Src Kinase Research Articles

Circ_0060967 contributes to colorectal cancer progression by sponging miR-1184 to up-regulate SRC proto-oncogene

Background and study aimsCircular RNAs (circRNAs) are closely associated with cancer pathogenesis. The purpose of our current study was to explore the role and mechanism of circ_0060967 in colorectal cancer (CRC) development. Patients and methodsHuman CRC specimens and paired healthy tissues were used to examine variable expression. The expression of circ_0060967 and microRNA (miR)-1184 was examined by quantitative reverse transcription-PCR. The protein levels of proliferating cell nuclear antigen, BCL2-associated X, apoptosis regulator (Bax), proto-oncogene nonreceptor tyrosine kinase Src (SRC), nuclear factor-κB inhibitor alpha (IκBα), phosphorylated-IκBα (p-IκBα), RELA proto-oncogene, nuclear factor-κB subunit (p65), and phosphorylated-p65 (p-p65) were determined by western blot. Proliferation and motility of HCT-116 and SW480 CRC cells were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and transwell assays, respectively. Dual-luciferase reporter assay and RNA immunoprecipitation assay were used to determine the binding relation between miR-1184 and circ_0060967 or SRC. Animal studies were used to detect the role of circ_0060967 in CRC cell tumorigenicity. ResultsCirc_0060967 abundance was enhanced in human CRC tissue samples versus paired normal colorectal tissues and in HCT-116 and SW480 CRC cells versus normal HCO cells. Decreased expression of circ_0060967 could suppress cell growth, motility, and invasiveness of CRC cells in vitro and tumor growth in vivo. Circ_0060967 sponged miR-1184, and miR-1184 targeted SRC. Furthermore, we also found circ_0060967 affected cell growth by modulating miR-1184/SRC axis in CRC. ConclusionThis study demonstrates a novel circ_0060967/miR-1184/SRC regulatory cascade in affecting CRC cell malignant behaviors, which can have a broad effect on the field of molecularly targeted therapeutics.

THY1 (CD90) Maintains the Adherens Junctions in Nasopharyngeal Carcinoma via Inhibition of SRC Activation

We had previously shown that THY1 (CD90) is a tumor suppressor in nasopharyngeal carcinoma (NPC) and that its down-regulation and loss of expression are associated with tumor metastasis, yet the mechanism leading to such effects remains unknown. In this study we show that tumor invasion could be suppressed by THY1 via adherens junction formation in a few NPC cell lines, and knockdown of THY1 would disrupt this cell-cell adhesion phenotype. Mechanistically, the activity of the SRC family kinase (SFK) member, SRC, and canonical Wnt signaling were dramatically reduced when THY1 was constitutively expressed. Previous studies by others have found that high levels of SRC activity in NPCs are associated with EMT and a poor prognosis. We hypothesized that THY1 can suppress tumor invasion in NPC via inhibition of SRC. By gene silencing of SRC, we found that the in vitro NPC cell invasion was significantly reduced and adherens junctions were restored. Through proteomic analysis, we identified that platelet-derived growth factor receptor β (PDGF-Rβ) and protein tyrosine phosphatase nonreceptor type 22 (PTPN22) are novel and potential binding partners of THY1, which were subsequently verified by co-immunoprecipitation (co-IP) analysis. The ligand of PDGF-Rβ (PDGF-BB) could highly induce SRC activation and NPC cell invasion, which could be almost completely suppressed by THY1 expression. On the other hand, the PTPN22 siRNA could enhance both the SRC activities and the cell invasion and could also disrupt the adherens junctions in the THY1-expressing NPC cells; the original THY1-induced phenotypes were reverted when the PTPN22 expression was reduced. Together, our results identified that PTPN22 is essential for THY1 to suppress cell invasion and SRC activity, maintain tight adherens junctions, and prevent NPC metastasis. These results suggested that PDGF-Rβ and SRC can be used as drug targets for suppressing NPC metastasis. Indeed, our in vivo assay using the SRC inhibitor KX2-391, clearly showed that inhibition of SRC signaling can prevent the metastasis of NPC, indicating that targeting SRC can be a promising approach to control the NPC progression.

Abstract 3620: N-myristoylation inhibition reduces angiogenesis and cancer cell migration

