Versican maintains the homeostasis of adipose tissues and regulates energy metabolism.

Versican is a large chondroitin sulfate proteoglycan in the extracellular matrix. It plays a pivotal role in the formation of the provisional matrix. S100a4, previously known as fibroblast-specific protein, functions as a calcium channel-binding protein. To investigate the role of versican expressed in fibroblasts, we generated conditional knockout mice in which versican expression is deleted in cells expressing S100a4. We found that S100a4 is expressed in adipose tissues, and these mice exhibit obesity under a normal diet, which becomes apparent as early as five months. The white adipose tissues of these mice exhibited decreased expression levels of S100a4 and versican and hypertrophy of adipocytes. qRT-PCR showed a reduced level of UCP1 in their white adipose tissues, indicating that the basic energy metabolism is diminished. These results suggest that versican in adipose tissues maintains the homeostasis of adipose tissues and regulates energy metabolism.

Claudin-18.2 mediated interaction of gastric Cancer cells and Cancer-associated fibroblasts drives tumor progression.

BACKGROUND: Claudin-18.2 (CLDN18.2) has emerged as an alluring therapeutic target against gastrointestinal tumors in recent years. However, a thorough understanding of its regulatory mechanism in gastric cancer remains elusive. METHODS: We presented a comprehensive study comprising 185 gastric cancer patients, which included 112 cases with high CLDN18.2 expression and 73 cases with low CLDN18.2 expression as determined by immunohistochemistry. After overdressed CLDN18.2 in AGS and NUGC4 cell lines, we elucidated the functions of CLDN18.2 in connecting gastric cancer cells and cancer-associated fibroblasts (CAFs) through an in vitro adhesion models and in vivo lung colonization models. The molecular mechanism underlying CLDN18.2-mediated interaction between gastric cancer cells and CAFs was identified through RNA sequencing and protein-proximity labeling techniques in vivo. RESULTS: In our own cohort, a correlation was observed between high levels of CLDN18.2 expression and advanced cancer stage, poor prognosis, and heightened infiltration of CAFs. We elucidated a pivotal role of CLDN18.2 in mediating adhesion between gastric cancer cells and CAFs, which leads to the adhesion of cancer cells to stroma tissue and facilitates the clustering of cancer cells and CAFs into embolus, enhancing gastric cancer's metastatic progression and the risk of embolic death. Mechanistically, it was discovered that CAFs can activate adhesion and metastasis-related signaling pathways in CLDN18.2-positive gastric cancer cells. Furthermore, using an in vivo protein-proximity labeling approach, we identified S100 calcium binding protein A4 (S100A4) as a distinctive marker of CAFs that interacts with CLDN18.2 to enhance gastric cancer progression. CONCLUSIONS: Our findings illuminated the role of the CLDN18.2-mediated interaction between cancer cells and CAFs in promoting gastric cancer progression and embolism, thereby providing insight into potential therapeutic avenues for CLDN18.2 positive cancers. Video Abstract.

Long noncoding RNA VPS9D1-AS1 promotes the progression of endometrial cancer via regulation of the miR-187-3p/S100A4 axis.

VPS9D1-AS1 functions as an oncogene in many cancers. However, its role and potential mechanism in the progression of endometrial cancer (EC) are not fully understood. VPS9D1-AS1 levels in EC and adjacent normal tissues were investigated using the TCGA-UCEC cohort and 24 paired clinical samples. The roles of VPS9D1-AS1 and miR-187-3p in cell cycle, proliferation, and apoptosis were evaluated by loss- and gain-of-function experiments. In addition, the effect of VPS9D1-AS1 on tumor growth was further investigated in vivo. Rescue experiments were performed to investigate the involvement of the miR-187-3p/S100A4 axis in VPS9D1-AS1 knockdown-mediated antitumor effects. VPS9D1-AS1 was highly expressed in EC tissues. VPS9D1-AS1 knockdown, similar to miR-187-3p overexpression, significantly inhibited cell proliferation, inhibited colony formation, induced cell cycle arrest, and facilitated apoptosis of KLE cells. MiR-187-3p bound directly to VPS9D1-AS1 and the 3'UTR of S100A4. Furthermore, VPS9D1-AS1 negatively regulated miR-187-3p while positively regulating S100A4 expression in EC cells. MiR-187-3p knockdown or S100A4 overexpression partially reversed the tumor suppressive function of VPS9D1-AS1 knockdown. The results suggest that VPS9D1-AS1 affects EC progression by regulating the miR-187-3p/S100A4 axis. This may provide a promising therapeutic target to help treat EC.

