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Background: It has been recognized that the gonadotropin-releasing hormone antagonist (GnRH-ant) protocol has a detrimental effect on clinical outcomes compared to the GnRH agonist (GnRH-a) protocol during in vitro fertilization-fresh embryo transfer (IVF-ET) cycles. However, the related mechanisms were unclear. Methods: A total of 18,561 patients, who underwent fresh IVF-ET cycles in the Center for Assisted Reproduction of Jiangxi Maternal and Child Health Hospital from January 2014 to September 2021, were retrospectively analyzed. The propensity score matching (PSM) technique was used to control for confounding factors between the GnRH-ant and GnRH-a groups. Human endometrial stromal cells (hESCs) were collected for primary culture and treated with relevant receptor antagonists and activators. RT-PCR, Western Blot, immunofluorescence staining, cell migration and adhesion assays, and animal experiments were employed to elucidate the molecular mechanism by which GnRH antagonist affects the migration and adhesion ability of hESCs. Results: There was no statistical difference between the two groups in terms of baseline characteristics after matching basal status by propensity score matching. The result showed that the endometrial thickness (10.4 ± 2.35 vs. 11.03 ± 2.61 mm, p <.001) on trigger day was significantly lower in the GnRH-ant group. Compared with the GnRH-a protocol, the implantation rate (39.71% vs. 50.36%, p <.001), biochemical pregnancy rate (64.26% vs. 72.7%, p <.001), clinical pregnancy rate (56.39% vs. 65.24%, p <.001), live birth rate (45.25% vs. 56.1%, p <.001) in the GnRH-ant group were significantly decreased. Contrarily, the rate of early miscarriage in the GnRH-ant group (13.95% vs. 9.04%, p <.001) was higher than in the GnRH-a group. Furthermore, after treating with GnRH-ant, hESCs showed a reduced expression of HOXA10 and MMP-9 proteins, and a weakened migration ability. Subsequently, by establishing the co-culture system of hESCs and JAR trophoblast spheroids, we found that GnRH-ant inhibited the adhesion and invasion ability of trophoblast cells. Moreover, we also found a decreased expression and phosphorylation of c-kit receptor in decidualized hESCs after treating with GnRH-ant. Similar results as observed above were also confirmed when inhibiting the activation of c-kit receptor by imatinib. Conclusions: GnRH-ant could reduce the motility of hESCs by inhibiting the expression and activation of the C-kit receptor, which impaired the process of embryo implantation. [ABSTRACT FROM AUTHOR]

Introduction: Activated vascular endothelial growth factor receptors (VEGFRs), platelet-derived growth factor receptors (PDGFRs) and c-Kit have been shown to be involved in the growth, invasion and metastasis of non-rhabdomyosarcoma soft tissue sarcoma tumor (NRSTS) with promising results for targeted therapy. Our aim was to assess the expression of these markers among different histological types and correlate with outcomes. Material and methods: This retrospective study included pediatric patients aged ≤ 18 years diagnosed with high-grade NRSTS who were treated at Children Cancer Hospital Egypt 57357 as per the COG NRSTS protocol (ARST0332). Expression of VEGFR2, PDGFRs (α and β) and c-Kit in tumor tissue was assessed by immunohistochemistry and correlated with clinical outcome. Results: Of 113 patients, 96 were eligible for the analysis with a median age of 11 years. Overall, 32.3% demonstrated high expression of PDGFRα, 17.7% for PDGFRβ, 19.8% for VEGFR2 and 8.3% exhibited positive expression for c-kit on the tumor cells. Most cases of synovial sarcoma (45.8%) and 43.7% of patients with undifferentiated sarcoma exhibited high expression of PDGFRα while 41.6% of MPNST showed high expression to PDGFRβ. The 5-year overall survival (OS), event free survival and relapse free survival (RFS) for the whole cohort were 59%, 54% and 60% respectively. In univariate analyses, only PDGFRα had a negative prognostic impact on relapse free survival (RFS) (p =0.03). In multivariate analyses, VEGFR2 was found to have a negative prognostic impact for OS (p = 0.02). Conclusion: Our findings indicated that tyrosine kinase receptors are upregulated in NRSTS and exhibited a distinct expression pattern within various subgroups. High expression of VEGFR2 and PDGFRα significantly correlated with reduced survival and may guide targeted therapy approaches for this poor prognosis group of patients. [ABSTRACT FROM AUTHOR]

Abnormal melanogenesis upon UV exposure causes excessive oxidative stress, leading to hyperpigmentation disorders. As a key rate-limiting enzyme in melanogenesis, tyrosinase is considered a primary target for depigmenting agents. Sophora flavescens is used as a food and in traditional medicine as a valuable source of prenylated flavonoids. The present study aimed to elucidate the anti-melanogenic effect and potential mechanism of kuraridin, one of the major prenylated flavonoids. Kuraridin showed anti-tyrosinase activity with an IC50 value in the nanomolar range, superior to that of kojic acid, a positive control. It significantly reduced tyrosinase activity with the least cytotoxicity, suppressing melanogenesis in α-MSH-induced B16F10 cells. Furthermore, kuraridin considerably reduced melanogenesis in a 3D human skin model. To elucidate the anti-melanogenic mechanism of kuraridin, target genes (KIT, MAP2K1, and PRKCA) and pathways (c-KIT and ETB-R pathways) were identified using network pharmacology. KIT and MAP2K1 are simultaneously involved in the c-KIT cascade and are considered the most important in melanogenesis. PRKCA acts directly on MITF and its downstream enzymes through another pathway. Docking simulation showed strong interactions between kuraridin and c-KIT, ERK1/2, and PKC encoded by target genes. Overall, the present study showed kuraridin to be a novel natural anti-melanogenic agent in hyperpigmentation disorders. [ABSTRACT FROM AUTHOR]

The industrial world exposes living organisms to a variety of metal pollutants. Here we investigated whether such elements affect G-rich sequences susceptible to fold into G-quadruplex (GQ) structures. Thermal stability and conformation of these oligoncleotides was studied at various molar ratios of a variety of heavy metal salts using thermal FRET, transition-FRET (t-FRET) and circular dichroism. Metal ions affected the thermal stability of the GQs to different extents; some metals had no effect on T m while other metals caused small to moderate changes in T m at 1:1 or 1:10 molar ratio. While most of the metals had no major effect, Al3+, Cd2+, Pb2+, Hg2+ and Zn2+ altered the thermal stability and structural features of the GQs. Some metals such as Pb2+ and Hg2+ exhibit differential interactions with telomere, c-myc and c-kit GQs. Overall, toxic heavy metals affect G-quadruplex stability in a sequence and topology dependent manner. This study provides new insight into how heavy metal exposure may affect gene expression and cellular responses. • Heavy metal ions affect the thermal stability of the G-quadruplexes to different extents. • Al3+, Cd2+, Pb2+, Hg2+ and Zn2+ altered the thermal stability and structural features of the GQs. • Pb2+ and Hg2+ exhibit differential interactions with telomere, c-myc and c-kit G-quadruplexes. • Toxic heavy metals affect stability of G-quadruplexes in a sequence and topology dependent manner. • Heavy metal exposure may affect gene expression and cellular responses through direct DNA binding. [ABSTRACT FROM AUTHOR]

Mast cells (MCs) in rat airways have been classified into two subtypes: epithelial MCs and connective tissue MCs (CTMCs). However, the immunohistochemical characteristics, cellular morphology, and distribution of epithelial MCs in the upper airways remain unclear. The present study investigated the morphological characteristics and distribution of epithelial MCs using 5-hydroxytryptamine (5-HT) and other immunohistochemical markers in sectioned or whole-mount preparations of the rat larynx and trachea. A double immunofluorescence analysis revealed the colocalization of 5-HT immunoreactivity with c-kit, a stem cell factor receptor commonly used as a MC marker, in both epithelial MCs and CTMCs. Dopa decarboxylase, an enzyme involved in 5-HT synthesis, was detected in both subtypes, suggesting their ability to synthesize and release 5-HT. Tryptase and histidine decarboxylase (a biosynthetic enzyme of histamine), which are well-known mediators of MCs, were exclusive to CTMCs. Epithelial MCs were pleomorphic with long cytoplasmic processes, whereas CTMCs were round and lacked cytoplasmic processes. The density of epithelial MCs was significantly higher in the glottis and cranial part of the trachea than in the epiglottis and other parts of the trachea. The present results showed that the morphology and immunohistochemical characteristics of epithelial MCs were different from those of CTMCs in the rat larynx and trachea, and variform epithelial MCs were predominantly located at the entrance of the upper airways. Epithelial MCs may release 5-HT to regulate innate immune responses by modulating epithelial cell functions at the entrance gate of the upper airways. [ABSTRACT FROM AUTHOR]

