Ribosomal protein S15A augments human osteosarcoma cell proliferation in vitro

TMED3/RPS15A Axis promotes the development and progression of osteosarcoma

Background

Osteosarcoma is a primary malignant tumor that mainly affects children and young adults. Transmembrane emp24 trafficking protein 3 (TMED3) may be involved in the regulation of malignant cancer behaviors. However, the role of TMED3 in osteosarcoma remains mysterious. In this study, the potential biological function and underlying mechanism of TMED3 in progression of osteosarcoma was elaborated.

Methods

The expression of TMED3 in osteosarcoma was analyzed by immunohistochemical staining. The biological function of TMED3 in osteosarcoma was determined through loss-of-function assays in vitro. The effect of TMED3 downregulation on osteosarcoma was further explored by xenograft tumor model. The molecular mechanism of the regulation of TMED3 on osteosarcoma was determined by gene expression profile analysis.

Results

The expression of TMED3 in osteosarcoma tissues was significantly greater than that in matched adjacent normal tissues. Knockdown of TMED3 inhibited the progression of osteosarcoma by suppressing proliferation, impeding migration and enhancing apoptosis in vitro. We further validated that knockdown of TMED3 inhibited osteosarcoma generation in vivo. Additionally, ribosomal protein S15A (RPS15A) was determined as a potential downstream target for TMED3 involved in the progression of osteosarcoma. Further investigations elucidated that the simultaneous knockdown of RPS15A and TMED3 intensified the inhibitory effects on osteosarcoma cells. Importantly, knockdown of RPS15A alleviated the promotion effects of TMED3 overexpression in osteosarcoma cells.

Conclusions

In summary, these findings emphasized the importance of TMED3/RPS15A axis in promoting tumor progression, which may be a promising candidate for molecular therapy of osteosarcoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02340-w.

Identification of key genes and pathways involved in abdominal aortic aneurysm initiation and progression

OBJECTIVE

The study aimed to assess the gene expression profile of biopsies obtained from the neck of human abdominal aortic aneurysm (AAA) and the main site of AAA dilatation and to investigate the molecular mechanism underlying the development of AAA.

METHODS

The microarray profile of GSE47472 and GSE57691 were obtained from the Gene Expression Omnibus (GEO) database. The GSE47472 was a microarray dataset of tissues from the aortic neck of AAA patients versus normal controls. The GSE57691 was a microarray dataset including the tissues from main site of AAA dilatation versus normal controls. Differentially expressed genes (DEGs) were chosen using the R package and annotated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomics (KEGG). The hub genes were identified in the protein-protein interaction (PPI) network.

RESULTS

342 upregulated DEGs and 949 downregulated DEGs were obtained from GSE47472. The upregulated DEGs were mainly enriched in biological regulation (ontology: BP), the membrane (ontology: CC), and protein binding (ontology: MF), and the downregulated genes were mainly enriched in biological regulation (ontology: BP), the membrane (ontology: CC), and protein blinding (ontology: MF). In the KEGG enrichment analysis, the DEGs mainly involved glycosaminoglycan degradation, vasopressin-regulated water reabsorption, and pyruvate metabolism. The hub genes in GSE47472 mainly include VAMP8, PTPRC, DYNLL1, RPL38, RPS4X, HNRNPA1, PRMT1, TGOLN2, PA2G4, and CUL2. From GSE57691, 248 upregulated DEGs and 1120 downregulated DEGs were selected. The upregulated DEGs of GSE57691 were mainly enriched in biological regulation (ontology: BP), the membrane (ontology: CC), and protein binding (ontology: MF), and the downregulated genes were mainly enriched in metabolic process (ontology: BP), the membrane (ontology: CC), and protein blinding (ontology: MF). In the KEGG enrichment analysis, the DEGs mainly involved the mitochondrial respiratory, respiratory chain complex, and respiratory chain. RPS15A, RPS5, RPL23, RPL27A, RPS24, RPL35A, RPS4X, RPL7, RPS25, and RPL21 were identified as the hub genes.

CONCLUSION

At the early stage of AAA, the current study indicated the importance of glycosaminoglycan degradation and anaerobic metabolism. We also identified several hub genes closely related to AAA (VAMP8, PTPRC, DYNLL1, etc.). At the progression of the AAA, the dysfunctional mitochondria played a critical role in AAA formation and the RPS15A, RPS5, RPL23, etc., were identified as the hub genes.

