Similar Datasets
Project description:The heterogeneous therapy response observed in colorectal cancer is in part due to cancer stem cells (CSCs) that resist chemotherapeutic insults. The anti-apoptotic protein BCL-XL plays a critical role in protecting CSCs from cell death, where its inhibition with high doses of BH3-mimetics can induce apoptosis. To identify pathways that can regulate sensitivity to BCL-XL inhibition, we screened a compound library for synergy with low dose BCL-XL inhibitor A-1155463 and reveal that FGFR4 inhibition effectively sensitizes to A-1155463 both in vitro and in vivo. Mechanistically, we identify a rescue response that is activated upon BCL-XL inhibition and leads to rapid FGF2 secretion and subsequent FGFR4-mediated post-translational stabilization of MCL-1. FGFR4 inhibition prevents MCL-1 upregulation and thereby sensitizes CSCs to BCL-XL inhibition. Altogether, our findings suggest a cell transferable induction of a FGF2/FGFR4 rescue response in CRC that is induced upon BCL-XL inhibition and leads to MCL-1 upregulation.
2021-12-22 | GSE159504 | GEO
Project description:Bcl-xL is an anti-apoptotic protein that is frequently found to be overexpressed in non-small cell lung cancer leading to an inhibition of apoptosis and poor prognosis. Recently, the role of miRNAs in regulating apoptosis and cell survival during tumorigenesis has become evident, with cancer cells showing perturbed expression of various miRNAs. We utilized miRNA microarrays to determine if miRNA dysregulation in bcl-xL silenced lung adenocarcinoma cells could be involved in regulating apoptotic behavior, and identified dysregulated miRNAs with putative targets involved in signal transduction pathways regulating apoptosis, cell proliferation and cell progression. Short interfering RNA-based transfection of A549 was carried out inducing a reduction in bcl-xL expression levels. 24 hours post-transfection total RNA was isolated using TRIzol reagent and hybridized onto Affymetrix GeneChip miRNA Arrays. A global miRNA expression profile was then established, which compared total RNA, extracted from siRNA-transfected and non-transfected A549 cells. All experiments were carried out with three independent biological replicates.
2013-05-18 | E-GEOD-47059 | biostudies-arrayexpress
Project description:Genome-wide genetic screens have identified cellular dependencies in many cancers. Using Novartis’ DRIVE and the Broad Institute’s Achilles shRNA screening datasets, we mined for targetable dependencies in kidney lineage cancer cells. Our studies identified a dependency, preferentially in kidney cancer cells versus cells of other lineages, on the BCL2L1 gene, which encodes the Bcl-xL anti-apoptotic protein. Genetic and pharmacological inactivation of Bcl-xL, but not its paralog BCL2, led to fitness defects in renal cancer cells, and also sensitized them to chemotherapeutics. Expression levels of Bcl-xL, VHL status, and p53 mutation status were insufficient to predict Bcl-xL dependence. Instead, analyzing the transcriptional hallmarks of response to Bcl-xL blockade identified an elevated mesenchymal cell state signature in Bcl-xL dependent lines. Functional studies to address if these cell state differences drive Bcl-xL dependence showed that maintaining mesenchymal characteristics was necessary to confer sensitivity to Bcl-xL loss; and, conversely, that promoting mesenchymal transition was sufficient to increase sensitivity to Bcl-xL inhibition in resistant cells. This mesenchymal signature was also observed in almost a third of human renal tumors, and is associated with worse clinical outcomes. Detachment from an organized epithelium incites protective apoptotic responses in normal cells (e.g. anoikis); however, our findings suggest that, in mesenchymal kidney cancer cells Bcl-xL activity counteracts this protective mechanism and enables tumor cell survival. Altogether, our studies uncover an unexpected link between cellular cell state and dependence on anti-apoptotic proteins, and justify the use of Bcl-xL blockade to target a clinically aggressive subset of human kidney cancers.
2022-06-15 | GSE173618 | GEO
Project description:The anti-apoptotic function of Bcl-xL in the heart against reperfusion injury is diminished by K-Ras-Mst1-mediated phosphorylation of Ser14, which allows dissociation of Bcl-xL from Bax and promotes cardiomyocyte death. Here we show that Ser14 phosphorylation of Bcl-xL is also promoted by hemodynamic stress in the heart, through the H-Ras-ERK pathway. Our study suggests that phosphorylation of Bcl-xL at Ser14 in response to acute pressure overload plays an essential role in mediating compensatory hypertrophy by promoting calcium release, alleviating the negative constraint of Bcl-xL upon the IP3R-NFAT pathway.
2023-09-06 | PXD045118 | Pride
Project description:Bcl-xL is an anti-apoptotic protein that is frequently found to be overexpressed in non-small cell lung cancer leading to an inhibition of apoptosis and poor prognosis. Recently, the role of miRNAs in regulating apoptosis and cell survival during tumorigenesis has become evident, with cancer cells showing perturbed expression of various miRNAs. We utilized miRNA microarrays to determine if miRNA dysregulation in bcl-xL silenced lung adenocarcinoma cells could be involved in regulating apoptotic behavior, and identified dysregulated miRNAs with putative targets involved in signal transduction pathways regulating apoptosis, cell proliferation and cell progression.
