Analysis the function of the differentially expressed chemokine receptor 3 in a chronic pneumonia-induced lung cancer model

LI Jie; XIA Dong; YANG Qiuting; WANG Jing; YANG Huiling

doi:10.20227/j.cnki.2096-3610.2026.01.003

Abstract：Objective To develop murine models of lung cancer induced by chronic inflammation and carcinogens,and investigate the key role of chemokine receptor 3(CXCR3)in the progression of lung cancer induced by chronic inflammation.Methods Thirty-four female A/J mice were randomly divided into two groups:a control group(n=17,treated with intratracheal instillation of normal saline),and a treatment group(n=17,treated with intratracheal instillation of 0.5 μg/g lipopolysaccharide(LPS)),both treatments were lasted for 6 weeks.Three mice were randomly selected from each group to evaluate the effects of pneumonia modeling.During the lung cancer treatment phase,the control group was randomly divided into a blank control(NC)group(n=7)and a 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone(NNK)group(n=7).Similarly,the treatment group was randomly divided into an LPS group(n=7)and an LPS-NNK group(n=7).The NC and LPS groups were intraperitoneally injected with normal saline,whereas the NNK and LPS-NNK groups were injected with NNK(3 mg per mouse)for lung cancer modeling.The dosing was administered every two weeks for a total period of four weeks.After the tumor-bearing period,mice underwent lung tissue sampling.Surface pulmonary tumor nodules were counted,pathological changes were evaluated by HE staining,and the expression levels of interleukin 1β(IL-1β)and the cellular transforming proto-oncogene(KRAS)in lung tissue were measured via q RT-PCR.Differentially expressed genes were identified through transcriptome sequencing and differential analysis.Flow cytometry was used to evaluate the effect of the differentially expressed gene CXCR3 on the cell cycle.Western blot was performed to compare the protein expression levels of cyclin D1(CCND1),cyclin-dependent kinase inhibitor 1(P21),X-Ray Repair Cross Complementing 5(XRCC5),and phosphorylated H2A.X Variant Histone(γH2AX)following gene silencing.Results Compared to the NC and LPS groups,the lung cancer incidence in the NNK and LPS-NNK groups reached 100%.The average number of tumor cancer nodules in the LPS-NNK group was significantly higher than that in the NNK group(P<0.000 1).In comparison to the NC group,the differences in IL-1β and KRAS expression levels among the LPS,NNK,and LPS-NNK groups were statistically significant(P<0.01).The candidate gene CXCR3 was identified through transcriptome sequencing,differential analysis,and other methods.After CXCR3 knockdown,the proportion of cells significantly decreased in the G1 phase,and notably increased in the S phase(P<0.05).Protein analysis revealed a downregulation in the expression of CCND1 and XRCC5,alongside an upregulation in the expression of P21 and γH2AX(P<0.05).Conclusion CXCR3 is potentially a pivotal regulatory factor in the malignant transformation of lung cancer induced by chronic inflammation.