Long Non-coding RNA JHDM1D-AS1 Interacts with DHX15 Protein to Enhance Non-Small-Cell Lung Cancer Growth and Metastasis

KDM7A-DT induces genotoxic stress, tumorigenesis, and progression of p53 missense mutation-associated invasive breast cancer

Stress-induced promoter-associated and antisense lncRNAs (si-paancRNAs) originate from a reservoir of oxidative stress (OS)-specific promoters via RNAPII pausing-mediated divergent antisense transcription. Several studies have shown that the KDM7A divergent transcript gene (KDM7A-DT), which encodes a si-paancRNA, is overexpressed in some cancer types. However, the mechanisms of this overexpression and its corresponding roles in oncogenesis and cancer progression are poorly understood. We found that KDM7A-DT expression is correlated with highly aggressive cancer types and specific inherently determined subtypes (such as ductal invasive breast carcinoma (BRCA) basal subtype). Its regulation is determined by missense TP53 mutations in a subtype-specific context. KDM7A-DT transcribes several intermediate-sized ncRNAs and a full-length transcript, exhibiting distinct expression and localization patterns. Overexpression of KDM7A-DT upregulates TP53 protein expression and H2AX phosphorylation in nonmalignant fibroblasts, while in semi-transformed fibroblasts, OS superinduces KDM7A-DT expression in a TP53-dependent manner. KDM7A-DT knockdown and gene expression profiling in TP53-missense mutated luminal A BRCA variant, where it is abundantly expressed, indicate its significant role in cancer pathways. Endogenous over-expression of KDM7A-DT inhibits DNA damage response/repair (DDR/R) via the TP53BP1-mediated pathway, reducing apoptosis and promoting G2/M checkpoint arrest. Higher KDM7A-DT expression in BRCA is associated with KDM7A-DT locus gain/amplification, higher histologic grade, aneuploidy, hypoxia, immune modulation scores, and activation of the c-myc pathway. Higher KDM7A-DT expression is associated with relatively poor survival outcomes in patients with luminal A or Basal subtypes. In contrast, it is associated with favorable outcomes in patients with HER2+ER- or luminal B subtypes. KDM7A-DT levels are coregulated with critical transcripts and proteins aberrantly expressed in BRCA, including those involved in DNA repair via non-homologous end joining and epithelial-to-mesenchymal transition pathway. In summary, KDM7A-DT and its si-lncRNA exhibit several intrinsic biological and clinical characteristics that suggest important roles in invasive BRCA and its subtypes. KDM7A-DT-defined mRNA and protein subnetworks offer resources for identifying clinically relevant RNA-based signatures and prospective targets for therapeutic intervention.

Fusobacterium nucleatum promotes tumor progression in KRAS p.G12D-mutant colorectal cancer by binding to DHX15

Fusobacterium nucleatum (F. nucleatum) promotes intestinal tumor growth and its relative abundance varies greatly among patients with CRC, suggesting the presence of unknown, individual-specific effectors in F. nucleatum-dependent carcinogenesis. Here, we identify that F. nucleatum is enriched preferentially in KRAS p.G12D mutant CRC tumor tissues and contributes to colorectal tumorigenesis in Villin-Cre/KrasG12D+/- mice. Additionally, Parabacteroides distasonis (P. distasonis) competes with F. nucleatum in the G12D mouse model and human CRC tissues with the KRAS mutation. Orally gavaged P. distasonis in mice alleviates the F. nucleatum-dependent CRC progression. F. nucleatum invades intestinal epithelial cells and binds to DHX15, a protein of RNA helicase family expressed on CRC tumor cells, mechanistically involving ERK/STAT3 signaling. Knock out of Dhx15 in Villin-Cre/KrasG12D+/- mice attenuates the CRC phenotype. These findings reveal that the oncogenic effect of F. nucleatum depends on somatic genetics and gut microbial ecology and indicate that personalized modulation of the gut microbiota may provide a more targeted strategy for CRC treatment.

LncRNA JHDM1D-AS1 promotes osteogenic differentiation of periodontal ligament cells by targeting miR-532-5p to activate IGF1R signaling

OBJECTIVE

The aim of this study was to explore the mechanism underlying periodontal ligament cells (PDLCs) osteogenic differentiation.

BACKGROUND

Periodontitis causes damage to tooth-supporting apparatus and eventually leads to tooth loss. PDLCs hold great promise in periodontal regeneration due to their osteogenic features.

METHODS

The expression of osteogenic markers, lncRNA JHDM1D-AS1, miR-532-5p and IGF1R was examined. For osteogenic differentiation, primary human PDLCs (hPDLCs) were cultured in an osteogenic medium, and it was assessed by ALP activity and Alizarin Red staining. The interaction between JHDM1D-AS1, miR-532-5p and IGF1R was analyzed via dual luciferase, RIP and RNA pull-down assays.

RESULTS

JHDM1D-AS1 was up-regulated during osteogenic differentiation and its silencing inhibited hPDLC osteogenic differentiation. JHDM1D-AS1 worked as a miR-532-5p sponge in hPDLCs. miR-532-5p directly targeted IGF1R to suppress its expression, and miR-532-5p knockdown facilitated osteogenic differentiation of hPDLCs. Overexpression of IGF1R promoted osteogenic differentiation of hPDLCs via activating Notch/HES1 signaling in hPDLCs.

CONCLUSION

JHDM1D-AS1 promotes osteogenic differentiation of hPDLCs via sponging miR-532-5p to facilitate IGF1R expression and activate Notch/HES1 signaling.

Comprehensive analysis the prognostic and immune characteristics of mitochondrial transport-related gene SFXN1 in lung adenocarcinoma

BACKGROUND

Mitochondria, which serve as the fundamental organelle for cellular energy and metabolism, are closely linked to the growth and survival of cancer cells. This study aims to identify and assess Sideroflexin1 (SFXN1), an unprecedented mitochondrial gene, as a potential prognostic biomarker for lung adenocarcinoma (LUAD).

METHODS

The mRNA and protein levels of SFXN1 were investigated based on the Cancer Genome Atlas (TCGA) LUAD dataset, and then validated by real-time quantitative PCR, Western Blotting and immunohistochemistry from our clinical samples. The clinical correlation and prognostic value were evaluated by the TCGA cohort and verified via our clinical dataset (n = 90). The somatic mutation, drug sensitivity data, immune cell infiltration and single-cell RNA sequencing data of SFXN1 were analyzed through public databases.

