ABSTRACT
The eIF6 proteins are distributed extensively in eukaryotes and play diverse and essential roles. The bona fide eIF6 protein in Arabidopsis, At-eIF6;1, is essential for embryogenesis. However, the role of eIF6 proteins in rice growth and development remains elusive and requires further investigation. Here, we characterized the functions of OseIF6.1, which is homologous to At-eIF6;1. OseIF6.1 encodes an eukaryotic translation initiation factor with a conserved eIF6 domain. The knockdown of OseIF6.1 resulted in a decrease in grain length and pollen sterility, whereas the overexpression of OseIF6.1 displayed opposite phenotypes. Further studies revealed that OseIF6.1 regulates grain shape by influencing cell expansion and proliferation. In addition, OseIF6.1 interacts with OsNMD3, which is a nuclear export adaptor for the 60S ribosomal subunit. The knockdown of OsNMD3 in plants exhibited reduced fertility and seed setting. Therefore, our findings have significantly enriched the current understanding of the role of OseIF6.1 in rice growth and development.
ABSTRACT
The pivotal role of lysosomal function in preserving neuronal homeostasis is recognized, with its dysfunction being implicated in neurodegenerative processes, notably in Parkinson's disease (PD). Yet, the molecular underpinnings of lysosome-related genes (LRGs) in the context of PD remain partially elucidated. We collected RNA-seq data from the brain substantia nigra of 30 PD patients and 20 normal subjects from the GEO database. We obtained molecular classification clusters from the screened lysosomal expression patterns. The lysosome-related diagnostic model of Parkinson's disease was constructed by XGBoost and Random Forest. And we validated the expression patterns of signature LRGs in the diagnostic model by constructing a PD rat model. Finally, the linkage between PD and cancer through signature genes was explored. The expression patterns of the 33 LRGs screened can be divided into two groups of PD samples, enabling exploration of the variance in biological processes and immune elements. Cluster A had a higher disease severity. Subsequently, critical genes were sieved through the application of machine learning methodologies culminating in the identification of two intersecting feature genes (ACP2 and LRP2). A PD risk prediction model was constructed grounded on these signature genes. The model's validity was assessed through nomogram evaluation, which demonstrated robust confidence validity. Then we analyzed the correlation analysis, immune in-filtration, biological function, and rat expression validation of the two genes with common pathogenic genes in Parkinson's disease, indicating that these two genes play an important role in the pathogenesis of PD. We then selected ACP2, which had a significant immune infiltration correlation, as the entry gene for the pan-cancer analysis. The pan-cancer analysis revealed that ACP2 has profound associations with prognostic indicators, immune infiltration, and tumor-related regulatory processes across various neoplasms, suggesting its potential as a therapeutic target in a range of human diseases, including PD and cancers. Our study comprehensively analyzed the molecular grouping of LRGs expression patterns in Parkinson's disease, and the disease progression was more severe in cluster A. And the PD diagnosis model related to LRGs is constructed. Finally, ACP2 is a potential target for the relationship between Parkinson's disease and tumor.
ABSTRACT
Parkinson's disease (PD) is a common neurodegenerative disease that is mainly in middle-aged people and elderly people, and the pathogenesis of PD is complex and diverse. The ubiquitin-proteasome system (UPS) is a master regulator of neural development and the maintenance of brain structure and function. Dysfunction of components and substrates of this UPS has been linked to neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease. Moreover, UPS can regulate α-synuclein misfolding and aggregation, mitophagy, neuroinflammation and oxidative stress to affect the development of PD. In the present study, we review the role of several related E3 ubiquitin ligases and deubiquitinating enzymes (DUBs) on the pathogenesis of PD such as Parkin, CHIP, USP8, etc. On this basis, we summarize the connections and differences of different E3 ubiquitin ligases in the pathogenesis, and elaborate on the regulatory progress of different DUBs on the pathogenesis of PD. Therefore, we can better understand their relationships and provide feasible and valuable therapeutic clues for UPS-related PD treatment research.