Introduction: Chronic gastritis is a group of conditions commonly characterized by stomach lining inflammation. The study aimed to investigate the clinical and pathological aspects that play a role in its development. Additionally, the study examines the use of CD117 as an immunohistochemistry marker in evaluating mast cell density (MCD). Methods: This retrospective, cross-sectional study was conducted in Iraqi Kurdistan with a sample size of 380 patients. Patient data included gastritis type, neutrophil infiltration severity, mononuclear cell infiltration within the lamina propria, intestinal metaplasia, and glandular atrophy, which were categorized and given a score. The CD117 level was identified using an anti-human rabbit polyclonal antibody. Results: A statistically significant association was revealed between Helicobacter pylori-mediated gastritis and non-specific gastritis with age, activity, H. pylori and MCD, dysplasia, and malignancy. Meanwhile, no association was found with gender, inflammatory infiltrate, intestinal metaplasia, and glandular atrophy. C-Kit exhibited a marked increase in MCD in patients with H. pylori-mediated gastritis, intestinal metaplasia, atrophy, and gastric carcinoma. However, a significant decrease in MCD was observed on repeating endoscopy evaluations for patients after treatment. Conclusion: Regions that exhibit severe inflammation, metaplasia, atrophy, and carcinoma demonstrated an increase in MCD with H. pylori-mediated gastritis. A detailed investigation in clinical practice to screen early diagnosis and treatment needs to be performed in high H. pylori prevalence. [ABSTRACT FROM AUTHOR]

A promising strategy in cancer immunotherapy is to restore or enhance the cytotoxicity of NK cells, among others, by activating the mechanism of antibody-dependent cellular cytotoxicity (ADCC). Monoclonal antibodies targeting tumor antigens, such as rituximab (targeting CD20), induce NK cell-mediated ADCC and have been used to treat B cell malignancies, such as non-Hodgkin lymphoma, but not always successfully. The aim of this study was to analyze the gene expression profile of the NK cells involved in the cytolytic response stimulated by rituximab. NK cells were co-cultured with rituximab-opsonized Raji cells. Sorting into responder and non-responder groups was based on the presence of CD107a, which is a degranulation marker. RNA-seq results showed that the KIT and TNFSF4 genes were strongly down-regulated in the degranulating population of NK cells (responders); this was further confirmed by qRT-PCR. Both genes encode surface proteins with cellular signaling abilities, namely c-KIT and the OX40 ligand. Consistent with our findings, c-KIT was previously reported to correlate inversely with cytokine production by activated NK cells. The significance of these findings for cancer immunotherapy seems essential, as the pharmacological inhibition of c-KIT and OX40L, or gene ablation, could be further tested for the enhancement of the anti-tumor activity of NK cells in response to rituximab. [ABSTRACT FROM AUTHOR]

Mast cells (MCs) are tissue-resident immune cells of a hematopoietic origin that play vital roles in innate and adaptive immunity. Human MCs can be isolated and differentiated from various tissue sources, including cord blood, when supplemented with cytokines such as stem cell factor, interleukin 3, and interleukin 6. Our current research study has shown significant differences in the marker expressions of human cord blood-derived mast cells (hCBMCs) based on donor dependency and the type of medium used for culturing and differentiation. These findings are particularly relevant given the challenges of obtaining specialty media influencing MC phenotypic marker expressions. We found that hCBMCs cultured in StemSpanTM-XF medium had a moderate expression of mast/stem cell growth factor receptor Kit (c-KIT) (mRNA and protein), low expressions of FcεRI (mRNA) and TLR2 (mRNA and protein) but had high levels of MRGPRX2 (mRNA and protein) expressions. In contrast, hCBMCs cultured in Stem Line II medium expressed FcεRI and TLR2 (mRNA and protein) with higher c-KIT but had lower MRGPRX2 expressions compared to the hCBMCs cultured in the StemSpanTM-XF medium. These results suggest that it is crucial to consider both donor dependency and the medium when investigating MC functions and that further research is needed to fully understand the impact of these factors on the hCBMC marker expressions.

Stem cell factor receptor (C-KIT) or platelet-derived growth factor receptor α (PDGFRα) gene mutations have been identified as oncogenic drivers for most gastrointestinal stromal tumors (GISTs). Thus, small-molecule inhibitors of C-KIT or PDGFRα have emerged as effective treatments for GISTs. Although the currently approved first- to fourth-line drugs are initially effective against GISTs, the inevitable development of drug resistance remains an unmet challenge. To address secondary mutations leading to drug resistance, several novel selective C-KIT/PDGFRα small-molecule inhibitors have been developed and clinically studied. This review summarizes the pathogenesis, treatment, and drug resistance mechanisms of GISTs and briefly describes current challenges and future efforts for GIST treatment using small-molecule kinase inhibitors.

KIT is a gene coding for tyrosine kinase receptor, which was identified as the ligand of stem cell factor. Its role in disease was first identified in gastrointestinal stromal tumor. However, later, this gene was found to be implicated in many other benign and malignant tumors. C-KIT has been studied as the first biomarker for targeted therapy. Herein we review its structure, function and role in various non-neoplastic and neoplastic diseases. [ABSTRACT FROM AUTHOR]

Background: Critical limb ischemia (CLI) is the end stage of peripheral artery disease (PAD), and around 30% of CLI patients are ineligible for current treatments. The angiogenic benefits of c-Kit have been reported in the ischemia scenario; however, the present study demonstrates the effects of specific endothelial c-Kit signaling in arteriogenesis during hindlimb ischemia. Methods: We created conditional knockout mouse models that decrease c-Kit (c-Kit VE-Cadherin CreERT2—c-Kit) or its ligand (SCF VE-Cadherin CreERT2—SCF) specifically in endothelial cells (ECs) after tamoxifen treatment. These mice and a control group (wild-type VE-Cadherin CreERT2—WT) were subjected to hindlimb ischemia or aortic crush to evaluate perfusion/arteriogenesis and endothelial barrier permeability, respectively. Results: Our data confirmed the lower gene expression of c-Kit and SCF in the ECs of c-Kit and SCF mice, respectively. In addition, we confirmed the lower percentage of ECs positive for c-Kit in c-Kit mice. Further, we found that c-Kit and SCF mice had better limb perfusion and arteriogenesis compared to WT mice. We also demonstrated that c-Kit and SCF mice had a preserved endothelial barrier after aortic crush compared to WT. Conclusions: Our data demonstrate the deleterious effects of endothelial SCF/c-Kit signaling on arteriogenesis and endothelial barrier integrity. [ABSTRACT FROM AUTHOR]

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IntroductionActivated vascular endothelial growth factor receptors (VEGFRs), platelet-derived growth factor receptors (PDGFRs) and c-Kit have been shown to be involved in the growth, invasion and metastasis of non-rhabdomyosarcoma soft tissue sarcoma tumor (NRSTS) with promising results for targeted therapy. Our aim was to assess the expression of these markers among different histological types and correlate with outcomes.Material and methodsThis retrospective study included pediatric patients aged ≤ 18 years diagnosed with high-grade NRSTS who were treated at Children Cancer Hospital Egypt 57357 as per the COG NRSTS protocol (ARST0332). Expression of VEGFR2, PDGFRs (α and β) and c-Kit in tumor tissue was assessed by immunohistochemistry and correlated with clinical outcome.ResultsOf 113 patients, 96 were eligible for the analysis with a median age of 11 years. Overall, 32.3% demonstrated high expression of PDGFRα, 17.7% for PDGFRβ, 19.8% for VEGFR2 and 8.3% exhibited positive expression for c-kit on the tumor cells. Most cases of synovial sarcoma (45.8%) and 43.7% of patients with undifferentiated sarcoma exhibited high expression of PDGFRα while 41.6% of MPNST showed high expression to PDGFRβ. The 5-year overall survival (OS), event free survival and relapse free survival (RFS) for the whole cohort were 59%, 54% and 60% respectively. In univariate analyses, only PDGFRα had a negative prognostic impact on relapse free survival (RFS) (p=0.03). In multivariate analyses, VEGFR2 was found to have a negative prognostic impact for OS (p = 0.02).ConclusionOur findings indicated that tyrosine kinase receptors are upregulated in NRSTS and exhibited a distinct expression pattern within various subgroups. High expression of VEGFR2 and PDGFRα significantly correlated with reduced survival and may guide targeted therapy approaches for this poor prognosis group of patients.

