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Neuropharmacology Mar 2018Alzheimer's disease remains without a disease-modifying therapy that improves symptoms after therapy withdrawal. Because no investigational agents have demonstrated...
Alzheimer's disease remains without a disease-modifying therapy that improves symptoms after therapy withdrawal. Because no investigational agents have demonstrated disease-modifying effects clinically, we tested whether the Fyn inhibitor, saracatinib, provides persistent improvement in a transgenic model. Aged APPswe/PS1ΔE9 mice were treated with saracatinib or memantine for 4 weeks and spatial memory improved to control levels. After drug washout, there was sustained rescue of both memory function and synapse density by saracatinib, but a loss of benefit from memantine. These data demonstrate a disease-modifying persistent benefit for saracatinib in a preclinincal Alzheimer's model, and distinguish its action from that of memantine.
Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzodioxoles; Maze Learning; Memantine; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microglia; Nootropic Agents; Proto-Oncogene Proteins c-fyn; Quinazolines; Recognition, Psychology; Spatial Learning; Spatial Memory; Spatial Navigation; Synapses
PubMed: 29191754
DOI: 10.1016/j.neuropharm.2017.11.042 -
Molecular Pain 2016Bone metastases occur frequently in advanced breast, lung, and prostate cancer, with approximately 70% of patients affected. Pain is a major symptom of bone metastases,...
BACKGROUND
Bone metastases occur frequently in advanced breast, lung, and prostate cancer, with approximately 70% of patients affected. Pain is a major symptom of bone metastases, and current treatments may be inadequate or have unacceptable side effects. The mechanisms that drive cancer-induced bone pain are not fully understood; however, it is known that there is sensitization of both peripheral bone afferents and central spinal circuits. It is well established that the N-methyl-D-aspartate receptor plays a major role in the pathophysiology of pain hypersensitivity. Inhibition of the non-receptor tyrosine kinase Src controls N-methyl-D-aspartate receptor activity and inhibiting Src reduces the hypersensitivity associated with neuropathic and inflammatory pains. As Src is also implicated in osteoclastic bone resorption, we have investigated if inhibiting Src ameliorates cancer-induced bone pain. We have tested this hypothesis using an orally bioavailable Src inhibitor (saracatinib) in a rat model of cancer-induced bone pain.
RESULTS
Intra-tibial injection of rat mammary cancer cells (Mammary rat metastasis tumor cells -1), but not vehicle, in rats produced hindpaw hypersensitivity to thermal and mechanical stimuli that was maximal after six days and persisted for at least 13 days postinjection. Daily oral gavage with saracatinib (20 mg/kg) beginning seven days after intra-tibial injection reversed the thermal hyperalgesia but not the mechanical allodynia. The analgesic mechanisms of saracatinib appear to be due to an effect on the nervous system as immunoblotting of L2-5 spinal segments showed that mammary rat metastasis tumor cells-1 injection induced phosphorylation of the GluN1 subunit of the N-methyl-D-aspartate receptor, indicative of receptor activation, and this was reduced by saracatinib. Additionally, histology showed no anti-tumor effect of saracatinib at any dose and no significant effect on bone preservation.
CONCLUSIONS
This is the first demonstration that Src plays a role in the development of cancer-induced bone pain and that Src inhibition represents a possible new analgesic strategy for patients with bone metastases.
Topics: Animals; Behavior, Animal; Benzodioxoles; Bone Neoplasms; Bone Remodeling; Bone Resorption; Cancer Pain; Disease Models, Animal; Hyperalgesia; Male; Neurons; Phosphorylation; Protein Kinase Inhibitors; Quinazolines; Rats, Sprague-Dawley; Receptors, N-Methyl-D-Aspartate; Spinal Cord; src-Family Kinases
PubMed: 27094550
DOI: 10.1177/1744806916643725 -
RNA Biology Mar 2021Epithelial-to-mesenchymal transition (EMT) is a hallmark of aggressive, mesenchymal-like high-grade serous ovarian carcinoma (HGSOC). The SRC kinase is a key driver of...
