Screening and Identification Differentially Displayed Genes in Fore Stomach Carcinoma of Mice

Objective： To screen and identify key genes differentially displayed in mouse fore stomach carcinoma, in order to elucidate the molecular mechanism underlying carcinogenesis. Methods： The animal models complied with each period of NIH mouse fore stomach carcinoma induced by N-Nitrososarcosineethylester （NSEE） were used in this study. The mice were euthanized on days 14, 28, 56, 77 and 84, respectively, after NSEE-piped treatment, and classified according to their pathologies. The differentially expressed genes were isolated from both normal and morbid tissues by mRNA differential display technique and screened by using Reverse Northern blot. Bioinformatics were employed to analyze the results observed. After identification, ten fragments were cloned and matched with GENEBANK database through homologous analysis. Results： One gene was found identical to splicing factor 3b subunit 1 （Sf3bl）, while seven fragments hold the homology of known cDNA clones. In contrast, other two fragments had extremely low identity to any genes registered in GENBANK databases. Conclusion： It is the first time to demonstrate in this study that splicing factor3b, subunitl （Sf3bl） is related to mouse fore stomach carcinoma. Furthermore, ESC-3 and ESC-4 are suggested to contribute to the development of mouse fore stomach carcinoma, thus may be candidates of new targets of oncogenes.

EXPRESSION OF PCNA,AKP AND ACP DURING DEVELOPMENT OF MOUSE FORE STOMACH CARCINOMA

Objective： To find out the relationship of the expressions of proliferating cell nuclear antigen （proliferating cell nuclear antigen, PCNA）, alkaline phosphotase （alkaline phosphotase, AKP） and acid phosphotase （acid phosphotase, ACP） with the development of mouse fore stomach cancerization. Methods： The animal models, including the various stages during the development of NIH mouse fore stomach carcinoma, were made by N-Nitrososarcosineethylester （N-Nitrososarcosineethylester, NSEE）. The mice were sacrificed on the 14th, 28th, 42nd, 56th, 70th and 84th days respectively after mice were irrigated with NSEE. The fore stomach was taken out and dissected. The methods of histopathology, immunohistochemistry and isoenzyme electrophoresis were adopted to study the dynamic changes of cell shape and expression of PCNA, AKP and ACP. Results： On the 42nd and 56th days after NSEE treatment, the expression of PCNA increased gradually along with the cancerization. Comparing with the control, there were significant differences （P〈0.05）. On the 70th and 84th days, the expression of PCNA increased further （compared with the control P〈0.01）. The activity of AKP increased gradually along with the cancerization. On the 14th, 28th, 42nd and 56th days, there were significant differences （P〈0.05）; on the 70th and 84th days, the activity of AKP increased further （P〈0.01）. The activity of ACP also increased on the 14th, 28th, 42nd and 56th days, and there were significant differences on the 70th days （P〈0.05） and on the 84th days （P〈0.01） compared with the control. Conclusion： During the carcinogenesis of NIH mouse fore stomach, the expressions of PCNA, AKP and ACP increased gradually and were consisted with the changes of cell shapes.

维甲酸对小鼠前胃癌细胞恶性表型及抑癌基因表达的调控作用

采用全反式维甲酸（ＲＡ）对小鼠前胃癌细胞系进行了体外加药处理及将处理的细胞接种于近交系６１５小鼠皮下的实验观察。结果表明：经维甲酸处理的瘤细胞基本丧失在软琼脂中生长形成集落的能力，将该处理细胞接种于小鼠皮下，可见其自发性转移能力明显降低。ＲＮＡ狭线杂交显示经ＲＡ处理的瘤细胞其抑癌基因ｐ５３和转移抑制基因ｎｍ２３的表达明显增强，提示ＲＡ可能通过调控抑癌基因的表达，降低肿瘤细胞的转移能力。

树突状细胞和基因缺陷腺病毒联合治疗小鼠前胃癌的实验研究

目的观察树突状细胞(den-driticcells,DCs)和基因缺陷腺病毒联合治疗小鼠前胃癌的疗效。方法建立小鼠前胃癌动物模型,在体外分化、诱导DCs;瘤内注射基因缺陷腺病毒,观察肿瘤坏死情况;再在瘤体内注射DCs,观察给药侧瘤体及对侧瘤体体积、小鼠生存情况和特异性细胞毒T淋巴细胞(cytotoxicT-lymphocyte,CTL)活性。结果肿瘤组织局部应用基因缺陷腺病毒后,产生明显坏死;瘤内应用DCs,对侧瘤体体积明显缩小,P=0·000;小鼠的生存率提高,且能产生特异性CTLs,能特异性杀伤小鼠前胃癌细胞,P<0·01。结论DCs和基因缺陷腺病毒联合治疗可抑制小鼠前胃癌生长,诱导机体特异性抗肿瘤免疫反应,二者联合应用,可产生协同效应并加强其抗肿瘤效果。