Tyrosine kinases (TKs) are catalytic enzymes activated by auto-phosphorylation that function by phosphorylating tyrosine residues on downstream substrates. Tyrosine kinase inhibitors (TKIs) have been heavily exploited as cancer therapeutics, primarily due to their role in autophagy, blood vessel remodeling and inflammation. This suggests tyrosine kinase inhibition as an appealing therapeutic target for exploiting convergent mechanisms across several neurodegenerative disease (NDD) pathologies. The overlapping mechanisms of action between neurodegeneration and cancer suggest that TKIs may play a pivotal role in attenuating neurodegenerative processes, including degradation of misfolded or toxic proteins, reduction of inflammation and prevention of fibrotic events of blood vessels in the brain. In this review, we will discuss the distinct roles that select TKs have been shown to play in various disease-associated processes, as well as identify TKs that have been explored as targets for therapeutic intervention and associated pharmacological agents being investigated as treatments for NDDs.

Cardiac fibroblast (CF) population heterogeneity and plasticity present a challenge for categorization of biological and functional properties. Distinct molecular markers and associated signaling pathways provide valuable insight for CF biology and interventional strategies to influence injury response and aging-associated remodeling. Receptor tyrosine kinase c-Kit mediates cell survival, proliferation, migration, and is activated by pathological injury. However, the biological significance of c-Kit within CF population has not been addressed. An inducible reporter mouse detects c-Kit promoter activation with Enhanced Green Fluorescent Protein (EGFP) expression in cardiac cells. Coincidence of EGFP and c-Kit with the DDR2 fibroblast marker was confirmed using flow cytometry and immunohistochemistry. Subsequently, CFs expressing DDR2 with or without c-Kit was isolated and characterized. A subset of DDR2+ CFs also express c-Kit with coincidence in ~ 8% of total cardiac interstitial cells (CICs). Aging is associated with decreased number of c-Kit expressing DDR2+ CFs, whereas pathological injury induces c-Kit and DDR2 as well as the frequency of coincident expression in CICs. scRNA-Seq profiling reveals the transcriptome of c-Kit expressing CFs as cells with transitional phenotype. Cultured cardiac DDR2+ fibroblasts that are c-Kit+ exhibit morphological and functional characteristics consistent with youthful phenotypes compared to c-Kit- cells. Mechanistically, c-Kit expression correlates with signaling implicated in proliferation and cell migration, including phospho-ERK and pro-caspase 3. The phenotype of c-kit+ on DDR2+ CFs correlates with multiple characteristics of 'youthful' cells. To our knowledge, this represents the first evaluation of c-Kit biology within DDR2+ CF population and provides a fundamental basis for future studies to influence myocardial biology, response to pathological injury and physiological aging.

Introduction: Cisplatin chemotherapy targets many tumors. However, it affects the submandibular gland causing its hypofunction. Hesperidin has antioxidant and anti-inflammatory actions. Aim of the Work: Was to evaluate the biochemical and histological alterations caused by two regimens of cisplatin application on rat's submandibular gland and to assess the effect of hesperidin against these changes. Materials and Methods: 70 adult male albino rats were divided into 4 groups. Group I; control rats, Group II was given hesperidin (100mg/kg/day) orally from day 1 until the experiment end. Group III received single high cisplatin dose (intraperitoneally 12mg/kg) on 8th day and subdivided into subgroup IIIa that received cisplatin only and IIIb received cisplatin + hesperidin as group II. Group IV received multiple low cisplatin doses (intraperitoneally 6mg/kg) once a week starting from 8th day and subdivided into subgroup IVa that received cisplatin only and IVb received cisplatin + hesperidin as group II. Submandibular glands were dissected out and processed for biochemical, histological and immunohistochemical studies. c-Kit was used as a stem cell marker. Results: Subgroups IIIa & IVa showed biochemical, histological, and ultrastructural changes that was more marked in IIIa. There was a significant elevation of malondialdehyde and reduction of antioxidant enzyme activities, disturbance of gland architecture, acinar and duct cell degeneration, significant elevation in % area of collagen fibers and significant reduction in % area of c- kit immune reaction. Subgroups IIIb and IVb showed improvement in the histological picture of the gland with a significant increase in % area of c- kit immune reaction. Conclusion: Cisplatin causes changes in submandibular gland being more marked with the single high dose. Hesperidin partially alleviates these changes through its antioxidant action and enhanced activation of secretory complex stem cells. So, hesperidin can be used clinically with chemotherapy to prevent its side effects. [ABSTRACT FROM AUTHOR]

A series of novel echinatin derivatives with 1,3,4-oxadiazole moieties were designed and synthesized. Most of the newly synthesized compounds exhibited moderate antiproliferative activity against the four cancer cell lines. Notably, Compound T4 demonstrated the most potent activity, with IC50 values ranging from 1.71 µM to 8.60 µM against the four cancer cell lines. Cell colony formation and wound healing assays demonstrated that T4 significantly inhibited cell proliferation and inhibited migration. We discovered that T4 exhibited moderate binding affinity with the c-KIT protein through reverse docking. The results were effectively validated through subsequent molecular docking and c-KIT enzyme activity assays. In addition, Western blot analysis revealed that T4 inhibits the phosphorylation of downstream proteins of c-KIT. The results provide valuable inspiration for exploring novel insights into the design of echinatin-related hybrids as well as their potential application as c-KIT inhibitors to enhance the efficacy of candidates. [ABSTRACT FROM AUTHOR]

We report a subcutaneous mastocytoma in a mid-aged Italian greyhound dog with a small 41 bp genomic deletion of the c-kit gene leading to skipping of the authentic 3′-splice junction of intron 10. The shift to an alternative splice junction in exon 11 leads to a mis-spliced in-frame mRNA transcript with a 27 bp deletion of exon 11 coding for 9 amino acids in the juxtamembrane negative regulatory domain of c-kit tyrosine kinase. In the tumor, c-kit was activated as revealed by more pronounced c-kit-regulated signaling by the PI3K/Akt and G-coupled receptor pathways. The same 9 amino acids deletion was reported in several human gastrointestinal stromal tumors (GIST) pointing to a remarkable similarity of c-kit activation by small deletions and aberrant splicing in humans and dogs, independent of exact sequence context, tumor type and location. Interestingly, the alternative splice junction in exon 11 has been conserved in Primates but less in other Orders with increased body temperature such as ruminants. We hypothesize that elevated body temperature has acted as evolutionary pressure to eliminate the alternative splice site at this hotspot. At a molecular level, hyperthermia may increase the frequency of small deletions in the c-kit gene by facilitating base slipping or hindering repair. An RT-qPCR assay was developed to detect c-kit alternative splicing in tumors and cell lines exposed to hyperthermia. The molecular mechanisms of tumorigenesis are discussed.