Herpesvirus-Associated Proliferative Skin Disease in Frogs and Toads: Proposed Pathogenesis

A comparative study was carried out on common and agile frogs (Rana temporaria and R. dalmatina) naturally infected with ranid herpesvirus 3 (RaHV3) and common toads (Bufo bufo) naturally infected with bufonid herpesvirus 1 (BfHV1) to investigate common pathogenetic pathways and molecular mechanisms based on macroscopic, microscopic, and ultrastructural pathology as well as evaluation of gene expression. Careful examination of the tissue changes, supported by in situ hybridization, at different stages of development in 6 frogs and 14 toads revealed that the skin lesions are likely transient, and part of a tissue cycle necessary for viral replication in the infected hosts. Transcriptomic analysis, carried out on 2 naturally infected and 2 naïve common frogs (Rana temporaria) and 2 naturally infected and 2 naïve common toads (Bufo bufo), revealed altered expression of genes involved in signaling and cell remodeling in diseased animals. Finally, virus transcriptomics revealed that both RaHV3 and BfHV1 had relatively high expression of a putative immunomodulating gene predicted to encode a decoy receptor for tumor necrosis factor in the skin of the infected hosts. Thus, the comparable lesions in infected frogs and toads appear to reflect a concerted epidermal and viral cycle, with presumptive involvement of signaling and gene remodeling host and immunomodulatory viral genes.

The thin ret(raction) line: biomedical journal responses to incorrect non-targeting nucleotide sequence reagents in human gene knockdown publications

The capacity of the scientific literature to self-correct is of vital importance, but few studies have compared post-publication journal responses to specific error types. We have compared journal responses to a specific reagent error in 31 human gene knockdown publications, namely a non-targeting or negative control nucleotide sequence that is instead predicted to target a human gene. The 31 papers published by 13 biomedical journals generated 26 published responses (14 retractions, 5 expressions of concern, 7 author corrections which included one resolved expression of concern) as well as 6 stated decisions to take no action. Variations in published responses were noted both between journals and by 4 journals that published different responses to at least 2 papers. A subset of published responses revealed conflicting explanations for the wrongly identified control reagent, despite 30/31 papers obtaining their gene knockdown reagents from the same external supplier. Viewed collectively, different journal responses to human gene knockdown publications with a common reagent error type suggest that editorial staff require more support to interpret post-publication notifications of incorrect nucleotide sequence reagents. We propose a draft template to facilitate the communication, interpretation and investigation of published errors, including errors affecting research reagents.

MicroRNA-147b suppresses the proliferation and invasion of non-small-cell lung cancer cells through downregulation of Wnt/β-catenin signalling via targeting of RPS15A

Deregulation of microRNAs (miRNAs) leads to malignant growth and aggressive invasion during cancer occurrence and progression. miR-147b has emerged as one of the cancer-related miRNAs that are dysregulated in multiple cancers. Yet, the relevance of miR-147b in non-small-cell lung cancer (NSCLC) remains unclear. In the present study, we aimed to report the biological function and signalling pathways mediated by miR-147b in NSCLC. Our results demonstrate that miR-147b expression is significantly downregulated in NSCLC tissues and cell lines. Overexpression of miR-147b decreased the proliferative ability, colony-forming capability, and invasive potential of NSCLC cells. Notably, our study identified ribosomal protein S15A (RPS15A), an oncogene in NSCLC, as a target gene of miR-147b. Our results showed that miR-147b negatively modulates RPS15A expression in NSCLC cells. An inverse correlation between miR-147b and RPS15A was evidenced in NSCLC specimens. Moreover, miR-147b overexpression downregulated the activation of Wnt/β-catenin signalling via targeting of RPS15A. Overexpression of RPS15A partially reversed the miR-147b-mediated antitumour effect in NSCLC cells. Collectively, these findings reveal that miR-147b restricts the proliferation and invasion of NSCLC cells by inhibiting RPS15A-induced Wnt/β-catenin signalling and suggest that the miR-147b/RPS15A/Wnt/β-catenin axis is an important regulatory mechanism for malignant progression of NSCLC.

Ribosomal protein small subunit 15A (RPS15A) inhibits the apoptosis of breast cancer MDA-MB-231 cells via upregulating phosphorylated ERK1/2, Bad, and Chk1

AIM

To detect the expression and identify the role of Ribosomal protein S15A (RPS15A) in human breast cancer (BC).

METHODS

Immunohistochemistry (IHC) was carried out for detecting the levels of RPS15A protein. Quantitative PCR was used to evaluate the mRNA level of RPS15A in one normal breast and three BC cell lines. Lentivirus-mediated shRNA targeting RPS15A was designed to investigate the impact of silencing RPS15A in MDA-MB-231 cell.

