Browsing by Author "Whitsett, Jeffrey A."

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    A novel PI3K inhibitor iMDK suppresses non-small cell lung Cancer cooperatively with A MEK inhibitor
    (Elsevier, 2015-07-15) Ishida, Naomasa; Fukazawa, Takuya; Maeda, Yutaka; Yamatsuji, Tomoki; Takaoka, Munenori; Haisa, Minoru; Yokota, Etsuko; Shigemitsu, Kaori; Morita, Ichiro; Kato, Katsuya; Matsumoto, Kenichi; Shimo, Tsuyoshi; Okui, Tatsuo; Bao, Xiao-Hong; Hao, Huifang; Grant, Shawn N.; Takigawa, Nagio; Whitsett, Jeffrey A.; Naomoto, Yoshio; Department of Medicine, Division of Hematology and Oncology, IU School of Medicine
    The PI3K–AKT pathway is expected to be a therapeutic target for non-small cell lung cancer (NSCLC) treatment. We previously reported that a novel PI3K inhibitor iMDK suppressed NSCLC cells in vitro and in vivo without harming normal cells and mice. Unexpectedly, iMDK activated the MAPK pathway, including ERK, in the NSCLC cells. Since iMDK did not eradicate such NSCLC cells completely, it is possible that the activated MAPK pathway confers resistance to the NSCLC cells against cell death induced by iMDK. In the present study, we assessed whether suppressing of iMDK-mediated activation of the MAPK pathway would enhance anti-tumorigenic activity of iMDK. PD0325901, a MAPK inhibitor, suppressed the MAPK pathway induced by iMDK and cooperatively inhibited cell viability and colony formation of NSCLC cells by inducing apoptosis in vitro. HUVEC tube formation, representing angiogenic processes in vitro, was also cooperatively inhibited by the combinatorial treatment of iMDK and PD0325901. The combinatorial treatment of iMDK with PD0325901 cooperatively suppressed tumor growth and tumor-associated angiogenesis in a lung cancer xenograft model in vivo. Here, we demonstrate a novel treatment strategy using iMDK and PD0325901 to eradicate NSCLC.
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    TGFBI functions similar to periostin but is uniquely dispensable during cardiac injury
    (PLOS, 2017-07-27) Schwanekamp, Jennifer A.; Lorts, Angela; Sargent, Michelle A.; York, Allen J.; Grimes, Kelly M.; Fischesser, Demetria M.; Gokey, Jason J.; Whitsett, Jeffrey A.; Conway, Simon J.; Molkentin, Jeffery D.; Pediatrics, School of Medicine
    Extracellular matrix production and accumulation stabilize the heart under normal conditions as well as form a protective scar after myocardial infarction injury, although excessive extracellular matrix accumulation with long-standing heart disease is pathological. In the current study we investigate the role of the matricellular protein, transforming growth factor beta-induced (TGFBI), which is induced in various forms of heart disease. Additionally, we sought to understand whether TGFBI is functionally redundant to its closely related family member periostin, which is also induced in the diseased heart. Surgical models of myocardial infarction and cardiac pressure overload were used in mice with genetic loss of Postn and/or Tgfbi to examine the roles of these genes during the fibrotic response. Additionally, cardiac-specific TGFBI transgenic mice were generated and analyzed. We observed that deletion of Tgfbi did not alter cardiac disease after myocardial infarction in contrast to greater ventricular wall rupture in Postn gene-deleted mice. Moreover, Tgfbi and Postn double gene-deleted mice showed a similar post-myocardial infarction disease phenotype as Postn-deleted mice. Over-expression of TGFBI in the hearts of mice had a similar effect as previously shown in mice with periostin over-expression. Thus, TGFBI and periostin act similarly in the heart in affecting fibrosis and disease responsiveness, although TGFBI is not seemingly necessary in the heart after myocardial infarction injury and is fully compensated by the more prominently expressed effector periostin.