Matches in SemOpenAlex for { <https://semopenalex.org/work/W2791234932> ?p ?o ?g. }
- W2791234932 endingPage "02" @default.
- W2791234932 startingPage "GS2" @default.
- W2791234932 abstract "Abstract Inactivating germline mutations in the NF1 gene (encoding neurofibromin) cause neurofibromatosis type 1. In addition to peripheral nervous system tumors, NF1 patients are at higher risk for other cancers, including breast cancer. Tumor exome-sequencing studies demonstrate that approximately 20% of all human cancers have somatic NF1 mutations. NF1 has been best known for its ability to inactivate Ras as a GAP (GTPase Activating Protein). However, this function is served by a small GAP domain in a very large protein. Recurrent missense mutations inactivating the GAP activity are infrequent. In contrast, it is common to detect frameshift (FS) and nonsense (NS) NF1 mutations, which can create an NF1-null state deleting not only GAP, but also, potentially, undefined NF1 functions whose loss could also drive tumorigenesis. As we reported at SABCS previously, in 600+ patients treated by tamoxifen adjuvant monotherapy, we found that FS/NS NF1 mutations independently correlate with relapse risk (HR=2.6, p=0.03). To explore this finding, we silenced NF1 in preclinical models of ER+ breast cancer, which markedly enhanced ER transcriptional activities, causing estradiol (E2) hypersensitivity and converted tamoxifen into an agonist (in vitro and in vivo). Most important, these activities depend on ER, but not on NF1's GAP activity. These findings readily explain the poor patient outcomes associated with NS/FS NF1 mutations, and reveal a previously unrecognized function for NF1 in ER regulation. In the presence of an agonist, liganded ER repels co-repressors and recruits co-activators, while the reverse is true with an antagonist such as tamoxifen. Many co-regulators contain leucine/isoleucine rich motifs, which bind directly to the ligand-binding domain (LBD) in ER. NF1 has several of these motifs that are much more highly conserved in species with a functional ER pathway, and some of these are mutated in cancers (e.g., in our patient cohort). Furthermore, we found that NF1 canbind directly to ER, and that this binding is mediated between the ER LBD and the NF1 leucine-rich regions. Like a classic co-repressor, wildtype NF1 (but not mutants lacking GAP activity or the Leu-rich motif) binds to ER, and is recruited by ER to the ERE in the presence of tamoxifen, but not E2. Further preclinical treatment studies indicate that while NF1-deficient ER+ breast cancer should not be treated by tamoxifen or AIs, fulvestrant remains effective. Furthermore, when fulvestrant is combined with dabrafinib and trametinib to inhibit Ras effectors Raf and MEK, apoptosis is induced in vitro, and tumor regression is observed in vivo. In conclusion, we have demonstrated that NF1 is a dual negative regulator at the intersection of two potent oncogenic signaling pathways, Ras and ER, and that NF1-deficient ER+ breast cancer patients may be more effectively treated by co-targeting the Ras and ER signaling. These patients, up to 10% of those with advanced ER+ breast cancer, can be readily identified for treatment by ctDNA analysis. A clinical trial is under development. Citation Format: Chang EC, Zheng Z, Philip L, Burcu C, Lei J, Singh P, Anurag M, Chan D, Li JD, Du XP, Shafaee MN, Banks K, Sacker S, Song W, Nguyen T, Cao J, Chen X, Haricharan S, Kavuri M, Kim B-J, Zhang B, Gutmann DH, Lanman RB, Foulds C, Ellis M. Direct regulation of estrogen receptor-α (ER) transcriptional activity by NF1 [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr GS2-02." @default.
- W2791234932 created "2018-03-29" @default.
- W2791234932 creator A5005845489 @default.
- W2791234932 creator A5007718798 @default.
- W2791234932 creator A5016986363 @default.
- W2791234932 creator A5018447438 @default.
- W2791234932 creator A5019370942 @default.
- W2791234932 creator A5020997944 @default.
- W2791234932 creator A5024724100 @default.
- W2791234932 creator A5025322351 @default.
- W2791234932 creator A5029976443 @default.
- W2791234932 creator A5036030974 @default.
- W2791234932 creator A5044377323 @default.
- W2791234932 creator A5047173735 @default.
- W2791234932 creator A5049853194 @default.
- W2791234932 creator A5053815567 @default.
- W2791234932 creator A5054365404 @default.
- W2791234932 creator A5055111913 @default.
- W2791234932 creator A5057135409 @default.
- W2791234932 creator A5057751487 @default.
- W2791234932 creator A5067037220 @default.
- W2791234932 creator A5067835739 @default.
- W2791234932 creator A5072847671 @default.
- W2791234932 creator A5072959451 @default.
- W2791234932 creator A5074263344 @default.
- W2791234932 creator A5078489394 @default.
