胃癌癌前病变的研究进展及防治对策

MNNG在大鼠胃癌前期病变造模中的量效关系

目的

观察N-甲基-N'-硝基-N-亚硝基胍(N-methyl-N'-nitro-N-nitrosoguanidine, MNNG)不同的给药途径和剂量对SD大鼠胃癌前期病变造模中的胃黏膜组织的病理学影响.

方法

150只体质量80-100 g的SD♂大鼠随机分成6组, 空白对照自由饮组, 空白对照灌胃组, MNNG低浓度组, MNNG中浓度组, MNNG高浓度组, MNNG灌胃组, 各组均为25只. 低、中、高浓度组分别采用50、100、150 μg/mL的MNNG自由饮, 3组联合使用高Na饮水(15%NaCl饮水)、饥饱失常、雷尼替丁加工饲料造模; 灌胃组在低浓度组的基础上, 每日以0.017 mol/L的MNNG溶液灌胃(根据不同时期体质量计算灌胃量). 连续28 wk, 比较各组大鼠的一般情况、组织病理学变化情况, 并且运用免疫组织化学的方法, 测定各组胃黏膜组织Bcl-2的表达.

结果

低浓度组大鼠, 鳞状上皮改变较多, 发生率为28%, 仅炎性改变的为11例; 中浓度组大鼠, 萎缩肠化的发生率为65.2%, 少数发生鳞状上皮改变; 高浓度组大鼠发生萎缩、肠化、鳞状上皮化生以及癌变(鳞癌), 其中癌变率为33.4%, 诱变率为85.7%; 灌胃组大鼠, 在低浓度组的基础上, 每日以0.017 mol/L的MNNG溶液灌胃(根据不同时期体质量计算灌胃量), 发生萎缩、肠化、鳞状上皮化生以及癌变, 诱变率为84.2%. 免疫组织化学法检测Bcl-2, 呈现与MNNG造型药物浓度相关的高表达.

结论

在MNNG的诱导下, 联合饲喂雷尼替丁饲料、饥饱失常、高Na饮水、灌胃, 可以成功诱导出大鼠萎缩、肠化、萎缩伴肠化的模型.

Understanding the promising role of TCM in gastric cancer treatment and prevention from the perspective of TCM physical constitution theory

Traditional Chinese medicine (TCM) is an important component of comprehensive therapies in gastric cancer. Previous studies have shown that TCM can reduce the side effects of chemotherapy, and prevent and delay the recurrence and metastasis in gastric cancer patients after surgery. However, the population for which TCM treatment is indicated is still undefined. Recently, the physical constitution has been proved to be closely related to pathogenic factors of the body, therapeutic sensitivity and prognosis. To define the population for which TCM treatment is indicated from the perspective of TCM physical constitution theory will help understand the important role of TCM in the prevention and treatment of gastric cancer.

Jiedu Huayu Jianpi Fang induces demethylation and increased expression of p16 and PTEN genes in gastric dysplasia in rats

AIM: To observe the effect of Jiedu Huayu Jianpi Fang (JHJF) on the methylation status and expression of cyclin-dependent kinase inhibitor 2A (p16) and phosphatase and tensin homolog (PTEN) in rats with gastric dysplasia (GD), and to explore the therapeutic effect of JHJF on GD.

METHODS: A low concentration of N-methyl -N'-nitro-N-nitrosoguanidine (MNNG)-based modeling method was adopted to induce GMD, and model rats were randomly divided into a model control group, a retinoic acid treatment group, and a JHJF treatment group. Normal rats treated with JHJF were used as positive controls. Methylation specific PCR was used to detect the methylation status of p16 and PTEN genes in gastric mucosal cells, and real-time PCR, Western blot and immunohistochemistry were used to detect the mRNA and protein expression of p16 and PTEN.

RESULTS: The rates of p16 and PTEN gene methylation in the model control group were both 33.33% (6/18), higher than those in the normal control group 20% (2/10), but the differences were not significant. In the JHJF treatment group, the rates of p16 and PTEN gene methylation were both 0% (0/15), significantly lower than those in the model control group (33.33%, 6/18). The expression levels of p16 and PTEN mRNAs (P < 0.001, P < 0.05) and proteins (P < 0.01 for both) were significantly higher in the JHJF treatment group than in the model control groups.

CONCLUSION: JHJF can induce demethylation and increase expression of the p16 and PTEN genes in GD in rats. JHJF has a potential value for the treatment of GD.

Advances in development of animal models of chronic atrophic gastritis

Chronic atrophic gastritis (CAG) is a precancerous disease whose research and treatment has attracted much attention. Development of animal models of CAG is very important for the research of this disease. Wistar rats and SD rats are mainly experimental animals used for modeling; however, the age and sex of these animals differ among different studies, although many scholars believe that these factors might affect experimental results. Helicobacter pylori is a common risk factor for CAG and can be used to create CAG model successfully, but this method is time-consuming and the induced pathological changes are not stable. N-methyl-N'-nitro-N-nitrosoguanidine, ammonia, sodium deoxycholate, and sodium salicylate are currently commonly used substances for inducing CAG. These substances can be used either alone or in combination to induce CAG successfully; however, the consistent dosage and perfusion time standards have not been established. In addition, combination of disease and syndrome by traditional Chinese medicine can also be used to model CAG. This article reviews recent advances in the development of animal models of CAG.

Factors related to rate of Helicobacter pylori infection in patients with upper gastrointestinal tract diseases in Yili

AIM: To investigate the status of Helicobacter pylori (H. pylori) infection in patients with upper gastrointestinal tract diseases in Yili, Xinjiang.

METHODS: A total of 3925 patients with upper gastrointestinal symptoms, including 2183 males and 1742 females, were included in the study. All patients received gastroscopy and ¹⁴C-UBT. The rate of H. pylori infection was calculated. The effect of disease type, gender, age, ethnicity, occupation and living region on the rate of H. pylori infection was analyzed.

RESULTS: The overall rate of H. pylori infection was 50.57%, obviously lower than that ten years ago. The rate of H. pylori infection was different among each age group. Han nationality patients had a lower rate of H. pylori infection than minority patients. Rural residents had a higher rate of H. pylori infection than urban and suburban residents.

CONCLUSION: H. pylori infection is closely related to ethnicity, living area, age, economic level, and environment in patients with upper gastrointestinal tract diseases in Yili.