DEMONSTRATION OF CD44 GENE-EXPRESSION IN CELLS FROM FINE-NEEDLE ASPIRATES OF BREAST-LESIONS BY THE POLYMERASE CHAIN-REACTION

Aim - To demonstrate the feasibility of studying specific gene express ion in fine needle aspirates from clinical lesions. The reverse transc ription/polymerase chain reaction (RT-PCR) technique was used to demon strate CD44 gene expression in cells from diagnostic fine needle aspir ates taken from patients attending the outpatient clinic for breast di seases. Methods-Polyadenylated RNA was extracted from the cells remain ing in the syringe barrel after fine needle aspirate cytological diagn osis of 41 patients with breast lesions. Analysis of CD44 gene express ion was performed by RT-PCR using primers flanking the site for insert ion of the variant exons. The resulting products were separated on 1.2 % agarose gels, transferred to nylon membranes using Southern blotting and hybridised with specific probes for standard (constitutive) and v ariant exons of this gene. Results - On hybridisation with the CD44 st andard exon probe, the expected amplified product of approximately 482 base pairs was visualised in 22 of 41 samples examined. Further hybri disation with the ((variant)) exon probes (exons 7 (v2), 8 (v3), 9b (v 4), 12 (v7), and 15 (v10)) on 12 of these samples showed the presence of large molecular variants in all of these samples. However, the expr ession pattern detected with the probes for exons 7 (v2), 8 (v3) and 9 b (v4) differed among the patients. Conclusions-Expression of the stan dard and variant regions of the CD44 gene in cells remaining in the sy ringe after fine needle aspiration was demonstrated using RT-PCR. The 5' variant exon probes seemed to show different patterns of expression among the patients. Further studies are currently being conducted to determine whether there is any correlation between expression of the v arious components of this gene and cytological diagnosis. Using this m ethod, it would be possible to study the expression of other candidate marker genes in breast cancer using fine needle aspirates.