How is it possible to prevent gastric mucosal injury and remnant cancer after distal gastrectomy?

DNA methylation genome-wide analysis in remnant and primary gastric cancers

BACKGROUND

Although primary (PGC) and remnant gastric cancers (RGC) both originate from the same gastrointestinal organ, they have very distinct clinicopathological behaviors. We hypothesized that there would be distinct differences in DNA methylation patterns that would occur during carcinogenesis of RGC and PGC, and that the differences in methylation patterns may help identify the primary factor contributing to chronic inflammation in patients with RGC.

METHODS

We investigated the genome-wide DNA methylation patterns of PGC and RGC tissues from 48 patients using the Infinium HumanMethylation450 Beadchip assay. The results were validated by quantitative methylation-specific PCR (qMSP) in separate, independent cohorts.

RESULTS

We found that in our training cohort of 48 patients, the most variable genes from the gastric cancer tissues identified by the Infinium HumanMethylation450 Beadchip clustered the resultant heatmap into high and low methylation groups. On multivariate analysis, PGCs contributed significantly to the high methylation group (p = 0.004, OR 12.33), which suggested that the promoter methylation status in PGC is higher than that in RGC. Supporting this conclusion was the finding that in a separate qMSP analysis in a test cohort, the EPB41L3 gene, chosen because of its high β value on microarray analysis in the gastric cancer tissues, had significantly higher DNA promoter methylation in cancer tissues in the validation PGC tissues than in RGC.

CONCLUSIONS

This study demonstrated that promoter methylation status in PGC is higher than in RGC. This result may reflect the effects of the absence of Helicobacter pylori on the reduced DNA methylation in the remnant stomach.

Indications for total esophagogastric dissociation in children with gastroesophageal reflux disease

Total esophagogastric dissociation (TED) is used to treat gastroesophageal reflux (GER) after failed fundoplication in neurologically impaired patients. It is now performed for some otherwise healthy patients with severe GER. In this procedure, the gastrointestinal tract is reconstructed in a non-physiological way with a Roux-en-Y esophagojejunal anastomosis and jejuno-jejunostomy. Although TED eliminates almost all GER, some patients experience late complications. In this review, we investigated the long-term outcomes after TED to determine the best indications. In total, 147 neurologically impaired patients and 28 neurologically normal patients were identified. The total rate of complications requiring re-operation was 17.2% in neurologically impaired patients and 32.1% in normal patients, both higher than the rates associated with fundoplication. Although most authors added pyloroplasty when there was a concern of gastric emptying, this sometimes caused bile reflux. Nutritional and metabolic complications, including dumping syndrome and chronic digestive malabsorption, were also reported to occur after TED. TED is an option for the treatment of neurologically impaired patients with recurrent GER after fundoplication or who are at a high risk of recurrence of GER with fundoplication. However, neurologically normal patients who have the ability to obtain nutrition orally should consider options other than TED, as postoperative complications are frequent.

Protective effects of heat shock protein70 induced by geranylgeranylacetone in atrophic gastritis in rats

AIM

To investigate the effect of geranylgeranylacetone (GGA) on the progression of atrophic gastritis in rats and its potential mechanism.

METHODS

Atrophic gastritis was induced in Sprague-Dawley rats with 0.1% ammonia solution, 60% ethanol, and 20 mmol/L deoxycholic acid for 24 weeks. Accompanied by the induction of atrophic gastritis, 200 mg/kg GGA was administered by oral gavage for 8 weeks (weeks 17-24). The histological changes in gastric mucosa were quantitated by the index of inflammation, the gastric mucosal thickness, and the amount of glands of 1 mm horizontal length in antrum. Endogenous heat shock protein (HSP)70 levels and distribution were determined by immunoblotting and immunohistochemistry in gastric mucosa.

RESULTS

GGA alleviated the pathological progression of atrophic gastritis with inflammation relief (inflammation index: 1.40 in the GGA group and 1.65 in the atrophic gastritis group) and glandular restoration (mucosal thickness and quantity of glands: 194.3 microm and 38.7 mm in the GGA group; 123.3 microm and 32.7 mm in the atrophic gastritis group; P<0.05). GGA significantly induced HSP70 synthesis (P<0.05). Moreover, quercetin, an inhibitor of HSP70 expression, aggravated the infiltration of inflammatory cells and glandular loss in the antrum.

CONCLUSION

GGA prevented the progression of atrophic gastritis in rats via the induction of HSP70 expression.