Protein and messenger RNA (mRNA) expression of known resistance markers (breast cancer resistance protein (BCRP), multidrug resistance P-glycoprotein (MDR), lung cancer-related protein (LRP) and multidrug resistance protein 1 (MRP1)) were analysed by real-time polymerase chain reaction (PCR) and immunoblotting in 24 xenografts.
Since P-glycoprotein expression in lung tumors is generally low, these MDR lung cancer cell lines can be used as a model to study alternative mechanisms leading to multidrug resistance in this tumor type.
The current results taken together suggest that, aside from other known causes of lung cancer, such as tobacco smoke, the existence of polymorphisms in the ABCB1 gene and, specifically, the presence of the G2677T mutation can be crucial in conferring susceptibility to lung cancer.
The drug-resistant lung cancer cell line PTX250, which has been previously established by exposure to an anti-cancer drug paclitaxel, has an increased copy number in the MDR1/ABCB1 locus region.
The presence of glutathione S-transferase (GST) pi1 (GSTP1) or multidrug resistance gene 1 (MDR1) promoter methylation in lung cancer was studied for the first time to the authors' knowledge; and, to date, the clinical significance of methylation is not clear.
The present study assessed the reversing effect of AA on MDR and possible molecular mechanisms of AA action in MDR1-overexpressing cisplatin (DDP)-resistant lung cancer cells, A549/DDP.
The results of the present study revealed that docetaxel-resistant NSCLC cells also acquired cross-resistance to EGFR-TKI therapy through mechanisms other than ABCB1, that ABCB1 serves an important role in acquired resistance to docetaxel in lung cancer, and that combination therapy with elacridar can overcome ABCB1-mediated docetaxel resistance.
This study aimed to determine the relationship between the endogenous levels of P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP), lung resistance-related protein (LRP), glutathione-s-transferase-π (GST‑π) and topoisomerase IIα (TopoIIα) and intrinsic drug resistance in four human lung cancer cell lines, SK-MES-1, SPCA-1, NCI-H-460 and NCI-H-446, of different histological types.
This study characterized genetic variability of the ABCB1 (also known as MDR1), ABCC2 (MRP2) and ABCG2 (BCRP) genes, which are key players in the metabolism of many chemotherapeutic agents including those used in the treatment of lung cancer.
To ezamine the clinical relevance of P-glycoprotein, encoded by the human multidrug resistance gene (MDR1), to multidrug resistance in lung cancer, we examined the expression of MDR1 in 107 non-small cell lung cancer (NSCLC) specimens and 20 corresponding specimens of normal lung tissues.
To this end, we took advantage of the fact that the overexpression of MDR1 and MRP genes, two genes known to be associated with the development of drug resistance, is very common in lung cancer.
We analyzed joint association for CYP2A13 and ABCB1 polymorphisms in 2 independent lung cancer case populations (669 and 566 patients) and 1 common control population (749 subjects), and characterized the trans-acting function of the lung development-related transcription factor forkhead box A2 (FOXA2).
We reviewed characteristic resistance mechanisms in lung cancer including over-expression of ATP-binding cassette (ABC) transporters P-glycoprotein and structural, functional or expression alterations of β-tubulin (βII, βIII, βIV) which may devote to the development of acquired resistance to the Vinca alkaloids; multidrug-resistance proteins (MRP1, MRP2, MRP3) and RLIP76 protein have also been identified that probably play a significant role in intrinsic resistance.
We studied the expression of the genes encoding multidrug resistance associated protein (MDR1) and lung cancer associated resistance protein (LRP) in formalin-fixed, paraffin-embedded tumor samples from 52 patients treated for locally advanced breast cancer by means of induction chemotherapy followed by rescue mastectomy.