Metastasis-associated Lung Adenocarcinoma Transcript Research Articles

Abstract B021: tRNA fragments extracted from patient plasma extra cellular vesicles display potential as biomarkers for high-grade glioma

Abstract Transfer RNA (tRNA) are non-coding RNAs that bring amino acids to ribosomes during translation. Recent studies have shown that cleaved fragments derived from tRNA (tRFs) serve regulatory roles in epigenetics, signaling, transcription, and translation. tRFs can be released from cells and can be found in extracellular vesicles to perform some aspects of paracrine signaling. Utilizing high throughput small RNA sequencing, we have identified over 750 uniquely or multi-mapped (6.9% of total sRNA mapped reads) tRFs in extracellular vesicles of high-grade glioma (IDH-WT) patient plasma. By performing differential expression analysis, we identified 6 upregulated tRFs and 36 downregulated tRFs between high-grade glioma plasma EVs and non-cancer controls (n = 14, FDR<0.05). Differentially expressed tRFs (all 42) were further analyzed using bioinformatic techniques (RNAhybrid and IntaRNA) to predict potential gene targets. By performing gene ontology analysis (ShinyGO) we found that 70 of 75 genes related to glioma formation were identified as potential gene targets, indicating a possible role of tRFs in the regulation and formation of gliomas. A number of differentially expressed tRFs were predicted to target cancer-related genes including Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT-1). This analysis demonstrates that tRFs may serve as important biomarkers and regulators with therapeutic potential in the future Citation Format: Thomson R Phinney, Ali Alwadei, Gabriel Gabriel Wajnberg, Jae Han, Simi Chacko, Kathleen Attwood, Jeremy Roy, Adriennne Weeks. tRNA fragments extracted from patient plasma extra cellular vesicles display potential as biomarkers for high-grade glioma [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr B021.

LncRNA MALAT1 promotes Erastin-induced ferroptosis in the HBV-infected diffuse large B-cell lymphoma.

In a retrospective analysis of clinical data from 587 DLBCL (diffuse large B-cell lymphoma) patients in China, 13.8% of cases were associated with HBV (hepatitis B virus) infection, leading to distinct clinical features and poorer prognosis. Moreover, HBV infection has a more pronounced impact on the survival of the GCB (germinal center B-cell-like) type DLBCL patients compared to the ABC (activated B-cell-like) type. In this study, we found that the expression of LncRNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) was downregulated in the HBV-infected GCB-type DLBCL patients, and the HBV core protein (HBX) directly inhibited the MALAT1 expression in DLBCL cells. Notably, the overexpression of HBX could attenuate the Erastin-induced ferroptosis in the GCB-type DLBCLs, while MALAT1 re-expression restored sensitivity in the HBX-overexpressing DLBCLs in vitro and in vivo. Mechanistically, MALAT1 competitively hindered SFPQ (splicing factor proline and glutamine-rich) from effectively splicing the pre-mRNA of SLC7A11 (solute carrier family 7 member 11), due to a shared TTGGTCT motif, which impeded the SLC7A11 pre-mRNA maturation and hence diminished its negative regulation on ferroptosis. Together, our study identified HBX's role in inhibiting MALAT1 expression, promoting SFPQ-mediated splicing of SLC7A11 pre-mRNA, and reducing the GCB-type DLBCL sensitivity to Erastin-induced ferroptosis. Combined with the recent studies that ferroptosis may be involved in the occurrence and development of DLBCL, these findings explain our clinical data analysis that DLBCL patients with low expression of MALAT1 have poorer prognosis and shorter overall survival, and provide a valuable therapeutic target for the HBV-infected GCB-type DLBCL patients.

