maciel-Guerra H, Kucko L, et al.
Double-hit lymphomas: clinical, morphological, immunohistochemical and cytogenetic study in a series of Brazilian patients with high-grade non-Hodgkin lymphoma.
Diagn Pathol. 2017; 12(1):3 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Double-hit lymphomas (DHL) are rare high-grade neoplasms characterized by two translocations: one involving the gene MYC and another involving genes BCL2 or BCL6, whose diagnosis depends on cytogenetic examination. This research studied DHL and morphological and/or immunophenotypic factors associated with the detection of these translocations in a group of high-grade non-Hodgkin lymphoma cases.
METHOD: Clinical and morphological reviews of 120 cases diagnosed with diffuse large B-cell lymphoma and Burkitt lymphoma were conducted. Immunohistochemistry (CD20, CD79a, PAX5, CD10, Bcl6, Bcl2, MUM1, TDT and Myc) and fluorescence in situ hybridization for detection of MYC, BCL2 and BCL6 gene translocations were performed in a tissue microarray platform.
RESULTS: Three cases of DHL were detected: two with translocations of MYC and BCL2 and one with translocations of MYC and BCL6, all leading to death in less than six months. Among 90 cytogenetically evaluable biopsies, associations were determined between immunohistochemistry and fluorescence in situ hybridization for MYC (p = 0.036) and BCL2 (p = 0.001). However, these showed only regular agreement, indicated by Kappa values of 0.23 [0.0;0.49] and 0.35 [0.13;0.56], respectively. "Starry sky" morphology was strongly associated with MYC positivity (p = 0.01). The detection of three cases of DHL, all resulting in death, confirms the rarity and aggressiveness of this neoplasm.
CONCLUSIONS: The "starry sky" morphological pattern and immunohistochemical expression of Myc and Bcl2 represent possible selection factors for additional cytogenetic diagnostic testing.

Kimani SG, Kumar S, Davra V, et al.
Normalization of TAM post-receptor signaling reveals a cell invasive signature for Axl tyrosine kinase.
Cell Commun Signal. 2016; 14(1):19 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Tyro3, Axl, and Mertk (TAMs) are a family of three conserved receptor tyrosine kinases that have pleiotropic roles in innate immunity and homeostasis and when overexpressed in cancer cells can drive tumorigenesis.
METHODS: In the present study, we engineered EGFR/TAM chimeric receptors (EGFR/Tyro3, EGFR/Axl, and EGF/Mertk) with the goals to interrogate post-receptor functions of TAMs, and query whether TAMs have unique or overlapping post-receptor activation profiles. Stable expression of EGFR/TAMs in EGFR-deficient CHO cells afforded robust EGF inducible TAM receptor phosphorylation and activation of downstream signaling.
RESULTS: Using a series of unbiased screening approaches, that include kinome-view analysis, phosphor-arrays, RNAseq/GSEA analysis, as well as cell biological and in vivo readouts, we provide evidence that each TAM has unique post-receptor signaling platforms and identify an intrinsic role for Axl that impinges on cell motility and invasion compared to Tyro3 and Mertk.
CONCLUSION: These studies demonstrate that TAM show unique post-receptor signatures that impinge on distinct gene expression profiles and tumorigenic outcomes.

Michna A, Schötz U, Selmansberger M, et al.
Transcriptomic analyses of the radiation response in head and neck squamous cell carcinoma subclones with different radiation sensitivity: time-course gene expression profiles and gene association networks.
Radiat Oncol. 2016; 11:94 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Acquired and inherent radioresistance of tumor cells is related to tumor relapse and poor prognosis - not only in head and neck squamous cell carcinoma (HNSCC). The underlying molecular mechanisms are largely unknown. Therefore, systemic in-depth analyses are needed to identify key regulators of radioresistance. In the present study, subclones of the CAL-33 HNSCC cell line with different radiosensitivity were analyzed to identify signaling pathways related to the different phenotypes.
METHODS: Subclones with altered radiosensitivity were generated by fractionated irradiation of the parental CAL-33 cells. Differences in radiosensitivity were confirmed in colony formation assays. Selected subclones were characterized at the genomic and transcriptomic level by SKY, array CGH, and mRNA-microarray analyses. Time-course gene expression analyses upon irradiation using a natural cubic spline regression model identified temporally differentially expressed genes. Moreover, early and late responding genes were identified. Gene association networks were reconstructed using partial correlation. The Reactome pathway database was employed to conduct pathway enrichment analyses.
RESULTS: The characterization of two subclones with enhanced radiation resistance (RP) and enhanced radiosensitivity (SP) revealed distinct genomic and transcriptomic changes compared to the parental cells. Differentially expressed genes after irradiation shared by both subclones pointed to important pathways of the early and late radiation response, including senescence, apoptosis, DNA repair, Wnt, PI3K/AKT, and Rho GTPase signaling. The analysis of the most important nodes of the gene association networks revealed pathways specific to the radiation response in different phenotypes of radiosensitivity. Exemplarily, for the RP subclone the senescence-associated secretory phenotype (SASP) together with GPCR ligand binding were considered as crucial. Also, the expression of endogenous retrovirus ERV3-1in response to irradiation has been observed, and the related gene association networks have been identified.
CONCLUSIONS: Our study presents comprehensive gene expression data of CAL-33 subclones with different radiation sensitivity. The resulting networks and pathways associated with the resistant phenotype are of special interest and include the SASP. The radiation-associated expression of ERV3-1 also appears highly attractive for further studies of the molecular mechanisms underlying acquired radioresistance. The identified pathways may represent key players of radioresistance, which could serve as potential targets for molecularly designed, therapeutical intervention.

Pharoah PD, Song H, Dicks E, et al.
PPM1D Mosaic Truncating Variants in Ovarian Cancer Cases May Be Treatment-Related Somatic Mutations.
J Natl Cancer Inst. 2016; 108(3) [PubMed] Free Access to Full Article Related Publications
Mosaic truncating mutations in the protein phosphatase, Mg(2+)/Mn(2+)-dependent, 1D (PPM1D) gene have recently been reported with a statistically significantly greater frequency in lymphocyte DNA from ovarian cancer case patients compared with unaffected control patients. Using massively parallel sequencing (MPS) we identified truncating PPM1D mutations in 12 of 3236 epithelial ovarian cancer (EOC) case patients (0.37%) but in only one of 3431 unaffected control patients (0.03%) (P = .001). All statistical tests were two-sided. A combination of Sanger sequencing, pyrosequencing, and MPS data suggested that 12 of the 13 mutations were mosaic. All mutations were identified in post-chemotherapy treatment blood samples from case patients (n = 1827) (average 1234 days post-treatment in carriers) rather than from cases collected pretreatment (less than 14 days after diagnosis, n = 1384) (P = .002). These data suggest that PPM1D variants in EOC cases are primarily somatic mosaic mutations caused by treatment and are not associated with germline predisposition to EOC.

