Loss of protein homeostasis is a hallmark of cellular senescence, and ribosome pausing plays a crucial role in the collapse of proteostasis. However, our understanding of ribosome pausing in senescent cells remains limited. In this study, we utilized ribosome profiling and G-quadruplex RNA immunoprecipitation sequencing techniques to explore the impact of RNA G-quadruplex (rG4) on the translation efficiency in senescent cells. Our results revealed a reduction in the translation efficiency of rG4-rich genes in senescent cells and demonstrated that rG4 structures within coding sequence can impede translation both in vivo and in vitro. Moreover, we observed a significant increase in the abundance of rG4 structures in senescent cells, and the stabilization of the rG4 structures further exacerbated cellular senescence. Mechanistically, the RNA helicase DHX9 functions as a key regulator of rG4 abundance, and its reduced expression in senescent cells contributing to increased ribosome pausing. Additionally, we also observed an increased abundance of rG4, an imbalance in protein homeostasis, and reduced DHX9 expression in aged mice. In summary, our findings reveal a novel biological role for rG4 and DHX9 in the regulation of translation and proteostasis, which may have implications for delaying cellular senescence and the aging process.
G-Quadruplexes ; Cellular Senescence ; Ribosomes/genetics* ; Humans ; Animals ; Mice ; DEAD-box RNA Helicases/genetics* ; Protein Biosynthesis ; RNA/chemistry* ; Neoplasm Proteins

Objective To investigate effect of let-7a gene over-expression on apoptosis of gastric cancer cell lines SGC-7901.Methods The stable let-7a gene over-expressing SGC-7901 cells, SGC-7901/let-7a cells, were established using shRNA lentiviral vector methods. Real-time RT-PCR analysis was used to evaluate the expression level of let-7a mRNA. Cells apoptosis was assessed by flow cytometry.Results RT-PCR analysis revealed let-7a expression in SGC-7901/let-7a cells was significantly increased. Cellular apoptosis assay showed that over-expression of let-7a could increase apoptosis of SGC-7901 cells (P=0.002).Conclusion Up-regulating let-7a expression promoted apoptosis in SGC-7901 cells.
Apoptosis ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; Humans ; MicroRNAs ; biosynthesis ; genetics ; RNA, Neoplasm ; biosynthesis ; genetics ; Stomach Neoplasms ; genetics ; metabolism ; pathology ; Up-Regulation

MTUS1 (microtubule-associated tumor suppressor 1) has been identified that can function as a tumor suppressor gene in many malignant tumors. However, the function and mechanisms underlying the regulation of MTUS1 are unclear. In the present study, we reported that miR-19a and miR-19b (miR-19a/b) promote proliferation and migration of lung cancer cells by targeting MTUS1. First, MTUS1 was proved to function as a tumor suppressor in lung cancer and was linked to cell proliferation and migration promotion. Second, an inverse correlation between miR-19a/b expression and MTUS1 mRNA/protein expression was noted in human lung cancer tissues. Third, MTUS1 was appraised as a direct target of miR-19a/b by bioinformatics analysis. Fourth, direct MTUS1 regulation by miR-19a/b in lung cancer cells was experimentally affirmed by cell transfection assay and luciferase reporter assay. Finally, miR-19a/b were shown to cooperatively repress MTUS1 expression and synergistically regulate MTUS1 expression to promote lung cancer cell proliferation and migration. In conclusion, our findings have provided the first clues regarding the roles of miR-19a/b, which appear to function as oncomirs in lung cancer by downregulating MTUS1.
A549 Cells ; Cell Movement ; Cell Proliferation ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Lung Neoplasms ; genetics ; metabolism ; pathology ; Male ; MicroRNAs ; genetics ; metabolism ; RNA, Neoplasm ; genetics ; metabolism ; Tumor Suppressor Proteins ; biosynthesis ; genetics

INTRODUCTIONC-X-C chemokine receptor type 7 (CXCR7) has recently been characterised as a novel receptor for the C-X-C motif chemokine 12 (CXCL12)/stromal cell-derived factor 1-alpha. CXCR7 has been thought to play an important role in the pathogenesis of chronic rhinosinusitis, angiogenesis and tumour metastasis. The present study aimed to examine the expression of CXCR7 in tissue samples of laryngeal cancer and maxillary sinus carcinoma to determine its role in the development of otorhinolaryngologic neoplasms.

