ARID1a as a marker of prognosis and increased sensitivity to CDK4/6, mTOR 1/2 and Src homology region 2 phosphatase (SHP 1/2) inhibitors in breast cancer (BC).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 1082-1082 ◽  
Author(s):  
Veronica Mariotti ◽  
Howard L. McLeod ◽  
Hatem Hussein Soliman
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Sensitivity Analyses ◽  
Tissue Loss ◽  
Loss Of Function ◽  
Her2 Receptor ◽  
Luminal A ◽  
Genomic Databases ◽  
Metastatic Tissue

1082 Background: ARID1a (AT Rich Interactive Domain 1A) is part of the SWI/SNF complex, which regulates gene transcription, and is believed to be a tumor suppressor gene. Low ARID1a expression has been associated with poor prognosis in BC. The aim of this study was to explore the clinical significance of ARID1a mutation and expression loss, and its potential as a therapeutic target in BC. Methods: We analyzed publicly available genomic databases to study the clinical implication of ARID1a mutations and gene expression in BC. Results: ARID1a was mutated in ~5-7 % of BCs within TCGA/METABRIC/MSK (5511 samples), but did not show differences in frequency between histology, grade, or estrogen receptor (ER)/HER2 receptor status. MSK metastatic tissue samples had higher incidence of ARID1a mutation compared to primary tumor samples (7.6% vs 4.4%, χ2 P = 0.0073). Analysis of ARID1a in KMPLOT showed that lower gene expression was associated with worse relapse-free survival and overall survival across all BCs, but the difference was primarily in molecularly classified luminal A tumors. Mutations in ARID1a did not show an association with outcomes in TCGA/METABRIC/MSK datasets. Pathway analysis of ARID1a showed it is involved in regulating ER ligand driven signaling and interacts with targets regulated by CDK4 and mTOR activity. CancerRxgene drug sensitivity analyses on BC cell lines revealed that ARID1a mutated BC cell lines were significantly more sensitive to palbociclib, SHP1/2, and mTOR1/2 inhibitors compared to ARID1a wildtype cell lines. Conclusions: Reduced activity of ARID1a in luminal BC cells may negatively affect prognosis by altering ER signaling leading to activation of druggable resistance mechanisms, particularly in metastatic tissue. Loss of function ARID1a mutations may sensitize cancer cells to CDK4/6, mTOR1/2, and SHP1/2 inhibitors in vitro. Further research in ARID1a mutated ER+ BCs using combinations of these inhibitors is warranted.

scholarly journals TRIM27 interacts with Iκbα to promote the growth of human renal cancer cells through regulating the NF-κB pathway

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chengwu Xiao ◽  
Wei Zhang ◽  
Meimian Hua ◽  
Huan Chen ◽  
Bin Yang ◽  
...  
Keyword(s):  
Cell Lines ◽  
Prognostic Indicator ◽  
The Cancer Genome Atlas ◽  
Mrna Levels ◽  
Loss Of Function ◽  
Protein Levels ◽  
Kaplan Meier ◽  
Cancer Genome Atlas

Abstract Background The tripartite motif (TRIM) family proteins exhibit oncogenic roles in various cancers. The roles of TRIM27, a member of the TRIM super family, in renal cell carcinoma (RCC) remained unexplored. In the current study, we aimed to investigate the clinical impact and roles of TRIM27 in the development of RCC. Methods The mRNA levels of TRIM27 and Kaplan–Meier survival of RCC were analyzed from The Cancer Genome Atlas database. Real-time PCR and Western blotting were used to measure the mRNA and protein levels of TRIM27 both in vivo and in vitro. siRNA and TRIM27 were exogenously overexpressed in RCC cell lines to manipulate TRIM27 expression. Results We discovered that TRIM27 was elevated in RCC patients, and the expression of TRIM27 was closely correlated with poor prognosis. The loss of function and gain of function results illustrated that TRIM27 promotes cell proliferation and inhibits apoptosis in RCC cell lines. Furthermore, TRIM27 expression was positively associated with NF-κB expression in patients with RCC. Blocking the activity of NF-κB attenuated the TRIM27-mediated enhancement of proliferation and inhibition of apoptosis. TRIM27 directly interacted with Iκbα, an inhibitor of NF-κB, to promote its ubiquitination, and the inhibitory effects of TRIM27 on Iκbα led to NF-κB activation. Conclusions Our results suggest that TRIM27 exhibits an oncogenic role in RCC by regulating NF-κB signaling. TRIM27 serves as a specific prognostic indicator for RCC, and strategies targeting the suppression of TRIM27 function may shed light on future therapeutic approaches.

