High expression of Ras-specific guanine nucleotide-releasing factor 2 (RasGRF2) in lung adenocarcinoma is associated with tumor invasion and poor prognosis.
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ABSTRACT:
SUBMITTER: Nakagawa T
PROVIDER: S-EPMC8251786 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:RasGRP4 (Ras guanine nucleotide-releasing protein-4) is an intracellular, calcium-regulated guanine nucleotide exchange factor and diacylglycerol/phorbol ester receptor expressed in mast cells (MCs) and their progenitors. To study the function of this signaling protein in inflammatory disorders, a homologous recombination approach was used to create a RasGRP4-null C57BL/6 mouse line. The resulting transgenic animals had normal numbers of MCs in their tissues that histochemically and morphologically resembled those in WT C57BL/6 mice. MCs could also be generated from RasGRP4-null mice by culturing their bone marrow cells in IL-3-enriched conditioned medium. Despite these data, the levels of the transcripts that encode the proinflammatory cytokines IL-1? and TNF-? were reduced in phorbol 12-myristate 13-acetate-treated MCs developed from RasGRP4-null mice. Although inflammation was not diminished in a Dermatophagoides farinae-dependent model of allergic airway disease, dextran sodium sulfate-induced colitis was significantly reduced in RasGRP4-null mice relative to similarly treated WT mice. Furthermore, experimental arthritis could not be induced in RasGRP4-null mice that had received K/BxN mouse serum. The latter findings raise the possibility that the pharmacologic inactivation of this intracellular signaling protein might be an effective treatment for arthritis or inflammatory bowel disease.
| S-EPMC3370188 | biostudies-literature
Project description:Background: The long non-coding RNA Linc00152 stimulates tumor progression in cancer. However, its clinical significance and biological functions in lung adenocarcinoma remains unknown. We evaluate the expression of Linc00152 in lung adenocarcinoma and its possible correlation with clinicopathologic features and patient survival to reveal its biological effects in cancer progression and prognosis. Methods: Total RNA extraction was performed on 110 pairs of lung adenocarcinoma and adjacent normal tissue samples, and then RT-qPCR was conducted. Chi-square test analysis was used to calculate the correlation between pathological parameters and the Linc00152 mRNA levels. Kaplan-Meier and Cox proportional hazards analyses were used to analyze the overall survival (OS) and disease-free survival (DFS) rates. We also detected the potential functional effects of overexpression and knockdown of Linc00152 in vitro cell proliferation, tumor cell invasion and migration, as well as in vivo nude mouse xenograft and metastasis models. Results: The Linc00152 expression levels were higher in lung adenocarcinoma samples than in the adjacent normal tissues. Linc00152 expression levels tightly correlated with lymph node metastasis station, remote metastasis and TNM staging. The Kaplan-Meier analysis suggested that high Linc00152 expression caused significantly poorer OS and DFS rates, and a multivariate analysis revealed that Linc00152 was an independent risk factor for both DFS and OS. Overexpression of Linc00152 in lung cancer cells stimulated proliferation, tumor cell invasion and migration. Knockdown of Linc00152 inhibited cell growth and cell invasion and migration. Finally, Linc00152 knockdown inhibited lung tumor growth and tumor metastasis in nude mice models. Conclusions: Our study suggests that Linc00152 independently predicts poor prognosis and promotes tumor progression in lung adenocarcinoma. Linc00152 needs to be considered as a potential molecular target in future cancer pharmacology.
| S-EPMC5559966 | biostudies-other
Project description:The Ras-specific nucleotide exchange factor Son of sevenless (Sos) is inactive without Ras bound to a distal allosteric site. In contrast, the catalytic domain of Ras guanine nucleotide releasing factor 1 (RasGRF1) is active intrinsically. By substituting residues from RasGRF1 into Sos, we have generated mutants of Sos with basal activity, partially relieved of their dependence on allosteric activation. We have performed molecular dynamics simulations showing how Ras binding to the allosteric site leads to a bias toward the active conformation of Sos. The trajectories show that Sos fluctuates between active and inactive conformations in the absence of Ras and that the activating mutations favor conformations of Sos that are more permissive to Ras binding at the catalytic site. In contrast, unliganded RasGRF1 fluctuates primarily among active conformations. Our results support the premise that the catalytic domain of Sos has evolved an allosteric activation mechanism that extends beyond the simple process of membrane recruitment.