Introduction: Gastrointestinal stromal tumors (GIST) are the most common mesenchymal neoplasms of the gastrointestinal tract and their diagnosis is mainly based on histopathology and immunohistochemical study with CD117 marker. However, there are many GIST tumors that are CD117 negative and for such cases come the role of other IHC markers. The study aimed to observe the various histological features and demographic profiles of GISTs and the role of various immunohistochemical markers in the confirmation of diagnosis. Methodology: A hospital-based observational study was conducted on 40 tumor resection materials diagnosed as GIST from April 2017 to February 2023 at tertiary care center K.E.M. Hospital, Pune. All the cases underwent histopathological examination with standard procedure of tissue processing, staining and IHC with CD117. Those cases who were morphologically designated as GIST on HPE were evaluated with a panel of IHC markers like C-KIT, CD34, SMA, desmin, S-100 and vimentin. Results: 35 out of 40 cases (87.5%) were found to be positive for CD117 while IHC markers like CD34, SMA, desmin, S-100 and vimentin were found to be positive in 60%, 20%, 5%, 2.5% and 80% cases respectively. Also, we found significant relationship between histopathological groups different progressive disease risk groups with necrosis, cytologic atypia, cellularity and mucosal invasion (p-value

AbstractContext Bombax ceiba Linnaeus (Bombacaceae) is known as silk cotton tree, the flowers of which are used in many medicinal applications.Objective To investigate the therapeutic effect of B. ceiba flower aqueous extracts (BCE) against loperamide-induced constipation and characterize the chemical composition of BCE.Materials and methods Sixty male Kunming mice were divided into control (saline), model (10 mg/kg loperamide + saline), phenolphthalein (10 mg/kg loperamide + 10 mg/kg phenolphthalein) and different dosage of BCE (10 mg/kg loperamide + 40, 80 and 160 mg/kg BCE, respectively) groups, and received intragastric administrations for eight days. Faecal water content, number of faeces, first black-stool defecation time and gastrointestinal transit rates were evaluated. Various biochemical and molecular biomarkers were assessed in blood and colon. UPLC-ESI-QTOF-MS/MS was used to tentatively identify the composition of the BCE.Results BCE treatment (160 mg/kg) could increase faecal water (15.75%), faeces number (11.65%), gastrointestinal transit rate (25.37%) and decrease first black-stool defecation time (24.04%). The BCE (80 mg/kg) increased the serum level of motilin (30.62%), gastrin (54.46%) and substance P (18.99%), and decreased somatostatin (19.47%). Additionally, the BCE (160 mg/kg) reduced the mucosal damage, restored colonic goblet cell function, down-regulated the protein expression of AQP3 (33.60%) and increased c-kit protein expression (11.63%). Twelve known compounds, including protocatechuic acid, chlorogenic acid and rutin, previously reported in B. ceiba, were identified in the BCE.Discussion and conclusions This study suggested that BCE is a promising agent for the treatment of constipation.

ABSTRACT KIT protein is associated with the etiology of canine mast cell tumors (MCT); however, the expression patterns of KIT are highly variable. The aim of this study was to determine if KIT patterns are related with eosinophil count in MCT. Hematoxylin eosin and May Grünwald-Giemsa stain techniques were applied, histological grading and eosinophil counting were performed in 48 MCT samples. Immunohistochemical evaluation was performed with IL-5, VEGFr, and c-KIT antibodies. The percentage of immunolabeling with IL-5 and VEGFr was determined, and the samples incubated with c-KIT were graded according to the immunolabeling pattern. Comparison of the mean eosinophil count between the histological grades and the different KIT expression patterns demonstrated a significant difference between KIT pattern 1 and KIT pattern 3, KIT pattern 3 showed a higher mean of eosinophil count. There was no significant correlation between eosinophil count and KIT patterns (p = 0.2648). However, a positive correlation was observed between the KIT patterns and Patnaik and Kiupel grades (p = 0.0006 and p = 0.0267, respectively). There was no significant correlation between eosinophil count, IL-5, or VEGFr. Further studies should determine whether eosinophil counts are an independent predictor of clinical outcome or simply correlated with already known predictors.

Introduction Smoking is an important risk factor for inducing renal cell carcinoma (RCC), but its specific mechanism affecting the development of RCC remains to be elucidated. Chromophobe RCC (ChRCC) is a subtype of RCC. Many studies have shown smoking is closely associated with RCC occurrence and c-kit plays a critical role in the progression of RCC, however, few studies focus on ChRCC. This study investigated the molecular mechanism between smoking and the c-kit pathway in ChRCC. Methods Differentially expressed genes (DEGs) were obtained from The Cancer Genome Atlas (TCGA) in ChRCC and the expression of KIT in ChRCC was analyzed through the TCGA database combined with Gene Expression Omnibus (GEO) and oncomine databases. Moreover, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses and Protein Protein Interaction (PPI) network analysis were performed to explore the function of KIT and correlated DEGs as well as its co-expression genes in ChRCC. Finally, ChRCC patient samples were used to verify the effect of smoking on the c-kit expression. Results The results showed that KIT is one of the DEGs and plays a vital role in ChRCC tumorigenesis. Interestingly, the expression of c-kit in cancer tissues of 27 smoking patients was significantly higher than that of 25 non-smoking patients (p

Mast cells (MC) are central effectors of allergic disease and distinct subsets with varying amounts of tryptase, chymase, and carboxypeptidase A3, and cathepsin G is distributed throughout the body. Their involvement in a diverse range of non-allergic illnesses mediated by a complex range of preformed and newly synthesized mediators is now increasingly recognized. The latter especially include conditions under the umbrella term of mast cell activation syndrome. In allergic disease, much has been written about the mechanisms by which the early and rapidly acting mediators produce both localized and systemic allergic symptoms. The role of chymase is presently underappreciated but there is increased awareness that MCs contain significant amounts of preformed TNF alpha and synthesize and releases a wide range of inflammatory cytokines such as interleukins (IL) 1β, IL6, IL31, and IL33. These can aggravate itching and perpetuate inflammation and likely contribute to the late constitutional symptoms seen in allergic reactions. Importantly, their involvement helps to clarify the role of MCs in stress and non-parasitic infections. Presently, unexplained is the increasing incidence of significant acute allergic reactions within a relatively short time frame. In this context, there is increasing interest in the environmental, menstrual, endocrine, circadian, and psychological factors that influence MC activation as well as the endocrine pathways involving the renin angiotensin system that oppose hypotension. In non-allergic diseases with normal numbers of MCs, reduced thresholds for activation may be produced by various combinations of life and dietary factors. Diagnosing these conditions is difficult but may be helped by urinary analysis of prostaglandin metabolites. The investigation and management of mastocytosis with and without mutations of c-kit is also relevant to allergic disease and the new medications used may also be helpful in idiopathic anaphylaxis. This knowledge may open a new chapter in human diseases and mast cell regulation. [ABSTRACT FROM AUTHOR]

Salivary gland hypofunction adversely affects the oral environment and daily life by causing dry mouth (xerostomia). Senescence-related atrophy of salivary gland tissues is one cause of xerostomia, and it is particularly common among the elderly. However, the underlying mechanism is poorly understood, and no treatment has been established. Therefore, we examined age-related changes in senescence-associated secretory phenotype (SASP) factors, which regulate stemness and cellular senescence, in mouse submandibular glands. We analyzed the submandibular glands of 6-week-old (young group, n = 6) and 82-week-old mice (aged group, n = 6). We performed salivary flow rate measurements, histological analysis including immunohistochemistry, and quantitative real-time PCR. The salivary flow rate was significantly lower in the aged group than in the young group. In addition, immunostaining and quantitative real-time PCR illustrated that aquaporin-5 and α-amylase expressions were significantly decreased in aged mice, indicating salivary gland hypofunction. c-Kit and cytokeratin 5 expressions were also significantly decreased in this group, suggesting that the regenerative abilities of the submandibular glands were reduced because of decreased stem and progenitor cell counts. Furthermore, the levels of p16INK4a and p21 (the senescence markers) and TGF-β1 and IL-6 (SASP factors) were significantly increased in mice, suggesting that senescence had been promoted. The decreased numbers of stem and progenitor cells and increased levels of SASP factors might be associated with age-related changes in mouse submandibular glands. These results might facilitate the development of treatments for senescence-related submandibular gland hypofunction. [ABSTRACT FROM AUTHOR]