scholarly journals Long noncoding RNA LINC00941 promotes pancreatic cancer progression by competitively binding miR-335-5p to regulate ROCK1-mediated LIMK1/Cofilin-1 signaling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jie Wang ◽  
Zhiwei He ◽  
Jian Xu ◽  
Peng Chen ◽  
Jianxin Jiang
Keyword(s):  
Pancreatic Cancer ◽  
Cell Growth ◽  
Cell Lines ◽  
Cancer Progression ◽  
Noncoding Rna ◽  
Epithelial Mesenchymal Transition ◽  
Loss Of Function ◽  
Mesenchymal Transition

AbstractAn accumulation of evidence indicates that long noncoding RNAs are involved in the tumorigenesis and progression of pancreatic cancer (PC). In this study, we investigated the functions and molecular mechanism of action of LINC00941 in PC. Quantitative PCR was used to examine the expression of LINC00941 and miR-335-5p in PC tissues and cell lines, and to investigate the correlation between LINC00941 expression and clinicopathological features. Plasmid vectors or lentiviruses were used to manipulate the expression of LINC00941, miR-335-5p, and ROCK1 in PC cell lines. Gain or loss-of-function assays and mechanistic assays were employed to verify the roles of LINC00941, miR-335-5p, and ROCK1 in PC cell growth and metastasis, both in vivo and in vitro. LINC00941 and ROCK1 were found to be highly expressed in PC, while miR-335-5p exhibited low expression. High LINC00941 expression was strongly associated with larger tumor size, lymph node metastasis, and poor prognosis. Functional experiments revealed that LINC00941 silencing significantly suppressed PC cell growth, metastasis and epithelial–mesenchymal transition. LINC00941 functioned as a molecular sponge for miR-335-5p, and a competitive endogenous RNA (ceRNA) for ROCK1, promoting ROCK1 upregulation, and LIMK1/Cofilin-1 pathway activation. Our observations lead us to conclude that LINC00941 functions as an oncogene in PC progression, behaving as a ceRNA for miR-335-5p binding. LINC00941 may therefore have potential utility as a diagnostic and treatment target in this disease.

scholarly journals Gene Transfer into the Lung by Nanoparticle Dextran-Spermine/Plasmid DNA Complexes

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Syahril Abdullah ◽  
Wai Yeng Wendy-Yeo ◽  
Hossein Hosseinkhani ◽  
Mohsen Hosseinkhani ◽  
Ehab Masrawa ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gene Transfer ◽  
Cell Lines ◽  
Plasmid Dna ◽  
Mixing Ratio ◽  
Systemic Delivery ◽  
Clear Trend ◽  
Assay Time

A novel cationic polymer, dextran-spermine (D-SPM), has been found to mediate gene expression in a wide variety of cell lines andin vivothrough systemic delivery. Here, we extended the observations by determining the optimal conditions for gene expression of D-SPM/plasmid DNA (D-SPM/pDNA) in cell lines and in the lungs of BALB/c mice via instillation delivery.In vitrostudies showed that D-SPM could partially protect pDNA from degradation by nuclease and exhibited optimal gene transfer efficiency at D-SPM to pDNA weight-mixing ratio of 12. In the lungs of mice, the levels of gene expression generated by D-SPM/pDNA are highly dependent on the weight-mixing ratio of D-SPM to pDNA, amount of pDNA in the complex, and the assay time postdelivery. Readministration of the complex at day 1 following the first dosing showed no significant effect on the retention and duration of gene expression. The study also showed that there was a clear trend of increasing size of the complexes as the amount of pDNA was increased, where the sizes of the D-SPM/pDNA complexes were within the nanometer range.