LncRNA MALAT1 silencing represses CXCL12-induced proliferation, invasion, and homing behavior in multiple myeloma by inhibiting CXCR4

ABSTRACT Background: Long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been identified in multiple myeloma (MM); its influence on the homing behavior in MM cells is unclear. This study elucidates the impact and mechanism by which MALAT1 affects the homing behavior in MM cells. Methods: Bone marrow was obtained from patients with MM. MALAT1 and C-X-C motif chemokine receptor 4 (CXCR4) expression in cluster of differentiation 138-purified (CD138) plasma cells were detected by qRT-PCR and Western blotting. MALAT1, CXCR4, and C-X-C motif chemokine ligand 12 (CXCL12) influences on MM cell viability, proliferation, and invasion was monitored by CCK-8, 5-Ethynyl-2'-deoxyuridine, and Transwell assays. qRT-PCR, Western blotting, and ELISA were utilized to detect homing effect-related proteins in MM cells, including intercellular adhesion molecule 1 (ICAM-1) and very late antigen-4 (VLA-4). Results: MALAT1 and CXCR4 were overexpressed in CD138-purified plasma cells from bone marrow of MM patients, associating with bone damage. MALAT1 upregulated CXCR4 in MM cells. MALAT1 overexpression enhanced MM cell viability, proliferation, and invasion, whereas CXCR4 silencing reversed them. CXCR4 silencing attenuated MALAT1 induction on ICAM-1 and VLA-4 expression in MM cells. CXCL12 upregulation intensified MM cell proliferation and invasion and ICAM-1 and VLA-4 expression in MM cells. MALAT1 silencing counteracted the impact of CXCL12. Conclusion: MALAT1 silencing may repress CXCL12 induction on MM cell proliferation, invasion, and homing behavior by inhibiting CXCR4. MALAT1 may be a promising target for MM treatment.

LncRNA MALAT1 as diagnostic and prognostic biomarker in colorectal cancers: A systematic review and meta-analysis.

This study investigated the relationship between the long non-coding RNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 (MALAT1) expression and colorectal cancer (CRC) using a thorough systematic review and meta-analysis. Under the PRISMA guidelines, a systematic review was conducted on studies published from the databases' inception to September 18, 2023. Prognostic value and diagnostic accuracy were explored. Additionally, the association between levels of MALAT1 expression and pathological features was investigated. The statistical analysis was performed using the "meta" package of R. Among the pathological parameters examined, based on three studies involving 51 cases of metastatic CRC and 135 cases of non-metastatic CRC, a statistically significant correlation was found between the expression level of MALAT1 and distant metastasis, with an OR of 16.0118 (95% CI: 4.5618-56.2015). Three studies involving 378 cases reported overall survival and had a pooled HR of 2.3854 (95% CI: 1.3272-4.2875). Three studies involving 436 cases reported disease-free survival and had a pooled HR of 2.4772 (95% CI: 1.3774-4.4549). All prognosis studies utilized tumor tissue samples as specimens to assess the expression level of MALAT1. Case-to-control diagnostic studies with 126 cases and 126 controls had a pooled AUC value of 0.6173 (95% CI: 0.5436-0.6909), a pooled sensitivity of 0.675 (95% CI: 0.324-0.900), and a pooled specificity of 0.771 (95% CI: 0.685-0.839). The expression of MALAT1 in CRC is highly correlated with distant metastasis and has an impact on survival and prognosis. MALAT1 could also be employed as a diagnostic biomarker. More prospective studies should be performed to assess the MALAT1 diagnostic potential in the early stages of CRC.

Exploring the Dual Role of MALAT1 in Thyroid Tumorigenesis: Oncogenic or Tumor Suppressor?

Thyroid cancer is the most prevalent form of endocrine cancer. Therefore, the administration of new therapeutic agents for thyroid cancer patients is necessary. One of the recent successes in thyroid cancer research is the identification of the role of signaling pathways in the pathogenesis of the disease. Emerging evidence reveals that long non-coding RNAs (lncRNAs) can serve as novel therapeutic approaches for the diagnosis and treatment of thyroid cancer. The lncRNA metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) plays key roles in gene expression, RNA processing, and epigenetic regulation. It is believed that MALAT1 can regulate several cancer-related processes, including tumour cell growth, proliferation, and metastasis. MALAT1 is involved in the pathogenesis of thzroid cancers by targeting multiple downstream targets and miRNA/mRNA axes. Here, we summarize the emerging roles of MALAT1 in this cancer.

