title: AID expression increased by TNF-α is associated with class switch recombination of Igα gene in cancers.
abstract: Recently, immunoglobulins (Igs) were unexpectedly found to be expressed in epithelial cancers. Immunoglobulin class switching or class switch recombination (CSR) is a natural biological process that alters a B cell's production of antibodies (immunoglobulins) from one class to another. However, the mechanism of CSR of Ig genes in cancer is still unknown. Here, we confirmed by detecting the hallmark of CSR that the Igα gene in cancer underwent CSR. Then we focused on activation-induced cytidine deaminase (AID), a crucial factor for initiating CSR. Further studies using tumor necrosis factor (TNF)-α stimulation and specific inhibitor of NF-κB revealed that TNF-α could increase AID expression through NF-κB signaling. Finally, we demonstrated that AID could co-localize with protein kinase A and bind to the switching (Sα) region of the Igα gene. Overexpression of AID obviously enhanced Igα heavy chain expression and its binding ability to the Sα region. These findings indicated that TNF-α-induced AID expression is involved with CSR in cancer.
authors: Laboratory of Tumor Molecular Biology, Cancer Research Institute, Central South University, Changsha, Hunan 410008, China.|Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, Hunan 410008, China.|Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, Hunan 410008, China.
authors: Zhi
authors: Z
authors: Duan
authors: Institutes of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, China.
authors: Hui
authors: H
authors: Zheng
authors: Department of Cardiothoracic Surgery, Center of Clinical Gene Diagnosis and Therapy, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China.
authors: Haidan
authors: H
authors: Liu
authors: Department of Immunology, Xiangya Medical College, Central South University, Changsha, Hunan 410008, China.
authors: Ming
authors: M
authors: Li
authors: Laboratory of Tumor Molecular Biology, Cancer Research Institute, Central South University, Changsha, Hunan 410008, China.|Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, Hunan 410008, China.|Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, Hunan 410008, China.
authors: Min
authors: M
authors: Tang
authors: Laboratory of Tumor Molecular Biology, Cancer Research Institute, Central South University, Changsha, Hunan 410008, China.|Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, Hunan 410008, China.|Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, Hunan 410008, China.
authors: Xinxian
authors: X
authors: Weng
authors: Laboratory of Tumor Molecular Biology, Cancer Research Institute, Central South University, Changsha, Hunan 410008, China.|Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, Hunan 410008, China.|Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, Hunan 410008, China.
authors: Wei
authors: W
authors: Yi
authors: The Hormel Institute, University of Minnesota, Austin, MN 55912, USA.
authors: Ann M
authors: AM
authors: Bode
authors: Laboratory of Tumor Molecular Biology, Cancer Research Institute, Central South University, Changsha, Hunan 410008, China.|Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, Hunan 410008, China.|Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, Hunan 410008, China.
authors: Ya
authors: Y
authors: Cao
mesh_terms: D045744:Cell Line, Tumor; D003564:Cytidine Deaminase / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D006801:Humans; D017578:Immunoglobulin Class Switching / Q000235:genetics*; D007136:Immunoglobulins / Q000235:genetics*; D016328:NF-kappa B / Q000378:metabolism; D009369:Neoplasms / Q000235:genetics*; D011995:Recombination, Genetic; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D000098830:AICDA (Activation-Induced Cytidine Deaminase)
chemical_list: D007136:Immunoglobulins; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D000098830:AICDA (Activation-Induced Cytidine Deaminase); D003564:Cytidine Deaminase