scholarly journals Analysis of the Gene Expression Profile of Stromal Pro-Tumor Factors in Cancer-Associated Fibroblasts from Luminal Breast Carcinomas

Diagnostics ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 865 ◽  
Author(s):  
Noemi Eiro ◽  
Sandra Cid ◽  
María Fraile ◽  
Jorge Ruben Cabrera ◽  
Luis O. Gonzalez ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Cell Lines ◽  
Cancer Cell ◽  
Cancer Cell Lines ◽  
Breast Cancer Cell Lines ◽  
Cancer Associated Fibroblasts ◽  
Breast Carcinomas ◽  
Luminal A ◽  
Luminal B

Luminal tumors are the most frequent type of breast carcinomas showing less tumor aggressiveness, although heterogeneity exists in their clinical outcomes. Cancer-associated fibroblasts (CAFs) are a key component of the tumor stroma which contribute to tumor progression. We investigated by real-time PCR the gene expression of 19 factors implicated in tumor progression. Those factors included the calcium-binding protein S100A4, several growth factors (FGF2, FGF7, HGF, PDGFA, PDGFB, TGFβ, VEGFA, and IGF2), and we also studied inflammatory cytokines (IL6 and IL8), chemokines (CCL2, CXCL12), important proteases (uPA, MMP2, MMP9 and MMP11), the nuclear factor NFκB, and the metalloprotease inhibitor TIMP1, from luminal A and luminal B breast carcinoma CAFs. We performed a similar analysis after co-culturing CAFs with MCF-7 and MDA-MB-231 breast cancer cell lines. MMP-9 and CCL2 gene expressions were higher in CAFs from luminal B tumors. We also found different patterns in the induction of pro-tumoral factors from different CAFs populations co-cultured with different cancer cell lines. Globally, CAFs from luminal B tumors showed a higher expression of pro-tumor factors compared to CAFs from luminal A tumors when co-cultured with breast cancer cell lines. Moreover, we found that CAFs from metastatic tumors had higher IGF-2 gene expression, and we detected the same after co-culture with cell lines. Our results show the variability in the capacities of CAFs from luminal breast carcinomas, which may contribute to a better biological and clinical characterization of these cancer subtypes.

CDK12 inhibition mediates DNA damage and is synergistic with sorafenib treatment in hepatocellular carcinoma

Gut ◽  
2019 ◽  
Vol 69 (4) ◽  
pp. 727-736 ◽  
Author(s):  
Cun Wang ◽  
Hui Wang ◽  
Cor Lieftink ◽  
Aimee du Chatinier ◽  
Dongmei Gao ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Dna Damage ◽  
Cell Lines ◽  
Synergistic Effects ◽  
Loss Of Function ◽  
Bioinformatics Analyses ◽  
Sorafenib Treatment ◽  
Hcc Cells

ObjectivesHepatocellular carcinoma (HCC) is one of the most frequent malignancies and a major leading cause of cancer-related deaths worldwide. Several therapeutic options like sorafenib and regorafenib provide only modest survival benefit to patients with HCC. This study aims to identify novel druggable candidate genes for patients with HCC.DesignA non-biased CRISPR (clustered regularly interspaced short palindromic repeats) loss-of-function genetic screen targeting all known human kinases was performed to identify vulnerabilities of HCC cells. Whole-transcriptome sequencing (RNA-Seq) and bioinformatics analyses were performed to explore the mechanisms of the action of a cyclin-dependent kinase 12 (CDK12) inhibitor in HCC cells. Multiple in vitro and in vivo assays were used to study the synergistic effects of the combination of CDK12 inhibition and sorafenib.ResultsWe identify CDK12 as critically required for most HCC cell lines. Suppression of CDK12 using short hairpin RNAs (shRNAs) or its inhibition by the covalent small molecule inhibitor THZ531 leads to robust proliferation inhibition. THZ531 preferentially suppresses the expression of DNA repair-related genes and induces strong DNA damage response in HCC cell lines. The combination of THZ531 and sorafenib shows striking synergy by inducing apoptosis or senescence in HCC cells. The synergy between THZ531 and sorafenib may derive from the notion that THZ531 impairs the adaptive responses of HCC cells induced by sorafenib treatment.ConclusionOur data highlight the potential of CDK12 as a drug target for patients with HCC. The striking synergy of THZ531 and sorafenib suggests a potential combination therapy for this difficult to treat cancer.