Subject(s)
Neurodegenerative Diseases , Parkinson Disease , Humans , Aged , Middle Aged , Parkinson Disease/etiology , Proteasome Endopeptidase Complex , Ubiquitin , Neurodegenerative Diseases/etiology , Mitophagy , Ubiquitin-Protein LigasesABSTRACT
OBJECTIVE: Repair and regeneration of peripheral nerve defect by engineered conduits have greatly advanced in the past decades while still facing great challenges. APPROACH: In this work, we fabricated a new highly oriented poly(L-lactic acid) (PLLA)/soy protein isolate (SPI) nanofibrous conduit (HO-PSNC) for nerve regeneration. MAIN RESULTS: Firstly, we observed that SPI could efficiently modify PLLA for the electrospinning of PLLA/SPI nanofibers with enhanced physical and biological properties. Incorporation of SPI decreased the fiber diameter and ductility of PLLA/SPI nanofibrous films (PSNFs), improved the tensile strength and surface wettability of PSNFs and increased the in vivo degradability of the PSNFs. When the hybrid ratio of SPI was 20 and 40%, PSNFs could efficiently promote neural cell extension and differentiation in vitro. Based on these data, 20% SPI (PSNF-20) was chosen for further investigation. Next, PSNF-20 with different fiber orientations (random/low orientation, medium, and high orientation, respectively) were developed and used for evaluating neural cell behaviors on the materials. Results revealed that the PSNF-20 with highly oriented nanofibers (HO-PSNF-20) or mediumly oriented nanofibers (MO-PSNF-20) showed a better performance in directing cell extension and enhancing neurite outgrowth. Finally, the highly oriented nanofibers conduits (HO-PSNC-20) were used to bridge sciatic nerve defect in rats with highly oriented PLLA and autografts as controls. HO-PSNC-20 exhibited a significant promotion in nerve regeneration and functional reconstruction comparing to highly oriented PLLA as proven by the evaluations of walking track, electrophysiology, toluidine blue nerve staining, transmission electron microscopy, neural factors staining and qPCR, and gastrocnemius histology. SIGNIFICANCE: In conclusion, nerve conduit fabricated from aligned electrospinning of SPI-modified PLLA nanofibers is promising for peripheral nerve regeneration.
Subject(s)
Nanofibers , Animals , Lactic Acid , Nerve Regeneration , Polyesters , Rats , Sciatic Nerve , Soybean Proteins , Tissue ScaffoldsABSTRACT
Inhaled aztreonam is increasingly used for chronic Pseudomonas aeruginosa suppression in patients with cystic fibrosis (CF), but the potential for that organism to evolve aztreonam resistance remains incompletely explored. Here, we performed genomic analysis of clonally related pre- and posttreatment CF clinical isolate pairs to identify genes that are under positive selection during aztreonam therapy in vivo We identified 16 frequently mutated genes associated with aztreonam resistance, the most prevalent being ftsI and ampC, and 13 of which increased aztreonam resistance when introduced as single gene transposon mutants. Several previously implicated aztreonam resistance genes were found to be under positive selection in clinical isolates even in the absence of inhaled aztreonam exposure, indicating that other selective pressures in the cystic fibrosis airway can promote aztreonam resistance. Given its potential to confer plasmid-mediated resistance, we further characterized mutant ampC alleles and performed artificial evolution of ampC for maximal activity against aztreonam. We found that naturally occurring ampC mutants conferred variably increased resistance to aztreonam (2- to 64-fold) and other ß-lactam agents but that its maximal evolutionary capacity for hydrolyzing aztreonam was considerably higher (512- to 1,024-fold increases) and was achieved while maintaining or increasing resistance to other drugs. These studies implicate novel chromosomal aztreonam resistance determinants while highlighting that different mutations are favored during selection in vivo and in vitro, show that ampC has a high maximal potential to hydrolyze aztreonam, and provide an approach to disambiguate mutations promoting specific resistance phenotypes from those more generally increasing bacterial fitness in vivo.
