Gene expression profile of azacitidine- and decitabine- resistant HTLV-1-infected cell lines
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ABSTRACT: We generated azacitidine (AZA)- and decitabine (DAC)-resistant (AZA-R and DAC-R, respectively) cells from drug-sensitive ATL cell lines TL-Om1 and MT-2 via long-term drug exposure. To identify molecular mechanisms responsible for acquired resistance, we performed transcriptome analysis using Clariom S microarray.
Project description:Azacitidine (AZA) and decitabine (DAC) are cytidine azanucleoside analogs with clinical activity in myelodysplastic syndromes (MDS) and potential activity in solid tumors. To better understand the mechanism of action of these drugs, we examined the effects of AZA and DAC in a panel of non-small cell lung cancer (NSCLC) cell lines. Of 5 NSCLC lines tested in a cell viability assay, all were sensitive to AZA (EC50 of 1.8M-bM-^@M-^S10.5 M-BM-5M), while only H1299 cells were equally sensitive to DAC (EC50 of 5.1 M-BM-5M). In the relatively DAC-insensitive cell line A549, both AZA and DAC caused DNA methyltransferase I depletion and DNA hypomethylation; however, only AZA significantly induced markers of DNA damage and apoptosis, suggesting that mechanisms in addition to, or other than, DNA hypomethylation are important for AZA-induced cell death. Cell cycle analysis indicated that AZA induced an accumulation of cells in sub-G1 phase, whereas DAC mainly caused an increase of cells in G2/M. Gene expression analysis of AZA- and DAC-treated cells revealed strikingly different profiles, with many genes distinctly regulated by each drug. In summary, while both AZA and DAC caused DNA hypomethylation, distinct effects were demonstrated on regulation of gene expression, cell cycle, DNA damage, and apoptosis. A549 and H1299 cells were treated with a dose range (0.3M-bM-^@M-^S3.0 M-NM-<M) of AZA or DAC for 48 hours, and effects on gene expression were assessed by microarray analysis.
Project description:Azacitidine (AZA) and decitabine (DAC) are cytidine azanucleoside analogs with clinical activity in myelodysplastic syndromes (MDS) and potential activity in solid tumors. To better understand the mechanism of action of these drugs, we examined the effects of AZA and DAC in a panel of non-small cell lung cancer (NSCLC) cell lines. Of 5 NSCLC lines tested in a cell viability assay, all were sensitive to AZA (EC50 of 1.8–10.5 µM), while only H1299 cells were equally sensitive to DAC (EC50 of 5.1 µM). In the relatively DAC-insensitive cell line A549, both AZA and DAC caused DNA methyltransferase I depletion and DNA hypomethylation; however, only AZA significantly induced markers of DNA damage and apoptosis, suggesting that mechanisms in addition to, or other than, DNA hypomethylation are important for AZA-induced cell death. Cell cycle analysis indicated that AZA induced an accumulation of cells in sub-G1 phase, whereas DAC mainly caused an increase of cells in G2/M. Gene expression analysis of AZA- and DAC-treated cells revealed strikingly different profiles, with many genes distinctly regulated by each drug. In summary, while both AZA and DAC caused DNA hypomethylation, distinct effects were demonstrated on regulation of gene expression, cell cycle, DNA damage, and apoptosis.
Project description:Adult T-cell lymphoma/leukemia (ATL) is an aggressive subtype of leukemia/lymphoma caused by human T-cell leukemia virus type-1 (HTLV-1) and existing chemotherapy for ATL remains with extremely poor prognosis. Therefore, more effective therapeutic options are urgent needs for this disease. Since recent two clinical studies proved promising curability of Lenalidomide (LEN, a second-generation immunomodulatory drug [IMiDs]) for ATL patients, we investigated the direct growth-inhibitory machineries of LEN on ATL cells. Among 13 ATL-related cell lines, Hut102 and TL-Om1 exhibited best response to LEN treatment and LEN-induced functional modulation of E3-ubiquitin ligase cereblon (CRBN) induced degradation of hematopoietic-specific ikaros-family transcription factors IKZF1 and IKZF3 followed by suppression of their down-stream effectors IRF4 and c-Myc (both have been implied to promote ATL cell malignancy). Additionally, Hut102 and TL-Om1 displayed impaired expression of IKZF2 (deletion in HuT102 and altered translational variants in TL-Om1). LEN-induced growth inhibition to these two cell-lines seemed to be attributed to functional deprivation of all IKZF1/2/3. While CRBN-knockdown (KD) in HuT102 imposed LEN-resistance, IKZF2-KD in LEN-resistant ED40515 induced LEN sensitivity. DNA microarray analysis on LEN-treated HuT102 and OATL4 (LEN-resistant) displayed distinct LEN-responding transcriptional profiles; restoration of immune competency and oncogenic growth promotion respectively. Oral administration of LEN to HuT102-xenographted SCID mice demonstrated significant reduction of tumor mass. Finally, a novel form of IMiDs or cereblon modulator (CELMoD), iberdomide (IBE) exerted deeper and wider range of growth suppression to ATL cells including IKZF2 down regulation. Altogether, these findings strongly indicate the therapeutic advantages of IMiDs or CELMoD against ATL.