- W2791234932 creator A5091224239 @default.
- W2791234932 date "2018-02-15" @default.
- W2791234932 modified "2023-09-27" @default.
- W2791234932 title "Abstract GS2-02: Direct regulation of estrogen receptor-α (ER) transcriptional activity by NF1" @default.
- W2791234932 doi "https://doi.org/10.1158/1538-7445.sabcs17-gs2-02" @default.
- W2791234932 hasPublicationYear "2018" @default.
- W2791234932 type Work @default.
- W2791234932 sameAs 2791234932 @default.
- W2791234932 citedByCount "1" @default.
- W2791234932 countsByYear W27912349322018 @default.
- W2791234932 crossrefType "journal-article" @default.
- W2791234932 hasAuthorship W2791234932A5005845489 @default.
- W2791234932 hasAuthorship W2791234932A5007718798 @default.
- W2791234932 hasAuthorship W2791234932A5016986363 @default.
- W2791234932 hasAuthorship W2791234932A5018447438 @default.
- W2791234932 hasAuthorship W2791234932A5019370942 @default.
- W2791234932 hasAuthorship W2791234932A5020997944 @default.
- W2791234932 hasAuthorship W2791234932A5024724100 @default.
- W2791234932 hasAuthorship W2791234932A5025322351 @default.
- W2791234932 hasAuthorship W2791234932A5029976443 @default.
- W2791234932 hasAuthorship W2791234932A5036030974 @default.
- W2791234932 hasAuthorship W2791234932A5044377323 @default.
- W2791234932 hasAuthorship W2791234932A5047173735 @default.
- W2791234932 hasAuthorship W2791234932A5049853194 @default.
- W2791234932 hasAuthorship W2791234932A5053815567 @default.
- W2791234932 hasAuthorship W2791234932A5054365404 @default.
- W2791234932 hasAuthorship W2791234932A5055111913 @default.
- W2791234932 hasAuthorship W2791234932A5057135409 @default.
- W2791234932 hasAuthorship W2791234932A5057751487 @default.
- W2791234932 hasAuthorship W2791234932A5067037220 @default.
- W2791234932 hasAuthorship W2791234932A5067835739 @default.
- W2791234932 hasAuthorship W2791234932A5072847671 @default.
- W2791234932 hasAuthorship W2791234932A5072959451 @default.
- W2791234932 hasAuthorship W2791234932A5074263344 @default.
- W2791234932 hasAuthorship W2791234932A5078489394 @default.
- W2791234932 hasAuthorship W2791234932A5091224239 @default.
- W2791234932 hasConcept C104317684 @default.
- W2791234932 hasConcept C121608353 @default.
- W2791234932 hasConcept C126322002 @default.
- W2791234932 hasConcept C16671776 @default.
- W2791234932 hasConcept C170932241 @default.
- W2791234932 hasConcept C2777176818 @default.
- W2791234932 hasConcept C2778984943 @default.
- W2791234932 hasConcept C29906990 @default.
- W2791234932 hasConcept C501734568 @default.
- W2791234932 hasConcept C502942594 @default.
- W2791234932 hasConcept C530470458 @default.
- W2791234932 hasConcept C54355233 @default.
- W2791234932 hasConcept C71924100 @default.
- W2791234932 hasConcept C75563809 @default.
- W2791234932 hasConcept C86803240 @default.
- W2791234932 hasConceptScore W2791234932C104317684 @default.
- W2791234932 hasConceptScore W2791234932C121608353 @default.
- W2791234932 hasConceptScore W2791234932C126322002 @default.
- W2791234932 hasConceptScore W2791234932C16671776 @default.
- W2791234932 hasConceptScore W2791234932C170932241 @default.
- W2791234932 hasConceptScore W2791234932C2777176818 @default.
- W2791234932 hasConceptScore W2791234932C2778984943 @default.
- W2791234932 hasConceptScore W2791234932C29906990 @default.
- W2791234932 hasConceptScore W2791234932C501734568 @default.
- W2791234932 hasConceptScore W2791234932C502942594 @default.
- W2791234932 hasConceptScore W2791234932C530470458 @default.
- W2791234932 hasConceptScore W2791234932C54355233 @default.
- W2791234932 hasConceptScore W2791234932C71924100 @default.
- W2791234932 hasConceptScore W2791234932C75563809 @default.
- W2791234932 hasConceptScore W2791234932C86803240 @default.
- W2791234932 hasIssue "4_Supplement" @default.
- W2791234932 hasLocation W27912349321 @default.
- W2791234932 hasOpenAccess W2791234932 @default.
- W2791234932 hasPrimaryLocation W27912349321 @default.
- W2791234932 hasRelatedWork W1912271449 @default.
- W2791234932 hasRelatedWork W2044292902 @default.