[Methylation status of the 5' CpG islands in FHIT gene in the plasma and tissues of cervical cancer patients]

To evaluate the methylation status of the 5' CpG islands in FHIT gene using plasma and tissue samples from cervical cancer patients and find a novel marker for non-invasive diagnosis of cervical cancer, methylation-specific PCR (MSP) was employed to examine CpG island methylation in FHIT gene in 151 pretreatment plasma samples and 30 tumor tissue samples obtained from cervical cancer patients. MSP product was cloned and sequenced directly. CpG island methylation of FHIT was detected in 31.13% of the plasma samples, and in 53.33% of the tissue samples. The total concordant rate of methylation status between plasma and tissue samples in FHIT gene was 80.00%. We found a strong positive correlation between FHIT methylation in the plasma and the clinical stage and histological grade of the tumor. The data showed that CpG island methylation of the FHIT gene is prevalent in the plasma and tissue samples from cervical cancer patients. FHIT detection may be used as a non-invasive marker for diagnosis of cervical cancer and prognostic treatment evaluation.