METHODSSamples of otorhinolaryngologic neoplasms were obtained from 17 patients with either nasal polyps (n = 7), laryngeal cancer (n = 5) or maxillary sinus carcinoma (n = 5), and who underwent surgical resection at West China Hospital of Sichuan University. Total RNA was isolated and CXCR7 mRNA expression was examined and quantified by relative real-time reverse transcription polymerase chain reaction. A one-way analysis of variance was performed using SPSS Statistics version 11.0 (SPSS Inc, Chicago, IL, USA) to compare the CXCR7 mRNA levels among the three groups of patients.

RESULTSAll samples tested positive for CXCR7 mRNA. The quantitative results showed that the CXCR7 mRNA levels were highest in laryngeal cancer and lowest in maxillary sinus carcinoma neoplasms, although there was no significant difference among the three samples.

CONCLUSIONCXCL12 and its receptor CXCR7 may contribute to eosinophilic inflammation in patients with chronic sinusitis and nasal polyps. Our results also suggest that CXCR7 may play a role in the progression, metastasis and angiogenesis of otorhinolaryngologic tumours.

Aged ; Biomarkers, Tumor ; biosynthesis ; genetics ; Carcinoma, Squamous Cell ; genetics ; metabolism ; pathology ; Disease Progression ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Male ; Middle Aged ; Otorhinolaryngologic Neoplasms ; genetics ; metabolism ; pathology ; RNA, Neoplasm ; genetics ; Real-Time Polymerase Chain Reaction ; Receptors, CXCR ; biosynthesis ; genetics

UNLABELLED: Abstract OBJECTIVE: To measure the expression of CK18 and CK19 in the cells from peripheral blood and tumor tissue of the nasopharyngeal carcinoma patients,to test whether CK 18 and CK 19 could be biomarkers of nasopharyngeal carcinoma fordiagnosis. METHOD: The mRNA was extracted from the blood and carcinoma tissue of nasopharyngeal carcinoma and was reversed transcription to cDNA. The 3 pairs primers were designed for RT-PCR and the fold value was calculated to evaluated expression by ΔCT. RESULT: There are no statistical differences between the CK18 and CK19 gene expression and the gender, age and metastasis in tumor tissue of 45 nasopharyngeal carcinoma patients (P>0. 05). There are significant differences among 3 pathological stages and 2 genes expressed increase as the grade malignancy (P<0. 05). The detecting of the 2 genes expression from blood cells shows that CK18 and CK19 had a high positive ratio 64% and 75% respectively. Meanwhile this method showed a same detection characteristic in tumor and blood, the positive.rate of CK18 and CK19 genes in metastasis is higher than non-metastasis. The results showed CK18 has a high specificity and CK19 has a high sensitivity for prognosis and all relapsed cases are associated with the expression of CK18 and CK19. CONCLUSION CK18 and CK19 may be used as biomarkers of nasopharyngeal carcinoma for diagnosis.
Biomarkers, Tumor ; Carcinoma ; DNA, Complementary ; Gene Expression ; Humans ; Keratin-18 ; biosynthesis ; Keratin-19 ; biosynthesis ; Nasopharyngeal Carcinoma ; Nasopharyngeal Neoplasms ; diagnosis ; metabolism ; pathology ; Neoplasm Metastasis ; Prognosis ; RNA, Messenger ; Reverse Transcriptase Polymerase Chain Reaction

