Hanna Ławnicka

Modulation of ghrelin axis influences the growth of colonic and prostatic cancer cells in vitro

BACKGROUND The risk of different cancers seems to be associated with obesity. Moreover, low ghrelin levels observed in obese people may be implicated in cancer development and progression. The aim of this study was to examine the direct effects of both forms of ghrelin (acylated and unacylated) and ghrelin receptor type 1a antagonist (D-Lys-GHRP-6) on the growth of murine colon cancer MC38 and human prostate cancer DU145 cell lines in vitro. METHODS The cells were cultured for 72 h in the presence of rat or human acylated ghrelin (rG, hG), human unacylated ghrelin (hUAG), D-Lys-GHRP-6 (GHS-RA) applied either alone or jointly. The cell line growth was assessed by the colorimetric Mosmann method. RESULTS hUAG (10(-6), 10(-7) and 10(-10) M) inhibited MC38 cancer cell growth and, at some concentrations (10(-8), 10(-9), 10(-10) M), enhanced the antineoplastic effect of GHS-RA(10(-4) M). In turn, GHS-RA evoked a biphasic effect on MC38 cancer growth: inhibitory at 10(-4) M and stimulatory at 10(-5) and 10(-6) M. Moreover, GHS-RA at the highest examined concentration (10(-4) M) enhanced the cytostatic effect of FU. Human acylated and unacylated ghrelin and GHS-RA inhibited DU145 cancer growth with moderate and different potencies. A dose-response effect was observed for the inhibitory action of hG together with the synergistic effect of hUAG and GHS-RA. CONCLUSION The obtained results indicate an involvement of the ghrelin axis in the growth regulation of colon and prostate cancers and may suggest new therapeutic options for these neoplasms.

GH-RH antagonist (MZ-4-71) inhibits VEGF secretion and proliferation of murine endothelial cells.

Angiogenesis plays a key role in solid tumor formation, invasiveness and metastasis. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen that is necessary in the process of neovascularisation. Antagonists of growth hormone-releasing hormone (GH-RH) have been shown to suppress both in vivo and in vitro growth and metastasis of many human cancer cell lines. The mechanisms that mediate the antitumorigenic actions of these antagonists involve direct and indirect pathways, but are not completely elucidated. We have examined the effect of GH-RH antagonist MZ-4-71 on proliferation activity and VEGF release from cultured murine endothelial cells HECa10 in vitro. MZ-4-71 at 10(-8) to 10(-6) M concentrations inhibited the proliferative activity of cultured cells and suppressed the release of VEGF into supernatants of 72 h endothelial cell cultures. To our knowledge this is the first study reporting antiangiogenic properties of GH-RH antagonists.

Stimulatory effect of growth hormone–releasing hormone (GHRH(1-29)NH2) on the proliferation, VEGF and chromogranin A secretion by human neuroendocrine tumor cell line NCI-H727 in vitro

Growth hormone-releasing hormone (GHRH) and its receptors have been implicated in a variety of cellular processes like cell survival, proliferation, apoptosis, angiogenesis and neoplastic transformation of various non-pituitary tissues. Here, we investigated for the first time the in vitro effect of GHRH(1-29)NH2 on the proliferation and the secretion of vascular endothelial growth factor (VEGF) and chromogranin A by the human bronchial neuroendocrine tumor cells NCI-H727. GHRH(1-29)NH2 at the concentrations of 10(-8)-10(-6)M increased the proliferation of these cells and this effect was associated with a statistically significant increase in VEGF and chromogranin A secretion into the supernatants of the tested cells. Our findings indicate that GHRH functions as a trophic hormone for bronchial neuroendocrine (NET) tumors.

Inhibition of proliferation, VEGF secretion of human neuroendocrine tumor cell line NCI-H727 by an antagonist of growth hormone-releasing hormone (GH-RH) in vitro

Growth hormone-releasing hormone (GH-RH) can stimulate not only growth hormone (GH) secretion by anterior pituitary gland but also proliferation of many cancer cell lines in vitro and in xenografts tumor models in vivo. Several antagonists of GH-RH have been shown to inhibit several cancer growths, but the role of GH-RH antagonists in the regulation of neuroendocrine cancers cell proliferation and tumor progression remains obscure. The aim of the study was to evaluate the influence of JV-1-36 (synthetic GH-RH antagonist) on proliferation and VEGF secretion by human neuroendocrine lung non-small cell carcinoma (NCI-H727) using cell culture model. The in vitro effect of JV-1-36 on the proliferation of NCI-H727 cells was assessed by the measurement of BrdU incorporation by colorimetric immunoassay. The presence of VEGF and membrane GH-RH receptors on the surface of H727 cells were visualized by immunocytochemistry using specific anti-GH-RH receptor antibody directed to the carboxy-terminal region. VEGF secretion to the cell cultures supernatants was assessed by ELISA methods. Immunoreactive cell membrane GH-RH receptors and VEGF-immunopositive cytoplasmatic granules were clearly confined on the surface of nearly all cancer cells. JV-1-36 at the concentration of 10(-6)-10(-10)M significantly inhibited growth of H727 cells, compared with untreated controls. In H727 cells, the antiproliferative JV-1-36 effect was associated with a dose-dependent reduction of VEGF secretion. In conclusion, our findings demonstrate the strong evidence for the antiproliferative action of GH-RH antagonist JV-1-36 for the NCI-H727 cells. In addition the suppression of VEGF secretion by H727 cells might contribute, at least in part, to the antitumor action of GH-RH antagonists.

