SSCP and Sequence Analysis of p53 Mutations in Ovarian Tumors

The p 53 tumor suppressor gene encodes a 53-kD nuclear phosphoprotein and is the most commonly altered gene in human cancers (1 ). There are a large variety of methods currently employed for detection of alterations in thep53 gene. The reported abnormalities in p 53 have been detected with a variety of techniques including immunohistochemical staining (IHCS) as a primary screening modality and less frequently single-strand conformation polymorphism (SSCP) screening. However, certain mutations such as frameshift mutations may not be detectable by IHCS, and most studies using SSCP have limited their search to exons 5-8 (2 ). As shown previously by our lab, this strategy can lead to underreporting of the true frequency of p 53 null mutations (3 ). We routinely perform a complete evaluation of the p 53 open reading frame (exons 2-11) using SSCP analysis with an estimated sensitivity of over 90% (3 ). This approach significantly enhances the detection of null mutations, especially insertion/deletion type mutations.