RESULTS

SFXN1 was markedly upregulated at both mRNA and protein levels in LUAD, and high expression of SFXN1 were correlated with larger tumor size, positive lymph node metastasis, and advanced clinical stage. Furthermore, SFXN1 upregulation was significantly associated with poor clinical prognosis. SFXN1 co-expressed genes were also analyzed, which were mainly involved in the cell cycle, central carbon metabolism, DNA repair, and the HIF-1α signaling pathway. Additionally, SFXN1 expression correlated with the expression of multiple immunomodulators, which act to regulate the tumor immune microenvironment. Results also demonstrated an association between SFXN1 expression and increased immune cell infiltration, such as activated CD8 + T cells, natural killer cells (NKs), activated dendritic cells (DCs), and macrophages. LUAD patients with high SFXN1 expression exhibited heightened sensitivity to multiple chemotherapies and targeted drugs and predicted a poor response to immunotherapy. SFXN1 represented an independent prognostic marker for LUAD patients with an improved prognostic value for overall survival when combined with clinical stage information.

CONCLUSIONS

SFXN1 is frequently upregulated in LUAD and has a significant impact on the tumor immune environment. Our study uncovers the potential of SFXN1 as a prognostic biomarker and as a novel target for intervention in LUAD.

SOX9 promotes the invasion and migration of lung adenocarcinoma cells by activating the RAP1 signaling pathway

OBJECTIVE

SOX9 has been shown to be related to the metastasis of various cancers. Recently, it has been reported that SOX9 plays a regulatory role in lung adenocarcinoma (LUAD) cell metastasis, but the specific mechanism remains to be explored. Therefore, the objective of this study was to observe the effect and mechanism of SOX9 on the invasion and migration of LUAD cells.

METHODS

RT-qPCR was applied to observe the expression of SOX9 and RAP1 in tumor tissues and corresponding normal lung tissues collected from LUAD patients. Co-immunoprecipitation and Pearson correlation to analyze the expression correlation of SOX9 with RAP1. To observe the role of SOX9, the invasion and migration levels of LUAD A549 cells in each group were observed by Transwell invasion assay and Scratch migration assay after knocking down or overexpressing SOX9. Besides, the expression levels of RAP1 pathway-related proteins (RAP1, RAP1GAP and RasGRP33) were observed by RT-qCPR or western blot. Subsequently, RAP1 was overexpressed and SOX9 was knocked down in A549 cells, and then the cell invasion/migration level and RAP1 pathway activity were assessed.

RESULTS

The expression levels of SOX9 and RAP1 in tumor tissues and A549 cells of LUAD patients were significantly increased and positively correlated. Overexpression of SOX9 or RAP1 alone in A549 cells enhanced the invasion and migration ability of cells, as well as up-regulated the expression levels of RAP1, RAP1GAP and RasGRP33. However, knocking down SOX9 decreased cell invasion and migration levels and weakened the activity of RAP1 pathway. Notably, overexpressing RAP1 while knocking down SOX9 significantly activated RAP1 pathway and promoted cell invasion and migration.

CONCLUSION

Overexpression of SOX9 in LUAD can significantly activate the RAP1 signaling pathway and promote cell invasion and migration.

Decoding the role of long non-coding RNAs in periodontitis: A comprehensive review

Periodontitis is an inflammatory disease characterized by the pathological loss of alveolar bone and the adjacent periodontal ligament. It is considered a disease that imposes a substantial health burden, with an incidence rate of 20-50%. The etiology of periodontitis is multifactorial, with genetic factors accounting for approximately half of severe cases. Studies have revealed that long non-coding RNAs (lncRNAs) play a pivotal role in periodontitis pathogenesis. Accumulating evidence suggests that lncRNAs have distinct regulatory mechanisms, enabling them to control numerous vital processes in periodontal cells, including osteogenic differentiation, inflammation, proliferation, apoptosis, and autophagy. In this review, we summarize the diverse roles of lncRNAs in the pathogenesis of periodontitis, shedding light on the underlying mechanisms of disease development. By highlighting the potential of lncRNAs as biomarkers and therapeutic targets, this review offers a new perspective on the diagnosis and treatment of periodontitis, paving the way for further investigation into the field of lncRNA-based therapeutics.

Relationship between DHX15 expression and survival in colorectal cancer

OBJECTIVE

to explore the relationship between the expression of DEAH-box RNA helicase 15 (DHX15) in colorectal cancer (CRC), its clinical pathological features and survival.

METHOD

DHX15 expression data with clinical pathological features from the Cancer Gene Atlas (TCGA) and the Clinical Proteomic Tumor Analysis Consortium (CPTAC) were statistically analyzed for the association between DHX15 expression and overall survival in CRC. The expression of DHX15 was performed by immunohistochemical staining (IHC) using tumor and the adjacent normal tissue, mounted in tissue microarrays. The significance of DHX15 expression to predict survival and prognosis of CRC were analyzed using the Kaplan-Meier method, univariate and multivariate Cox regression analysis.

RESULTS

low expression of DHX15 mRNA and DHX15 protein in CRC were both negative factors for survival. Overall survival of patients with low-expression of DHX15 was significantly lower (χ2 = 8.452, p = 0.004) by Kaplan-Meier evaluation. Low expression of DHX15 in CRC tissues correlated with distal lymph node metastasis (χ² = 7.120, p = 0.008), TNM stage (χ² = 3.935, p = 0.047) and disease recurrence (χ² = 9.524, p = 0.002) in CRC. Low expression of DHX15 (HR = 4.012, 95 % CI: 1.462-11.013, p = 0.007), late TNM stage (HR = 0.067, 95 % CI: 0.029-0.156, p < 0.001) and recurrence (HR = 0.008, 95 % CI: 0.002-0.034, p < 0.001) were risk factors related to the prognosis of CRC patients by univariate Cox regression analysis.

CONCLUSION

our findings reveal a key role for DHX15 in the progress of CRC metastasis and recurrence. DHX15 may be a potential biomarker for CRC targeted therapy.

RNF182 induces p65 ubiquitination to affect PDL1 transcription and suppress immune evasion in lung adenocarcinoma

BACKGROUND

The RING finger (RNF) proteins are a large group of ubiquitin ligases whose aberrant expression is often associated with disease progression. This study examines the function of RNF protein 182 (RNF182) in lung adenocarcinoma (LUAD) cells and its impact on p65 and programmed death ligand 1 (PDL1) regulation.

METHODS

Expression of RNF182, p65, and PDL1 in LUAD tissues and cells was measured using immunohistochemistry, reverse transcription quantitative polymerase chain reaction (RT-qPCR), and/or western blot (WB) assays. LUAD cells were induced to overexpress RNF182 and p65, followed by cell counting kit-8, colony formation, Transwell, and flow cytometry assays to evaluate the cells' malignant phenotype. Coimmunoprecipitation and WB assays were used to verify RNF182's effect on p65 ubiquitination. Chromatin immunoprecipitation-qPCR and luciferase assays were used to analyze p65's transcriptional regulation of PDL1. Coculture of LUAD with CD8⁺ cytotoxic T cells was performed to detect lactate dehydrogenase release and interferon-γ and interleukin-2 concentrations. LUAD cells were implanted in mice to analyze tumorigenicity.

