Rosiglitazone Inhibition Lymph Node Metastasis Of Non-small Cell Lung Cancer And Induce The Apoptosis Of Bronchogenic Carcinoma By Down-regulating The Expression Of IGF-1

With the deeper understanding of PPARs gene, there was an increasing interest in the roles of PPARγ's in cancer. Several studies have indicated that PPARγ's agonist could induce apoptosis of tumor cells in breast cancer colorectal carcinoma,gastric cancer,Prostate Cancer, The metastasis of Lymph node in non-small cell lung cancer is an important factor in acromegalic poor prognosis such as recurrence and death, In which the corresponding ligands of PPARγcan induce physical terminal differentiation of a variety of tumors, inhibit tumor cell proliferation, in clinical treatments of liposarcoma and prostate cancer, PPARγligands have shown good anti-tumor effect. With the discovery of the lymphatic endothelium-specific markers and lymphatic growth factor, The molecular mechanisms of lymphangiogenesis by NSCLC-induced and with lymphangiogenesis as a target of anti-tumor metastasis has become a hot spot in the current study, The inhibition of tumor lymphangiogenesis may be provide new ideas for the controlling of non-small cell lung cancer lymph node metastasis. In this test, we use the cancer cells A549, who have been improved to be with expression of PPARγ. To study the effects of rosiglitazone on inhibiting lymph node metastasis and the induction of apoptosis of non-small cell lung cancer by down-regulating the expression of IGF-1. We observe the changes of these cells to investigate the roles of PPARγin non-small cell lung cancer and to find a better way to cure this disease.Insulin-like growth factor (Insulin-like growth factor, IGF) in particular, IGF1 not only promote the infinite proliferation of non-small cell lung cancer, but also make a close relationship with lymph node metastasis, IGF-1 can be used as biological behavior of non-small cell lung cancer, especially can be the indicators to judge the transfer of lymph node. Rosiglitazone is a peroxisome proliferator-activated receptorγ(PPARγ) agonists, which can induce apoptosis in non-small cell lung cancer and inhibit non-small cell lung cancer cell invasion and metastasis. Moreover, rosiglitazone has been shown to inhibit breast cancer cells through the PI3K/Akt channels in IGF-I expression. Accordingly, we speculated that rosiglitazone may be by inhibiting IGF-I to inhibit lung cancer cells in lymph node metastasis. Therefore, this experiment observed the role of rosiglitazone on A549 cells with the expression of IGF-1 to study and to explore mechanism of rosiglitazone inhibit non-small cell lung cancer metastasis and Numerical increasing.【Objective】To rosiglitazone on inhibiting lymph node metastasis and the induction study the effects of of apoptosis of non-small cell lung cancer by down-regulating the expression of IGF-1.【Methods】1. The culture of A549 cells and the treatment of rosiglitazone on A549 cells;2. Hoechst3222 staining was adopted to detect apoptosis of the A549 cell treated by rosiglitazone with different concentration. At 48 hours after transfection, Hoechst3222 staining was performed, fluorescence microscope was used to observing changes in nuclei. Choose five high-power vision, count the number of apoptotic nuclei, and compare with blank control group cells;3. TEM was used to observe the ultrastructural changes of cell;4. Real time PCR was used to detect the local expression of VEGF-C in lung cancer A549 cells dealed by rosiglitazone;5. Immunofluorescence technique was used to detect the local expression of VEGF-C in lung cancer A549 cells dealed by rosiglitazone.And make the bar graph of the cells;6. Western blot was used to do the semi- quantitative analysis of the IGF-1 expression. Westen blotting detect expression of PPARγprotein Cells were harvested at 24 hours after transfection for SDS-PAGE electrophoresis. AlphaEaseFC software analysis system was used to analysis of gray value of the strip;7. Data was described in the mode of x±s.Apoptosis ratio was analyzed by the way of chi square test analosis, and the expression of VEGF-C and IGFI-1 was analyed by the way of ANOVA.【Results】1. Apoptosis of A549 cells induced by rosiglitazone is a dose-dependent. Apoptosis ratio induced by Rosiglitazone with different concentration of 0,10,20,30μM were 0.012±0.033.0.105±0.177,0.388±0.201,0.437±0.189. After transfection, Early signs of apoptosis took place in small part of nuclear in interfering group. Nuclear membrane shrinked and turned into a wavy; After 48 hours, a marked increase of apoptotic cells appeared. Chromatin was concentrated into large granular and was of margination. Apoptotic bodies had appeared in a few cells or the entire nucleus turned into dense concentration or apoptotic bodies. TEM was used to observe the ultrastructural changes of cell.2. Rosiglitazone down-regulated local expression of VEGF-C in a dose-dependent manner. After 48h treated by Rosiglitazone, fluorescence was weaken compared with blank control group, while there was no specific fluorescence in the negative control group.3. The expression of IGF-1 were 0.761±0.006,0.410±0.0142,0.361355±0.006,0.209±0.018 after treated by different concentration of Rosiglitazone treating 24h later.【Conclusions】IGF-1 pathway may play a key role in the mechanism in which Rosiglitazone significantly inhibit metastasis and induce apoptosis of non-small cell lung cancer cells. IGF-1 may play a key role in inducing apoptosis and inhibiting lymph node metastasis.