Epithelial-to-mesenchymal transition (EMT) is a hallmark of aggressive, mesenchymal-like high-grade serous ovarian carcinoma (HGSOC). The SRC kinase is a key driver of cancer-associated EMT promoting adherens junction (AJ) disassembly by phosphorylation-driven internalization and degradation of AJ proteins. Here, we show that the IGF2 mRNA-binding protein 1 (IGF2BP1) is up-regulated in mesenchymal-like HGSOC and promotes SRC activation by a previously unknown protein-ligand-induced, but RNA-independent mechanism. IGF2BP1-driven invasive growth of ovarian cancer cells essentially relies on the SRC-dependent disassembly of AJs. Concomitantly, IGF2BP1 enhances ERK2 expression in an RNA-binding dependent manner. Together this reveals a post-transcriptional mechanism of interconnected stimulation of SRC/ERK signalling in ovarian cancer cells. The IGF2BP1-SRC/ERK2 axis is targetable by the SRC-inhibitor saracatinib and MEK-inhibitor selumetinib. However, due to IGF2BP1-directed stimulation, only combinatorial treatment effectively overcomes the IGF2BP1-promoted invasive growth in 3D culture conditions as well as intraperitoneal mouse models. In conclusion, we reveal an unexpected role of IGF2BP1 in enhancing SRC/MAPK-driven invasive growth of ovarian cancer cells. This provides a rationale for the therapeutic benefit of combinatorial SRC/MEK inhibition in mesenchymal-like HGSOC.
Topics: Adherens Junctions; Animals; Biomarkers, Tumor; Cell Line, Tumor; Disease Models, Animal; Epithelial-Mesenchymal Transition; Female; Gene Expression Regulation, Neoplastic; Humans; Mice; Mitogen-Activated Protein Kinases; Ovarian Neoplasms; Protein Binding; Protein Interaction Domains and Motifs; Protein Kinase Inhibitors; RNA-Binding Proteins; Signal Transduction; Xenograft Model Antitumor Assays; src Homology Domains; src-Family Kinases
PubMed: 32876513
DOI: 10.1080/15476286.2020.1812894 -
Molecular Cancer Therapeutics Sep 2021AZD0530, a potent small-molecule inhibitor of the Src kinase family, is an anticancer drug used in the treatment of various cancers. In the case of glioblastoma (GBM),...
AZD0530, a potent small-molecule inhibitor of the Src kinase family, is an anticancer drug used in the treatment of various cancers. In the case of glioblastoma (GBM), where resistance to radiotherapy frequently occurs, Src kinase is known as one of the molecules responsible for imparting radioresistance to GBM. Thus, we evaluated the effect of AZD0530 on the radiosensitivity of human GBM cells and human glioblastoma stem-like cells (GSCs). We show that Src activity of GBM and GSC is increased by radiation and inhibited by AZD0530, and using clonogenic assays, AZD0530 enhances the radiosensitivity of GBM and GSCs. Also, AZD0530 induced a prolongation of radiation-induced γH2AX without specific cell cycle and mitotic index changes, suggesting that AZD0530-induced radiosensitization in GBM cells and GSCs results from the inhibition of DNA repair. In addition, AZD0530 was shown to inhibit the radiation-induced EGFR/PI3K/AKT pathway, which is known to promote and regulate radioresistance and survival of GBM cells by radiation. Finally, mice bearing orthotopic xenografts initiated from GBM cells were then used to evaluate the response to AZD0530 and radiation. The combination of AZD0530 and radiation showed the longest median survival compared with any single modality. Thus, these results show that AZD0530 enhances the radiosensitivity of GBM cells and GSCs and suggest the possibility of AZD0530 as a clinical radiosensitizer for treatment of GBM.
Topics: Animals; Antineoplastic Agents; Apoptosis; Benzodioxoles; Cell Cycle; Cell Proliferation; Female; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; Mice; Mice, Nude; Neoplastic Stem Cells; Quinazolines; Radiation Tolerance; Radiation-Sensitizing Agents; Tumor Cells, Cultured; Xenograft Model Antitumor Assays
PubMed: 34158343
DOI: 10.1158/1535-7163.MCT-20-0883 -
Frontiers in Molecular Neuroscience 2023Neurodegeneration and neuroinflammation are key processes of epileptogenesis in temporal lobe epilepsy (TLE). A considerable number (∼30%) of patients with epilepsy...