Mts1 (S100A4) and Its Peptide Demonstrate Cytotoxic Activity in Complex with Tag7 (PGLYRP1) Peptide.

Receptors of cytokines are major regulators of the immune response. In this work, we have discovered two new ligands that can activate the TNFR1 (tumor necrosis factor receptor 1) receptor. Earlier, we found that the peptide of the Tag (PGLYRP1) protein designated 17.1 can interact with the TNFR1 receptor. Here, we have found that the Mts1 (S100A4) protein interacts with this peptide with a high affinity (Kd = 1.28 × 10-8 M), and that this complex is cytotoxic to cancer cells that have the TNFR1 receptor on their surface. This complex induces both apoptosis and necroptosis in cancer cells with the involvement of mitochondria and lysosomes in cell death signal transduction. Moreover, we have succeeded in locating the Mts1 fragment that is responsible for protein-peptide interaction, which highly specifically interacts with the Tag7 protein (Kd = 2.96 nM). The isolated Mts1 peptide M7 also forms a complex with 17.1, and this peptide-peptide complex also induces the TNFR1 receptor-dependent cell death. Molecular docking and molecular dynamics experiments show the amino acids involved in peptide binding and that may be used for peptidomimetics' development. Thus, two new cytotoxic complexes were created that were able to induce the death of tumor cells via the TNFR1 receptor. These results may be used in therapy for both cancer and autoimmune diseases.

S100A4 modulates cell proliferation, apoptosis and fibrosis in the hyperplastic prostate.

Benign prostatic hyperplasia (BPH) is one of the most common diseases in elderly men worldwide that may result in lower urinary tract symptoms (LUTS). At present, the specific pathophysiological mechanism for BPH/LUTS LUTS remains unclear. S100 calcium binding protein A4 (S100A4), a member of the calcium binding protein family, regulates a variety of biological processes including cell proliferation, apoptosis and fibrosis. The aim of the current study was to explore and clarify the possible role of S100A4 in BPH/LUTS. The human prostate stromal cell line (WPMY-1), rat prostate epithelial cells, human prostate tissues and two BPH rat models were employed in this study. The expression and localization of S100A4 were detected by quantitative real time PCR (qRT-PCR), immunofluorescence microscopy, Western blotting and immunohistochemistry analysis. Also, S100A4 knockdown or overexpression cell models were constructed and a BPH rat model was induced with testosterone propionate (T) or phenylephrine (PE). The BPH animals were treated with Niclosamide, a S100A4 transcription inhibitor. Results demonstrated that S100A4 was mainly localized in human prostatic stroma and rat prostatic epithelium, and showed a higher expression in BPH. Knockdown of S100A4 induced cell apoptosis, cell proliferation arrest and a reduction of tissue fibrosis markers. Overexpression of S100A4 reversed the aforementioned changes. We also demonstrated that S100A4 regulated proliferation and apoptosis mainly through the ERK pathway and modulated fibrosis via Wnt/ß-catenin signaling. In conclusion, our novel data demonstrate that S100A4 could play a crucial role in BPH development and may be explored as a new therapeutic target of BPH.

S100A4 a classical DAMP as a therapeutic target in fibrosis.