RESULTS

Higher RPS15A expression was detected in tumor tissues than in para-cancer tissues, and higher RPS15A expression was related to larger tumor size and higher TNM stage. Also, RPS15A mRNA expression in all three BC cell lines was higher than that in normal breast cell (all P < .005). Further, RPS15A knockdown significantly suppressed MDA-MB-231 cell proliferation and induced apoptosis. Moreover, RPS15A knockdown increased the caspase-3/-7 activity, and suppressed the phosphorylated levels of ERK1/2, Bad, and Chk1 (all P < .01).

CONCLUSION

RPS15A inhibits apoptosis via upregulating phosphorylated ERK1/2, Bad, and Chk1 in MDA-MB-231 cell line.

Overexpression of microRNA-519d-3p suppressed the growth of pancreatic cancer cells by inhibiting ribosomal protein S15A-mediated Wnt/β-catenin signaling

Ribosomal protein S15A (RPS15A) has emerged as a novel oncogene of various human cancers. However, whether RPS15A is involved in pancreatic cancer remains unclear. In this study, we aimed to investigate the potential relevance of RPS15A in pancreatic cancer and elucidate the underlying regulatory mechanism. We found that RPS15A expression was significantly up-regulated in pancreatic cancer cell lines. RPS15A knockdown resulted in a decrease of cell proliferation and colony formation, and induced cell cycle arrest in G0/G1 phases of pancreatic cancer cells in vitro. In addition, RPS15A knockdown down-regulated β-catenin expression and blocked the activation of Wnt signaling. Notably, RPS15A was identified as a target gene of microRNA-519d-3p (miR-519d-3p), a tumor suppressive miRNA. Further data showed that miR-519d-3p negatively regulated RPS15A expression in pancreatic cancer cells. Moreover, miR-591d-3p expression was significantly decreased in pancreatic cancer cell lines and tissues and was inversely correlated with RPS15A expression. The overexpression of miR-519d-3p significantly inhibited the proliferation and Wnt/β-catenin signaling in pancreatic cancer cells, mimicking the similar effect of RPS15A knockdown. However, restoration of RPS15A expression partially reversed the antitumor effect of miR-519d-3p. Taken together, our results demonstrate that RPS15A knockdown or RPS15A inhibition by miR-519d-3p suppresses the growth of pancreatic cancer cells associated with the inhibition of Wnt/β-catenin signaling. Our study suggests that the miR-519d-3p/RPS15A/Wnt/β-catenin regulation axis plays an important role in the progression of pancreatic cancer and may serve as potential targets for treatment of pancreatic cancer.

RPS15A promotes gastric cancer progression via activation of the Akt/IKK-β/NF-κB signalling pathway

This study aimed to investigate the clinical significance, potential biological function and underlying mechanism of RPS15A in gastric cancer (GC) progression. RPS15A expression was detected in 40 pairs of GC tissues and matched normal gastric mucosae (MNGM) using qRT‐PCR analysis. Immunohistochemistry assay was conducted using a tissue microarray including 186 primary GC samples to characterize the clinical significance of RPS15A. A series of in vitro and in vivo assays were performed to elucidate the biological function of RPS15A in GC development and underlying molecular mechanisms. The expression of RPS15A was significantly up‐regulated in GC samples compared to MNGM, and its expression was closely related to TNM stage, tumour size, differentiation, lymph node metastasis and poor patient survival. Ectopic expression of RPS15A markedly enhanced the proliferation and metastasis of GC cells both in vitro and in vivo. RPS15A overexpression also promoted the epithelial‐mesenchymal transition (EMT) phenotype formation of GC cells. Investigations of underlying mechanisms found that RPS15A activated the NF‐κB signalling pathway by inducing the nuclear translocation and phosphorylation of the p65 NF‐κB subunit, transactivation of NF‐κB reporter and up‐regulating target genes of this pathway. In addition, RPS15A overexpression activated, while RPS15A knockdown inhibited the Akt/IKK‐β signalling axis in GC cells. And both Akt inhibitor LY294002 and IKK inhibitor Bay117082 neutralized the p65 and p‐p65 nuclear translocation induced by RPS15A overexpression. Collectively, our findings suggest that RPS15A activates the NF‐κB pathway through Akt/IKK‐β signalling axis, and consequently promotes EMT and GC metastasis. This newly identified RPS15A/Akt/IKK‐β/NF‐κB signalling pathway may be a potential therapeutic target to prevent GC progression.