Brisam M, Rauthe S, Hartmann S, et al.
Expression of MAGE-A1-A12 subgroups in the invasive tumor front and tumor center in oral squamous cell carcinoma.
Oncol Rep. 2016; 35(4):1979-86 [PubMed] Related Publications
MAGE-A proteins are highly expressed in oral squamous cell carcinoma (OSCC) and are promising targets for cancer immunotherapy. This study examined the presence of MAGE-A expression within the tumor center (TC) and tumor invasive front (TIF) and evaluated its relationship to poor prognosis. The expression rate of each MAGE-A subtype, A1-A12, was examined in 68 OSCCs at the TIF and TC. Slides (1-µm) of tissue microarrays (diameter =0.6 mm) were immunohistochemically stained, and the findings were correlated to clinical data. Approximately 95% of the tumors had MAGE-A expression. Higher expression in the TC was shown significantly for MAGE-A1, -A5, -A6, -A9 and -A12 (P<0.05). MAGE-A2 and -A3 exhibited the opposite behavior (not significant, P>0.05). Age, tumor size, grade and survival time were not associated with the expression of certain MAGE-A subgroups. When expression in the whole tumor tissue was considered, only MAGE-A1 was expressed at a significantly higher rate in male patients (P=0.034). At the TIF, MAGE-A9 and the UICC disease stage were significantly correlated (P=0.0263), and MAGE-A6 and the UICC disease stage exhibited a strong trend (P=0.0596). The expression of MAGE-A3, -A4, -A5, -A9 and -A11 was significantly associated with lymph node metastasis, while MAGE-A4 was expressed in all regions of the tumors (TIF and TC). This study showed that higher expression of most MAGE-A antigens occurred at the TC rather than at the TIF. MAGE‑A1, -A3, -A4, -A5, -A9 and -A11 were significantly associated with clinically advanced stages of disease and seem to be of particular interest.

Wang Y, Shan Q, Hou G, et al.
Discovery of potential colorectal cancer serum biomarkers through quantitative proteomics on the colonic tissue interstitial fluids from the AOM-DSS mouse model.
J Proteomics. 2016; 132:31-40 [PubMed] Related Publications
UNLABELLED: Quantitative proteomic analysis was performed using iTRAQ to discover colorectal cancer (CRC)-related proteins in tissue interstitial fluids (TIFs). A typical inflammation-related CRC mouse model was generated using azoxymethane-dextran sodium sulfate (AOM-DSS), and TIFs were collected from these mice in four stages during CRC development. Using stringent criteria, a total of 144 proteins displayed changes in their abundances during tumor growth, including 45 that consecutively increased, 17 that consecutively decreased and 82 that changed irregularly. Of these 144 proteins, 24 of the consecutively changed proteins were measured using MRM in individual TIF samples, and 18 were verified. Twelve proteins verified to be consecutively increased in TIFs were examined using MRM to evaluate changes in their abundance in individual mouse serum samples. The abundances of leucine-rich alpha-2-glycoprotein 1 (LRG1), tubulin beta-5 chain (TUBB5) and immunoglobulin J chain (IGJ) were significantly higher in CRC mice than in control mice. Using clinical samples and MRM, we further verified that LRG1 and TUBB5 are potential CRC serum biomarkers. These data demonstrate that coupling dynamic TIF proteomics with targeted serum proteomics in an animal model is a promising avenue for pursuing the discovery of tumor serum biomarkers.
BIOLOGICAL SIGNIFICANCE: Colorectal cancer (CRC) is one of the most dangerous diseases worldwide. However, few of CRC biomarkers possess satisfied specificity and sensitivity in clinical practices. Exploration of more CRC biomarkers, especially in serum, is an urgent and also a time-consuming campaign in the CRC study. Our study demonstrates that quantitatively evaluating the phase-dependent proteins in colonic tissue interstitial fluids from AOM-DSS mice is a feasible and effective way for exploration of the CRC-related proteins and the potential serum biomarkers. We identified two proteins, LRG1 and TUBB5, which may be practicable in human clinical samples as CRC serum biomarkers. To sum up, this study provides a novel angle to explore the critical factors in tumorigenesis and a new pipeline for potential serum biomarker discovery and verification.

Duan Y, Wong W, Chua SC, et al.
Overexpression of Tyro3 and its implications on hepatocellular carcinoma progression.
Int J Oncol. 2016; 48(1):358-66 [PubMed] Related Publications
While various tyrosine kinases have been associated with the pathogenesis of hepatocellular carcinoma (HCC), the identification of a dominant therapeutic target among them remains a challenge. Here, we investigated the role of Tyro3, a relatively uncharacterized member of the TAM (Tyro3, Axl and Mer) receptor family. The present study aimed to profile and identify potential association between Tyro3 expression in HCC and cancer phenotypes. RNAs obtained from 55 HCC patients were quantified for Tyro3 expression in both cancerous tissue and the adjacent normal tissue. Expression profile was correlated with clinical data. These observations were further substantiated with in vitro HCC cell culture investigations.Tyro3 was strongly upregulated (>2-fold elevation) in the tumor tissue of ~42% of the patients. It was shown that higher expression level of Tyro3 was associated with the key tumor marker AFP, and the tumor diameter and liver injury marker ALT. Subsequent cell culture models indicated high expression in various HCC cell lines, in particular Hep3B. Gene silencing of Tyro3 in Hep3B effectively reduced cell proliferation, ERK phosphorylation and cyclin D1 expression, indicating a key in maintaining the proliferative state of these cells. Notably, silencing also suppressed the transcriptional and translational expression of HCC tumor marker AFP. Overall, these data suggest that Tyro3 contributes significantly to tumor growth, aggressiveness and liver dysfunction. Inhibition of Tyro3 and its aberrant signaling in tumors with high expression could present new opportunities for HCC treatment.

Chang QA, Qasem A, Madhusudhana S, Glazyrin A
The t(14;18)(q32;q21) with extra MYC signal - is it a gray zone lymphoma?
Int J Clin Exp Pathol. 2015; 8(8):9602-8 [PubMed] Free Access to Full Article Related Publications
Double-hit lymphomas (DHL) are defined as B-cell lymphoma with a chromosomal breakpoint affecting the MYC/8q24 locus in combination with rearrangement at (14;18)(q32;q21). We recently observed three cases of B-cell lymphoma with an extra intact MYC signal in association with the t(14;18)(q32;q21) translocation. The impact of an extra copy of MYC to the clinical course and prognosis of one patient with Diffuse Large B Cell Lymphoma (DLBCL) and two patients with Follicular Lymphoma (FL) was evaluated. Flow cytometry in all cases demonstrated lambda- or kappa-light chain restricted CD20 and CD10 positive neoplastic B cells. FISH analysis was negative for MYC gene rearrangement but demonstrated an extra copy of intact MYC. Tissue sections displayed typical starry sky "gray zone" lymphoma morphology in case of DLBCL and FL morphology in cases 2 and 3, with high Ki67 labeling in all three cases. All patients responded well to initial chemotherapy although displayed variant outcome after initial remission. The patient with DLBCL deceased within a year of diagnosis while the other two patients with FL showed much better overall survival. Our limited experience showed that additional copy of intact MYC may be equivalent to "classic" DHL on the background of DLBCL with additional cytogenetic abnormalities, however isolated t(14;18)(q32;q21) translocation in combination with additional copy of intact MYC may demonstrate histology and clinical outcome more comparable with "classic" low grade follicular lymphoma, albeit with more aggressive morphology.