Subject(s)
Bacterial Proteins/genetics , Cystic Fibrosis/drug therapy , Peptidoglycan Glycosyltransferase/genetics , Pseudomonas Infections/drug therapy , Pseudomonas aeruginosa/genetics , beta-Lactam Resistance/genetics , beta-Lactamases/genetics , Administration, Inhalation , Anti-Bacterial Agents/metabolism , Anti-Bacterial Agents/therapeutic use , Aztreonam/metabolism , Aztreonam/therapeutic use , Cystic Fibrosis/microbiology , Cystic Fibrosis/pathology , DNA Transposable Elements , Gene Expression , Humans , Mutation , Pseudomonas Infections/microbiology , Pseudomonas Infections/pathology , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/enzymology , Pseudomonas aeruginosa/isolation & purification , Selection, GeneticABSTRACT
Adaptation of Staphylococcus aureus to host microenvironments during chronic infection involves spontaneous mutations, yet changes underlying adaptive phenotypes remain incompletely explored. Here, we employed artificial selection and whole-genome sequencing to better characterize spontaneous chromosomal mutations that alter two pathogenicity phenotypes relevant to chronic infection in S. aureus: intracellular invasiveness and intracellular cytotoxicity. We identified 23 genes whose alteration coincided with enhanced virulence, 11 that were previously known and 12 (52%) that had no previously described role in S. aureus pathogenicity. Using precision genome editing, transposon mutants, and gene complementation, we empirically assessed the contributions of individual genes to the two virulence phenotypes. We functionally validated 14 of 21 genes tested as measurably influencing invasion and/or cytotoxicity, including 8 newly implicated by this study. We identified inactivating mutations (murA, ndhC, and a hypothetical membrane protein) and gain-of-function mutations (aroE Thr182Ile, yhcF Thr74Ile, and Asp486Glu in a hypothetical peptidase) in previously unrecognized S. aureus virulence genes that enhance pathogenesis when introduced into a clean genetic background, as well as a novel activating mutation in the known virulence regulator gene saeS (Ala106Thr). Investigation of potentially epistatic interactions identified a tufA mutation (Ala271Val) that enhances virulence only in the context of purine operon repressor gene (purR) inactivation. This project reveals a functionally diverse range of genes affected by gain- or loss-of-function mutations that contribute to S. aureus adaptive virulence phenotypes. More generally, the work establishes artificial selection as a means to determine the genetic mechanisms underlying complex bacterial phenotypes relevant to adaptation during infection.
Subject(s)
Bacterial Proteins/genetics , Mutation , Staphylococcal Infections/microbiology , Staphylococcus aureus/genetics , Staphylococcus aureus/pathogenicity , Bacterial Proteins/metabolism , Chronic Disease , Humans , Staphylococcus aureus/metabolism , Virulence , Virulence Factors/genetics , Virulence Factors/metabolism , Whole Genome SequencingABSTRACT
Staphylococcus aureus is an important human pathogen, but studies of the organism have suffered from the lack of a robust tool set for its genetic and genomic manipulation. Here we report the development of a system for the facile and high-throughput genomic engineering of S. aureus using single-stranded DNA (ssDNA) oligonucleotide recombineering coupled with clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9-mediated counterselection. We identify recombinase EF2132, derived from Enterococcus faecalis, as being capable of integrating single-stranded DNA oligonucleotides into the S. aureus genome. We found that EF2132 can readily mediate recombineering across multiple characterized strains (3 of 3 tested) and primary clinical isolates (6 of 6 tested), typically yielding thousands of recombinants per transformation. Surprisingly, we also found that some S. aureus strains are naturally recombinogenic at measurable frequencies when oligonucleotides are introduced by electroporation, even without exogenous recombinase expression. We construct a temperature-sensitive, two-vector system which enables conditional recombineering and CRISPR/Cas9-mediated counterselection in S. aureus without permanently introducing exogenous genetic material or unintended genetic lesions. We demonstrate the ability of this system to efficiently and precisely engineer point mutations and large single-gene deletions in the S. aureus genome and to yield highly enriched populations of engineered recombinants even in the absence of an externally selectable phenotype. By virtue of utilizing inexpensive, commercially synthesized synthetic DNA oligonucleotides as substrates for recombineering and counterselection, this system provides a scalable, versatile, precise, inexpensive, and generally useful tool for producing isogenic strains in S. aureus which will enable the high-throughput functional assessment of genome variation and gene function across multiple strain backgrounds.IMPORTANCE Engineering genetic changes in bacteria is critical to understanding the function of particular genes or mutations but is currently a laborious and technically challenging process to perform for the important human pathogen Staphylococcus aureus In an effort to develop methods which are rapid, easy, scalable, versatile, and inexpensive, here we describe a system for incorporating synthetic, mutagenic DNA molecules into the S. aureus genome and for eliminating cells that lack the engineered mutation. This method allows efficient, precise, and high-throughput genetic engineering of S. aureus strains and will facilitate studies seeking to address a variety of issues about the function of particular genes and specific mutations.