Neurodegeneration and neuroinflammation are key processes of epileptogenesis in temporal lobe epilepsy (TLE). A considerable number (∼30%) of patients with epilepsy are resistant to currently available antiseizure drugs and thus there is a need to develop adjunct therapies to modify disease progression. A vast majority of interventional strategies to treat TLE have utilized males which limits the translational nature of the studies. In this study, we investigated the effects of repeated low-dose kainic acid (KA) injection on the initial (SE) and the effects of Src kinase inhibitor, saracatinib (SAR/AZD0530; 20 mg/kg, oral, daily for 7 days), in a mixed-sex cohort of adult Sprague Dawley rats during early epileptogenesis. There were no sex differences in response to KA-induced SE, and neither did the stage of estrus influence SE severity. KA-induced SE caused significant astrogliosis and microgliosis across the hippocampus, piriform cortex, and amygdala. SAR treatment resulted in a significant reduction of microgliosis across brain regions. Microglial morphometrics such as branch length and the endpoints strongly correlated with CD68 expression in the vehicle-treated group but not in the SAR-treated group, indicating mitigation by SAR. KA-induced SE caused significant neuronal loss, including parvalbumin-positive inhibitory neurons, in both vehicle (VEH) and SAR-treated groups. SAR treatment significantly mitigated FJB-positive neuronal counts as compared to the VEH group. There was an increase in C3-positive reactive astrocytes in the VEH-treated group, and SAR treatment significantly reduced the increase in the piriform cortex. C3-positive astrogliosis significantly correlated with CD68 expression in the amygdala (AMY) of VEH-treated rats, and SAR treatment mitigated this relationship. There was a significant increase of pSrc(Y419)-positive microglia in both KA-treated groups with a statistically insignificant reduction by SAR. KA-induced SE caused the development of classical glial scars in the piriform cortex (PIR) in both KA-treated groups, while SAR treatment led to a 42.17% reduction in the size of glial scars. We did not observe sex differences in any of the parameters in this study. SAR, at the dose tested in the rat kainate model for a week in this study mitigated some of the markers of epileptogenesis in both sexes.
PubMed: 38025259
DOI: 10.3389/fnmol.2023.1294514 -
Journal of Gastrointestinal Oncology Dec 2022This paper aims to explore the effects of plasminogen activator, urokinase (PLAU) expression on the migration, invasion, and proliferation of colorectal cancer (CRC)...
BACKGROUND
This paper aims to explore the effects of plasminogen activator, urokinase (PLAU) expression on the migration, invasion, and proliferation of colorectal cancer (CRC) cells and to preliminarily analyze its possible mechanism, thereby laying a foundation for the research on potential biological targets of CRC.
METHODS
CRC-related mRNA was screened in Gene Expression Omnibus (GEO) database (https://www.ncbi.nlm.nih.gov/gds/). Differentially expressed genes (DEGs) were obtained for functional enrichment analysis. The enriched pathway and key involved functional gene were screened for further and analysis CRC cells were transfected with PLAU-NC (negative control), PLAU-mimic, and PLAU-inhibitor for 48 h and divided into the above groups for later studies. The migration, invasion, and proliferation capacities of CRC cells were detected using wound healing, Transwell, and colony formation assays, respectively. The Src inhibitor saracatinib (AZD0530) was added to the PLAU-NC and PLAU-mimic groups, and the expression levels of Src/extracellular signal-regulated kinase (ERK) pathway-, migration-, invasion-, and proliferation-related proteins were detected by Western blotting.
RESULTS
The results showed that after upregulation of PLAU, the number of CRC cells (SW480) that migrated to the center of the wound significantly increased, the number of cells that migrated and invaded through the basement membrane increased in the PLAU-mimic group, and the number of colonies also increased. These results suggest that increasing PLAU expression promotes the migration, invasion, and proliferation of CRC cells. At the same time, the molecular mechanism of PLAU in CRC cells was investigated by downregulating the protein expression of Src combined with the results of the bioinformatics analysis. Western blotting revealed that the protein expressions of phosphorylated Src (p-Src) and phosphorylated ERK (p-ERK) in SW480 and SW620 cells increased significantly in the PLAU-mimic group compared with the PLAU-NC group, while the results were the opposite in the PLAU-inhibitor group. After being treated with saracatinib, we observed significantly decreased protein levels of p-ERK, matrix metallopeptidase 2 (MMP-2), MMP-3, MMP-9, Cyclin D1, and Cyclin A2 in the SW480 cells.
