Fig. 7: Acalabrutinib suppresses the EGFR TKI-resistant H1975 cells in vivo.

A Experimental chart of in vivo studies. Photographs of NSCLC cells, H1975 (1 × 10⁶ cells/injection, subcutaneous) were injected into mice for establishing tumor xenograft model. When tumor size became palpable, mice were separated into four groups: Vehicle control, Osimertinib (20 mg/Kg, i.p injection, 5 times a week), Acalabrutinib (25 mg/kg, i.p. injection, 5 times a week), and combination of Osimertinib + Acalabrutinib. B–D Gross view, tumor weight and tumor size of H1975 tumors in the xenograft model. E Kaplan–Meier survival curve of the xenograft model. F Representative immunohistochemical staining images of differential expression of BTK, cleaved Caspase-3, Ki-67, and TUNEL in tumors extracted from the Osimertinib- and/or Acalabrutinib-treated NOD/SCID mice. *p < 0.05; **p < 0.01; ***p < 0.001. G Schematic illustration of current study. The in vitro studies demonstrated that Acalabrutinib suppressed SOX2 and STAT3/JAK2/Akt axis, leading to decreased stemness and EMT in A549 and PC-9 cells. The in vivo studies suggested that combination of Acalabrutinib and Osimertinib could effectively decrease tumorigenesis of H1975 cells.