GSE136414
Prolyl Hydroxylase Substrate Adenylosuccinate Lyase Is An Oncogenic Driver In Triple Negative Breast Cancer
Protein hydroxylation extensively regulates cellular signaling by affecting protein stability, activity, and interactome, therefore contributing to the pathogenesis of various diseases including cancers. However, because of the transient nature of the hydroxylase-substrate interaction, identifying new prolyl hydroxylation substrates remains a daunting challenge. Here, by developing a novel enzyme-substrate trapping strategy coupled with TAP-TAG or orthogonal GST- purification followed by mass spectrometry, we identify Adenylosuccinate lyase (ADSL) as a bona fide EglN2 prolyl hydroxylase substrate in triple negative breast cancer (TNBC). ADSL expression is significantly higher in TNBC than other breast cancer subtypes or normal breast tissues. Functionally, ADSL knockout greatly impairs TNBC 2-D and 3-D cell proliferation and invasiveness in vitro, as well as TNBC tumorigenesis and lung colonization in xenograft models. Mechanistically, an integrated transcriptomics and metabolomics analysis revealed that ADSL promotes the activation of the oncogenic cMYC pathway by regulating cMYC protein level via a mechanism requiring ADSL hydroxylation on proline 24. Specifically, hydroxylation-proficient ADSL, by affecting adenosine levels, represses the expression of the long non-coding RNA MIR22HG, thus upregulating the oncogene cMYC protein level and its target gene expression. Our findings identify the critical role of ADSL hydroxylation in controlling cMYC and TNBC tumorigenesis. Overall design: Transcriptional profiling of MDA-MB-231 cells treated with sgRNA targeting ADSL or control sgRNA