TY - JOUR
T1 - Immunohistochemical analysis of VEGF-C/VEGFR-3 system and lymphatic vessel extent in normal and adenomatous human pituitary tissues
AU - Onofri, C.
AU - Losa, M.
AU - Uhl, E.
AU - Stalla, G. K.
AU - Renner, U.
PY - 2008/3
Y1 - 2008/3
N2 - The angiogenic growth factor Vascular Endothelial Growth Factor-C (VEGF-C) and its receptor VEGFR-3 are also known to be implicated in the development of lymphatic vessels. We assessed the expression of VEGF-C and VEGFR-3, together with blood and lymphatic vessel extents and proliferation index (PI) values, by immunohistochemistry (IHC) in 6 normal human pituitary glands and 53 pituitary adenomas of different tumour grade, on consecutive tissue sections. VEGF-C was detected in around 10% of the endocrine cells in normal pituitary tissue, while this gland was devoid of lymphatic vascularization and showed very few vessels positive for VEGFR-3. Concerning tumour tissue, most of the adenomas showing VEGF-C immunoreactivity (21/47) were positive in 60% of the tumour cells and the ones positive for VEGFR-3 showed a number of immunostained vessels higher than those observed in the normal pituitary. Most of the tumours positive for VEGFR-3 did not show any LYVE-1 positive vessels (18/53), suggesting that at least in these cases, VEGFR-3 is expressed on blood vessels. Nevertheless, we observed a significant association between low expression of VEGFR-3 and low lymphatic vessel number, suggesting that VEGFR-3 might be involved in the starting of de novo lymphangiogenesis in this tumour type. Moreover, tumours bearing lymphatic vessels showed the tendency to shift towards a more aggressive behaviour (high tumour grade and high PI). In conclusion, the VEGF-C/VEGFR-3 system might be involved in controlling tumour angiogenesis in the pituitary adenomas lacking lymphatic vessels, but may also play a role in starting the process of tumour lymphangiogenesis.
AB - The angiogenic growth factor Vascular Endothelial Growth Factor-C (VEGF-C) and its receptor VEGFR-3 are also known to be implicated in the development of lymphatic vessels. We assessed the expression of VEGF-C and VEGFR-3, together with blood and lymphatic vessel extents and proliferation index (PI) values, by immunohistochemistry (IHC) in 6 normal human pituitary glands and 53 pituitary adenomas of different tumour grade, on consecutive tissue sections. VEGF-C was detected in around 10% of the endocrine cells in normal pituitary tissue, while this gland was devoid of lymphatic vascularization and showed very few vessels positive for VEGFR-3. Concerning tumour tissue, most of the adenomas showing VEGF-C immunoreactivity (21/47) were positive in 60% of the tumour cells and the ones positive for VEGFR-3 showed a number of immunostained vessels higher than those observed in the normal pituitary. Most of the tumours positive for VEGFR-3 did not show any LYVE-1 positive vessels (18/53), suggesting that at least in these cases, VEGFR-3 is expressed on blood vessels. Nevertheless, we observed a significant association between low expression of VEGFR-3 and low lymphatic vessel number, suggesting that VEGFR-3 might be involved in the starting of de novo lymphangiogenesis in this tumour type. Moreover, tumours bearing lymphatic vessels showed the tendency to shift towards a more aggressive behaviour (high tumour grade and high PI). In conclusion, the VEGF-C/VEGFR-3 system might be involved in controlling tumour angiogenesis in the pituitary adenomas lacking lymphatic vessels, but may also play a role in starting the process of tumour lymphangiogenesis.
KW - Lymphatic vessels
KW - LYVE-1
KW - Pituitary adenomas
KW - VEGF-C
KW - VEGFR-3
UR - http://www.scopus.com/inward/record.url?scp=42049112971&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=42049112971&partnerID=8YFLogxK
U2 - 10.1055/s-2007-992120
DO - 10.1055/s-2007-992120
M3 - Article
C2 - 18205092
AN - SCOPUS:42049112971
VL - 116
SP - 152
EP - 157
JO - Experimental and Clinical Endocrinology and Diabetes
JF - Experimental and Clinical Endocrinology and Diabetes
SN - 0947-7349
IS - 3
ER -