Subject(s)
Gene Editing/methods , Recombination, Genetic , Staphylococcus aureus/genetics , CRISPR-Associated Protein 9/metabolism , Clustered Regularly Interspaced Short Palindromic Repeats , Humans , Recombinases , Staphylococcal Infections/microbiology , Staphylococcus aureus/isolation & purificationABSTRACT
An increasing number of reports have revealed that long non-coding RNAs are important players in tumorigenesis. Here we showed that long non-coding RNA LINC00461 is highly expressed in glioma tissues compared to non-neoplastic brain tissues. The knockdown of LINC00461 suppressed cyclinD1/A/E expression which led to G0/G1 cell cycle arrest and inhibited cell proliferation in glioma cells. LINC00461 suppression also inhibited glioma cell migration and invasion. The function of LINC00461 in glioma cells is partially mediated by MAPK/ERK and PI3K/AKT signaling pathways as down-regulation of LINC00461 expression suppressed ERK1/2 and AKT activities. Moreover, LINC00461 knockdown decreased expression levels of microRNA miR-9 and flanking genes MEF2C and TMEM161B. Taken together, our results demonstrate that LINC00461 is important for glioma progression affecting cell proliferation, migration and invasion via MAPK/ERK, PI3K/AKT, and possibly other signaling pathways.
ABSTRACT
Glioblastomas are regarded as the most common malignant brain tumours with great morphological and genetical heterogeneity. They comprise 12% to 15% of all intracranial tumours, with its peak observed in the 8th decade of life. The five-year survival is only 5%. Primary glioblastomas are more common in elders while secondary glioblastomas mostly involve younger people. Based upon gene expression profile, researchers have classified glioblastomas into several subtypes. Genetic mutations provide an advanced standard platform essential for diagnosis, therapeutic remedies and prognosis of glioblastomas. Common mutations observed in glioblastomas are loss of heterozygosity at 10q followed by epidermal growth factor receptor amplification (34%) and others. Vascular occlusion model and tumour stem cell model can explain the possible mechanism in glioblastomas pathogenesis. This review highlights glioblastomas' classifications, genetic mutations, pathogenesis and prognosis of different sub-types.