RESULTS

RNF182 was poorly expressed, while p65 and PDL1 were highly expressed in LUAD tissues and cells. RNF182 overexpression suppressed the malignant properties of LUAD cells, and it promoted p65 ubiquitination and protein degradation. p65 activated PDL1 transcription. Overexpression of RNF182 suppressed the PDL1 expression, increased the cytotoxicity in LUAD cells cocultured with CD8⁺ T cells, and suppressed the tumorigenesis of cancer cells in vivo. However, these tumor-suppressive effects of RNF182 on LUAD cells were blocked by p65 restoration.

CONCLUSION

This research demonstrates that RNF182 induces p65 ubiquitination to suppress PDL1 transcription and immunosuppression in LUAD.

High Expression of COA6 Is Related to Unfavorable Prognosis and Enhanced Oxidative Phosphorylation in Lung Adenocarcinoma

Mitochondrial metabolism plays an important role in the occurrence and development of cancers. Cytochrome C oxidase assembly factor six (COA6) is essential in mitochondrial metabolism. However, the role of COA6 in lung adenocarcinoma (LUAD) remains unknown. Here we report that the expression of COA6 mRNA and protein were upregulated in LUAD tissues compared with lung normal tissues. We found that COA6 had high sensitivity and specificity to distinguish LUAD tissues from normal lung tissues shown by a receiver operating characteristic (ROC) curve. In addition, our univariate and multivariate Cox regression analysis indicated that COA6 was an independent unfavorable prognostic factor for LUAD patients. Furthermore, our survival analysis and nomogram showed that a high expression of COA6 mRNA was related to the short overall survival (OS) of LUAD patients. Notably, our weighted correlation network analysis (WGCNA) and functional enrichment analysis revealed that COA6 may participate in the development of LUAD by affecting mitochondrial oxidative phosphorylation (OXPHOS). Importantly, we demonstrated that depletion of COA6 could decrease the mitochondrial membrane potential (MMP), nicotinamide adenine dinucleotide (NAD) + hydrogen (H) (NADH), and adenosine triphosphate (ATP) production in LUAD cells (A549 and H1975), hence inhibiting the proliferation of these cells in vitro. Together, our study strongly suggests that COA6 is significantly associated with the prognosis and OXPHOS in LUAD. Hence, COA6 is highly likely a novel prognostic biomarker and therapeutic target of LUAD.

LncRNA JHDM1D-AS1 Is a Key Biomarker for Progression and Modulation of Gemcitabine Sensitivity in Bladder Cancer Cells

Long non-coding RNAs are frequently found to be dysregulated and are linked to carcinogenesis, aggressiveness, and chemoresistance in a variety of tumors. As expression levels of the JHDM1D gene and lncRNA JHDM1D-AS1 are altered in bladder tumors, we sought to use their combined expression to distinguish between low-and high-grade bladder tumors by RTq-PCR. In addition, we evaluated the functional role of JHDM1D-AS1 and its association with the modulation of gemcitabine sensitivity in high-grade bladder-tumor cells. J82 and UM-UC-3 cells were treated with siRNA-JHDM1D-AS1 and/or three concentrations of gemcitabine (0.39, 0.78, and 1.56 µM), and then submitted to cytotoxicity testing (XTT), clonogenic survival, cell cycle progression, cell morphology, and cell migration assays. When JHDM1D and JHDM1D-AS1 expression levels were used in combination, our findings indicated favorable prognostic value. Furthermore, the combined treatment resulted in greater cytotoxicity, a decrease in clone formation, G0/G1 cell cycle arrest, morphological alterations, and a reduction in cell migration capacity in both lineages compared to the treatments alone. Thus, silencing of JHDM1D-AS1 reduced the growth and proliferation of high-grade bladder-tumor cells and increased their sensitivity to gemcitabine treatment. In addition, the expression of JHDM1D/JHDM1D-AS1 indicated potential prognostic value in the progression of bladder tumors.

Familial 4p Interstitial Deletion Provides New Insights and Candidate Genes Underlying This Rare Condition

Chromosome 4p deletions can lead to two distinct phenotypic outcomes: Wolf-–Hirschhorn syndrome (a terminal deletion at 4p16.3) and less frequently reported proximal interstitial deletions (4p11-p16). Proximal 4p interstitial deletions can result in mild to moderate intellectual disability, facial dysmorphisms, and a tall thin body habitus. To date, only 35 cases of proximal 4p interstitial deletions have been reported, and only two of these cases have been familial. The critical region for this syndrome has been narrowed down to 4p15.33-15.2, but the underlying causative genes remain unclear. In this study, we report the case of a 3-year-old female with failure to thrive, developmental and motor delays, and morphological features. The mother also had a 4p15.2-p14 deletion, and the proband was found to have a 13.4-Mb 4p15.2-p14 deletion by chromosome microarray analysis. The deleted region encompasses 16 genes, five of which have a high likelihood of contributing to the phenotype: PPARGC1A, DHX15, RBPJ, STIM2, and PCDH7. These findings suggest that multiple genes are involved in this rare proximal 4p interstitial deletion syndrome. This case highlights the need for healthcare providers to be aware of proximal 4p interstitial deletions and the potential phenotypic manifestations.

JHDM1D-AS1-driven inhibition of miR-940 releases ARTN expression to induce breast carcinogenesis

INTRODUCTION

As ceRNA network of long non-coding RNA (lncRNA)-microRNA (miR)-messenger RNAs (mRNA) can be predicted on the basis of bioinformatics tools, we are now one step closer to deeper understanding carcinogenic mechanisms. In this study, we clarified the mechanistic understanding of JHDM1D-AS1-miR-940-ARTN ceRNA network in the development of breast cancer (BC).

MATERIALS AND METHODS

The lncRNA-miRNA-mRNA interaction of interest was predicted by in silico analysis and identified by conducting RNA immunoprecipitation, RNA pull-down and luciferase assays. The expression patterns of JHDM1D-AS1, miR-940 and ARTN in BC cells were altered by lentivirus infection and plasmid transfection for functional assays on the biological properties of BC cells. Finally, the tumorigenic and metastatic abilities of BC cells were assessed in vivo.

RESULTS

JHDM1D-AS1 was highly expressed, while miR-940 was poorly expressed in BC tissues and cells. JHDM1D-AS1 could competitively bind to miR-940, whereby promoting the malignant behaviors of BC cells. Furthermore, ARTN was identified as a target gene of miR-940. Through targeting ARTN, miR-940 exerted a tumor-suppressive role. In vivo experiments further confirmed that JHDM1D-AS1 enhanced the tumorigenesis and metastasis through up-regulation of ARTN.

CONCLUSIONS

Taken together, our study demonstrated the involvement of ceRNA network JHDM1D-AS1-miR-940-ARTN in the progression of BC, which highlighted promising therapeutic targets for BC treatment.

