RNA interference screening identifies the Insulin/IGF-1 receptor pathway as a mechanism of escape from hormone dependence in breast cancer
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Miller Todd
PROVIDER: S-ECPF-GEOD-28580 | biostudies-other |
REPOSITORIES: biostudies-other
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Project description:A significant fraction of breast cancers exhibit de novo or acquired resistance to estrogen deprivation. A kinome-wide siRNA screen identified a role for Insulin Receptor (InsR) in the hormone-independent growth of ER+ breast cancer cells We used gene expression microarrays to identify genes and pathways that are altered by insulin stimulation of ER+ MCF-7 human breast cancer cells. MCF-7 cells were treated with serum-free medium +/- insulin for 4 or 24 hrs prior to RNA harvest for analysis.
2012-04-10 | E-GEOD-28580 | biostudies-arrayexpress
Project description:A significant fraction of breast cancers exhibit de novo or acquired resistance to estrogen deprivation. A kinome-wide siRNA screen identified a role for Insulin Receptor (InsR) in the hormone-independent growth of ER+ breast cancer cells We used gene expression microarrays to identify genes and pathways that are altered by insulin stimulation of ER+ MCF-7 human breast cancer cells.
2012-04-11 | GSE28580 | GEO
Project description:Estrogen receptor ? (ER)-positive breast cancers adapt to hormone deprivation and become resistant to antiestrogens. In this study, we sought to identify kinases essential for growth of ER(+) breast cancer cells resistant to long-term estrogen deprivation (LTED). A kinome-wide siRNA screen showed that the insulin receptor (InsR) is required for growth of MCF-7/LTED cells. Knockdown of InsR and/or insulin-like growth factor-I receptor (IGF-IR) inhibited growth of 3 of 4 LTED cell lines. Inhibition of InsR and IGF-IR with the dual tyrosine kinase inhibitor OSI-906 prevented the emergence of hormone-independent cells and tumors in vivo, inhibited parental and LTED cell growth and PI3K/AKT signaling, and suppressed growth of established MCF-7 xenografts in ovariectomized mice, whereas treatment with the neutralizing IGF-IR monoclonal antibody MAB391 was ineffective. Combined treatment with OSI-906 and the ER downregulator fulvestrant more effectively suppressed hormone-independent tumor growth than either drug alone. Finally, an insulin/IGF-I gene expression signature predicted recurrence-free survival in patients with ER(+) breast cancer treated with the antiestrogen tamoxifen. We conclude that therapeutic targeting of both InsR and IGF-IR should be more effective than targeting IGF-IR alone in abrogating resistance to endocrine therapy in breast cancer.
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2013-04-24 | E-GEOD-46307 | biostudies-arrayexpress
Project description:We used an in vivo short hairpin RNA (shRNA) screening approach to identify genes that are essential for MLL-AF9 acute myeloid leukemia (AML). We found that Integrin Beta 3 (Itgb3) is essential for murine leukemia cells in vivo, and for human leukemia cells in xenotransplantation studies.M-BM- In leukemia cells, Itgb3 knockdown impaired homing, downregulated LSC transcriptional programs, and induced differentiation via the intracellular kinase, Syk.M-BM- In contrast, loss of Itgb3 in normal HSPCs did not affect engraftment, reconstitution, or differentiation. M-BM- Finally, we confirmed that Itgb3 is dispensable for normal hematopoiesis and required for leukemogenesis using an Itgb3 knockout mouse model.M-BM- Our results establish the significance of the Itgb3 signaling pathway as a potential therapeutic target in AML. R940406 (R406, the active metabolite of fostamatinib) was supplied by Rigel Pharmaceuticals, Inc., South San Francisco, CA, and AstraZeneca Pharmaceuticals, Wilmington, DE, USA. R406 was resuspended in dimethyl sulfoxide (DMSO) (Sigma-Aldrich) and stored at M-bM-^HM-^R80M-BM-0C. . HL-60, U937 and KG-1 cell lines were purchased from the American Type Culture Collection. MOLM-14 cell lines were provided by Dr. Scott Amstrong (Dana-Farber Cancer Institute, Boston MA, USA.) All cell lines were maintained in RPMI 1640 (Cellgro) supplemented with 1% penicillin-streptomycin and 10% fetal bovine serum (FBS, Sigma-Aldrich) at 37 M-BM-0C with 5% CO2. MOLM-14, U937, HL-60 and KG-1 cells were grown in 4mM R406 for 24 hours
2013-04-24 | E-GEOD-46302 | biostudies-arrayexpress
Project description:Primary leukemia stem cells (LSCs) reside in an in vivo microenvironment that supports the growth and survival of malignant cells. We used an in vivo short hairpin RNA (shRNA) screening approach to identify novel genes that are essential for primary murine MLL-AF9 acute myeloid leukemia (AML). We found that Integrin Beta 3 (Itgb3) is selectively essential for murine leukemia cells in vivo, and for human leukemia cells in xenotransplantation studies. In leukemia cells, Itgb3 knockdown impaired homing, downregulated LSC transcriptional programs, and induced differentiation. In contrast, loss of Itgb3 in normal HSPCs did not affect engraftment, reconstitution, or differentiation in long term transplantation assays. We explored the signaling pathways downstream of Itgb3 using an additional in vivo shRNA screen and identified Syk as a critical mediator of Itgb3 activity in leukemia. Finally, we confirmed that Itgb3 is dispensable for normal hematopoiesis and required for leukemogenesis using the Itgb3 knockout mouse model. Our results establish the significance of the Itgb3 signaling pathway as a potential therapeutic target in AML, and demonstrate the utility of in vivo RNA interference screens.
