Objective: To screen the specific molecular maker of invasive hydatidiform moles (HM) by differential display analysis.
Methods: For dot hybridization, about 1.0 microg of each cDNA sample of invasive and non-invasive HM were labeled as probes using the Dig DNA labeling and Detection Kit (Boehringer Mannheim). The specific expression fragments of invasive HM recovered from PAGE gel were re-amplified by PCR, and the PCR products were dotted onto nylon membrane and hybridized by two probes of invasive and non-invasive HM cDNA respectively. Some fragments with a strong positive hybridization signal were cloned into the polylinker of lasmid PUC19 and were sequenced. The fragments' sequences were searched for homology in the NCBI data using the BLAST (Database: GenBank Human EST entries; Posted date:Aug 31, 2004; Number of letters in database: 1,697,659,032; Number of sequences in database: 3,677,722).
Results: The 20 fragments in 28 bands with specific expression in invasive HM were re-amplified, of which 13 showed positive hybridization signals, and 3 were cloned into the polylinker of lasmid PUC19. A fragment in the 3 was a new expressed sequence tag (EST) and the sequence was submitted to NCBI data (dbEST_Id: 10875704; GenBank_Accn: BM403211).
Conclusion: There are more differences in gene expression between invasive and non-invasive HMs, and differential display analyses are of a potential significance to early diagnosis of invasive HM.