Tanaka Y, Yano H, Ogasawara S, et al.
Mild Glucose Starvation Induces KDM2A-Mediated H3K36me2 Demethylation through AMPK To Reduce rRNA Transcription and Cell Proliferation.
Mol Cell Biol. 2015; 35(24):4170-84 [PubMed] Free Access to Full Article Related Publications
Environmental conditions control rRNA transcription. Previously, we found that serum and glucose deprivation induces KDM2A-mediated H3K36me2 demethylation in the rRNA gene (rDNA) promoter and reduces rRNA transcription in the human breast cancer cell line MCF-7. However, the molecular mechanism and biological significance are still unclear. In the present study, we found that glucose starvation alone induced the KDM2A-dependent reduction of rRNA transcription. The treatment of cells with 2-deoxy-d-glucose, an inhibitor of glycolysis, reduced rRNA transcription and H3K36me2 in the rDNA promoter, both of which were completely dependent on KDM2A in low concentrations of 2-deoxy-d-glucose, that is, mild starvation conditions. The mild starvation induced these KDM2A activities through AMP-activated kinase (AMPK) but did not affect another AMPK effector of rRNA transcription, TIF-IA. In the triple-negative breast cancer cell line MDA-MB-231, the mild starvation also reduced rRNA transcription in a KDM2A-dependent manner. We detected KDM2A in breast cancer tissues irrespective of their estrogen receptor, progesterone receptor, and HER2 status, including triple-negative cancer tissues. In both MCF-7 and MDA-MB-231 cells, mild starvation reduced cell proliferation, and KDM2A knockdown suppressed the reduction of cell proliferation. These results suggest that under mild glucose starvation AMPK induces KDM2A-dependent reduction of rRNA transcription to control cell proliferation.

Ramus SJ, Song H, Dicks E, et al.
Germline Mutations in the BRIP1, BARD1, PALB2, and NBN Genes in Women With Ovarian Cancer.
J Natl Cancer Inst. 2015; 107(11) [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy, responsible for 13 000 deaths per year in the United States. Risk prediction based on identifying germline mutations in ovarian cancer susceptibility genes could have a clinically significant impact on reducing disease mortality.
METHODS: Next generation sequencing was used to identify germline mutations in the coding regions of four candidate susceptibility genes-BRIP1, BARD1, PALB2 and NBN-in 3236 invasive EOC case patients and 3431 control patients of European origin, and in 2000 unaffected high-risk women from a clinical screening trial of ovarian cancer (UKFOCSS). For each gene, we estimated the prevalence and EOC risks and evaluated associations between germline variant status and clinical and epidemiological risk factor information. All statistical tests were two-sided.
RESULTS: We found an increased frequency of deleterious mutations in BRIP1 in case patients (0.9%) and in the UKFOCSS participants (0.6%) compared with control patients (0.09%) (P = 1 x 10(-4) and 8 x 10(-4), respectively), but no differences for BARD1 (P = .39), NBN1 ( P = .61), or PALB2 (P = .08). There was also a difference in the frequency of rare missense variants in BRIP1 between case patients and control patients (P = 5.5 x 10(-4)). The relative risks associated with BRIP1 mutations were 11.22 for invasive EOC (95% confidence interval [CI] = 3.22 to 34.10, P = 1 x 10(-4)) and 14.09 for high-grade serous disease (95% CI = 4.04 to 45.02, P = 2 x 10(-5)). Segregation analysis in families estimated the average relative risks in BRIP1 mutation carriers compared with the general population to be 3.41 (95% CI = 2.12 to 5.54, P = 7×10(-7)).
CONCLUSIONS: Deleterious germline mutations in BRIP1 are associated with a moderate increase in EOC risk. These data have clinical implications for risk prediction and prevention approaches for ovarian cancer and emphasize the critical need for risk estimates based on very large sample sizes before genes of moderate penetrance have clinical utility in cancer prevention.

Ray DB, Merrill GA, Brenner FJ, et al.
T24 HRAS transformed NIH/3T3 mouse cells (GhrasT-NIH/3T3) in serial tumorigenic in vitro/in vivo passages give rise to increasingly aggressive tumorigenic cell lines T1-A and T2-A and metastatic cell lines T3-HA and T4-PA.
Exp Cell Res. 2016; 340(1):1-11 [PubMed] Related Publications
Cancer cells often arise progressively from "normal" to "pre-cancer" to "transformed" to "local metastasis" to "metastatic disease" to "aggressive metastatic disease". Recent whole genome sequencing (WGS) and spectral karyotyping (SKY) of cancer cells and tumorigenic models have shown this progression involves three major types of genome rearrangements: ordered small step-wise changes, more dramatic "punctuated evolution" (chromoplexy), and large catastrophic steps (chromothripsis) which all occur in random combinations to generate near infinite numbers of stochastically rearranged metastatic cancer cell genomes. This paper describes a series of mouse cell lines developed sequentially to mimic this type of progression. This starts with the new GhrasT-NIH/Swiss cell line that was produced from the NIH/3T3 cell line that had been transformed by transfection with HRAS oncogene DNA from the T24 human bladder carcinoma. These GhrasT-NIH/Swiss cells were injected s.c. into NIH/Swiss mice to produce primary tumors from which one was used to establish the T1-A cell line. T1-A cells injected i.v. into the tail vein of a NIH/Swiss mouse produced a local metastatic tumor near the base of the tail from which the T2-A cell line was established. T2-A cells injected i.v. into the tail vein of a nude NIH/Swiss mouse produced metastases in the liver and one lung from which the T3-HA (H=hepatic) and T3-PA (P=pulmonary) cell lines were developed, respectively. T3-HA cells injected i.v. into a nude mouse produced a metastasis in the lung from which the T4-PA cell line was established. PCR analysis indicated the human T24 HRAS oncogene was carried along with each in vitro/in vivo transfer step and found in the T2-A and T4-PA cell lines. Light photomicrographs indicate that all transformed cells are morphologically similar. GhrasT-NIH/Swiss cells injected s.c. produced tumors in 4% of NIH/Swiss mice in 6-10 weeks; T1-A cells injected s.c. produced tumors in 100% of NIH/Swiss mice in 7-10 days. T1-A, T-2A, T3-HA and T4-PA cells when injected i.v. into the tail produced local metastasis in non-nude or nude NIH/Swiss mice. T4-PA cells were more widely metastatic than T3-HA cells when injected i.v. into nude mice. Evaluation of the injected mice indicated a general increase in metastatic potential of each cell line in the progression as compared to the GhrasT-NIH/3T3 transformed cells. A new photomicrographic technique to follow growth rates within six preselected 2×2mm(2) grids per plate is described. Average doubling times of the transformed cells GhrasT-NIH/3T3 (17h), T1A (17.5h), T2A (15.5h), T3-HA (17.5h) and T4-PA (18.5h) (average 17.2h) were significantly faster (P=0.006) than NIH Swiss primary embryonic cells and NIH/3T3 cells (22 h each). This cell series is currently used in this lab for studies of cancer cell inhibitors, mitochondrial biogenesis and gene expression and is available for further study by other investigators for intra- and inter-laboratory comparisons of WGS, transcriptome sequencing, SKY and other analyses. The genome rearrangements in these cells together with their phenotypic properties may help provide more insights into how one tumorigenic progression occurred to produce the various cell lines that led to the highly metastatic T4-PA cell line.

