A549 clone sensitivity to pemetrexed (200 nM) before and after IDO induction.

Proliferation of each of 5 individual A549 cell clonal populations before (Panel A) and after (Panel B) IDO induction with IFNγ. A549 clonal populations were cultured with or without IFNγ (25 ng/ml) for 48 h, then with pemetrexed (200 nM), and enumerated 72 h later. White bars: A549 clones transfected with scrambled, non-targeting control shRNA. Gray bars: A549 cells transfected with anti-IDO shRNA. Each bar represents the mean of 3 values (n = 3) ± SD. Results are normalized to control cells not treated with pemetrexed, without (panel A) or with (panel B) IFNγ treatment. Panel C: Induction of IDO in A549 clonal cell induces resistance to pemetrexed (200 nM). Results were obtained from 3 or 2 independent clonal cell populations with scrambled, non-targeting control shRNA or anti-IDO shRNA, respectively. Each bar represents a mean of 9 (white bars) or 6 (black bars) values ± SEM. *Significant difference, Student's t-test, p<0.05.

5株独立的A549细胞克隆群体在经干扰素γ（IFNγ）诱导吲哚胺2,3-双加氧酶（IDO）前后的增殖情况：图A为诱导前，图B为诱导后。A549克隆群体先在含或不含25 ng/ml干扰素γ（IFNγ）的培养基中培养48小时，随后加入200 nM培美曲塞，72小时后对细胞进行计数。白色柱形代表转染了随机非靶向对照短发夹RNA（shRNA）的A549克隆；灰色柱形代表转染了靶向IDO的短发夹RNA（shRNA）的A549细胞。每根柱形代表3次重复实验的平均值（n = 3）±标准差（standard deviation, SD）。实验结果以未接受培美曲塞处理的对照组细胞为基准进行归一化，其中图A对应未经过IFNγ处理的对照组，图B对应经过IFNγ处理的对照组。图C：A549克隆细胞中IDO的诱导表达可使其对200 nM培美曲塞产生耐药性。该结果分别来自3株转染了非靶向对照shRNA的独立克隆群体，以及2株转染了靶向IDO shRNA的独立克隆群体。每根白色柱形代表9次重复的平均值±标准误（standard error of the mean, SEM），黑色柱形则代表6次重复的平均值±标准误（standard error of the mean, SEM）。* 表示存在显著性差异，采用Student's t检验（Student's t-test），p<0.05。