PCR-RFLP studies on chromosome 3p in formaldehyde-fixed, paraffin-embedded cervical cancer tissues

Loss of heterozygosity (LOH) has been extensively studied on the short arm of chromosome 3, and functional proofs have been obtained defining a tumor-suppressor locus at 3p21-22. We examined 31 paraffin-embedded cervical cancer samples for LOH, using 5 PCR-primer pairs, located around 3p21. Allele loss was found in 19 out of the 27 informative samples (70%) while 13 out of 23 informative samples (56%) had LOH located at 3p21-22. More of the human papillomavirus (HPV)-positive samples had LOH compared to the HPV-negative samples, giving only a weak association between loss of allele and HPV integration. Modifications of the DNA in the formaldehyde-fixed samples were detected, and further studies will be required to clarify how such artifacts may affect restriction fragment length polymorphism (RFLP) studies on fixed tissues.