Suba Z
DNA stabilization by the upregulation of estrogen signaling in BRCA gene mutation carriers.
Drug Des Devel Ther. 2015; 9:2663-75 [PubMed] Free Access to Full Article Related Publications
Currently available scientific evidence erroneously suggests that mutagenic weakness or loss of the BRCA1/2 genes may liberate the proliferative effects of estrogen signaling, which provokes DNA damage and genomic instability. Conversely, BRCA mutation seems to be an imbalanced defect, crudely inhibiting the upregulation of estrogen receptor expression and liganded transcriptional activity, whereas estrogen receptor-repressor functions become predominant. In BRCA-proficient cases, estrogen signaling orchestrates the activity of cell proliferation and differentiation with high safety, while upregulating the expression and DNA-stabilizing impact of BRCA genes. In turn, BRCA proteins promote estrogen signaling by proper estrogen synthesis via CYP19 gene regulation and by induction of the appropriate expression and transcriptional activity of estrogen receptors. In this exquisitely organized regulatory system, the dysfunction of each player may jeopardize genome stability and lead to severe chronic diseases, such as cancer development. Female organs, such as breast, endometrium, and ovary, exhibiting regular cyclic proliferative activity are particularly vulnerable in case of disturbances in either estrogen signaling or BRCA-mediated DNA repair. BRCA mutation carrier women may apparently be healthy or exhibit clinical signs of deficient estrogen signaling in spite of hyperestrogenism. Even women who enjoy sufficient compensatory DNA-defending activities are at risk of tumor development because many endogenous and environmental factors may jeopardize the mechanisms of extreme compensatory processes. Natural estrogens have numerous benefits in tumor prevention and therapy even in BRCA mutation carriers. There are no toxic effects even in sky-high doses and all physiologic cellular functions are strongly upregulated, while malignant tumor cells are recognized and killed in a Janus-faced manner.

Vouri M, An Q, Birt M, et al.
Small molecule inhibition of Axl receptor tyrosine kinase potently suppresses multiple malignant properties of glioma cells.
Oncotarget. 2015; 6(18):16183-97 [PubMed] Free Access to Full Article Related Publications
Glioblastoma multiforme (GBM) often features a combination of tumour suppressor gene inactivation and multiple oncogene overactivation. The Axl receptor tyrosine kinase is found overexpressed in GBM and thought to contribute to invasiveness, chemoresistance and poor survival. Here, we have evaluated the effect of BGB324, a clinical candidate Axl-specific small molecule inhibitor, on the invasive behaviour of human GBM cells in vitro, as an indicator of its potential in GBM therapy and also to elucidate the role of Axl in GBM pathogenesis.Two cultured adult GBM cell lines, SNB-19 and UP007, were treated with Gas6 and/or BGB324, and analysed in assays for survival, 3D colony growth, motility, migration and invasion. Western blot was used to detect protein expression and signal protein phosphorylation. In both cell lines, BGB324 inhibited specifically phosphorylation of Axl as well as Akt kinase further downstream. BGB324 also inhibited survival and proliferation of both cell lines in a concentration-dependent manner, as well as completely suppressing migration and invasion. Furthermore, our results indicate co-operative activation between the Axl and Tyro3 receptors, as well as ligand-independent Axl signalling, to take place in GBM cells. In conclusion, small molecule inhibitor-led targeting of Axl may be a promising therapy for GBM progression.

Kim NY, Lee HY, Lee C
Metformin targets Axl and Tyro3 receptor tyrosine kinases to inhibit cell proliferation and overcome chemoresistance in ovarian cancer cells.
Int J Oncol. 2015; 47(1):353-60 [PubMed] Related Publications
Metformin, the most frequently prescribed anti-diabetic drug, has recently been paid attention as a chemotherapeutic agent. In this study, we demonstrated that metformin decreased the viability of parental as well as cisplatin/taxol-resistant ovarian cancer cells. Its anti-proliferative effect was further demonstrated by dose‑dependent reduction of the clonogenic ability of the metformin‑treated cells. We next observed the effect of metformin on expression of Axl and Tyro3 receptor tyrosine kinases (RTKs) which belong to the TAM subfamily of RTKs transducing pro-survival and anti-apoptotic signals. Metformin treatment of ovarian cancer cells decreased both mRNA and protein levels of Axl and Tyro3 in a dose‑dependent manner. Axl promoter activity was also inhibited by metformin, indicating that metformin suppresses Axl and Tyro3 expression at the transcriptional level. Metformin treatment was also found to augment its anti‑proliferative effect in SKOV3 and taxol-resistant SKOV3/TR cells transfected with Axl and Tyro3 specific siRNAs, siAxl and siTyro3, respectively, suggesting that metformin might target Axl and Tyro3 RTKs to restrain cell proliferation. In parallel, the level of X-linked inhibitor of apoptosis protein (XIAP), an anti-apoptotic molecule, was reduced in the metformin-treated cells. Collectively, our data showed that metformin caused reduction of Axl and Tyro3 RTKs' expression, inactivation of downstream effectors, and decrease of anti-apoptotic protein level, forming a potent therapeutic strategy to facilitate its anticancer activity as well as to overcome chemoresistance in human ovarian cancer cells.