Abstract Myristoylation is the modification of proteins by the 14-carbon fatty acid myristate. In humans, two N-myristoyltransferases (NMT1 and NMT2) catalyze myristate transfer onto >200 proteins to regulate membrane binding and signal transduction. The pan-NMT inhibitor PCLX-001 has been in phase I clinical trials over a year for the treatment of lymphoma and advanced solid malignancies. Lack of myristoylation promotes the degradation of numerous normally myristoylated proteins like the proto-oncogenic Src family kinases (SFKs). SFKs like Src and Lyn are essential for downstream signaling of Vascular Endothelial Growth Factor (VEGF) and Epidermal Growth Factor (EGF) receptor tyrosine kinases. Thus, SFKs are critical for angiogenesis and cell motility. Angiogenesis is essential for tumor growth and dissemination of cancer cells to distal locations. VEGF-induced angiogenesis requires Src activation, suggesting that PCLX-001 may have antiangiogenic properties. SFKs also promote cell migration/metastasis, the leading cause of cancer-associated mortality. Lyn SFK knockdown was shown to reduce breast cancer migration and neighbouring tissue invasion, suggesting that PCLX-001 may also inhibit cell migration/metastasis. We investigated the antiangiogenic properties of PCLX-001 in vitro using HUVEC umbilical cord cells. PCLX-001 treatment significantly reduced HUVEC sprouting and tube-formation to levels lower than two FDA-approved angiogenesis inhibitors Sorafenib and Sunitinib. PCLX-001 also significantly reduced neo-vascularisation in vivo at lower concentrations than these two drugs using a chicken chorioallantoic membrane model, demonstrating the high potential of myristoylation inhibitors to reduce angiogenesis. We then validated our observations in vivo using a HT-1376 bladder mouse xenograft model. Tumors from mice treated for 28 days at increasing PCLX-001 concentrations showed significant reduction of Src, Lyn, and VEGF receptor protein levels as measured by immunohistochemistry, further validating PCLX-001 effect in vivo. We hypothesize that PCLX-001 acts downstream of VEGF/EGF receptors by inducing degradation of un-myristoylated SFKs. We confirmed this by knocking down NMT1 or treating breast cancer cells with PCLX-001 and found that both significantly reduced SFK protein levels. In a wound-healing assay using PCLX-001, we observed significant dose-dependent cell migration inhibition. PCLX-001 also dose-dependently reduced migration and invasion in transwell migration/invasion assays, indicating that myristoylation is required for optimal migration and potentially cancer cell metastasis. Overall, by lowering SFK levels, PCLX-001 reduces angiogenesis, cell migration/invasion, and thus potentially cancer metastasis. Reducing these classical cancer hallmarks in malignant cells may benefit a wide array of cancer patients and ultimately improve cancer treatment outcomes. Citation Format: Rony Pain, Erwan Beauchamp, Katia Carmine-Simmen, Jay Gamma, Rebecca Reif, Abul Azad, Allan Murray, John Lewis, Luc Berthiaume. N-myristoylation inhibition reduces angiogenesis and cancer cell migration. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3620.

Abstract 4876: A systems pharmacology approach to discover synergistic targeted therapy combinations

Abstract The discovery of oncogenic signal transduction in cancer has enabled the development and clinical use of dozens of kinase-directed targeted therapies, but patient response is often transient and resistance invariably develops. In the setting of BRAF-mutant melanoma, for instance, a majority of patients relapse within one year of initiating targeted therapy. Combination therapies blocking compensatory signaling pathways provide a strategy for boosting treatment efficacy and delaying resistance. To find synergistic kinase inhibitor combinations, we used a multimodal systems pharmacology approach to quantify the early adaptive signaling and gene regulatory dynamics in patient-derived BRAFV600E-mutant melanoma cells under oncogene inhibition. Cells were treated with vemurafenib or vehicle and sampled longitudinally at timepoints spanning minutes to days. To measure signaling dynamics, thousands of protein phosphorylation sites covering commonly altered signaling axes in cancer were motif-enriched by immunoprecipitation, barcoded with isobaric tandem mass tags (TMT), and quantified by high-resolution mass spectrometry (MS). The resulting time-resolved phosphoproteomics data showed rapid (<15 minutes) and potent (>8-fold) downregulation of ERK1/2, confirming strong BRAF inhibition. Statistical integration of signaling measurements with time-series RNA-seq data collected at the same timepoints enabled reconstruction of multi-scale regulatory networks governing the adaptive response to oncogene inhibition. In particular, we observed early induction of SRC-family kinase (SFK) signaling and a broad cytoskeletal signaling module, implicating a compensatory prosurvival signaling program. The induction intensified over the 3-day treatment window and was fully reversed following a 6-day drug holiday, suggesting a reversible nature of drug adaptation. Immunoblotting confirmed sustained loss of ERK1/2 activity and concomitant elevated SFK phosphorylation following drug treatment. Accumulation of reactive oxygen species, a known activator of SFKs, strongly correlated with SFK activity, and both were ablated following treatment with the antioxidant precursor N-acetylcysteine. This adaptive response predicted a significant degree of synergy between vemurafenib and the pan-SFK inhibitor dasatinib, which was validated in a panel of patient-derived melanoma cell lines and in melanoma xenograft mouse models. Targeted MS of phospho-ERK1/2 and canonical SFK substrates, including CTTN, PXN, and PAG1, validated the mechanism of action of this combination. Complementary data from patient-derived non small-cell lung cancer (NSCLC) cells under tyrosine kinase inhibitor treatment demonstrates the generality of our integrative approach, and supports the notion that SFK activation may be a hallmark response to oncogenic RTK-RAS-ERK pathway inhibition. Citation Format: Cameron T. Flower, Chunmei Liu, James R. Heath, Wei Wei, Forest M. White. A systems pharmacology approach to discover synergistic targeted therapy combinations. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4876.

