This service exclusively searches for literature that cites resources. Please be aware that the total number of searchable documents is limited to those containing RRIDs and does not include all open-access literature.
The epidermal growth factor receptor (EGFR) plays a critical role in the control of cellular proliferation, differentiation, and survival. Abnormalities in EGF-EGFR signaling, such as mutations that render the EGFR hyperactive or cause overexpression of the wild-type receptor, have been found in a broad range of cancers, including carcinomas of the lung, breast, and colon. EGFR inhibitors such as gefitinib have proven successful in the treatment of certain cancers, particularly non-small cell lung cancers (NSCLCs) harboring activating mutations within the EGFR gene, but the molecular mechanisms leading to tumor regression remain unknown. Therefore, we wished to delineate these mechanisms.
Reactive oxygen species (ROS) modulate the growth of neural stem/precursor cells (NS/PCs) and participate in hippocampus-associated learning and memory. However, the origin of these regulatory ROS in NS/PCs is not fully understood. In the present study, we found that Nox4, a ROS-producing NADPH oxidase family protein, is expressed in primary cultured NS/PCs and in those of the adult mouse brain. Nox inhibitors VAS 2870 and GKT137831 or Nox4 deletion attenuated bFGF-induced proliferation of cultured NS/PCs, while lentivirus-mediated Nox4 overexpression increased the production of H2O2, the phosphorylation of Akt, and the proliferation of cultured NS/PCs. Nox4 did not significantly affect the potential of cultured NS/PCs to differentiate into neurons or astrocytes. The histological and functional development of the hippocampus appeared normal in Nox4-/- mice. Although pathological and functional damages in the hippocampus induced by the neurotoxin trimethyltin were not significantly different between wild-type and Nox4-/- mice, the post-injury reactive proliferation of NS/PCs and neurogenesis in the subgranular zone (SGZ) of the dentate gyrus were significantly impaired in Nox4-/- animals. Restoration from the trimethyltin-induced impairment in recognition and spatial working memory was also significantly attenuated in Nox4-/- mice. Collectively, our findings suggest that Nox4 participates in NS/PC proliferation and neurogenesis in the hippocampus following injury, thereby helping to restore memory function.
The timing of anti-coagulation therapy initiation after acute cardioembolic stroke remains controversial. We investigated the effects of post-stroke administration of a factor Xa inhibitor in mice, focusing on tissue repair and functional restoration outcomes. We initiated administration of rivaroxaban, a Xa inhibitor, immediately after permanent distal middle cerebral artery occlusion (pMCAO) in CB-17 mice harboring few leptomeningeal anastomoses at baseline. Rivaroxaban initiated immediately after pMCAO hindered the recovery of blood flow in ischemic areas by inhibiting leptomeningeal anastomosis development, and led to impaired restoration of neurologic functions with less extensive peri-infarct astrogliosis. Within infarct areas, angiogenesis and fibrotic responses were attenuated in rivaroxaban-fed mice. Furthermore, inflammatory responses, including the accumulation of neutrophils and monocytes/macrophages, local secretion of pro-inflammatory cytokines, and breakdown of the blood-brain barrier, were enhanced in infarct areas in mice treated immediately with rivaroxaban following pMCAO. The detrimental effects were not found when rivaroxaban was initiated after transient MCAO or on day 7 after pMCAO. Collectively, early post-stroke initiation of a factor Xa inhibitor may suppress leptomeningeal anastomosis development and blood flow recovery in ischemic areas, thereby resulting in attenuated tissue repair and functional restoration unless occluded large arteries are successfully recanalized.
Chromosome instability (CIN), the hallmarks of cancer, reflects ongoing chromosomal changes caused by chromosome segregation errors and results in whole chromosomal or segmental aneuploidy. In multiple myeloma (MM), CIN contributes to the acquisition of tumor heterogeneity, and thereby, to disease progression, drug resistance, and eventual treatment failure; however, the underlying mechanism of CIN in MM remains unclear. Faithful chromosomal segregation is tightly regulated by a series of mitotic checkpoint proteins, such as budding uninhibited by benzimidazoles 1 (BUB1). In this study, we found that BUB1 was overexpressed in patient-derived myeloma cells, and BUB1 expression was significantly higher in patients in an advanced stage compared to those in an early stage. This suggested the involvement of aberrant BUB1 overexpression in disease progression. In human myeloma-derived cell lines (HMCLs), BUB1 knockdown reduced the frequency of chromosome segregation errors in mitotic cells. In line with this, partial knockdown of BUB1 showed reduced variations in chromosome number compared to parent cells in HMCLs. Finally, BUB1 overexpression was found to promote the clonogenic potency of HMCLs. Collectively, these results suggested that enhanced BUB1 expression caused an increase in mitotic segregation errors and the resultant emergence of subclones with altered chromosome numbers and, thus, was involved in CIN in MM.