Lee C
Overexpression of Tyro3 receptor tyrosine kinase leads to the acquisition of taxol resistance in ovarian cancer cells.
Mol Med Rep. 2015; 12(1):1485-92 [PubMed] Related Publications
The majority of patients with ovarian cancer are diagnosed at the advanced stages (III/IV) and their 5-year-survival rate is relatively low. One of the major causes of the poor prognosis of ovarian cancer is the development of resistance to first-line chemotherapy, including platinum and taxol. Therefore, improvements in current understanding of chemoresistance is required for the successful treatment of ovarian cancer. In the present study, taxol-resistant ovarian cancer cells, SKOV3/TR, were established by exposing parental SKOV3 cells to increasing concentrations of taxol. . Briefly, cells were treated with 1.5 nM (for 4 weeks), 3 nM (for 4 weeks), 6 nM (for 5 weeks), 12 nM (for 5 weeks) and 24 nM taxol (for 8 weeks) over 6 months. The SKOV3/TR cells were found to be smaller in size and rounder in shape compared with their parental cells. Cell viability and colony formation assays demonstrated an increase in the population doubling time of the SKOV3/TR cells, indicating a reduction in the proliferative capacity of these cells. Reverse transcription-polymerase chain reaction and western blot analysis revealed that, among the TAM receptor tyrosine kinases (RTKs), the mRNA and protein expression levels of Tyro3 RTK were increased, while those of Axl and Mer RTK were decreased in the SKOV3/TR cells. In addition, restoration of the level of Tyro3 by transfecting Tyro3-specific small interfering RNA into the SKOV3/TR cells reduced the proliferative capacity of the cells, indicating that upregulation of the expression of Tyro3 in SKOV3/TR cells may promote survival in the presence of taxol, which eventually resulted in the acquisition of resistance upon taxol treatment. The present study subsequently found that, in the SKOV3/TR cells, the level of intracellular reactive oxygen species (ROS) was elevated, and antioxidant treatment with N-acetyl cysteine (NAC) exerted more profound antiproliferative effects compared with the parental cells. The western blot analysis demonstrated that treatment of the SKOV3/TR cells with NAC reduced the protein expression of Tyro3, and the inhibitory effect of NAC on the phosphorylation of Akt was increased, which may have had a positive effect on the proliferation of the SKOV3/TR cells. The levels of phosphorylation and protein expression of signal transducers and activators of transcription 3 (STAT3) were not affected by NAC treatment, indicating that the phosphorylation of Akt, but not expression or phosphorylation of STAT3, was associated with the increased intracellular ROS level in the SKOV3/TR cells. Taken together, the results of the present study demonstrated that the acquired taxol resistance of ovarian cancer cells was associated with ROS-dependent upregulation in the expression of Tyro3 RTK and the subsequent activation of Akt.

Janning M, Ben-Batalla I, Loges S
Axl inhibition: a potential road to a novel acute myeloid leukemia therapy?
Expert Rev Hematol. 2015; 8(2):135-8 [PubMed] Related Publications
Novel treatment options in acute myeloid leukemia (AML) are urgently needed; treatment has not changed significantly over the past decades and survival is still dismal, especially in elderly patients. Axl, a member of the Tyro3, Axl, Mer (TAM) receptor family, mediates proliferation and survival of AML cells and is upregulated upon cytostatic treatment. In addition, AML cells induce expression of the Axl ligand growth arrest-specific gene 6 (Gas6) in bone marrow stroma cells, which further amplifies their growth and therapy resistance. Interruption of Axl signaling by pharmacological approaches, including the small molecule Axl inhibitor BGB324, decreased disease burden and prolonged survival of AML mice. The Gas6-Axl pathway has translational relevance because Axl is expressed by approximately 50% of AML patients and Axl-targeting approaches can block growth of primary human AML cells. Thus, Axl represents a potential novel target in AML and BGB324 is now in clinical development.

Ehrlich LA, Yang-Iott K, Bassing CH
Tcrδ translocations that delete the Bcl11b haploinsufficient tumor suppressor gene promote atm-deficient T cell acute lymphoblastic leukemia.
Cell Cycle. 2014; 13(19):3076-82 [PubMed] Free Access to Full Article Related Publications
ATM is the master regulator of the cellular response to DNA double strand breaks (DSBs). Deficiency of ATM predisposes humans and mice to αβ T lymphoid cancers with clonal translocations between the T cell receptor (TCR) α/δ locus and a 450 kb region of synteny on human chromosome 14 and mouse chromosome 12. While these translocations target and activate the TCL1 oncogene at 14q32 to cause T cell pro-lymphocytic leukemia (T-PLL), the TCRα/δ;14q32 translocations in ATM-deficient T cell acute lymphoblastic leukemia (T-ALL) have not been characterized and their role in cancer pathogenesis remains unknown. The corresponding lesion in Atm-deficient mouse T-ALLs is a chromosome t(12;14) translocation with Tcrδ genes fused to sequences on chromosome 12; although these translocations do not activate Tcl1, they delete the Bcl11b haploinsufficient tumor suppressor gene. To assess whether Tcrδ translocations that inactivate one copy of Bcl11b promote transformation of Atm-deficient cells, we analyzed Atm(-/-) mice with mono-allelic Bcl11b deletion initiating in thymocytes concomitant with Tcrδ recombination. Inactivation of one Bcl11b copy had no effect on the predisposition of Atm(-/-) mice to clonal T-ALLs. Yet, none of these T-ALLs had a clonal chromosome t(12;14) translocation that deleted Bcl11b indicating that Tcrδ translocations that inactivate a copy of Bcl11b promote transformation of Atm-deficient thymocytes. Our data demonstrate that antigen receptor locus translocations can cause cancer by deleting a tumor suppressor gene. We discuss the implications of these findings for the etiology and therapy of T-ALLs associated with ATM deficiency and TCRα/δ translocations targeting the 14q32 cytogenetic region.

Krause S, Pfeiffer C, Strube S, et al.
Mer tyrosine kinase promotes the survival of t(1;19)-positive acute lymphoblastic leukemia (ALL) in the central nervous system (CNS).
Blood. 2015; 125(5):820-30 [PubMed] Related Publications
Patients with t(1;19)-positive acute lymphoblastic leukemia (ALL) are prone to central nervous system (CNS) relapses, and expression of the TAM (Tyro3, Axl, and Mer) receptor Mer is upregulated in these leukemias. We examined the functional role of Mer in the CNS in preclinical models and performed correlative studies in 64 t(1;19)-positive and 93 control pediatric ALL patients. ALL cells were analyzed in coculture with human glioma cells and normal rat astrocytes: CNS coculture caused quiescence and protection from methotrexate toxicity in Mer(high) ALL cell lines, which was antagonized by short hairpin RNA-mediated knockdown of Mer. Mer expression was upregulated, prosurvival Akt and mitogen-activated protein kinase signaling were activated, and secretion of the Mer ligand Galectin-3 was stimulated. Mer(high) t(1;19) primary cells caused CNS involvement to a larger extent in murine xenografts than in their Mer(low) counterparts. Leukemic cells from Mer(high) xenografts showed enhanced survival in coculture. Treatment of Mer(high) patient cells with the Mer-specific inhibitor UNC-569 in vivo delayed leukemia onset, reduced CNS infiltration, and prolonged survival of mice. Finally, a correlation between high Mer expression and CNS positivity upon initial diagnosis was observed in t(1;19) patients. Our data provide evidence that Mer is associated with survival in the CNS in t(1;19)-positive ALL, suggesting a role as a diagnostic marker and therapeutic target.