Project description:Adult T-cell lymphoma/leukemia (ATL) is an aggressive subtype of leukemia/lymphoma caused by human T-cell leukemia virus type-1 (HTLV-1) and existing chemotherapy for ATL remains with extremely poor prognosis. Therefore, more effective therapeutic options are urgent needs for this disease. Since recent two clinical studies proved promising curability of Lenalidomide (LEN, a second-generation immunomodulatory drug [IMiDs]) for ATL patients, we investigated the direct growth-inhibitory machineries of LEN on ATL cells. Among 13 ATL-related cell lines, Hut102 and TL-Om1 exhibited best response to LEN treatment and LEN-induced functional modulation of E3-ubiquitin ligase cereblon (CRBN) induced degradation of hematopoietic-specific ikaros-family transcription factors IKZF1 and IKZF3 followed by suppression of their down-stream effectors IRF4 and c-Myc (both have been implied to promote ATL cell malignancy). Additionally, Hut102 and TL-Om1 displayed impaired expression of IKZF2 (deletion in HuT102 and altered translational variants in TL-Om1). LEN-induced growth inhibition to these two cell-lines seemed to be attributed to functional deprivation of all IKZF1/2/3. While CRBN-knockdown (KD) in HuT102 imposed LEN-resistance, IKZF2-KD in LEN-resistant ED40515 induced LEN sensitivity. DNA microarray analysis on LEN-treated HuT102 and OATL4 (LEN-resistant) displayed distinct LEN-responding transcriptional profiles; restoration of immune competency and oncogenic growth promotion respectively. Oral administration of LEN to HuT102-xenographted SCID mice demonstrated significant reduction of tumor mass. Finally, a novel form of IMiDs or cereblon modulator (CELMoD), iberdomide (IBE) exerted deeper and wider range of growth suppression to ATL cells including IKZF2 down regulation. Altogether, these findings strongly indicate the therapeutic advantages of IMiDs or CELMoD against ATL.
Project description:To evaluate the impact of DNA demethylating agents on our mouse MDS model, we chose 5-aza-2’-deoxycytidine, decitabine (DAC), one of the DNA demethylating agents, which is incorporated into DNA but not RNA and has 10-fold more potency in DNA demethylation than 5-azacitidine. We transplanted Tet2KD/KDEzh2Δ/Δ MDS cells into lethally irradiated secondary recipients and treated them with DAC (low dose DAC at 0.25mg/kg, 3 times a week, intraperitoneal injection), then purified LSK HSPCs and evaluated the expression profiles.
Project description:Azacitidine (AZA) is a hypomethylating drug used to treat disorders associated with myelodysplasia and related neoplasms. Approximately 50% of patients do not respond to AZA and have very poor outcomes. It is of great interest to identify predictive biomarkers for AZA responsiveness. Therefore, we searched for specific genes whose expression level was associated with response status.Using microarrays, we analyzed gene expression patterns in bone marrow CD34+ cells from 32 patients with myelodysplastic syndromes, chronic myelomonocytic leukemia, and acute myeloid leukemia with myelodysplasia-related changes before AZA therapy. Total RNA was isolated from bone marrow CD34+ cells obtained from myelodysplasia and related neoplasms patients who underwent treatment with 5-azacytidine (AZA, Vidaza). Using Illumina Human HT-12 v. 4 microarrays, we assayed gene expression profiles in patient CD34+ cells before AZA treatment in order to collect basic data for search for markers of the prediction of therapy response.
Project description:Azacitidine (AZA) is a hypomethylating drug used to treat disorders associated with myelodysplasia and related neoplasms. Approximately 50% of patients do not respond to AZA and have very poor outcomes. It is of great interest to identify predictive biomarkers for AZA responsiveness. Therefore, we searched for specific genes whose expression level was associated with response status.Using microarrays, we analyzed gene expression patterns in bone marrow CD34+ cells from 32 patients with myelodysplastic syndromes, chronic myelomonocytic leukemia, and acute myeloid leukemia with myelodysplasia-related changes before AZA therapy.
Project description:The nucleotide analogue azacitidine (AZA) interferes with RNA and DNA metabolism and is currently the best treatment option for a subset of patients with high-risk myelodysplastic syndromes. However, only half of treated patients respond and almost all patients that initially respond eventually relapse. Thus, response-predicting biomarkers and new treatment options are urgently needed to improve the clinical management of these patients. Here, we performed a loss-of-function shRNA screen in combination with AZA treatment in a MDS-derived AML cell line to identify chromatin regulators affecting drug response. We identified the histone acetyl transferase and transcriptional co-activator CBP as a major regulator of AZA sensitivity. Compounds inhibiting the enzymatic activity of CBP synergistically reduced viability of MDS-derived AML cell lines when combined with AZA. Surprisingly, this affect was specific for the RNA-dependent functions of AZA and not observed with the related compound decitabine that is limited to DNA incorporation. The identification of immediate target genes suggested that the effect of CBP inhibition is mediated by downregulation of genes encoding the translational machinery, which could be confirmed in proteomic analysis of nascent proteins. Furthermore, proteins most affected by CBP inhibition include key drivers of cycle progression. Taken together, our results identify a novel synergistic interaction between CBP inhibitors and specifically AZA that warrants further evaluation for the combinatorial treatment of high-risk MDS patients. Beyond the scope of MDS and AZA, we provide novel insight in the function of clinically promising CBP inhibitors that is related to unexpected interference with the translational machinery.
Project description:H3K27ac HiChIP analysis was performed in an adult T-cell leukemia/lymphoma cell line (TL-Om1) to analyze active chromatin-chromatin interactions in TL-Om1 cells.
Project description:ChIP-seq analysis was performed in an adult T-cell leukemia/lymphoma cell line (TL-Om1) to analyze DNA bindings of TP73 in TL-Om1 cells.