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 cel...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 Iggenes in cancer is still unknown. Here, we confirmed by detecting the hallmark of CSR that the Iga 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-KB 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 Sa region. These findings indicated that TNF-α-induced AID expression is involved with CSR in cancer.展开更多
文摘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 Iggenes in cancer is still unknown. Here, we confirmed by detecting the hallmark of CSR that the Iga 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-KB 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 Sa region. These findings indicated that TNF-α-induced AID expression is involved with CSR in cancer.
