Emerging roles of a pivotal lncRNA SBF2-AS1 in cancers

Immunological processes of enhancers and suppressors of long non-coding RNAs associated with brain tumors and inflammation

Immunological processes, such as inflammation, can both cause tumor suppression and cancer progression. Moreover, deregulated levels of long non-coding RNA (lncRNA) expression in the brain may cause inflammation and lead to the growth of tumors. Like other biological processes, the immune system's role in cancer is complicated, varies, and can help or hurt the cancer's maintenance. According to research, inflammation and brain cancer are correlated via several signaling pathways. A variety of lncRNAs have recently been revealed to influence cancer by modulating inflammatory pathways. As a result, lncRNAs have the potential to influence carcinogenesis, tumor formation, or tumor suppression via an increase or decrease in inflammation functions. Although the study and targeting of lncRNAs have made great progress in the treatment of cancer, there are definitely limitations and challenges. Using new technologies like nanocarriers and cell-penetrating peptides (CPPs) to target treatments without hurting healthy body tissues has shown to be very effective. In this review article, we have collected significantly related lncRNAs and their inhibitory or stimulating roles in inflammation and brain cancer for the first time. However, there are limitations, such as side effects and damage to normal tissues. With the advancement of new targeting technologies, these lncRNAs may be candidates for the specific targeting therapy of brain cancers by limiting inflammation or stimulating the immune system against them in the future.

Long non-coding RNAs: controversial roles in drug resistance of solid tumors mediated by autophagy

Current genome-wide studies have indicated that a great number of long non-coding RNAs (lncRNAs) are transcribed from the human genome and appeared as crucial regulators in a variety of cellular processes. Many studies have displayed a significant function of lncRNAs in the regulation of autophagy. Autophagy is a macromolecular procedure in cells in which intracellular substrates and damaged organelles are broken down and recycled to relieve cell stress resulting from nutritional deprivation, irradiation, hypoxia, and cytotoxic agents. Autophagy can be a double-edged sword and play either a protective or a damaging role in cells depending on its activation status and other cellular situations, and its dysregulation is related to tumorigenesis in various solid tumors. Autophagy induced by various therapies has been shown as a unique mechanism of resistance to anti-cancer drugs. Growing evidence is showing the important role of lncRNAs in modulating drug resistance via the regulation of autophagy in a variety of cancers. The role of lncRNAs in drug resistance of cancers is controversial; they may promote or suppress drug resistance via either activation or inhibition of autophagy. Mechanisms by which lncRNAs regulate autophagy to affect drug resistance are different, mainly mediated by the negative regulation of micro RNAs. In this review, we summarize recent studies that investigated the role of lncRNAs/autophagy axis in drug resistance of different types of solid tumors.

LncRNA CASC9 enhances the stability of SOCS-1 by combining with FUS to alleviate sepsis-induced liver injury

BACKGROUND

Liver injury plays a major role in the development of sepsis. Liver damage after sepsis is an independent risk factor for multiple organ failure and death. Cancer susceptibility candidate 9 (CASC9) exerts a protective effect on sepsis-induced acute lung injury (ALI). However, the role and underlying mechanism haven't been fully evaluated.

METHODS

Animal and cell models of sepsis were established in vivo and in vitro experiments. The histological and apoptosis analyses of liver tissues were tested by hematoxylin-eosin (HE) staining and terminal dUTP nick end labeling (TUNEL) assay, respectively. Serum levels of inflammatory cytokines were detected via using an enzyme-linked immunosorbent assay (ELISA). The expressions of CASC9, suppressor of cytokine signaling (SOCS)-1, Bcl-2, Bax, Bad, and caspase3 were measured by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting. Cell counting kit-8 (CCK-8) and flow cytometry were applied to examine cell viability and apoptosis, respectively. RNA immunoprecipitation (RIP) and RNA-pull down assay were used to verify the binding relationships among CASC9, SOCS-1 and FUS.

RESULTS

CASC9 and SOCS-1 were lowly expressed in animal and cell models of sepsis liver injury. CASC9 or SOCS-1 overexpression could inhibit cell apoptosis upon lipopolysaccharide (LPS) induction. Meanwhile, the serum levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and IL-8 were reduced by CASC9 or SOCS-1 overexpression in LPS-induced LO2 cells. Mechanistically, CASC9 interacted with fused in sarcoma (FUS) to stabilize the mRNA of SOCS-1. SOCS-1 silencing antagonized the effects of CASC9 on improving sepsis liver injury.

