FTSJ2, a heat shock-inducible mitochondrial protein, suppresses cell invasion and migration

Circ_100549 promotes tumor progression in lung adenocarcinoma through upregulation of BIRC6

Lung adenocarcinoma (LUAD) is a subtype of lung cancer with high incidence and mortality globally. Emerging evidence suggests that circular RNAs (circRNAs) exert critical functions in human cancers, including LUAD. CircRNA_100549 (circ_100549) has been reported to be significantly upregulated in non-small cell lung cancer (NSCLC) samples, while its role in modulating LUAD progression remains to be explored. The current study aims at investigating the functional roles of circ_100549 in LUAD and its downstream molecular mechanism. First, we found that the expression of circ_100549 was higher in LUAD cell lines. Loss-of-function assays verified that depletion of circ_100549 repressed LUAD cell proliferation but accelerated cell apoptosis. Furthermore, in vivo experiments demonstrated that silencing of circ_100549 suppressed tumor growth. Subsequently, based on database analysis, we carried out a series of experiments to explore the mechanisms and effects of circ_100549 underlying LUAD progression, including RNA-binding protein immunoprecipitation (RIP), RNA/DNA pull-down, luciferase reporter, and chromatin immunoprecipitation (ChIP) assays. The results indicated that circ_100549 serves as a ceRNA by sponging miR-95-5p to upregulate BPTF expression, thus upregulating BIRC6 expression at a transcriptional level in LUAD. In summary, our study demonstrated that circ_100549 facilitates LUAD progression by upregulating BIRC6 expression.

RNA Methyltransferase FTSJ3 Regulates the Type I Interferon Pathway to Promote Hepatocellular Carcinoma Immune Evasion

Immunotherapies such as immune checkpoint blockade have achieved remarkable success in treating cancer. Unfortunately, response rates have been limited in multiple cancers including hepatocellular carcinoma (HCC). The critical function of epigenetics in tumor immune evasion and antitumor immunity supports harnessing epigenetic regulators as a potential strategy to enhance the efficacy of immunotherapy. Here, we discovered a tumor-promoting function of FTSJ3, an RNA 2'-O-methyltransferase, in HCC by suppressing antitumor immune responses. FTSJ3 was upregulated in hepatocellular carcinoma, and high FTSJ3 expression correlated with reduced patient survival. Deletion of FTSJ3 blocked HCC growth and induced robust antitumor immune responses. Mechanistically, FTSJ3 suppressed double-stranded RNA (dsRNA)-induced IFNβ signaling in a 2'-O-methyltransferase manner. Deletion of RNA sensors in HCC cells or systemic knockout of type I IFN receptor IFNAR in mice rescued the in vivo tumor growth defect caused by FTSJ3 deficiency, indicating that FTSJ3 deletion suppresses tumor growth by activating the RNA sensor-mediated type I IFN pathway. Furthermore, FTSJ3 deletion significantly enhanced the efficacy of programmed cell death protein 1 (PD-1) immune checkpoint blockade. The combination of FTSJ3 deficiency and anti-PD-1 antibody treatment effectively eradicated tumors and increased the survival time. In conclusion, this study reveals an epigenetic mechanism of tumor immune evasion and, importantly, suggests FTSJ3-targeting therapies as potential approach to overcome immunotherapy resistance in patients with HCC.

SIGNIFICANCE

Hepatocellular carcinoma cells use 2'-O-methylation catalyzed by FTSJ3 for immune evasion by suppressing abnormal dsRNA-mediated type I IFN responses, providing a potential target to activate antitumor immunity and enhance immunotherapy efficacy.

Identification of a Risk Locus at 7p22.3 for Schizophrenia and Bipolar Disorder in East Asian Populations

Background: Shared psychopathological features and mechanisms have been observed between schizophrenia (SZ) and bipolar disorder (BD), but their common risk genes and full genetic architectures remain to be fully characterized. The genome-wide association study (GWAS) datasets offer the opportunity to explore this scientific question using combined genetic data from enormous samples, ultimately allowing a better understanding of the onset and development of these illnesses.

Methods: We have herein performed a genome-wide meta-analysis in two GWAS datasets of SZ and BD respectively (24,600 cases and 40,012 controls in total, discovery sample), followed by replication analyses in an independent sample of 4,918 SZ cases and 5,506 controls of Han Chinese origin (replication sample). The risk SNPs were then explored for their correlations with mRNA expression of nearby genes in multiple expression quantitative trait loci (eQTL) datasets.

