Objective: To investigate the use of maternally expressed, imprinted genes for the differential diagnosis of complete hydatidiform mole (CHM) and partial hydatidiform mole (PHM).
Study design: Expression patterns of imprinted genes in CHM were validat ed by microarray analysis. Twenty CHMs and 10 PHMs were then subjected to Western blot analysis and immunostaining with appropriate antibodies.
Results: TSSC3 (also known as PHLDA2, IPL), SLC22A1L, KCNQ1 and decorin were shown to be down-regulated, with the suppression of TSSC3 most marked. In all 20 CHM cases for which the diagnosis had been confirmed by DNA polymorphic markers, the expression of TSSC3 was completely lost on Western blots. In contrast, in 10 PHMs that had also been diagnosed by DNA analysis, TSSC3 was expressed normally. Immunohistochemistry showed an identical result.
Conclusion: Complete silencing of TSSC3 expression in CHM offers a convenient and novel diagnostic strategy for diagnosing molar lesions.