BackgroundThe aim of this study was to clarify the clinicopathological outcome of serum relaxin-2 and tissues relaxin-2 expression levels in human primary osteosarcoma (OS), and to explore the roles of relaxin-2 inhibition and determine its possibility as a therapeutic target in human osteosarcoma.MethodsReal-time quantitative RT-PCR assay was performed to detect the expression of relaxin-2 mRNA in 36 cases of human osteosarcoma tissue samples. Serum relaxin-2 levels was measured in ELISA-based method in the 36 cases of osteosarcoma and 50 cases of controls. MTT and TUNEL assay was used to detect cell proliferation and apoptosis after relaxin-2 knockdown with siRNA transfection for 48 hs in vitro. Matrigel invasion and angiogenesis formation assay was used to detect cell metastasis and angiogenesis with HMEC-1 endothelial cells after relaxin-2 knockdown with siRNA transfection for 48 hs in vitro. The effects of relaxin-2 knockdown with anti- relaxin-2 mAb treatment on growth, apoptosis angiogenesis formation and lung metastasis in vivo was analyzed.ResultsThe results showed the levels of relaxin-2 mRNA expression in osteosarcoma tissue samples were significantly higher than those in the corresponding non-tumor tissue samples (P < 0.01), and the serum relaxin-2 levels were significantly higher in OS patients than in healthy controls (P < 0.01). The incidence of advanced stage cancer and hematogenous metastasis cancer in the high relaxin-2 mRNA expression group and high serum relaxin-2 levels groups was significantly higher than that in the low relaxin-2 expression group and low serum relaxin-2 levels groups, respectively. Knockdown of relaxin-2 by siRNA transfection in vitro inhibited proliferation, invasion and angiogenesis in vitro in MG-63 OS cells. In vivo, knockdown of relaxin-2 with anti- relaxin-2 mAb treatment inhibited tumor growth by 62% (P < 0.01) and the formation of lung metastases was inhibited by 72.4% (P < 0.01). Microvascular density was reduced more than 60% due to anti- relaxin-2 mAb treatment (P < 0.01).ConclusionsOur study suggests that overexpression of relaxin-2 is critical for the metastasis of human osteosarcoma. Detection of relaxin-2 mRNA expression or serum relaxin-2 levels may provide the first biological prognostic marker for OS. Furthermore, relaxin-2 is the potential molecular target for osteosarcoma therapy.

Uremic patients display differences in peritoneal microvascular endothelial function and microinflammatory states before peritoneal dialysis. Patients of the high transport group have higher MVD, increased expression of endothelial function markers (VEGF and eNOS), and the microinflammatory marker (IL-6). These observations are closely related to high baseline peritoneal transport.

Objective. To discuss the influence of high-dose recombinant human growth hormone (rhGH) therapy on serum vitamin D and insulin-like growth factor-1 (IGF-1) levels in school-age children with idiopathic short stature (ISS). Method. A total of 103 school-age children with ISS were selected from June 2016 to June 2020 in our hospital. The enrolled cases were divided into the low-dose group (n = 59) and high-dose group (n = 44) according to the treatment dose of rhGH. After the treatment, the height (Ht), height standard deviation score (Ht SDS), growth velocity (GV), and other indicators were recorded. The serum 25-hydroxy vitamin D [25-(OH)D] and IGF-1 levels of the two groups were tested, and the occurrence of adverse reactions was recorded. Results. After treatment, the high-dose group outperformed the low-dose group in various growth effect indicators such as Ht, Ht SDS, and GV ( P < 0.05 ). After treatment, the serum 25-(OH)D of children with ISS in the two groups increased significantly, but there was no significant difference between the two groups ( P > 0.05 ). After treatment, the serum IGF-1 of children with ISS in the two groups increased significantly, but there was no significant difference between the two groups ( P > 0.05 ). For children with ISS, adverse reactions induced by rhGH therapy were very rare. There was no significant difference in the incidence of adverse reactions induced by different doses of rhGH in the treatment of ISS ( P > 0.05 ). Conclusion. rhGH has definite efficacy in the treatment of ISS children, for it can significantly increase the annual growth rate of ISS children in a dose-dependent manner. High-dose rhGH for ISS has a better therapeutic effect. At the same time, regardless of the dose level of rhGH, serum 25-(OH)D and IGF-1 levels in children with ISS were increased, with less adverse reactions and higher safety.