2区 · 医学
Article
作者: Chrbolkova, Tereza ; Singh, Ram Kumar ; Sircar, Anuvrat ; Singh, Satishkumar ; Khashab, Tamer ; Hart, Amber ; Jain, Neeraj ; Muhowski, Elizabeth ; Alinari, Lapo ; Chowdhury, Sayan Mullick ; Samaniego, Felipe ; Woyach, Jennifer ; Zhu, Jiangjiang ; Shirazi, Fazal ; Sehgal, Lalit ; Havranek, Ondrej ; Laliotis, Georgios ; Baiocchi, Robert ; Tsichlis, Philip ; Kupcova, Kristyna
Abstract:Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma; 40% of patients relapse after a complete response or are refractory to therapy. To survive, the activated B-cell (ABC) subtype of DLBCL relies upon B-cell receptor signaling, which can be modulated by the activity of Bruton tyrosine kinase (BTK). Targeting BTK with ibrutinib, an inhibitor, provides a therapeutic approach for this subtype of DLBCL. However, non-Hodgkin lymphoma is often resistant to ibrutinib or acquires resistance soon after exposure. We explored how this resistance develops. We generated 3 isogenic ibrutinib-resistant DLBCL cell lines and investigated the deregulated pathways known to be associated with tumorigenic properties. Reduced levels of BTK and enhanced phosphatidylinositol 3-kinase (PI3K)/AKT signaling were hallmarks of these ibrutinib-resistant cells. Upregulation of PI3K-β expression was demonstrated to drive resistance in ibrutinib-resistant cells, and resistance was reversed by the blocking activity of PI3K-β/δ. Treatment with the selective PI3K-β/δ dual inhibitor KA2237 reduced both tumorigenic properties and survival-based PI3K/AKT/mTOR signaling of these ibrutinib-resistant cells. In addition, combining KA2237 with currently available chemotherapeutic agents synergistically inhibited metabolic growth. This study elucidates the compensatory upregulated PI3K/AKT axis that emerges in ibrutinib-resistant cells.