This study investigated the effects of miRNA-155 on malignant biological characteristics of NK/T-cell lymphoma cell lines and the possible mechanism. The expression of miRNA-155 was detected in lymphoma cell lines from different sources (SNK-6, YTS, Jurkat and DOHH2) by real-time PCR. Lentiviral vectors (pLL3.7) that could overexpress or downexpress miRNA-155 were constructed. Recombinant lentiviral particles were prepared and purified, and their titers determined. The expression of miRNA-155 in the infected SNK-6 cells and the cell proliferation were detected by PCR and CCK-8, respectively. Flow cytometry was used to determine the apoptosis of infected SNK-6 cells. The target of miRNA155 was predicted from Targetscan website. The effect of miRNA155 on FOXO3a expression was examined by Western blotting. The results showed that among the human NK/T-cell lymphoma cell lines SNK-6, YTS, Jurkat and DOHH2, the expression of miRNA-155 was highest in SNK-6. The infection efficiency of the recombinant lentivirus in SNK-6 was more than 70% at multiplicity of infection (MOI) of 100. The expression of miRNA-155 was significantly increased in SNK-6 cells infected by lentivirus vectors with high expression of miRNA-155 (4 times higher than the control group), and profoundly decreased in those infected with lentiviruses with low expression of miRNA-155. The proliferation of letivirus-infected SNK-6 cells was decreased as the expression of miRNA-155 reduced. The apoptosis rate was increased with the reduction in the expression of miRNA-155. FOXO3a was found to be a possible target of miRNA155, as suggested by Targetscan website. Western blotting showed that the expression of FOXO3a was significantly elevated in SNK-6 cells with miRNA-155 inhibition. It was concluded that reduction in miRNA-155 expression can inhibit the proliferation of SNK-6 lymphoma cells and promote their apoptosis, which may be associated with regulation of FOXO3a gene.
Apoptosis ; genetics ; Forkhead Box Protein O3 ; Forkhead Transcription Factors ; genetics ; metabolism ; Gene Expression Regulation, Neoplastic ; Humans ; Jurkat Cells ; Lymphoma, T-Cell ; genetics ; metabolism ; pathology ; MicroRNAs ; biosynthesis ; genetics ; Natural Killer T-Cells ; metabolism ; pathology ; Neoplasm Proteins ; genetics ; metabolism ; RNA, Neoplasm ; biosynthesis ; genetics ; Transduction, Genetic

OBJECTIVETo investigate trichorhinophalangeal syndrome 1 gene (TRPS-1) expression patterns in different subtypes of breast cancer and its correlations with other genes and survival using microarray data sets.

METHODSThe transcripts of TRPS-1 and its role in survival in breast cancer were analyzed using published microarray data sets#x02014;Netherlands Cancer Institute (NKI) cohort and Wang cohort.

RESULTSTRPS-1 expression was lower in basal-like breast cancer. The mRNA levels of TRPS-1 negatively correlated with Slug (Pearson correlation coefficient=-0.1366, P=0.0189 in NKI data set and Pearson correlation coefficient=-0.1571, P=0.0078 in Wang data set), FOXC1 (Pearson correlation coefficient=-0.1211, P=0.0376 in NKI data set and Pearson correlation coefficient=-0.1709, P=0.0037 in Wang data set), and CXCL1 (Pearson correlation coefficient=-0.1197, P=0.0399 in NKI data set and Pearson correlation coefficient=-0.3436, P<0.0001 in Wang data set), but positively correlated with BRCA1 (Pearson correlation coefficient=0.1728, P=0.0029 in NKI data set and Pearson correlation coefficient=0.1805, P=0.0022 in Wang data set). Low TRPS-1 expression associated with poor overall survival (hazard ratio 1.79, 95% CI of ratio 0.9894 to 3.238, P=0.054) and relapse-free survival (hazard ratio 1.913, 95% CI of ratio 1.159 to 3.156, P<0.05). The low TRPS-1 mRNA levels predicted poor outcome in breast cancer patients by the 70-gene signature.

CONCLUSIONThe strong expression of TRPS-1 may serve as a good prognostic marker in breast cancer.

Adult ; Biomarkers, Tumor ; biosynthesis ; Breast Neoplasms ; metabolism ; mortality ; pathology ; Cell Line, Tumor ; Cohort Studies ; DNA-Binding Proteins ; biosynthesis ; Disease-Free Survival ; Epithelial-Mesenchymal Transition ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Middle Aged ; Neoplasm Proteins ; biosynthesis ; RNA, Messenger ; biosynthesis ; RNA, Neoplasm ; biosynthesis ; Survival Rate ; Transcription Factors ; biosynthesis

OBJECTIVETo explore the effect of down-regulation of astrocyte elevated gene-1 (AEG-1) expression on cell proliferation and cell cycle of gastric carcinoma cells, and its possible molecular mechanism.

METHODSControl siRNA and AEG-1 siRNA were transfected into gastric carcinoma SGC-7901 cells. 48 h after transfection, the cells were divided into 3 groups including untransfected, siRNA control and AEG-1 siRNA transfection groups. Expressions of AEG-1 mRNA and protein in the 3 group cells were detected by real-time quantitative PCR and Western blot. The changes of cell proliferation were examined using CCK-8 kit, and the cell cycle distribution was detected by flow cytometry. Finally, expressions of cell proliferation and cell cycle related proteins were detected by Western blot.

