Cell proliferation of esophageal squamous epithelium in erosive and non-erosive reflux disease

AIM： To elucidate cell proliferation in erosive reflux disease （ERD） and non-erosive reflux disease （NERD）, we evaluated markers in squamous epithelial cells.METHODS： Thirty-four consecutive patients with gas- troesophageal-reflux-disease-related symptoms （21 NERD and 13 ERD） were evaluated for the enrolment into the study. All patients underwent 24-h pH moni- toring, standard endoscopy, and biopsy for histological evaluation. The expression of cyclins D and A was eval- uated by real-time reverse transcription polymerase chain reaction （RT-PCR） from isolated epithelial cells. In all samples, analysis of the isolated cell population revealed the presence of epithelial cells only.RESULTS： Real-time RT-PCR showed that, in patientswith ERD, the relative expression of cyclin D1 mRNA in esophageal epithelium was strongly decreased in comparison with NERD patients. The mean value of relative expression of cyclin D1 mRNA in NERD patients was 3.44 ± 1.9, whereas in ERD patients, it was 1.32 ± 0.87 （P = 0.011）. Real-time RT-PCR showed that, in patients with ERD, relative expression of cyclin A mRNA in esophageal epithelium was decreased in comparison with that in NERD patients （2.31 ± 2.87 vs 0.66 ± 1.11）. The mean bromodeoxyuridine labeling index in the NERD patients was 5.42% ± 1.68%, whereas in ERD patients, it was 4.3% ± 1.59%.