Effect of growth hormone-releasing hormone (GHRH) and GHRH antagonist (MZ-4-71) on interferon-γ secretion from human peripheral blood mononuclear cells in vitro☆

Numerous reports indicate close interactions between the neuroendocrine and the immune systems. Hypothalamic neuropeptide, growth hormone-releasing hormone (GHRH) stimulates growth hormone (GH) secretion from the anterior pituitary gland, but recently some immunomodulatory properties of this peptide have also been demonstrated. In the present studies we evaluated the effect of human synthetic GHRH(1–44)NH2 and GHRH antagonist (MZ-4-71) on interferon (IFN)-γ secretion from human peripheral blood mononuclear cells (PBMC). GHRH(1–44)NH2 at 10−10, 10−8 and 10−6 M concentrations significantly (p<0.05) increased the IFN-γ level in supernatants of cultured cells, as compared with the controls. GHRH antagonist (MZ-4-71) at 10−10, 10−8 and 10−6 M concentrations diminished the IFN-γ level in supernatants in a dose-dependent manner, but statistically significant differences were observed only at 10−8 M and 10−6 M (p<0.05 vs controls). Our results demonstrate that GHRH and GHRH antagonist MZ-4-71 can modulate IFN-γ secretion in vitro by human peripheral blood mononuclear cells.

Vitamin D and thyroid cancer

The vitamin D system includes a group of fat-soluble pro-hormones and their respective metabolites. Reduced levels of vitamin D3 are linked with decrease of calcium and bone homeostasis, the onset and progression of various diseases such as autoimmune diseases, respiratory infections, diabetes mellitus type 1 and type 2, hypertension and cardiovascular disorders, and cancers (breast, colon, liver, stomach and prostate). This study aimed to investigate vitamin D metabolism by measuring 25(OH)D3, 1,25 (OH)2D3, PTH and calcium concentrations in the peripheral blood of patients with different forms of thyroid tumours.

Alteration in the serum concentrations of FGF19, FGFR4 and βKlotho in patients with thyroid cancer

HighlightsSerum concentration of FGF19 was increased in patients with thyroid cancer.Serum concentration of &bgr;Klotho was decreased in patients with thyroid cancer.FGFR4 level was increased in patients with thyroid cancer.FGFR4 and &bgr;Klotho levels positively correlated in papillary thyroid cancer group.FGF19/FGFR4/&bgr;Klotho signaling is dysregulated in patients with thyroid cancer. Introduction: &bgr;Klotho (&bgr;KL) is known to act as co‐receptor for fibroblast growth factor receptor 4 (FGFR4) which is the main cognate receptor for fibroblast growth factor 19 (FGF19). Dysregulation of this FGF19/FGFR4/&bgr;KL signaling axis has been implicated in the pathogenesis of several cancers. However, its role in the pathogenesis of thyroid cancer has not been determined. Materials and methods: The aim of this study was to assess FGF19, FGFR4 and &bgr;KL concentrations in a group of 36 patients with papillary thyroid cancer (PTC), 11 patients with follicular thyroid cancer (FTC), 9 patients with anaplastic thyroid cancer (ATC) and a group of 19 subjects with multinodular nontoxic goiter (MNG). The control group consisted of 20 healthy volunteers. Serum FGF19, FGFR4 and &bgr;KL concentrations were measured using specific ELISA methods. Results: Significantly lower concentrations of &bgr;KL and higher concentrations of FGF19 were found in patients with PTC, FTC and ATC as compared with MNG group and controls. An elevation of FGFR4 serum concentration was observed in all thyroid cancer groups in comparison to MNG group and controls; however, in FTC group it was statistically insignificant. A positive correlation was found between &bgr;KL and FGFR4 concentrations in PTC patients. The levels of &bgr;KL, FGF19 and FGFR4 did not differ significantly between MNG group and healthy controls. Conclusions: Our results indicate that a disrupted FGF19/FGFR4/&bgr;KL signaling pathway may play a role in the development of thyroid cancers. However, further studies are needed to elucidate the molecular mechanism of the neoplastic transition of thyroid epithelial cells.

Elevated Concentrations of SERPINE2/Protease Nexin-1 and Secretory Leukocyte Protease Inhibitor in the Serum of Patients with Papillary Thyroid Cancer

Introduction. SERPINE2 and secretory leukocyte protease inhibitor (SLPI) are proteins with anticoagulant properties which could promote solid tumor growth. However, their role in the pathogenesis of thyroid cancer has not been determined. Materials and Methods. The aim of this study was to assess serum SERPINE2 and SLPI concentrations in a group of 36 patients with papillary thyroid cancer (PTC) and a group of 19 subjects with multinodular nontoxic goiter (MNG). The control group (CG) consisted of 20 healthy volunteers. Blood samples were collected one day before surgery. Serum SERPINE2 and SLPI concentrations were measured using specific ELISA methods. Results. Significantly higher concentrations of SERPINE2 and SLPI were found in patients with PTC as compared with MNG and controls. Positive correlation was found between SERPINE2 and SLPI concentrations in PTC patients. The levels of SERPINE2 and SLPI did not differ significantly between MNG and healthy controls. Conclusions. Our results indicate that SERPINE2 and SLPI play a significant role in the development of papillary thyroid cancer and imply that the evaluation of serum concentrations of both anticoagulant molecules may be considered as additional marker for the differentiation of malignancies during the preoperative diagnosis of patients with thyroid gland tumors.