Fibrosis regardless of aetiology is characterised by persistently activated myofibroblasts that are contractile and secrete excessive amounts of extracellular matrix molecules that leads to loss of organ function. Damage-Associated Molecular Patterns (DAMPs) are endogenous host-derived molecules that are released from cells dying or under stress that can be triggered by a variety of insults, either chemical or physical, leading to an inflammatory response. Among these DAMPs is S100A4, part of the S100 family of calcium binding proteins that participate in a variety of cellular processes. S100A4 was first described in context of cancer as a pro-metastatic factor. It is now appreciated that aside from its role in cancer promotion, S100A4 is intimately involved in tissue fibrosis. The extracellular form of S100A4 exerts its effects through multiple receptors including Toll-Like Receptor 4 and RAGE to evoke signalling cascades involving downstream mediators facilitating extracellular matrix deposition and myofibroblast generation and can play a role in persistent activation of myofibroblasts. S100A4 may be best understood as an amplifier of inflammatory and fibrotic processes. S100A4 appears critical in systemic sclerosis pathogenesis and blocking the extracellular form of S100A4 in vivo in various animal models of disease mitigates fibrosis and may even reverse established disease. This review appraises S100A4's position as a DAMP and its role in fibrotic conditions and highlight therapeutically targeting this protein to halt fibrosis, suggesting that it is a tractable target.

A mucosal vaccine formulation against tuberculosis by exploiting the adjuvant activity of S100A4-A damage-associated molecular pattern molecule.

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), remains one of the top three causes of death. Currently, the only licensed vaccine against TB is the bacillus Calmette-Guerin (BCG), which lacks efficacy in preventing and controlling pulmonary TB in adults. We aimed to evaluate a nasal TB vaccine formulation composed of the Mtb-specific vaccine antigen ESAT-6, an Mtb-associated protein that can trigger protective immune responses, and S100A4, a recently characterized novel mucosal adjuvant. Mice were intranasally given recombinant ESAT-6 in the presence or absence of S100A4 as an adjuvant. We have provided experimental evidence demonstrating that S100A4 admixed to ESAT-6 could induce Mtb-specific adaptive immune responses after intranasal immunization. S100A4 remarkably augmented the levels of anti-ESAT-6 IgG in serum and IgA in mucosal sites, including lung exudates, bronchoalveolar lavage fluid (BALF) and nasal lavage. Furthermore, in both lung and spleen tissues, S100A4 strongly promoted ESAT-6-specific expansion of CD4 T cells. Both CD4 and CD8 T cells from these tissues expressed increased levels of IFN-γ, TNF-α, and IL-17, cytokines critical for antimicrobial activity. Antigen-reencounter-induced T cell proliferative responses, a key vaccine performance indicator, were augmented in the spleen of S100A4-adjuvanted mice. Furthermore, CD8 T cells from the spleen and lung tissues of these mice expressed higher levels of granzyme B upon antigen re-stimulation. S100A4-adjuvanted immunization may predict good mucosal protection against TB.

S100A4 Is a Key Facilitator of Thoracic Aortic Dissection.

Background: Thoracic aortic dissection (TAD) is one of the cardiovascular diseases with high incidence and fatality rates. Vascular smooth muscle cells (VSMCs) play a vital role in TAD formation. Recent studies have shown that extracellular S100A4 may participate in VSMCs regulation. However, the mechanism(s) underlying this association remains elusive. Consequently, this study investigated the role of S100A4 in VSMCs regulation and TAD formation. Methods: Hub genes were screened based on the transcriptome data of aortic dissection in the Gene Expression Synthesis database. Three-week-old male S100A4 overexpression (AAV9- S100A4 OE) and S100A4 knockdown (AAV9- S100A4 KD) mice were exposed to ß-aminopropionitrile monofumarate through drinking water for 28 days to create the murine TAD model. Results: S100A4 was observed to be the hub gene in aortic dissection. Furthermore, overexpression of S100A4 was exacerbated, whereas inhibition of S100A4 significantly improved TAD progression. In the TAD model, the S100A4 was observed to aggravate the phenotypic transition of VSMCs. Additionally, lysyl oxidase (LOX) was an important target of S100A4 in TAD. S100A4 interacted with LOX in VSMCs, reduced mature LOX (m-LOX), and decreased elastic fiber deposition, thereby disrupting extracellular matrix homeostasis and promoting TAD development. Elastic fiber deposition in human aortic tissues was negatively correlated with the expression of S100A4, which in turn, was negatively correlated with LOX. Conclusions: Our data showed that S100A4 modulates TADprogression, induces lysosomal degradation of m-LOX, and reduces the deposition of elastic fibers by interacting with LOX, thus contributing to the disruption of extracellular matrix homeostasis in TAD. These findings suggest that S100A4 may be a new target for the prevention and treatment of TAD.

