白细胞介素4基因转移的肿瘤细胞体外生物学特性及体内致瘤性的研究

观察了白细胞介素４（ＩＬ－４）基因转移的肿瘤细胞体内致瘤性的变化。构建了含５００ｂｐ的小鼠ＩＬ－４ｃＤＮＡ的真核表达载体ＢＭＧＮｅｏ－ＩＬ－４．用该表达载体将ＩＬ－４基因转移至小鼠Ｂ１６黑色素瘤细胞，通过Ｇ４１８抗性筛选、有限稀释法及ＩＬ－４活性检测，获得了高分泌ＩＬ－４的黑色素瘤细胞克隆株并经Ｎｏｒｔｈｅｒｎ印迹鉴定，将其接种于小鼠皮下后观察到肿瘤生长缓慢、小鼠存活期延长，表明高分泌ＩＬ－４的细胞克隆株体内致瘤性显著下降。该结果为进一步研究肿瘤的ＩＬ－４基因治疗打下了基础。     

转染 p53基因对肺腺癌细胞株裸鼠 移植瘤生长的影响

目的：探讨转染野生型 p53（ wt-p53）和突变型 p53（ mt-p53）基因对人肺腺癌细胞株 GLC-82裸鼠移植瘤生长的影响。方法：采用脂质体介导法,分别将 wt-p53和 mt-p53基因导入人肺腺癌细胞株 GLC-82,在裸鼠体内、体外实验中检测转导细胞的生长状况和裸鼠致瘤性。结果：转染 mt-p53 基因的细胞株 G418筛选的细胞集落数、 3H-TDR掺入实验、软琼脂平皿细胞集落数,以及裸鼠瘤组织重量和体积均高于对照组（ P<0.01）,而转染 wt p53基因的细胞株均显著低于对照组（ P< 0.01）,表明导入 wt p53基因的细胞株瘤细胞生长速度明显低于对照组细胞株和导入 mt p53基因的细胞株,即导入 mt p53基因的细胞株瘤细胞生长速度最快,而导入 wt p53基因的细胞株瘤细胞生长速度最慢。结论： wt p53基因能有效抑制人肺腺癌细胞生长; mt p53基因则可以明显地促进瘤细胞生长。     

Suppression of human nasopharyngeal carcinoma cell growth in nude mice by the wild-type p53 gene

Summary Wild-type and mutant human p53 genes were transfected into the nasopharyngeal carcinoma (NPC) cell line CNE-3. Tumorigenicity in nude mice showed that the tumor resulting from the cells transfected with the wild-type p53 gene grew more slowly and was smaller than that from the cells transfected with mutant p53 gene and that from control CNE-3 cells. In contrast, the tumor from the cells transfected with the mutant p53 gene grew faster than that produced by cells transfected with the wild-type p53 gene and that produced by control CNE-3 cells. The results demonstrate that the wild-type p53 gene could inhibit the NPC cell growth in nude mice and the mutant p53 gene could enhance the NPC cell growth in nude mice. The p53 gene may also play an important role in the pathogenesis of NPC.Abbreviation NPC nasopharyngeal carcinoma     

Input of microenvironmental regulation on colorectal cancer: Role of the CCN family

Colorectal cancer(CRC)is a major health problem causing significant morbidity and mortality.Previous results from various studies indicate that CRC tumorigenicity encompasses tumor microenvironment,emphasizing the complex interacting network between cancer cells and nearby host cells,which triggers diverse signaling pathways to promote the growth and spread ofcancer cells.The CCN family proteins share a uniform modular structure,mediating a variety of physiological functions,including proliferation,apoptosis,migration,adhesion,differentiation,and survival.Furthermore,CCN proteins are also involved in CRC initiation and development.Many studies have shown that CCN members,such as CCN1,CCN2,CCN3,Wnt-induced secreted protein(WISP)-1,WISP-2,and WISP-3,are dysregulated in CRC,which implies potential diagnostic markers or therapeutic targets clinically.In this review,we summarize the research findings on the role of CCN family proteins in CRC initiation,development,and progression,highlighting their potential for diagnosis,prognosis,and therapeutic application.     

