Knockdown of long noncoding RNA DLEU1 suppresses the progression of renal cell carcinoma by downregulating the Akt pathway

Predicting prognosis, immunotherapy and distinguishing cold and hot tumors in clear cell renal cell carcinoma based on anoikis-related lncRNAs

Background

Clear cell renal cell carcinoma (ccRCC) is the most frequently occurring malignant tumor within the kidney cancer subtype. It has low sensitivity to traditional radiotherapy and chemotherapy, the optimal treatment for localized ccRCC has been surgical resection, but even with complete resection the tumor will be eventually developed into metastatic disease in up to 40% of localized ccRCC. For this reason, it is crucial to find early diagnostic and treatment markers for ccRCC.

Methods

We obtained anoikis-related genes (ANRGs) integrated from Genecards and Harmonizome dataset. The anoikis-related risk model was constructed based on 12 anoikis-related lncRNAs (ARlncRNAs) and verified by principal component analysis (PCA), Receiver operating characteristic (ROC) curves, and T-distributed stochastic neighbor embedding (t-SNE), and the role of the risk score in ccRCC immune cell infiltration, immune checkpoint expression levels, and drug sensitivity was evaluated by various algorithms. Additionally, we divided patients based on ARlncRNAs into cold and hot tumor clusters using the ConsensusClusterPlus (CC) package.

Results

The AUC of risk score was the highest among various factors, including age, gender, and stage, indicating that the model we built to predict survival was more accurate than the other clinical features. There was greater sensitivity to targeted drugs like Axitinib, Pazopanib, and Sunitinib in the high-risk group, as well as immunotherapy drugs. This shows that the risk-scoring model can accurately identify candidates for ccRCC immunotherapy and targeted therapy. Furthermore, our results suggest that cluster 1 is equivalent to hot tumors with enhanced sensitivity to immunotherapy drugs.

Conclusion

Collectively, we developed a risk score model based on 12 prognostic lncRNAs, expected to become a new tool for evaluating the prognosis of patients with ccRCC, providing different immunotherapy strategies by screening for hot and cold tumors.

The Role of Long Non-Coding RNAs (lncRNAs) in Female Oriented Cancers

Recent advances in molecular biology have discovered the mysterious role of long non-coding RNAs (lncRNAs) as potential biomarkers for cancer diagnosis and targets for advanced cancer therapy. Studies have shown that lncRNAs take part in the incidence and development of cancers in humans. However, previously they were considered as mere RNA noise or transcription byproducts lacking any biological function. In this article, we present a summary of the progress on ascertaining the biological functions of five lncRNAs (HOTAIR, NEAT1, H19, MALAT1, and MEG3) in female-oriented cancers, including breast and gynecological cancers, with the perspective of carcinogenesis, cancer proliferation, and metastasis. We provide the current state of knowledge from the past five years of the literature to discuss the clinical importance of such lncRNAs as therapeutic targets or early diagnostic biomarkers. We reviewed the consequences, either oncogenic or tumor-suppressing features, of their aberrant expression in female-oriented cancers. We tried to explain the established mechanism by which they regulate cancer proliferation and metastasis by competing with miRNAs and other mechanisms involved via regulating genes and signaling pathways. In addition, we revealed the association between stated lncRNAs and chemo-resistance or radio-resistance and their potential clinical applications and future perspectives.

Overexpression of lncRNA DLEU1 in Gastric Cancer Tissues Compared to Adjacent Non-Tumor Tissues

PURPOSE

Gastric cancer (GC) is caused by environmental factors and genetic changes of protein-coding- and non-coding sequences, which entail short non-coding RNAs (microRNAs) and long non-coding RNAs (lncRNAs). DLEU1 (deleted in lymphocytic leukemia 1), as an effective lncRNA located on chromosome 14.3q 13, modulates the nuclear factor-kB (NF-kB) signaling pathway. This gene usually plays an oncogenic role in the tumorigenesis of multiple types of cancer. The present study examined the expression level of DLEU1 and its association with clinical-pathological characteristics in GC.

METHODS

Total RNA of 100 specimens was extracted by TRIzol reagent. After cDNA synthesis, qRT-PCR analysis was performed to measure the expression level of the DLEU1 gene and the obtained data were analyzed by SPSS 16.0.

RESULTS

The relative expression level of DLEU1 significantly increased in tumor specimens compared to the normal tumor margin specimens. The biomarker index of lncRNA DLEU1 was 0.7 in tumor tissues. The observed high expression level of DLEU1 was pertinent to the pathological progressive TNM stage, lymph node metastasis, differentiation degree, patient's age and lifestyle, and Helicobacter pylori infection in GC patients.

CONCLUSION

The obtained findings suggested that DLEU1 acts as an oncogene in GC and might be a new target for gene therapy of GC.

LncRNAs in the Regulation of Genes and Signaling Pathways through miRNA-Mediated and Other Mechanisms in Clear Cell Renal Cell Carcinoma

The fundamental novelty in the pathogenesis of renal cell carcinoma (RCC) was discovered as a result of the recent identification of the role of long non-coding RNAs (lncRNAs). Here, we discuss several mechanisms for the dysregulation of the expression of protein-coding genes initiated by lncRNAs in the most common and aggressive type of kidney cancer-clear cell RCC (ccRCC). A model of competitive endogenous RNA (ceRNA) is considered, in which lncRNA acts on genes through the lncRNA/miRNA/mRNA axis. For the most studied oncogenic lncRNAs, such as HOTAIR, MALAT1, and TUG1, several regulatory axes were identified in ccRCC, demonstrating a number of sites for various miRNAs. Interestingly, the LINC00973/miR-7109/Siglec-15 axis represents a novel agent that can suppress the immune response in patients with ccRCC, serving as a valuable target in addition to the PD1/PD-L1 pathway. Other mechanisms of action of lncRNAs in ccRCC, involving direct binding with proteins, mRNAs, and genes/DNA, are also considered. Our review briefly highlights methods by which various mechanisms of action of lncRNAs were verified. We pay special attention to protein targets and signaling pathways with which lncRNAs are associated in ccRCC. Thus, these new data on the different mechanisms of lncRNA functioning provide a novel basis for understanding the pathogenesis of ccRCC and the identification of new prognostic markers and targets for therapy.