CONCLUSION

CASC9 overexpression ameliorated the sepsis-induced liver injury, and the probable underlying mechanism may be that CASC9 stabilized the SOCS-1 mRNA by interacting with FUS.

SBF2-AS1 and TreRNA: novel lncRNA players in triple-negative breast cancer pathogenesis

BACKGROUND

Compared to other breast cancer subtypes, triple-negative breast cancer (TNBC) has always been challenging for clinicians due to its aggressive behavior and lack of a specific treatment. There is a confirmed association between invasive features of tumors and increased epithelial-mesenchymal transition (EMT) process, which is consistent with a higher rate of EMT in TNBC.

METHODS AND RESULTS

We investigated the expression of EMT-related genes, SNAI1 and MMP7, and EMT-related lncRNAs, treRNA and SBF2-AS1, in 50 TNBC tumors and 50 non-TNBC tumors to reveal more regulators and effectors involved in TNBC malignancy. In the present study, we showed the overexpression of all the studied genes and lncRNAs in TNBC tumors compared to non-TNBC samples. Moreover, a significant association was observed between MMP7 and treRNA expression levels and larger tumor size. A positive correlation between SNAI1 and lncRNA treRNA expression levels was also detected.

CONCLUSIONS

Due to the differential expression and the potential diagnostic power of the studied genes, SBF2-AS1 and treRNA can be proposed as new probable biomarkers and therapeutic targets in TNBC.

YBX1/lncRNA SBF2-AS1 interaction regulates proliferation and tamoxifen sensitivity via PI3K/AKT/MTOR signaling in breast cancer cells

BACKGROUND

Y-box binding protein 1 (YBX1) is a multifunctional oncoprotein that can interact with several long non-coding RNAs (lncRNAs) to regulate metastasis in malignancies including breast cancer (BC). In the present study, we demonstrated the association of YBX1 with oncogenic lncRNA SBF2-AS1 (SET-binding factor 2 antisense RNA 1) via PI3K/AKT/mTOR signaling to regulate BC cell proliferation. We further explored the involvement of the YBX1/SBF2-AS1/PI3K/AKT/mTOR axis in the restoration of tamoxifen (TAM) sensitivity.

METHODS AND RESULTS

YBX1-SBF2-AS1 association was predicted in silico and verified by RNA immunoprecipitation (RIP)-qPCR assay. Transfection experiments, Real-time RT PCR, Western blots, Phospho AKT/mTOR antibody array kit, and cell proliferation/apoptosis assays were employed to detect the YBX1/SBF2-AS1/ PI3K/AKT/mTOR axis and its effects upon TAM treatment in vitro. We identified that the YBX1 protein specifically binds to lncRNA SBF2-AS1. Our transfection experiments in MCF-7 and MDA-MB-468 cells with SBF2-AS1 silenced or overexpressed YBX1 plasmids, and their negative controls revealed that YBX1 regulates the expression of SBF2-AS1 by forming a positive feedback loop for its activation. We further demonstrated YBX1-SBF2-AS1 association exerts its effects on cell proliferation via PI3K/AKT/mTOR signaling pathway. Furthermore, we observed an increase in TAM sensitivity in BC cells after the knockdown of YBX1-SBF2-AS1 marked by decreased cell proliferation through disruption of the PI3K/AKT/mTOR axis.

CONCLUSION

Our study has identified a novel YBX1/SBF2-AS1/PI3K/AKT/mTOR regulatory axis which may serve as a potential target to improve the effectiveness and efficacy of TAM treatment in BC.

Clinical significance and immune landscape of cuproptosis-related lncRNAs in kidney renal clear cell carcinoma: a bioinformatical analysis

Background

Kidney renal clear cell carcinoma (KIRC) is considered an immunogenic tumor. Cuproptosis is a newly identified copper-induced regulated cell death that relies on mitochondria respiration. Long noncoding RNAs (lncRNAs) have emerged as significant players in tumorigenesis and metastasis. However, there is a huge knowledge gap on the prognostic role of cuproptosis-related lncRNAs in KIRC. And, the clinical value of them is still unknown. Here, we aimed to develop a cuproptosis-related lncRNA prognostic signature in KIRC.