2013-05-18 | GSE47059 | GEO
Project description:High-risk B-cell acute lymphoblastic leukemia (B-ALL) is an aggressive disease, often characterized by resistance to chemotherapy. A frequent feature of high-risk B-ALL is loss of function of the Ikaros tumor suppressor. In leukemia, Ikaros’ function is impaired by oncogenic Casein Kinase II (CK2), which is overexpressed in B-ALL. Phosphorylation by CK2 reduces Ikaros binding to the promoter of its target gene, particularly Bcl-xL. This results in a loss of Ikaros-mediated repression of Bcl-xL and in increased expression of Bcl-xL. Increased expression of Bcl-xL and/or CK2, as well as reduced Ikaros expression, are associated with resistance to doxorubicin treatment. Molecular and pharmacological inhibition of CK2 with a specific inhibitor CX-4945, enhances Ikaros-mediated repression of Bcl-xL and increases sensitivity to doxorubicin. Combination treatment with CX-4945 and doxorubicin show synergistic therapeutic effects in vitro and in preclinical models of high-risk B-ALL. Results reveal a novel signaling network that regulates chemoresistance in leukemia and lays the groundwork for clinical testing of CK2 inhibitors in combination with doxorubicin for the treatment of hematopoietic malignancies.
2020-11-27 | GSE141572 | GEO
Project description:Glioblastomas harbor a super-enhancer at the MCL1 locus, which translates to increased MCL1 levels as compared to normal brain tissue. While suppression of Mcl-1 alone did not yield in significant apoptosis induction, combined inhibition of Bcl-xL/Bcl-2 along with Mcl-1 led to strong cell killing and reduction of tumor growth in patient-derived xenograft models in vivo.
2020-05-22 | GSE150986 | GEO
Project description:Overexpression of BCL-xL and BCL-2 play key roles in tumorigenesis and cancer drug resistance. Advances in PROTAC technology facilitated recent development of the first BCL-xL/BCL-2 dual degrader, 753b, a VHL-based degrader with improved potency and reduced toxicity compared to previous small molecule inhibitors. Here, we determined crystal structures of VHL/753b/BCL-xL and VHL/753b/ BCL-2 ternary complexes. The two ternary complexes exhibit markedly different architectures that are accompanied by distinct networks of interactions at the VHL/PZ753b-linker/target interfaces. The importance of these interfacial contacts was validated via functional analysis and informed subsequent rational and structure-guided design focused on the 753b linker and BCL-2/BCL-xL warhead. This resulted in the design of a novel degrader, WH244, with enhanced potency to degrade BCL-xL/BCL-2 in cells. Using biophysical assays followed by in cell activities, we were able to explain the enhanced target degradation of BCL-2/BCL-xL in cells. Most PROTACs are empirically designed and lack structural studies, making it challenging to understand their modes of action and specificity. Our work presents a streamlined approach that combines rational design and structure-based insights backed with cell-based studies to develop effective PROTAC-based cancer therapeutics.
2024-03-12 | PXD049976 | Pride
Project description:To validate the specificity of DT2216, we used the stable isotope labeling with amino acids in cell culture (SILAC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics to analyze the changes in proteins in WI-38 normal human diploid fibroblasts after DT2216 and DT2216NC treatment. The results show that DT2216, but not DT2216NC, reduced the levels of BCL-XL, but none of other proteins were significantly affected by either agent, demonstrating that DT2216 is a specific BCL-XL PROTAC.
2019-10-08 | PXD010878 | Pride
Project description:Overexpression of BCL-xL and BCL-2 play key roles in tumorigenesis and cancer drug resistance. Advances in PROTAC technology facilitated recent development of the first BCL-xL/BCL-2 dual degrader, 753b, a VHL-based degrader with improved potency and reduced toxicity compared to previous small molecule inhibitors. Here, we determined crystal structures of VHL/753b/BCL-xL and VHL/753b/ BCL-2 ternary complexes. The two ternary complexes exhibit markedly different architectures that are accompanied by distinct networks of interactions at the VHL/PZ753b-linker/target interfaces. The importance of these interfacial contacts was validated via functional analysis and informed subsequent rational and structure-guided design focused on the 753b linker and BCL-2/BCL-xL warhead. This resulted in the design of a novel degrader, WH244, with enhanced potency to degrade BCL-xL/BCL-2 in cells. Using biophysical assays followed by in cell activities, we were able to explain the enhanced target degradation of BCL-2/BCL-xL in cells. Most PROTACs are empirically designed and lack structural studies, making it challenging to understand their modes of action and specificity. Our work presents a streamlined approach that combines rational design and structure-based insights backed with cell-based studies to develop effective PROTAC-based cancer therapeutics.
2024-02-21 | MSV000094144 | MassIVE