Results: The single nucleotide polymorphisms (SNPs) rs1637749 and rs3800908 at 7p22.3 region were significant in both discovery and replication samples, and exhibited genome-wide significant associations when combining all East Asian SZ and BD samples (29,518 cases and 45,518 controls). The risk SNPs were also significant in GWAS of SZ and BD among Europeans. Both risk SNPs significantly predicted lower expression of MRM2 in the whole blood and brain samples in multiple datasets, which was consistent with its reduced mRNA level in the brains of SZ patients compared with normal controls. The risk SNPs were also associated with MAD1L1 expression in the whole blood sample.

Discussion: We have identified a novel genome-wide risk locus associated with SZ and BD in East Asians, adding further support for the putative common genetic risk of the two illnesses. Our study also highlights the necessity and importance of mining public datasets to explore risk genes for complex psychiatric diseases.

A novel risk signature with 6 RNA binding proteins for prognosis prediction in patients with glioblastoma

Recent studies suggested that RNA binding proteins (RBPs) were related to the tumorigenesis and progression of glioma. This study was conducted to identify prognostic RBPs of glioblastoma (GBM) and construct an RBP signature to predict the prognosis of GBM.Univariate Cox regression analysis was carried out to identify the RBPs associated with overall survival of GBM in the The Cancer Genome Atlas (TCGA), GSE16011, and Repository for Molecular Brain Neoplasia data (Rembrandt) datasets, respectively. Overlapping RBPs from the TCGA, GSE16011, and Rembrandt datasets were selected. The biological role of prognostic RBPs was assessed by Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and protein-protein interaction analyses. Least absolute shrinkage and selection operator regression analysis and multivariate Cox regression analysis were used to construct an RBP-related risk signature. The prognostic value of RBP signature was measured by Kaplan-Meier method and time-dependent receiver operating characteristic curve. A nomogram based on independent prognostic factors was established to predict survival for GBM. The CGGA cohort was used as the validation cohort for external validation.This study identified 27 RBPs associated with the prognosis of GBM and constructed a 6-RPBs signature. Kaplan-Meier curves suggested that high-risk score was associated with a poor prognosis. Area under the curve of 1-, 3-, and 5-year overall survival was 0.618, 0.728, and 0.833 for TCGA cohort, 0.655, 0.909, and 0.911 for GSE16011 cohort, and 0.665, 0.792, and 0.781 for Rembrandt cohort, respectively. A nomogram with 4 parameters (age, chemotherapy, O6-methylguanine-DNA methyltransferase promoter status, and risk score) was constructed. The calibration curve showed that the nomogram prediction was in good agreement with the actual observation.The 6-RBPs signature could effectively predict the prognosis of GBM, and our findings supplemented the prognostic index of GBM to a certain extent.

Postmortem Diagnosis of Heart-hand Syndrome Associated With a 7p22.1p22.3 Deletion in a 16-week-old Fetus

We report a male fetus with a 6.8 Mb deletion on chromosome 7p22.1p22.3 at 16 weeks of gestation. The fetus presented a heart-hand syndrome with great artery malposition, bilateral radial ray deficiency, a single pelvic kidney, and growth retardation. This deletion involves a minimal deleted region for cardiac malformation and the RAC1 gene, previously described in limb anomalies in mice. This fetus is the third human case with limb defects and RAC1 deletion.

RNA 2'-O-Methylation (Nm) Modification in Human Diseases

Nm (2'-O-methylation) is one of the most common modifications in the RNA world. It has the potential to influence the RNA molecules in multiple ways, such as structure, stability, and interactions, and to play a role in various cellular processes from epigenetic gene regulation, through translation to self versus non-self recognition. Yet, building scientific knowledge on the Nm matter has been hampered for a long time by the challenges in detecting and mapping this modification. Today, with the latest advancements in the area, more and more Nm sites are discovered on RNAs (tRNA, rRNA, mRNA, and small non-coding RNA) and linked to normal or pathological conditions. This review aims to synthesize the Nm-associated human diseases known to date and to tackle potential indirect links to some other biological defects.

A novel gene signature based on five glioblastoma stem-like cell relevant genes predicts the survival of primary glioblastoma

PURPOSE

Primary glioblastoma (pGBM) is the most common and lethal type of neoplasms in the central nervous system, while the existing biomarkers, lacking consideration on the stemness changes of GBM cells, are not specific enough to predict the complex prognosis respectively. We aimed to build a high-efficiency prediction gene signature related to GBM cell stemness and investigate its prognostic value in primary glioblastoma.

METHODS

Differentially expressed genes were screened in GSE23806 database. The selected genes were then verified by univariate Cox regression in 591 patients from four enormous independent databases, including the Chinese Glioma Genome Atlas (CGGA), TCGA, REMBRANDT and GSE16011. Finally, the intersected genes were included to build the gene signature. GO analysis and GSEA were carried out to explore the bioinformatic implication.