| S-EPMC2654222 | biostudies-literature
Project description:Background: The role of RASGRF2 has been verified in the development of various cancers. However, its roles in stomach adenocarcinoma (STAD) are still under investigation. Methods: RASGRF2 transcript-level data and the associated clinical information from patients with STAD were extracted from The Cancer Genome Atlas (TCGA). Diagnostic and prognostic values of RASGRF2 were analyzed using receiver-operator characteristics (ROC) analysis, correlation analysis, and survival analysis in conjunction with a prognostic model. In addition, gene expression profiles, differentially-expressed genes for co-varying expression, and a differential expressed genes (DEG) protein-protein interaction network for influential nodes were also analyzed. To identify the molecular role of RASGRF2 in STAD, gene ontology (GO) term, Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathway, and gene set enrichment analysis (GSEA)-mediated functional module enrichment analyses were conducted. The relationship between RASGRF2 and gene signature-based predicted immune cell infiltration patterns were also investigated. To validate the bioinformatic findings, RASGRF2 protein expression was investigated in vitro using western blot and immunohistochemistry. Furthermore, relationships among RASGRF2 protein expression, clinicopathologic characteristics, and patient survival were analyzed. Results: Bioinformatic analysis revealed a significantly higher RASGRF2 transcript level in STAD tissue, which was positively associated with the T stage, histological type, histological grade, and TP53 status. Moreover, the RASGRF2 transcript level indicated poor overall survival in STAD patients (hazard ratio = 1.47, P = 0.023). Multivariate Cox regression analysis showed that primary therapy outcome, age, and RASGRF2 transcript level were independent prognostic factors for survival, and the C-index of a nomogram was 0.695. Additionally, 159 genes were differentially expressed according to RASGRF2 transcript levels; 15 exhibited co-varying expression, and 13 were identified as influential nodes. The DEG-list was significantly enriched for several GO terms, biological pathways, and functional modules, including MAPK, RAS, ERK, and immunoregulatory pathways. RASGRF2 transcript levels were significantly positively correlated with infiltration levels of Tem, Macrophages, pDCs, and NK cells. Validation analysis showed similar results for the RASGRF2 protein expression level in both in vitro analyses. Conclusion: Bioinformatic predictions combined with in vitro validation suggest that RASGRF2 plays diagnostic and prognostic roles and serves as a negative protective molecular factor in STAD patients.
| S-EPMC8558656 | biostudies-literature
Project description:L-dopa-induced dyskinesia (LID) is a common debilitating complication of dopamine replacement therapy in Parkinson's disease. Recent evidence suggests that LID may be linked causally to a hyperactivation of the Ras-ERK signaling cascade in the basal ganglia. We set out to determine whether specific targeting of Ras-guanine nucleotide-releasing factor 1 (Ras-GRF1), a brain-specific activator of the Ras-ERK pathway, may provide a therapy for LID. On the rodent abnormal involuntary movements scale, Ras-GRF1-deficient mice were significantly resistant to the development of dyskinesia during chronic L-dopa treatment. Furthermore, in a nonhuman primate model of LID, lentiviral vectors expressing dominant negative forms of Ras-GRF1 caused a dramatic reversion of dyskinesia severity leaving intact the therapeutic effect of L-dopa. These data reveal the central role of Ras-GRF1 in governing striatal adaptations to dopamine replacement therapy and validate a viable treatment for LID based on intracellular signaling modulation.
