Figure 2.

FAIM knockdown inhibits proliferation of lung adenocarcinoma cells and promotes lung differentiation events in xenograft models. (A-D) The lung adenocarcinoma cells A549(A), H1299(B), H292(C), SPC-A1(D) were cultured in RPMI 1640 with 10% FBS, cells were transfected with control siRNA (CON-si) or FAIM siRNAs (FAIM-si1, FAIM-si2). Twenty-four h later, cells were seeded in 24-well plates at 5000 cells per well in 0.5 ml complete culture medium. At indicated time, cells were fixed in 3.7% formaldehyde and stained with 0.1% crystal violet. Data represent the average of three independent experiments (mean ± SD). ***, P < 0.001 (upper panel). The lung adenocarcinoma cells were transfected with indicated siRNAs and 500 cells were seeded in 6-well plate. 10 days later, cells were fixed in 3.7% formaldehyde and stained with 0.1% crystal violet and the photographs were taken (middle panel). The knockdown efficiency of FAIM was detected by western blot using the indicated antibodies (bottom panel). (E) A549 control cells (A549-CON) and FAIM knockdown stable cell lines (A549-shFAIM) were subcutaneously injected into the flanks of nude mice. Four weeks later, tumors were dissected out and photomicrographs were taken. (F) The weights and volume of tumors in Figure 2E were measured. The p value was calculated by paired t-test, ***, P < 0.001. (G) Photomicrographs of hematoxylin-eosin (HE) staining for tumors induced by A549-CON cells and A549-shFAIM cells. Scale bars: 100 μm. (H and I) Immunohistochemical staining in tumors induced by A549-CON cells and A549-shFAIM cells for MKI67 (H) and NKX2-1 (I). Scale bars: 100 μm.