{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T16:00:05Z","timestamp":1775059205290,"version":"3.50.1"},"reference-count":27,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2012,1,31]],"date-time":"2012-01-31T00:00:00Z","timestamp":1327968000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Background: Gastro-entero-pancreatic\/neuroendocrine (NET) tumors are highly vascularized neoplasms. However, our knowledge concerning circulating levels of the angiogenic factors in NET patients still remains insufficient. Methods: The aim of this study was to measure plasma concentrations of VEGF, angiopoietin 1 (Ang-1), angiopoietin 2 (Ang-2), soluble Tie-2, endostatin, osteopontin (OPN) and chromogranin A (CgA) in 36 NET patients and 16 controls. Results: Only the plasma concentrations of Tie-2 and CgA were higher in NET patients as compared to controls. These levels were within the reference range in controls; however one control demonstrated slightly elevated Tie-2 and 4 elevated CgA. Similarly, in the subgroup of patients with carcinoid syndrome, only Tie-2 and CgA concentrations were higher than those in patients with non-functioning NETs. In turn, in the subgroup of metastatic patients, only Ang-2 levels were higher than in those with localized disease. A positive correlation was found between Ang-2 and Tie-2 levels in metastatic patients and between Ang-1 and Tie-2 in localized NETs. Conclusions: The plasma concentration of Tie-2 is proposed as an additional marker for NET patients and seems to be similarly effective as the currently used CgA level. Moreover, higher plasma levels of Ang-2 together with the positive correlation between Ang-2 and Tie-2 levels in metastatic subjects, implies that cases with a Tie-2 level above the upper limits, together with higher level of Ang-2 seem to be highly predictive of metastases. <\/jats:p>","DOI":"10.3390\/ijms13021444","type":"journal-article","created":{"date-parts":[[2012,1,31]],"date-time":"2012-01-31T11:06:27Z","timestamp":1328007987000},"page":"1444-1460","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Elevated Peripheral Blood Plasma Concentrations of Tie-2 and Angiopoietin 2 in Patients with Neuroendocrine Tumors"],"prefix":"10.3390","volume":"13","author":[{"given":"Gabriela","family":"Melen-Mucha","sequence":"first","affiliation":[{"name":"Department of Immunoendocrinology, Chair of Endocrinology, Medical University of Lodz, Dr Sterling Str. No. 3, 91-425 Lodz, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Agata","family":"Niedziela","sequence":"additional","affiliation":[{"name":"Department of Immunoendocrinology, Chair of Endocrinology, Medical University of Lodz, Dr Sterling Str. No. 3, 91-425 Lodz, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Slawomir","family":"Mucha","sequence":"additional","affiliation":[{"name":"Department of Clinical Endocrinology, Chair of Endocrinology, Medical University of Lodz, Dr Sterling Str. No. 3, 91-425 Lodz, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ewelina","family":"Motylewska","sequence":"additional","affiliation":[{"name":"Department of Immunoendocrinology, Chair of Endocrinology, Medical University of Lodz, Dr Sterling Str. No. 3, 91-425 Lodz, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hanna","family":"Lawnicka","sequence":"additional","affiliation":[{"name":"Department of Immunoendocrinology, Chair of Endocrinology, Medical University of Lodz, Dr Sterling Str. No. 3, 91-425 Lodz, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jan","family":"Komorowski","sequence":"additional","affiliation":[{"name":"Department of Clinical Endocrinology, Chair of Endocrinology, Medical University of Lodz, Dr Sterling Str. No. 3, 91-425 Lodz, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Henryk","family":"Stepien","sequence":"additional","affiliation":[{"name":"Department of Immunoendocrinology, Chair of Endocrinology, Medical University of Lodz, Dr Sterling Str. 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