c-KIT is an important diagnostic marker in salivary gland tumours and is expressed in most adenoid cystic carcinomas. Histologically similar salivary gland tumours with variable immunohistochemical expression for c-KIT pose a challenge and make diagnostic reliability ambivalent. An electronic search was performed in MEDLINE by PubMed, Google Scholar, Scopus, Trip, Cochrane Library, and EMBASE up to 31 December 2023, without period restriction. The articles that investigated CD117 or c-KIT in salivary gland tumours were included for review. Sensitivity, specificity, and positive and negative predictive values of c-KIT immunohistochemical expressions were derived and subjected to meta-analysis using Open Meta analyst for Sierra software. The risk of bias in selected studies was analysed using the QUADAS-2 tool, and RevMan 5.4 was used to output the result. Forty-three articles were reviewed, and 2285 salivary gland cases were analysed. Adenoid cystic carcinoma had an overall expression of 84.9%. A similar expression was found in epimyoepithelial carcinoma (79.1%), lymphoepithelial carcinoma (75%), myoepithelial carcinoma (60.8%), monomorphic adenoma (94.1%), and pleomorphic adenoma (74.7%). The sensitivity, specificity, and positive and negative predictive values of c-KIT/CD117 for adenoid cystic carcinoma with other salivary gland tumours were 84.99%, 69.09%, 84.79%, and 69.41%, respectively. Current evidence shows that c-KIT, despite its sensitivity, is not specific and therefore cannot be a useful diagnostic marker for distinguishing adenoid cystic carcinoma from other salivary gland tumours. Further research on other salivary gland tumours that exhibit comparable expression is necessary to validate the diagnostic accuracy of c-KIT. [ABSTRACT FROM AUTHOR]

Bombax ceiba Linnaeus (Bombacaceae) is known as silk cotton tree, the flowers of which are used in many medicinal applications. To investigate the therapeutic effect of B. ceiba flower aqueous extracts (BCE) against loperamide-induced constipation and characterize the chemical composition of BCE. Sixty male Kunming mice were divided into control (saline), model (10 mg/kg loperamide + saline), phenolphthalein (10 mg/kg loperamide + 10 mg/kg phenolphthalein) and different dosage of BCE (10 mg/kg loperamide + 40, 80 and 160 mg/kg BCE, respectively) groups, and received intragastric administrations for eight days. Faecal water content, number of faeces, first black-stool defecation time and gastrointestinal transit rates were evaluated. Various biochemical and molecular biomarkers were assessed in blood and colon. UPLC-ESI-QTOF-MS/MS was used to tentatively identify the composition of the BCE. BCE treatment (160 mg/kg) could increase faecal water (15.75%), faeces number (11.65%), gastrointestinal transit rate (25.37%) and decrease first black-stool defecation time (24.04%). The BCE (80 mg/kg) increased the serum level of motilin (30.62%), gastrin (54.46%) and substance P (18.99%), and decreased somatostatin (19.47%). Additionally, the BCE (160 mg/kg) reduced the mucosal damage, restored colonic goblet cell function, down-regulated the protein expression of AQP3 (33.60%) and increased c-kit protein expression (11.63%). Twelve known compounds, including protocatechuic acid, chlorogenic acid and rutin, previously reported in B. ceiba, were identified in the BCE. This study suggested that BCE is a promising agent for the treatment of constipation. [ABSTRACT FROM AUTHOR]

Tuberous Sclerosis Complex (TSC) is an autosomal dominant genetic disease caused by mutations in either TSC1 or TSC2 genes. Approximately, two million individuals suffer from this disorder worldwide. TSC1 and TSC2 code for the proteins harmartin and tuberin, respectively, which form a complex that regulates the mechanistic target of rapamycin complex 1 (mTORC1) and prevents uncontrollable cell growth. In the kidney, TSC presents with the enlargement of benign tumors (angiomyolipomas) and cysts whose presence eventually causes kidney failure. The factors promoting cyst formation and tumor growth in TSC are poorly understood. Recent studies on kidney cysts in various mouse models of TSC, including mice with principal cell- or pericyte-specific inactivation of TSC1 or TSC2, have identified a unique cystogenic mechanism. These studies demonstrate the development of numerous cortical cysts that are predominantly comprised of hyperproliferating A-intercalated (A-IC) cells that express both TSC1 and TSC2. An analogous cellular phenotype in cystic epithelium is observed in both humans with TSC and in TSC2+/- mice, confirming a similar kidney cystogenesis mechanism in TSC. This cellular phenotype profoundly contrasts with kidney cysts found in Autosomal Dominant Polycystic Kidney Disease (ADPKD), which do not show any notable evidence of A-IC cells participating in the cyst lining or expansion. RNA sequencing (RNA-Seq) and confirmatory expression studies demonstrate robust expression of Forkhead Box I1 (FOXI1) transcription factor and its downstream targets, including apical H+-ATPase and cytoplasmic carbonic anhydrase 2 (CAII), in the cyst epithelia of Tsc1 (or Tsc2) knockout (KO) mice, but not in Polycystic Kidney Disease (Pkd1) mutant mice. Deletion of FOXI1, which is vital to H+-ATPase expression and intercalated (IC) cell viability, completely inhibited mTORC1 activation and abrogated the cyst burden in the kidneys of Tsc1 KO mice. These results unequivocally demonstrate the critical role that FOXI1 and A-IC cells, along with H+-ATPase, play in TSC kidney cystogenesis. This review article will discuss the latest research into the causes of kidney cystogenesis in TSC with a focus on possible therapeutic options for this devastating disease. [ABSTRACT FROM AUTHOR]

The first part of this contribution describes solutions that were developed to achieve progressively more efficient syntheses of the thiopeptide natural products, micrococcins P1 and P2 (MP1–MP2), with an eye toward exploring their potential as a source of new antibiotics. Such efforts enabled investigations on the medicinal chemistry of those antibiotics, and inspired the development of the kinase inhibitor, Masitinib®, two candidate oncology drugs, and new antibacterial agents. The studies that produced such therapeutic resources are detailed in the second part. True to the theme of this issue, "Organic Synthesis and Medicinal Chemistry: Two Inseparable Partners", an important message is that the above advances would have never materialized without the support of curiosity-driven, academic synthetic organic chemistry: a beleaguered science that nonetheless has been—and continues to be—instrumental to progress in the biomedical field. [ABSTRACT FROM AUTHOR]

Background: Corebinding factor acute myeloid leukemia (CBF-AML) is the most common cytogenetic subtype of pediatric AML. CBF-AML is associated with a relatively favorable outcome, although the relapse rate of approximately 40% indicates a high degree of clinical heterogeneity. The clinical impact of additional cytogenetic aberrations, including c-KIT and CEBPA mutations, in pediatric CBF-AML has not been well characterized, especially in the multi-ethnic region of Yunnan Province in China. Methods: In this study, we retrospectively analyzed the clinical features, gene mutations, and prognoses of 72 pediatric patients newly diagnosed with non-M3 AML in Kunming Children's Hospital, China, from January 1, 2015 to May 31, 2020. Results: Of the 72 pediatric patients with AML, 46% (33/72) had CBF-AML. Thirteen patients with CBF-AML (39%) had c-KIT mutations, five (15%) had CEBPA mutations, and eleven (33.3%) had no other cytogenetic aberrations. The c-KIT mutations, resulting from single nucleotide substitutions and small insertions or deletions, occurred in exons 8 and 17. All of the CBF-AML-associated CEBPA mutations were single mutations and occurred in patients with RUNX1-RUNX1T1 fusion. We found no significant differences in the clinical data between CBF-AML patients with c-KIT or CEBPA mutations and CBF-AML patients without other aberrations, and no prognostic significance was established for these mutations. Conclusion: Our study is the first to report the clinical impact of c-KIT and CEBPA mutations in pediatric patients with non-M3 CBF-AML from the multi-ethnic Yunnan Province, China. c-KIT and CEBPA mutations occurred at a higher frequency in CBF-AML cases and were associated with unique clinical characteristics; however, no potential molecular prognostic markers were identified.