Enhanced Lyn Activity Causes Severe, Progressive Emphysema and Lung Cancer.

The epidemiological patterns of incident chronic obstructive pulmonary disease (COPD) and lung adenocarcinoma are changing, with an increasing fraction of disease occurring in patients who are never-smokers or were not exposed to traditional risk factors. However, causative mechanism(s) are obscure. Overactivity of Src family kinases (SFKs) and myeloid cell-dependent inflammatory lung epithelial and endothelial damage are independent candidate mechanisms, but their pathogenic convergence has not been demonstrated. Here we present a novel preclinical model in which an activating mutation in Lyn, a nonreceptor SFK that is expressed in immune cells, epithelium, and endothelium-all strongly implicated in the pathogenesis of COPD-causes spontaneous inflammation, early-onset progressive emphysema, and lung adenocarcinoma. Surprisingly, even though activated macrophages, elastolytic enzymes, and proinflammatory cytokines were prominent, bone marrow chimeras formally demonstrated that myeloid cells were not disease initiators. Rather, lung disease arose from aberrant epithelial cell proliferation and differentiation, microvascular lesions within an activated endothelial microcirculation, and amplified EGFR (epidermal growth factor receptor) expression. In human bioinformatics analyses, LYN expression was increased in patients with COPD and was correlated with increased EGFR expression, a known lung oncogenic pathway, and LYN was linked to COPD. Our study shows that a singular molecular defect causes a spontaneous COPD-like immunopathology and lung adenocarcinoma. Furthermore, we identify Lyn and, by implication, its associated signaling pathways as new therapeutic targets for COPD and cancer. Moreover, our work may inform the development of molecular risk screening and intervention methods for disease susceptibility, progression, and prevention of these increasingly prevalent conditions.

Abstract 1662: Understanding the sensitivity of cancer cells to myristoylation inhibitors for oncology applications

Abstract PCLX-001 is a first-in-kind drug that targets a protein modification essential for membrane anchorage and signalling, and has been under human clinical trial evaluation for the treatment of lymphoma and solid malignancies for over a year. In human, over 600 proteoforms are modified with the fatty acid myristate by two N-myristoyltransferases: NMT1 and NMT2. These include many proto-oncogenic proteins (e.g. Src-family kinases and c-Abl) and metabolic regulators (e.g. AMPK β subunit). Thus, we validated the potential of NMTs as oncology targets on 300 cancer cell lines and uncovered its potential in hematological cancers. The multiple substrates of NMTs complicated the elucidation of a clear mechanism of action of the pan-NMT inhibitor PCLX-001. To circumvent this, we evaluated the individual roles of NMT1 and NMT2 in tumours as well as their relative contributions, including those of their substrates, to PCLX-001 sensitivity. Analysis of TCGA and CCLE databases revealed that NMT2 expression levels vary drastically (7 log2(TPM+1)) while those of NMT1 vary slightly (3 log2(TPM+1)). Hematological cancers comprised the vast majority of the lowest NMT2 expressing cells but lower NMT2 levels were also observed in solid tumour cell lines (e.g. breast & ovary). NMT2 levels were also lower in cancer versus normal corresponding tissues. We confirmed that NMT2 expression is epigenetically repressed at a CpG island found in the 5´end of the NMT2 gene thereby explaining the reduction in NMT2 expression. Since most hematological cancer cells are NMT2-deficient, we think that by targeting the remaining NMT1, PCLX-001 selectively kills these cells in a manner reminiscent of synthetic lethality, thereby sparing normal human cells with two NMTs. Therefore, identifying substrates specific to NMT1 in NMT2-deficient cancer cells became of the utmost importance to understand which NMT1 protein substrates were critical for survival. Using differential proteomics in the CRISPR/Cas9 NMT1 KO HAP1 near-haploid cell line derived from the chronic myelogenous leukemia versus WT HAP1 cells, we surprisingly found that few signaling proteins were downregulated, rather, 36 mitochondrial protein levels were decreased and 18 of these belonged to respiratory complex I. Myristoylated mitochondrial protein NDUFAF4, a major complex I assembly factor, was the most downregulated and PCLX-001 reduced its levels leading to decreased complex I activity. This seemingly ordinary observation could have transformational implications for cancer treatment since oxidative phosphorylation is essential for both cancer stem cell survival and metastasis. In addition, gene set enrichment analyses performed on RNASeq data obtained from 1200 cell lines treated with myristoylation inhibitors allowed us to derive an NMT inhibition sensitivity gene set that could be used to identify patients which would most benefit from NMT inhibition therapy. Citation Format: Erwan Beauchamp, Chistopher Cromwell, Eman Moussa, Aishwarya Iyer, Megan Yap, Rony Pain, Jay Gamma, Olivier Julien, Basil Hubbard, Luc Berthiaume. Understanding the sensitivity of cancer cells to myristoylation inhibitors for oncology applications [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1662.