RPS15a Silencing Suppresses Cell Proliferation and Migration of Gastric Cancer

PURPOSE

Information on the possible role of the ribosomal protein S15a (RPS15a) in gastric cancer is scarce. The aim of this study was to evaluate the impact of RPS15a gene expression on the growth and cell cycle of gastric cancer cells in vitro and in vivo.

MATERIALS AND METHODS

RPS15a mRNA expression was examined in cancer tissues and their corresponding adjacent normal tissues of 40 gastric adenocarcinoma patients. Next, RPS15a was knocked down using a lentivirus-mediated RNA interference (short hairpin RNA) system in the gastric cancer cell line BGC823. The effect of RPS15a knockdown was examined using CCK-8 assay, cell scratch test, colony formation assay, and flow cytometry. Finally, in nude mice, a tumorigenicity test was performed, and the tumor volume and weight were measured.

RESULTS

RPS15a expression in tumor tissue was significantly greater than that in the adjacent normal tissue of gastric cancer patients. After RPS15a silencing, the BGC823 cell proliferation rate decreased significantly; most cells were arrested in the G0/G1 phase, cell growth was inhibited, and the migration rate was decreased. Colony formation assay showed that the number and size of clones in the RPS15a-silenced cells were fewer and smaller, compared to control cells. The nude mouse tumorigenicity test showed that RPS15a silencing had an inhibitory effect on tumor volume and mice weight.

CONCLUSION

The present study found RPS15a expression to be higher in gastric tumors and its silencing in gastric cancer cells to inhibit the proliferation, growth, and migration thereof. Accordingly, RPS15a may be considered as a potential therapeutic target in gastric cancer.

The roles of moonlight ribosomal proteins in the development of human cancers

"Moonlighting protein" is a term used to define a single protein with multiple functions and different activities that are not derived from gene fusions, multiple RNA splicing, or the proteolytic activity of promiscuous enzymes. Different proteinous constituents of ribosomes have been shown to have important moonlighting extra-ribosomal functions. In this review, we introduce the impact of key moonlight ribosomal proteins and dependent signal transduction in the initiation and progression of various cancers. As a future perspective, the potential role of these moonlight ribosomal proteins in the diagnosis, prognosis, and development of novel strategies to improve the efficacy of therapies for human cancers has been suggested.

Knockdown of ribosomal protein S15A inhibits proliferation of breast cancer cells through induction of apoptosis in vitro

To explore the role of ribosomal protein S15A (RPS15A) in breast cancer. The Oncomine database was used to compare the expression of RPS15A in human breast cancer tissues and normal tissues. RPS15A in breast cancer cell line ZR-75-30 and BT474 was specifically knocked down using lentivirus-mediated short hairpin RNAs (shRNAs). RPS15A knockdown efficiency was validated by quantitative polymerase chain reaction and western blot analysis. Subsequently, the functional effects of RPS15A on proliferation of breast cancer cells were investigated by MTT, colony formation and flow cytometry assays. Functional analysis indicated that RPS15A knockdown could inhibit cell proliferation, induced cell cycle arrest and apoptosis. Mechanism analysis revealed RPS15A mediated apoptosis via activating of caspase-3 and PARP cleavage, upregulating of Bad and BAX and downregulating of Bcl-2. Our preliminary study highlighted the importance of RPS15A in breast cancer growth. The inhibition of RPS15A may be a promising therapeutic target for breast cancer treatment.

MicroRNA-29 family functions as a tumor suppressor by targeting RPS15A and regulating cell cycle in hepatocellular carcinoma

Growing evidence shows that miRNA plays an important role in the development and progression of cancer. In this study, we found that the expression levels of miR-29 family were dramatically decreased in hepatocellular carcinoma (HCC) cell lines and clinical tissues. Then, we demonstrated that ectopic expression of miR-29 family could significantly suppress cell proliferation and induce apoptosis in HCC cells. Luciferase assay together with western blot assay confirmed that miR-29 family bound directly to the 3'-untranslated region (3'-UTR) of RPS15A and reduced the expression of RPS15A. In addition, the cell cycle related gene including cyclinA, cyclin D1 and p21 were also down-regulated when increased the expression of miR-29 family, which is similar as silencing RPS15A expression. Moreover, co-transfection of miR-29 mimics with 3'UTR-deleted RPS15A could rescue the expressions of cyclin A and cyclin D1 while down-regulate the p21 expression. In conclusion, miR-29 family functions as a novel tumor suppressor in HCC by regulate cell growth and cell cycle through binding to RPS15A 3'UTR. These findings may be utilized in developing novel therapeutic tools for HCC.

