PubMedCrossRef 21. Colao A, Di Somma C, Pivonello R, Faggiano A, Lombardi G, Savastano S: Medical therapy

for clinically non-functioning pituitary adenomas. Endocr Relat Cancer 2008, 15:905–915.PubMedCrossRef 22. Syro LV, Ortiz LD, Scheithauer BW, Lloyd R, Lau Q, Gonzalez R, Uribe H, Cusimano M, Kovacs K, Horvath E: Treatment of pituitary neoplasms with temozolomide: a review. Cancer 2011, 117:454–462.PubMedCrossRef 23. McCormack AI, McDonald KL, Gill AJ, Clark SJ, Burt MG, Campbell KA, Braund WJ, Little NS, Cook RJ, Grossman AB, Robinson BG, Clifton-Bligh RJ: Low O6-methylguanine-DNA TPCA-1 order methyltransferase (MGMT) expression and response to temozolomide in aggressive pituitary tumours. Clin Endocrinol (Oxf) 2009, 71:226–233.CrossRef 24. Bush ZM, Longtine JA, Cunningham T, Schiff D, Jane JA Jr, Vance ML, Thorner MO, Laws ER Jr, Lopes MB: Temozolomide treatment for aggressive pituitary tumors: correlation of clinical outcome with O(6)-methylguanine KU55933 methyltransferase (MGMT) promoter methylation and

expression. J Clin Endocrinol Metab 2010, 95:E280–E290.PubMedCrossRef 25. Salehi F, Scheithauer BW, Moyes VJ, Drake WM, Syro LV, Manoranjan B, Sharma S, Horvath E, Kovacs K: Low immunohistochemical expression of MGMT in ACTH secreting pituitary tumors of patients with Nelson syndrome. Endocr Pathol 2010, 21:227–229.PubMedCrossRef 26. Salehi F, Scheithauer BW, Kovacs K, Horvath E, Syro LV, Sharma S, Manoranjan B, Cusimano M: O-6-methylguanine-DNA methyltransferase (MGMT) immunohistochemical expression in pituitary corticotroph adenomas. Neurosurgery 2012, 70:491–496.PubMedCrossRef 27. Lloyd RV, Scheithauer BW, Kuroki T, Vidal S, Kovacs K, Stefaneanu Verubecestat L: Vascular Endothelial Growth Factor (VEGF) expression in human pituitary adenomas and carcinomas. Endocr Pathol 1999, 10:229–235.PubMedCrossRef

28. Kurosaki M, Saegert W, Abe T, Ludecke DK: Expression of vascular endothelial growth factor in growth hormone-secreting pituitary adenomas: special reference to the octreotide treatment. Neurol Res 2008, 30:518–522.PubMedCrossRef 29. Gagliano T, Filieri C, Minoia M, Buratto M, Tagliati F, Ambrosio MR, Lapparelli M, Zoli M, Frank G, degli Uberti E, Zatelli MC: Cabergoline reduces Bcl-w cell viability in non functioning pituitary adenomas by inhibiting vascular endothelial growth factor secretion. Pituitary 2013, 16:91–100.PubMedCrossRef 30. Moshkin O, Syro LV, Scheithauer BW, Ortiz LD, Fadul CE, Uribe H, Gonzalez R, Cusimano M, Horvath E, Rotondo F, Kovacs K: Aggressive silent corticotroph adenoma progressing to pituitary carcinoma: the role of temozolomide therapy. Hormones (Athens) 2011, 10:162–167.CrossRef Competing interests The authors declare that they have no competing of interests. Authors’ contributions YW, JL and CM designed the research; YW, JL, YH, MT, SW, WL and ZL performed the research; WL and ZL evaluated the pathological sections and scored the extent of staining; JL and YW analyzed the data; JL, YW and CM wrote the paper, CM revised the paper.