Evaluation of Extracellular Matrix Remodeling in Full-thickness Skin Grafts in Mice.

Abdominal hernia is a protruding weakness in the abdominal wall. It affects abdominal strength and life quality and can lead to complications due to intestinal entrapment. Autologous full-thickness skin graft (FTSG) has recently become an alternative material for reinforcement in the surgical repair of large abdominal hernias instead of synthetic mesh. FTSG eventually integrates with the abdominal wall, but the long-term fate of the graft itself is not fully understood. This has implications as to how these grafts should be optimally used and handled intraoperatively. This study investigates the remodeling of FTSG in either the onlay or the intraperitoneal position 8 weeks after FTSG transplantation in an experimental mouse model. There was a significant presence of fibroblasts, indicated by vimentin and S100A4 staining, but there were significant variations among animals as to how much of the graft had been remodeled into dense connective tissue. This correlated significantly with the proportion of vimentin-positive cells in the dense connective tissue. We also found that collagen hybridizing peptide staining intensity, a marker of active remodeling, was significantly associated with the proportion of S100A4-positive cells in the dense connective tissue of the FTSG.

GnRH-mediated suppression of S100A4 expression inhibits endometrial epithelial cell proliferation in sheep via GNAI2/MAPK signaling.

Background: Gonadotrophin-releasing hormone (GnRH) administration significantly decreases the pregnancy rate of recipient ewes after embryo transfer, possibly because GnRH affects endometrial epithelial cell function. Therefore, this study investigated the effect of GnRH on endometrial epithelial cells. Methods: Transcriptome sequencing was used to determine the regulatory effect of GnRH on the ewe endometrium, and the S100A4 gene, which showed altered transcription, was screened as a candidate regulator of this effect. Endometrial epithelial cells were further isolated, the S100A4 protein was immunoprecipitated, and host proteins that interacted with S100A4 were identified by mass spectrometry. We further verified the effects of S100A4 and GNAI2 on the proliferation of endometrial epithelial cells via overexpression/knockdown experiments and subsequent CCK-8 and EdU assays. The effect of S100A4 deletion in endometrial cells on reproduction was verified in mice with S100A4 knockout. Results: Our results showed that S100A4 gene transcription in endometrial cells was significantly inhibited after GnRH administration. GNAI2 was identified as a downstream interacting protein of S100A4, and S100A4 was confirmed to activate the MAPK signaling pathway to promote cell proliferation by targeting GNAI2. Conclusion: GnRH can suppress the expression of S100A4 in the endometrium, consequently inhibiting the proliferation of endometrial cells through the S100A4/GNAI2/MAPK signaling pathway. These findings suggest a potential explanation for the limited efficacy of GnRH in promoting embryo implantation.

Immunocompetent mouse models revealed that S100A4+ monocytes/macrophages facilitate long-term Zika virus infection in the testes.

During its global epidemic, Zika virus (ZIKV) attracted widespread attention due to its link with various severe neurological symptoms and potential harm to male fertility. However, the understanding of how ZIKV invades and persists in the male reproductive system is limited due to the lack of immunocompetent small animal models. In this study, immunocompetent murine models were generated by using anti-IFNAR antibody blocked C57BL/6 male mice and human STAT2 (hSTAT2) knock in (KI) male mice. After infection, viral RNA could persist in the testes even after the disappearance of viremia. We also found a population of ZIKV-susceptible S100A4+ monocytes/macrophages that were recruited into testes from peripheral blood and played a crucial role for ZIKV infection in the testis. By using single-cell RNA sequencing, we also proved that S100A4+ monocytes/macrophages had a great impact on the microenvironment of ZIKV-infected testes, thus promoting ZIKV-induced testicular lesions. In conclusion, this study proposed a novel mechanism of long-term ZIKV infection in the male reproductive system.