RESULTS

The novel five-gene signature was used to identify high- and low-risk groups in the four databases, and the high-risk group showed notably poorer prognosis (P < 0.05). Gene ontology (GO) terms including "immune response", "apoptotic process", and "angiogenesis" were picked out by GO analysis and GSEA, which revealed that the gene signature was highly possibly related to the stemness of GSCs and predicting the prognosis of GBM effectively.

CONCLUSION

We built a gene signature with five glioblastoma stem-like cell (GSC) relevant genes, and predicted the survival in four independent databases effectively, which is possibly related to the stemness of GSCs in pGBM. Several GO terms were investigated to be correlated to the signature. The signature can predict the prognosis of glioblastoma efficiently.

Using Dual Fluorescence Reporting Genes to Establish an In Vivo Imaging Model of Orthotopic Lung Adenocarcinoma in Mice

PURPOSE

Lung adenocarcinoma is characterized by a poor prognosis and high mortality worldwide. In this study, we purposed to use the live imaging techniques and a reporter gene that generates highly penetrative near-infrared (NIR) fluorescence to establish a preclinical animal model that allows in vivo monitoring of lung cancer development and provides a non-invasive tool for the research on lung cancer pathogenesis and therapeutic efficacy.

PROCEDURES

A human lung adenocarcinoma cell line (A549), which stably expressed the dual fluorescence reporting gene (pCAG-iRFP-2A-Venus), was used to generate subcutaneous or orthotopic lung cancer in nude mice. Cancer development was evaluated by live imaging via the NIR fluorescent signals from iRFP, and the signals were verified ex vivo by the green fluorescence of Venus from the gross lung. The tumor-bearing mice received miR-16 nucleic acid therapy by intranasal administration to demonstrate therapeutic efficacy in this live imaging system.

RESULTS

For the subcutaneous xenografts, the detection of iRFP fluorescent signals revealed delicate changes occurring during tumor growth that are not distinguishable by conventional methods of tumor measurement. For the orthotopic xenografts, the positive correlation between the in vivo iRFP signal from mice chests and the ex vivo green fluorescent signal from gross lung tumors and the results of the suppressed tumorigenesis by miR-16 treatment indicated that lung tumor size can be accurately quantified by the emission of NIR fluorescence. In addition, orthotopic lung tumor localization can be accurately visualized using iRFP fluorescence tomography in vivo, thus revealing the trafficking of lung tumor cells.

CONCLUSIONS

We introduced a novel dual fluorescence lung cancer model that provides a non-invasive option for preclinical research via the use of NIR fluorescence in live imaging of lung.

MiR-542-3p exerts tumor suppressive functions in non-small cell lung cancer cells by upregulating FTSJ2

AIMS

Up-regulation or down-regulation of microRNAs (miRNAs) has been found in non-small cell lung cancer (NSCLC). However, the role and mechanism of regulation of miR-542-3p in NSCLC is still unclear. This study aimed at investigating the primary biological function of miR-542-3p and FTSJ2 in NSCLC tumorigenesis and the correlation of miR-542-3p and FTSJ2 in NSCLC.

MAIN METHODS

Our present results showed that miR-542-3p was down-regulated in NSCLC tissues and cancer cells. Overexpression of miR-542-3p inhibited cell proliferation, cell migration, cell cycle, EMT process and tumor growth in vitro, and induced cell apoptosis by MTT assay, colony formation assay, transwell migration assay, flow cytometry assay, RT-qPCR assay, western blot experiment and vivo model assay; miR-542-3p directly bound to the 3'UTR of FTSJ2 and upregulated FTSJ2 both mRNA and protein level by EGFP reporter assay, RT-qPCR and western blot analysis in NSCLC cells. FTSJ2 also reduced the aggressiveness of NSCLC cells.

KEY FINDINGS

In short, miR-542-3p functions as a suppressor gene by targeting and upregulating FTSJ2, thus inhibiting the malignancy of NSCLC cells.

SIGNIFICANCE

According to the results, miRNA-542-3p and its targeted FTSJ2 may be indispensable as a predictive biomarker of the response to the treatment in patients with NSCLC.