Xu LX, Holland H, Kirsten H, et al.
Three gangliogliomas: results of GTG-banding, SKY, genome-wide high resolution SNP-array, gene expression and review of the literature.
Neuropathology. 2015; 35(2):148-57 [PubMed] Related Publications
According to the World Health Organization gangliogliomas are classified as well-differentiated and slowly growing neuroepithelial tumors, composed of neoplastic mature ganglion and glial cells. It is the most frequent tumor entity observed in patients with long-term epilepsy. Comprehensive cytogenetic and molecular cytogenetic data including high-resolution genomic profiling (single nucleotide polymorphism (SNP)-array) of gangliogliomas are scarce but necessary for a better oncological understanding of this tumor entity. For a detailed characterization at the single cell and cell population levels, we analyzed genomic alterations of three gangliogliomas using trypsin-Giemsa banding (GTG-banding) and by spectral karyotyping (SKY) in combination with SNP-array and gene expression array experiments. By GTG and SKY, we could confirm frequently detected chromosomal aberrations (losses within chromosomes 10, 13 and 22; gains within chromosomes 5, 7, 8 and 12), and identify so far unknown genetic aberrations like the unbalanced non-reciprocal translocation t(1;18)(q21;q21). Interestingly, we report on the second so far detected ganglioglioma with ring chromosome 1. Analyses of SNP-array data from two of the tumors and respective germline DNA (peripheral blood) identified few small gains and losses and a number of copy-neutral regions with loss of heterozygosity (LOH) in germline and in tumor tissue. In comparison to germline DNA, tumor tissues did not show substantial regions with significant loss or gain or with newly developed LOH. Gene expression analyses of tumor-specific genes revealed similarities in the profile of the analyzed samples regarding different relevant pathways. Taken together, we describe overlapping but also distinct and novel genetic aberrations of three gangliogliomas.

Waizenegger JS, Ben-Batalla I, Weinhold N, et al.
Role of Growth arrest-specific gene 6-Mer axis in multiple myeloma.
Leukemia. 2015; 29(3):696-704 [PubMed] Related Publications
Multiple myeloma is a mostly incurable malignancy characterized by the expansion of a malignant plasma cell (PC) clone in the human bone marrow (BM). Myeloma cells closely interact with the BM stroma, which secretes soluble factors that foster myeloma progression and therapy resistance. Growth arrest-specific gene 6 (Gas6) is produced by BM-derived stroma cells and can promote malignancy. However, the role of Gas6 and its receptors Axl, Tyro3 and Mer (TAM receptors) in myeloma is unknown. We therefore investigated their expression in myeloma cell lines and in the BM of myeloma patients and healthy donors. Gas6 showed increased expression in sorted BMPCs of myeloma patients compared with healthy controls. The fraction of Mer(+) BMPCs was increased in myeloma patients in comparison with healthy controls whereas Axl and Tyro3 were not expressed by BMPCs in the majority of patients. Downregulation of Gas6 and Mer inhibited the proliferation of different myeloma cell lines, whereas knocking down Axl or Tyro3 had no effect. Inhibition of the Gas6 receptor Mer or therapeutic targeting of Gas6 by warfarin reduced myeloma burden and improved survival in a systemic model of myeloma. Thus, the Gas6-Mer axis represents a novel candidate for therapeutic intervention in this incurable malignancy.

Nguyen KQ, Tsou WI, Calarese DA, et al.
Overexpression of MERTK receptor tyrosine kinase in epithelial cancer cells drives efferocytosis in a gain-of-function capacity.
J Biol Chem. 2014; 289(37):25737-49 [PubMed] Free Access to Full Article Related Publications
MERTK, a member of the TAM (TYRO3, AXL, and MERTK) receptor tyrosine kinases, has complex and diverse roles in cell biology. On the one hand, knock-out of MERTK results in age-dependent autoimmunity characterized by failure of apoptotic cell clearance, while on the other, MERTK overexpression in cancer drives classical oncogene pathways leading to cell transformation. To better understand the interplay between cell transformation and efferocytosis, we stably expressed MERTK in human MCF10A cells, a non-tumorigenic breast epithelial cell line devoid of endogenous MERTK. While stable expression of MERTK in MCF10A resulted in enhanced motility and AKT-mediated chemoprotection, MERTK-10A cells did not form stable colonies in soft agar, or enhance proliferation compared with parental MCF10A cells. Concomitant to chemoresistance, MERTK also stimulated efferocytosis in a gain-of-function capacity. However, unlike AXL, MERTK activation was highly dependent on apoptotic cells, suggesting MERTK may preferentially interface with phosphatidylserine. Consistent with this idea, knockdown of MERTK in breast cancer cells MDA-MB 231 reduced efferocytosis, while transient or stable expression of MERTK stimulated apoptotic cell clearance in all cell lines tested. Moreover, human breast cancer cells with higher endogenous MERTK showed higher levels of efferocytosis that could be blocked by soluble TAM receptors. Finally, through MERTK, apoptotic cells induced PD-L1 expression, an immune checkpoint blockade, suggesting that cancer cells may adopt MERTK-driven efferocytosis as an immune suppression mechanism for their advantage. These data collectively identify MERTK as a significant link between cancer progression and efferocytosis, and a potentially unrealized tumor-promoting event when MERTK is overexpressed in epithelial cells.

Ekyalongo RC, Mukohara T, Funakoshi Y, et al.
TYRO3 as a potential therapeutic target in breast cancer.
Anticancer Res. 2014; 34(7):3337-45 [PubMed] Related Publications
AIM: We evaluated the potential of TYRO3 as a therapeutic target in various types of breast cancer cell lines.
MATERIALS AND METHODS: The effects of TYRO3-knockdown by small interfering RNA (siRNA) on proliferation, cell-cycle distribution, and cell signaling in four estrogen receptor (ER)-positive/HER2-non-amplified (luminal-type), two ER-negative/HER2-amplified (HER2-type), and two ER-negative/HER2-non-amplified (triple negative [TN]-type) cell lines were compared.
RESULTS: Whereas TYRO3 knockdown induced the greatest proliferation suppression in luminal-type cells, and to a lesser extent in HER2-type cells, no proliferation inhibition was observed in TN-type cells. The TYRO3 siRNA-induced proliferation inhibition in luminal-type cells was observed in both estradiol (E2)-rich and -null conditions. The proliferation suppression was correlated with G0-G1/S cell-cycle arrest. Western blot analysis showed a decrease in phosphorylation of ERK1/2 or STAT3, and in cyclin D1 only in cell lines sensitive to TYRO3-knockdown.
CONCLUSION: TYRO3 is a potential therapeutic target in breast cancer, particularly in luminal-type cells.