Abstract 1727: Cytoplasmic EZH2 and the DLC1 tumor suppressor are regulated by the CRM1 nuclear export protein and by specific complex formation between mutant KRAS and RAN-GAP

Abstract The DLC1 tumor suppressor gene encodes a cytoplasmic RHO-GAP protein whose expression is frequently decreased in many cancer types, especially lung cancer. We have identified several cancer-associated post-translational modifications in the DLC1 protein that decrease its tumor suppressor activity and are exploring the upstream mechanisms that regulate the changes as well as the therapeutic potential of reactivating the tumor suppressor activity of DLC1 by inhibiting the post-translational changes. We have made the unexpected observation that lung cancer expresses increased levels of EZH2 in the cytoplasm, where it can methylate DLC1, which can trigger the ubiquitin-proteasomal-dependent degradation of DLC1. The cytoplasmic EZH2 is derived from the nucleus, and inhibition of the CRM1 nuclear export protein or the EZH2 methyl transferase activity can drastically reduce the level of cytoplasmic EZH2 or its activity, which increases the half-life and steady-state level of DLC1 protein several fold. The stabilized DLC1 protein can be reactivated by inhibiting the AKT and SRC kinases, whose phosphorylation of DLC1 can attenuate its tumor suppressor function. A three-drug combination of an EZH2 or a CRM1 inhibitor, together with AKT and SRC kinase inhibitors, can greatly reduce the weight of tumor xenografts from human lung cancer cell lines and induce markers of apoptosis and senescence. Remarkably, isogenic knock-out of DLC1 abolishes most of the anti-tumor activity, implying that DLC1 is the main target of the three-drug treatment, although each inhibitor has many other targets. In addition, we have found that inhibiting endogenous mutant KRAS in the lung cancer lines can phenocopy the CRM1 inhibitor, leading to loss of cytoplasmic EZH2 and increasing the level of DLC1 protein. Conversely, mutant KRAS increases the level of cytoplasmic EZH2 and decreases DLC1. We have investigated the underlying mechanism, and have determined that mutant KRAS regulates nucleocytoplasmic protein shuttling by forming a previously unidentified complex with RAN-GAP (present in primary human tumors and cell lines), which regulates the RAN GTPase, a protein that is required for other proteins to shuttle from the cytoplasm to the nucleus and from the nucleus to the cytoplasm. Formation of the RAS/RAN-GAP complex and its downstream consequences are independent of known RAS signaling from the plasma membrane, as inhibition of MAPK and PI3K does not affect this process. However, efficient complex formation does depend on farnesylation of RAS, as farnesylation-deficient mutants form the complex less efficiently and have reduced consequences for EZH2 and DLC1. Thus, we have identified nucleocytoplasmic protein shuttling as a new function for mutant KRAS and have determined the mechanism depends on complex formation between KRAS and RAN-GAP. Citation Format: Brajendra Tripathi, Nicole Hirsh, David Hansen, Xiaolan Qian, Dunrui Wang, Marian E. Durkin, Ashley Lim, Alex G. Papageorge, Suresh S. Ramalingham, Adam I. Marcus, Douglas R. Lowy. Cytoplasmic EZH2 and the DLC1 tumor suppressor are regulated by the CRM1 nuclear export protein and by specific complex formation between mutant KRAS and RAN-GAP [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1727.

Abstract 3616: Investigating proto-oncogene PBF-induced cell migration and invasion

Abstract The proto-oncogene pituitary tumor transforming gene binding factor (PTTG1IP/PBF) is overexpressed in multiple tumors and associated with tumor progression. PBF mediates several tumorigenic processes, including cell motility, whereby it potently induces cancer cell migration and invasion. PBF is phosphorylated by Src kinase at Y174 and mutation of this residue (Y174A) renders PBF unable to induce cell invasion, suggesting that phosphorylation mediates the stimulation of cancer cell motility by PBF. This study aimed to further elucidate the mechanism of PBF-induced cell motility. PBF-Y174 is also the key residue in a YXXΦ endocytosis motif. Both PBF phosphorylation and endocytosis were found to be essential for PBF-induced cell motility as mutants which disrupted either process were unable to stimulate thyroid and breast cancer cell migration and invasion. To elucidate molecular events downstream of PBF overexpression, phosphoproteomic and RNA-Seq analyses of normal thyroid cells (Nthy-ori 3-1) with stable PBF overexpression were performed and showed an enrichment in molecules involved in cell adhesion and cytoskeleton organisation. These findings prompted further investigation into a physiological role for PBF in cell motility. We utilised a novel Pbf knockout (Pbf−/−) mouse model generated through CRISPR/Cas9-mediated deletion of Pbf exon 4 in C57BL/6N mice to determine the impact of Pbf deletion on cellular mechanisms. Mouse embryonic fibroblasts (MEFs) were isolated at embryonic day 13.5 and used as primary cultures. Pbf−/- MEFs showed a significant reduction in migration and invasion compared with wild-type (Pbf+/+) MEFs. Interestingly, the loss of one functional copy of Pbf in heterozygote MEFs (Pbf+/−) resulted in an intermediate decrease in motility suggesting a gene-dosage effect. Initial immunofluorescent studies of Pbf−/− MEFs suggest alterations in focal adhesions (FAs). In Pbf+/+ MEFs focal adhesion kinase (FAK) and paxillin staining highlighted FA structures that were normally elongated and aligned with actin stress fibers. In contrast, Pbf−/- MEFs demonstrated a significant reduction in FAK and paxillin staining with smaller, punctate and more radially distributed FAs. These studies demonstrate a physiological role for PBF in cell adhesion and migration and further elucidate the mechanism by which PBF induces cell motility in tumor progression. Citation Format: Merve Kocbiyik, Selvambigai Manivannan, Ling Zha, Katie Brookes, Martin L Read, Chris J McCabe, Vicki E Smith. Investigating proto-oncogene PBF-induced cell migration and invasion. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3616.

