The role of EXT1 gene mutation and its high expression of calcitonin gene-related peptide in the development of multiple exostosis.

OBJECTIVE: Screening and identifying the gene mutation of EXT1, EXT2 and EXT3 associated with multiple exostosis (ME) and the expression in tumor tissues. METHODS: Nine patients with multiple exostosis were collected and genomic DNA was extracted. Polymerase chain reaction (PCR) amplification and direct sequencing techniques were used to screen all exons, 5' and 3' ends of the EXT1, EXT2 and EXT3 related causative genes. EXT1, EXT2 and EXT3 gene were screened and quantified by RNA-SEQ and RT-qPCR. The concentration of calcitonin gene-related peptide (CGRP) in peripheral blood of tumor patients and normal controls was detected by ELISA. RESULTS: Between the two patients with ME, the EXT1 gene was found in one patient to have c.79 T>A mutation, which caused the change of p.M27T, the non polar methionine was replaced by the high frequency mutation of polar threonine, and the rest of patients was found the splicing mutation c.1284 + 8 delAT of the heterozygosity of the EXT1 gene. The serum CGRP concentration of ME patients (623 + 49 pg/ml) was significantly higher than that of normal controls (196 + 68 pg/ml), and EXT1 mutation patients were also higher than non mutation patients.

Exposure to gastric juice may not cause adenocarcinogenesis of the esophagus.

AIM: To determine the effects of gastric juice on the development of esophageal adenocarcinoma (EAC). METHODS: A animal model of duodenogastroesophageal reflux was established in Sprague-Dawley rats undergoing esophagoduodenostomy. The development of EAC and forestomach adenocarcinoma was investigated 40 wk after the treatment. Intraluminal pH and bile of the forestomach were measured. RESULTS: There were no significant differences in pH (t = 0.117, P = 0.925) or bile (χ² = 0.036, P = 0.85) in the forestomach before and 40 wk after esophagoduodenostomy. There were also no significant differences between the model and controls during esophagoduodenostomy or 40 wk after esophagoduodenostomy. The incidence of intestinal metaplasia (88%) and intestinal metaplasia with dysplasia and adenocarcinoma (28%) in the esophagus in the model was higher than in the controls 40 wk after surgery (χ² = 43.06, P < 0.001 and χ² = 9.33, P = 0.002, respectively) and in the forestomach in the model (χ² = 32.05, P < 0.001 and χ² = 8.14, P = 0.004, respectively). The incidence rates of inflammation in the esophagus and forestomach were 100% and 96%, respectively (χ² = 1.02, P = 0.31) in the model, which was higher than in the esophageal control (6.8%) (χ² = 42.70, P < 0.001). CONCLUSION: Gastric juice exposure may not cause intestinal metaplasia with dysplasia or adenocarcinoma of the forestomach and may not be related to EAC.