Intragenic β-synuclein rearrangements in malignancy

The synuclein family, consisting of α-, β-, and γ-synuclein, is primarily expressed in neurons. Mutations of α- and β-synuclein have been linked to Parkinson's disease and dementia with Lewy bodies, respectively. Recent studies have shown that synucleins are upregulated in various tumors, including breast, ovarian, meningioma, and melanoma, and high synuclein expression is associated with poor prognosis and drug resistance. We report a novel rearrangement of β-synuclein in a pediatric T-cell acute lymphoblastic leukemia (T-ALL) case, where β-synuclein (SNCB) is fused in-frame with ETS variant transcription factor 6 (ETV6), a gene frequently rearranged in acute leukemia including acute myeloid leukemia (AML), B-cell acute lymphoblastic leukemia (B-ALL), and T-ALL. An additional case of β-synuclein rearrangement was identified in a squamous cell carcinoma of the lung through analysis of the public TCGA database. Both rearrangements involve the C-terminal of β-synuclein. Since β-synuclein shares extensive amino acid similarities with α-synuclein and α-synuclein binds to 14-3-3, an important regulator of apoptosis, the rearranged β-synuclein may contribute to tumorigenesis by deregulating apoptosis. In addition, overexpression of synucleins has been shown to increase cell proliferation, suggesting that the rearranged β-synuclein may also deregulate the cell cycle.

Circular RNA circ_0002360 regulates the Taxol resistance and malignant behaviors of Taxol-resistant non-small cell lung cancer cells by microRNA-585-3p-dependent modulation of G protein regulated inducer of neurite outgrowth 1

Drug resistance has become the major obstacle for the treatment of non-small cell lung cancer (NSCLC). Circular RNAs (circRNAs) are tightly linked to the development of drug resistance of NSCLC. Herein, we tested the function of circ_0002360 in the Taxol resistance of NSCLC. Circ_0002360, microRNA (miR)-585-3p and G protein regulated inducer of neurite outgrowth 1 (GPRIN1) were quantified by quantitative real-time PCR (qRT-PCR). To identify the circular structure of circ_0002360, RNase R digestion was applied. To detect cell proliferation, colony formation and 5-ethynyl-2’-deoxyuridine (EdU) assays were used. For assessment of cell apoptosis, flow cytometry was adopted. For motility and invasion analyses, transwell assay was employed. Our data showed that circ_0002360 was mainly located in the cytoplasm and was highly expressed in the Taxol-resistant NSCLC. Silencing of circ_0002360 inhibited cell Taxol resistance, proliferation, motility, and invasiveness and induced apoptosis in vitro. MiR-585-3p was underexpressed in Taxol-resistant NSCLC and was targeted by circ_0002360. MiR-585-3p knockdown alleviated the influence of circ_0002360 silence on Taxol-resistant cells. GPRIN1 was directly targeted by miR-585-3p. The influence of miR-585-3p on cell Taxol resistance and functional behaviors was reversed by GPRIN1 overexpression. Moreover, circ_0002360 modulated GPRIN1 through miR-585-3p. Additionally, silencing of circ_0002360 weakened the growth of xenografts in vivo. Our study demonstrated that silencing of circ_0002360 enhanced the Taxol sensitivity and suppressed the malignant behaviors of Taxol-resistant NSCLC cells by miR-585-3p/GPRIN1 axis, providing novel targets for improving the anti-tumor efficacy of Taxol in NSCLC.

miR-654-5p promotes gastric cancer progression via the GPRIN1/NF-κB pathway

Background

Gastric carcinoma (GC) ranks the fifth most common cancer worldwide, with high incidence and mortality rates. Numerous microRNAs (miRNAs), including miR-654-5p, have been implicated in the pathophysiological processes of tumorigenesis. Nevertheless, the mechanism of miR-654-5p in GC is unclear.

Objectives

Our study is devoted to exploring the function and molecular mechanism of miR-654-5p on the malignant cell behaviors of GC.

Methods

The gene expression was detected by reverse transcription quantitative polymerase chain reaction. GC cell proliferation and motion were assessed by colony formation assay and transwell assay. The binding capacity between miR-654-5p and G protein-regulated inducer of neurite outgrowth 1 (GPRIN1) was explored by luciferase reporter and RNA pulldown assays. The protein levels were detected by Western blotting.