Coordinated activation of c-Src and FOXM1 drives tumor cell proliferation and breast cancer progression.

Activation of the tyrosine kinase c-Src promotes breast cancer progression and poor outcomes, yet the underlying mechanisms are incompletely understood. Here, we have shown that deletion of c-Src in a genetically engineered model mimicking the luminal B molecular subtype of breast cancer abrogated the activity of forkhead box M1 (FOXM1), a master transcriptional regulator of the cell cycle. We determined that c-Src phosphorylated FOXM1 on 2 tyrosine residues to stimulate its nuclear localization and target gene expression. These included key regulators of G2/M cell-cycle progression as well as c-Src itself, forming a positive feedback loop that drove proliferation in genetically engineered and patient-derived models of luminal B-like breast cancer. Using genetic approaches and small molecules that destabilize the FOXM1 protein, we found that targeting this mechanism induced G2/M cell-cycle arrest and apoptosis, blocked tumor progression, and impaired metastasis. We identified a positive correlation between FOXM1 and c-Src expression in human breast cancer and show that the expression of FOXM1 target genes predicts poor outcomes and associates with the luminal B subtype, which responds poorly to currently approved therapies. These findings revealed a regulatory network centered on c-Src and FOXM1 that is a targetable vulnerability in aggressive luminal breast cancers.

Lyn attenuates sepsis-associated acute kidney injury by inhibition of phospho-STAT3 and apoptosis

Sepsis-associated acute kidney injury (SA-AKI) is a life-threatening condition associated with high mortality and morbidity. However, the underlying pathogenesis of SA-AKI is still unclear. Lyn belongs to Src family kinases (SFKs), which exert numerous biological functions including modulation in receptor-mediated intracellular signaling and intercellular communication. Previous studies demonstrated that Lyn gene deletion obviously aggravates LPS-induced lung inflammation, but the role and possible mechanism of Lyn in SA-AKI have not been reported yet. Here, we found that Lyn protected against renal tubular injury in cecal ligation and puncture (CLP) induced AKI mouse model by inhibition of signal transducer and activator of transcription 3 (STAT3) phosphorylation and cell apoptosis. Moreover, Lyn agonist MLR-1023 pretreatment improved renal function, inhibited STAT3 phosphorylation and decreased cell apoptosis. Thus, Lyn appears to play a crucial role in orchestrating STAT3-mediated inflammation and cell apoptosis in SA-AKI. Hence, Lyn kinase may be a promising therapeutic target for SA-AKI.

Characterization of "Off-Target" Immune Modulation Induced by Live Attenuated Yellow Fever Vaccine.

Live attenuated vaccines alter immune functions and are associated with beneficial outcomes. We previously demonstrated that live attenuated yellow fever virus (YFV) vaccine (LA-YF-Vax) dampens T-cell receptor (TCR) signaling in vitro via an RNA-based mechanism. We examined study participants before and after LA-YF-Vax to assess TCR-mediated functions in vivo. Serum samples and peripheral blood mononuclear cells (PBMCs) were obtained before and after LA-YF-Vax (with or without additional vaccines) or quadrivalent influenza vaccine. TCR-mediated activation was determined by interleukin 2 release or phosphorylation of the lymphocyte-specific Src kinase. TCR-regulating phosphatase (protein tyrosine phosphatase receptor type E [PTPRE]) expression was also measured. Compared with prevaccination findings, LA-YF-Vax recipient PBMCs demonstrated transient reduction in interleukin 2 release after TCR stimulation and PTPRE levels, unlike in control participants who received quadrivalent influenza vaccine. YFV was detected in 8 of 14 participants after LA-YF-Vax. After incubation of healthy donor PBMCs in serum-derived extracellular vesicles prepared from LA-YF-Vax recipients, TCR signaling and PTPRE levels were reduced after vaccination, even in participants without detectable YFV RNA. LA-YF-Vax reduces TCR functions and PTPRE levels after vaccination. Extracellular vesicles from serum recapitulated this effect in healthy cells. This likely contributes to the reduced immunogenicity for heterologous vaccines after LA-YF-Vax administration. Identification of specific immune mechanisms related to vaccines should contribute to understanding of the "off-target," beneficial effects of live vaccines.

