Expressions Of Klotho&IGF-1in Gastric Carcinoma Tissues And Their Significance

Background and objectiveRecently, anti-aging gene Klotho was found to participate in the progression of several different human cancers and may affect the proliferation of tumor cells via modulating the insulin-like growth factor (IGF)-1signaling pathways. We use immunohistochemistry and western blot to detect the expressions of Klotho and IGF-1in the gastric adenocarcinoma tissues、the adjacent non-tumor tissues, gastric carcinoid tissues and normal gastric mucosa tissues, thus discussing their relations with each other in gastric cancer and their roles in the development of gastric cancer.Materials and methods1.Immunohistochemistry (IHC) methodIHC analysis was used to examine the expressions of Klotho and IGF-1protein in53cases of gastric carcinoma tissues,53adjacent carcinoma tissues,15gastric carcinoid tussues and10nomal gastric mucous tissues, respectively.2. Western bolt methodWestern bolt was used to detect the levels of Klotho and IGF-1protein in8cases gastric carcinoma tissues,8adjacent carcinoma tissues, 6gastric carcinoid tissues and6normal gastric mucous tissues.-Results1.immunohistochemical results1.1. The positive expression rates of Klotho protein in gastric carcinoma tissues, adjacent carcinoma tissues, gastric carcinoid tissues and normal gastric mucous tissues were69.8%(37/53)、90.5%(48/53)、87%(13/15)、100%(10/10)respectively. The Klotho expression in gastric carcinoma tissues was significant lower than in normal gastric mucous tissues and in adjacent carcinoma tissues (p<0.05). The positive expression rates of IGF-1protein in gastric carcinoma tissues, adjacent carcinoma tissues, gastric carcinoid tissues and normal gastric mucous tissues were81.1%(43/53)、53%(28/53)、40%(6/15)、20%(2/10) respectively. The IGF-1expression in gastric carcinoma tissues was significant higher than other groups (p<0.05).1.2. In gastric carcinoma, Klotho expression was related with lymph node metastasis、distant metastasis and tumor stage (p<0.05). However, no association was found between Klotho expression and gender, age, tumor location, histological differentiation, invasive depth as well as tumor size (p>0.05). IGF-1expression was associated with tumor size, lymph node metastasis, histological differentiation, invasive depth and tumor stage (p<0.05). However, no significant difference was observed between IGF-1expression and gender, age, tumor location as well as distant metastasis (p>0.05).1.3. In53cases of gastric carcinoma tissues, a negative correlation was observed between Klotho and IGF-1(r=-0.627, P<0.05)2. Western blot results2.1. The expression of Klotho protein in gastric carcinoma tissues was significant lower than in adjacent carcinoma tissues, gastric carcinoid tissues and normal gastric mucous tissues (p<0.05). The expression of IGF-1protein in gastric carcinoid tissues was significant higher than in adjacent carcinoma tissues as well as normal gastric mucous tissues (p<0.05).2.2. In28fresh tissues, the expression of Klotho protein was negatively correlated with expression of IGF-1protein (r=-0.763,P<0.05) protein.Conclusion1. The expression of Klotho protein was down-regulation in gastric carcinoma. The expression of Klotho protein was negatively correlated with tumor stage, lymph node metastasis and distant metastasis. There data suggest Klotho as a potential tumor suppressor.2. The expression of IGF-1protein gradually elevated with the sequence of normal gastric mucous tissues, gastric carcinoid tissues and gastric carcinoma. IGF-1expression was associated with histological differentiation, tumor stage, lymph node metastasis and invasive depth, which suggested IGF-1promote tumorigenesis and metastasis.3. The expression of Klotho protein was negatively correlated with expression of IGF-1protein. Therefore, Klotho might regulate gastric cancer cell proliferation through inhibiting IGF-1signaling pathways.