Highly expressed ribosomal protein L34 indicates poor prognosis in osteosarcoma and its knockdown suppresses osteosarcoma proliferation probably through translational control

Osteosarcoma has devastating health implications on children and adolescents. However, due to its low incidence and high tumor heterogeneity, it is hard to achieve any further improvements in therapy and overall survival. Ribosomal protein L34 (RPL34) has been increasingly recognized to promote the proliferation of malignant cells, but its role in osteosarcoma has not been investigated. In this study, real-time quantitative PCR (RT-qPCR) and immunohistochemistry revealed that RPL34 was highly expressed in osteosarcoma tissues when compared to adjacent tissues and normal bone tissues. Survival analysis showed that high expression of RPL34 predicted a poor prognosis for osteosarcoma patients. Knockdown of RPL34 in Saos-2 cells via lentivirus-mediated small interfering RNA (siRNA) significantly inhibited cell proliferation, induced cell apoptosis and G2/M phase arrest. Moreover, screening of transcription factors using University of California Santa Cruz (UCSC) Genome Browser, protein-protein interaction (PPI) network analysis, Gene Ontology (GO) and pathway enrichment analysis revealed that MYC participates in the transcriptional regulation of RPL34, which interacts with the subunits of eukaryotic translation initiation factor 3 (eIF3) and probably involves the translational control of growth-promoting proteins. Our findings suggest that RPL34 plays an important role in the proliferation of osteosarcoma cells.

Knockdown of ribosomal protein S15A induces human glioblastoma cell apoptosis

Background

RPS15A is a ribosome protein that is highly conserved in many organisms from yeast to human. A number of studies implied its role in promoting cancer cell growth.

Methods

Here, we firstly conducted RPS15A gene expression analysis in brain cancer using Oncomine database and found RPS15A was remarkably overexpressed in glioblastoma (GBM) compared with that in normal tissues. Then, the expression of RPS15A was specifically silenced in GBM cell line U251 using lentiviral-mediated RNA interference technique. We further investigated the effect of RPS15A knockdown in U251 cells using MTT assay, colony formation test, and flow cytometry analysis. We detected the protein level of Bcl-2 and poly (ADP-ribose) polymerase (PARP) as well as activation of caspase-3.

Results

Our results showed that the knockdown of RPS15A could inhibit cancer cell growth and colony formation in vitro, as well as induced cell cycle arrest at G0/G1 phase and cell apoptosis. In addition, Western blot analysis indicated that the knockdown of RPS15A could significantly inhibit bcl-2 and activate caspase-3 and PARP.

Conclusions

Our findings suggest RPS15A may play an important role in the progression of GBM and lentiviral-mediated silencing of RPS15A could be an effective tool in GBM treatment.

Ribosomal protein S15A promotes malignant transformation and predicts poor outcome in colorectal cancer through misregulation of p53 signaling pathway

Ribosomal protein S15A (RPS15A), which has been identified as a highly conserved 40S ribosomal protein, is essential for cell survival and proliferation. The present study evaluated the functional role of RPS15A in colorectal cancer (CRC), and our investigation found that RPS15A was highly expressed in a cohort of human CRC. High RPS15A expression was associated with older age (P=0.035), not receiving preoperative neoadjuvant treatment (P=0.048), higher primary pN stage (P=0.007) and slightly more synchronous distant metastases (P=0.058). The Cox univariate and multivariate hazard regression analysis revealed that higher expression of RPS15A led to a reduction of overall survival rate in CRC, indicating that enhanced RPS15A expression functions as an independent risk factor for the prognosis of CRC patients (P<0.001). Cell based analysis showed that RPS15A was widely expressed in human CRC cell lines. Knockdown of RPS15A significantly suppressed cell proliferation and colony formation in HCT116 and DLD-1 cells, and induced cell cycle arrest at G0/G1 phase. Genechip analysis suggested that knockdown of RPS15A might affect the p53 signaling pathway. Further study indicated that RPS15A knockdown upregulated p53 and p21 expression whereas downregulated CDK1 expression. In summary, the present study identified RPS15A as a novel univariate prognostic factor predicting a poor outcome in CRC patients. The RPS15A overexpression induced by malignant transformation of CRC might function through the p53 signaling pathway.