Objectives: Vapreotide, a synthetic analog of somatostatin, has analgesic activity most likely mediated through the blockade of neurokinin-1 receptor (NK1R), the substance P (SP)-preferring receptor. The ability of vapreotide to interfere with other biological effects of SP has yet to be investigated.
Methods: We studied the ability of vapreotide to antagonize NK1R in three different cell types: immortalized U373MG human astrocytoma cells, human monocyte-derived macrophages (MDM) and a human embryonic kidney cell line, HEK293. Both U373MG and MDM express endogenous NK1R while HEK293 cells, which normally do not express NK1R, are stably transformed to express human NK1R (HEK293-NK1R).
Results: Vapreotide attenuates SP-triggered intracellular calcium increases and nuclear factor-κB activation in a dose-dependent manner. Vapreotide also inhibits SP-induced interleukin-8 and monocyte chemotactic protein-1 production in HEK293-NK1R and U373MG cell lines. Vapreotide inhibits HIV-1 infection of human MDM in vitro, an effect that is reversible by SP pretreatment.
Conclusions: Our findings indicate that vapreotide has NK1R antagonist activity and may have a potential application as a therapeutic intervention in HIV-1 infection.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3839635 | PMC |
http://dx.doi.org/10.1159/000350468 | DOI Listing |
Cancers (Basel)
January 2025
The Brown Foundation Institute of Molecular Medicine, McGovern Medical School, The University of Texas Health Science Center, Houston, TX 77054, USA.
Background: While the clinical use of radiolabeled somatostatin analogs is well established in neuroendocrine tumors, there is growing interest in expanding their application to other somatostatin receptor 2 (SSTR2)-expressing cancers. This study investigates the potential utility of SSTR2-targeted theranostics in hepatocellular carcinoma (HCC).
Methods: SSTR2 expression in HCC cell lines and clinical samples was evaluated using qRT-PCR, Western blot analysis, and a public dataset.
Front Oncol
January 2025
Department of Nuclear Medicine, Mount Sinai Hospital at Icahn School of Medicine, New York, NY, United States.
Peptide receptor radionuclide therapy (PRRT) is used for the management of neuroendocrine tumors (NETs) not responsive to somatostatin analogs. In this case series, we report two patients with pancreatic vasoactive intestinal peptide (VIP)-secreting NETs (VIPomas) not responsive to any other therapies who achieved symptomatic control and a significant decrease in serum VIP levels with PRRT during their hospital stay. Two patients with VIPomas were admitted to the hospital with multiple prior hospital admissions after going through multiple lines of therapy.
View Article and Find Full Text PDFCurr Treat Options Oncol
January 2025
The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins and Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA.
Treatment for neuroendocrine neoplasms (NENs) is tailored to the tumor's site of origin, grade, and differentiation. NENs are categorized into two main types: well-differentiated neuroendocrine tumors (NETs), which tend to grow more slowly and are less aggressive, and poorly differentiated neuroendocrine carcinomas (NECs), which are highly aggressive and harder to treat. Treatment options for NETs range from somatostatin analogues and mTOR inhibitors to peptide receptor radionuclide therapy (PRRT) with Lutetium-177 dotatate.
View Article and Find Full Text PDFEndocr J
January 2025
Department of Molecular Diagnosis, Chiba University Graduate school of Medicine, Chiba 260-8670, Japan.
Pasireotide (PAS), a multireceptor somatostatin analog, has been demonstrated to effectively control hormone levels, including those of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), in patients with acromegaly. However, it induces hyperglycemia by inhibiting insulin secretion via somatostatin receptor 5 (SSTR5). Despite the extensive literature on the occurrence of PAS-induced hyperglycemia, there is still no consensus on the optimal first-line treatment for this complication.
View Article and Find Full Text PDFRev Endocr Metab Disord
January 2025
Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL, USA.
This review focuses on our current understanding of how growth hormone releasing hormone (GHRH): 1) stimulates GH release and synthesis from pituitary growth hormone (GH)-producing cells (somatotropes), 2) drives somatotrope proliferation, 3) is negatively regulated by somatostatin (SST), GH and IGF1, 4) is altered throughout lifespan and in response to metabolic challenges, and 5) analogues can be used clinically to treat conditions of GH excess or deficiency. Although a large body of early work provides an underpinning for our current understanding of GHRH, this review specifically highlights more recent work that was made possible by state-of-the-art analytical tools, receptor-specific agonists and antagonists, high-resolution in vivo and ex vivo imaging and the development of tissue (cell) -specific ablation mouse models, to paint a more detailed picture of the regulation and actions of GHRH.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!