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Objective To explore the expression of methyl CpG binding protein 2 (MeCP2) in gastric cancer tissues and its role in multi-drug resistance (MDR) in gastric cancer cells.Methods The expression of MeCP2 in 90 gastric cancer tissues and the adjacent normal tissues was detected by immunohistochemistry,and the relationship between MeCP2 expression level and clinicopathological parameters was analyzed.The expression level of MeCP2 in gastric cancer cell line SGC7901,MDR cell variants SGC7901/doxorubicin hydrochloride(ADR) and SGC7901/vincristine(VCR)was determined by Western blot.After the expression of MeCP2 was silenced by short interference RNA (siRNA),half inhibitory concentration (IC50) of 5-fluorouraeil and cisplatin in gastric cancer cell was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide(MTT) assay.The t test or chi square test was performed for statistical analysis.Results The positive rate of MeCP2 expression in gastric cancer tissues was 72.2％ (65/90),which was significantly lower than that in adjacent normal tissues (93.3％,84/ 90),and the difference was statistically significant (x2 =14.068,P＜0.01).MeCP2 expression was not correlated with age,tumor maximum diameter and lymph node metastasis (all P＞0.05),however which was related to gender,clinical TNM stages and distant metastasis (x2=4.680,4.186 and 4.327;aH P＜ 0.05).The gray scale ratios of MeCP2/β-actin in SGC7901/ADR and SGC7901/VCR were 0.593 7 ± 0.030 5 and 0.651 2 ± 0.018 6,which were lower than that of parental SGC7901 cells (1),and the differences were statistically significant (t =23.080,17.360;both P ＜ 0.01).After the expression of MeCP2 was silenced by siRNA,the IC50 of 5-fluorouracil and cisplatin in SGC7901 transfected with MeCP2 specific siRNA were (11.540 0±0.469 3) μg/mL and (2.273 0±0.265 4) μg/mL,which were higher than the IC50 of 5-fluorouracil and cisplatin in SGC7901 transfected with non-related oligonucleotide sequence ((8.663 0±0.160 1) μg/mL and (0.884 0 ±0.038 6) μg/mL),respectively.The differences were statistically significant (t =15.380 and 8.153;both P ＜ 0.01).Conclusions The expression of MeCP2 in gastric cancer tissues significantly decreased,which was correlated with clinical stages,distant metastasis.MeCP2 can inhibit the MDR of gastric cancer cell,which indicated the dysregulated expression of MeCP2 might participate in the genesis and development of gastric cancer.
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Objective To analyze clinical pathological characteristics of gastric cancer in elderly people,and to study the characteristics of gastric cancer incidence.Methods A retrospective analysis of clinical data of gastric cancer in elderly people which were diagnosed by gastroscopy and pathology from 2003 to 2008 was undertaken,and compared to it in young people at the same period about gender,clinical symptoms,lesion,pathological types.Results There were 70 cases of men(77.8%)and 20 cases of woman(22.2%)in elderly group,but there were 3 cases of man(25.0%)and 9 cases of woman(75.0%)in young group,there wsa significant difference between two group(P ＜0.01);The first symptoms in elderly group and young group were loss of appetite(50 cases,55.6% and 1 case,8.3%),thin and weak(38 cases,42.2% and 1 case,8.3%).difficulty swallowing(23 cases,25.6% and o case),anehia(29 cases ,32.2% and 2 cases,16.7%),upper abdominal pain(34 cases,37.1 % and 4 cases,33.3%)re spedtively.There was no significant difference between two group(P ＞ 0.05).The lesion of gastric cancer in two group were funds of stomach and cardia(39 cases,43.3% and 1 case,8.3%),antral(26 cases,28.9% and 7 cases,58.3%).body of stomach(22 cases,24.4% and 4 cases,33.3%).entire stomach(3 cases,3.3% and 0 case)respectively.There was significant difference between two group(P ＜0.05).The main of pathological types was abeno carcinoma.and the main in elderly group was moderate,high differentiation(85%),and the main in young group was moderate,low differentiation(59%).There was significant difference between two group(P ＜ 0.05).Conclusions The symptoms of gastric cancer in elderly people was non-specific,and it had more complications.We found that early diagnosis of gastric cancer in elderly people was difficult and it had poor prognosis.
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Objective To study the expressions of caudal type homeodomain transcription factors CDX1 and CDX2 in different subtype of intestinal metaplasia (IM) and gastric eareinoma,and investigate their roles in the development and progression of IM and gastric carcinogenesis, and determine the relationship between IM and gastric carcinoma. Methods Forty eases of chronic superficial gastritis, 40 cases of chronic atrophic gastritis (CAG), 46 eases of CAG with IM, 40 cases of gastric carcinoma, and 32 eases of IM foci in para-eancerous tissues were selected respectively to construct tissue microarrays. Immunohistechemistry and in situ hybridization were used to assess the expressions of CDX2 protein and CDX1, CDX2 mRNA in different gastric lesions respectively. Results The proportion of type Ⅲ IM in IM foci in para-caucerous tissues was significantly higher than that in CAG (56.25% vs 21.74% ,P< 0.01). There was no expression of CDX1, CDX2 mRNA and CDX2 protein in chronic superficial gastritis and CAG without IM. The expression of CDX2 protein and CDX2 mRNA in CAG with IM, para-cancerous tissues and gastric carcinoma was 69.57%, 53.12%,42.50% (CDX2 protein) and 63.04%,46.88%,35.00% (CDX2 mRNA), respectively. The exprossions of CDX1 mRNA in above throe gastric lesions were 67.39%, 50.00%, 40.00%, respectively. The expressions of CDX2 protein and CDX2, CDX1 mRNA in gastric carcinoma were significantly lower than those in CAG with IM (P< 0.01). But there was no significant difference between gastric carcinoma and IM foci in para-cancerous tissues (P> 0.05). Furthermoro,the expressions of CDX2 protein were significantly associated with histological type of gastric carcinoma, which in intestinal-type was significantly higher than those in diffuse-type(54.55% vs 27.78%, P< 0.05). The expression of CDX2 protein in type Ⅲ IM was also significantly lower than that in type Ⅰ IM(46.43% vs 79.31%,P< 0.05). Conclusions CDX1 and CDX2 may play important roles in the development and progression of IM and gastric carcinoma, and may be new gastric carcinoma associated genes. Type Ⅲ IM is a precancerous lesion of the intestinal-type gastric carcinoma.
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Objective To investigate effects of octreotide combined with aspirin on the growth and metastasis of gastric cancer in vivo. Methods SGC-7901, human gastric cancer cell line, was implanted orthotopically in the stomach of nude mice. Octreotide or aspirin alone and the combination of the two drugs were administrated for 8 weeks to investigate the effects of them on tumor growth and metastasis. Results At necropsy, xenografts in situ were found in all stomachs of nude mice except two nude mice in the combined group. The mean volume and weight of tumors in nude mice treated with octreotide or aspirin were significantly lower than those of control group. The inhibitory rate for tumors was 60.6% in octreotide group, 39.3% in aspirin group and 85.6% in the combined group with octreotide and aspirin respectively. The metastatic rates of gastric adenocarcinoma were markedly lower in any of treatment group than that in control group. No severe side action was observed in all of treatment group. Conclusion Octreotide combined with aspirin greatly enhanced the anti-growth effect on gastric cancer in vivo when compared to using either of them and inhibited the metastasis of gastric adenocarcinoma in nude mice.