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Objective To explore the influence of alpha-fetoprotein (AFP) on the expression of drug-resistance gene MDR1 and chemotherapeutic sensitivity in hepatocellular carcinoma (HCC) cells.Methods A HCC cell line SMMC-7721/AFP, which was stably transfected with AFP gene, was established.mRNA and protein expressions of AFP and MDR1 were detected by real-time PCR and Western Blot,respectively.The sensitivity of SMMC-7721/AFP and SMMC-7721/EGFP cells with or without MDR1 silencing by siRNA to doxorubicin was tested by MTT assay.Immunohistochemistry was used to detect the expression of MDR1 genes-coded protein Pgp in 60 cases of HCC tissues, and the relationship between Pgp expression and serum AFP levels was analyzed.Results AFP mRNA and protein could be detected in SMMC-7721/AFP cells, but not in control cells, indicating that the AFP stably transfected cell line was successfully established.MDR1 mRNA and protein levels were higher in SMMC-7721/AFP cells than those in SMMC-7721/EGFP cells.MDR1 mRNA level in SMMC-7721/AFP cells was (52.7 ± 1.5) times as high as that in SMMC-7721/EGFP cells (P ＜ 0.05).The resistance to doxorubicin was increased by (12.8 ± 1.1) times after AFP transfection (P ＜ 0.05).The chemosensitivity to doxorubicin was increased after the expression of MDR1 was knocked down by siRNA.The expression of Pgp in HCC tissues was positively correlated with the serum AFP levels.Conclusion AFP could induce drug-resistance to doxorubicin in HCC cells by increasing the expression of MDR1.
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Objective To investigate the modulation for multidrug resistance cell line K562/A02 us- ing a specific siRNA against mdrl,GST?.Methods siRNA were synthesized targeting the coding region se- quences of mdrl(79～99 nt)and GST?(308～327nt)respectively,and cloned to plasmid pSilence2.1-U6.The cloned products pSilenee-mdr1 and pSilence-GST? were transfected into K562/A02 cells.Expression of mdr1 and GST? mRNA were assayed by SYBR Green Ⅰ real-time PCR.The apoptosis of cell line K562/A02 was examined by Flow cytometry,50% inhibition concentration(IC_(50))of doxorubicin on K562/A02 cell was deter- mined by MTT method.Results The siRNA expression vector against mdr1,GST? mRNA was constructed successfully.After transfected with pSilenee-mdr1,the expression of mdr1 mRNA in K562/A02 in was re- duced 71.5 % compared to the mock transfeetion,from(2.8?1.65)?10~8 copy/?g RNA to(3.9?2.37)?10~7 copy/?g RNA(P
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Objective To explore the relationship between mdr1 gene expression of hepatocellular carcinoma (HCC) and pathological characteristics,chemotherapy and prognosis. Methods The mdr1 gene expression of HCC in 56 patients with the methods of immunohistochemistry was studied. The results were analysed with the pathological data by statistic methods. Results The positive expression of mdr1 gene in cancer tissues and pericancerous tissues of HCC were 30/56(53.6%) and 19/56 (33.9%) respectively. The difference was statistically significant (? 2=4.39, P
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Objective:To study the reversal effect of tamoxifen(TAM)on the expression of mdr1 in human pancreatic cancer cell lines.Methods:The inhibtion effect of TAM on pancreatic cancer cell line SW1999、Capan-Ⅱ and mammary cancer cell line T47D were studied;The influence of TAM on mdr1 protein/mRNA expression in SW1999、Capan-Ⅱ and T47D were studied using the method of flow cytometer and RT-PCR.Results:The high dose TAM could inhibit Capan-Ⅱ cell line.TAM could reverse the expression of mdr1 protein and mRNA in Capan-Ⅱ cell line and T47D cell line. Conclusion:The high dose TAM could inhibit Capan-Ⅱ cell line,maybe related with reduction of the expression of mdr1 protein and mRNA.