Correlation Between Galectin-3 And Lymphatic Metastasis And Pleural Metastasis In Lung Adenocarcinoma

ObjectiveGalectin-3 is a member of a large family ofβ-galactoside-binding animal lectins.It is multifunctional and involved in a variety of biological events including interactions with galactose-containing glycoconjugates,cell growth,proliferation, differentiation,adhesion,apoptosis,angiogenesis,immunity response,tumor progression and metastasis,and so on.The invasion and metastasis of tumor are the main reasons to claim the lives of patients with tumor,so inhibition of tumor aggressiveness and metastasis is one of the most important strategy in tumor treatment.In recent years,many investigasions have discovered that galectin-3 was overexpression or low expression in different meoplasms,the level of galectin-3 expression plays an important role in tumor invasion and metastasis.In thyroid nodule,galectin-3 has become a useful immunohistochemical marker for the identification of malignant or benign nodule.Studies found galectin-3 always was overexpression in lung cancer,but seldom studies focus on the correlation between galectin-3 and lymphatic metastasis and pleural metastasis in lung adenocarcinoma. Present study was performed to measure the expression of galetin-3 in primary adenocarcinoma of lung and metastasis of pleural,and investigate the correlation between galectin-3 and lymphatic metastasis and pleural metastasis in adenocarcinoma of lung.Methods and materials Sixty-three primary lung adenocarcinoma specimens and thirty-four adenocarcinoma metastatic of pleural specimens were cellected from Shandong provincial hospital.Immunohistochemistry Streptavidin-Peroxidase(SP)staining was used to detect the expression of galectin-3.In each case the immunohistochemical analyses consisted of an evaluation of the percentage of tumor cells stained(<25%=1;26%-75%=2;>76%=3) and the intensity of staining(no staining=0;weak staining=1;moderate staining=2;strong staining=3).An IP score(ie Intensity×Percentage) was used to determine the overall galectin-3 expression patterns in each primary tumors and the pleural metastasis.The location of galectin-3 in cells(nuclear and/or cytoplasmic staining)was also ascertained.All the statistical analyses were carried out using SPSS15.0,The significance of different groups were evaluated by means of x~2 test or the exact Fisher's test and P<0.05 was considered statistically significant.Results1.The location of galectin-3 expression were in cytoplasm and nuclear.While the main pattern was cytoplasmic.No cases with exclusive nuclear immunostaining were observed.2.In primary lung adenocarcinoma specimens the positive expression of galectin-3 in cytoplasm was 92.1%(58/63),in 20 cases a nuclear galectin-3 immunostaining were present(31.7%).The nuclear expression of galectin-3 in the cases with lymphatic metastasis was higher than the cases without lymphatic metastasis(P=0.03),and nuclear location of galectin-3 was also association with the clinical stages(TNMstages)(P<0.001).While high expression of galectin-3 in cytoplasm was not associated with lymphatic metastasis,clinical stage,age, gender and differentiation.3.In adenocarcinoma metastatic of pleural specimens the positive expression of galectin-3 in cytoplasm and nuclear were 97.1%(33/34) and 85.3%(29/34) respectively.Neither the cytoplasm staining nor nuclear staining were statistically significant between the group without lymphadenectasis and the other group with lymphadenectasis(P=0.382,P=0.059).In the cases of pleural metastatic adenocarcinoma,28 cases were poorly differentiated and 6 cases were moderately differentiated.There were also no discernible difference between moderately and poorly differentiated adenocarcinoma(P=0.389,P=0.433).4.The nuclear staining in pleural secondary adenocarcinoma was significantly higher than in the primary tumour(P＜0.05).ConclusionsGalectin-3 expresses highly in both lung adenocarcinoma specimens and adenocarcinoma metastatic of pleural specimens.Nuclear expression of galectin-3 can enhance the invasive and metastatic potential of lung adenocarcinoma,and it may be used as a biological marker of lymph node and/or pleural metastasis in the future.