The Expression Of Cavelolin-1 In Laryngeal Carcinoma And The Correlation With Tumor Angiogenesis

ObjectiveTo investigate the relation and clinical significance among the expression of caveolin-1 andVEGF in laryngeal carcinoma with tumor angiogenesis.Tumor samples and clinic data from 40 pations with laryngeal squamous cell carcinoma(LSCC) and operated on at Department of Otolaryngology and Head Neck Surgery of the FirstHospital of Shanxi Medical University between 2008 and 2010 were studied,20 cases withoutlymph node metastasis laryngeal carcinoma specimens,20 cases of laryngeal carcinomaspecimens with lymph node metastasis,and normal control was 8 cases of normal laryngealmucosa.Methods1.Forty cases of laryngeal squamous cell carcinoma (LSCC) and eight cases of normallaryngeal mucosa were respectively stained for caveolin-1,CD34 and VEGF by immunohistochemistry.2.Forty cases of laryngeal squamous cell carcinoma (LSCC) and eight cases of normallaryngeal mucosa were respectively stained for caveolin-1mRNA and VEGFmRNA by RT-PCR.Results1.caveolin-1 protein was mainly expressed in cell membrane and cytoplasm,the positive rateof 75.0% in normal tissue,laryngeal carcinoma without lymph node metastasis was 25.0%,laryngeal carcinoma with lymph node metastasis was 65.0%,The caveolin-1mRNA of the threegroups were 0.701±0.073, 0.450±0.050 and 0.572±0.061, irrespective of the level of gene orprotein level differences among the three groups was statistically significant(P＜0.05),pairwisecomparisons were also significant differences (P＜0.05),The expression level of caveolin-1 inlaryngeal carcinoma with lymph node metastasis was significantly higher than that of caveolin-1in laryngeal carcinoma without lymph node metastasis (P＜0.05), The expression level ofcaveolin-1 and cervical lymph node metastasis were significantly associated(P＜0.05).2. VEGF expressed in the cytoplasm of tumor cells,the positive rate in normal tissue was25%,laryngeal carcinoma without lymph node metastasis was 55%,laryngeal carcinoma withlymph node metastasis was 75%.The VEGFmRNA of the three groups were 0.614±0.321,0.801±0.473 and 1.413±0.586,irrespective of the level of gene or protein level differences among thethree groups was statistically significant (P＜0.05),pairwise comparisons were also significant differences (P＜0.05),The expression level of VEGF in laryngeal carcinoma with lymph nodemetastasis was significantly higher than that of caveolin-1 in laryngeal carcinoma without lymphnode metastasis (P＜0.05),The expression level of caveolin-1 and cervical lymph nodemetastasis were significantly associated.3.The mean CD34-MVD value of normal tissue, laryngeal carcinoma without lymph nodemetastasis and laryngeal carcinoma with lymph node metastasis were 3.42±1.15,21.34±4.62and 30.19±2.60,differences among the three groups was statistically significant (P＜0.05),pairwise comparisons were also significant differences (P＜0.05).Between MVD andVEGF was positively correlated (r=0.635, P＜0.01), A significant correlation was found betweenMVD and caveolin-1 in 40 cases of laryngeal tissue (r = 0.424, P＜0.05).4.From the protein and gene levels,normal and laryngeal carcinoma without lymph nodemetastasis between the expression of caveolin-1 and VEGF was negatively correlated (P＜0.05),positive relevance was found between caveolin-1 and VEGF expression in laryngealcarcinoma without lymph node metastasis and laryngeal carcinoma with lymph node metastasis((P＜0.05).ConclusiConclusionLaryngeal cancer cells can synthesize and secrete large amounts of VEGF,which plays acatalytic role in tumor angiogenesis.The tumor microvessel density is an important indicator oftumor angiogenesis.This study show that the expression level of caveolin-1 in normal tissue washigher than that of caveolin-1 in laryngeal carcinoma without lymph node metastasis,and anegative correlation with microvessel density,suggesting that caveolin-1 inhibits tumorangiogenesis,which may be associated with inhibition of VEGF expression;the expression levelof caveolin-1 in laryngeal carcinoma with lymph node metastasis was higher than that ofcaveolin-1 in laryngeal carcinoma without lymph node metastasis,and was positively correlatedwith microvessel density,suggesting that caveolin-1 promotes tumor angiogenesis,which may berelated to caveolin-1 mutation or promotion of VEGF expression,thereby promoting tumorinvasion and metastasis.