蜂胶体外诱导人喉癌细胞Hep-2凋亡的实验研究

目的:探讨蜂胶对喉癌细胞珠Hep-2凋亡的影响及作用机制。方法:应用MTT、透射电镜、原位末端标记法观察药物对细胞的抑制率及凋亡形态、凋亡率变化。结果:MTT测得细胞抑制率随时间、剂量而增大,透射电镜下见到凋亡细胞及凋亡小体形成,原位末端标记检测出细胞凋亡率亦有时间、剂量依赖性。结论:蜂胶能够抑制喉癌细胞生长,其抑制作用是通过诱导喉癌细胞凋亡而起作用的。

Relation between the Expression of K-ras in Hep-2 Cells and Development of Laryngeal Carcinoma~*

Objective： To investigate the expression of K-ras in human laryngeal squamous cell carcinoma cell lines （Hep-2） and its significance for establishing a solid foundation for further study of the relationship between human laryngeal squamous cell carcinoma and K-ras gene point mutations. Methods： The expression of K-ras in human laryngeal squamous cell carcinoma cell lines （Hep-2） and human pancreatic carcinoma cell lines （MIAPaCa-2） was detected by using RT-PCR. Results： The expression of K-ras mRNA in Hep-2 and MIAPaCa-2 was strong and positive. Conclusion： The expression of K-ras mRNA in human laryngeal squamous cell carcinoma cell lines （Hep-2） is positive. Development of laryngeal carcinoma might be related to the activation of K-ras gene point mutation.

The impact on secreted VEGF of Hep-2 human laryngeal cancer cell induced by Rg3

Objective：The aim of this study was to investigate the af ecting of Rg3 to secreted VEGF of human laryngeal carcinoma Hep-2 cells and its mechanism of inhibition to tumor angiogenesis. Methods：Cultured human laryngeal cancer cellline Hep-2 and human vascular endothelial cells in vitro, cells got into the period of exponential phase of growth, was diviced into 3 groups：group I （control group）, group II （DDP group）, group III （Rg3 group）. Added to the Hep-2 cells Rg3 and DDP, made Rg3 final concentration was 300μg/mL, and DDP was 3μg/mL. 48 h later, specimens from sample to be done immunocytochemistry, and the protein of VEGF in Hep-2 cells to be detected. Col ecting Hep-2 cells supernatant, some was used to measure the protein level of VEGF in Hep-2 cells supernatant by ELISA. Some was used to culture HVEC. 24 h later, cellgrowth inhibition rate of human vascular endothelial was determined by MTT. Results：The protein level of VEGF was evi-dently higher in group I compared to group II and group III, it was not only in Hep-2 cells, but also in supernatant of Hep-2 cells. There was no significantly dif erent between group II and group III. MTT results showed that, the human vascular endothelial cellgrowth inhibition rate of group I was significantly lower than that of group II and group III （P〈0.05）. At the same time the HVEC growth inhibition rate of group II was significantly lower than that of group III （P〈0.05）. Conclusion：The inhibition to tumor angiogenesis of Rg3 is stronger than traditional chemotherapy drug cisplatin. It worke by reducing the biological ef ects of secreted VEGF, But the ef ecting worke by reducing the activity of secreted VEGF itself or af ecting endothelial function of VEGF receptor or some other ways to be further studied.

Induction of apoptosis and inhibition of proliferation in Hep-2 by antisense survivin RNA in vitro

Objective.. To study induction of apoptosis and inhibition of proliferation in Hep-2 by antisense survivin RNA. Methods： Antisense survivin RNA expression vector was constructed and then was transfected to human laryngeal carcinoma cell line Hep-2 by lipofectamine. HpEGFP/survivin cells （transfected with the combinant of antisense survivin RNA） were obstained by using G418. The levels of survivin protein before and after transfection were determined by Western-blot. Proliferation activity was measured by MTT assay. The experiment of colony formation in soft agar was carried out for assessing ability of proliferation of Hep-2 cell. Apoptosis was assessed by flow cytometry and acrdine orange（AO）. Results： After antisense survivin RNA plasmids were transfected, the level of survivin protein was inhibited in Hep-2. Compared with control, proliferation of HpEGFP/survivin cells were suppressed significantly. The experiment of colony formation in soft agar showed the ability of colony formation decreased in HpEGFP/survivin cells compared to control （P〈0.05）. Apoptosis rate increased about 1.81-folds compared with control. Conclusion.. The antisense survivin RNA can partly inhibit the level of surviivin protein expression in Hep-2 and can induce apoptosis and inhibit the proliferation of Hep-2 by down-regulating the expression of endogenous survivin in vitro.

Department of Etiology and Department of Pharmacology

In order to understand the role of transmembrane signal transduction of host cells in the early steps of infection,the adherence of E. coli to HEp 2 cells and the change of activity of phospholipase C γ (PLC γ) induced by the adherence were investigated.The adherence of enteropathogenic E.coli (EPEC), strain E.7, induced a significant increase of inositol triphosphat (IP 3) level in HEp 2 cells. The adherence of the bacteria and the increase of IP 3 was kinetically correlated. Whereas the increase of IP 3 level induced by the adherence of the control strain EPEC (H511), a non piliated strain, was much meager than that by E7, a piliated strain. The results highlighted an important role of transmembrane signals like IP 3 in the pathogenesis of EPEC.

In Vitro Study on the Effect of Bee Venom on Some Cell Lines and Lumpy Skin Disease Virus

Bee venom （BV） was used from long time ago in the medical field as treatment of chronic joint affections. In the recent decades, the screening process of new sources of antimicrobials discovers its high advantageous characteristics for combating various types of microbes, as well as trials to discover its anti-cancer medicinal fields. Lumpy skin disease virus （LSDV） causes disease in cattle of economic importance, and this work aimed to find treatment as well as alternative inactivant for LSDV. The use of bee venom as antiviral was experimented in this work and exhibited satisfied inhibitory effects on LSDV, meanwhile, the antigenic properties was still intact. The viability of virus was tested in tissue culture cells lines and in embryonated chicken eggs. According to doses and time of exposure, the cell lines of Hep-2 （human larynx carcinoma） and MCF7 （breast carcinoma cell line） were treated with different concentrations of BV and examined after 24 h post-inoculation. The Hep-2 and MCF7 cell lines were treated with various concentrations of BV in descending doses as follow： 25, 20, 15, 10, 5 and 0.5 ug/mL of BV. Then bee venom pathological effects on Hep-2 cells and MCF7 cells were observed, such as apoptosis, retarded growths and cytolysis. The results indicate the possibilities of using bee venom as anti-neoplastic and antiviral.