Objective        To investigate the expression levels of insulin-like growth factor 1 (IGF-1) and its receptor (IGF-1R) in human non-functioning pituitary adenomas and their relationships with tumor invasion and recurrence.       Methods      Sixty specimens of non-functioning pituitary adenomas collected in surgery in our department from August 2012 to May 2014 were classified into invasive recurrent group (n=16)

invasive non-recurrent group (n=24) and non-invasive non-recurrent invasive group (n=20) according to the clinical data of the corresponding patients. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the mRNA expression levels of IGF-1 and IGF-1R. Western blot assay and immunohistochemical assay were employed to measure the protein levels of IGF-1

IGF-1R and its downstream molecule of associated signaling pathway

VEGF.       Results      The mRNA expression levels of IGF-1 and IGF-1R and the protein expression levels of IGF-1

IGF-1R and VEGF were significantly higher in invasive recurrent groups than in invasive non-recurrent group (P0.05)

and in the invasive non-recurrent group than non-invasive non-recurrent group (P0.05). The correlation analysis revealed that there was a positive correlation between the protein levels of IGF-1and IGF-1R (r=0.85

r=0.80

P0.05)

and between those of IGF-1R and VEGF (r=0.74

r= 0.70

P0.05) in invasive recurrent group and invasive non-recurrent group respectively. Positive correlation was also found between the protein levels of IGF-1 with IGF-1R in non-invasive non-recurrent group (r=0.73

P0.05)

but no obvious relation was found in the levels of IGF-1R with VEGF (P0.05).        Conclusion      The expression of IGF-1

IGF-1R and VEGF is enhanced in the invasiveness and recurrence of non-functioning pituitary adenomas. The 3 molecules may play synergetic roles and are involved in the occurrence and development of invasive growth and recurrence of the tumor.