Clear Cell Carcinoma Arising in Low-Grade Mullerian Adenosarcoma: First Reported Case with Insight into Molecular Profile

Uterine adenosarcoma (AS) is a rare biphasic neoplasm composed of a malignant, usually low-grade stromal component and benign epithelial component, usually endometrioid. Pathogenesis is unknown; some cases are undoubtably associated with tamoxifen use. Endometrial clear cell carcinoma (CCC) is an aggressive subtype of endometrial cancer, accounting for less than 10% of all uterine carcinomas. The etiology is unknown but can rarely be associated with Lynch syndrome and tamoxifen administration. The development of a composite neoplasm consisting of adenocarcinoma in AS is extremely rare. Endometrioid carcinoma typically represents the epithelial component of the composite tumor. Here we present the very first case of composite tumor, namely, AS with CCC in which next-generation sequencing was performed. Patient was an 85-year-old woman treated with tamoxifen for 5 years. To better understand the pathobiology of two tumors, a targeted genomic analysis of both components was performed. We found seven identical somatic variants in the samples of both tumors, indicating that the tumors have a high probability of having the same origin. Dual amplification of CDK4 and MDM2 was the most likely primary cause of tumor formation, but also one driver variant in the DHX15 gene that was present in both tumor components, suggesting that DHX15 may play an important role in the initiation and development of sarcoma and carcinoma. The patient is followed by regular clinical controls and is alive without signs of disease recurrence 18 months after surgery.

Positive feedback regulation of lncRNA TPT1-AS1 and ITGB3 promotes cell growth and metastasis in pancreatic cancer

Emerging evidence has indicated that long noncoding RNAs (lncRNAs) are potential biomarkers and play crucial roles in cancer development. However, the functions and underlying mechanisms of lncRNA TPT1-AS1 in pancreatic ductal adenocarcinoma (PDAC) remain elusive. RNAseq data of PDAC tissues and normal tissues were analyzed, and lncRNAs which were associated with PDAC prognosis were identified. The clinical relevance of TPT1-AS1 for PDAC patients was explored, and the effects of TPT1-AS1 in PDAC progression were investigated in vitro and in vivo. LncRNA TPT1-AS1 was highly expressed in PDAC, and high TPT1-AS1 levels predicted a poor prognosis. Moreover, functional experiments revealed that TPT1-AS1 promoted pancreatic cancer cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT) process in vitro and in vivo. Mechanistically, TPT1-AS1 functioned as an endogenous sponge for miR-30a-5p, which increased integrin β3 (ITGB3) level in pancreatic cancer cells. Conversely, our data revealed that ITGB3 could activate the transcription factor signal transducer and activator of transcription 3 (STAT3), which in turn bound directly to the TPT1-AS1 promoter and affected the expression of TPT1-AS1, thus forming a positive feedback loop with TPT1-AS1. Taken together, our results uncovered a reciprocal loop of TPT1-AS1 and ITGB3 which contributed to pancreatic cancer growth and development, and indicated that TPT1-AS1 might serve as a novel potential diagnostic biomarker and therapeutic target for PDAC patients.

The Long Non-Coding Antisense RNA JHDM1D-AS1 Regulates Inflammatory Responses in Human Monocytes

Monocytes are key players in innate immunity, with their ability to regulate inflammatory responses and combat invading pathogens. There is a growing body of evidence indicating that long non-coding RNA (lncRNA) participate in various cellular biological processes, including the innate immune response. The immunoregulatory properties of numerous lncRNAs discovered in monocytes remain largely unexplored. Here, by RNA sequencing, we identified a lncRNA JHDM1D-AS1, which was upregulated in blood monocytes obtained from patients with sepsis relative to healthy controls. JHDM1D-AS1 expression was induced in primary human monocytes exposed to Toll-like receptor ligands, such as lipopolysaccharide (LPS), or bacteria. The inducibility of JHDM1D-AS1 expression in monocytes depended, at least in part, on nuclear factor-κB activation. JHDM1D-AS1 knockdown experiments in human monocyte-derived macrophages revealed significantly enhanced expression of inflammatory mediators, before and after exposure to LPS, relative to control cells. Specifically, genes involved in inflammatory responses were upregulated (e.g., CXCL2, CXCL8, IL1RN, TREM1, TNF, and IL6), whereas genes involved in anti-inflammatory pathways were downregulated (e.g., SOCS1 and IL10RA). JHDM1D-AS1 overexpression in a pro-monocytic cell line revealed diminished pro-inflammatory responses subsequent to LPS challenge. Collectively, these findings identify JHDM1D-AS1 as a potential anti-inflammatory mediator induced in response to inflammatory stimuli.

The RNA helicase DHX15 is a critical regulator of natural killer-cell homeostasis and functions

The RNA helicase DHX15 is widely expressed in immune cells and traditionally thought to be an RNA splicing factor or a viral RNA sensor. However, the role of DHX15 in NK-cell activities has not been studied thus far. Here, we generated Dhx15-floxed mice and found that conditional deletion of Dhx15 in NK cells (Ncr1^CreDhx15^fl/fl mice) resulted in a marked reduction in NK cells in the periphery and that the remaining Dhx15-deleted NK cells failed to acquire a mature phenotype. As a result, Dhx15-deleted NK cells exhibited profound defects in their cytolytic functions. We also found that deletion of Dhx15 in NK cells abrogated their responsiveness to IL-15, which was associated with inhibition of IL-2/IL-15Rβ (CD122) expression and IL-15R signaling. The defects in Dhx15-deleted NK cells were rescued by ectopic expression of a constitutively active form of STAT5. Mechanistically, DHX15 did not affect CD122 mRNA splicing and stability in NK cells but instead facilitated the surface expression of CD122, likely through interaction with its 3'UTR, which was dependent on the ATPase domain of DHX15 rather than its splicing domain. Collectively, our data identify a key role for DHX15 in regulating NK-cell activities and provide novel mechanistic insights into how DHX15 regulates the IL-15 signaling pathway in NK cells.

The Value of Dysregulated LncRNAs on Clinicopathology and Survival in Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Background: There is growing evidence that a number of lncRNAs are involved in the pathogenesis of non-small-cell lung cancer (NSCLC). However, studies on lncRNA expression in NSCLC patients are far from conclusive. Therefore, we performed a systematic review of such studies to collect and examine the evidence on the potential role of lncRNAs in the development of NSCLC.

Methods: We systematically searched seven literature databases to identify all published studies that evaluated the expression of one or more lncRNAs in human samples with NSCLC (cases) and without NSCLC (controls) from January 1, 1995 to May 24, 2021. Quality assessment of studies was conducted by using the “Quality in Prognosis Studies” (QUIPS) tool, and the heterogeneity across studies was analyzed with the I-squared statistic and chi-square-based Q-tests. Either fixed or random-effect meta-analysis was performed to summarize effect size to investigate the association between lncRNA expression and overall survival (OS), disease-free survival (DFS), progression-free survival (PFS), and clinicopathological features. The R statistical software program was used to conduct standard meta-analysis.

