CD147 expression in pituitary adenomas and its significance for clinical outcome

SummaryCD147, a transmembrane glycoprotein member of the immunoglobulin superfamily of receptors, is involved in invasion and angiogenesis of some types of tumors; but its roles and clinicopathologic significance in pituitary adenomas are not clear. Using immunohistochemistry and quantitative reverse transcriptase polymerase chain reaction, we measured the expression of CD147, matrix metalloproteinase–2, and Ki-67 in 74 pituitary adenomas and evaluated the associations of CD147 with matrix metalloproteinase–2, Ki-67 labeling index, clinicopathologic characteristics, and prognosis. The CD147 protein was expressed in 35 (87.5%) of 40 invasive and in 16 (47.1%) of 34 noninvasive pituitary adenomas; and matrix metalloproteinase–2, in 32 (80.0%) and in 14 (41.2%) of 34, respectively. The Ki-67 labeling index was 3.93% ± 2.48% for invasive samples and 1.32% ± 1.04% for noninvasive ones. In addition, the expression of CD147 was positively correlated with matrix metalloproteinase–2, Ki-67 labeling index, or both in invasive pituitary adenomas (P< .01 and P< .01, respectively). All of the 4 recurrent adenomas were concurrently positive for CD147 and matrix metalloproteinase–2, and the Ki-67 labeling indexes of all were greater than 3%. Thus, CD147 may play a pivotal role in the development and progression of invasive pituitary adenomas and also be a useful prognostic biomarker.