Multidrug resistance‐associated protein (MRP1) gene is strongly expressed in gastric carcinomas. Analysis by immunohistochemistry and real‐time quantitative RT‐PCR

Abstract

MRP1 gene is usually expressed in most gastric carcinomas and does not differ substantially from that observed in non-neoplastic gastric mucosa remote from the tumour. However, a decrease in MRP1 gene expression is found in some carcinomas. For accurate assessment of changes in MRP1 expression between tumour and normal tissues both protein and mRNA detection are necessary.

Membrane expression of MRP-1, but not MRP-1 splicing or Pgp expression, predicts survival in patients with ESFT

“…Although significant correlations between the mRNA and protein expression of MDR proteins have been described (Nooter et al , 1995; Cai et al , 1999; Yang et al , 2002; Lacueva et al , 2005; Haber et al , 2006), in the current study there was no correlation between Pgp protein and mRNA, or full and membrane MRP-1 protein and mRNA in primary ESFTs. These MDR proteins are highly posttranscriptionally regulated by processes such as methylation (Kantharidis et al , 1997; Ando et al , 2000; Qiu et al , 2007).…”

Expression and localization of ATP binding cassette (ABC) family of drug transporters in gastric hepatoid adenocarcinomas

“…Because the expression of ABC transporters confers multidrug resistance on tumour cells, 8–11 these findings suggest that the frequent expression of ABC transporters, including MRP1, MRP2 and MRP6, is involved in the chemoresistant mechanisms of hepatoid adenocarcinoma. Although a significant difference in MRP1 expression was observed between hepatoid and non‐hepatoid adenocarcinomas in our study, this result must be interpreted with caution, because in previous studies using immunohistochemistry or reverse transcriptase‐polymerase chain reaction, the MRP1 expression rate in gastric adenocarcinomas has varied from 12% to 89% 31–35 . Therefore, the MRP1 expression rate of hepatoid adenocarcinoma cases in our study (84.6%) was not remarkable when compared with some previous data.…”

Cytosine deaminase expressing human mesenchymal stem cells mediated tumour regression in melanoma bearing mice

“…The level of expression of orotate phosphoribosyltransferase and thymidylate synthase was not significantly different in these cells. Overexpression of multidrug resistance-associated protein MRP1 (ABCC1) was reported in 5FU resistant cancer cells [29,30]. ATPbinding cassette members ABC A3 (ATP-binding cassette, subfamily A, member 3), ABC G2 (Bcrp) and ABC B5 expression was also shown to be correlated with increased chemoresistance [31,32].…”