Preliminary Study of Apoptotic Inhibition and Its Molecular Mechanism of Dexamethasone on Cisplatin-induced Human Lung Adenocarcinoma Cell Line SPCА/I

CAO Fei, ZHANG Zhi-hui, WU Ping. et al

Abstract

To study the apoptotic inhibition and its molecular mechanism of dexamethasone (Dex) on cisplatin (CDDP)-induced human lung adenocarcinoma cells. Methods The human lung adenocarcinoma cell line, SPCA/Ⅰ, was pre-cultured in vitro for 24 hours with Dex in different concentration and then different concentration of CDDP was added. The cells were cultured for another 48 hours. The survival rate of the cells was determined by MTT colorimetry. The appototic rate of SPCA/Ⅰ cells measured by flow cytometer. Using 1 μmol/L Dex to stimulate the SPCA/Ⅰ cells RNAs of the cells at different time points (1 h, 2 h, 4 h, 6 h, 12 h) were extractedrespectively. Semi-quantitative RT-PCR technology was used to detect the expression of the serum and glucocorticoid-induced kinase (SGK-1) and mitogen-activated protein kinase phosphatase-1(MKP-1) in SPCA/Ⅰ cells. Simultaneously the glucocorticoid receptor (GR) of the SPCA/Ⅰ cell line cells were measured by using biotin-labeled anti-glucocorticoid receptor antibody with immunohistochemistry assay. Results SPCA/Ⅰ cells showed resistance to CDDP-induced apoptosis while pre-cultured with Dex and the resistance intensity was Dex concentration-dependent. After Dex stimulating the SPCA/Ⅰ cells, SGK-1 expressed increased and reached the peak at 12 h. But the expression of MKP-1 was not detected. Immunohistochemistry results showed that up-regulated GR in SPCA/Ⅰ cells after stimulation with Dex. The number of intracellular GR was significantly higher than that of control group. Conclusion The experimental results in vitro demonstrated that Dex inhibits apoptosis on CDDP-induced human lung adenocarcinoma cell line, SPCA/Ⅰ. This anti-apoptosis effect might due to Dex increasing the expression of SGK-1, an anti-apoptotic protein, in its downstream signal pathway through the increasement of intracellular GR of SPCA/Ⅰ cells.

 

Keywords: Dexamethasone, Lung cancer, Cisplatin, Apoptosis 

 

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References


Zhang С. Marme A, Wenger T, et al. Glucocorticoid-mediated inhibition of chemotherapy in ovarian carcinomas. Int J Oncol. 2006;28(2):551-558.

Zhang С. Beckermann B, Kallifatidis G. et al. Corticosteroids induce chemotherapy resistance in the majority of tumour cells from bone, brain, breast, cervix, melanoma and neuroblastoma. Int J Oncol.2006 ;29(5): 1295-1301.

Wu W. Chaudhuri S. Brickley DR. Microarray analysis reveals glucocorticoid-regulated survival genes that are associated with inhibition of apoptosis in breast epithelial cells. Cancer Res. 2004;64(5):1757-1764.

Zhou J. Cidlowski JA. The human glucocorticoid receptor:one gene, multiple proteins and diverse responses. Steroids, 2005; 70(5-7):407-417.

Dharminder C, Pramod P. Atsushi O, et al. Dexamethasone induces apoptosis of multiple myeloma cells in a JNK/SAP kinase independent mechanism. Oncogene. 1997; 7 ( 15) : 837- 843.

Li Z. Chen Y. Cao D. et al. Glucocorticoid up-regulates transforming growth factor-beta ( TGF-beta) type Ц receptor and enhances TGF-beta signaling in human prostate cancer PC- 3 cells. Endocrinology, 2006; 147< 11); 5259-5267.

Yano A, Fujii Y, Iwai A, et al. Glucocorticoids suppress tumor angiogenesis and in vivo growth of prostate cancer cells. Clin Cancer Res, 2006; 12(10): 3003-3009.

Yemelyanov A, Czwomog J, Gera L, et al. Novel steroid receptor phyto-modulator compound a inhibits growth and survival of prostate cancer cells. Cancer Res,2008; 68 ( 12): 4763-4773.

Melhem A. Yamada SD. Fleming GF.fV al. Adminis tration of glucorticoids to ovarian cancer patients is associated with expression of the anti-apoptotic genes SGK1 and MKP1/ DUSP1 in ovarian tissues. Clin Cancer Res,2009; 15(9);3196- 3204.

Duma D, Jewell CM. Cidlowski JA. Multiple glucocorticoid receptor isoforms and mechanisms of post-translational modification. J Steroid Biochem Mol Biol, 2006 ; 102 ( 1-5) : 11- 21.

Schmidt S. Rainer J. Ploner C, et al. Glucocorticoid-induced apoptosis and glucocorticoid resistance: molecular mechanisms and clinical relevance. Cell Death Differ. 2004 ; 11 ( Suppl 1):S45-S55.

Herr I. Gassier N. Friess H. et al. Regulation of differential pro- and anti-apoptotic signaling by glucocorticoids. Apoptosis. 2007;12(2):271-291.

Brunet A, Park J. Tran H, et al. Greenberg ME protein kinase SGK mediates survival signals by phosphorylating the forkhead transcription factor FKHRL1 (FOXPO3a). Mol Cell Biol. 2001; 21(3):952-965.

Burgering BM, Medema RH. Decisions on life and death; FOXO forkhead transcription factors are in command when PKB/Akt is off duty. J Leukoc Biol.2003;73(6);689-701.

Song G, Ouyang G, Bao S. The activation of Akt/PKB signaling pathway and cell survival. J Cell Mol Med. 2005; 9 (1); 59-71.


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