RESULTSReal-time quantitative PCR and Western blot demonstrated that compared with the untransfected and siRNA control groups, expressions of AEG-1 mRNA and protein were significantly down-regulated in the AEG-1 siRNA transfection group (P < 0.05), but there was no significant difference between the untransfected and siRNA control groups (P > 0.05). Furthermore, in vivo experiment confirmed a significant down-regulation of AEG-1 protein in the AEG-1 siRNA transfection group (P < 0.05). In addition, AEG-1 siRNA obviously inhibited the proliferation of SGC-7901 cells at different time points after transfection with AEG-1 siRNA. The percentage of cells in G0/G1 phase in the AEG-1 siRNA transfection group [(61.26 ± 1.25)%] was significantly higher than those in the untransfected group [(46.17 ± 1.91)%] and siRNA control group [(46.46 ± 1.96)%], and there was a significant difference between them (all P < 0.001). Furthermore, the result of Western blotting revealed that down-regulation of AEG-1 expression evoked the down-regulation of cdk2 and cyclin D1 expressions and elevation of p21 expression in vitro and in vivo.

CONCLUSIONSThe inhibition of cell proliferation and cell cycle arrest mediated by down-regulation of AEG-1 expression may be closely associated with the changes of expression of cell cycle related proteins including cdk2, cyclin D1 and p21.

Animals ; Cell Adhesion Molecules ; biosynthesis ; genetics ; Cell Cycle Checkpoints ; Cell Line, Tumor ; Cell Proliferation ; Cyclin D1 ; metabolism ; Cyclin-Dependent Kinase 2 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Down-Regulation ; Female ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; RNA Interference ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Stomach Neoplasms ; metabolism ; pathology ; Transfection

This study was aimed to investigate the expression of GST-CML28 in Escherichia Coli and to prepare its antibody. The constructed recombinant expression vectors CML28-pGEX-3X were transformed into Escherichia Coli BL21 under IPTG induction. The protein was abstracted from the transformers, and purified by a GSTrap FF column. The rabbits were immunized by the purified fusion protein to produce serum with anti-CML28 antibody. The serum was purified by chromatographic column stuffed with glutathione Sephamse 4B to get the antibody. The specific antibody against CML28 was further identified by ELISA, Western blot, immunohistochemistry and quantum dot luminescence. The results indicated that GST-CML28 fusion protein was expressed in Escherichia coli and its specific polyclonal antibody was obtained. It is concluded that the anti-CML28 polyclonal antibodies with high titer and specificity are successfully prepared. These antibodies provide an useful experimental tool to profoundly research the physiological significance and biological function of the CML28 gene.
Animals ; Antibodies ; immunology ; isolation & purification ; metabolism ; Antigens, Neoplasm ; biosynthesis ; immunology ; isolation & purification ; Cells, Cultured ; Escherichia coli ; metabolism ; Exosome Multienzyme Ribonuclease Complex ; biosynthesis ; immunology ; isolation & purification ; Genetic Vectors ; Glutathione Transferase ; biosynthesis ; isolation & purification ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; RNA-Binding Proteins ; biosynthesis ; immunology ; isolation & purification ; Rabbits ; Recombinant Fusion Proteins ; biosynthesis ; immunology ; isolation & purification

MicroRNAs, known as small noncoding MiRNAs, 19 to 24 nt in length, are important gene regulators and recognized as key players in carcinogenesis. The mechanism lies in that the MiRNAs can conjugate with their targeted mRNA and then lead to the targeted mRNA degradation or repress their translation. Bioinformatic analysis indicates that each MiRNA can regulate hundreds of gene targets and could serve functionally as "oncogenes" or "tumor suppressor genes", and therefore regulate multiple cellular processes relevant to carcinogenesis and cancer progression. Up to now, there have been a lot of studies about the MiRNAs which may play an important role in stomach neoplasms. The purpose of this paper is to have a review of the present studies on the MiRNAs related to stomach neoplasms, in order set basis for further study and their clinical application.
Gene Expression Regulation, Neoplastic ; genetics ; Humans ; Neoplasm Metastasis ; genetics ; RNA Interference ; RNA, Small Interfering ; biosynthesis ; genetics ; Stomach Neoplasms ; genetics ; metabolism ; pathology