Growth Inhibition of Breast Cancer in Rat by AAV Mediated Angiostatin Gene

Objective： To observe growth inhibition effect of adeno-associated viral vectors （AAV） mediated angiostatin （ANG） gene on implanted breast cancer in rat and its mechanism. Methods： Gene transfer technique was used to transfer AAV-ANG to the tumor. Growth curves were drawn to observe the growth of breast cancer implanted in rat, and immunohistochemical method was used to detect the effects of angiostatin on microvesel density （MVD） of breast cancer implanted in rat. Results： Angiostatin inhibited the growth of breast cancer implanted in rat and decreased the microvessel density of tumor. Conclusion： Expression of an angiostatin transgene can suppress the growth of breast cancer implanted in rat through the inhibition of the growth of microvessels, surggesting that angiostatin gene transfer technique may be effective against breast cancer.

COMBINED DETECTION OF CYCLIN D1,P27 AND DNA CONTENT IN ESOPHAGEAL CANCER

Objective： To investigate the expressions of cyclin D1 and p27 and DNA content in esophageal cancer and adjacent normal tissues, and to discuss the relationship between them. Methods： The cyclinD1 and p27 were detected by immunohistochernical staining; DNA content was measured by flow cytometry. Results： The positive expression rates of cyclinD1 and p27 in cancer were 45.8% and 33.3% respectively, the DNA content in the positive group of cyclinD1 was higher than that in the negative group of cyclinDl（1.54±0.21 versus 1.08i-0.43, P〈0.05）, while the DNA content and SPF （S-phase fraction） in the positive group of p27 were lower than those in the negative group （1.10±0.19 and 5.56%±5.18% versus 1.66±0.28 and 19.78%±6.12%, P〈0.05）. Conclusion： The data show that the expression of cyclinD1 and p27 are related to the ontogenesis and progression of esophageal cancer. The combined detection of cyclinD1, p27 and DNA content may be indicators of diagnosis and assessment of esophageal cancer.

Effects of Various Factors on Proliferation Capacity and Cytotoxicity of Induced CIK of Patients with Tumor In Vitro

Objective： To evaluate effects of different factors on proliferation capacity and cytotoxicity of induced cytokine induced killer （CIK） cells in vitro, so as to provide experimental basis for cell therapy of CIK in tumor. Methods： Cytometry and MTT assay were used in detecting proliferation capacity and cytotoxicity of CIK. Results： The proliferation capacity and cytotoxicity of CIK in vitro were stronger in the group of low age and serum free medium than in the group of advanced age or serum medium. And the proliferation of CIK in vitro increased with time during a certain period of incubation. Furthermore, CIK had equal cytotoxicity to various tumor cells. Conclusion： Various factors might influence the proliferation capacity and cytotoxicity of CIK of tumor patients in vitro.

Apoptosis of Human Pancreatic Carcinoma Cells Induced By All-Trans Retinoic Acid and Interferon

Objective： To investigate the apoptosis of human pancreatic carcinoma PC3 cells induced by the combination of all-trans retinoic acid （ATRA） with interferon alpha （IFN-α）. Methods： PC3 cells were treated with ATRA and IFN-α. The inhibitory rate of PC3 cell proliferation was detected using MTT method. Cellular apoptosis was determined with flow cytometry. The percentage of PC3 cell apoptosis was assayed using TUNEL methods. Results： ATRA and IFN-α could inhibit cellular proliferation and induces cellular apoptosis of PC3 cells. The inhibitory effect was stronger when the ATRA and IFN-α were combined as a therapy. Conclusion： ATRA inhibits the proliferation of PC3 cells and induce the apoptosis of PC3 cells. The combination of IFN-α with ATRA may enhance these effects on PC3 cells.

Bufalin Induces Programmed Necroptosis in Triple-Negative Breast Cancer Drug-Resistant Cell Lines through RIP1/ROS-Mediated Pathway

Objective: To explore the effect and mechanism of action of bufalin in triple-negative breast cancer(TNBC) drug-resistant cell lines. Methods: The normal human mammary epithelial cell line, TNBC cell line, TNBC adriamycin-resistant cell line, and TNBC docetaxel-resistant cell line were treated with different doses of bufalin(0–1,000 nmol/L) at different time points(0–72 h). Propidium iodide staining, AV-FITC/PI double staining, Hoechst 33342/PI double staining and transmission electron microscopy(TEM) were used to evaluate the death patterns of the cell lines. Results: Bufalin killed the TNBC cell line and its drug-resistant cell lines in a dose/time-dependent manner(all P<0.01). After treatment with bufalin for 24 h, the adriamycinresistant cell line showed a co-existing pattern of necroptosis and apoptosis. However, at 48 h, necroptosis was the main manifestation. After treatment with bufalin, the expressions of tumor necrosis factor α, phospho-tumor necrosis factor receptor 1, phospho-receptor interacting protein 1 and c-caspase 3 increased(all P<0.01), the killing effect of bufalin could be mostly inhibited by NEC-1, and by z-VAD-fmk(both P <0.01). Besides, the intracellular reactive oxygen species(ROS) levels increased considerably(P<0.01), the antioxidant N-acetyl cysteine or Nec-1 could inhibit the increase of ROS level and the killing effect of bufalin(all P<0.01). The adriamycin-resistant cell line exhibited necroptosis characteristic after 48 h of bufalin treatment under TEM. Conclusions: Bufalin could induce necroptosis through RIP1/ROS-mediated pathway to kill the drug-resistant TNBC cell lines. This finding provides critical experimental data and theoretical basis for the clinical application of bufalin to overcome the difficulties in the treatment of TNBC.