| S-EPMC3003069 | biostudies-literature
Project description:Background: Topoisomerase IIA (TOP2A) gene encodes DNA topoisomerase enzyme and has been reported that TOP2A is broadly expressed in many types of cancers. Our study aims to investigate the prognostic effect of TOP2A on lung adenocarcinoma (LUAD) and the potential molecular mechanism of TOP2A to tumorigenesis. Methods: Bioinformatical analysis, real-time PCR and Western blot were applied to explore the expression level of TOP2A. Kaplan-Meier survival analysis was used to evaluate the effect of TOP2A on patients' prognosis. Cell proliferation, migration and invasion ability were examined by colony-formation, Cell Counting Kit-8 (CCK8) assay, wound healing assay and transwell invasion assay, respectively. Results: We firstly investigated differentially expressed genes in lung adenocarcinoma and normal tissues of GEO (tumor = 666, normal = 184) and TCGA (tumor = 517, normal = 59) and these data showed that TOP2A is broadly expressed in LUAD and the expression level of TOP2A is associated with poor prognosis, which indicated that TOP2A is an upregulated prognostic related gene in LUAD. Then we identified that the expression level of TOP2A was upregulated in both surgically removed lung cancer tissues and lung cancer cell lines. Knockdown of TOP2A in A549 and GLC82 cells inhibited cell proliferation, migration and invasion. Inhibition of TOP2A reduced the expression levels of CCNB1 and CCNB2, which indicated that TOP2A targeting CCNB1 and CCNB2 promotes GLC82 and A549 cells proliferation and metastasis. Conclusions: Our study revealed an important role of TOP2A in LUAD, and may provide a potential prognostic indicator and target for cancer therapy.
| S-EPMC7066024 | biostudies-literature
Project description:BackgroundThis study was conducted to investigate the clinical significance of claudin-1 (CLDN1) expression in patients with lung adenocarcinoma.MethodsWe examined CLDN1 protein expression by immunohistochemistry in a tissue microarray from 258 patients with lung adenocarcinoma. We investigated messenger ribonucleic acid (mRNA) expression in H358 (formerly bronchioloalveolar carcinoma) and lung adenocarcinoma cell lines (A549) by real-time reverse transcriptase-polymerase chain reaction.ResultsMultivariate analysis showed that prognostic factors for lung adenocarcinoma were histologic type, CLDN1, T stage and N stage. Patients with positive CLDN1 expression had a poorer prognosis than patients with negative CLDN1 expression. CLDN1 expression was correlated with Ras and epidermal growth factor receptor (EGFR) expression. Patients with positive expressions of both CLDN1 and Ras/EGFR had a poorer prognosis than patients with CLDN1 (+) Ras/EGFR(-) or CLDN1 (-) Ras/EGFR(+) and patients with negative expressions of both CLDN1 and Ras/EGFR. CLDN1 mRNA expression was lower in the H358 compared with the lung adenocarcinoma cell line (A549).ConclusionThe combination of CLDN1 and Ras/EGFR is a valuable independent prognostic predictor for lung adenocarcinoma.
| S-EPMC5130200 | biostudies-literature
Project description:Objectives: DNA damage inducible transcript 4 (DDIT4) plays a key role in different cancers, but the role of DDIT4 in lung adenocarcinoma (LUAD) is not completely understood. The aim of this study was to evaluate the utility of DDIT4 as a prognostic biomarker for LUAD. Methods: First, DDIT4 mRNA expression in LUAD cell lines (A549, H1299 and HBE) and tissues (89 cases) was assessed by RT-PCR. Next, DDIT4 protein expression in LUAD tissues and normal tissues was assessed by immunohistochemistry (75 cases). Then, the correlation between DDIT4 expression and overall survival was analyzed using the Kaplan-Meier method. After that, we verified the utility of the DDIT4 gene as a prognostic marker of lung cancer in the TCGA database (1133 cases). Finally, the possible mechanism of the DDIT4 gene as a prognostic marker of LUAD was preliminarily explored. Results: mRNA levels of DDIT4 in HBE cells were significantly lower than in A549 and H1299 cells (P<0.05), and expression of the DDIT4 gene in cancer tissues was significantly higher than in adjacent tissues (P<0.0001). Immunohistochemical staining results showed that high expression of DDIT4 accounted for approximately 68.0% of LUAD tissues. DDIT4 expression was significantly correlated with differentiation (P < 0.05). However, it was not correlated with sex, age, smoking, tumor size, lymph node metastasis, or TNM stage (P>0.05). The survival analysis demonstrated that high DDIT4 expression was correlated with shorter overall survival (P < 0.05). Univariate and multivariate analyses indicated that DDIT4 was an independent predictor of overall survival for LUAD, which was confirmed by data from the TCGA database. Finally, we found that DDIT4 gene expression was significantly increased in the hypoxic environment compared to the normal oxygen environment, indicating that the DDIT4 gene may play an important role in the hypoxic microenvironment of tumor tissue. Conclusion: High expression levels of DDIT4 correlated with poor overall survival in patients with LUAD, and DDIT4 was an independent predictor of overall survival. These findings provide new insight for understanding the development of LUAD.
