Objective: Leptin is a regulatory hormone which is mainly synthesized by adipocytes and regulates body fat mass. Leptin also has regulatory function on anterior pituitary. In this study, we have investigated the expression levels of leptin (Ob) and its receptor (Ob-R) in various types of pituitary adenomas and normal anterior pituitaries. Method: 50 pituitary adenoma cases between 2006 and 2011 were selected. Immunohistochemistry for leptin (Ob) was performed for each 10 cases of null cell, GH, ACTH, prolactin and FSH/LH secreting adenomas. Western blot was performed for leptin receptor (Ob-R) in 9 cases consisting of all five subtypes. Results: Immunohistochemical staining showed greater immunoreactivity for leptin in normal pituitaries compared to adenomas. Except for ACTH-secreting pituitary adenomas, all other four subtypes showed widespread and intense staining for leptin (P<0.0001). Null and FSH/LH-secreting subtypes were mainly showed cytoplasmic and nuclear staining. Western blot analysis showed leptin receptor expression in all types of adenomas except null cell. Objective: Primary malignant brain tumors often present local invasive growth. The study aimed to estimate the expression of KAI1 protein, MMP-2, CD44v6 and their correlation in gliomas of different grade of malignancy. Method: Expression of MMP-2, CD44v6 and KAI1 was evaluated on 154 formalin fixed paraffin-embedded tissue blocks divided into: pilocytic astrocytoma (n=15), fibrillary astrocytoma (n=17), anaplastic astrocytomas (n= 27), anaplastic oligodendrogliomas (n=27), glioblastoma multiforme (n=54) and normal brain tissue (n=14) using immunohistrochemistry. Results: MMP-2 and CD44v6 was observed frequently in gliomas with high grade of malignancy. KAI1 immunoreactivity was mainly observed in specimens with low degree of malignancy. MMP-2 and CD44v6 expression was significantly increased when the degree of malignancy of the gliomas increased (p<0.05). Whilst KAI1 expression increased when the degree of gliomas malignancy decreased (p = 0.03). Positive correlations between MMP-2 and CD44v6 (p=0.01) and inverse between KAI1 and MMP-2 expression (p=0.02) were found in gliomas.