Gene expression alteration by different cell lines derived from lung SCC of IKKα mutant mice

In this study, we found that kinase-dead IKKα knockin (KAL) mice. develop spontaneous lung squamous cell carcinomas (SCCs) associated with IKKα downregulation and marked pulmonary inflammation.KKα downregulation dysregulates the expression of multiple oncogenes and tumor suppressors in K5+ lung epithelial cells. The mutant macrophages increase inflammatory responses and oxidative stress to promote DNA damage in IKKα-mutant K5+ lung epithelial cells, which further dysregulate the levels of multiple oncogenes, tumor suppressors, and stem cell genes, thereby promoting the IKKαlowK5+p63hi cell transition to tumor cells in L-IkkαKA/KA lungs. To further investigate the underlying mechanisms by which the lung SCC development, we generated two cell lines, named as S1 and S2 individually, which were derived from KAL lung SCC. The S1 cells express high level of Sca1 and exhibit tumorigenic phenotype, while the S2 cells express low level of Sca1 and exhibit less tumorigenic phenotype. The aim of this microarray assay is to identify differentially expressed genes between S1 and S2 cells, which may highlight the important genes or pathways involved in inflammation-associated lung SCC carcinogenesis. There were two cell lines were used to perform Gene chip assay with Affymetrix. The two cell lines, named as S1 and S2 individually, were derived from KAL lung SCC. The S1 cells express high level of Sca1 and exhibit tumorigenic phenotype, while the S2 cells express low level of Sca1 and exhibit less tumorigenic phenotype.

本研究发现，激酶失活性IKKα敲入（kinase-dead IKKα knockin, KAL）小鼠可自发形成肺鳞状细胞癌（lung squamous cell carcinomas, SCCs），该肿瘤伴随IKKα表达下调与显著肺部炎症。IKKα表达下调会异常调控K5阳性肺上皮细胞中多种癌基因与抑癌基因的表达。突变型巨噬细胞可增强炎症应答与氧化应激，进而促进IKKα突变型K5阳性肺上皮细胞发生DNA损伤，后者进一步异常调控多种癌基因、抑癌基因及干细胞基因的表达水平，最终推动L-IkkαKA/KA小鼠肺部中IKKα低表达/K5阳性/p63高表达细胞向肿瘤细胞的转化。
为进一步探究肺鳞状细胞癌发生的潜在分子机制，我们构建了两株分别命名为S1与S2的细胞系，二者均源自KAL小鼠肺鳞状细胞癌。其中S1细胞高表达Sca1并具有致瘤表型，而S2细胞低表达Sca1且致瘤能力较弱。本基因芯片实验旨在筛选S1与S2细胞间的差异表达基因，以期揭示炎症相关肺鳞状细胞癌癌变过程中的关键基因或信号通路。
本研究使用Affymetrix平台开展基因芯片实验，所用两株细胞系S1与S2均源自KAL小鼠肺鳞状细胞癌，其中S1细胞高表达Sca1并具有致瘤表型，S2细胞低表达Sca1且致瘤能力较弱。