Src inhibition induces mitotic arrest associated with chromosomal passenger complex.

The non-receptor tyrosine kinase Src plays a key role in cell division, migration, adhesion, and survival. Src is overactivated in several cancers, where it transmits signals that promote cell survival, mitosis, and other important cancer hallmarks. Src is therefore a promising target in cancer therapy, but the underlying mechanisms are still uncertain. Here we show that Src is highly conserved across different species. Src expression increases during mitosis and is localized to the chromosomal passenger complex. Knockdown or inhibition of Src induces multipolar spindle formation, resulting in abnormal expression of the Aurora B and INCENP components of the chromosomal passenger complex. Molecular mechanism studies have found that Src interacts with and phosphorylates INCENP. This then leads to incorrect chromosome arrangement and segregation, resulting in cell division failure. Herein, Src and chromosomal passenger complex co-localize and Src inhibition impedes mitotic progression by inducing multipolar spindle formation. These findings provide novel insights into the molecular basis for using Src inhibitors to treat cancer.

Nanohydroxyapatite-Coated Titanium Surface Increases Vascular Endothelial Cells Distinct Signaling Responding to High Glucose Concentration.

The success of dental implants depends on osseointegration can be compromised by well-known related adverse biological processes, such as infection and diabetes. Previously, nanohydroxyapatite-coated titanium surfaces (nHA_DAE) have been shown to contain properties that promote osteogenesis by enhancing osteoblast differentiation. In addition, it was hypothesized to drive angiogenesis in high-glucose microenvironments, mimicking diabetes mellitus (DM). On the other hand, the null hypothesis would be confirmed if no effect was observed in endothelial cells (ECs). Titanium discs presenting the differential surfaces were previously incubated in an FBS-free cell culture medium for up to 24 h, which was, thereafter, supplemented with 30.5 mM of glucose to expose human umbilical vein endothelial cells (HUVECs, ECs) for 72 h. They were then harvested, and the sample was processed to provide molecular activity of specific genes related to EC survival and activity by using qPCR, and the conditioned medium by ECs was used to evaluate the activity of matrix metalloproteinases (MMPs). Our data guaranteed better performance of this nanotechnology-involved titanium surface to this end once the adhesion and survival characteristics were ameliorated by promoting a higher involvement of β1-Integrin (~1.5-fold changes), Focal Adhesion Kinases (FAK; ~1.5-fold changes) and SRC (~2-fold changes) genes. This signaling pathway culminated with the cofilin involvement (~1.5-fold changes), which guaranteed cytoskeleton rearrangement. Furthermore, nHA_DAE triggered signaling that was able to drive the proliferation of endothelial cells once the cyclin-dependent kinase gene was higher in response to it, while the P15 gene was significantly down-regulated with an impact on the statement of angiogenesis. Altogether, our data show that a nanohydroxyapatite-coated titanium surface ameliorates the EC performance in a high-glucose model in vitro, suggesting its potential application in DM patients.

Morphine-induced mechanical hypersensitivity in mice requires δ receptors, β-arrestin2, and c-Src activity.

Morphine diminishes pain, but its long-term use is compromised by tolerance and hyperalgesia. Studies implicate δ receptors, β-arrestin2 and Src kinase in tolerance. We examined whether these proteins are also involved in morphine-induced hypersensitivity (MIH). A common pathway for tolerance and hypersensitivity may provide a single target to guide improved analgesic approaches. We examined mechanical sensitivity using automated von Frey in wild-type (WT) and transgenic male and female C57Bl/6mice before and after hind paw inflammation by complete Freund's adjuvant (CFA). CFA-evoked hypersensitivity ceased on day 7 in WT but persisted for the 15-day testing period in μ-/- . Recovery was delayed until day 13 in δ-/- . We explored the expression of opioid genes in the spinal cord using quantitative RT-PCR. Restoration to basal sensitivity in WT occurred with increased δ expression. By contrast, κ expression was reduced, while μ remained unchanged. Daily morphine reduced hypersensitivity in WT on day 3 compared to controls; however, hypersensitivity recurred on day 9 and beyond. By contrast, WT had no recurrence of hypersensitivity in the absence of daily morphine. We used β-arrestin2-/- , δ-/- and Src inhibition by dasatinib in WT to establish whether these approaches, which diminish tolerance, also attenuate MIH. While none of these approaches affected CFA-evoked inflammation or acute hypersensitivity, all caused sustained morphine anti-hypersensitivity, abolishing MIH. Like morphine tolerance, MIH in this model requires δ receptors, β-arrestin2 and Src activity. Our findings suggest that MIH is caused by a tolerance-induced reduction in endogenous opioid signalling. KEY POINTS: Morphine is effective for treating severe acute pain, but tolerance and hypersensitivity often develop during its use in treating chronic pain. It is unclear whether these detrimental effects share similar mechanisms; if so, it might be possible to develop a single approach to minimise both phenomena. Mice deficient in μ receptors, δ receptors or β-arrestin2 and wild type mice treated with the Src inhibitor dasatinib exhibit negligible morphine tolerance. We show that these same approaches also prevent the development of morphine-induced hypersensitivity during persistent inflammation. This knowledge identifies strategies, such as the use of Src inhibitors, which may mitigate tolerance and morphine induced hyperalgesia.

