No abstract available.
Breast* ; DNA* ; P-Glycoprotein*

Extranodal NK/T-cell lymphoma (ENKL) is a rare subtype of NHL (Non-Hodgkin lymphoma]. It occurs mostly in the nasal and paranal areas. Most of the cases are presented stage I/II. International prognostic index (IPI) can predict the outcome. However, better prognostic model is available such as NKIPI. Because of high expression of p-glycoprotein, ENKL is refractory to chemotherapy. Early stage disease can be bestly treated with concurrent chemoradiation. For advanced stage disease, new clinical trials are now being conducted.
Lymphoma ; P-Glycoprotein

No abstract available.
P-Glycoprotein* ; Stomach Neoplasms*

No abstract available.
Leukemia, Monocytic, Acute* ; P-Glycoprotein*

No abstract available.
Carcinoma, Transitional Cell* ; Humans* ; P-Glycoprotein* ; Urinary Bladder*

Oseltamivir is a substrate of P-glycoprotein, an efflux drug transporter encoded by ABCB1. The objective of this study was to assess the role of ABCB1 (c.1236C>T, c.2677G>T/A, and c.3435C>T) polymorphisms in the pharmacokinetics of oseltamivir and its active metabolite, oseltamivir carboxylate in humans. Nineteen healthy male subjects were enrolled, and their ABCB1 polymorphisms were evaluated. After the oral administration of 75 mg oseltamivir, the plasma concentrations of oseltamivir and oseltamivir carboxylate were measured. Pharmacokinetic analysis was carried out. Systemic exposure to oseltamivir and oseltamivir carboxylate was higher in the mutant group than in the wild-type and heterozygous groups. We suggest that ABCB1 polymorphisms affect the pharmacokinetics of oseltamivir in humans. Further studies in a large population are necessary to validate the results of this preliminary study (Clinical Trial Registration Information [CRIS] registry: http://cris.nih.go.kr, No. KCT0001903).
Administration, Oral ; Humans* ; Male ; Oseltamivir* ; P-Glycoprotein ; Pharmacokinetics* ; Plasma

OBJECTIVE: We determined the influence of 3-OMD in the protein binding of levodopa to estimate the effect of 3-OMD on the penetration of levodopa into brain. METHOD: P-glycoprotein in the brain may serve to limit drug penetration into the brain. Because it is not available as an experimental substance, but has similar binding properties with alpha 1 acid glycoprotein(AGP), we used AGP in this study. Additionally, we used blood plasma to see the affinity of plasma binding of levodopa. The final concentration of chemicals used in this study were 125, 250, 500, 1000, 2000, 4000 microgram/l for levodopa and 0, 1250, 5000, 10,000 microgram/l for 3-OMD, 1 mg/l for AGP. The free fraction of levodopa in blood plasma and AGP were separated by ultrafiltration method and determined by beta-counter, respectively. RESULTS: We found that levodopa did not bind with AGP, but only 22-24% from 125 microgram/l to 4000 microgram/l of it bound with blood plasma. The addition of 3-OMD to the blood plasma did not significantly change the binding of levodopa. CONCLUSIONS: We can conclude that 3-OMD does not influence the penetration of levodopa into brain. These small amount of the binding does not expect to influence to other drugs on the binding with plasma.
Brain ; Drug Interactions ; Levodopa* ; P-Glycoprotein ; Plasma* ; Protein Binding ; Ultrafiltration

OBJECTIVES: The purpose of this study was to evaluate expression of cyclooxygenase-2 (COX-2) and P-glycoprotein (P-gp) in ovarian epithelial carcinomas, to find out the correlations between their expression and clinicopathological parameters, and to evaluate the response to treatment and clinical outcome according to their expression. METHODS: Immunohistochemical studies of COX-2 and P-gp were carried out in 64 cases that were treated with ovarian epithelial carcinomas at Department of Obstetrics and Gynecology, Korea University Hospital, Korea University from 1996 to 2005. RESULTS: COX-2 over-expression was detected in 20 (31.2%) cases and was significantly higher in non-responder than responder to chemotherapy (56.2% versus 22.9%, respectively; P=0.012). The patients of COX-2 overexpression showed shorter overall survival (P<0.001). Over-expression of P-gp was detected in 15 (23.4%) cases was significantly higher in non-responder than responder to chemotherapy (56.2% versus 12.5%, respectively; P<0.001). The patients of P-gp overexpression showed shorter overall survival (P= 0.042). CONCLUSION: COX-2 and P-gp overexpression could provide additional information to identify ovarian carcinoma patients with poor chance of response to chemotherapy.
Cyclooxygenase 2* ; Drug Therapy ; Gynecology ; Humans ; Korea ; Obstetrics ; P-Glycoprotein* ; Prognosis

