Expression and clinical significance of CCL5 in patients with esophageal carcinoma / 中华肿瘤杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the expression and significance of CCL5 in patients with esophageal carcinoma.</p><p><b>METHODS</b>Using reverse transcriptase polymerase chain reaction (RT-PCR), the expressions of CCL5/CD8/granzyme B/perforin in tumor and corresponding adjacent tissues from esophageal carcinoma patients were examined. Flow cytometry (FACS) was used to detect the percentages of CD8(+) T cells and CCR5(+)CD8(+) T cells in TIL and PBMC from the patients. Transwell assay was performed to study the effect of CCL5 on the migration of T cells in vitro. T test and Spearman correlation analysis were performed.</p><p><b>RESULTS</b>The mRNA expressions of CCL5 and perforin were 0.348 2 ± 0.300 1 and 0.181 9 ± 0.118 6, respectively, in the tumor samples, while their expressions in adjacent samples were 0.279 6 ± 0.138 0 and 0.118 0 ± 0.109 8, respectively, with no statistically significant differences between them (P > 0.05 for both). The mRNA expressions of CD8 and granzyme B were significantly higher in the tumor tissues than in adjacent tissues (0.464 9 ± 0.300 8 vs. 0.279 0 ± 0.173 4, 0.648 7 ± 0.516 0 vs. 0.469 7 ± 0.259 1; P < 0.05 for both). The relative expression of CCL5 was positively correlated with that of CD8, perforin and granzyme B (r(CD8) = 0.272, P = 0.034; r(perforin) = 0.305, P = 0.026; r(granzymeB) = 0.108, P = 0.012) in the tumor sites. FACS data revealed that the proportions of CD8(+) T cells in TIL and PBMC were (45.86 ± 16.09)% and (34.05 ± 15.07)%, respectively, showing a significant difference (P = 0.022). Similarly, CCR5(+)CD8(+) T cells fraction in TIL (48.12 ± 26.75)% was much higher than that in PBMC (19.53 ± 13.67) % (P < 0.001). Transwell assay showed that CCL5 protein enhanced the migration of T cells, supporting that CCL5 is crucial for CD8(+) T cells recruitment in vivo. Intriguingly, CCL5 expression was down-regulated in advanced patients (stage IIb-IV). The accumulation of CD8(+) T cells and CCR5(+)CD8(+) T cells was strongly reduced in advanced patients, suggesting that CCL5 expression may be involved in the local control of the disease and its reduction may be involved in disease progression.</p><p><b>CONCLUSIONS</b>The current data indicate the involvement of CCL5 in the regulation of CD8(+) T cell entry into tumor lesions in esophageal carcinoma patients. This process may affect the disease status and potentially as a prognostic factor for cancer patients. Enhancing local CCL5 expression in tumor lesions may represent a novel strategy in esophageal cancer therapy.</p>