Apelin Is a Prototype of Novel Drugs for the Treatment of Acute Myocardial Infarction and Adverse Myocardial Remodeling.

In-hospital mortality in patients with ST-segment elevation myocardial infarction (STEMI) is 5-6%. Consequently, it is necessary to develop fundamentally novel drugs capable of reducing mortality in patients with acute myocardial infarction. Apelins could be the prototype for such drugs. Chronic administration of apelins mitigates adverse myocardial remodeling in animals with myocardial infarction or pressure overload. The cardioprotective effect of apelins is accompanied by blockage of the MPT pore, GSK-3β, and the activation of PI3-kinase, Akt, ERK1/2, NO-synthase, superoxide dismutase, glutathione peroxidase, matrix metalloproteinase, the epidermal growth factor receptor, Src kinase, the mitoKATP channel, guanylyl cyclase, phospholipase C, protein kinase C, the Na+/H+ exchanger, and the Na+/Ca2+ exchanger. The cardioprotective effect of apelins is associated with the inhibition of apoptosis and ferroptosis. Apelins stimulate the autophagy of cardiomyocytes. Synthetic apelin analogues are prospective compounds for the development of novel cardioprotective drugs.

An antibody that targets cell-surface glucose-regulated protein-78 inhibits expression of inflammatory cytokines and plasminogen activator inhibitors by macrophages.

Glucose-regulated protein-78 (Grp78) is an endoplasmic reticulum chaperone, which is secreted by cells and associates with cell surfaces, where it functions as a receptor for activated α2 -macroglobulin (α2 M) and tissue-type plasminogen activator (tPA). In macrophages, α2 M and tPA also bind to the transmembrane receptor, LDL receptor-related protein-1 (LRP1), activating a cell-signaling receptor assembly that includes the NMDA receptor (NMDA-R) to suppress innate immunity. Herein, we demonstrate that an antibody targeting Grp78 (N88) inhibits NFκB activation and expression of proinflammatory cytokines in bone marrow-derived macrophages (BMDMs) treated with the toll-like receptor-4 (TLR4) ligand, lipopolysaccharide, or with agonists that activate TLR2, TLR7, or TLR9. Pharmacologic inhibition of the NMDA-R or deletion of the gene encoding LRP1 (Lrp1) in BMDMs neutralizes the activity of N88. The fibrinolysis protease inhibitor, plasminogen activator inhibitor-1 (PAI1), has been implicated in diverse diseases including metabolic syndrome, cardiovascular disease, and type 2 diabetes. Deletion of Lrp1 independently increased expression of PAI1 and PAI2 in BMDMs, as did treatment of wild-type BMDMs with TLR agonists. tPA, α2 M, and N88 inhibited expression of PAI1 and PAI2 in BMDMs treated with TLR-activating agents. Inhibiting Src family kinases blocked the ability of both N88 and tPA to function as anti-inflammatory agents, suggesting that the cell-signaling pathway activated by tPA and N88, downstream of LRP1 and the NMDA-R, may be equivalent. We conclude that targeting cell-surface Grp78 may be effective in suppressing innate immunity by a mechanism that requires LRP1 and the NMDA-R.

Network Pharmacology and Molecular Modeling to Elucidate the Potential Mechanism of Neem Oil against Acne vulgaris.