Results: We finally obtained 48 studies with 5,211 patients included in this review after screening. Among the 48 lncRNAs, 38 lncRNAs were consistently upregulated, and 10 were deregulated in patients with NSCLC compared with the control groups. The upregulated lncRNAs were positively associated with histological type: study number (n) = 18, odds ratio (OR) = 0.78, 95% CI: 0.65–0.95 and OR = 1.30, 95% CI: 1.08–1.57, p < 0.01; TNM stages: n = 20, OR = 0.41, 95% CI: 0.29–0.57 and OR = 2.44, 95% CI: 1.73–3.44, p < 0.01; lymph node metastasis: n = 29, OR = 0.49, 95% CI: 0.34–0.71 and OR = 2.04, 95% CI: 1.40–2.96, p < 0.01; differentiation grade: n = 6, OR = 0.61, 95% CI: 0.38–0.99 and OR = 1.63, 95% CI: 1.01–2.64, p < 0.01; distant metastasis: n = 9, OR = 0.37, 95% CI: 0.26–0.53 and OR = 2.72, 95% CI: 1.90–3.90, p < 0.01; tumor size: n = 16, OR = 0.52, 95% CI: 0.43–0.64 and OR = 1.92, 95% CI: 1.57–2.34, p < 0.01; and overall survival [n = 38, hazard ratio (HR) = 1.79, 95% CI = 1.59–2.02, p < 0.01]. Especially, five upregulated lncRNAs (linc01234, ZEB1-AS1, linc00152, PVT1, and BANCR) were closely associated with TNM Ⅲa stage (n = 5, OR = 4.07, 95% CI: 2.63–6.28, p < 0.01). However, 10 deregulated lncRNAs were not significantly associated with the pathogenesis and overall survival in NSCLC in the meta-analysis (p ≥ 0.05).

Conclusion: This systematic review suggests that the upregulated lncRNAs could serve as biomarkers for predicting promising prognosis of NSCLC. The prognostic value of downregulated lncRNA in NSCLC needs to be further explored.

Systematic Review Registration: (http://www.crd.york.ac.uk/PROSPERO).identifier CRD42021240635.

LncRNA JHDM1D-AS1 Suppresses MPP + -Induced Neuronal Injury in Parkinson's Disease via miR-134-5p/PIK3R3 Axis

Parkinson's disease (PD) is a multi-factorial neurodegenerative disease. Long noncoding RNAs (lncRNAs) have been revealed to be involved in the process of PD. Herein, this study aimed to investigate the potential function and mechanism of JHDM1D-AS1 (JHDM1D antisense 1) in PD process. 1-Methyl-4-phenylpyridinium (MPP +)-induced SK-N-SH cells were used to conduct expression and function analyses. Levels of genes and proteins were examined using real-time reverse transcription PCR (RT-qPCR) and Western blot. Cell viability and apoptosis were determined using CCK-8 assay, flow cytometry, and Western blot, respectively. ELISA analysis was performed for the detection of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. The contents of lactate dehydrogenase (LDH), superoxide dismutase (SOD), and malondialdehyde (MDA) were measured using commercial kits. The direct interactions between miR-134-5p and PIK3R3 (Phosphoinositide-3-Kinase Regulatory Subunit 3) or JHDM1D-AS1 were verified by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. JHDM1D-AS1 expression was decreased by MPP + in SK-N-SH cells in a dose- or time-dependent manner. Functionally, JHDM1D-AS1 overexpression attenuated MPP + -evoked neuronal apoptosis, inflammation, and oxidative stress. Mechanistically, JHDM1D-AS1 competitively bound to miR-134-5p to upregulate the expression of its target PIK3R3. Rescue experiments suggested that miR-134-5p upregulation reversed the inhibitory effects of JHDM1D-AS1 on MPP + -induced neuronal injury. Moreover, inhibition of miR-134-5p protected neurons against MPP + -induced neuronal apoptosis, inflammation, and oxidative stress, which were abolished by PIK3R3 silencing. JHDM1D-AS1 protected against MPP + -induced neuron injury via miR-134-5p/PIK3R3 axis, suggesting the potential involvement of this axis in PD process.

The loss of DHX15 impairs endothelial energy metabolism, lymphatic drainage and tumor metastasis in mice

DHX15 is a downstream substrate for Akt1, which is involved in key cellular processes affecting vascular biology. Here, we explored the vascular regulatory function of DHX15. Homozygous DHX15 gene deficiency was lethal in mouse and zebrafish embryos. DHX15-/- zebrafish also showed downregulation of VEGF-C and reduced formation of lymphatic structures during development. DHX15+/- mice depicted lower vascular density and impaired lymphatic function postnatally. RNAseq and proteome analysis of DHX15 silenced endothelial cells revealed differential expression of genes involved in the metabolism of ATP biosynthesis. The validation of these results demonstrated a lower activity of the Complex I in the mitochondrial membrane of endothelial cells, resulting in lower intracellular ATP production and lower oxygen consumption. After injection of syngeneic LLC1 tumor cells, DHX15+/- mice showed partially inhibited primary tumor growth and reduced lung metastasis. Our results revealed an important role of DHX15 in vascular physiology and pave a new way to explore its potential use as a therapeutical target for metastasis treatment.

Long non-coding RNA ZNF674-AS1 regulates miR-23a/E-cadherin axis to suppress the migration and invasion of non-small cell lung cancer cells

BACKGROUND

Non-small cell lung cancer (NSCLC) is one of the most common malignant tumors. The prognosis of patients with advanced NSCLC is poor due to metastasis. In recent years, the role of long non-coding RNAs (lncRNAs), a class of non-coding RNA molecules, in NSCLC has become an increasingly popular focus of studies. This study aimed to investigate the effects of ZNF674-AS1 and microRNA (miR)-23a on the migration and invasion abilities of NSCLC cells in vitro and explore the underpinning molecular mechanisms.

METHODS

The expression levels of ZNF674-AS1 and miR-23a in NSCLC tissues and cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Scratch test and transwell test were used to detect the effects of ZNF674-AS1 and miR-23a on the migration and invasion of NSCLC cells. The luciferase reporter gene experiment was used to verify miRNA targets. Western blot experiments were used to analyze protein expression.

RESULTS

ZNF674-AS1 was downregulated in NSCLC tissues and cells, and inhibited the migration and invasion of NSCLC cells in vitro. In contrast, the expression of miR-23a, a downstream target of ZNF674-AS1, was increased in NSCLC tissues and cells. We found that miR-23a could antagonize the role of ZNF674-AS1 in NSCLC. E-cadherin was identified as a downstream target gene of miR-23a, and miR-23a could directly inhibit its expression.

CONCLUSIONS

ZNF674-AS1 inhibits the migration and invasion of NSCLC cells by regulating a miR-23a/E-cadherin axis. ZNF674-AS1 and miR-23a could become potential therapeutic targets for NSCLC.