Subject(s)
Brain Neoplasms/classification , Glioblastoma/classification , Brain Neoplasms/genetics , Brain Neoplasms/pathology , Chromosomes, Human, Pair 10/genetics , DNA Methylation , DNA Modification Methylases/genetics , DNA Repair Enzymes/genetics , Genes, erbB-1/genetics , Glioblastoma/genetics , Glioblastoma/pathology , Humans , Isocitrate Dehydrogenase/genetics , Loss of Heterozygosity , Mutation , PTEN Phosphohydrolase/genetics , Promoter Regions, Genetic , Transcriptome , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Proteins/geneticsABSTRACT
The loss of neurotrophic factor support has been shown to contribute to the development of the central nervous system. Glial cell linederived neurotrophic factor (GDNF), a potent neurotrophic factor, is closely associated with apoptosis and exerts neuroprotective effects on numerous populations of cells. However, the underlying mechanisms of these protective effects remain unknown. In the present study, a significant increase in Bax levels and DNA fragmentation was observed in the hippocampus obtained from the brains of diabetic rats 60 days after diabetes had been induced. The apoptotic changes were correlated with the loss of GDNF/Akt signaling. GDNF administration was found to reverse the diabetesinduced Bax and DNA fragmentation changes. This was associated with an improvement in the level of pAkt/Akt. In addition, combination of GDNF with a specific inhibitor of the phosphoinositide 3kinase (PI3K)/Akt pathway, Wortmannin, significantly abrogated the effects of GDNF on the levels of pAkt/Akt, Bax and DNA fragmentation. However, a p38 mitogenactivated proten kinase (MAPK) inhibitor, SB203580, had no effect on the expression of pAkt/Akt, Bax or DNA fragmentation. These results demonstrate the pivotal role of GDNF as well as the PI3K/Akt pathway, but not the MAPK pathway, in the prevention of diabetesinduced neuronal apoptosis in the hippocampus.
Subject(s)
Apoptosis/drug effects , Brain Diseases/pathology , Diabetes Mellitus, Experimental/pathology , Glial Cell Line-Derived Neurotrophic Factor/pharmacology , Hippocampus/pathology , Proto-Oncogene Proteins c-akt/metabolism , Up-Regulation/drug effects , Animals , Brain Diseases/complications , DNA Fragmentation/drug effects , Diabetes Mellitus, Experimental/complications , Enzyme Activation/drug effects , Humans , MAP Kinase Signaling System/drug effects , Male , Phosphorylation/drug effects , Protein Kinase Inhibitors/pharmacology , Rats, Sprague-Dawley , Streptozocin , bcl-2-Associated X Protein/metabolismABSTRACT
There are few studies on the membrane protein Ankfy1. We have found Ankfy1 is specifically expressed in neural stem/precursor cells during early development in mice (murine). To further explore Ankfy1 function in neural development, we developed a gene knockout mouse with a mixed Balb/C and C57/BL6 genetic background. Using immunofluorescence and in situ hybridization, neural defects were absent in mixed genetic Ankfy1 null mice during development and in adults up to 2 months old. However, Ankfy1 gene knockout mice with a pure genetic background were found to be lethal in the C57/BL6 inbred mice embryos, even after seven generations of backcrossing. Polymerase chain reaction confirmed homozygotes were unattainable as early as embryonic day 11.5. We conclude that Ankfy1 protein is dispensable in neural stem/precursor cells, but could be critical for early embryonic murine development, depending on the genetic background.
ABSTRACT
Quercetin is a hydrophobic agent that demonstrates potential anticancer activity. The aim of the present study was to observe the effects of quercetin on the proliferation and apoptosis of the ovarian cancer cell line SKOV-3, and to provide a foundation for the treatment of ovarian cancer using this agent. Ovarian cancer SKOV-3 cells were treated with quercetin at different doses. The inhibitory effect of quercetin on proliferation was detected using the MTT assay and the inhibition rate was calculated. Cell apoptosis was determined using Hoechst staining, and western blot analysis was used to analyze changes in the expression levels of survivin protein. The effects of quercetin on the cell cycle and apoptosis of the SKOV-3 cell line were analyzed using flow cytometry. Quercetin inhibited the proliferation of SKOV-3 cells in a time- and dose-dependent manner. Furthermore, Hoechst staining showed that quercetin induced SKOV-3 cell apoptosis. The protein expression levels of survivin were reduced as the concentration of quercetin increased. Flow cytometric analysis showed that quercetin caused ovarian cancer SKOV-3 cell cycle arrest in the G0/G1 phase and a significant decrease in the percentage of cells at the G2/M phase; furthermore, the apoptosis rate was observed to increase following quercetin treatment. The results in combination indicated that Quercetin could inhibit the proliferation of ovarian cancer SKOV-3 cells, inhibit cell cycle progression from G0/G1 to G2/M and induce cell apoptosis in vitro.
