SPZ1 mediates chemoresistance of renal cell carcinoma through EGFR- dependent pathway

• Main Authors: Chia-Lo Ho, 何佳珞
• Other Authors: Yi-Fu Chen
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/86327410402588140816

碩士 === 高雄醫學大學 === 生物科技學系碩士班 === 102 === Transcription factor SPZ1 (Spermatogenic leucine zipper 1) was shown to act as a proto- oncogene in previous studies. In this study, comparison of cisplatin IC50 values of two renal cell carcinoma cell lines, ACHN and 786O, with different SPZ1 protein levels, suggests that ACHN, the one with higher expression of SPZ1, has higher IC50. With treatment of chemotherapy drug cisplatin, SPZ1 protein and mRNA were induced in a time- and dose- dependent way, and translocation of SPZ1 from the cytosol to the nucleus was also observed. In addition, following SPZ1 induction, EGFR and its downstream signaling pathways, including PI3K/AKT, ERK1/2, STAT3, and some related anti- apoptotic factors such as BCL2 and survivin, were also induced. When EGFR was knocked down by siRNA, the induction of P-ERK and P-STAT3 was not as much as the induction of scramble control with treatment of cisplatin. Examination of SPZ1 knockdown stable clone (ACHN- SPZ1i) revealed that the expression of EGFR and the downstream molecule P-ERK were decreased, and no induction of EGFR and BCL2 was seen when treated with cisplatin in a time- dependent way. EGFR promoter activity was activated in ACHN- Vector with treatment of cisplatin; in contrast to ACHN- Vector, activity was not activated in ACHN- SPZ1i. CHIP assay (Chromosome Immunoprecipitation) result suggested SPZ1 regulated EGFR promoter by binding on it. Eastablishing target-therapy drug Sorafenib-resistant cell lines ACHN-1.0 μM Sorafenib and ACHN-2.0 μM Sorafenib, it showed that ACHN-1.0 μM Sorafenib grew faster than parental ACHN in nude mice and had higher expression in IHC (Immunohistochemistry) results. Overall, SPZ1 might mediate chemoresistance of renal cell carcinoma through EGFR- dependent pathway.