DLEU1 promotes oral squamous cell carcinoma progression by activating interferon-stimulated genes

Long noncoding RNAs (lncRNAs) are deeply involved in cancer development. We previously reported that DLEU1 (deleted in lymphocytic leukemia 1) is one of the lncRNAs overexpressed in oral squamous cell carcinoma (OSCC) cells, where it exhibits oncogenic activity. In the present study, we further clarified the molecular function of DLEU1 in the pathogenesis of OSCC. Chromatin immunoprecipitation-sequencing (ChIP-seq) analysis revealed that DLEU1 knockdown induced significant changes in the levels of histone H3 lysine 4 trimethylation (H3K4me3) and H3K27 acetylation (H3K27ac) in OSCC cells. Notably, DLEU1 knockdown suppressed levels of H3K4me3/ H3K27ac and expression of a number of interferon-stimulated genes (ISGs), including IFIT1, IFI6 and OAS1, while ectopic DLEU1 expression activated these genes. Western blot analysis and reporter assays suggested that DLEU1 upregulates ISGs through activation of JAK-STAT signaling in OSCC cells. Moreover, IFITM1, one of the ISGs induced by DLUE1, was frequently overexpressed in primary OSCC tumors, and its knockdown inhibited OSCC cell proliferation, migration and invasion. These findings suggest that DLEU1 exerts its oncogenic effects, at least in part, through activation of a series ISGs in OSCC cells.

Knockdown lncRNA DLEU1 Inhibits Gliomas Progression and Promotes Temozolomide Chemosensitivity by Regulating Autophagy

Gliomas are the most fatal malignant cerebral tumors. Temozolomide (TMZ), as the primary chemotherapy drug, has been widely used in clinics. However, resistance of TMZ still remains to poor defined. LncRNAs have been reported to play crucial roles in progression of various cancers and resistance of multiple drugs. However, the biological function and underlying mechanisms of most lncRNAs in glioma still remains unclear. Based on the TCGA database, a total of 94 differentially expressed lncRNAs, including 16 up-regulated genes and 78 downregulated genes were identified between gliomas and normal brain tissues. Subsequently, lncRNA DLEU1, HOTAIR, and LOC00132111 were tested to be significantly related to overall survival (OS) between high- and low-expression groups. Additionally, we verified that lncRNA DLEU1 was high expressed in 108 gliomas, compared with 19 normal brain tissues. And high expression of lncRNA DLEU1 predicted a poor prognosis (HR = 1.703, 95%CI: 1.133–2.917, p-value = 0.0159). Moreover, functional assays revealed that knockdown of lncRNA DLEU1 could suppress the proliferation by inducing cell cycle arrest at G1 phase and reducing the S phase by down-regulating the CyclinD1 and p-AKT, as the well as migration and invasion by inhibiting the epithelial–mesenchymal transition (EMT) markers, such as ZEB1, N-cadherin, β-catenin and snail in glioma cells. Furthermore, silencing lncRNA DLEU1 suppressed TMZ-activated autophagy via regulating the expression of P62 and LC3, and promoted sensitivity of glioma cells to TMZ by triggering apoptosis. Conclusively, our study indicated that lncRNA DLEU1 might perform as a prognostic potential target and underlying therapeutic target for sensitivity of glioma to TMZ.

Long non‑coding RNA PLK1S1 was associated with renal cell carcinoma progression by interacting with microRNA‑653 and altering C‑X‑C chemokine receptor 5 expression

Renal cell carcinoma (RCC) is the most common type of renal cancer. Long non-coding RNA (lncRNA) has been reported to play a vital role in the development and progression of various types of cancer type. However, the underlying molecular mechanisms of PLK1S1 in regulating RCC progression remain unclear. In the present study, PLK1S1 was upregulated in RCC tissues and cells, and PLK1S1 expression was also significantly elevated in stage IV RCC tissues. Kaplan-Meier analysis showed that patients with high PLK1S1 expression had a shorter overall survival time compared with those with low PLK1S1 expression. Moreover, bioinformatics analysis and luciferase reporter assay demonstrated that PLK1S1 inhibited microRNA (miR)-653 expression by direct interaction. Functional analyses demonstrated that a miR-653 inhibitor promoted short hairpin PLK1S1-attenuated cell proliferation, invasion and sorafenib resistance of RCC cells. In addition, C-X-C motif chemokine receptors 5 (CXCR5) was identified as an effector of PLK1S1/miR-653-mediated tumorigenesis and drug resistance in RCC cells. Lastly, xenograft experiments demonstrated that PLK1S1 knockdown inhibited tumor growth in vivo. Reverse transcription-quantitative PCR and western blot analysis revealed that PLK1S1 knockdown upregulated the expression level of miR-653, whilst downregulating the expression level of CXCR5. In conclusion, the present study revealed that PLK1S1 promoted tumor progression and sorafenib resistance in RCC through regulation of the miR-653/CXCR5 axis, which may offer a novel treatment strategy for patients with RCC.