裸鼠高致瘤性K562-n细胞系代谢相关基因表达变化的研究

目的　探索K5 6 2和K5 6 2 n细胞在裸鼠体内致瘤性不同的分子生物学机制。方法　应用基因芯片技术 ,检测K5 6 2细胞和K5 6 2 n细胞的差异表达基因。结果　在被检测的 12 80 0个基因中 ,一些与细胞物质代谢和物质转运有关基因的表达在高致瘤性K5 6 2 n细胞与K5 6 2细胞之间有显著的变化。K5 6 2 n细胞表达上调的基因包括Dihydrodiol脱氢酶基因、肝Dihy drodiol脱氢酶基因、NAD依赖的亚甲基四氢叶酸脱氢酶 /环化脱水酶基因、人胎盘特异性ATP结合盒转运蛋白基因 ,表达下调的基因包括溶血磷脂酸酰基转移酶基因、线粒体异柠檬酸脱氢酶基因、精氨琥珀酸裂解酶基因、核糖核苷酸还原酶M1亚基基因、焦磷酸法尼酯合成酶基因、二甲基精氨酸二甲基氨基水解酶基因、细胞粘附蛋白SQM1基因等。结论　K5 6 2 n细胞的裸鼠高致瘤性等生物学特性与一系列细胞物质代谢酶和物质转运蛋白基因的表达变化有关。     

Enhancement of Tumorigenicity and Invasion Capacity of Rat Mammary Adenocarcinoma Cells by Epidermal Growth Factor and Transforming Growth Factor-β

We have studied the effects of growth factors and cytokines on the tumorigenicity and invasion capacity of tumor cells by using regressor and progressor tumor cell lines (ER-1 and ERpP, respectively) derived from an SHR rat mammary adenocarcinoma. ER-1 cells regress spontaneously whereas ERpP cells show invasive growth and high metastasis to lung and other organs in syngeneic SHR rats. When ER-1 cells were pretreated with either epidermal growth factor (EGF) or transforming growth factor-β (TGF-β) for 24 h in vitro , and intraperitoneally transplanted into SHR rats, they grew and killed the host, whereas ER-1 cells pretreated with tumor necrosis factor-α did not. Tumorigenicity and invasion capacity of ERpP cells were also enhanced by treatment with EGF and TGF-β. The ER-1 cells pretreated with EGF, once grown in vivo , had acquired irreversible tumorigenicity and invasion capacity without requiring further EGF treatment, and the enhanced malignancy was irreversible. These findings suggest that growth factors play an important role in acquisition of malignancy of tumor cells.     

HT29和HCT116结肠癌细胞无血清培养形成肿瘤干细胞球特性的差异性研究

目的比较HT29和HCT116两种结肠癌细胞系中肿瘤干细胞的差异，初步探讨结肠癌干细胞研究模型。方法以无血清培养法培养HT29和HCT116细胞，观察其在不同时间形成肿瘤干细胞球的差异，用限制性稀释法计算两者的成球率；流式细胞术分析HT29和HCT116细胞系中CD44／CD24的表达情况；裸鼠体内成瘤实验鉴定HT29细胞球与HCT116细胞球成瘤能力。结果无血清培养法发现HCT116较HT29更易形成肿瘤干细胞球且所需时间更短，即HT29在无血清培养的第7天开始形成规则的球体，而HCT116则在第5天就已形成规则的球体，HCT116成球率（11．4±1．15）％高于HT29（3．31±0．27）％，且差异有统计学意义（P〈0．05）；HT29和HCT116中CD44±／CD24±各细胞含量有显著差异，结果显示具有干细胞特性的CD44＋／CD24＋结肠癌细胞在HCT116中所占比例（60．33±5．75）％明显高于HT29（9．23±2．15）％，差异有统计学意义（t=13．939，P〈0．05）；体内成瘤实验发现HCT116细胞球在裸鼠体内的成瘤能力明显强于HT29细胞球，HCT116细胞球的成瘤速度及瘤体生长速度都较HT29细胞球快。结论与HT29相比，HCT116结肠癌细胞系更适合作为肿瘤干细胞研究的模型。     

