title: Non-small-cell lung cancer-induced immunosuppression by increased human regulatory T cells via Foxp3 promoter demethylation.
abstract: Patients with non-small-cell lung cancer (NSCLC) have immune defects that are poorly understood. Forkhead box protein P3 (Foxp3) is crucial for immunosuppression by CD4(+) regulatory T cells (Tregs). It is not well known how NSCLC induces Foxp3 expression and causes immunosuppression in tumor-bearing patients. Our study found a higher percentage of CD4(+) Tregs in the peripheral blood of NSCLC compared with healthy donors. NSCLC patients showed demethylation of eight CpG sites within the Foxp3 promoter with methylation ratios negatively correlated with CD4(+)CD25(+)Foxp3(+) T levels. Foxp3 expression in CD4(+) Tregs was directly regulated by Foxp3 promoter demethylation and was involved in immunosuppression by NSCLC. To verify the effect of tumor cells on the phenotype and function of CD4(+) Tregs, we established a coculture system using NSCLC cell line and healthy CD4(+) T cells and showed that SPC-A1 induced IL-10 and TGF-β1 secretion by affecting the function of CD4(+) Tregs. The activity of DNA methyltransferases from CD4(+) T was decreased during this process. Furthermore, eight CpG sites within the Foxp3 promoter also appeared to have undergone demethylation. Foxp3 is highly expressed in CD4(+) T cells, and this may be caused by gene promoter demethylation. These induced Tregs are highly immunosuppressive and dramatically inhibit the proliferative activity of naïve CD4(+) T cells. Our study provides one possible mechanism describing Foxp3 promoter demethylation changes by which NSCLC down-regulates immune responses and contributes to tumor progression. Foxp3 represents an important target for NSCLC anti-tumor immunotherapy.
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, No. 300 of Guangzhou Road, Nanjing, 210029, China.|National Key Clinical Department of Laboratory Medicine, No. 300 of Guangzhou Road, 210029, Nanjing, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Ke
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, No. 300 of Guangzhou Road, Nanjing, 210029, China.|National Key Clinical Department of Laboratory Medicine, No. 300 of Guangzhou Road, 210029, Nanjing, China.
authors.forename: Shuping
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, No. 300 of Guangzhou Road, Nanjing, 210029, China.|National Key Clinical Department of Laboratory Medicine, No. 300 of Guangzhou Road, 210029, Nanjing, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, No. 300 of Guangzhou Road, Nanjing, 210029, China.|National Key Clinical Department of Laboratory Medicine, No. 300 of Guangzhou Road, 210029, Nanjing, China.
authors.forename: Genyan
authors.initials: G
authors.lastname: Liu
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, No. 300 of Guangzhou Road, Nanjing, 210029, China.|National Key Clinical Department of Laboratory Medicine, No. 300 of Guangzhou Road, 210029, Nanjing, China.
authors.forename: Lixia
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, No. 300 of Guangzhou Road, Nanjing, 210029, China.|National Key Clinical Department of Laboratory Medicine, No. 300 of Guangzhou Road, 210029, Nanjing, China.
authors.forename: Erfu
authors.initials: E
authors.lastname: Xie
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, No. 300 of Guangzhou Road, Nanjing, 210029, China.|National Key Clinical Department of Laboratory Medicine, No. 300 of Guangzhou Road, 210029, Nanjing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Gao
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, No. 300 of Guangzhou Road, Nanjing, 210029, China.|National Key Clinical Department of Laboratory Medicine, No. 300 of Guangzhou Road, 210029, Nanjing, China.
authors.forename: Daqian
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, No. 300 of Guangzhou Road, Nanjing, 210029, China.|National Key Clinical Department of Laboratory Medicine, No. 300 of Guangzhou Road, 210029, Nanjing, China.
authors.forename: Ruihong
authors.initials: R
authors.lastname: Sun
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, No. 300 of Guangzhou Road, Nanjing, 210029, China. wangfang@njmu.edu.cn.|National Key Clinical Department of Laboratory Medicine, No. 300 of Guangzhou Road, 210029, Nanjing, China. wangfang@njmu.edu.cn.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, No. 300 of Guangzhou Road, Nanjing, 210029, China. sypan@njmu.edu.cn.|National Key Clinical Department of Laboratory Medicine, No. 300 of Guangzhou Road, 210029, Nanjing, China. sypan@njmu.edu.cn.
authors.forename: Shiyang
authors.initials: S
authors.lastname: Pan
mesh_terms: D000328:Adult; D000368:Aged; D015153:Blotting, Western; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D018920:Coculture Techniques; D018899:CpG Islands / Q000235:genetics / Q000276:immunology; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D019175:DNA Methylation / Q000235:genetics / Q000276:immunology*; D000090205:DNA Methyltransferase 3A; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance / Q000235:genetics / Q000276:immunology*; D016753:Interleukin-10 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008175:Lung Neoplasms / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: C000717967:DNMT3A protein, human; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053773:Transforming Growth Factor beta1; D016753:Interleukin-10; D004248:DNA (Cytosine-5-)-Methyltransferases; D000090205:DNA Methyltransferase 3A
keywords: DNA demethylation; Forkhead box protein P3; Immunosuppression; Non-small-cell lung cancer; Regulatory T cells