Acne vulgaris is a common skin disorder with a complicated etiology. Papules, lesions, comedones, blackheads, and other skin lesions are common physical manifestations of Acne vulgaris, but the individual who has it also regularly has psychological repercussions. Natural oils are being utilized more and more to treat skin conditions since they have fewer negative effects and are expected to provide benefits. Using network pharmacology, this study aims to ascertain if neem oil has any anti-acne benefits and, if so, to speculate on probable mechanisms of action for such effects. The neem leaves (Azadirachta indica) were collected, verified, authenticated, and assigned a voucher number. After steam distillation was used to extract the neem oil, the phytochemical components of the oil were examined using gas chromatography-mass spectrometry (GC-MS). The components of the oil were computationally examined for drug-likeness using Lipinski's criteria. The Pharm Mapper service was used to anticipate the targets. Prior to pathway and protein-protein interaction investigations, molecular docking was performed to predict binding affinity. Neem oil was discovered to be a potential target for STAT1, CSK, CRABP2, and SYK genes in the treatment of Acne vulgaris. In conclusion, it was discovered that the neem oil components with PubChem IDs: ID_610088 (2-(1-adamantyl)-N-methylacetamide), ID_600826 (N-benzyl-2-(2-methyl-5-phenyl-3H-1,3,4-thiadiazol-2-yl)acetamide), and ID_16451547 (N-(3-methoxyphenyl)-2-(1-phenyltetrazol-5-yl)sulfanylpropanamide) have strong affinities for these drug targets and may thus be used as therapeutic agents in the treatment of acne.

Activated Src kinases downstream of BCR-ABL and Flt3 induces proteasomal degradation of SHIP1 by phosphorylation of tyrosine 1021

Within the various subtypes of ALL, patients with a BCR-ABL-positive background as well as with a genetic change in the KMT2A gene have by far the worst survival probabilities. Interestingly, both subtypes are characterized by highly activated tyrosine kinases. SHIP1 serves as an important negative regulator of the PI3K/AKT signaling pathway, which is often constitutively activated in ALL. The protein expression of SHIP1 is decreased in most T-ALL and in some subgroups of B-ALL. In this study, we analyzed the expression of SHIP1 protein in detail in the context of groups with aberrant activated tyrosine kinases, namely BCR-ABL (Ph+) and Flt3 (KMT2A translocations). We demonstrate that constitutively activated Src kinases downstream of BCR-ABL and receptor tyrosine kinases reduce the SHIP1 expression in a SHIP1-Y1021 phosphorylated-dependent manner with subsequent ubiquitin marked proteasomal degradation. Inhibition of BCR-ABL (Imatinib), Flt3 (Quizartinib) or Src-Kinase-Family (Saracatinib) leads to significant reconstitution of SHIP1 protein expression. These results further support a functional role of SHIP1 as tumor suppressor protein and could be the basis for the establishment of a targeted therapy form.

The SOCS1 KIR and SH2 domain are both required for suppression of cytokine signaling in vivo

Suppressor Of Cytokine Signaling (SOCS) 1 is a critical negative regulator of cytokine signaling and required to protect against an excessive inflammatory response. Genetic deletion of Socs1 results in unrestrained cytokine signaling and neonatal lethality, characterised by an inflammatory immune infiltrate in multiple organs. Overexpression and structural studies have suggested that the SOCS1 kinase inhibitory region (KIR) and Src homology 2 (SH2) domain are important for interaction with and inhibition of the receptor-associated JAK1, JAK2 and TYK2 tyrosine kinases, which initiate downstream signaling. To investigate the role of the KIR and SH2 domain in SOCS1 function, we independently mutated key conserved residues in each domain and analysed the impact on cytokine signaling, and the in vivo impact on SOCS1 function. Mutation of the SOCS1-KIR or SH2 domain had no impact on the integrity of the SOCS box complex, however, mutation within the phosphotyrosine binding pocket of the SOCS1-SH2 domain specifically disrupted SOCS1 interaction with phosphorylated JAK1. In contrast, mutation of the KIR did not affect the interaction with JAK1, but did prevent SOCS1 inhibition of JAK1 autophosphorylation. In human and mouse cell lines, both mutants impacted the ability of SOCS1 to restrain cytokine signaling, and crucially, Socs1-R105A and Socs1-F59A mice displayed a neonatal lethality and excessive inflammatory phenotype similar to Socs1-null mice. This study defines a critical and non-redundant role for both the KIR and SH2 domain in endogenous SOCS1 function.

Constitutively active Lyn kinase causes a cutaneous small vessel vasculitis and liver fibrosis syndrome

Neutrophilic inflammation is a hallmark of many monogenic autoinflammatory diseases; pathomechanisms that regulate extravasation of damaging immune cells into surrounding tissues are poorly understood. Here we identified three unrelated boys with perinatal-onset of neutrophilic cutaneous small vessel vasculitis and systemic inflammation. Two patients developed liver fibrosis in their first year of life. Next-generation sequencing identified two de novo truncating variants in the Src-family tyrosine kinase, LYN, p.Y508*, p.Q507* and a de novo missense variant, p.Y508F, that result in constitutive activation of Lyn kinase. Functional studies revealed increased expression of ICAM-1 on induced patient-derived endothelial cells (iECs) and of β2-integrins on patient neutrophils that increase neutrophil adhesion and vascular transendothelial migration (TEM). Treatment with TNF inhibition improved systemic inflammation; and liver fibrosis resolved on treatment with the Src kinase inhibitor dasatinib. Our findings reveal a critical role for Lyn kinase in modulating inflammatory signals, regulating microvascular permeability and neutrophil recruitment, and in promoting hepatic fibrosis.