Cell-specific posttranscriptional regulation of CFTR gene expression via influence of MAPK cascades on 3′UTR part of transcripts

2005 ◽  
Vol 289 (5) ◽  
pp. C1240-C1250 ◽  
Author(s):  
Maryvonne Baudouin-Legros ◽  
Alexandre Hinzpeter ◽  
Amandine Jaulmes ◽  
Franck Brouillard ◽  
Bruno Costes ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Posttranscriptional Regulation ◽  
P38 Map Kinase ◽  
Cftr Gene ◽  
Control Of Gene Expression ◽  
Cytosolic Proteins ◽  
Tnf Α ◽  
Ht 29

Expression of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene, which contains the mutations responsible for CF, is regulated by cytokines (TNF-α and IL-1β) in a cell-specific manner. TNF-α decreases CFTR mRNA in human colon cell lines (HT-29), but not in pulmonary cell lines (Calu-3), and IL-1β increases it only in Calu-3 cells. We looked for the cytokine-induced posttranscriptional regulation of CFTR gene expression and studied the modulation of CFTR mRNA stability linked to its 3′ untranslated sequence (3′UTR) in HT-29 and Calu-3 cells. The stability of CFTR mRNA was analyzed by Northern blot after in vitro incubation of total RNAs from CFTR-expressing cells with cytosolic proteins extracted from control or cytokine-treated HT-29 and Calu-3 cells. CFTR mRNA was degraded only by extracts of TNF-α-treated HT-29 cells and not by cytosolic proteins from untreated or IL-1β-treated HT-29 cells. In contrast, extracts of untreated Calu-3 cells enhanced CFTR mRNA degradation, and IL-1β treatment inhibited this; TNF-α had no significant effect. The 3′UTR part of CFTR mRNA was found to be required for this posttranscriptional regulation. The 5′ part of the 3′UTR (the 217 first bases), which contains two AUUUA sequences, was implicated in CFTR mRNA destabilization and the following 136 bases, containing several C-repeats in U-rich environment, in its protection. The proteins, which reacted with the U- and C-repeats of CFTR mRNA 3′UTR, were mainly controlled by stimulation of the p42/p44 and p38 MAP kinase cascades with interaction between these pathways. This posttranscriptional control of gene expression is a common feature of CFTR and many proteins of inflammation.

scholarly journals Tumorigenicity of simian virus 40-hepatocyte cell lines: effect of in vitro and in vivo passage on expression of liver-specific genes and oncogenes.

1988 ◽  
Vol 8 (10) ◽  
pp. 4492-4501 ◽  
Author(s):  
C D Woodworth ◽  
J W Kreider ◽  
L Mengel ◽  
T Miller ◽  
Y L Meng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Tumor Cell ◽  
Cell Lines ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Tumor Cell Lines ◽  
Glutathione S Transferase