Background: Critical limb ischemia (CLI) is the end stage of peripheral artery disease (PAD), and around 30% of CLI patients are ineligible for current treatments. The angiogenic benefits of c-Kit have been reported in the ischemia scenario; however, the present study demonstrates the effects of specific endothelial c-Kit signaling in arteriogenesis during hindlimb ischemia. Methods: We created conditional knockout mouse models that decrease c-Kit (c-Kit VE-Cadherin CreERT2—c-Kit) or its ligand (SCF VE-Cadherin CreERT2—SCF) specifically in endothelial cells (ECs) after tamoxifen treatment. These mice and a control group (wild-type VE-Cadherin CreERT2—WT) were subjected to hindlimb ischemia or aortic crush to evaluate perfusion/arteriogenesis and endothelial barrier permeability, respectively. Results: Our data confirmed the lower gene expression of c-Kit and SCF in the ECs of c-Kit and SCF mice, respectively. In addition, we confirmed the lower percentage of ECs positive for c-Kit in c-Kit mice. Further, we found that c-Kit and SCF mice had better limb perfusion and arteriogenesis compared to WT mice. We also demonstrated that c-Kit and SCF mice had a preserved endothelial barrier after aortic crush compared to WT. Conclusions: Our data demonstrate the deleterious effects of endothelial SCF/c-Kit signaling on arteriogenesis and endothelial barrier integrity.

Tuberous Sclerosis Complex (TSC) is an autosomal dominant genetic disease caused by mutations in either TSC1 or TSC2 genes. Approximately, two million individuals suffer from this disorder worldwide. TSC1 and TSC2 code for the proteins harmartin and tuberin, respectively, which form a complex that regulates the mechanistic target of rapamycin complex 1 (mTORC1) and prevents uncontrollable cell growth. In the kidney, TSC presents with the enlargement of benign tumors (angiomyolipomas) and cysts whose presence eventually causes kidney failure. The factors promoting cyst formation and tumor growth in TSC are poorly understood. Recent studies on kidney cysts in various mouse models of TSC, including mice with principal cell- or pericyte-specific inactivation of TSC1 or TSC2, have identified a unique cystogenic mechanism. These studies demonstrate the development of numerous cortical cysts that are predominantly comprised of hyperproliferating A-intercalated (A-IC) cells that express both TSC1 and TSC2. An analogous cellular phenotype in cystic epithelium is observed in both humans with TSC and in TSC2+/− mice, confirming a similar kidney cystogenesis mechanism in TSC. This cellular phenotype profoundly contrasts with kidney cysts found in Autosomal Dominant Polycystic Kidney Disease (ADPKD), which do not show any notable evidence of A-IC cells participating in the cyst lining or expansion. RNA sequencing (RNA-Seq) and confirmatory expression studies demonstrate robust expression of Forkhead Box I1 (FOXI1) transcription factor and its downstream targets, including apical H+-ATPase and cytoplasmic carbonic anhydrase 2 (CAII), in the cyst epithelia of Tsc1 (or Tsc2) knockout (KO) mice, but not in Polycystic Kidney Disease (Pkd1) mutant mice. Deletion of FOXI1, which is vital to H+-ATPase expression and intercalated (IC) cell viability, completely inhibited mTORC1 activation and abrogated the cyst burden in the kidneys of Tsc1 KO mice. These results unequivocally demonstrate the critical role that FOXI1 and A-IC cells, along with H+-ATPase, play in TSC kidney cystogenesis. This review article will discuss the latest research into the causes of kidney cystogenesis in TSC with a focus on possible therapeutic options for this devastating disease.

One of the best and most effective applied and tolerable approaches for cardioprotection is the regular exercise. In the situation of exercise activity and even cardiac ischemic injury, the activity of the myocardial stem cells and their recruiting factors are changed so that contribute to the adaptation and repairment of the myocardium. The aim of this study was to investigate the effect of myocardial preconditioning with HIIT on SDF-1a myocardial levels, CXCR4 receptors, and c-kit after acute myocardial infarction in male rats. Twenty male Wistar were randomly divided into 4 groups: control (C), training (T), myocardial infarction (MI), and training + myocardial infarction (T + MI). The training groups performed 2 weeks of high-intensity interval training in four sections. Protein expression of SDF-1, C-Kit, and CXCR4 receptors was measured by the western blot method in the myocardial tissue, and myocardial injury enzymes were measured in serum. The results showed that SDF-1, CXCR4 receptors, and C-Kit had a significant increase after two weeks of HIIT and myocardial infarction. Also, serum enzyme measurements showed a positive effect of exercise, so that in the myocardium injury, enzymes significantly increased in the MI group compared with the other three groups (p < 0.001), and there was a significant difference between the groups of T + MI in all of the enzymes of the myocardium injury compared to the C and T groups. Even short terms of HIIT can increase the levels of proteins SDF1-a, C-Kit, and CXCR4 receptors in order to cardioprotection against myocardial injury through the recruitment of stem cells. [ABSTRACT FROM AUTHOR]

The study was conducted to investigate the effect of the treatment with imatinib, a c-kit specific inhibitor, on the neointimal hyperplasia (NIH) of aortocaval fistula (ACF) in adenine-induced renal failure rats. All rats were randomly assigned to 4 groups: rats were fed on a normal diet (normal group); rats were fed on a 0.75% adenine-rich diet (renal failure group). The remaining rats underwent ACF after receiving a 0.75% adenine-rich diet and received daily saline gavage (model group) or imatinib gavage (imatinib group) for 7 days after surgery. Immunohistochemical method was used to detect c-kit expression, and Elastomeric Verhoeff-Van Gieson (EVG) staining was used to observe morphological changes of the ACF. The Pearson correlation analysis was used to evaluate the correlations of c-kit expression with intimal thickness and the percentage of stenosis, respectively. The renal failure group showed positive c-kit expression on the intima of the inferior vena cava (IVC), whereas the normal group did not. Compared to the model group, intimal thickness (P = 0.001), the percentage of stenosis (P = 0.006) and c-kit expression (P = 0.04) were decreased in the imatinib group at 8 weeks postoperatively. C-kit expression was positively correlated with both intimal thickness and percentage of stenosis (intimal thickness: R = 0.650, P = 0.003; the percentage of stenosis: R = 0.581, P = 0.011) in both the model and imatinib groups. Treatment with imatinib, a c-kit specific inhibitor, was useful to delay the NIH of ACF in adenine-induced renal failure rats. • C-kit expression in the intima of aortocaval fistula (ACF) was positively correlated with both intimal thickness and percentage of stenosis. • Imatinib can be used to inhibit c-kit expression in the intima of venous outflow tracts in ACF. [ABSTRACT FROM AUTHOR]

c-Kit is a type III receptor tyrosine kinase (RTK) that has an essential role in various biological functions including gametogenesis, melanogenesis, hematopoiesis, cell survival, and apoptosis. c-KIT aberrations, either overexpression or loss-of-function mutations, have been implicated in the pathogenesis and development of many cancers, including gastrointestinal stromal tumors, mastocytosis, acute myeloid leukemia, breast, thyroid, and colorectal cancer, making c-KIT an attractive molecular target for the treatment of cancers. Therefore, a lot of effort has been put into investigating the utility of tyrosine kinase inhibitors for the management of c-KIT mutated tumors. This review of the literature illustrates the role of c-KIT mutations in many cancers, aiming to provide insights into the role of TKIs as a therapeutic option for cancer patients with c-KIT aberrations. In conclusion, c-KIT is implicated in different types of cancer, and it could be a successful molecular target; however, proper detection of the underlying mutation type is required before starting the appropriate personalized therapy. [ABSTRACT FROM AUTHOR]

The visual appearance of humans is derived significantly from our skin and hair color. While melanin from epidermal melanocytes protects our skin from the damaging effects of ultraviolet radiation, the biological value of pigmentation in the hair follicle, particularly on the scalp, is less clear. In this study, we explore the heterogeneity of pigment cells in the human scalp anagen hair follicle bulb, a site conventionally viewed to be focused solely on pigment production for transfer to the hair shaft. Using c-KIT/CD117 microbeads, we isolated bulbar c-KIT-positive and c-KIT-negative melanocytes. While both subpopulations expressed MITF, only the c-KIT-positive fraction expressed SOX10. We further localized bulbar melanocyte subpopulations (expressing c-KIT, SOX10, MITF, and DCT) that exhibited distinct/variable expression of downstream differentiation-associated melanosome markers (e.g., gp100 and Melan-A). The localization of a second 'immature' SOX10 negative melanocyte population, which was c-KIT/MITF double-positive, was identified outside of the melanogenic zone in the most peripheral/proximal matrix. This study describes an approach to purifying human scalp anagen hair bulb melanocytes, allowing us to identify unexpected levels of melanocyte heterogeneity. The function of the more immature melanocytes in this part of the hair follicle remains to be elucidated. Could they be in-transit migratory cells ultimately destined to synthesize melanin, or could they contribute to the hair follicle in non-melanogenic ways? [ABSTRACT FROM AUTHOR]