S100A4 reprofiles lipid metabolism in mast cells via RAGE and PPAR-γ signaling pathway.

S100A4 is implicated in metabolic reprogramming across various cell types and is known to propel the progression of numerous diseases including allergies. Nonetheless, the influence of S100A4 on mast cell metabolic reprogramming during allergic disorders remains unexplored. Utilizing a mast cell line (C57), cells were treated with recombinant mouse S100A4 protein, with or without a PPAR-γ agonist (ROSI) or a RAGE inhibitor (FPS-ZM1). Subsequent assessments were conducted for mast cell activation and lipid metabolism. S100A4 induced mast cell activation and the release of inflammatory mediators, concurrently altering molecules involved in lipid metabolism and glycolysis over time. Furthermore, S100A4 stimulation resulted in cellular oxidative stress and mitochondrial dysfunction. Alterations in the levels of pivotal molecules within the RAGE/Src/JAK2/STAT3/PPAR-γ and NF-κB signaling pathways were noted during this stimulation, which were partially counteracted by ROSI or FPS-ZMI. Additionally, a trend of metabolic alterations was identified in patients with allergic asthma who exhibited elevated serum S100A4 levels. Correlation analysis unveiled a positive association between serum S100A4 and serum IgE, implying an indirect association with asthma. Collectively, our findings suggest that S100A4 regulates the lipid-metabolic reprogramming of mast cells, potentially via the RAGE and PPAR-γ-involved signaling pathway, offering a novel perspective in the disease management in patients with allergic disorders.

Recognition of granulocyte-macrophage colony-stimulating factor by specific S100 proteins.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic myelopoietic growth factor and proinflammatory cytokine, clinically used for multiple indications and serving as a promising target for treatment of many disorders, including cancer, multiple sclerosis, rheumatoid arthritis, psoriasis, asthma, COVID-19. We have previously shown that dimeric Ca2+-bound forms of S100A6 and S100P proteins, members of the multifunctional S100 protein family, are specific to GM-CSF. To probe selectivity of these interactions, the affinity of recombinant human GM-CSF to dimeric Ca2+-loaded forms of 18 recombinant human S100 proteins was studied by surface plasmon resonance spectroscopy. Of them, only S100A4 protein specifically binds to GM-CSF with equilibrium dissociation constant, Kd, values of 0.3-2 µM, as confirmed by intrinsic fluorescence and chemical crosslinking data. Calcium removal prevents S100A4 binding to GM-CSF, whereas monomerization of S100A4/A6/P proteins disrupts S100A4/A6 interaction with GM-CSF and induces a slight decrease in S100P affinity for GM-CSF. Structural modelling indicates the presence in the GM-CSF molecule of a conserved S100A4/A6/P-binding site, consisting of the residues from its termini, helices I and III, some of which are involved in the interaction with GM-CSF receptors. The predicted involvement of the 'hinge' region and F89 residue of S100P in GM-CSF recognition was confirmed by mutagenesis. Examination of S100A4/A6/P ability to affect GM-CSF signaling showed that S100A4/A6 inhibit GM-CSF-induced suppression of viability of monocytic THP-1 cells. The ability of the S100 proteins to modulate GM-CSF activity is relevant to progression of various neoplasms and other diseases, according to bioinformatics analysis. The direct regulation of GM-CSF signaling by extracellular forms of the S100 proteins should be taken into account in the clinical use of GM-CSF and development of the therapeutic interventions targeting GM-CSF or its receptors.