RSK2 is a serine/threonine kinase downstream signaling mediator in the RAS/ERK signaling pathway and may be a therapeutic target in mantle cell lymphoma (MCL), an almost incurable disease subtype of non-Hodgkin lymphoma. In this study, serine-227 (RSK2Ser227 ) in the N-terminal kinase domain (NTKD) of RSK2 was found to be ubiquitously active in five MCL-derived cell lines and in tumor tissues derived from five MCL patients. BI-D1870, an inhibitor specific to RSK2-NTKD, caused RSK2Ser227 dephosphorylation, and thereby, induced dose-dependent growth inhibition via G2 /M cell cycle blockade and apoptosis in four of the five cell lines, while one cell line showed only modest sensitivity. In addition, RSK2 gene knockdown caused growth inhibition in the four BI-D1870-sensitive cell lines. Comparative gene expression profiling of the MCL-derived cell lines showed that inhibition of RSK2Ser227 by BI-D1870 caused downregulation of oncogenes, such as c-MYC and MYB; anti-apoptosis genes, such as BCL2 and BCL2L1; genes for B cell development, including IKZF1, IKZF3, and PAX5; and genes constituting the B cell receptor signaling pathway, such as CD19, CD79B, and BLNK. These findings show that targeting of RSK2Ser227 enables concomitant blockade of pathways that are critically important in B cell tumorigenesis. In addition, we found favorable combinatory growth inhibitory effects of BI-D1870 with inhibitors of BTK (ibrutinib), AKT (ipatasertib), and BCL2 (venetoclax) in cell characteristic-dependent manners. These results provide a rationale for RSK2Ser227 in the NTKD as a potential therapeutic target in MCL and for future development of a novel bioavailable RSK2 NTKD-specific inhibitor.
Osteoclasts (OCs) are specialized cells for the resorption of bone matrix that have also been recently reported to be involved in the mobilization of hematopoietic progenitor cells. When Ba/F3 cells expressing wild-type bcr-abl were co-cultured with osteoblasts (OBs), OCs, and bone slices, their proliferation was significantly suppressed, and the Ki-67 negative population, which is believed to be in G(0) phase, was increased. The results of our in vitro experiments suggest that OCs could be involved in the maintenance of dormant leukemic cells in the bone marrow (BM) microenvironment through the release of soluble factors, one of which could be TGF-beta.
Objective It has been postulated that the normal counterpart of angioimmunoblastic T-cell lymphoma (AITL) is the follicular helper T-cell (TFH). Recent immunological studies have identified several transcription factors responsible for T-cell differentiation. The master regulators associated with T-cell, helper T-cell (Th), and TFH differentiation are reportedly BCL11B, Th-POK, and BCL6, respectively. We explored the postulated normal counterpart of AITL with respect to the expression of the master regulators of T-cell differentiation. Methods We performed an immunohistochemical analysis in 15 AITL patients to determine the expression of the master regulators and several surface markers associated with T-cell differentiation. Results BCL11B was detected in 10 patients (67%), and the surface marker of T-cells (CD3) was detected in all patients. Only 2 patients (13%) expressed the marker of naïve T-cells (CD45RA), but all patients expressed the marker of effector T-cells (CD45RO). Nine patients expressed Th-POK (60%), and 7 (47%) expressed a set of surface antigens of Th (CD4-positive and CD8-negative). In addition, BCL6 and the surface markers of TFH (CXCL13, PD-1, and SAP) were detected in 11 (73%), 8 (53%), 14 (93%), and all patients, respectively. Th-POK-positive/BCL6-negative patients showed a significantly shorter overall survival (OS) than the other patients (median OS: 33.0 months vs. 74.0 months, p=0.020; log-rank test). Conclusion Many of the AITL patients analyzed in this study expressed the master regulators of T-cell differentiation. The clarification of the diagnostic significance and pathophysiology based on the expression of these master regulators in AITL is expected in the future.
