Siglec-15, a Siglec family member and type-1 transmembrane protein, is expressed mainly in human macrophages and dendritic cells. It is comprised of a lysine-containing transmembrane domain, two extracellular immunoglobulin (Ig)-like domains and a short cytoplasmic domain. Siglec-15 is highly conserved in vertebrates and acts as an immunoreceptor. It exerts diverse functions on osteoclast physiology as well as the tumor microenvironment. Siglec-15 interacts with adapter protein DAP12 - Syk signaling pathway to regulate the RANKL/RANK-mediated PI3K, AKT, and ERK signaling pathways during osteoclast formation in vitro. Consistently, the lack of the Siglec-15 gene in mice leads to impaired osteoclast activity and osteopetrosis in vivo. In addition, Siglec-15 is expressed by tumor-associated macrophages (TAMs) and regulates the tumor microenvironment by activating the SYK/MAPK signaling pathway. Interestingly, Siglec-15 shares sequence homology to programmed death-ligand 1 (PD-L1) and has a potential immune-regulatory role in cancer immunology. Thus, Siglec-15 might also represent an alternative target for the treatment of cancers that do not respond to anti-PD-L1/PD-1 immunotherapy. Understanding the role of Siglec-15 in osteoclastogenesis and the tumor microenvironment will help us to develop new treatments for bone disorders and cancer.
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http://dx.doi.org/10.1002/jcp.30654 | DOI Listing |
Head Neck
January 2025
Department of Pathology, All India Institute of Medical Sciences, Rishikesh, India.
Background: To correlate between immunohistochemical expression of tumor-infiltrating lymphocytes (TILs), tumor-associated macrophages (TAMs), and natural killer (NK) cells with the AJCC 8th edition TNM staging system and other disease-modifying clinico-pathological variables.
Methods: The representative histology sections of tumor invasive margin (IM) and tumor core (TC) were selected according to the International Immuno-Oncology Biomarker Working Group and were subjected to immunohistochemistry with antibodies for TILs (CD3, CD8, FOXP3), NK Cells (CD57), TAMs (CD68, CD163) and pan-leukocyte marker (CD45). Histo-immuno-density-intensity (HIDI) scoring was calculated as a product of the proportion and intensity of staining.
J Exp Clin Cancer Res
January 2025
Beijing Neurosurgical Institute, Capital Medical University, Beijing, 100070, China.
Background: Bone-invasive Pituitary Neuroendocrine Tumors (BI PitNETs) epitomize an aggressive subtype of pituitary tumors characterized by bone invasion, culminating in extensive skull base bone destruction and fragmentation. This infiltration poses a significant surgical risk due to potential damage to vital nerves and arteries. However, the mechanisms underlying bone invasion caused by PitNETs remain elusive, and effective interventions for PitNET-induced bone invasion are lacking in clinical practice.
View Article and Find Full Text PDFCell Death Dis
January 2025
Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.
Prostate cancer is a heterogeneous disease with a slow progression and a highly variable clinical outcome. The tumor suppressor genes PTEN and TP53 are frequently mutated in prostate cancer and are predictive of early metastatic dissemination and unfavorable patient outcomes. The progression of solid tumors to metastasis is often associated with increased cell plasticity, but the complex events underlying TP53-loss-induced disease aggressiveness remain incompletely understood.
View Article and Find Full Text PDFBiochemistry (Mosc)
December 2024
Medicinal Chemistry Center, Togliatti State University, Togliatti, 445020, Russia.
Human carbonic anhydrase IX (CAIX) plays a key role in maintaining pH homeostasis of malignant neoplasms, thus creating a favorable microenvironment for the growth, invasion, and metastasis of tumor cells. Recent studies have established that inhibition of CAIX expressed on the surface of tumor cells significantly increases the efficacy of classical chemotherapeutic agents and makes it possible to suppress the resistance of tumor cells to chemotherapy, as well as to increase their sensitivity to drugs (in particular, to reduce the required dose of cytostatic agents). In this work, we studied the ability of new CAIX inhibitors based on substituted 1,2,4-oxadiazole-containing primary aromatic sulfonamides, to potentiate the cytostatic effect of gefitinib (selective inhibitor of epidermal growth factor receptor tyrosine kinase domain) under hypoxic conditions.
View Article and Find Full Text PDFInt Rev Cell Mol Biol
January 2025
Tumor Immunology and Immunotherapy Unit, IRCCS-Regina Elena National Cancer Institute, Rome, Italy. Electronic address:
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