Changes in P-glycoprotein expression in gastric carcinoma with respect to distant gastric mucosa may be influenced by p53

ATP‐binding cassette superfamily transporter gene expression in human soft tissue sarcomas

“…demonstrated a positive correlation between P‐gp and the nuclear accumulation of p53 protein in breast cancer using an immunohistochemical method. Similar immunohistochemical results have been reported in gastric cancer13 and oral squamous cell carcinoma 14. A significant correlation between p53 mutation and MDR1 mRNA expression has also been documented in advanced colon cancer34 and in nonsmall cell lung cancer 35.…”

“…A tumor suppressor protein could also influence the expression of a drug‐resistant gene. Several authors have observed that wild‐type p53 repressed the transcription of the MDR1 gene,9, 10, 11 while P‐gp expression showed a positive correlation with p53 nuclear expression in breast cancer,12 gastric cancer13 and oral squamous cell carcinoma 14. Wild‐type p53 has also been shown to repress the transcription of the human MRP1 promoter,15, 16, 17 whereas aberrant p53 expression is correlated with increased MRP1 expression in nonsmall cell lung cancer18 and gastrointestinal tract cancer 19, 20.…”

Association between ABCB1 Immunohistochemical Expression and Overall Survival in Gastric Cancer Patients

“…The positivity of ABCB1 protein between 25% and 71% of GC cells was associated with poor prognosis (Lacueva et al, 2000;Xie et al, 2004;Wei et al, 2005). Similarly, this study showed that patients with GC and ABCB1 protein positive had poor prognosis (p=0.03).…”

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

“…Our results are in agreement with other studies that have screened MRP1 expression in gastric mucosa by immunohistochemistry 11 or non-quantitative RT-PCR, 16 and they confirm that gastric carcinomas have an intrinsic MDR phenotype as we observed previously studying other ABC transmembrane transport proteins. 28 Interestingly, the real-time quantitative RT-PCR permitted us to detect an important interindividual variability in MRP1 mRNA levels, especially among samples of non-neoplastic gastric mucosa, which was not so clearly observed by immunohistochemistry.…”