Overexpression of the MDR1 gene product, P-glycoprotein (Pgp), has been shown to be one of the mechanism underlying the development of mutidrug resistance in bladder cancer. Recently, mutant p53 has been shown to stimulate the P-glycoprotein and to being strongly associated with tumor progression and malignant biological behavior, whereas wild-type p53 repressed this activity. To evaluate the correlation of p53 expression with P-glycoprotein, to study expression pattern of two parameters according to histologic grade, tumor stage and recurrence, we examined expression of p53 and Pgp in paraffin-embedded tissues from 59 transitional cell carcinoma of bladder. Expressions of p53 and Pgp Protein were detected by immunohistochemical analysis using the monoclonal antibody BP53.12 and JSB-1. Among the cases of 59 patients, 36 were from patients of superficial bladder cancer, 23 were from invasive bladder cancer. Median follow-up duration was 31.8 months (1~55 months). The results were as follow: 1. p53 was detected in 34% (20/59), and Pgp in 42% (25/59) of the bladder cancer. 2. Eight out of the 20 specimens with p53 positive stain expressed positive Pgp expression, as compared to 17 out of the 39 specimens without p53 positive stain. This result showed that Pgp expression was not associated with p53 expression (p=0.98), suggesting that mutant p53 does not induce Pgp expression in bladder cancer. 3. Seven of 12 patients with p53 positive stain revealed tumor recurrence, whereas 2 of 24 patients without p53 positive stain showed recurrence in superficial bladder cancer. There ia s significant correlation between p53 expression and recurrence (p=0.0025). 4. Expression of p53 and Pgp showed enhanced positive tendency according to higher clinicopathological stage, but difference was not statistically significant. Also positivity of Pgp expression according to histologic grade was observed significantly higher in case with high grade tumors (14/25, 56%) than in case with low grade tumors (10/34, 29%) (p=0.03). These results show that superficial bladder cancers exhibiting expression of p53 protein are associated with a higher rate of recurrence. This study also suggests that Pgp expression is significantly more common in higher grade, and mutant p53 does not induce Pgp expression in bladder cancer.
Carcinoma, Transitional Cell ; Follow-Up Studies ; Humans ; P-Glycoprotein* ; Recurrence ; Urinary Bladder Neoplasms* ; Urinary Bladder*

BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) is a drug-resistant tumor. The expression of a multidrug resistant gene, P-glycoprotein (P-gp) is a major mechanism of drug resistance. The aims of our study were, firstly, to observe the expression rate of P-gp in HCC tissue obtained by percutaneous fine needle aspiration (PCNA) from stage IV HCC patients; secondly to examine the association between P-gp and chemotherapeutic response; and finally to investigate the correlation between p53 protein expression and P-gp expression. Subjects and METHODS: We studied 29 cases of stage IV HCC treated by systemic chemotherapy. Expression of P-gp and p53 were evaluated by immunohistochemical staining of HCC tissue with human monoclonal antibody, JSB-1 (Anti P-gp) and DO-7 (Anti p53), respectively. We analyzed the results of immunohistochemical staining of HCC tissues of the patients in relation to chemotherapeutic response and other clinical characteristics. RESULTS: The expression rate of P-gp was 27.6%. Partial response to anti-cancer chemotherapy was observed in 16.7% of the patients. Although we could not see a statistically significant association between P-gp expression and chemotherapeutic response, none of the responsive patients showed P-gp expression. p53 protein expression was found in 45% of the patients. There was no significant correlation between p53 protein expression and P-gp expression. CONCLUSIONS: Although the number of our study subjects was small, chemotherapy- responsive patients didn't show P-gp expression. P-gp expression might be used as a predictor of response to potentially toxic anti-cancer chemotherapy in HCC patients. Further study is warranted to confirm our results.
Biopsy, Fine-Needle ; Carcinoma, Hepatocellular* ; Drug Resistance ; Drug Therapy* ; Humans ; P-Glycoprotein*