A Preliminary Study On The Metaplasia Of Intestinal Epithelium In Gastric

The number of new cases of gastric carcinoma in China accounts for 42% of that in the whold world, and the incidence of gastric carcinoma remains the top 1 in the gastroinrestinal malignancy with the second or third mortality in whole malignant diseases. The pathogenesis of gastric cancer remains elusive. However, gastric intestinal metaplasia (GIM) is considered to be a "key-point" during the development process from gastritis to gastric carcinoma.Gastric intestinal metaplasia is generally classified as complete (type Ⅰ) subgroup and incomplete (type Ⅱ and typeⅢ) subgroup. However, it still remains controversial about the relationship between the subtypes of GIM and gastric cancer. Most researchers agree with the opinion that type Ⅲ GIM has closely relationship to GC. Howerer, results that defined the relationship between GIM and GC were mostly based on the long-term follow-up of a cohort of patients by histological examination of gastric biopsies obtained under upper endoscopy. There is no direct pathological evidence and no systemic investigation about biological markers expressed in GIM. The mechanism of GIM involved in gastric carcinogenesis remains unclear.The aim of the current study was to provide direct pathological evidence for the relationship between GIM and gastric cancer via a new pathological technology, called the "gastric mucosal sausage roll", and further investigate the expression of AQP3、CD24、LGR5 and Ki67 in GIM and their significance. This study will provide preliminary experimental basis for the study of the transformation of GIM to gastric cancer.Methods:The distribution of GIM around GC1. The "gastric mucosa Sausage Rolls" was Designed according to the pathological method of "winding method".2. HE stain was performed to "gastric mucosa Sausage Rolls" tissues from distal gastric carcinoma specimen after radical resection from 16 patients diagnosed as intestinal type of gastric antrum carcinoma to ascertain GIM.3. HID-AB stain was applied to determine the subtypes of GIM.4. The correlations between the incidence, the severity or the subtype of GIM and the distance from GC were evaluated.The expression of AQP3, CD24, LGRR, Ki67 in GIM and their significance1. HID-AB stain was applied to the "gastric mucosa Sausage Rolls" tissues to determine the subtype of GIM.2. The expression of AQP3, CD24, LGR5 and Ki67 in GIM was assayed using immunohistochemistry.3. The correlations between AQP3、CD24、LGR5、Ki67 expression and the severity or subtype of GIM and the distance from GC was analyzed.Results:The distriution of GIM around GC1. GIM was found in all stomach specimens, and 50% of the 192 parts exhibited GIM.2. There was no significant difference in the incidence of GIM with regard to the distance from GC in the posterior gastric wall tissues and the lesser curvature tissues toward the pylorus. However, GIM prevalence displayed remarkable association with the distance from GC in the anterior gastric wall tissues and the lesser curvature tissues toward the cardia.3. Regarding the subtypes of GIM, type Ⅲ GIM was more common in GIM around GC. The incidence and severity of GIM were positively correlated with the distance from GC, the closer to GC, the higher incidence of GIM and the more severity of GIM.The expression of AQP3, CD24, LGRR, Ki67 in GIM and their significance1. AQP3 was found to be expressed specifically in goblet cells in GIM. Its positive expression was correlated with marked GIM and type Ⅲ GIM, however, had no correlation with the distance from GC.2. CD24 was found to be positively expressed in GIM. The positive expression of CD24 showed significant correlation with marked GIM and type Ⅱ GIM, and showed no correlation with the distance from GC.3. LGR5 and Ki67 were found to be expressed in tissues around GC regardless of GIM, and their positive expression showed no correlation with the severity or sub-classifications of GIM and the distance from GC.4. The expression of LGR5 in GIM showed significant correlation with Ki67.Conclusion:1. The "gastric mucosal sausage roll" is useful and feasible method to study the diseases of gastric mucosal.2. This study presents pathological evidence for GIM in the development of intestinal type gastric carcinoma. GIM may be a key process in the carcinogenesis of GC, and marked GIM and type Ⅲ GIM have closely relationship to GC.3. The positive expression of AQP3 in goblet cells and CD24 in GIM, consistent with the fact that AQP3 and CD24 expression has correlation with the severity or subtype of GIM, and that the expression of LGR5 has correlation with Ki67 in GIM, suggests that they may be involved in the development from GIM to GC.4. The combination of the severity or subtype of GIM with molecular markers for GIM endoscopic follow-up, may be conducive to the individual development of GIM surveillance, and may be useful for identifying at-risk patients, although this present study is preliminary.