Objective: To explore the expression of CXC chemokine 5 (CXCL5) in liver cancer cells and its effect on cell proliferation, migration and invasion.
Methods: Real-time (RT)-PCR and enzyme-linked immunosorbent assay (ELISA) were used to detect the mRNA and protein levels of CXCL5 in 4 liver cancer cell lines with different metastatic potentials (in ascending order: HepG2, SMMC7721, MHCC97L and MHCC97H). HepG2 with a low expression of CXCL5 was treated with CXCL5. There were four groups: 0 nmol/L CXCL5, 0.1 nmol/L CXCL5, 1.0 nmol/L CXCL5 and 10.0 nmol/L CXCL5. Cell proliferation was evaluated by cell counting kit-8 (CCK-8) assay. Transwell chambers and basement membrane matrix (Matrigel) were used to observe the cellular migration and invasion. Statistical analysis was performed with SPSS 16.0. Statistical comparison of the results was made by analysis of variance (ANOVA).
Results: The relative mRNA expression levels of CXCL5 in HepG2, SMMC7721, MHCC97L and MHCC97H were 0.002% ± 0.000%, 0.005% ± 0.000%, 1.030% ± 0.070% and 0.980% ± 0.190% (F = 33.88, P < 0.01) while their protein levels 14.3 ± 0.4, 25.7 ± 1.4, 82.8 ± 3.2 and 98.9 ± 1.7 respectively (F = 447.08, P < 0.01). The CCK-8 results showed that cell proliferation increased with the treatment of CXCL5, but no significant difference existed (F < 1.00, P > 0.05), cell numbers of migration of 0, 0.1, 1.0, 10.0 nmol/L CXCL5 groups were 29 ± 3, 56 ± 16, 113 ± 7 and 130 ± 15 (F = 51.94, P < 0.01), while cell numbers of invasion 17.3 ± 1.8, 33.0 ± 3.2, 65.7 ± 4.4 and 94.3 ± 3.5 respectively (F = 104.13, P < 0.01).
Conclusions: Liver cancer cells with high metastatic potential have a higher expression of CXCL5. And exogenous CXCL5 can increase the proliferation, migration and invasion of liver cancer cells with low metastatic potential. Thus CXCL5 may be associated with the metastasis of liver cancer.