2013-04-24 | GSE46307 | GEO
Project description:We used an in vivo short hairpin RNA (shRNA) screening approach to identify genes that are essential for MLL-AF9 acute myeloid leukemia (AML). We found that Integrin Beta 3 (Itgb3) is essential for murine leukemia cells in vivo, and for human leukemia cells in xenotransplantation studies. In leukemia cells, Itgb3 knockdown impaired homing, downregulated LSC transcriptional programs, and induced differentiation via the intracellular kinase, Syk. In contrast, loss of Itgb3 in normal HSPCs did not affect engraftment, reconstitution, or differentiation. Finally, we confirmed that Itgb3 is dispensable for normal hematopoiesis and required for leukemogenesis using an Itgb3 knockout mouse model. Our results establish the significance of the Itgb3 signaling pathway as a potential therapeutic target in AML. R940406 (R406, the active metabolite of fostamatinib) was supplied by Rigel Pharmaceuticals, Inc., South San Francisco, CA, and AstraZeneca Pharmaceuticals, Wilmington, DE, USA. R406 was resuspended in dimethyl sulfoxide (DMSO) (Sigma-Aldrich) and stored at −80°C. . HL-60, U937 and KG-1 cell lines were purchased from the American Type Culture Collection. MOLM-14 cell lines were provided by Dr. Scott Amstrong (Dana-Farber Cancer Institute, Boston MA, USA.) All cell lines were maintained in RPMI 1640 (Cellgro) supplemented with 1% penicillin-streptomycin and 10% fetal bovine serum (FBS, Sigma-Aldrich) at 37 °C with 5% CO2.
2013-04-24 | GSE46302 | GEO
Project description:UNLABELLED:Activation of fibroblast growth factor receptors (FGFR) is a common oncogenic event. Little is known about the determinants of sensitivity to FGFR inhibition and how these may vary between different oncogenic FGFRs. Using parallel RNA interference (RNAi) genetic screens, we show that the EGF receptor (EGFR) limits sensitivity to FGFR inhibition in FGFR3-mutant and -translocated cell lines, but not in other FGFR-driven cell lines. We also identify two distinct mechanisms through which EGFR limits sensitivity. In partially FGFR3-dependent lines, inhibition of FGFR3 results in transient downregulation of mitogen-activated protein kinase signaling that is rescued by rapid upregulation of EGFR signaling. In cell lines that are intrinsically resistant to FGFR inhibition, EGFR dominates signaling via repression of FGFR3, with EGFR inhibition rescued by delayed upregulation of FGFR3 expression. Importantly, combinations of FGFR and EGFR inhibitors overcome these resistance mechanisms in vitro and in vivo. Our results illustrate the power of parallel RNAi screens in identifying common resistance mechanisms to targeted therapies. SIGNIFICANCE:Our data identify a novel therapeutic approach to the treatment of FGFR3-mutant cancer, emphasizing the potential of combination approaches targeting both FGFR3 and EGFR. Our data extend the role of EGFR in mediating resistance to inhibitors targeting a mutant oncogene, showing that EGFR signaling can repress mutant FGFR3 to induce intrinsic resistance to FGFR targeting.
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Project description:BackgroundInsulin-like growth factor-II (IGF-II) promotes cell proliferation and survival and plays an important role in normal fetal development and placental function. IGF-II binds both the insulin-like growth factor receptor (IGF-1R) and insulin receptor isoform A (IR-A) with high affinity. Interestingly both IGF-II and the IR-A are often upregulated in cancer and IGF-II acts via both receptors to promote cancer proliferation. There is relatively little known about the mechanism of ligand induced activation of the insulin (IR) and IGF-1R. The recently solved IR structure reveals a folded over dimer with two potential ligand binding pockets arising from residues on each receptor half. Site-directed mutagenesis has mapped receptor residues important for ligand binding to two separate sites within the ligand binding pocket and we have recently shown that the IGFs have two separate binding surfaces which interact with the receptor sites 1 and 2.Methodology/principal findingsIn this study we describe a series of partial IGF-1R and IR agonists generated by mutating Glu12 of IGF-II. By comparing receptor binding affinities, abilities to induce negative cooperativity and potencies in receptor activation, we provide evidence that residue Glu12 bridges the two receptor halves leading to receptor activation.Conclusions/significanceThis study provides novel insight into the mechanism of receptor binding and activation by IGF-II, which may be important for the future development of inhibitors of its action for the treatment of cancer.
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