Preliminary study of protein changes in trisomy 21 fetus by proteomics analysis in amniocyte.

OBJECTIVE

To discover the candidate biomarker proteins of trisomy 21 (T21) in amniocytes.

METHODS

Amniocentesis was performed to collect amniotic fluid from women who underwent prenatal diagnosis due to high risk of T21 at 18th to 22nd week of gestation. Amniocyte samples were collected, and karyotyping analysis was used to confirm the chromosomal status (18 samples of T21 amniocytes and 20 samples of chromosomally normal ones). Then, backup samples for cytogenetic test were used in this study. Two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry were employed for proteomic analysis. Subsequently, western blotting and biological informatic analysis were utilized to validate the identified proteins and their functions.

RESULTS

Six proteins were found to be significantly up regulated in T21 amniocytes, and they were calumenin, nucleophosmin, elongation factor 1-beta, cathepsin D, platelet-activating factor acetylhydrolase IB subunit beta, and 14-3-3 protein beta/alpha identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Western blotting analysis confirmed the alterations of nucleophosmin and cathepsin D.

CONCLUSION

These proteins may be involved in the pathogenesis of T21. Further studies exploring the exact role of these proteins were essential.