Mayo Clinic Laboratory and Pathology Research Roundup: March 20

The Research Roundup provides an overview of the past week’s research from Mayo Medical Laboratories consultants, including featured abstracts and complete list of published studies and reviews.


Featured Abstract

AKT-Phosphorylated FOXO1 Suppresses ERK Activation and Chemoresistance by Disrupting IQGAP1-MAPK Interaction

Nuclear FOXO proteins act as tumor suppressors by transcriptionally activating genes involved in apoptosis and cell cycle arrest, and these anticancer functions are inhibited by AKT-induced phosphorylation and cytoplasmic sequestration of FOXOs. Mayo Clinic researchers found that, after AKT-mediated phosphorylation at serine 319, FOXO1 binds to IQGAP1, a hub for activation of the MAPK pathway, and impedes IQGAP1-dependent phosphorylation of ERK1/2 (pERK1/2). Conversely, decreased FOXO1 expression increases pERK1/2 in cancer cell lines and correlates with increased pERK1/2 levels in patient specimens and disease progression. Treatment of cancer cells with PI3K inhibitors or taxane causes FOXO1 localization in the nucleus, increased expression of pERK1/2, and drug resistance. These effects are reversed by administering a small FOXO1-derived phospho-mimicking peptide inhibitor in vitro and in mice. These results show a tumor suppressor role of AKT-phosphorylated FOXO1 in the cytoplasm and suggest that this function of FOXO1 can be harnessed to overcome chemoresistance in cancer. The study was published in EMBO Journal.


Published to PubMed This Week

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Kelley Schreiber

Kelley Schreiber is a Marketing Channel Manager at Mayo Medical Laboratories. She is the principle editor and writer of Insights and leads social media and direct marketing strategy. Kelley has worked at Mayo Clinic since 2013. Outside of work, you can find Kelley running, traveling, playing with her new kitten, and exploring new foods.