Objective To explore the mechanism of the reversal of breast cancer resistant protein-mediated multidrug resistance by 17?-estradiol. Methods Two BCRP expressing cell lines of MCF-7/MX20 and MCF-7/BCRP were established in which breast canrcer resistant protein(BCRP) was promoted by BCRP promoter and cytomegalovirus(CMV) promoter respectively.These drug resistant cell lines were cultured in medium containing 17?-estradiol.Fourty-eight hours later,cytotoxicity assay,mitoxantrone efflux assays,quantitative RT-PCR were performed to observe the reversal function of BCRP by 17?-estradiol on MCF-7/MX20 and MCF-7/BCRP respectively. Results After being treated with 17?-estradiol,the intensity of mitoxantrone in MCF-7/BCRP was weaker than that in MCF-7/MX20 and the BCRP mRNA level in MCF-7/BCRP was high than that in MCF-7/MX20.The results of these experiments revealed that 17?-estradiol could reverse the BCRP mediated multidrug resistance(MDR) in MCF-7/MX20 cells but not in MCF-7/BCRP ones.Conclusion 17?-estradiol may reverse the phenotype of BCRP through regulation of the promoter of BCRP gene but not acted as the substrate of BCRP.

Objective To explore the function of BCRP in ovary cancer and establisment of BCRP expressing ovary cancer cell line 3AO/BCRP.Methods We construct the BCRP expressing cell line 3AO/BCRP.Extract the total RNA of MCF-7 cells,clone the whole length of BCRP gene by RT-PCR and ligate the gene to pcDNA3.1(-),transfect the positive clones to 3AO cells and select positive cell clones with G418,identify the survival cells by MTT,efflux assay,western blot.Results The multidrug resistance index of 3AO/BCRP to mitoxantrone increased to 11.58 times;the efflux of 3AO/BCRP to mitoxantrone enhanced;the relative level of BCRP mRNA in 3AO/BCRP increased and western blot indicate that the 3AO/BCRP cells can express more protein than 3AO cells.Conclusion 3AO/BCRP is a reliable BCRP expressing cell model,the establishment of this cell line has laid basis for further study of the mechanism of BCRP.

Carcinosarcoma ; pathology ; Humans ; Stomach Neoplasms ; pathology

Objective To study whether transient overexpression of tumor suppressor gene PTEN could lead to growth suppression and up-regulate the sensitivity to doxorubicin of human breast cancer MCF-7 cells. Methods The eukaryotic expression plasmid pEGFP-C 1-PTEN containing whole cDNA of PTEN was constructed and transfected into MCF-7 cells by Lipofectamine 2000 in vitro. Growth inhibition of the cells was observed by phase contrast microscope and flow cytometry. The clonogenic cell survival ability was studied by clony forming assay. MCF-7 cells′ chemosensitivity to adriamycin was studied with MTT assay. Results PTEN overexpression led to morphological changes characteristic of apoptosis of MCF-7 cells. PTEN overexpression also resulted in a significant increase in G 0/G 1 cell population (14.79%) and apoptosis (10.60%) detected by flow cytometry. The clonogenic survival rate of cells transfected with PTEN was significantly decreased after doxorubicin treatment compared with control. The transfected cells were more sensitive to doxorubicin compared with the control cells ( ? 2=8.59 , P

Objctive:To investigate the immunohistochemical and morphological characteristics of the papillary thyroid microcarcinoma(PTM) ,and differential diagnosis of the related disease.Methods:The morphological characteristics of 223 patients with PTM were observed under light microscope.Seventy-four cases of PTM and 32 cases of proliferative lesion of thyroid were observed under light microscope with stains of hematoxylin and eosin and immunohistochemical staining.The antibody included CK19,MC,Galectin-3 and CD56.Results:Eighty-six cases were follicular-patterned and 31 cases nuclear features were untypical in 223 cases of PTM.The positive expression rates of CK19、MC、 Galectin-3、CD56 were 100.0%,98.6%,98.6% and 4.1% in 74 cases of PTM,and were 37.5%,12.5%,18.8%,68.8% in proliferative lesion of thyroid,respectively.Conclusion:Some cases of PTM show a follicular-patterned and the nuclear features.It is untypical compared with classical papillary thyroid carcinoma.It can be differentiated from proliferative lesion with absence of envelope,obviously various and unusually proliferated follicular cells,sclerotic stroma,neoplastic follicles among the collagen and normal follicles.The wide and intensive expression of CK19,Galectin-3,and the negative expression of CD56 are extremely useful in the diagnosis of PTM,four-marker panel with CK19,Galectin-3,MC and CD56 can improve the specificity and accuracy of the differential diagnosis of PTM.