Milione M, Gasparini P, Sozzi G, et al.
Ewing sarcoma of the small bowel: a study of seven cases, including one with the uncommonly reported EWSR1-FEV translocation.
Histopathology. 2014; 64(7):1014-26 [PubMed] Related Publications
AIMS: Primary Ewing sarcoma of the ileum has rarely been documented. Little is known about its pathogenesis and clinical implications, and it would be helpful to identify novel molecular markers. EWSR1-FEV translocation is exceedingly rare in Ewing sarcoma, as FEV expression is restricted to prostate, brain and serotonin neuroendocrine cells (NE) and related tumours.
METHODS AND RESULTS: Paraffin sections or snap-frozen material were used in this investigation. Tumours were investigated by means of immunohistochemistry, RT-PCR (EWSR1-FLI1, EWSR1-ERG and EWSR1-FEV transcripts), FISH analysis (EWSR1 break-apart and specific EWSR1-FEV translocation) and spectral karyotyping (SKY). Ten ileal neuroendocrine tumours (INET) made up the control group for EWSR1-FEV translocation. Among 445 Ewing sarcomas cases spanning a period of 20 years, seven (1.6%) arose in the ileum. All tumours were immunoreactive for synaptophysin, CD99, FLI1 and vimentin. FISH identified EWSR1 rearrangement in all cases, with EWSR1-FLI1 transcripts being detected in all but one tumour showing the uncommon EWSR1-FEV rearrangement, with SKY, RT-PCR and FISH confirmation. The mean survival of EWSR1-FLI1 patients was 14 months, whereas the EWSR1-FEV patient was alive after 15 years despite several recurrences controlled by surgery alone. No INET showed EWSR1 translocation.
CONCLUSIONS: Most primary Ewing sarcomas of the ileum show the common EWSR1-FLI1 translocation, but EWSR1-FEV could be specific for tumours arising in the ileum and showing better prognosis.

Rothlin CV, Leighton JA, Ghosh S
Tyro3, Axl, and Mertk receptor signaling in inflammatory bowel disease and colitis-associated cancer.
Inflamm Bowel Dis. 2014; 20(8):1472-80 [PubMed] Free Access to Full Article Related Publications
Three receptor tyrosine kinases, Tyro3, Axl, and Mertk (TAM) and their ligands Gas6 and Protein S, have emerged as potent negative regulators of innate immune responses. A number of studies using genetic ablation of TAM loci in mice have elucidated the mechanism of TAM engagement and function during the immune response and removal of apoptotic cells. Following phagocytosis of apoptotic cells or the induction of T-cell dependent adaptive immune responses, ligand-induced TAM signaling dampens proinflammatory cytokine production and thus prevents exaggerated or prolonged inflammation. It is believed that the TAM pathway may play an important role in the pathogenesis of inflammatory bowel disease. Suppression of inflammation and removal of apoptotic cells followed by tissue repair are essential processes for disease remission and the successful management of inflammatory bowel disease. In light of the key role of TAMs in controlling inflammatory responses, here, we review the recent advances on TAM research vis-à-vis the resolution of intestinal inflammation. Targeted activation of TAM receptor tyrosine kinases may represent a potent therapeutic opportunity in inflammatory bowel disease.

Ho HK, Chua BT, Wong W, et al.
Benzylidene-indolinones are effective as multi-targeted kinase inhibitor therapeutics against hepatocellular carcinoma.
Mol Oncol. 2014; 8(7):1266-77 [PubMed] Related Publications
Effective pharmacological intervention of advanced hepatocellular carcinoma (HCC) is currently lacking. Despite the use of tyrosine kinase inhibitors (TKIs) for the targeted therapy of several malignancies, no agent has been developed to specifically interfere with the oncogenic tyrosine kinase signaling aberrations found in HCC. Therefore, we adopted an orthogonal biological phenotypic screening approach to uncover candidate compounds: based on a potent cytotoxicity toward HCC-derived cell lines, and minimal toxicity toward normal liver cells. Given the success of indolinone as a chemical scaffold in deriving potent multi-kinase inhibitors (e.g. sunitinib), we screened a group of newly synthesized benzylidene-indolinones. Among the candidates, E/Z 6-Chloro-3-(3-trifluoromethyl-benzyliden)-1,3-dihydroindol-2-one (compound 47) exhibited potent anti-proliferative, anti-migratory, pro-apoptotic properties and good safety profile as compared to known multi-targeted tyrosine kinase inhibitors sunitinib and sorafenib. Additionally, an accompanying suppression of alpha-fetoprotein (AFP) transcription, an HCC tumor marker, implies a favorable selectivity and efficacy on HCC. The in vivo efficacy was demonstrated in an HCC xenograft where 47 was administered once weekly (60 mg/kg) and suppressed tumor burden to the same extent as sorafenib (30 mg/kg daily). A receptor tyrosine kinase (RTK) array study revealed promising inhibition of multiple tyrosine kinases such as IGF-1R, Tyro3 and EphA2 phosphorylation. Gene silencing of these targets ameliorated the cytotoxic potential of 47 on the HuH7 cell line, thereby implicating their contribution to the tumorigenicity of HCC. Hence, 47 exhibits potent anti-cancer effects on HCC cell lines, and is a suitable lead for developing multi-targeted kinase inhibitors of relevance to HCC.

Said J, Lones M, Yea S
Burkitt lymphoma and MYC: what else is new?
Adv Anat Pathol. 2014; 21(3):160-5 [PubMed] Related Publications
Burkitt lymphoma (BL) is the most common non-Hodgkin lymphoma in children and adolescents, but at least 30% of cases occur in patients older than 60 years, and the absolute number of BL cases in adults exceeds those in childhood. BL is described as a monomorphic proliferation of medium-sized transformed B cells with round nuclei, clumped chromatin, basophilic cytoplasm, and squared-off cell borders, cytoplasmic vacuoles, medium-sized paracentral nucleoli, and a starry sky pattern. Translocation involving MYC is characteristic but not specific for BL. No single parameter is the gold standard for diagnosis; morphology, cytogenetics, immunophenotype, and gene expression profiles all may contribute to the diagnosis. Although neither EBV nor MYC are sufficient to cause BL there is increasing information from techniques such as complete RNA sequencing that identify essential pathways that are activated in the pathogenesis of BL. These findings suggest novel opportunities for improved therapeutic intervention.