| S-EPMC8489140 | biostudies-literature
Project description:BackgroundsThe deubiquitinating enzyme OTUB1 participates in multiple cellular processes. However, its expression and functions in gastric adenocarcinoma remains unknown. The aim of this study was to investigate the expression of OTUB1 and its biological role in gastric adenocarcinoma.MethodsWe used immunohistochemistry to analyze OTUB1 expressions levels in 80 paired samples of gastric adenocarcinoma and adjacent normal tissue (ANT) and 30 samples of intraepithelial neoplasia (IN). We also analyzed the correlation between OTUB1 expression and clinicopathological parameters and patient survival status. Moreover, we performed wound-healing, transwell, RT-qPCR and Western blot assays to evaluate the impact of OTUB1 on tumor migration and invasion.ResultsIn gastric adenocarcinomas, staining for OTUB1 was localized in the cytoplasm. The proportion of samples that expressed OTUB1 and the intensity of its expression were much higher in gastric adenocarcinoma tissues (61 out of 80, 76.25%) than that in either IN (10 out of 30, 33.33%, p<0.001) or ANT (7 out of 80, 8.75%, p<0.001) samples. In malignant cases, higher expression OTUB1 levels were significantly associated with deeper tumor invasion depths (p=0.02), advanced lymph node status (p=0.008) and TNM stage (p=0.001), lymph duct invasion (p<0.001) and nerve invasion (p=0.013). Univariate and multivariate Cox regression analyses revealed that OTUB1 was an independent risk factor for disease-specific survival but not disease-free survival. In vitro wound-healing and transwell assays showed that OTUB1 overexpression promoted tumor cell migration and invasion in gastric cancer cells.ConclusionOTUB1 contributes to gastric cancer development by enhancing tumor invasiveness. Targeting OTUB1 should be considered in future molecular therapies.
| S-EPMC4891435 | biostudies-literature
Project description:BackgroundInterleukin 6 (IL6) is both a pleiotropic cytokine and an immune-related gene. Interleukin 6 receptor (IL6R) is the receptor for IL6. It may be closely connected to the development of lung cancer. This research aims to explore the prognostic value of IL6R and prevent overtreatment of patients with lung adenocarcinoma (LUAD).MethodsIn this study, the expression of IL6R in tumor tissues and surrounding tissues was first analyzed by immunohistochemistry in the Affiliated Hospital of Nantong University (NTU) cohort. Secondly, we downloaded information from The Cancer Genome Atlas (TCGA) for the TCGA cohort and used this information to explore the messenger RNA (mRNA) level of IL6R. We then used Kaplan-Meier survival analyses, univariate and multivariate Cox analyses, nomogram models, and decision curve analyses to assess the prognostic value of IL6R. In addition, we also analyzed immune cell infiltration and the signaling pathways related to IL6R through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA).ResultsThrough the data analysis of the NTU cohort and the TCGA cohort, it was found that the expression of IL6R in normal tissues around the tumor was higher than that in tumor tissue, and was positively correlated with the overall survival (OS) of LUAD patients. Additionally, low expression of IL6R was found to be an independent predictor of poor prognosis among the patients in these two research cohorts. Next, using GO, KEGG, and GSEA analyses, we found that partially infiltrated tumor immune cells might be related to earlier staging and better prognosis of patients with LUAD. Finally, the study of the 3-5-year survival rate of LUAD patients through the nomogram showed that the expression of IL6R could improve the accuracy of prediction to prevent the overtreatment of some LUAD patients.ConclusionsIn summary, our study indicated that the low expression of IL6R was associated with poor prognosis among LUAD patients and that low expression of IL6R is a potential independent risk factor that could provide a basis for strengthening postoperative classification management of such patients.
| S-EPMC8339841 | biostudies-literature