Long noncoding RNAs: role and contribution in pancreatic cancer

Noncoding RNAs are proclaimed to be expressed in various cancer types and one such type is found to be pancreatic ductal adenocarcinoma (PDAC). The long noncoding RNAs (LncRNAs) affect the migration, invasion, and growth of tumor cells by playing important roles in the process of epigenesis, post-transcription, and transcriptional regulation along with the maintenance of apoptosis and cell cycle. It is quite subtle whether the alterations in lncRNAs would impact PDAC progression and development. This review throws a spotlight on the lncRNAs associated with tumor functions: MALAT-1, HOTAIR, HOXA13, H19, LINC01559, LINC00460, SNHG14, SNHG16, DLX6-AS1, MSC-AS1, ABHD11-AS1, DUXAP8, DANCR, XIST, DLEU2, etc. are upregulated lncRNAs whereas GAS5, HMlincRNA717, MIAT, LINC01111, lncRNA KCNK15-AS1, etc. are downregulated lncRNAs inhibiting the invasion and progression of PDAC. These data provided helps in the assessment of lncRNAs in the development, metastasis, and occurrence of PDAC and also play a vital role in the evolution of biomarkers and therapeutic agents for the treatment of PDAC.

lncRNA LINC00473 promotes proliferation, migration, invasion and inhibition of apoptosis of non-small cell lung cancer cells by acting as a sponge of miR-497-5p

Lung cancer is the leading cause of cancer-associated death worldwide and exhibits a poor prognosis. The present study aimed to determine the effect of long non-coding (lnc)RNA-LINC00473 on the development of non-small cell lung cancer (NSCLC) cells by regulating the expression of microRNA (miR)-497-5p. Reverse transcription-quantitative PCR was conducted to detect the level of LINC00473 and miR-497-5p. An MTT assay, flow cytometry and Transwell tests were performed to evaluate the proliferation, apoptosis, migration and invasion of NSCLC cells. Western blotting was performed to detect the expression of apoptosis- and migration-related proteins. RNA immunoprecipitation and a luciferase reporter assay were performed to verify the regulatory relationship between lncRNA-LINC00473 and miR-497-5p. LINC00473 expression was upregulated in lung cancer tissues and NSCLC cells (A549 and H1299) when compared with adjacent tissues or human bronchial epithelial cell lines and the 5-year survival rate was lower in patients with high LINC00473 expression compared with in patients with low LINC00473 expression. A negative correlation between LINC00473 and miR-497-5p was observed in lung cancer tissues. Proliferation, migration and invasion as well as the related protein levels were increased in A549 and H1299 transfected with pcDNA3.1-LINC00473, while the opposite results were obtained in A549 and H1299 transfected with small interfering (si)-LINC00473. Notably, it was demonstrated that LINC00473 could bind directly with miR-497-5p and inhibit its expression. miR-497-5p inhibitors reversed the effect of si-LINC00473. Furthermore, the present study demonstrated that LINC00473 promoted the malignant behaviour of NSCLC cells via regulating the ERK/p38 and MAPK signalling pathways and the expression of miR-497-5p.

The metastasizing mechanisms of lung cancer: Recent advances and therapeutic challenges

Lung cancer is one of the common malignant tumors that threaten human life with serious incidence and high mortality. According to the histopathological characteristics, lung cancer is mainly divided into non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). NSCLC accounts for about 80-85% of lung cancers. In fact, lung cancer metastasis is a major cause of treatment failure in clinical patients. The underlying reason is that the mechanisms of lung cancer metastasis are still not fully understood. The metastasis of lung cancer cells is controlled by many factors, including the interaction of various components in the lung cancer microenvironment, epithelial-mesenchymal transition (EMT) transformation, and metastasis of cancer cells through blood vessels and lymphatics. The molecular relationships are even more intricate. Further study on the mechanisms of lung cancer metastasis and in search of effective therapeutic targets can bring more reference directions for clinical drug research and development. This paper focuses on the factors affecting lung cancer metastasis and connects with related molecular mechanisms of the lung cancer metastasis and mechanisms of lung cancer to specific organs, which mainly reviews the latest research progress of NSCLC metastasis. Besides, in this paper, experimental models of lung cancer and metastasis, mechanisms in SCLC transfer and the challenges about clinical management of lung cancer are also discussed. The review is intended to provide reference value for the future research in this field and promising treatment clues for clinical patients.

VPS33B modulates c-Myc/p53/miR-192-3p to target CCNB1 suppressing the growth of non-small cell lung cancer

VPS33B is reported to be a tumor suppressor in hepatocellular carcinoma, nasopharyngeal carcinoma, colon cancer, and lung adenocarcinoma. Here, we observed that reduced VPS33B protein level was an unfavorable factor that promoted the pathogenesis of non-small cell lung cancer (NSCLC) in clinical specimens. We achieved lentivirus-mediated stable overexpression of VPS33B in NSCLC cells. Increased VPS33B reduced cell cycle transition and cell proliferation of NSCLC cells in vivo and in vitro. Knocking down VPS33B restored cell growth. Mechanism analysis indicated that miR-192-3p was induced by VPS33B and acted as a tumor suppressor of cell growth in NSCLC. Further, c-Myc or p53 was identified as a transcription factor that bound to the miR-192-3p promoter and regulated its expression. miR-192-3p directly targeted cell cycle-promoted factor CCNB1 and suppressed NSCLC cell growth. VPS33B modulated c-Myc/p53/miR-192-3p signaling to target CCNB1 by reducing activation of the Ras/ERK pathway. Our study reveals a novel molecular basis for VPS33B as a tumor suppressor to participate in the pathogenesis of NSCLC.

ZNF674-AS1 antagonizes miR-423-3p to induce G0/G1 cell cycle arrest in non-small cell lung cancer cells

BACKGROUND

ZNF674-AS1, a recently characterized long noncoding RNA, shows prognostic significance in hepatocellular carcinoma and glioma. However, the expression and function of ZNF674-AS1 in non-small cell lung cancer (NSCLC) are unclear.

METHODS

In this work, we investigated the expression of ZNF674-AS1 in 83 pairs of NSCLC specimens and adjacent noncancerous lung tissues. The clinical significance of ZNF674-AS1 in NSCLC was analyzed. The role of ZNF674-AS1 in NSCLC growth and cell cycle progression was explored.

RESULTS

Our data show that ZNF674-AS1 expression is decreased in NSCLC compared to normal tissues. ZNF674-AS1 downregulation is significantly correlated with advanced TNM stage and decreased overall survival of NSCLC patients. Overexpression of ZNF674-AS1 inhibits NSCLC cell proliferation, colony formation, and tumorigenesis, which is accompanied by a G0/G1 cell cycle arrest. Conversely, knockdown of ZNF674-AS1 enhances the proliferation and colony formation of NSCLC cells. Biochemically, ZNF674-AS1 overexpression increases the expression of p21 through downregulation of miR-423-3p. Knockdown of p21 or overexpression of miR-423-3p blocks ZNF674-AS1-mediated growth suppression and G0/G1 cell cycle arrest. In addition, ZNF674-AS1 expression is negatively correlated with miR-423-3p in NSCLC specimens.

