Paired box protein Pax-8(PAX8) is a member of the PAX family of transcription factors. It essential of organogenesis during embryonic development of the kidney , thyroid and paramesonephric ducts,giving rise to urogenital organs including the seminal vesicals, vas deferens, ureter , fallopian tibes. Although PAX8 is crucial for organogenesis, sustained expression in the normal kidney ,thyroid , breast , seminal vesicles , ovarian ,cervical and endometrial epithelia suggest a role for homeostatic control of mature tissues. Immunohistochemical staining revealed almost exclusive nuclear localization, with low or negligible cytoplasmic expression. Due to the restrictive expression in normal tissues,Pax8 has been suggested to be a sensitive and specific marker for both primary and metastatic tumors derived from the above mentioned organs and tissues ,PAX8 is expressed in renal cell carcinoma of clear cell,papillary and chromophobe subtypes . It is also found in endometroid carcinoma,serous carcinoma and thyroid carcinomas. However ,PAX8 expression in lymphoid tissue has been controversial.The N-terminal of polyclonal PAX8 antibody was found to cross-react with PAX5; previous data suggesting the use of PAX8 for diagnosis of malignant lymphomas should be reevaluated. The cause may be due to substantial sequence homology in the N-terminus of PAX8 and PAX5(70%).
Paired box protein Pax-8(PAX8) is a member of the PAX family of transcription factors. It essential of organogenesis during embryonic development of the kidney , thyroid and paramesonephric ducts,giving rise to urogenital organs including the seminal vesicals, vas deferens, ureter , fallopian tibes. Although PAX8 is crucial for organogenesis, sustained expression in the normal kidney ,thyroid , breast , seminal vesicles , ovarian ,cervical and endometrial epithelia suggest a role for homeostatic control of mature tissues. Immunohistochemical staining revealed almost exclusive nuclear localization, with low or negligible cytoplasmic expression. Due to the restrictive expression in normal tissues,Pax8 has been suggested to be a sensitive and specific marker for both primary and metastatic tumors derived from the above mentioned organs and tissues ,PAX8 is expressed in renal cell carcinoma of clear cell,papillary and chromophobe subtypes . It is also found in endometroid carcinoma,serous carcinoma and thyroid carcinomas. However ,PAX8 expression in lymphoid tissue has been controversial.The N-terminal of polyclonal PAX8 antibody was found to cross-react with PAX5; previous data suggesting the use of PAX8 for diagnosis of malignant lymphomas should be reevaluated. The cause may be due to substantial sequence homology in the N-terminus of PAX8 and PAX5(70%).