Abstract: Background: Approximately 40% of patients with diffuse large B-cell lymphoma (DLBCL)
experience treatment resistance to the first-line R-CHOP regimen. ATP binding cassette (ABC) transporters and survivin might play a role in multidrug resistance (MDR) in various tumors. The
aim was to investigate if the coexpression of ABC transporters and survivin was associated with
R-CHOP treatment response. Methods: The expression of Bcl-2, survivin, P-glycoprotein/ABCB1,
MRP1/ABCC1, and BCRP/ABCC2 was analyzed using immunohistochemistry in tumor specimens
obtained from patients with DLBCL, and classified according to the treatment response as Remission,
Relapsed, and (primary) Refractory groups. All patients received R-CHOP or equivalent treatment.
Results: Bcl-2 was in strong positive correlation with clinical parameters and all biomarkers except
P-gp/ABCB1. The overexpression of MRP1/ABCC1, survivin, and BCRP/ABCC2 presented as
high immunoreactive scores (IRSs) was detected in the Refractory and Relapsed groups (p < 0.05
vs. Remission), respectively, whereas the IRS of P-gp/ABCB1 was low. Significant correlations were
found among either MRP1/ABCC1 and survivin or BCRP/ABCC2 in the Refractory and Relapsed
groups, respectively. In multiple linear regression analysis, ECOG status along with MRP1/ABCC1 or
survivin and BRCP/ABCG2 was significantly associated with the prediction of the R-CHOP treatment
response. Conclusions: DLBCL might harbor certain molecular signatures such as MRP1/ABCC1,
survivin, and BCRP/ABCC2 overexpression that can predict resistance to R-CHOP.
