Clonality analysis for normal and cancerous colon tissues with human androgen receptor gene polymerase chain reaction

We assessed the feasibility of clonality analysiswith human androgen receptor gene polymerasechain reaction in terms of the sensitivity andspecificity for normal and cancerous colonic tissuestaken from fourteen informative casesselected from 22 women with colonic adenocarcinoma.Ten crypts microdissected from each 10-Òm-thick cryostat sections and whole tissueswere used as samples. DNA was extracted from thesamples and amplified with and without priorenzyme digestion. These products were analyzedby capillary electrophoresis for clonality. Of thewhole-tissue DNA, none of the normal tissues andseven (50.0%) of the cancerous tissues showedmonoclonality. Of the microdissected samples,monoclonality was found in 88.4% (107/121) ofnormal crypts and 95.9% (117/122) of cancerouscrypts. Samples composed of crypts with shortand long alleles were found in eight of the 14 normalcolonic mucosae, but in none of the canceroustissues. We concluded that the sensitivity of thismethod is limited for both whole-tissue DNA andmicrodissected-tissue DNA, because monoclonalityfrom small samples does not always indicatemonoclonality of the entire lesion. The high specificityof this method, however, allows polyclonalresults in whole tissues to be confirmed by additionalanalysis of microdissected tissues.