ABSTRACT
The present paper is aimedto investigate the effect of basic fibroblast growth factor (bFGF) on proliferation, migration and differentiation of endogenous neural stem cell in rat cerebral cortex with global brain ischemia-reperfusion. A global brain ischemia-reperfusion model was established. Immunohistochemistry was used to observe the pathological changes and the expression of BrdU and Nestin in cerebral cortex. RT-PCR was used to measure the NSE mRNA in brain tissue. The results of measurements indicated that in sham operation group, there was no positive cell in cerebral cortex, and the content of NSE mRNA did not change. In the operation group, the expression of BrdU and Nestin increased significantly at the end of the 3rd day, and peaked on the 7th day. NSE mRNA expression did not significantly increase. In bFGF group, compared with sham operation group and model group, the number of BrdU-positive and Nestin-positive cells increased significantly at each time point (P<0. 05), and peaked at the end of the 11th day, and the content of NSE mRNA increased significantly (P<0. 05). This research demonstrated that the proliferation of endogenous neural stem cells in situ could be induced by global cerebral ischemia and reperfu- sion, and could be promoted and extended by bFGF. In additiion, bFGF might promote endogenous neural stem cells differentiated into neurons.
Subject(s)
Brain Ischemia/pathology , Fibroblast Growth Factor 2/pharmacology , Neural Stem Cells/drug effects , Animals , Cell Differentiation , Cell Movement , Cell Proliferation , Cerebral Cortex/cytology , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , Nestin/metabolism , Rats , Reperfusion InjuryABSTRACT
The aim of the present study was to explore the effect of esophageal cancer-related gene 2 (ECRG2) protein in combination with cisplatin (DDP) on the proliferation and apoptosis of esophageal cancer cells. A 3-(4, 5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay was used to examine the effects of ECRG2 alone and ECRG2 in combination with DDP on the proliferation of EC9706 esophageal cancer cells. Hoechst 33258 staining was performed to analyze the effects of ECRG2 alone and ECRG2 in combination with DDP on apoptosis in the EC9706 cells. The expression levels of Bcl-2-associated X protein (Bax) mRNA and protein were determined by reverse transcription polymerase chain reaction (RT-PCR) and western blot analysis, respectively. The results from the MTT assay revealed that ECRG2 inhibited the proliferation of EC9706 cells and that ECRG2 in combination with DDP had a greater inhibitory effect on cell proliferation. The antiproliferative effects were time- and concentration-dependent, within a certain range of concentrations. The Hoechst 33258 staining results demonstrated that the number of apoptotic cells following treatment with ECRG2 in combination with DDP for 24 h was higher than that following treatment with ECRG2 alone for the same duration. Western blot analysis and RT-PCR results revealed that the expression levels of Bax mRNA and protein were upregulated in cells treated with ECRG2 in combination with DDP compared with those in cells treated with ECRG2 alone. Thus, ECRG2 in combination with DDP had an enhanced inhibitory effect on EC9706 cell proliferation compared with that of ECRG2 alone, and an increased inductive effect on EC9706 cell apoptosis, possibly due to the upregulation of the expression of Bax.
ABSTRACT
To study the effect of the proliferation and apoptosis of Survivin-T34A mutant on breast cancer MCF-7 cell, we adopted the method of cell culture in vitro to observe the proliferation and apoptosis of the cell. In the experiment, MCF-7 cells were randomly divided into three groups and transfected with normal saline, PORF-9-null and Survivin-T34A, respectively. Breast cancer nude mouse models were established to study anti-tumor effect of Survivin-T34A in vivo. The activity of the cells in the Survivin-T34A-transfected group was lower than that in PORF-9-null group. The increase of cell apoptosis was observed under electron microscopy, meanwhile the apoptotic rate was obviously higher than that in PORF-9-null control by flow cytometry. Tumor inhibition effects of the mouse which received the injection of Survivin-T34A intratumoral injection were apparent, and the inhibition ratio was as high as 47.1%. In conclusion, Survivin-T34A mutant has anti-tumor effect through efficiently inhibiting the growth of breast cancer MCF-7 cell and actively promoting apoptosis of cancer cells.