de Oliveira FM, Rodrigues-Alves AP, Lucena-Araújo AR, et al.
Mantle cell lymphoma harboring Burkitt's-like translocations presents differential expression of aurora kinase genes compared with others 8q abnormalities.
Med Oncol. 2014; 31(5):931 [PubMed] Related Publications
We compared the levels of AURKA and AURKB in 24 (mantle cell lymphoma) MCL patients harboring 8q abnormalities and its relationship with MYCC gene status. Two distinct subgroups were observed, in terms of MYCC expression. Except for the patients with Burkitt's-like translocation, none of the patients harboring 8q abnormalities, including balanced translocations or duplications of MYCC band, identified both by G-banding and SKY, showed differential expression levels of MYCC. These previous findings also reflected in the differential expression of AURKA and AURKB genes. We found that AURKA and AURKB mRNA were expressed at significantly higher levels in MCL patients harboring Burkitt's-like translocation, when compared to patients with 8q rearrangements. The high expression of aurora kinase genes is reported to be associated with some parameters of clinical oncologic aggressiveness, such as high histological grade, invasion and increased rates of metastasis in several types of cancers. It is possible that in MCL patients expressing abnormal levels of MYCC together with a high expression of AURKA might offer some resistant to the conventional therapy purposes. Thus, aurora kinase inhibitors may also be considered for this specific subgroup on MCL, whose aggressive clinical course resembles high-grade lymphoma.

Weaver DA, Nestor-Kalinoski AL, Craig K, et al.
Corrections for mRNA extraction and sample normalization errors find increased mRNA levels may compensate for cancer haplo-insufficiency.
Genes Chromosomes Cancer. 2014; 53(2):194-210 [PubMed] Free Access to Full Article Related Publications
The relative mRNA levels of differentially expressed (DE) and housekeeping (HK) genes of six aneuploid cancer lines with large-scale genomic changes identified by SNP/SKY analysis were compared with similar genes in diploid cells. The aneuploid cancer lines had heterogeneous genomic landscapes with subdiploid, diploid, and supradiploid regions and higher overall gene copy numbers compared with diploid cells. The mRNA levels of the haploid, diploid, and triploid HK genes were found to be higher after correction of easily identifiable mRNA measurement errors. Surprisingly, diploid and aneuploid HK gene mRNA levels were the same by standard expression array analyses, despite the higher copy numbers of the cancer cell HK genes. This paradoxical result proved to be due to inaccurate inputs of true intra-cellular mRNAs for analysis. These errors were corrected by analyzing the expression intensities of DE and HK genes in mRNAs extracted from equal cell numbers (50:50) of intact cancer cell and lymphocyte mixtures. Correction for both mRNA extraction/sample normalization errors and total gene copy numbers found the SUIT-2 and PC-3 cell lines' cancer genes both had ~50% higher mRNA levels per single allele than lymphocyte gene alleles. These increased mRNA levels for single transcribed cancer alleles may restore functional mRNA levels to cancer genes rendered haplo-insufficient by the genetic instability of cancer. © 2013 Wiley Periodicals, Inc.

Whitman SP, Kohlschmidt J, Maharry K, et al.
GAS6 expression identifies high-risk adult AML patients: potential implications for therapy.
Leukemia. 2014; 28(6):1252-8 [PubMed] Free Access to Full Article Related Publications
Emerging data demonstrate important roles for the TYRO3/AXL/MERTK receptor tyrosine kinase (TAM RTK) family in diverse cancers. We investigated the prognostic relevance of GAS6 expression, encoding the common TAM RTK ligand, in 270 adults (n=71 aged<60 years; n=199 aged ⩾60 years) with de novo cytogenetically normal acute myeloid leukemia (CN-AML). Patients expressing GAS6 (GAS6+), especially those aged ⩾60 years, more often failed to achieve a complete remission (CR). In all patients, GAS6+ patients had shorter disease-free (DFS) and overall (OS) survival than patients without GAS6 expression (GAS6-). After adjusting for other prognostic markers, GAS6+ predicted CR failure (P=0.02), shorter DFS (P=0.004) and OS (P=0.04). To gain further biological insights, we derived a GAS6-associated gene-expression signature (P<0.001) that in GAS6+ patients included overexpressed BAALC and MN1, known to confer adverse prognosis in CN-AML, and overexpressed CXCL12, encoding stromal cell-derived factor, and its receptor genes, chemokine (C-X-C motif) receptor 4 (CXCR4) and CXCR7. This study reports for the first time that GAS6 expression is an adverse prognostic marker in CN-AML. Although GAS6 decoy receptors are not yet available in the clinic for GAS6+ CN-AML therapy, potential alternative therapies targeting GAS6+-associated pathways, for example, CXCR4 antagonists, may be considered for GAS6+ patients to sensitize them to chemotherapy.

Lohberger B, Stuendl N, Wolf E, et al.
The novel myxofibrosarcoma cell line MUG-Myx1 expresses a tumourigenic stem-like cell population with high aldehyde dehydrogenase 1 activity.
BMC Cancer. 2013; 13:563 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Myxofibrosarcoma comprises a spectrum of malignant neoplasms withprominent myxoid stromata, cellular pleomorphism, and distinct curvilinear vascular patterns. These neoplasms mainly affect patients in the sixth to eighth decades of life and the overall 5-year survival rate is 60-70%.
METHODS: After the establishment of the novel myxofibrosarcoma cell lines MUG-Myx1, cells were characterized using short tandem repeat (STR), copy number variation (CNV), and genotype/loss-of-heterozygosity (LOH) analyses. The growth behaviour of the cells was analyzed with the xCELLigence system and an MTS assay. The tumourigenicity of MUG-Myx1 was proved in NOD/SCID mice. Additionally, a stem-like cell population with high enzymatic activity of aldehyde dehydrogenase 1 (ALDH1(high)) was isolated for the first time from myxofibrosarcoma cells using the Aldefluor® assay followed by FACS analysis.
RESULTS: The frozen primary parental tumour tissue and the MUG-Myx1 cell line showed the same STR profile at the markers D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, Amelogenin, D8S1179, TPOX, and FGY. Typically, myxofibrosarcoma gain and/or amplification was mapped to 7p21.3-q31.1, q31.1-q31.33, q33-q36.2, p21.3, p21.2, p14.1-q11.23, q31.33-q33, p21.2-p14.1, q11.23-q21.3, q36.2-q36.3, which, respectively are known to harbour tumour-associated genes, including TIF, BRAF, MLL3, SMO, and MET. Typically an LOH for myxofibrosarcoma on chr5 q21 was found. In addition, MUG-Myx1 ALDH1(high) cells showed an upregulation of the ABC transporter ABCB1 and ABCG2; higher c-Myc, E-cadherin and SOX-2 expression; and a higher potential for tumourigenicity and proliferation levels.
CONCLUSION: The new myxofibrosarcoma cell line MUG-Myx1 was established to enrich the bank of publicly available cell lines, with respect to providing comprehensive genetic and epigenetic characterization. Furthermore, because of their tumourigenicity, the cell line is also suitable for in vivo experiments.

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