A Critical Dose of Doxorubicin Is Required to Alter the Gene Expression Profiles in MCF-7 Cells Acquiring Multidrug Resistance

Abstract

Cellular mechanisms of multidrug resistance (MDR) are related to ABC transporters, apoptosis, antioxidation, drug metabolism, DNA repair and cell proliferation. It remains unclear whether the process of resistance development is programmable. We aimed to study gene expression profiling circumstances in MCF-7 during MDR development. Eleven MCF-7 sublines with incremental doxorubicin resistance were established as a valued tool to study resistance progression. MDR marker P-gp was overexpressed only in cells termed MCF-7/ADR-1024 under the selection dose approaching 1024 nM. MCF-7/ADR-1024 and authentic MCF-7/ADR shared common features in cell morphology and DNA ploidy status. MCF-7/ADR-1024 and authentic MCF-7/ADR down regulated repair genes BRCA1/2 and wild type p53, apoptosis-related gene Bcl-2 and epithelial-mesenchymal transition (EMT) epithelial marker gene E-cadherin. While detoxifying enzymes glutathione-S transferase-π and protein kinase C-α were up-regulated. The genes involving in EMT mesenchymal formation were also overexpressed, including N-cadherin, vimentin and the E-cadherin transcription reppressors Slug, Twist and ZEB1/2. PI3K/AKT inhibitor wortmannin suppressed expression of Slug, Twist and mdr1. Mutant p53 with a deletion at codons 127-133 markedly appeared in MCF-7/ADR-1024 and authentic MCF-7/ADR as well. In addition, MCF-7/ADR-1024 cells exerted CSC-like cell surface marker CD44 high/CD24 low and form mammospheres. Overall, results suggest that resistance marker P-gp arises owing to turn on/off or mutation of the genes involved in DNA repair, apoptosis, detoxifying enzymes, EMT and ABC transporters at a turning point (1.024 μM doxorubicin challenge). Behind this point, no obvious alterations were found in most tested genes. Selection for CSC-like cells under this dose may importantly attribute to propagation of the population presenting invasive properties and drug resistance. We thereby suggest two models in the induction of drug resistance. Model 1: Selection for CSC-like cells. Model 2: Mutations for gain-of resistance. Either model 1 or model 2 requires doxorubicin dose approaching 1 μM to alter gene regulation.

Timosaponin A-III reverses multi-drug resistance in human chronic myelogenous leukemia K562/ADM cells via downregulation of MDR1 and MRP1 expression by inhibiting PI3K/Akt signaling pathway

“…The phosphoinositide 3-kinase/serine-threonine kinase (PI3K/Akt) signaling pathway is a well-known fundamental intracellular signaling transduction pathway involved in multiple biological processes both in normal and cancer cells, including gene transcription and translation, cell growth, proliferation and survival, cell metabolism, cell cycle progression, apoptosis and autophagy (8)(9)(10). Besides, there is an increasing amount of preclinical data supporting that the PI3K/Akt signaling pathway is also involved in the drug resistance of different types of human malignant cells, including CML (2,4,5,(12)(13)(14)(15). A previous study demonstrated that the resistant CML cell line K562/ADM presented higher PI3K/ Akt activity than the sensitive one and was in accordance with the MDR phenotype (2).…”

Comparison of the effect of rhodium citrate-associated iron oxide nanoparticles on metastatic and non-metastatic breast cancer cells

“…MCF-7 cells were less sensitive to the NP treatment. Studies have already demonstrated the induction of resistance in MCF-7 cells (Tsou et al 2015). This feature in these cells can be related to data from the viability assay, which demonstrated a milder action on cytotoxicity over time.…”

Platinum sensitivity of ovarian cancer cells does not influence their ability to induce M2‐type macrophage polarization

“…Table S3 Changes in cellular morphology served as an endpoint for generation of resistant cell lines, as well as a reason for focusing on EMTrelated features. 52,53 Using the drug to which cells are sensitive (eg, the cisplatin on A2780 or doxorubicin on A280Cis) the CSC, MDR, and EMT-related genes are upregulated. Both drug-resistant cell lines exhibited the downregulation of CDH1 and upregulation of EMT transcription regulators SNAI1, SNAI2, and ZEB1 at mRNA level.…”

“…Cytostatic drugs were shown to induce the stem cell markers in ovarian cancer cells in the short term, 50,51 as well as selectively enrich for CSCs under continuous drug treatment. 52,53 Using the drug to which cells are sensitive (eg, the cisplatin on A2780 or doxorubicin on A280Cis) the CSC, MDR, and EMT-related genes are upregulated. Therefore, even a single dose of the drug may cause a significant change toward activating EMT, CSC, MDR profile, as previously reported.…”