We investigated clinical and genetic characteristics of high-risk follicular lymphoma (FL), that lacked evidence of large cell transformation at diagnosis, in the rituximab era. First, we retrospectively analysed the clinical features of 100 patients with non-transformed FL that were consecutively treated with rituximab-containing therapies in a discovery cohort. The presence of either peripheral blood and/or bone involvement was associated with short progression-free survival. This was confirmed in a validation cohort of 66 FL patients. Then, whole exome sequencing was performed on randomly selected 5 high- and 9 standard-risk FL tumours. The most common mutational signature was a CG > TG substitution-enriched signature associated with spontaneous deamination of 5-methylcytosine at CpG, but mutations in WA and WRC(Y) motifs (so-called activation-induced cytidine deaminase (AID) motifs) were also enriched throughout the whole exome. We found clustered mutations in target sequences of AID in the IG and BCL2 loci. Importantly, high-risk FLs harboured more somatic mutations (mean 190 vs. 138, P = 0.04), including mutations in WA (33 vs. 22, P = 0.038), WRC (34 vs. 22, P = 0.016) and WRCY motifs (17 vs. 11, P = 0.004). These results suggest that genomic instability that allows for emergence of distinct mutations through AID activity underlies development of the high-risk FL phenotype.
Regulated upon Activation, Normal T-cell Expressed, and Secreted (RANTES) is a well-known pro-inflammatory chemokine and its role in ischemic stroke remains controversial. We examined the significance of RANTES in ischemic stroke and aimed to elucidate the direct effect of RANTES on neurons. Plasma concentrations of major C-C chemokines, including RANTES, and neurotrophic factors were examined in 171 ischemic stroke patients and age- and gender- matched healthy subjects. Plasma concentrations of RANTES at day 0 after onset were significantly elevated in stroke patients, compared with controls, and were highly correlated with those of BDNF, EGF, and VEGF. In a mouse middle cerebral artery occlusion model (MCAO), plasma RANTES was significantly elevated and the expression of RANTES was markedly upregulated in neurons particularly in peri-infarct areas. The expression of CCR3 and CCR5, receptors for RANTES, was also induced in neurons, while another receptor, CCR1, was observed in vascular cells, in peri-infarct areas after MCAO. We examined the effects of RANTES on differentiated PC12 cells, a model of neuronal cells. Treatment with RANTES induced the activation of Akt and Erk1/2, and attenuated the cleavage of caspase-3 in the cells. RANTES increased the expression of BDNF, EGF, and VEGF in the cells. Moreover, RANTES maintained the number of cells under serum free conditions. The RANTES-mediated upregulation of neurotrophic factors and cell survival were significantly attenuated by the inhibition of Akt or Erk1/2. Taken together, RANTES is an interesting chemokine that is produced from neurons after ischemic stroke and has the potential to protect neurons directly or indirectly through the production of neurotrophic factors in peri-infarct areas.
Multiple myeloma (MM) is characterized by remarkable cytogenetic/molecular heterogeneity among patients and intraclonal diversity even in a single patient. We previously demonstrated that PDPK1, the master kinase of series of AGC kinases, is universally active in MM, and plays pivotal roles in cell proliferation and cell survival of myeloma cells regardless of the profiles of cytogenetic and genetic abnormalities. This study investigated the therapeutic efficacy and mechanism of action of dual blockade of two major PDPK1 substrates, RSK2 and AKT, in MM. The combinatory treatment of BI-D1870, an inhibitor for N-terminal kinase domain (NTKD) of RSK2, and ipatasertib, an inhibitor for AKT, showed the additive to synergistic anti-tumor effect on human MM-derived cell lines (HMCLs) with active RSK2-NTKD and AKT, by enhancing apoptotic induction with BIM and BID activation. Moreover, the dual blockade of RSK2 and AKT exerted robust molecular effects on critical gene sets associated with myeloma pathophysiologies, such as those with MYC, mTOR, STK33, ribosomal biogenesis, or cell-extrinsic stimuli of soluble factors, in HMCLs. These results provide the biological and molecular rationales for the dual-targeting strategy for RSK2 and AKT, which may overcome the therapeutic difficulty due to cytogenetic/molecular heterogeneity in MM.
