title: The frequency and clinical relevance of multidrug resistance protein expression in patients with lymphoma.
abstract: OBJECTIVE
  Multidrug resistance is a cause of treatment failure in patients with malignant lymphoma; however, the frequency and clinical relevance of multidrug resistance protein expression are unclear. The present study aimed to investigate expression of the most common multidrug resistance proteins in a group of lymphoma patients.
  
  
  METHODS
  The study included 44 previously untreated lymphoma patients (non-Hodgkin's lymphoma [n = 21], non-malignant lymphadenopathy [n = 13], and Hodgkin's lymphoma [n = 10]). MDR1, MRP, and LRP expression was assessed via quantitative PCR of lymph node biopsy specimens.
  
  
  RESULTS
  In the non-Hodgkin's lymphoma group MDR1 was positive in 23.8% (5/21) of the patients, MRP was positive in 57.14% (12/21), and LRP was positive in 90.47% (19/21). In the non-malignant lymphadenopathy group, MDR1 was positive in 46.15% (6/13) of the patients, MRP was positive in 84.61% (11/13), and LRP was positive in 100% (13/13). In the Hodgkin's lymphoma group MDR1 was positive in 50% (5/10) of the patients, MRP was positive in 50% (5/10), and LRP was positive in 80% (8/10). MDR1, MRP, and LRP expression did not differ between the 3 groups. Furthermore, MDR1, MRP, and LRP expression wasn't associated with tumor stage, response to first-line therapy, the erythrocyte sedimentation rate, or C reactive protein, beta 2 microglobulin, serum lactate dehydrogenase, and albumin levels. Additionally, survival time in the MDR1- and MRP-positive, and MDR1- and MRP-negative patients did not differ (comparison of LRP was not possible due to the small number of LRP-negative patients).
  
  
  CONCLUSIONS
  According to the present findings, future studies should investigate alternative pathways of multidrug resistance in order to arrive at a better understanding of treatment failure in lymphoma patients.
authors.affiliation: Eskişehir Osmangazi University, Department of Hematology, Eskişehir, Turkey.
authors.forename: Eren
authors.initials: E
authors.lastname: Gündüz
authors.affiliation: Eskişehir Acıbadem Hospital, Medical Oncology Clinic, Eskişehir, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Dinçer
authors.affiliation: Eskişehir Osmangazi University, Department of Hematology, Eskişehir, Turkey.
authors.forename: Güniz
authors.initials: G
authors.lastname: Yıldız
authors.affiliation: Eskişehir Osmangazi University, Department of Biostatistics, Eskişehir, Turkey.
authors.forename: Cengiz
authors.initials: C
authors.lastname: Bal
authors.affiliation: Anadolu Health Center in Affiliation with Johns Hopkins Medicine, Bone Marrow Transplantation Center, Kocaeli, Turkey.
authors.forename: Zafer
authors.initials: Z
authors.lastname: Gülbaş
keywords: Hodgkin’s lymphoma; Multidrug resistance; Survival; non-Hodgkin’s lymphoma
references.citation: Leukemia. 2000 Jan;14(1):68-76
references.pmid: 10637479
references.citation: Blood. 2004 Jul 1;104(1):178-83
references.pmid: 15001473
references.citation: Science. 1992 Dec 4;258(5088):1650-4
references.pmid: 1360704
references.citation: Blood. 1997 May 15;89(10):3795-800
references.pmid: 9160686
references.citation: Nat Rev Cancer. 2002 Jan;2(1):48-58
references.pmid: 11902585
references.citation: Leukemia. 2000 Mar;14(3):467-73
references.pmid: 10720143
references.citation: APMIS. 2008 Sep;116(9):791-800
references.pmid: 19024599
references.citation: Hematol Oncol Clin North Am. 1995 Apr;9(2):239-49
references.pmid: 7642463
references.citation: J Biol Chem. 1986 Jun 15;261(17):7762-70
references.pmid: 3711108
references.citation: Pathology. 2009 Feb;41(2):127-32
references.pmid: 18972317
references.citation: Blood. 1994 May 1;83(9):2451-8
references.pmid: 7513198
references.citation: Leuk Res. 1993 Feb;17(2):149-56
references.pmid: 8094105
references.citation: J Natl Cancer Inst. 1989 Jan 18;81(2):116-24
references.pmid: 2562856
references.citation: Zhonghua Zhong Liu Za Zhi. 2009 Mar;31(3):199-202
references.pmid: 19615260
references.citation: Histopathology. 2001 Mar;38(3):209-16
references.pmid: 11260300
references.citation: Leuk Lymphoma. 1997 Dec;28(1-2):23-31
references.pmid: 9498700
references.citation: Cancer Res. 1970 Apr;30(4):1174-84
references.pmid: 5533992
references.citation: J Clin Oncol. 1999 Apr;17(4):1244
references.pmid: 10561185
references.citation: Cancer Res. 1992 Jul 1;52(13):3768-75
references.pmid: 1352183
references.citation: Histopathology. 1991 Aug;19(2):131-40
references.pmid: 1684559
references.citation: Blood. 1998 Mar 1;91(5):1508-13
references.pmid: 9473213
references.citation: Cancer. 2002 Dec 25;96(6):344-50
references.pmid: 12478682
references.citation: Br J Haematol. 1998 Dec;103(4):1083-91
references.pmid: 9886324
references.citation: Annu Rev Biochem. 2002;71:537-92
references.pmid: 12045106
references.citation: J Clin Oncol. 1991 Jan;9(1):17-24
references.pmid: 1670642
references.citation: Cancer Res. 1994 Apr 1;54(7):1649-52
references.pmid: 8137275
references.citation: Clin Cancer Res. 2000 Sep;6(9):3417-23
references.pmid: 10999723
references.citation: J Clin Oncol. 1993 Jan;11(1):109-15
references.pmid: 8093366
references.citation: C R Biol. 2006 Apr;329(4):241-54
references.pmid: 16644494
references.citation: Blood. 1998 Mar 15;91(6):2092-8
references.pmid: 9490695
references.citation: Clin Cancer Res. 1999 Sep;5(9):2426-30
references.pmid: 10499614
references.citation: J Clin Oncol. 1994 Nov;12(11):2453-9
references.pmid: 7964963
references.citation: Oncology. 2005;68(4-6):422-31
references.pmid: 16020972
references.citation: Blood. 1995 Aug 15;86(4):1515-24
references.pmid: 7632959
references.citation: Leuk Res. 2007 Apr;31(4):465-70
references.pmid: 17134750
references.citation: Int J Cancer. 1996 Jan 17;65(2):230-7
references.pmid: 8567122
references.citation: Cancer Res. 1993 Apr 1;53(7):1475-9
references.pmid: 7680954