Project description:Acute Myeloid Leukemia (AML) is the most common and aggressive form of acute leukemia, with a 5-year survival rate of just 24%. Over a third of all AML patients harbor activating mutations in kinases, such as the receptor tyrosine kinases FLT3 and KIT. FLT3 and KIT mutations are associated with poor clinical outcomes and lower remission rates in response to standard-of-care chemotherapy. We have recently identified that the core kinase of the non-homologous end joining DNA repair pathway, DNA-PK, is activated downstream of FLT3; and targeting DNA-PK sensitized FLT3-mutant AML cells to standard-of-care therapies. Herein, we investigated DNA-PK as a possible therapeutic vulnerability in KIT mutant AML, using isogenic FDC-P1 myeloid progenitor cell lines transduced with an empty vector or oncogenic mutant KIT (V560G, D816V). Targeted quantitative phosphoproteomic profiling identified phosphorylation of DNA-PK at threonine 2599 in KIT mutant cells, indicative of DNA-PK activation. Accordingly, proliferation assays revealed that KIT mutant FDC-P1 cells were more sensitive to the DNA-PK inhibitors M3814 or NU7441, compared to empty vector controls. DNA-PK inhibition combined with inhibition of KIT signaling via using the kinase inhibitors dasatinib or ibrutinib, or the protein phosphatase 2A activators FTY720 or AAL(S), led to synergistic cell death. Discovery phosphoproteomic analysis of KIT-D816V cells revealed that dasatinib single-agent treatment inhibited ERK1 activity, and M3814 single-agent treatment inhibited Akt/mTOR activity. The combination of dasatinib and M3814 treatment inhibited both ERK/MAPK and Akt/mTOR activity, and induced synergistic inhibition of phosphorylation of transcription regulators including MYC and MYB. This study provides insight into the oncogenic pathways regulated by DNA-PK beyond its canonical role in DNA repair, and demonstrates that DNA-PK is a promising novel therapeutic target for KIT mutant cancers.
Project description:Gene expression from MCF7 breast cancer cells at different times of TNFa incubation:pcs2 and 14-3-3 transduced cells Keywords: Expression Profiling by array
Project description:Transcriptome profiling of human umbilical vein endothelial cells (HUVECs) transduced with lentiviruses encoding FLAG-CAS9 nuclease and control- (gCTL) or cMYC-targeting (gMYC) gRNAS to identify cMYC regulated genes.
Project description:REtr causes genomic instability in U937 cells. Activated forms of c-KIT, like c-KIT(N822K), rescues the Retr induced genomic instability by increasing the rate of DNA repair by homologous recombination Human U937 cells were transduced with retroviral vectors encoding REtr or c-KIT(N822K), expanded in culture and FACS selected prior to molecular analysis
Project description:<p>The genetic basis of hypodiploid acute lymphoblastic leukemia (ALL), a subtype of ALL characterized by aneuploidy and poor outcome, is unknown. Genomic profiling of 124 hypodiploid ALL cases, including whole-genome and exome sequencing of 40 cases, identified two subtypes that differ in the severity of aneuploidy, transcriptional profiles and submicroscopic genetic alterations. Near-haploid ALL with 24-31 chromosomes harbor alterations targeting receptor tyrosine kinase signaling and Ras signaling (71%) and the lymphoid transcription factor gene IKZF3 (encoding AIOLOS; 13%). In contrast, low-hypodiploid ALL with 32-39 chromosomes are characterized by alterations in TP53 (91.2%) that are commonly present in nontumor cells, IKZF2 (encoding HELIOS; 53%) and RB1 (41%). Both near-haploid and low-hypodiploid leukemic cells show activation of Ras-signaling and phosphoinositide 3-kinase (PI3K)-signaling pathways and are sensitive to PI3K inhibitors, indicating that these drugs should be explored as a new therapeutic strategy for this aggressive form of leukemia.</p>
Project description:REtr causes genomic instability in human CD34+ cells. Activated forms of c-KIT, like c-KIT(N822K), rescue the REtr-induced genomic instability by increasing the rate of DNA repair by homologous recombination. Human CD34+ hematopoietic progenitor cells were transduced with retroviral vectors encoding c-KIT(N822K) or mock control vectors, expanded in culture and FACS selected prior to molecular analysis.
Project description:Human CD8+ T cells from three donors were transduced with lentivirus encoding for BATF3-2A-GFP or GFP and expanded for 10 days. Total RNA was isolated from each sample and submitted for RNA-seq. We then performed gene expression profiling analysis.