Five simian virus 40 (SV40)-hepatocyte cell lines were examined for tumorigenicity and the effect of in vitro passage on the expression of four liver-specific genes (albumin, transferrin, alpha 1-antitrypsin, and phosphoenolpyruvate carboxykinase), two oncogenes (c-Ha-ras and c-raf), and two genes associated with hepatocarcinogenesis (alpha-fetoprotein and placental-type glutathione-S-transferase). At low passage (12 to 22), all five cell lines expressed the four liver-specific genes at levels similar to those in the liver and were not tumorigenic or were weakly tumorigenic. At high passage (33 to 61), the cell lines formed carcinomas, and four out of five cell lines produced primary tumors that metastasized. At least two cell lines produced well-differentiated hepatocellular carcinomas that expressed liver-specific RNAs. Levels of expression of liver-specific genes changed with time in culture. Some of the changes in liver-specific gene expression in the tumor tissue (such as for the phosphoenolpyruvate carboxykinase gene) paralleled those that occurred with in vitro passage, while other changes (such as for the albumin gene) did not parallel those that occurred with in vitro passage. Correlations between enhanced expression of c-Ha-ras and tumorigenic potential and between the process of SV40 immortalization and induced expression of c-raf and glutathione-S-transferase-P were observed. Induction of alpha-fetoprotein was detected with in vitro and in vivo passage only in the CWSV14 cell line and was paralleled by diminished albumin expression. In conclusion, we developed a model system with five SV40-hepatocyte cell lines, tumors induced by them, and tumor cell lines to examine changes in gene expression that accompany the progression from a normal cell to a hepatocellular carcinoma. Because the SV40-hepatocyte cell lines and tumor cell lines remain highly differentiated and vary in the magnitude of expression of specific genes, they can be used to study the molecular mechanisms regulating gene expression, in particular those regulating specific genes associated with differentiation.

Preclinical Investigations Demonstrate Effectiveness of Aplidin in Acute Leukemias and Lymphomas and Provide the Basis for Further Clinical Studies.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4496-4496
Author(s):  
Debabrata Banerjee ◽  
Guray Saydam ◽  
Lata G. Menon ◽  
Giuseppe S.A. Longo ◽  
Daniel Medina ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Phase Ii ◽  
Myeloid Leukemia ◽  
Xenograft Model ◽  
Vascular Endothelial ◽  
Endothelial Growth Factor ◽  
Leukemias And Lymphomas

Abstract Aplidin (dehydrodidemnin B, C57H89N7O15) (APLD) is a novel antitumor agent isolated from the Mediterranean tunicate (seasquirt) Aplidium albicans. APLD has shown impressive in vitro and in vivo activity against different human cancer cells and has recently entered Phase II clinical trials in a variety of solid tumors following promising toxicity and pharmacological properties seen in Phase I studies. Fatigue and muscular pain were the most prevalent toxicities at 5 mg/m2 iv 3 h every other week or 3.4 mg/m2/wk with little or no bone marrow toxicity. APLD inhibits protein synthesis via GTP-dependent elongation factors 1-alpha and ornithine decarboxylase (ODC) activity, induces rapid p53-independent apoptosis in vitro, cell cycle perturbation and alteration of gene expression at early times after treatment. APLD inhibits vascular endothelial growth factor (VEGF) secretion and vascular endothelial growth factor-receptor 1 (VEGF-R1/flt-1), preventing autocrine stimulation in the human lymphoid leukemic cell line MOLT-4 cells and in AML blasts. APLD is a potent inhibitor of human myeloid leukemia cell lines (K-562, HEL and HL60), as well as fresh blast cells obtained from patients with both ALL and AML and is more potent than Idarubicin. Cytototoxic doses effective against multiple myeloma cells and fresh pediatric and adult ALL/AML blasts are achievable in plasma and are well below the recommended dose, thus a positive therapeutic index is anticipated. Moreover, the lack of cross resistance with conventional agents against fresh pediatric and adult AML/ALL blasts except fludarabine and Gemcitabine makes APLD an attractive therapeutic choice. Characterization of gene expression profile is currently underway in an attempt to generate a molecular fingerprint of sensitivity/resistance to APLD that will be validated in phase II clinical studies. Based on in vitro antileukemic effect of APLD as well as early results of clinical trials, a systematic study of drug combinations with Aplidin (APLD), for use possible in hematologic malignancies was undertaken. Three cell lines viz. K562 (acute myeloid leukemia), CCRF-CEM (acute lymphocytic leukemia), and SKI-DLCL (diffuse large cell lymphoma) were used for combination studies. Cytarabine and mitoxantrone were found to be synergistic in combination with APLD in all 3 cell lines as assessed by the Chou-Talalay combination index analysis. Since cytarabine and APLD produced impressive synergistic cell kill in all three cell culture models, the combination was further tested in the CCRF-CEM ALL xenograft model in SCID mice. APLD (0.7 mg/Kg) potentiated the antitumoral effect of cytarabine (50mg/Kg) in vivo. Addition of APLD to cytarabine treatment in xenograft model resulted in greater than 50% reduction in tumor size as compared to the untreated group. T/C ratios indicated that the effect of the combination was maximal at day 5 but was still maintained on day 8 (T/C on day 3 = 0.614; day 5= 0.403 and day 8= 0.703). The preclinical results with APLD in leukemias and lymphomas, as a single agent and in combination with cytarabine provide the basis for implementation of a phase II program in resistant relapsed leukemias and lymphomas.