Novel therapeutic drugs have dramatically improved the overall survival of patients with multiple myeloma. We sought to identify the characteristics of patients likely to exhibit a durable response to one such drug, elotuzumab, by analyzing a real-world database in Japan. We analyzed 179 patients who underwent 201 elotuzumab treatments. The median time to next treatment (TTNT) with the 95% confidence interval was 6.29 months (5.18-9.20) in this cohort. Univariate analysis showed that patients with any of the following had longer TTNT: no high risk cytogenic abnormalities, more white blood cells, more lymphocytes, non-deviated κ/λ ratio, lower β2 microglobulin levels (B2MG), fewer prior drug regimens, no prior daratumumab use and better response after elotuzumab treatment. A multivariate analysis showed that TTNT was longer in patients with more lymphocytes (≥ 1400/μL), non-deviated κ/λ ratio (0.1-10), lower B2MG (< 5.5 mg/L) and no prior daratumumab use. We proposed a simple scoring system to predict the durability of the elotuzumab treatment effect by classifying the patients into three categories based on their lymphocyte counts (0 points for ≥ 1400/μL and 1 point for < 1400/μL) and κ/λ ratio (0 points for 0.1-10 and 1 point for < 0.1 or ≥ 10) or B2MG (0 points for < 5.5 mg/L and 1 point for ≥ 5.5 mg/L). The patients with a score of 0 showed significantly longer TTNT (p < 0.001) and better survival (p < 0.001) compared to those with a score of 1 or 2. Prospective cohort studies of elotuzumab treatment may be needed to validate the usefulness of our new scoring system.
B-cell lymphomas (BCLs) are the most common disease entity among hematological malignancies and have various genetically and molecularly distinct subtypes. In this study, we revealed that the blockade of phosphoinositide-dependent kinase-1 (PDPK1), the master kinase of AGC kinases, induces a growth inhibition via cell cycle arrest and the induction of apoptosis in all eight BCL-derived cell lines examined, including those from activated B-cell-like diffuse large B-cell lymphoma (DLBCL), double expressor DLBCL, Burkitt lymphoma, and follicular lymphoma. We also demonstrated that, in these cell lines, RSK2, AKT, and S6K, but not PLK1, SGK, or PKC, are the major downstream therapeutic target molecules of PDPK1 and that RSK2 plays a central role and AKT and S6K play subsidiary functional roles as the downstream effectors of PDPK1 in cell survival and proliferation. Following these results, we confirmed the antilymphoma efficacy of TAS0612, a triple inhibitor for total RSK, including RSK2, AKT, and S6K, not only in these cell lines, regardless of disease subtypes, but also in all 25 patient-derived B lymphoma cells of various disease subtypes. At the molecular level, TAS0612 caused significant downregulation of MYC and mTOR target genes while inducing the tumor suppressor TP53INP1 protein in these cell lines. These results prove that the simultaneous blockade of RSK2, AKT, and S6K, which are the pivotal downstream substrates of PDPK1, is a novel therapeutic target for the various disease subtypes of BCLs and line up TAS0612 as an attractive candidate agent for BCLs for future clinical development.
Welcome to the FDI Lab - SciCrunch.org Resources search. From here you can search through a compilation of resources used by FDI Lab - SciCrunch.org and see how data is organized within our community.
You are currently on the Community Resources tab looking through categories and sources that FDI Lab - SciCrunch.org has compiled. You can navigate through those categories from here or change to a different tab to execute your search through. Each tab gives a different perspective on data.
If you have an account on FDI Lab - SciCrunch.org then you can log in from here to get additional features in FDI Lab - SciCrunch.org such as Collections, Saved Searches, and managing Resources.
Here is the search term that is being executed, you can type in anything you want to search for. Some tips to help searching:
You can save any searches you perform for quick access to later from here.
We recognized your search term and included synonyms and inferred terms along side your term to help get the data you are looking for.
If you are logged into FDI Lab - SciCrunch.org you can add data records to your collections to create custom spreadsheets across multiple sources of data.
Here are the facets that you can filter your papers by.
From here we'll present any options for the literature, such as exporting your current results.
If you have any further questions please check out our FAQs Page to ask questions and see our tutorials. Click this button to view this tutorial again.
Year:
Count: