GBM response to Smo and PI3K inhibitors
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE49416 | GEO | 2013/09/01
SECONDARY ACCESSION(S): PRJNA213972
REPOSITORIES: GEO
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Project description:Combination therapy with Smo and PI3K inhibitors results in a synergistic effect in reducing tumor growth in PTEN-deficient Glioblastoma. To identify consequences of combination therapy with an Smo inhibitor and a PI3K inhibitor on a genome-wide scale, we performed Affymetrix microarrays with two different PTEN-deficient GBMs treated with single drugs or combination therapy. A small set of genes was significantly affected by combination therapy in hBT70 and/or hBT112, including several genes implicated in GBM prognosis, or identified as targets of Shh, PI3K or S6 pathways 29-33 . There are two different human GBM tumors (BT70 and BT112). Both are PTEN deficient. Samples were treated with DMSO (Control), LDE225 at 1 uM for 5 days, BKM 120 100 nM for 5 days, or LDE225 1 uM and BKM 120 100 nM for 5 days (Combo). Two biological replicates of each condition were analyzed.
2013-09-01 | E-GEOD-49416 | biostudies-arrayexpress
Project description:Activation of the PI3K pathway in estrogen receptor α (ER)-positive (+) breast cancer is associated with reduced ER expression and activity, luminal B subtype, and poor outcome. PTEN is a negative regulator of the PI3K pathway typically lost in ER-negative (-) breast cancer. To clarify the effect of PTEN down-regulation on the response of ER+/HER2- breast cancer to endocrine therapy, we established reduced PTEN cell models using inducible knockdown. We found that only moderate PTEN reduction is sufficient to enhance PI3K signaling, generate a gene signature associated with luminal B subtype, and cause endocrine resistance. Combining endocrine therapy with mTOR, AKT, or MEK inhibitors improves antitumor activity, but the efficacy varies by type of endocrine therapy and the specific inhibitor. Fulvestrant plus an AKT inhibitor is the most potent combination when PTEN is reduced, inducing apoptosis and tumor regression. This combination deserves further study in patients with PI3K pathway activation.
2014-06-30 | GSE53300 | GEO
Project description:Mutations in Hedgehog (Hh) pathway genes, leading to constitutive activation of Smoothened (Smo), occur in sporadic medulloblastoma, the most common brain cancer in children. Antagonists of Smo induce tumor regression in mouse models of medulloblastoma and hold great promise for targeted therapy for this tumor. However, acquired resistance has emerged as one of the major challenges of targeted cancer therapy. Here, we describe novel mechanisms of acquired resistance to Smo antagonists in medulloblastoma. NVP-LDE225, a potent and selective Smo antagonist, inhibits Hh signaling and induces tumor regressions in allograft models of medulloblastoma that are driven by mutations of Patched (Ptch), a tumor suppressor in the Hh pathway. However, after long-term treatment, evidence of acquired resistance was observed. Genome-wide profiling of resistant tumors revealed distinct mechanisms to evade the inhibitory effects of Smo antagonists. Chromosomal amplification of Gli2, a downstream effector of Hh signaling, reactivated Hh signaling and restored tumor growth. Analysis of pathway gene-expression signatures selectively deregulated in resistant tumors identified increased phosphoinosite-3-kinase (PI3K) signaling as another potential resistance mechanism. Probing the functional relevance of increased PI3K signaling, we showed that the combination of NVP-LDE225 with the dual PI3K/mTOR inhibitor NVP-BEZ235 markedly delayed the development of resistance. Our findings have important clinical implications for future treatment strategies in medulloblastoma. mRNA profiling: RNA was prepared from tumours from vehicle or NVP-LDE225 treated nude mice allografted with medulloblastoma tumors derived from Ptch+/-p53-/- transgenic mouse and hybridized on Affymetrix Mouse Genome 430 2.0 RNA expression array. The dosage terminology (BID & QD) reflects the dosing schedule, where BID = twice a day, QD = once a day. aCGH: DNA was prepared from tumors from vehicle or NVP-LDE225 treated nude mice allografted with medulloblastoma tumors derived from Ptch+/-p53-/- transgenic mouse and hybridized on Agilent mouse CGH 244K Array.
2010-09-29 | E-GEOD-19657 | biostudies-arrayexpress
Project description:Advanced basal cell carcinomas (BCCs) frequently acquire resistance to Smoothened (SMO) inhibitors through unknown mechanisms, providing a unique opportunity to study human tumor evolution. Here, we identify SMO mutations in 50% (22/44) of resistant BCCs compared with 5.6% (2/36) of untreated BCCs (p<0.0001), and show that these mutations maintain Hedgehog signaling in the presence of SMO inhibitors. Alterations include four ligand binding pocket (LBP) mutations that define sites of inhibitor binding and four variants that confer constitutive activity and inhibitor resistance, thus defining pivotal residues of SMO that ensure receptor autoinhibition. Finally, we show that both classes of SMO variants respond to the aPKC-ι/λ inhibitor PSI and GLI2 antagonist ATO that operate downstream of SMO
2015-03-16 | GSE58376 | GEO
Project description:Advanced basal cell carcinomas (BCCs) frequently acquire resistance to Smoothened (SMO) inhibitors through unknown mechanisms, providing a unique opportunity to study human tumor evolution. Here, we identify SMO mutations in 50% (22/44) of resistant BCCs compared with 5.6% (2/36) of untreated BCCs (p<0.0001), and show that these mutations maintain Hedgehog signaling in the presence of SMO inhibitors. Alterations include four ligand binding pocket (LBP) mutations that define sites of inhibitor binding and four variants that confer constitutive activity and inhibitor resistance, thus defining pivotal residues of SMO that ensure receptor autoinhibition. Finally, we show that both classes of SMO variants respond to the aPKC-ι/λ inhibitor PSI and GLI2 antagonist ATO that operate downstream of SMO
2015-03-16 | GSE58375 | GEO
Project description:Advanced basal cell carcinomas (BCCs) frequently acquire resistance to Smoothened (SMO) inhibitors through unknown mechanisms, providing a unique opportunity to study human tumor evolution. Here, we identify SMO mutations in 50% (22/44) of resistant BCCs compared with 5.6% (2/36) of untreated BCCs (p<0.0001), and show that these mutations maintain Hedgehog signaling in the presence of SMO inhibitors. Alterations include four ligand binding pocket (LBP) mutations that define sites of inhibitor binding and four variants that confer constitutive activity and inhibitor resistance, thus defining pivotal residues of SMO that ensure receptor autoinhibition. Finally, we show that both classes of SMO variants respond to the aPKC-ι/λ inhibitor PSI and GLI2 antagonist ATO that operate downstream of SMO.
2015-03-16 | GSE58374 | GEO
Project description:Purpose: PTEN loss-of-function occurs in ~50% of metastatic, castrate-resistant prostate cancer (mCRPC) patients, and associated with poor prognosis and responsiveness to standard-of-care therapies and immune checkpoint inhibitors. While PTEN loss-of-function hyperactivates PI3K signaling, combinatorial PI3K/AKT pathway and androgen deprivation therapy (ADT) has demonstrated limited anti-cancer efficacy in clinical trials. Here, we aimed to elucidate mechanism(s) of resistance to ADT/PI3K-AKT axis blockade, and to develop rational combinatorial strategies to effectively treat this molecular subset of mCRPC. Experimental design: Prostate-specific PTEN/p53-deficient genetically engineered mice (GEM) with established 150-200 mm3 tumors, as assessed by ultrasound, were treated with either ADT (degarelix), PI3K inhibitor (copanlisib), or anti-PD-1 antibody (aPD-1), as single agents or their combinations, and tumors were monitored by MRI and harvested for immune, transcriptomic and proteomic profiling, or ex vivo co-culture studies. Single-cell RNAseq on human mCRPC samples was performed using 10X Genomics platform. Results: Co-clinical trials in PTEN/p53-deficient GEM revealed that recruitment of PD-1-expressing tumor-associated macrophages (TAM) thwarts ADT/PI3Ki combination-induced tumor control. The addition of aPD-1 to ADT/PI3Ki combination led to TAM-dependent ~3-fold increase in anti-cancer responses. Mechanistically, decreased lactate production from PI3Ki-treated tumor cells suppressed histone lactylation within TAM, resulting in their anti-cancer phagocytic activation, which was augmented by ADT/aPD-1 treatment and abrogated by feedback activation of Wnt/β-catenin pathway. Single-cell RNA-sequencing analysis in mCRPC patient biopsy samples revealed a direct correlation between high glycolytic activity and TAM phagocytosis suppression. Conclusions: Immunometabolic strategies that reverse lactate and PD-1-mediated TAM immunosuppression, in combination with ADT, warrant further investigation in PTEN-deficient mCRPC patients.