Methods

The messenger RNA (mRNA)/lncRNA expression profiles and the clinical information including age, gender, tumor stage, grade, and overall survival (OS) were acquired from The Cancer Genome Atlas (TCGA) database. The included KIRC samples were further randomly assigned into training (n=258) or testing (n=257) data sets. We performed Pearson correlation analysis to identify the cuproptosis-related lncRNAs and then constructed the prognostic signature using Cox regression analysis and LASSO algorithm. Subsequently, Kaplan-Meier survival analysis, a nomogram, and receiver operating characteristic (ROC) curve were performed to assess the predictive performance of the signature. Moreover, the immune characteristics and drug sensitivity related to the signature were also explored.

Results

The signature comprised 7 cuproptosis-related lncRNAs. The patients with a low-risk score had superior OS compared with those with a high-risk score. The survival rates of the high- and low-risk groups were 44.96% and 83.72% (P<0.001). The area under the curve (AUC) value for 1-, 3-, 5-year survival rate reached 0.814, 0.762 and 0.825, respectively. In addition, a nomogram was also generated; the AUC was 0.785 for risk score, higher than that for age (0.593), gender (0.489), grade (0.679), and stage (0.721). The high-risk group had more enriched immune- and tumor-related genes. Patients with low-risk scores were more sensitive to immunotherapy and the small molecular drugs GSK1904529A, tipifarnib, BX-912, FR-180204, and GSK1070916. Meanwhile, the high-risk group tended to be more sensitive to pyrimethamine, MS-275, and CGP-60474.

Conclusions

Collectively, we constructed a cuproptosis-related lncRNA prognostic signature with a higher predictive accuracy compared to multiple clinicopathological parameters, which may provide vital guidance for therapeutic strategies in KIRC. Combination of more prognostic biomarkers may further improve the accuracy.

Inferring miRNA sponge modules across major neuropsychiatric disorders

The role of non-coding RNAs in neuropsychiatric disorders (NPDs) is an emerging field of study. The long non-coding RNAs (lncRNAs) are shown to sponge the microRNAs (miRNAs) from interacting with their target mRNAs. Investigating the sponge activity of lncRNAs in NPDs will provide further insights into biological mechanisms and help identify disease biomarkers. In this study, a large-scale inference of the lncRNA-related miRNA sponge network of pan-neuropsychiatric disorders, including autism spectrum disorder (ASD), schizophrenia (SCZ), and bipolar disorder (BD), was carried out using brain transcriptomic (RNA-Seq) data. The candidate miRNA sponge modules were identified based on the co-expression pattern of non-coding RNAs, sharing of miRNA binding sites, and sensitivity canonical correlation. miRNA sponge modules are associated with chemical synaptic transmission, nervous system development, metabolism, immune system response, ribosomes, and pathways in cancer. The identified modules showed similar and distinct gene expression patterns depending on the neuropsychiatric condition. The preservation of miRNA sponge modules was shown in the independent brain and blood-transcriptomic datasets of NPDs. We also identified miRNA sponging lncRNAs that may be potential diagnostic biomarkers for NPDs. Our study provides a comprehensive resource on miRNA sponging in NPDs.

Long non-coding RNAs and exosomal lncRNAs: Potential functions in lung cancer progression, drug resistance and tumor microenvironment remodeling

Among the different kinds of tumors threatening human life, lung cancer is one that is commonly observed in both males and females. The aggressive behavior of lung cancer and interactions occurring in tumor microenvironment enhances the malignancy of this tumor. The lung tumor cells have demonstrated capacity in developing chemo- and radio-resistance. LncRNAs are a category of non-coding RNAs that do not encode proteins, but their aberrant expression is responsible for tumor development, especially lung cancer. In the present review, we focus on both lncRNAs and exosomal lncRNAs in lung cancer, and their ability in regulating proliferation and metastasis. Cell cycle progression and molecular mechanisms related to lung cancer metastasis such as EMT and MMPs are regulated by lncRNAs. LncRNAs interact with miRNAs, STAT, Wnt, EZH2, PTEN and PI3K/Akt signaling pathways to affect progression of lung cancer cells. LncRNAs demonstrate both tumor-suppressor and tumor-promoting functions in lung cancer. They can be considered as biomarkers in lung cancer and especially exosomal lncRNAs present in body fluids are potential tools for minimally invasive diagnosis. Furthermore, we discuss regulation of lncRNAs by anti-cancer drugs and genetic tools as well as the role of these factors in therapy response of lung cancer cells.