Factors That Shape Eukaryotic tRNAomes: Processing, Modification and Anticodon-Codon Use

Transfer RNAs (tRNAs) contain sequence diversity beyond their anticodons and the large variety of nucleotide modifications found in all kingdoms of life. Some modifications stabilize structure and fit in the ribosome whereas those to the anticodon loop modulate messenger RNA (mRNA) decoding activity more directly. The identities of tRNAs with some universal anticodon loop modifications vary among distant and parallel species, likely to accommodate fine tuning for their translation systems. This plasticity in positions 34 (wobble) and 37 is reflected in codon use bias. Here, we review convergent evidence that suggest that expansion of the eukaryotic tRNAome was supported by its dedicated RNA polymerase III transcription system and coupling to the precursor-tRNA chaperone, La protein. We also review aspects of eukaryotic tRNAome evolution involving G34/A34 anticodon-sparing, relation to A34 modification to inosine, biased codon use and regulatory information in the redundancy (synonymous) component of the genetic code. We then review interdependent anticodon loop modifications involving position 37 in eukaryotes. This includes the eukaryote-specific tRNA modification, 3-methylcytidine-32 (m³C₃₂) and the responsible gene, TRM140 and homologs which were duplicated and subspecialized for isoacceptor-specific substrates and dependence on i⁶A₃₇ or t⁶A₃₇. The genetics of tRNA function is relevant to health directly and as disease modifiers.

Lung tumorigenesis induced by human vascular endothelial growth factor (hVEGF)-A165 overexpression in transgenic mice and amelioration of tumor formation by miR-16

Many studies have shown that vascular endothelial growth factor (VEGF), especially the human VEGF-A₁₆₅ (hVEGF-A₁₆₅) isoform, is a key proangiogenic factor that is overexpressed in lung cancer. We generated transgenic mice that overexpresses hVEGF-A₁₆₅ in lung-specific Clara cells to investigate the development of pulmonary adenocarcinoma. In this study, three transgenic mouse strains were produced by pronuclear microinjection, and Southern blot analysis indicated similar patterns of the foreign gene within the genomes of the transgenic founder mice and their offspring. Accordingly, hVegf-A₁₆₅ mRNA was expressed specifically in the lung tissue of the transgenic mice. Histopathological examination of the lung tissues of the transgenic mice showed that hVEGF-A₁₆₅ overexpression induced bronchial inflammation, fibrosis, cysts, and adenoma. Pathological section and magnetic resonance imaging (MRI) analyses demonstrated a positive correlation between the development of pulmonary cancer and hVEGF expression levels, which were determined by immunohistochemistry, qRT-PCR, and western blot analyses. Gene expression profiling by cDNA microarray revealed a set of up-regulated genes (hvegf-A₁₆₅, cyclin b1, cdc2, egfr, mmp9, nrp-1, and kdr) in VEGF tumors compared with wild-type lung tissues. In addition, overexpressing hVEGF-A₁₆₅ in Clara cells increases CD105, fibrogenic genes (collagen α1, α-SMA, TGF-β1, and TIMP1), and inflammatory cytokines (IL-1, IL-6, and TNF-α) in the lungs of hVEGF-A₁₆₅-overexpressing transgenic mice as compared to wild-type mice. We further demonstrated that the intranasal administration of microRNA-16 (miR-16) inhibited lung tumor growth by suppressing VEGF expression via the intrinsic and extrinsic apoptotic pathways. In conclusion, hVEGF-A₁₆₅ transgenic mice exhibited complex alterations in gene expression and tumorigenesis and may be a relevant model for studying VEGF-targeted therapies in lung adenocarcinoma.

Methylation-silencing RCC1 expression is associated with tumorigenesis and depth of invasion in gastric cancer

INTRODUCTION

Regulator of chromosome condensation 1 (RCC1) is a critical cell cycle regulator. We firstly identified RCC1 gene hypermethylation in gastric tumor tissues using the differential methylation hybridization (DMH) microarray, but the role of RCC1 in the pathogenesis of gastric carcinoma is largely unknown.

METHODS

Three gastric cancer cell lines (AGS, MKN45, and TSGH9201) were used to analyze RCC1 gene methylation, mRNA and protein expressions. Furthermore, 85 pairs of matched human gastric carcinoma samples in a tissue microarray were used to analyze RCC1 expression by immunohistochemistry staining.

RESULTS

A differential methylation pattern was found in TSGH9201 (100%), MKN45 (87%), and AGS (62%) cell lines at the 9th CpG site of RCC1 exon 1. RCC1 mRNA and protein expressions in AGS cells were significantly higher than in TSGH9201 and MKN45 cell lines (P < 0.05). Tissue array data showed that RCC1 expression was detected in 21% (18/85) of gastric carcinoma tissues and in 80% (76/95) of adjacent non-tumor tissues. The expression of RCC1 in gastric carcinoma tissues was significantly lower than in adjacent non-tumor tissues (P < 0.001). Furthermore, an association between RCC1 expression and clinicopathological features showed that RCC1 expression was closely correlated with tumor differentiation and depth of invasion (P < 0.05).

CONCLUSIONS

Our data indicate that RCC1 expression is frequently lost in poorly differentiated gastric cell lines and gastric carcinoma tissues. Loss of RCC1 expression is correlated with tumor differentiation and depth of invasion. These findings suggest that RCC1 may play a tumor suppressor role in gastric carcinoma.