CONCLUSIONS
In conclusion, PLAU affects the migration, invasion, and proliferation of CRC cells by activating the Src/ERK pathway.
PubMed: 36636041
DOI: 10.21037/jgo-22-1215 -
Cancer Science Jun 2018Tyrosine kinase Src is overexpressed and activated in various tumors, including breast cancer, and is supposed to promote cancer formation and development. Src...
Tyrosine kinase Src is overexpressed and activated in various tumors, including breast cancer, and is supposed to promote cancer formation and development. Src inhibitors have been developed recently and have shown efficacy in breast cancer as a single agent or in combination with anti-HER2 antibodies or chemotherapy. Unfortunately, the potency of Src inhibitor is limited by the development of drug resistance. In our study, we established an Src inhibitor saracatinib-resistant breast cancer cell line (SKBR-3/SI) for the first time and by evaluating mRNA expression profile, we found that plasminogen activator inhibitor-1 (PAI-1) was upregulated in saracatinib-resistant cells compared to the parent cells. Further study demonstrated that PAI-1 might induce saracatinib resistance in breast cancer cells by increasing the secretion of chemokine (C-C motif) ligand 5 (CCL5). Functional assays showed that PAI-1 and CCL5 overexpression promoted cell proliferation and migration in breast cancer cells, while inhibition of PAI-1 and CCL5 decreased cell proliferation and migration in saracatinib-resistant cells. We also showed that targeting PAI-1 or CCL5 could reverse saracatinib resistance, which deserves more attention in clinical settings.
Topics: Animals; Benzodioxoles; Breast Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; Chemokine CCL5; Drug Resistance, Neoplasm; Enzyme Inhibitors; Female; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Mice, Inbred BALB C; Mice, Nude; Plasminogen Activator Inhibitor 1; Quinazolines; Receptor, ErbB-2; Xenograft Model Antitumor Assays; src-Family Kinases
PubMed: 29601121
DOI: 10.1111/cas.13593 -
Oncotarget Jan 2018SRC tyrosine kinase is frequently overexpressed and activated in late-stage, poor prognosis ovarian tumours, and preclinical studies have supported the use of targeted...
SRC tyrosine kinase is frequently overexpressed and activated in late-stage, poor prognosis ovarian tumours, and preclinical studies have supported the use of targeted SRC inhibitors in the treatment of this disease. The SAPPROC trial investigated the addition of the SRC inhibitor saracatinib (AZD0530) to weekly paclitaxel for the treatment of platinum resistant ovarian cancer; however, this drug combination did not provide any benefit to progression free survival (PFS) of women with platinum resistant disease. In this study we aimed to identify mechanisms of resistance to SRC inhibitors in ovarian cancer cells. Using two complementary strategies; a targeted tumour suppressor gene siRNA screen, and a phospho-receptor tyrosine kinase array, we demonstrate that activation of MAPK signalling, via a reduction in NF1 (neurofibromin) expression or overexpression of HER2 and the insulin receptor, can drive resistance to AZD0530. Knockdown of NF1 in two ovarian cancer cell lines resulted in resistance to AZD0530, and was accompanied with activated MEK and ERK signalling. We also show that silencing of HER2 and the insulin receptor can partially resensitize AZD0530 resistant cells, which was associated with decreased phosphorylation of MEK and ERK. Furthermore, we demonstrate a synergistic effect of combining SRC and MEK inhibitors in both AZD0530 sensitive and resistant cells, and that MEK inhibition is sufficient to completely resensitize AZD0530 resistant cells. This work provides a preclinical rationale for the combination of SRC and MEK inhibitors in the treatment of ovarian cancer, and also highlights the need for biomarker driven patient selection for clinical trials.
PubMed: 29435137
DOI: 10.18632/oncotarget.23524 -
Clinical Cancer Research : An Official... Mar 2021Alterations in DNA damage repair (DDR) pathway genes occur in 20%-25% of men with metastatic castration-resistant prostate cancer (mCRPC). Although PARP inhibitors...