In Vitro and In Vivo Monitoring of Valproic Acid Effects on Gene Expression Signatures in Adult Acute Myeloid Leukemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2605-2605
Author(s):  
Lars Bullinger ◽  
Konstanze Dohner ◽  
Richard F. Schlenk ◽  
Frank G. Rucker ◽  
Jonathan R. Pollack ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Leukemia Cell ◽  
Serum Levels ◽  
Leukemia Cell Lines ◽  
Acute Myeloid ◽  
Myeloid Leukemia Cell

Abstract Inhibitors of histone deacetylases (HDACIs) like valproic acid (VPA) display activity in murine leukemia models, and induce tumor-selective cytoxicity against blasts from patients with acute myeloid leukemia (AML). However, despite of the existing knowledge of the potential function of HDACIs, there remain many unsolved questions especially regarding the factors that determine whether a cancer cell undergoes cell cycle arrest, differentiation, or death in response to HDACIs. Furthermore, there is still limited data on HDACIs effects in vivo, as well as HDACIs function in combination with standard induction chemotherapy, as most studies evaluated HDACIs as single agent in vitro. Thus, our first goal was to determine a VPA response signature in different myeloid leukemia cell lines in vitro, followed by an in vivo analysis of VPA effects in blasts from adult de novo AML patients entered within two randomized multicenter treatment trials of the German-Austrian AML Study Group. To define an VPA in vitro “response signature” we profiled gene expression in myeloid leukemia cell lines (HL-60, NB-4, HEL-1, CMK and K-562) following 48 hours of VPA treatment by using DNA Microarray technology. In accordance with previous studies in vitro VPA treatment of myeloid cell lines induced the expression of the cyclin-dependent kinase inhibitors CDKN1A and CDKN2D coding for p21 and p19, respectively. Supervised analyses revealed many genes known to be associated with a G1 arrest. In all cell lines except for CMK we examined an up-regulation of TNFSF10 coding for TRAIL, as well as differential regulation of other genes involved in apoptosis. Furthermore, gene set enrichment analyses showed a significant down-regulation of genes involved in DNA metabolism and DNA repair. Next, we evaluated the VPA effects on gene expression in AML samples collected within the AMLSG 07-04 trial for younger (age<60yrs) and within the AMLSG 06-04 trial for older adults (age>60yrs), in which patients are randomized to receive standard induction chemotherapy (idarubicine, cytarabine, and etoposide = ICE) with or without concomitant VPA. We profiled gene expression in diagnostic AML blasts and following 48 hours of treatment with ICE or ICE/VPA. First results from our ongoing analysis of in vivo VPA treated samples are in accordance with our cell line experiments as e.g. we also see an induction of CDKN1A expression. However, the picture observed is less homogenous as concomitant administration of ICE, as well as other factors, like e.g. VPA serum levels, might substantially influence the in vivo VPA response. Nevertheless, our data are likely to provide new insights into the VPA effect in vivo, and this study may proof to be useful to predict AML patients likely to benefit from VPA treatment. To achieve this goal, we are currently analyzing additional samples, and we are planning to correlate gene expression findings with histone acetylation status, VPA serum levels, cytogenetic, and molecular genetic data.