Immunolocalización de s100a4 y α-sma en tejidos gingivales de pacientes con hipertrofia gingival por tratamiento ortodóntico: estudio preliminar / Immunolocalization of s100a4 and α-sma in gingival tissues of patients with gingival hypertrophy due to orthodontic treatment: preliminary study

Objective: to determine the presence and distribution of markers of the epithelialmesenchymal transition (EMT) (S-100A4 and alpha-smooth muscle actin-α-SMA) in gingival tissues of patients affected by Gingival hypertrophy (GH) due to orthodontics.GH is an exaggerated increase in gingival tissue whose pathogenesis is unknown. However, it has been reported that the epithelial-mesenchymal transition as a process involved in other types of GH. Materials and methods: descriptive study that included the analysis of gingival tissues of healthy individuals (n = 6) and patients with GH by orthodontic treatment (n = 6). Before gingival surgery, the patients underwent a periodontal hygiene phase. The gingival tissue samples obtained were processed and embedded in paraffin. The cuts were made with a microtome and deposited on polysine adhesion slides. Histological hematoxylin-eosin staining was performed.The identification and location of S-100A4 and α-SMA markers was determined by immunohistochemistry with monoclonal antibodies. The reading of the findings was carried out by oral pathologists. Results: in healthy individuals, an S100A4 label was observed in Langerhans cells, while α-SMA was identified in the vascular endothelium of all samples analysed. However, in patients with GH due to orthodontics, they registered an intense staining of S100A4 in gingival fibroblasts, Langerhans cells, vascular endothelium, and areas adjacent to the rupture of blood vessel. α-SMA expression in GO was detected in the vascular endothelium and gingival fibroblasts. Conclusion: the differential immunostaining of EMT markers in gingival tissues of patients with orthodontic GH suggests an eventual role of EMT in the pathogenesis of this pathology..Au

Objective: to determine the presence and distribution of markers of the epithelialmesenchymal transition (EMT) (S-100A4 and alpha-smooth muscle actin-α-SMA) in gingival tissues of patients affected by Gingival hypertrophy (GH) due to orthodontics. GH is an exaggerated increase in gingival tissue whose pathogenesis is unknown. However, it has been reported that the epithelial-mesenchymal transition as a process involved in other types of GH. Materials and methods: descriptive study that included the analysis of gingival tissues of healthy individuals (n = 6) and patients with GH by orthodontic treatment (n = 6). Before gingival surgery, the patients underwent a periodontal hygiene phase. The gingival tissue samples obtained were processed and embedded in paraffin. The cuts were made with a microtome and deposited on polysine adhesion slides. Histological hematoxylin-eosin staining was performed. The identification and location of S-100A4 and α-SMA markers was determined by immunohistochemistry with monoclonal antibodies. The reading of the findings was carried out by oral pathologists. Results: in healthy individuals, an S100A4 label was observed in Langerhans cells, while α-SMA was identified in the vascular endothelium of all samples analysed. However, in patients with GH due to orthodontics, they registered an intense staining of S100A4 in gingival fibroblasts, Langerhans cells, vascular endothelium, and areas adjacent to the rupture of blood vessel. α-SMA expression in GO was detected in the vascular endothelium and gingival fibroblasts. Conclusion: the differential immunostaining of EMT markers in gingival tissues of patients with orthodontic GH suggests an eventual role of EMT in the pathogenesis of this pathology..Au

Benzyl isothiocyanate inhibits invasion and induces apoptosis via reducing S100A4 expression and increases PUMA expression in oral squamous cell carcinoma cells

Benzyl isothiocyanate (BITC) has been shown to inhibit invasion and induce apoptosis of various types of cancer. However, its role on human oral squamous cell carcinoma (OSCC) cells is still not well elucidated. In the present study, we investigated the effect of BITC on apoptosis and invasion of SCC9 cells, and its underlying mechanisms in vitro and in vivo. SCC9 cells were exposed to BITC (5 and 25 μM) for 24 and 48 h. Cell growth, apoptosis, invasion, and migration were detected in vitro by MTT, FITC-conjugated annexin V/propidium iodide staining followed by flow cytometry, Matrigel-coated semi-permeable modified Boyden, and wound-healing assay. S100A4, PUMA, and MMP-9 expressions were detected to investigate its mechanisms. Xenotransplantation experiments were used to investigate the role of BITC on tumor growth and lung metastasis. BITC inhibited cell viability and induced cell apoptosis in a dose- and time-dependent manner through upregulation of PUMA signals. BITC inhibited cell invasion and migration by downregulation of S100A4 dependent MMP-9 signals. The ip administration of BITC reduced tumor growth but not lung metastasis of SCC9 cells subcutaneously implanted in nude mice. BITC treatment activated pro-apoptotic PUMA and inhibited S100A4-dependent MMP-9 signals, resulting in the inhibition of cell growth and invasion in cultured and xenografted SCC9 cells. Thereby, BITC is a potential therapeutic approach for OSCC.