SHZ——88大鼠乳腺癌细胞系的建立及其生物学特性观察

本研究以7,12—二甲基苯并蒽复制SD(sprague-Dawley)大鼠乳腺癌组织为材料作贴壁静置培养现已传代180余次,细胞生长稳定,定名为SHZ—88。 SHZ—88瘤细胞贴壁单层生长,光镜下为多边形,卵圆形,少数呈梭形并有树枝状突起,可见瘤巨细胞及多倍体细胞。电镜下细胞表面有微绒毛,核内及胞浆内假包涵体易见。130代细胞悬液2.2×10~4/ml,细胞接种于培养瓶内,见分裂指数第三天达高峰为59％。接种后第三天倍增时间为23小时。130代传代后第二天细胞制备染色体,100个中期分裂细胞染色体主流范围在55—65条(59％)。每只新生一周内大鼠右腋皮下接种2.5—5×10~5个细胞,致瘤率100％。~3H—TdR同位素参入法插测瘤细胞对塞替派和穿滤氨酸等药物的敏感性。     

逆转录病毒介导v-myc基因转染神经干细胞的实验研究

目的 体外通过逆转录病毒将v-myc基因转染从胎龄10～12周人工流产胚胎脑皮层分离的神经干细胞(NSCs)后，观察其生物学特性的改变。方法 分离、鉴定孕10-12周人工流产的人胚胎脑皮层来源的NSCs，并在体外培养增殖。使用构建了v-myc基因的逆转录病毒转染NSCs后，对其进行光镜及电镜观察、生长情况的测定、染色体分析以及裸鼠移植。结果 转染v-myc基因的NSCs仍然保持着未分化状态，能够自我更新以及具有多向分化潜能，并且生长速率明显加快，分裂增殖能力明显增强。然而这种细胞的染色体存在结构异常与数目异常，将其植入裸鼠皮下短期内能形成肿瘤。结论 转染v-myc基因的NSCs具有正常NSCs的基本特性，但同时也存在染色体异常与致瘤性，目前暂不适合于移植的研究及应用。     

Thymosin-α1, but not interferon-α, specifically inhibits anchorage-independent growth of hepatitis B viral transfected HepG2 cells

Background: Thymosin-α₁ is a biological response modifier that has been used clinically, alone and in combination with interferon-α for the treatment of chronic hepatitis B viral infection. Both immunomodulatory and immediate intracelluilar mechanisms have been postulated to explain the effect of these two agents on HBV-infected hepatocytes.Methods: In this study, hepatitis B transfected HepG2 hepatoblastoma cells (HepG2-Nu2), derived from 2.2.15 cells, were used as an in vitro model to determine the efficacy of thymosin-α₁ and interferon-α, individually and combined, a proliferation inhibitors of HBV-infected cells. For comparison, parental HepG2 cells and an SV40-transfected HepG2 cell line (HepG2P9T2) were also evaluated.Results: In a clonogenic soft agar assay, thymosin-α₁ inhibited the anchorage-independent growth of the HepG2-Nu2 cells by 40% compared with untreated controls, but did not inhibit parental HepG2 or HepG2P9T2 clonal growth. The response was dose dependent over concentrations spanning three log units. In comparison, 10 000 units/ml of interferon-α inhibited parental HepG2, HepG2-N4Z and HepG2P9T2 by 33%, 41% and 87%, respectively. The combination of thymosin-α₁ and interferon-α consistently inhibited HepG2-Nu2 clonal growth more effectively than either treatment alone, reaching maximum inhibition levels of 51%.Conclusions: Thymosin-α₁ specifically inhibits the tumorigenic growth of HBV-transfected HepG2 cells in contrast to the general inhibition displayed by interferon-α. This panel of cell lines may be an important resource for dissecting the mechanism by which thymosin, alone or in combination with other drugs, influences HBV-infected hepatocytes and/or HBV-associated carcinoma.