Subject(s)
Apoptosis , Breast Neoplasms/drug therapy , Inhibitor of Apoptosis Proteins/pharmacology , Animals , Breast Neoplasms/pathology , Humans , Inhibitor of Apoptosis Proteins/genetics , Injections, Intralesional , Mice , Mice, Nude , Neoplasm Transplantation , Survivin , TransfectionABSTRACT
Icotinib is an epidermal growth factor receptor tyrosine kinase inhibitor, which has been revealed to inhibit proliferation in tumor cells. However, the effect of icotinib on cancer cell metastasis remains to be explained. This study examines the effect of icotinib on the migration and invasion of squamous cells of tongue carcinoma (Tca8113 cells) in vitro. The results of the Boyden chamber invasion assay demonstrated that icotinib reduced cell invasion, suppressed the protein levels of matrix metalloproteinases (MMPs), MMP-2 and MMP-9, and increased the expression of tissue inhibitor of metalloproteinase-1. In addition, icotinib was found to significantly decrease the protein levels of nuclear factor κB (NF-κB) p65, which suggested that icotinib inhibits NF-κB activity. Furthermore, treatment with the NF-κB inhibitor, pyrrolidine dithiocarbamate, suppressed cell invasion and MMP-2 expression. These results suggested that icotinib inhibits the invasion of Tca8113 cells by downregulating MMP via the inactivation of the NF-κB signaling pathways.
ABSTRACT
Icotinib, a selective EGFR tyrosine kinase inhibitor (EGFR-TKI), has been shown to exhibit anti-tumor activity against several tumor cell lines. However, the exact molecular mechanism of icotinib's anti-tumor effect remains unknown. This study aims to examine the zytotoxic effect of icotinib on Tca8113 cells and its potential molecular mechanism. Icotinib significantly resulted in dose-dependent cell death as determined by MTT assay, accompanied by increased levels of Bax and DNA fragmentation. Icotinib could also induce Reactive Oxygen Species (ROS) generation. Further studies confirmed that scavenging of reactive oxygen species by N-acetyl-L-cysteine (NAC), and pharmacological inhibition of MAPK reversed icotinib-induced apoptosis in Tca8113 cells. Our data provide evidence that icotinib induces apoptosis, possibly via ROS-mediated MAPK pathway in Tca8113 cells.
Subject(s)
Apoptosis/drug effects , Crown Ethers/pharmacology , Quinazolines/pharmacology , Reactive Oxygen Species/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism , Cell Death/drug effects , Cell Line, Tumor , Enzyme Activation/drug effects , Humans , Oxidative Stress/drug effectsABSTRACT
AIM: To investigate the mechanisms of induction of apoptosis of esophageal cancer cells by esophageal cancer-related gene 2 (ECRG2) in combination with cisplatin (DDP). METHODS: Hoechest staining was performed to analyze the effects of single ECRG2 and ECRG2 in combination with DDP on apoptosis of EC9706 cells. The expression levels of p53 and bcl-2 mRNA and protein were determined by RT-PCR and Western blotting, respectively. RESULTS: The number of apoptotic cells after the treatment with ECRG2 in combination with DDP for 24 hours was more than that after the treatment with single ECRG2. RT-PCR and Western blotting showed that the expression levels of bcl-2 mRNA and protein were both down-regulated, while p53 mRNA and protein were both up-regulated in the cells treated with ECRG2 in combination with DDP compared with those given ECRG2 alone. CONCLUSION: ECRG2 in combination with DDP can enhance the apoptosis of EC9706 cells, possibly by down-regulating bcl-2 expression and up-regulating p53.