CONCLUSIONS

ZNF674-AS1 suppresses NSCLC growth by downregulating miR-423-3p and inducing p21. This work suggests the therapeutic potential of ZNF674-AS1 in the treatment of NSCLC.

Systematic analysis using a bioinformatics strategy identifies SFTA1P and LINC00519 as potential prognostic biomarkers for lung squamous cell carcinoma

Lung cancer has high incidence and mortality rates, in which lung squamous cell carcinoma (LUSC) is a primary type of non-small cell lung carcinoma (NSCLC). The aim of our study was to discover long non-coding RNAs (lncRNAs) associated with diagnose and prognosis for LUSC. RNA sequencing data obtained from LUSC samples were extracted from The Cancer Genome Atlas database (TCGA). Two prognosis-associated lncRNAs (including SFTA1P and LINC00519) were selected from LUSC samples, and the expression levels were also verified to be associated abnormal in LUSC clinical samples. Our findings demonstrate that lncRNAs SFTA1P and LINC00519 exert important functions in human LUSC and may serve as new targets for LUSC diagnosis and therapy.

A six-long noncoding RNA model predicts prognosis in lung adenocarcinoma

Background

The incidence and mortality of lung cancer rank first among various malignant tumors. The lack of clear molecular classification and effective individualized treatment greatly limits the treatment benefits of patients. Long non-coding RNAs (lncRNAs) have been demonstrated widely involve in tumor progressing, and been proved easy to detect for occupying majority in transcriptome. However, less work focuses on studying the potency of lncRNAs as molecular typing and prognostic indicator in lung cancer.

Methods

Based on the 448 lung adenocarcinoma (LUAD) samples and the expression of 14,127 lncRNAs from the Cancer Genome Atlas (TCGA) database, we constructed a co-expression network using weighted gene co-expression network analysis. Then based on the feature module and the overall survival of patients, we constructed a risk score model through Cox proportional hazards regression and verified it with a validation cohort. Finally, according to the median of risk score, the function of this model was enriched.

Results

We identified a module containing 123 lncRNAs that is related with the prognosis of LUAD. Using univariate and multivariate Cox proportional hazards regression with lasso regression, six lncRNAs were identified to construct a risk score model. The calculation formula shown as follows: risk score = (−0.3057 × EXP_VIM-AS1) + (0.9678 × EXP_AC092811.1) + (1.0829 × EXP_NFIA-AS1) + (−0.3505 × EXP_AL035701.1) + (3.9378 × EXP_AC079336.4) + (−0.2810 × EXP_AL121790.2). Six-lncRNA model can be used as an independent prognostic indicator in LUAD (P<0.001) and the area under the 5-year receiver operating characteristic (ROC) curve is 0.715.

Conclusions

We developed a six-lncRNA model, which could be used for predicting prognosis and guiding medical treatment in LUAD patients.

JHDM1D-AS1 aggravates the development of gastric cancer through miR-450a-2-3p-PRAF2 axis

AIMS

To investigate the molecular function and mechanisms of JHDM1D antisense 1 (JHDM1D-AS1) during gastric cancer (GC) progression.

MATERIALS AND METHODS

The qPCR assay was used to detect the JHDM1D-AS1 and miR-450a-2-3p expression levels in GC tissues and cell lines. Bioinformatics analysis was used for exploring the lncRNA-microRNA-mRNA interaction network. We performed dual-luciferase reporter assay and qPCR assay in order to validate the direct interactions. We explored the JHDM1D-AS1 and miR-450a-2-3p on GC progression by using JHDM1D-AS1 siRNA and miR-450a-2-3p inhibitor; in vitro CCK-8 assay, colony formation assay, and invasion assay were conducted. Further, in vivo animal experiments were performed, and the expression levels of miR-450a-2-3p and PRAF2 in the tumor tissues were detected using qPCR and western blot analysis.

KEY FINDINGS

The expression levels of JHDM1D-AS1 and miR-450a-2-3p in GC tissues and cell lines were higher and lower as compared to those in the corresponding normal controls, respectively. Moreover, high levels of JHDM1D-AS1 were closely related with metastasis and the GC TNM stage. Functionally, JHDM1D-AS1 depletion caused an obvious reduction in cell proliferation and invasion both in vitro and in vivo, while the addition of miR-450a-2-3p inhibitor could nullify these effects. Mechanically, JHDM1D-AS1 promoted GC progression via the sponging of miR-450a-2-3p in order to increase PRAF2 expression.

SIGNIFICANCE

The present results showed that the increased expression of JHDM1D-AS1 was closely associated with tumor progression of GC. JHDM1D-AS1/miR-450a-2-3p/PRAF2 axis may be a promising target for GC treatment.

Identification of key genes and biological pathways in lung adenocarcinoma via bioinformatics analysis

Lung adenocarcinoma (LUAD) accounts for the majority of cancer-related deaths worldwide. Our study identified key LUAD genes and their potential mechanism via bioinformatics analysis of public datasets. GSE10799, GSE40791, and GSE27262 microarray datasets were retrieved from the Gene Expression Omnibus (GEO) database. The RobustRankAggreg package was used to perform a meta-analysis, and 50 upregulated genes and 87 downregulated genes overlapped in three datasets. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using the Database for Annotation, Visualization, and Integrated Discovery (DAVID). Furthermore, protein-protein interaction (PPI) networks of the differentially expressed genes (DEGs) were built by the Search Tool for the Retrieval of Interacting Genes (STRING) and 22 core genes were identified by Molecular Complex Detection (MCODE) and visualized with Cytoscape. Subsequently, these core genes were analyzed by the Kaplan-Meier Plotter and Gene Expression Profiling Interactive Analysis (GEPIA). The results showed that all 22 genes were significantly associated with reduced survival rates. For GEPIA, the expression of only one gene was not significantly different between LUAD tissues and normal tissues. A KEGG pathway enrichment reanalysis of the 21 genes identified five key genes (CCNB1, BUB1B, CDC20, TTK, and MAD2L1) in the cell cycle pathway. Finally, the Comparative Toxicogenomics Database (CTD) website was used to explore the relationship between these key genes and certain drugs. Based on the bioinformatics analysis, five key genes were identified in LUAD, and drugs closely associated these genes can provide clues for the treatment and prognosis of LUAD.

Upregulation of JHDM1D-AS1 alleviates neuroinflammation and neuronal injury via targeting miR-101-3p-DUSP1 in spinal cord after brachial plexus injury

BACKGROUND

Neuroinflammation in the spinal cord following acute brachial plexus injury (BPI) remains a vital cause that leads to motor dysfunction and neuropathic pain. In this study, we aim to explore the role of long non-coding RNA JHDM1D antisense 1 (JHDM1D-AS1) in mediating BPI-induced neuroinflammation and neuronal injury.