2023-02-21 | GSE225074 | GEO
Project description:Mutations in Hedgehog (Hh) pathway genes, leading to constitutive activation of Smoothened (Smo), occur in sporadic medulloblastoma, the most common brain cancer in children. Antagonists of Smo induce tumor regression in mouse models of medulloblastoma and hold great promise for targeted therapy for this tumor. However, acquired resistance has emerged as one of the major challenges of targeted cancer therapy. Here, we describe novel mechanisms of acquired resistance to Smo antagonists in medulloblastoma. NVP-LDE225, a potent and selective Smo antagonist, inhibits Hh signaling and induces tumor regressions in allograft models of medulloblastoma that are driven by mutations of Patched (Ptch), a tumor suppressor in the Hh pathway. However, after long-term treatment, evidence of acquired resistance was observed. Genome-wide profiling of resistant tumors revealed distinct mechanisms to evade the inhibitory effects of Smo antagonists. Chromosomal amplification of Gli2, a downstream effector of Hh signaling, reactivated Hh signaling and restored tumor growth. Analysis of pathway gene-expression signatures selectively deregulated in resistant tumors identified increased phosphoinosite-3-kinase (PI3K) signaling as another potential resistance mechanism. Probing the functional relevance of increased PI3K signaling, we showed that the combination of NVP-LDE225 with the dual PI3K/mTOR inhibitor NVP-BEZ235 markedly delayed the development of resistance. Our findings have important clinical implications for future treatment strategies in medulloblastoma.
2010-09-29 | GSE19657 | GEO
Project description:Abstract BACKGROUND: The basal-like breast cancer (BLBC) subtype is characterized by positive staining for basal mammary epithelial cytokeratin markers, lack of hormone receptor and HER2 expression, and poor prognosis with currently no approved molecularly-targeted therapies. The oncogenic signaling pathways driving basal-like tumorigenesis are not fully elucidated. METHODS: One hundred sixteen unselected breast tumors were subjected to integrated analysis of phosphoinositide 3-kinase (PI3K) pathway related molecular aberrations by immunohistochemistry, mutation analysis, and gene expression profiling. Incidence and relationships between molecular biomarkers were characterized. Findings for select biomarkers were validated in an independent series. Synergistic cell killing in vitro and in vivo tumor therapy was investigated in breast cancer cell lines and mouse xenograft models, respectively. RESULTS: Sixty-four % of cases had an oncogenic alteration to PIK3CA, PTEN, or INPP4B; when including upstream kinases HER2 and EGFR, 75 % of cases had one or more aberration including 97 % of estrogen receptor (ER)-negative tumors. PTEN-loss was significantly associated to stathmin and EGFR overexpression, positivity for the BLBC markers cytokeratin 5/14, and the BLBC molecular subtype by gene expression profiling, informing a potential therapeutic combination targeting these pathways in BLBC. Combination treatment of BLBC cell lines with the EGFR-inhibitor gefitinib plus the PI3K pathway inhibitor LY294002 was synergistic, and correspondingly, in an in vivo BLBC xenograft mouse model, gefitinib plus PI3K-inhibitor PWT-458 was more effective than either monotherapy and caused tumor regression. CONCLUSIONS: Our study emphasizes the importance of PI3K/PTEN pathway activity in ER-negative and basal-like breast cancer and supports the future clinical evaluation of combining EGFR and PI3K pathway inhibitors for the treatment of BLBC. Gene expression profiles were generated for 95 breast tumors using Agilent Human 44K v5 microarrays following the manufacturer protocol. Stratagene Universal Human Reference RNA was used as the common control sample.
2016-08-21 | E-GEOD-74667 | biostudies-arrayexpress
Project description:The A375, human BRAFV600E mutant melanoma, cell line (wildtype), two PTEN-null, BRAFV600E cell lines (KO5 and KO11), and PI3K overexpression cells (WT and PI3K H1047R mutant) were treated with small molecule inhibitors (dabrafenib, BRAF inhibitor; trametinib, MEK inhibitor alone and in combination for 0, 1 and 7 days
2019-04-27 | GSE130396 | GEO