Objective To explore if grape seed polyphenols (GSP) reverses human breast cancer multidrug resistance. MethodsIn this study,adriamycin-resistant human breast carcinoma cells ( MCF-7/ADR ) and its parental cells (MCF-7) were used to determine the effect of GSP. MTT assay was adopted to evaluate the cytotoxity. Western blot and Northern blot were performed to observe the expression of MDR1 in MCF-7/ADR. Adriamycin accumulation was measured by flow cytometry (FCM). ResultsGSP ( 1.2 mg/L ,2.4 mg/L) inhibited the expression of P-gp to 80.83%( t =5.58,P

Objective To investigate the relationship of c erbB2 with endocrine therapy and prognosis, to investigate the rapid and effective method to detect c erbB2 alteration in breast carcinoma(BC).Metheds Semi quantitative PCR was used to detect the amplification of c erbB2, and immunohistochemistry was used to detect the expression of protein of c erbB2. 58 cases of BC were followed up .Results There was significant relationship between c erbB2 protein overexpression and gene amplification(P

Objective To construct the plasmid containing short hairpin RNA (shRNA) of GCS in order to suppress the expression of GCS and to reverse the multidrug resistance in drug-resistant breast cancer cells. Methods Two reverse repeated motifs of sequence targeting GCS with 6 bp spacer were designed and synthesized in vitro,then they were inserted into the plasmid pSUPER. The recombinant plasmids were transfected into human breast cancer cells. GCS expression was detected by Western blot and immunocytochemistry. caspase-3 expression and its activity were assessed using Western blot and colorimetry,flow cytometry was performed to analyze the ratio of apoptosis. Results MTT method was used to evaluate the 50% inhibition concentration. Enzyme digestion analysis and DNA sequencing confirmed that the recombinant plasmids were successfully constructed. GCS protein content decreased 80%,82% respectively after transfection with recombinant plasmids. The positive rate of GCS expression reduced to 18.1%,16.7% respectively. caspase-3 expression and its activity were significantly higherand the apoptosis of cells increased dramatically. The drug resistance of breast cancer cells to antineoplastic drugs declined significantly. Conclusion shRNA can suppress GCS expression in human drug-resistant breast cancer cells effectively and restore the sensitivity to several antineoplastic drugs.

Objective　To investigate the relationship between multidrug resistance(MDR) and chemotherapy and the possibility of P-gp as a clinical prognostic indicator. Methods　P-gp, MDR1 gene product, was detected in 66 cases of relapsed lung cancer patients after chemotherapy and 131 lung cancer patients with no prior chemotherapy by immunohistochemistry. Results　The expressive level of P-gp in relapsed group after chemotherapy was much higher than that of non-chemotherapy group (P＜0.05). A significant difference of P-gp expression existed between before and after chemotherapy for squamous cell carcinoma and SCLC (P＜0.05), but not for adenocarcinoma. In non-chemotherapy group, lung cancer tissues with different histological types had different P-gp positive rates, which were adenocarcinoma, squamous cell carcinoma and SCLC in sequence from high to low (P＜0.05). In relapsed group after chemotherapy, there was no significant difference among the three types of lung cancer (P＞0.05). P-gp positive group had a significantly lower 3-year survival rate than negative group (P＜0.05). Conclusion　Chemotherapy may increase the incident rate of MDR in lung cancer. Adenocarcinoma is mainly primary MDR while SCLC and squamous cell carcinoma are mainly secondary to chemotherapy. P-gp expressive level can be used as a common clinical indicator for prognosis and chemotherapy in the patients with lung cancer.