METHODS

A total brachial plexus root avulsion (tBPRA) model in adult rats and IL-1β-treated motor neuron-like NSC-34 cells and LPS-treated microglia cell line BV2 were conducted for in vivo and in vitro experiments, respectively. The expressions of JHDM1D-AS1, miR-101-3p and DUSP1, p38, NF-κB, TNF-α, IL-1β, and IL-6 were detected by RT-PCR and western blot seven days after tBPI. Immunohistochemistry (IHC) was used to detect neuronal apoptosis. CCK8 assay, Tunel assay and LDH kit were used for the detection of neuronal injury. The targeted relationships between JHDM1D-AS1 and miR-101-3p, miR-101-3p and DUSP1 were verified by RNA immunoprecipitation (RIP) and dual-luciferase reporter gene assay.

RESULTS

We found significant downregulated expression of JHDM1D-AS1 and DUSP1 but upregulated expression of miR-101-3p in the spinal cord after tBPI. Overexpression of JHDM1D-AS1 had a prominent neuroprotective effect by suppressing neuronal apoptosis and microglial inflammation through reactivation of DUSP1. Further exploration revealed that JHDM1D-AS1 may act as a competitive endogenous RNA targeting miR-101-3p, which bound on the 3'UTR of DUSP1 mRNA. In addition, overexpression of miR-101-3p could reverse the neuroprotective effects of JHDM1D-AS1 upregulation by blocking DUSP1.

CONCLUSIONS

JHDM1D-AS1 exerted neuroprotective and anti-inflammatory effects in a rat model of tBPI by regulating miR-101-3p/DUSP1 axis.

m6 A transferase METTL3-induced lncRNA ABHD11-AS1 promotes the Warburg effect of non-small-cell lung cancer

N⁶ -methyladenosine (m⁶ A) and long noncoding RNAs (lncRNAs) are both crucial regulators in non-small-cell lung cancer (NSCLC) tumorigenesis. However, the pathological roles of m⁶ A and lncRNAs in NSCLC progression are still limited and undefined. Here, lncRNA ABHD11-AS1 was upregulated in NSCLC tissue specimens and cells and the ectopic overexpression was closely correlated with unfavorable prognosis of NSCLC patients. Functionally, ABHD11-AS1 promoted the proliferation and Warburg effect of NSCLC. Mechanistically, m⁶ A profile was analyzed by methylated RNA immunoprecipitation sequencing (MeRIP-Seq). MeRIP-Seq presented that there was m⁶ A modification site in ABHD11-AS1. m⁶ A methyltransferase-like 3 (METTL3) installed the m⁶ A modification and enhanced ABHD11-AS1 transcript stability to increase its expression. In conclusion, our findings highlight the function and mechanism of METTL3-induced ABHD11-AS1 in NSCLC and inspire the understanding of m⁶ A and lncRNA in cancer biology.

LncRNA UCA1 promotes cisplatin resistance in gastric cancer via recruiting EZH2 and activating PI3K/AKT pathway

Background: Drug resistance of cancer cells is one of the major causes of chemotherapy failure. Recently research demonstrated that long non-coding RNA Urothelial cancer associated 1 (UCA1) could promote tumor cisplatin resistance. In this study, we aim to investigate the role of UCA1 in the cisplatin treatment of gastric cancer and its underlying mechanism. Methods: Cell counting kit-8 (CCK-8) assay and apoptosis assay were used to detect the effects of different doses of cisplatin on the proliferation and apoptosis of gastric cancer. We examined the expression relationship between the Enhancer of Zeste Homologue 2 (EZH2) and UCA1 by quantitative Real-time polymerase chain reaction (qRT-PCR) and western blot analysis. Western blot analysis was also performed to detect the expression levels of apoptosis-related proteins, EZH2 and key genes in PI3K/AKT signaling pathway, RIP and RNA pull down assays were performed to explore the interaction between UCA1 and EZH2. Results: We demonstrated that higher the UCA1 expression levels in GC tissues correlated with the poorer the prognosis of patients according to the TCGA database, the GEO database. Moreover, overexpression of UCA1 promotes GC cell proliferation and inhibits cisplatin-induced apoptosis. Knockdown of UCA1 showed the opposite results. Besides, UCA1 exerted its function through interacting with EZH2 and regulates EZH2 expression, knockdown of EZH2 decreased cisplatin resistance of GC cells. Hence, UCA1 promotes cisplatin resistance of GC via recruiting EZH2 and activating PI3K/AKT pathway. Conclusion: Our research revealed the lncRNA UCA1 promoted the cisplatin resistance of GC by recruiting EZH2 and activating PI3K/AKT pathway to modulate cell apoptosis, indicating treatments targeting UCA1 or EZH2 might provide meaningful therapeutic strategies for cisplatin-resistance GC patients.

LncRNA MALAT1 Regulates the Cell Proliferation and Cisplatin Resistance in Gastric Cancer via PI3K/AKT Pathway

Background

Many studies showed that long non-coding RNA MALAT1 is served as an oncogene. However, the specific role of MALAT1 in gastric cancer is not fully elucidated. The aim of this study is to elucidate the regulatory effects of MALAT1 on tumor development and cisplatin resistance in gastric cancer.

Methods

TCGA database was applied to investigate the expression levels of MALAT1 in GC tissues and normal gastric tissues and its correlation with GC patients’ survival. Univariate and multivariate analysis were performed to investigate whether MALAT1 expression is an independent risk for overall survival of gastric cancer patients. The expression of MALAT1 was detected by Quantitative real-time PCR. After knockdown or overexpression of MALAT1, the cellular functions of GC cells were detected by cell-proliferation, flow cytometry, transwell assay and colony formation assays, respectively. Western blot analysis was performed to detect the protein levels of Bcl-2 and key genes in the PI3K/AKT pathway in GC cells. Finally, CCK-8 assay was performed to explore the effect of MALAT1 on cisplatin resistance of GC cells.

Results

Higher expression of MALAT1 was detected in GC tissues than that of adjacent normal tissues, high MALAT1 expression is an independent risk for overall survival of gastric cancer patients. Knockdown of MALAT1 inhibited proliferation, migration and invasion of GC cells, while overexpression of MALAT1 Overexpression of MALAT1 yielded opposite results. Western blot results showed that protein expressions of p-PI3K, p-AKT and p-STAT3 were downregulated after MALAT1 knockdown in GC cells, while these proteins were upregulated after MALAT1 overexpression. Additionally, the IC₅₀ in MGC803/CDDP cells transfected with si-MALAT1 was lower than in those transfected with si-NC. The apoptotic rate in MGC803 cells transfected with pcDNA-MALAT1 was remarkably lower than those transfected with NC.

Conclusion

We demonstrated that MALAT1 is highly expressed in GC, high MALAT1 expression is an independent risk factor for OS among GC patients. Moreover, MALAT1 promotes malignant progression of GC and contributes to cisplatin resistance of GC cells, indicating MALAT1 may serve as a biological hallmark for predicting the prognosis of GC.