Browsing by Author "Eterovic, Agda Karina"

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    Role of RPL39 in Metaplastic Breast Cancer
    (Oxford, 2017) Dave, Bhuvanesh; Gonzalez, Daniel D.; Liu, Zhi-Bin; Li, Xiaoxian; Wong, Helen; Granados, Sergio; Ezzedine, Nadeer E.; Sieglaff, Douglas H.; Ensor, Joe E.; Miller, Kathy D.; Radovich, Milan; Eterovic, Agda Karina; Gross, Steven S.; Elemento, Olivier; Mills, Gordon B.; Gilcrease, Michael Z.; Chang, Jenny C.; Medicine, School of Medicine
    Background: Metaplastic breast cancer is one of the most therapeutically challenging forms of breast cancer because of its highly heterogeneous and chemoresistant nature. We have previously demonstrated that ribosomal protein L39 (RPL39) and its gain-of-function mutation A14V have oncogenic activity in triple-negative breast cancer and this activity may be mediated through inducible nitric oxide synthase (iNOS). The function of RPL39 and A14V in other breast cancer subtypes is currently unknown. The objective of this study was to determine the role and mechanism of action of RPL39 in metaplastic breast cancer. Methods: Both competitive allele-specific and droplet digital polymerase chain reaction were used to determine the RPL39 A14V mutation rate in metaplastic breast cancer patient samples. The impact of RPL39 and iNOS expression on patient overall survival was estimated using the Kaplan-Meier method. Co-immunoprecipitation and immunoblot analyses were used for mechanistic evaluation of RPL39. Results: The RPL39 A14V mutation rate was 97.5% (39/40 tumor samples). High RPL39 (hazard ratio = 0.71, 95% confidence interval = 0.55 to 0.91, P = .006) and iNOS expression (P = .003) were associated with reduced patient overall survival. iNOS inhibition with the pan-NOS inhibitor NG-methyl-L-arginine acetate decreased in vitro proliferation and migration, in vivo tumor growth in both BCM-4664 and BCM-3807 patient-derived xenograft models (P = .04 and P = .02, respectively), and in vitro and in vivo chemoresistance. Mechanistically, RPL39 mediated its cancer-promoting actions through iNOS signaling, which was driven by the RNA editing enzyme adenosine deaminase acting on RNA 1. Conclusion: NOS inhibitors and RNA editing modulators may offer novel treatment options for metaplastic breast cancer.
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    The mutational landscape and functional effects of noncoding ultraconserved elements in human cancers
    (American Association for the Advancement of Science, 2025) Bayraktar, Recep; Tang, Yitao; Dragomir, Mihnea P.; Ivan, Cristina; Peng, Xinxin; Fabris, Linda; Zhang, Jianhua; Carugo, Alessandro; Aneli, Serena; Liu, Jintan; Chen, Mei-Ju M.; Srinivasan, Sanjana; Sahnoune, Iman; Bayraktar, Emine; Akdemir, Kadir C.; Chen, Meng; Narayanan, Pranav; Huang, Wilson; Ott, Leonie Florence; Eterovic, Agda Karina; Villarreal, Oscar Eduardo; Mohammad, Mohammad Moustaf; Peoples, Michael D.; Walsh, Danielle M.; Hernandez, Jon Andrew; Morgan, Margaret B.; Shaw, Kenna R.; Davis, Jennifer S.; Menter, David; Tam, Constantine S.; Yeh, Paul; Dawson, Sarah-Jane; Rassenti, Laura Z.; Kipps, Thomas J.; Kunej, Tanja; Estrov, Zeev; Joosse, Simon A.; Pagani, Luca; Alix-Panabières, Catherine; Pantel, Klaus; Ferajoli, Alessandra; Futreal, Andrew; Wistuba, Ignacio I.; Radovich, Milan; Kopetz, Scott; Keating, Michael J.; Draetta, Giulio F.; Mattick, John S.; Liang, Han; Calin, George A.; Surgery, School of Medicine
    The mutational landscape of phylogenetically ultraconserved elements (UCEs), especially those in noncoding DNAs (ncUCEs), and their functional relevance in cancers remain poorly characterized. Here, we perform a systematic analysis of whole-genome and in-house targeted UCE sequencing datasets from more than 3000 patients with cancer of 13,736 UCEs and demonstrate that ncUCE somatic alterations are common. Using a multiplexed CRISPR knockout screen in colorectal cancer cells, we show that the loss of several altered ncUCEs significantly affects cell proliferation. In-depth functional studies in vitro and in vivo further reveal that specific ncUCEs can be enhancers of tumor suppressors (such as ARID1B) and silencers of oncogenic proteins (such as RPS13). Moreover, several miRNAs located in ncUCEs are recurrently mutated. Mutations in miR-142 locus can affect the Drosha-mediated processing of precursor miRNAs, resulting in the down-regulation of the mature transcript. These results provide systematic evidence that specific ncUCEs play diverse regulatory roles in cancer.