PURPOSE
Alterations in DNA damage repair (DDR) pathway genes occur in 20%-25% of men with metastatic castration-resistant prostate cancer (mCRPC). Although PARP inhibitors (PARPis) have been shown to benefit men with mCRPC harboring DDR defects due to mutations in and ATM, additional treatments are necessary because the effects are not durable.
EXPERIMENTAL DESIGN
We performed transcriptomic analysis of publicly available mCRPC cases, comparing null with wild-type. We generated -null prostate cancer cells using CRISPR/Cas9 and treated these cells with PARPis and SRC inhibitors. We also assessed the antiproliferative effects of combination treatment in 3D prostate cancer organoids.
RESULTS
We observed significant enrichment of the SRC signaling pathway in -altered mCRPC. -null prostate cancer cell lines had increased SRC phosphorylation and higher sensitivity to SRC inhibitors (e.g., dasatinib, bosutinib, and saracatinib) relative to wild-type cells. Combination treatment with PARPis and SRC inhibitors was antiproliferative and had a synergistic effect in -null prostate cancer cells, mCRPC organoids, and Trp53/Rb1-null prostate cancer cells. Inhibition of SRC signaling by dasatinib augmented DNA damage in -null prostate cancer cells. Moreover, knockdown increased PARPi sensitivity in -null prostate cancer cells.
CONCLUSIONS
This work suggests that SRC activation may be a potential mechanism of PARPi resistance and that treatment with SRC inhibitors may overcome this resistance. Our preclinical study demonstrates that combining PARPis and SRC inhibitors may be a promising therapeutic strategy for patients with -null mCRPC.
Topics: Animals; Antineoplastic Agents; Apoptosis; BRCA2 Protein; Cell Proliferation; Drug Synergism; Drug Therapy, Combination; Gene Expression Regulation, Neoplastic; Humans; Male; Mice; Mice, Nude; Poly(ADP-ribose) Polymerase Inhibitors; Prognosis; Prostatic Neoplasms, Castration-Resistant; Survival Rate; Synthetic Lethal Mutations; Tumor Cells, Cultured; Xenograft Model Antitumor Assays; src-Family Kinases
PubMed: 33334906
DOI: 10.1158/1078-0432.CCR-20-2483 -
International Journal of Molecular... Jun 2024Glioblastoma (GBM) is the most common primary malignant brain tumor in adults, with few effective treatments. EGFR alterations, including expression of the truncated...
Glioblastoma (GBM) is the most common primary malignant brain tumor in adults, with few effective treatments. EGFR alterations, including expression of the truncated variant EGFRvIII, are among the most frequent genomic changes in these tumors. EGFRvIII is known to preferentially signal through STAT5 for oncogenic activation in GBM, yet targeting EGFRvIII has yielded limited clinical success to date. In this study, we employed patient-derived xenograft (PDX) models expressing EGFRvIII to determine the key points of therapeutic vulnerability within the EGFRvIII-STAT5 signaling axis in GBM. Our findings reveal that exogenous expression of paralogs STAT5A and STAT5B augments cell proliferation and that inhibition of STAT5 phosphorylation in vivo improves overall survival in combination with temozolomide (TMZ). STAT5 phosphorylation is independent of JAK1 and JAK2 signaling, instead requiring Src family kinase (SFK) activity. Saracatinib, an SFK inhibitor, attenuates phosphorylation of STAT5 and preferentially sensitizes EGFRvIII+ GBM cells to undergo apoptotic cell death relative to wild-type EGFR. Constitutively active STAT5A or STAT5B mitigates saracatinib sensitivity in EGFRvIII+ cells. In vivo, saracatinib treatment decreased survival in mice bearing EGFR WT tumors compared to the control, yet in EGFRvIII+ tumors, treatment with saracatinib in combination with TMZ preferentially improves survival.
Topics: STAT5 Transcription Factor; Glioblastoma; Humans; Animals; Quinazolines; Benzodioxoles; Mice; ErbB Receptors; Phosphorylation; Cell Line, Tumor; Temozolomide; Cell Proliferation; Xenograft Model Antitumor Assays; Signal Transduction; Brain Neoplasms; Apoptosis; src-Family Kinases; Tumor Suppressor Proteins
PubMed: 38892466
DOI: 10.3390/ijms25116279