1. Applied Physiology Research Center, Cardiovascular research institute, Isfahan University of Medical Sciences, Isfahan, Iran. 2. Isfahan Cardiovascular research center, Department of Pharmacology, Cardiovascular research institute, Isfahan University of Medical Sciences, Isfahan, Iran. 3. Applied Physiology Research Center, Cardiovascular research institute, Isfahan University of Medical Sciences, Isfahan, Iran.
Abstract
Introduction
Lipopolysaccharide (lps) is an endotoxin derived from the outer membrane of gram-negative bacteria. toll-like receptor 4 (tlr4) is the signaling receptor for lps. while tlr4 activation can promote antitumor immunity, it can also result in increased tumor growth and immunosuppression. the aim was to investigate the effect of lps on melanoma tumor growth and tlr4 expression.
Methods
C57bl/6 mice were divided into 2 groups(n=7): control, lps. in lps group before subcutaneous injection of b16f10 melanoma cells, the cells were treated with lps (5µg/ml) for 24 hours. in control, group mice were injected with untreated cells. mice were sacrificed ten days after that palpable tumor developed. tumor volume was measured with vernier calipers. the expression of tlr4 mrna in tumor tissue was evaluated by qrt-pcr.tlr-4 protein expression was determined by immunohistochemistry( ihc) assay.
Results
A significant increase of tlr4 mrna expression was observed in the lps group and tlr-4 protein expression was significantly increased compared with the control group. treatment of cells with lps before injection led to a significant increase in tumor volume compared to the mice that received untreated cells.
Conclusion
These findings indicated that tlr4 may participate in the progression of melanoma and provide a new therapeutic target.