Deregulated Apoptotic Pathways Point to Effectiveness of IAP Inhibitor Therapy in Acute Myeloid Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1275-1275
Author(s):  
Sonja C Lück ◽  
Annika C Russ ◽  
Konstanze Döhner ◽  
Ursula Botzenhardt ◽  
Domagoj Vucic ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Myeloid Leukemia ◽  
Cell Line ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Gene Set Enrichment Analysis ◽  
Core Binding Factor ◽  
Binding Factor ◽  
Acute Myeloid

Abstract Abstract 1275 Poster Board I-297 Core binding factor (CBF) leukemias, characterized by translocations t(8;21) or inv(16)/t(16;16) targeting the core binding factor, constitute acute myeloid leukemia (AML) subgroups with favorable prognosis. However, 40-50% of patients relapse, and the current classification system does not fully reflect the heterogeneity existing within the cytogenetic subgroups. Therefore, illuminating the biological mechanisms underlying these differences is important for an optimization of therapy. Previously, gene expression profiling (GEP) revealed two distinct CBF leukemia subgroups displaying significant outcome differences (Bullinger et al., Blood 2007). In order to further characterize these GEP defined CBF subgroups, we again used gene expression profiles to identify cell line models similar to the respective CBF cohorts. Treatment of these cell lines with cytarabine (araC) revealed a differential response to the drug as expected based on the expression patterns reflecting the CBF subgroups. In accordance, the cell lines resembling the inferior outcome CBF cohort (ME-1, MONO-MAC-1, OCI-AML2) were less sensitive to araC than those modeling the good prognostic subgroup (Kasumi-1, HEL, MV4-11). A previous gene set enrichment analysis had identified the pathways Caspase cascade in apoptosis and Role of mitochondria in apoptotic signaling among the most significant differentially regulated BioCarta pathways distinguishing the two CBF leukemia subgroups. Thus, we concluded that those pathways might be interesting targets for specific intervention, as deregulated apoptosis underlying the distinct subgroups should also result in a subgroup specific sensitivity to apoptotic stimuli. Therefore, we treated our model cell lines with the Smac mimetic BV6, which antagonizes inhibitor of apoptosis (IAP) proteins that are differentially expressed among our CBF cohorts. In general, sensitivity to BV6 treatment was higher in the cell lines corresponding to the subgroup with good outcome. Time-course experiments with the CBF leukemia cell line Kasumi-1 suggested a role for caspases in this response. Interestingly, combination treatment of araC and BV6 in Kasumi-1 showed a synergistic effect of these drugs, with the underlying mechanisms being currently further investigated. Based on the promising sensitivity to BV6 treatment in some cell lines, we next treated mononuclear cells (mostly leukemic blasts) derived from newly diagnosed AML patients with BV6 in vitro to evaluate BV6 potency in primary leukemia samples. Interestingly, in vitro BV6 treatment also discriminated AML cases into two distinct populations. Most patient samples were sensitive to BV6 monotherapy, but about one-third of cases were resistant even at higher BV6 dosage. GEP of BV6 sensitive patients (at 24h following either BV6 or DMSO treatment) provided insights into BV6-induced pathway alterations in the primary AML patient samples, which included apoptosis-related pathways. In contrast to the BV6 sensitive patients, GEP analyses of BV6 resistant cases revealed no differential regulation of apoptosis-related pathways in this cohort. These results provide evidence that targeting deregulated apoptosis pathways by Smac mimetics might represent a promising new therapeutic approach in AML and that GEP might be used to predict response to therapy, thereby enabling novel individual risk-adapted therapeutic approaches. Disclosures Vucic: Genentech, Inc.: Employment. Deshayes:Genentech, Inc.: Employment.

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