Superexpressão do receptor de Inositol 1,4, 5-trifosfato isoforma 3 (ITPR3) em colangiocarcinoma e sua correlação com a proteína dependente de cálcio S100A4 / Inositol 1,4, 5-triphosphate receptor isoform 3 (ITPR3) overexpression in cholangiocarcinoma and its correlation with calcium-dependent protein S100A4

O colangiocarcinoma (CCA) é a segunda neoplasia mais maligna do fígado que surge na árvore biliar. O CCA está associado com mau prognóstico e os principais fatores envolvidos em sua patogênese não são bem compreendidos. Os receptores tirosina quinases (RTKs), como o receptor do fator de crescimento epidérmico (EGFR), podem mediar as vias de sinalização de cálcio intracelular (Ca 2+ ), via inositol 1,4,5-trifosfato (InsP3). Eles ativam os receptores 1,4,5-trifosfato (ITPRs) e regulam o crescimento tumoral. ITPR isoforma 3 é o principal canal de liberação intracelular de Ca 2+ em colangiócitos. Os efeitos do Ca 2+ intracelular, por sua vez são mediados por proteínas de ligação de cálcio, como calmodulina e proteína A4 de ligação de cálcio S100 (S100A4). No entanto, o significado clínico patológico e biológico de EGFR, ITPR3 e S100A4 no CCA permanece obscuro. Assim, o presente trabalho investiga a imuno exprepressão dessas três proteínas em 59 pacientes diagnosticados com CCA, submetidos a tratamento cirúrgico curativo e correlaciona os dados com características clínico-patológicas e sobrevida. A alta expressão de ITPR3 foi correlacionada com os níveis de CA 19-9, estágio TNM e metástases em linfonodos (N). Além disso, a expressão de ITPR3 foi aumentada em CCA distal em comparação com ductos biliares de controle e CCAs intra-hepáticos e peri-hilares. Os escores clínicos ITPR3 e S100A4 foram significativamente correlacionados. Em resumo, a super expressão de ITPR3 pode contribuir para a progressão da CCA e pode representar um potencial alvo terapêutico. Palavras-chave: ITPRs; ITPR3; S100A4; Colangiocarcinoma; Fígado; Câncer

Cholangiocarcinoma (CCA) is the second most malignant neoplasm in the liver that arises from the biliary tree. CCA is associated with a poor prognosis, and the key players involved in its pathogenesis are still not well understood. Receptor tyrosine kinases (RTKs), such as epidermal growth factor receptor (EGFR), can mediate intracellular calcium (Ca2+) signaling pathways via inositol 1,4,5trisphosphate (InsP3), activating inositol 1,4,5-trisphosphate receptors (ITPRs) and regulating tumor growth. ITPR isoform 3 (ITPR3) is the main intracellular Ca2+ release channel in cholangiocytes. The effects of intracellular Ca2+ are mediated by calciumbinding proteins such as Calmodulin and S100 calcium-binding protein A4 (S100A4). However, the clinicopathological and biological significance of EGFR, ITPR3 and S100A4 in CCA remains unclear. Thus, the present work investigates the immunoexpression of these three proteins in 59 CCAs from patients who underwent curative surgical treatment and correlates the data with clinicopathological features and survival. High ITPR3 expression was correlated with CA 19-9 levels, TNM stage and lymph node metastasis (N). Furthermore, ITPR3 expression was increased in distal CCA compared to control bile ducts and intrahepatic and perihilar CCAs. In summary, ITPR3 overexpression could contribute to CCA progression and it may represent a potential therapeutic target.