RLIP (Ral-interacting protein)-76/RalBP11 (Ral-binding protein-1), a multifunctional protein and stress-inducible non-ABC transporter, have been proven to serve as a critical role in cancer development and progression; however, little is known about the pathological role of RLIP76 in breast cancer patients.
Here, we investigated the effect of the ABCG2 substrate topotecan on the MCF-7 breast cancer cell line and analyzed CD24, CD44, EpCAM, and HER2 expression by flow cytometry.
Our results support the hypothesis that the presence of ABCG2(+) cells in breast carcinomas is a marker of resistance to chemotherapy, and based on in vitro assays and the genetic profile, we show, for the first time, that ABCG2 protein can be used as an independent marker for TIC identification in breast cancer.
These results suggested that the ABCG2 polymorphisms might be a candidate pharmacogenomic factor to assess susceptibility and prognosis for breast carcinoma patients.
Inhibition or upregulation of HIF-1α affects breast cancer cell expression of BCRP; AI responsiveness; and expression of cancer stem cell characteristics, partially through BCRP.
Transcriptional targeting of human liver carboxylesterase (hCE1m6) and simultaneous expression of anti-BCRP shRNA enhances sensitivity of breast cancer cells to CPT-11.
Among the membrane efflux transporters of MTX, the human breast cancer resistant protein is the second member of the G subfamily of ATP-binding cassette (ABC) efflux pump (ABCG2).
We have shown, for the first time, that ABCC1, ABCC11, and ABCG2 are highly expressed in aggressive breast cancer subtypes, and that tumor ABCC11 expression is associated with poor prognosis.
These results suggest that PROG reverses BCRP-mediated MDR by down-regulating BCRP expression in breast cancer cells by affecting transcription from the PRE-containing BCRP promoter.
Fulvestrant resistance was associated with repression of GPER and the overexpression of CDK6, whereas ERBB2, ABCG2, ER and ER-related genes (GREB1, RERG) or genes expressed in resistant breast cancer (BCAR1, BCAR3) did not contribute to resistance.
Microarray analysis was performed to determine the differential expression patterns of miRNAs that target BCRP between the MX-resistant breast cancer cell line MCF-7/MX and its parental MX-sensitive cell line MCF-7.
Our results demonstrated that active PR inactived BCRP expression via progesterone-PR complexes binding to PRE in BCRP promoter in breast cancer cells.
Using the MTT assay, we found that zafirlukast enhanced the cytotoxicity of several anticancer drugs that are substrates of breast cancer resistance proteins (BCRP/ABCG2), including mitoxantrone and SN-38.
The delivery concept of multiple siRNAs against ABC transporter genes is highly promising for preclinical and clinical investigation in reversing the multidrug resistance phenotype of breast cancer.
In this study, we aimed to evaluate any positive correlation between COX-2 and ABCG2 gene expression using the COX-2 inducer 12-O-tetradecanoylphorbol-13-acetate (TPA) in human breast cancer cell lines.
In in vitro selected doxorubicin resistant MCF-7 cells (MCF-7/doxoR) overexpressing the multidrug resistance (MDR) related ABCG2 transporter, we observed a significant HuR downregulation that was paralleled by a corresponding downregulation of HuR targets and by loss of rottlerin toxicity.
Adenovirus adenine nucleotide translocator-2 shRNA effectively induces apoptosis and enhances chemosensitivity by the down-regulation of ABCG2 in breast cancer stem-like cells.
For example, the expression of breast cancer-resistant protein (BCRP/ABCG2) has been shown to confer acquired resistance of wild-type EGFR (wtEGFR)-expressing cancer cells to gefitinib.