Pulmonary arterial hypertension (PAH) is a complex disorder characterized by vascular remodeling and a consequent increase in pulmonary vascular resistance. The histologic hallmarks of PAH include plexiform and neointimal lesions of the pulmonary arterioles, which are composed of dysregulated, apoptosis-resistant endothelial cells and myofibroblasts. Platelet-derived growth factor receptors (PDGFR) α and β, colony stimulating factor 1 receptor (CSF1R), and mast/stem cell growth factor receptor kit (c-KIT) are closely related kinases that have been implicated in PAH progression. In addition, emerging data indicate significant crosstalk between PDGF signaling and the bone morphogenetic protein receptor type 2 (BMPR2)/transforming growth factor β (TGFβ) receptor axis. This review will discuss the importance of the PDGFR-CSF1R-c-KIT signaling network in PAH pathogenesis, present evidence that the inhibition of all three nodes in this kinase network is a potential therapeutic approach for PAH, and highlight the therapeutic potential of seralutinib, currently in development for PAH, which targets these pathways. [ABSTRACT FROM AUTHOR]

Introduction: Ovarian cancer is one of leading causes of cancer related death in gynecology. CD117 is a tyrosine kinase receptor that plays an important role in regulation of apoptosis, cell proliferation and adhesion by binding to its ligand-stem cell factor. Recent studies demonstrated its aberrant overexpression in various malignancies and concluded that it may play a pivotal role in carcinogenesis. Aim: To evaluate CD117 expression in ovarian surface epithelial tumours. Materials and Methods: This retrospective study included 30 ovarian epithelial borderline, low and highly malignant tumours' formalin-fixed paraffin-blocks (FFPE) tissue blocks. Tissue sections were subjected to the routine haematoxylin-eosin stain and with the anti-CD117 immunohistochemically. Results: There is a high significant difference in CD117 expression between borderline and malignant groups (P = 0.001). Additionally, there was significant difference in expression in relation to histopathological type (serous versus non-serous) in low-grade and the high-grade ovarian surface epithelial tumours (p=0.04, p=0.035 respectively). Tumour grade and stage strongly correlates with CD117 expression (p=0.014, p=0.019 respectively). Conclusion: We concluded that CD117 expression was significantly correlated with higher ovarian tumour grade and stage. [ABSTRACT FROM AUTHOR]

Abstract Background A challenge in human mammary epithelial cell (HMEC) culture is sustaining the representation of competing luminal, myoepithelial, and progenitor lineages over time. As cells replicate in culture, myoepithelial cells come to dominate the composition of the culture with serial passaging. This drift in composition presents a challenge for studying luminal and progenitor cells, which are prospective cells of origin for most breast cancer subtypes. Methods We demonstrate the use of postconfluent culture on HMECs. Postconfluent culture entails culturing HMECs for 2–5 weeks without passaging but maintaining frequent feedings in low-stress M87A culture medium. In contrast, standard HMEC culture entails enzymatic subculturing every 3–5 days to maintain subconfluent density. Results When compared to standard HMEC culture, postconfluent culture yields increased proportions of luminal cells and c-Kit+ progenitor cells. Postconfluent cultures develop a distinct multilayered morphology with individual cells showing decreased physical deformability as compared to cells in standard culture. Gene expression analysis of postconfluent cells shows increased expression of lineage-specific markers and extracellular matrix components. Conclusions Postconfluent culture is a novel, useful strategy for altering the lineage composition of HMECs, by increasing the proportional representation of luminal and progenitor cells. We speculate that postconfluent culture creates a microenvironment with cellular composition closer to the physiological state and eases the isolation of scarce cell subtypes. As such, postconfluent culture is a valuable tool for researchers using HMECs for breast cancer research.

Abstract Background Gastrointestinal stromal tumor (GIST) is a malignant mesenchymal neoplasm described in humans, dogs, and cats. A hallmark of diagnosis for GISTs is positive immunohistochemical labelling with c-Kit (CD117). The differentiation of GIST from other mesenchymal neoplasms of the gastrointestinal tract is pivotal to allow for initiation of appropriate treatment. In humans, cystic GIST has been described, though this has not been reported in dogs. In humans, the cystic form of GIST has been associated with a favorable prognosis. In the present paper, we report a case of multilocular cystic GIST in a dog, which has not previously been described in this species. Case presentation A ten-year-old, male-entire Maltese terrier mix breed dog presented with a large cystic mural mass of the duoedenum and orad jejunum. Histopathology and positive immunohistochemical staining with CD117 confirmed a diagnosis of GIST. No evidence of metastasis was detected on routine staging with abdominal sonography and thoracic radiography at the time of diagnosis. Surgical resection was performed and toceranib therapy was initiated post-operatively. Metastasis was documented 251 days after surgery on computed tomography. Due to clinical deterioration, the patient was humanely euthanised 370 days after surgical excision. Conclusions There are few differential diagnoses for large multilocular cystic intra-abdominal masses in dogs. This case presents a previously undescribed presentation of gastrointestinal stromal tumor in the dog as a predominantly multilocular cystic mass. It remains unclear if the cystic form of GIST may represent a favorable prognosis in dogs.

Prognosis of patients with acute myeloid leukemia receiving intensive chemotherapy is defined as kariotyping anomalies, and mutations of genes responsible for surviving and self-maintenance leukemic cells. In the giving work incidence of mutation involving genes FLT3, c-KIT, NPM1 having prognostic value in adults is analysed. Kynase domain FLT3 mutation in 18 from 83 patients (21.6%) was detected. 2 from 18 patients (11%) achieved complete remission, 5 from 18 patients (27.7%) with FLT3 mutations were refractory to therapy, two patients died from treatment complications, 9 from 18 (50%) relapsed. Only 2 patients (11%) are alive in continuous complete remission. с-KIT mutations detected in 14.2% (2/14 patients), and NPM1 mutations represented allelic polymorphism. Thus, kynase domain FLT3 mutation are prognostic unfavorable.

Corebinding factor acute myeloid leukemia (CBF-AML) is the most common cytogenetic subtype of pediatric AML. CBF-AML is associated with a relatively favorable outcome, although the relapse rate of approximately 40% indicates a high degree of clinical heterogeneity. The clinical impact of additional cytogenetic aberrations, including c-KIT and CEBPA mutations, in pediatric CBF-AML has not been well characterized, especially in the multi-ethnic region of Yunnan Province in China. In this study, we retrospectively analyzed the clinical features, gene mutations, and prognoses of 72 pediatric patients newly diagnosed with non-M3 AML in Kunming Children's Hospital, China, from January 1, 2015 to May 31, 2020. Of the 72 pediatric patients with AML, 46% (33/72) had CBF-AML. Thirteen patients with CBF-AML (39%) had c-KIT mutations, five (15%) had CEBPA mutations, and eleven (33.3%) had no other cytogenetic aberrations. The c-KIT mutations, resulting from single nucleotide substitutions and small insertions or deletions, occurred in exons 8 and 17. All of the CBF-AML-associated CEBPA mutations were single mutations and occurred in patients with RUNX1-RUNX1T1 fusion. We found no significant differences in the clinical data between CBF-AML patients with c-KIT or CEBPA mutations and CBF-AML patients without other aberrations, and no prognostic significance was established for these mutations. Our study is the first to report the clinical impact of c-KIT and CEBPA mutations in pediatric patients with non-M3 CBF-AML from the multi-ethnic Yunnan Province, China. c-KIT and CEBPA mutations occurred at a higher frequency in CBF-AML cases and were associated with unique clinical characteristics; however, no potential molecular prognostic markers were identified. [ABSTRACT FROM AUTHOR]

