Abstract
Abstract 3103
Non-Hodgkin's lymphoma (nHL) represent heterogenous group of lymphoid malignancies derived from B and T lymphocytes, NK cells or histiocytes. Most of lymphomas are B-cell origin. Lymphoma cells can migrate to other organs and their migration could be linked to chemokines and their receptors. Chemokine receptors are expressed by many cell populations, including lymphoid cells, and their main function is lymphocytes. Chemokine receptors guide lymphocytes homing, chemotaxis, adhesion and interplaying between immunologic system response cells. They are also responsible for cancer metastasis, including also dissemination of Hodgkin's and non-Hodgin's lymphomas.
The purpose of the study was to determinate expression of genes coding chemokine receptors: CXCR4, CCR1, CCR2a, CCR2b, CCR3, CCR5, CCR7 and CCR8 in lymphoma lymph nodes comparing to their expression in reactive lymph nodes. We also wanted to analyze the influence of chemokine receptor gene expression on lymphoma patient survival.
Chemokine receptor gene expression was evaluated in 63 lymphoma lymph nodes taken from patients (31 women and 32 men, aged 18–81 years; median age 43 years) at the moment of diagnosis. In 25 samples of reactive lymph nodes (taken from 15 women and 10 men; aged 18–59; median age 32 years) expression of chemokine genes was also studied as a control group.
Gene expression of chemokine receptors CXCR4, CCR1, CCR2a, CCR2b, CCR3, CCR5, CCR7 and CCR8 was measured by reverse transcription (RT)-polymerase chain reaction method. Gene expression was estimated in arbitrary units (AU) from 0 to 3 AU points scale. PCR was conducted using primer pairs for CXCR4 (sens GAC CGC TAC CTG GCC ATC, antisens GGC AGC CAA CAG GCG AAGg A, 345 bp), CCR2a (sens GTA TCT CTC GGT GTT CTT CC, antisens TCT AGG CTC CTT CTT TGT CCT G, 271 bp), CCR2b (sens GTA TCT CTC GGT GTT CTT CC, antisens ACC AGC CGA GAC TTC CTG CT, 163 bp) CCR3 (sens TCC TTC TCT CTT CCT ATC AAT, antisens GGC AAT TTT CTG CAT CTA, 312 bp), CCR5 (sens AAT CTT CTT CAT CAT CCT CC, antisens TCT CTG TCA CCT GCA TAG C, 506 bp), CCR7 (sens CTG GTG GTG GCT CTC CTT GT, antisens GCC AGG TTG AGC AGG TAG GT, 271 bp), CCR8 (sens GGT TGG TGC TCA TTG TGG TC, antisens AGT CTA CGC TGG AGG AAC GG, 345 bp). Statistical analysis was performed using the CSS Statistica for Windows (version 7.0) software. Probability values <0.05 were considered statistically significant.
There was significantly higher expression of CCR1 and CCR8 gene in lymphoma lymph nodes comparing to controls (p<0.05), while CCR5 and CCR7 gene expression was significantly lower in lymphoma lymph nodes (p<0.05) comparing to reactive lymph nodes. CXCR4, CCR2a, CCR2b, CCR3 expression did not differ between lymphoma and control groups. The patients with higher expression of CCR7 gene had significantly longer survival comparing to those with lower expression (p=0.048). Expression of CCR7 was negatively correlated with IPI (p=0.036, coefficient = -0.32). Higher expression of CCR5 gene was positively correlated with Ki-67 (p=0,016, coefficient = 0.34), stage of disease (p=0.048, coefficient = 0.029) and international prognostic index score - IPI (p=0,047, coefficient = 0.298). We also found positive correlation between CCR8 gene expression and IPI (p=0.039, coefficient = 0.32).
Lower expression of CCR7 gene is combined with longer survival of nHL patients. As there are positive correlations between CCR5 expression and Ki-67 proliferation marker and IPI as well as CCR8 and IPI in non-Hodgkin's lymphoma, those receptors can promote tumour progression.
No relevant conflicts of interest to declare.
Author notes
Asterisk with author names denotes non-ASH members.