Results

miR-654-5p expression was higher in GC cells and tissues than control cells and tissues. miR-654-5p promoted GC cell growth and motion. Moreover, our findings showed that miR-654-5p was bound with GPRIN1. Importantly, downregulation of GPRIN1 rescued the inhibitory influence of miR-654-5p knockdown on GC cell malignant behaviors. Additionally, miR-654-5p activated the nuclear factor kappa-B (NF-κB) pathway by regulation of GPRIN1.

Conclusions

miR-654-5p facilitated cell proliferation, migration, and invasion in GC via targeting the GPRIN1 to activate the NF-κB pathway.

A novel lncRNA-miRNA-mRNA competing endogenous RNA regulatory network in lung adenocarcinoma and kidney renal papillary cell carcinoma

Background

GPRIN1 may be a novel tumor regulator, but its role and mechanism in tumors are still unclear.

Methods

First, a pan‐cancer correlation analysis was conducted on the expression and prognosis of GPRIN1 based on the data downloaded from The Cancer Genome Atlas (TCGA) database. Second, the Starbase database was used to predict the upstream miRNAs and lncRNAs of GPRIN1, and the expression analysis, survival analysis, and correlation analysis were performed to screen the microRNA (miRNAs)/long non‐coding RNAs (lncRNAs) that had a correlation with kidney renal papillary cell carcinoma (KIRP) or lung adenocarcinoma (LUAD). Third, the CIBERSORT algorithm was employed to calculate the proportion of various types of immune cells, and then the R packages were used for evaluating the relation between GPRIN1 expression and tumor immune cell infiltration as well as between GPRIN1 and the immune cell biomarker. Finally, the correlation analysis was made on GPRIN1 and immune checkpoints (CD274, CTLA4, and PDCD1).

Results

The pan‐cancer analysis suggested that GPRIN1 was up‐expressed in KIRP and LUAD, and it correlated with poor prognosis. LINC00894/MMP25‐AS1/SNHG1/LINC02298/MIR193BHG‐miR‐140‐3p was likely to be the most promising upstream regulation pathway of GPRIN1. Upexpression of LINC00894/MMP25‐AS1/SNHG1/LINC02298/MIR193BHG and downexpression of miR‐140‐3p were found relevant with poor outcomes of KIRP and LUAD. GPRIN1 expression was significantly correlated with tumor immune cell infiltration, immune cell biomarkers, and immune checkpoints.

Conclusions

The competitive endogenous (ceRNA) of miR‐140‐3p‐GPRIN1 axis and its upstream lncRNAs are closely related to KIRP and LUAD, and might affect the prognosis and therapeutic effect of KIRP and LUAD.

G protein regulated inducer of neurite outgrowth 1 is a potential marker for lung cancer prognosis

Lung cancer mortality remains high, and only approximately 15% of patients with non-small cell lung cancer survive for more than five years. The purpose of this research was to investigate the prognostic value and biological functions of G protein regulated inducer of neuritis outgrowth 1(GPRIN1) in lung cancer. We used the Kaplan-Meier method to analyze the correlation between GPRIN1 and overall survival, and performed Cox regression to determine whether GPRIN1 might be an independent predictive factor for lung adenocarcinoma prognosis. qRT-PCR and Western blot assays were conducted to detect GPRIN1 expression in lung cancer cells and normal control cells. To detect the functional effects of knockdown/overexpression of GPRIN1 on lung cancer cells, we performed CCK-8, colony formation and Transwell assays. Through the Kaplan-Meier method, we found that GPRIN1 expression correlated with overall survival and adverse prognosis, and Cox regression indicated that GPRIN1 is as an independent predictive factor for lung adenocarcinoma. Furthermore, the mRNA and protein expression levels of GPRIN1 in lung cancer cells were markedly higher than those in normal cells. Downregulation of GPRIN1significantly decreased cell viability, colony formation, the number of invasive and migrating cells, and levels of epithelial-mesenchymal transition-related proteins in A549 cells. Overexpression of GPRIN1showed the opposite effect in Calu-1 cells. Together, these results indicated that GPRIN1 facilitates lung cancer proliferation and migration, possibly by affecting the epithelial-mesenchymal transition of lung cancer cells, suggesting that GPRIN1may be used as an effective target for the treatment of lung cancer.