Mast cells are leukocytes that mediate various aspects of immunity and drive allergic hypersensitivity pathologies. Mast cells differentiate from hematopoietic progenitor cells in a manner that is largely IL-3 dependent. However, molecular mechanisms, including the signaling pathways that control this process, have yet to be thoroughly investigated. Here, we examine the role of the ubiquitous and critical mitogen-activated protein kinase signaling pathway due to its position downstream of the IL-3 receptor. Hematopoietic progenitor cells were harvested from the bone marrow of C57BL/6 mice and differentiated to bone marrow–derived mast cells in the presence of IL-3 and mitogen-activated protein kinase inhibitors. Inhibition of the JNK node of the mitogen-activated protein kinase pathway induced the most comprehensive changes to the mature mast cell phenotype. Bone marrow–derived mast cells differentiated during impaired JNK signaling expressed impaired c-kit levels on the mast cell surface, first detected at week 3 of differentiation. Following 1 wk of inhibitor withdrawal and subsequent stimulation of IgE-sensitized FcεRI receptors with allergen (TNP-BSA) and c-kit receptors with stem cell factor, JNK-inhibited bone marrow–derived mast cells exhibited impediments in early-phase mediator release through degranulation (80% of control), as well as late-phase secretion of CCL1, CCL2, CCL3, TNF, and IL-6. Experiments with dual stimulation conditions (TNP-BSA + stem cell factor or TNP-BSA alone) showed that impediments in mediator secretion were found to be mechanistically linked to reduced c-kit surface levels. This study is the first to implicate JNK activity in IL-3–mediated mast cell differentiation and also identifies development as a critical and functionally determinative period. [ABSTRACT FROM AUTHOR]

The proto-oncogenic protein, c-KIT, plays a crucial role in regulating cellular transformation and differentiation processes, such as proliferation, survival, adhesion, and chemotaxis. The overexpression of, and mutations, in c-KIT can lead to its dysregulation and promote various human cancers, particularly gastrointestinal stromal tumors (GISTs); approximately 80–85% of cases are associated with oncogenic mutations in the KIT gene. Inhibition of c-KIT has emerged as a promising therapeutic target for GISTs. However, the currently approved drugs are associated with resistance and significant side effects, highlighting the urgent need to develop highly selective c-KIT inhibitors that are not affected by these mutations for GISTs. Herein, the recent research efforts in medicinal chemistry aimed at developing potent small-molecule c-KIT inhibitors with high kinase selectivity for GISTs are discussed from a structure–activity relationship perspective. Moreover, the synthetic pathways, pharmacokinetic properties, and binding patterns of the inhibitors are also discussed to facilitate future development of more potent and pharmacokinetically stable small-molecule c-KIT inhibitors. [ABSTRACT FROM AUTHOR]

Simple Summary: In veterinary medicine, methods such as histological grading, immunohistochemistry and mutation analysis of the c-kit gene are tools to assess the prognosis and treatment of canine cutaneous mast cell tumours. These methods have not yet been applied and evaluated on a large scale for mast cell tumours of the dog's toe, as these digital mast cell tumours are considered a subset of the cutaneous forms. Mast cell tumours can be more aggressive at certain sites. Therefore, the aim of this study was to apply these methods to 68 dogs with digital mast cell tumours. Even though only a few digital mast cell tumours were histologically poorly differentiated, more than half had immunohistochemical findings that could indicate an unfavourable prognosis. Mutations in the c-kit gene were found as well. Moreover, French Bulldogs—a breed that tends to develop benign variants at other sites on the skin—were more likely to have poorly differentiated tumours. Although outcome data were not available, the results of this study may contribute to a better understanding of canine mast cell tumours of the toe. Grading, immunohistochemistry and c-kit mutation status are criteria for assessing the prognosis and therapeutic options of canine cutaneous mast cell tumours (MCTs). As a subset, canine digital MCTs have rarely been explored in this context. Therefore, in this retrospective study, 68 paraffin-embedded canine digital MCTs were analysed, and histological grading was assessed according to Patnaik and Kiupel. The immunohistochemical markers KIT and Ki67 were used, as well as polymerase chain reaction (PCR) for mutational screening in c-kit exons 8, 9, 11 and 14. Patnaik grading resulted in 22.1% grade I, 67.6% grade II and 10.3% grade III tumours. Some 86.8% of the digital MCTs were Kiupel low-grade. Aberrant KIT staining patterns II and III were found in 58.8%, and a count of more than 23 Ki67-positive cells in 52.3% of the cases. Both parameters were significantly associated with an internal tandem duplication (ITD) in c-kit exon 11 (12.7%). French Bulldogs, which tend to form well-differentiated cutaneous MCTs, had a higher proportion of digital high-grade MCTs and ITD in c-kit exon 11 compared with mongrels. Due to its retrospective nature, this study did not allow for an analysis of survival data. Nevertheless, it may contribute to the targeted characterisation of digital MCTs. [ABSTRACT FROM AUTHOR]

We investigated the entire length of the main excretory ducts (MED) of the major sublingual, parotid and submandibular salivary glands of mature laboratory rats for mucous (goblet) and luminal ciliated cells, biomarkers of cell proliferation, apoptosis, and five biomarkers of stem cells. Spleen and testis were used as positive controls. We used formalin fixed, paraffin embedded tissues. No mucous cells or cells with luminal cilia were observed in hematoxylin and eosin, alcian blue or periodic acid-Schiff stained sections. Immunohistochemistry using rabbit anti-rat antibodies produced anomalous reactions with cleaved caspase-3 for apoptosis, Ki-67 for proliferative activity and Sox 2. Following antigen retrieval, no primary antibody and all three negative controls, labeled macrophages appeared in the spleen. TUNEL staining revealed a few cells per section undergoing apoptosis. Reactions deemed valid occurred in MED with cytokeratin-5 and c-Kit and stem cell antigen 1 (Sca-1) mostly in the gland and middle segments. Other ducts, but not acini or myoepithelial cells, also were variably stained with c-Kit and Sca-1. [ABSTRACT FROM AUTHOR]

In patients with an ascending aorta aneurysm, restructuring of all its layers and, first of all, the intima and media was revealed. The thickness of the intima was 79.3±63.1 μm in patients with aortic diameter <55 mm (group Ao<55) and 162.7±177.4 μm (p<0.05) in patients with aortic diameter ⩾55 mm (Ao⩾55 group), the thickness of the aortic media was 1184.0±198.2 and 1144.3±288.4 μm, respectively. In patients of the Ao<55 group, aortic dilatation was accompanied by compensatory thickening of the inner and middle layers of the aorta. In the Ao⩾55 group, thinning of the aortic media, fragmentation of elastic fibers, and its cystic degeneration were revealed. c-kit+ Stem cells were detected in the subendothelium of the thickened intima of the dilated ascending aorta. The appearance of c-kit+ cells correlated with intimal remodeling and its colonization with CD34+ and CD44+ myofibroblast-like cells. [ABSTRACT FROM AUTHOR]

Enhancing cardiomyocyte survival is crucial to blunt deterioration of myocardial structure and function following pathological damage. PIM1 (Proviral Insertion site in Murine leukemia virus (PIM) kinase 1) is a cardioprotective serine threonine kinase that promotes cardiomyocyte survival and antagonizes senescence through multiple concurrent molecular signaling cascades. In hematopoietic stem cells, PIM1 interacts with the receptor tyrosine kinase c-Kit upstream of the ERK (Extracellular signal-Regulated Kinase) and Akt signaling pathways involved in cell proliferation and survival. The relationship between PIM1 and c-Kit activity has not been explored in the myocardial context. This study delineates the interaction between PIM1 and c-Kit leading to enhanced protection of cardiomyocytes from stress. Elevated c-Kit expression is induced in isolated cardiomyocytes from mice with cardiac-specific overexpression of PIM1. Co-immunoprecipitation and proximity ligation assay reveal protein-protein interaction between PIM1 and c-Kit. Following treatment with Stem Cell Factor, PIM1-overexpressing cardiomyocytes display elevated ERK activity consistent with c-Kit receptor activation. Functionally, elevated c-Kit expression confers enhanced protection against oxidative stress in vitro. This study identifies the mechanistic relationship between PIM1 and c-Kit in cardiomyocytes, demonstrating another facet of cardioprotection regulated by PIM1 kinase.