mRNA expression levels of CCL4, IL6, and CXCL2 in multiwalled carbon nanotube induced lung tumors in rats

Some types of multiwalled carbon nanotube (MWCNT) are similar to asbestos in length and diameter. When these fibers are introduced into the respiratory tract, MWCNTs can induce pulmonary lesions including inflammation, fibrosis, and hyperplasia. By using an intrapulmonary spraying method, we demonstrate that MWCNT causes lung cancer in a 2-year experimental protocol (Suzui et al., 2016). In samples of the 5 histologically diagnosed archival lung cancer tissues and 4 control normal lung tissues, we examined the mRNA expression level of specific cytokines such as CCL4, IL6, and CXCL2. These cytokines were chosen for the analysis since their mRNA expression levels are upregulated in MWCNT-treating macrophages (Sultana et al., 2023). The level of expression of CCL4 markedly decreased in adenocarcinoma compared to that of the control normal lung tissue. In several adenocarcinoma samples, the level of expression of IL6/CXCL2 was higher than that of the control normal lung tissue. In the granuloma sample, the level of IL6 was higher than that of the control normal lung tissue and the level of CCL4/CXCL2 was lower than that of the control normal lung tissue. Taken together, histology specific expression profile of these cytokines may provide additional insights into lung tumorigenesis induced by MWCNT.