LncRNA MALAT1 facilitates Parkinson's disease progression by increasing SOCS3 promoter methylation.

Long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been shown to be involved in Parkinson's disease (PD) progression, but its mechanism needs to be further explored. Mice were injected with 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to induce PD mice models, and BV2 cells were treated with lipopolysaccharides (LPS) to mimic PD cell models. MALAT1 expression and suppressor of cytokine signaling 3 (SOCS3) protein level were examined using quantitative real-time PCR and western blot, respectively. Cell functions were tested by cell counting kit 8 assay and flow cytometry. The interaction between MALAT1 and SOCS3 was confirmed using RNA pull-down and RIP assays. MALAT1 was upregulated in MPTP-induced PD mice and LPS-induced BV2 cells. Silencing of MALAT1 increased viability, while inhibited apoptosis and inflammation in LPS-induced BV2 cells. Besides, MALAT1 enhanced the SOCS3 promoter methylation to decrease its expression by recruiting DNMT1, DNMT3A and DNMT3B. Furthermore, SOCS3 knockdown eliminated sh-MALAT1-mediated the inhibition effect on LPS-induced BV2 cell injury. In vivo, MALAT1 silencing ameliorated neurological impairment and neuroinflammation in MPTP-induced PD mice. Our data revealed that MALAT1 worsened PD processes via inhibiting SOCS3 expression by increasing its promoter methylation.

Metastasis-Associated Lung Adenocarcinoma Transcript 1 (MALAT1) lncRNA Conformational Dynamics in Complex with RNA-Binding Protein with Serine-Rich Domain 1 (RNPS1) in the Pan-cancer Splicing and Gene Expression.

Alternative splicing events increase the transcriptomic and proteomic complexity in cancers. Overexpression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a highly conserved lncRNA, is widely known to promote cancer development, one mechanism for which may be through the regulation of alternative splicing and, thereby, gene expression. Its regulatory interactions with proteins have been a subject of much interest, yet little research has been carried out on the mechanisms adopted. It has been observed that MALAT1 binds to RNA-binding protein with serine-rich domain 1 (RNPS1), being colocalized in the nuclear speckles, and together, these two binding partners may regulate alternative splicing. Upregulated RNPS1 is predicted to play a key role in the pan-cancer development. Experimental tertiary structure of full-length MALAT1 is currently lacking despite the availability of the 3D structure of 3' expression and nuclear retention element. We hypothesize that the computationally modeled tertiary structures of the specific binding motifs in the M-region, E-region, and full-length structures of MALAT1 may adopt a modular structure and bind to the RNPS1 loop region of RS/P domain involved in exon skipping, interacting in a manner fully consistent with the biochemical experiments. Extensive observations using the powerful molecular dynamics (MD) simulations of MALAT1 regions bound to RNPS1 suggested that all three regions form interactive, yet stable complexes. The ranking of the MM-GBSA- and MM-PBSA-derived binding free energies between these complexes corroborated well in the MD simulations and experiments. Energy decomposition analyses suggested that arginines in the RNPS1 protein are among the major contributors toward the binding free energies as calculated by MM-GBSA present in the Amber package; while among the nucleotides, the major contributors were nucleotides with G and A nucleobases, with more contributory effect in comparison to arginines, across the bound M-region, E-region, and full-length MALAT1. This suggests that specific purines play a greater role in the complex formation, in a loop-specific manner, and the more proactive approach in complexation tilts toward MALAT1. To the best of our knowledge, our studies are the first studies taking a unique approach, utilizing the binding motifs to deduce a tertiary structure of MALAT1, toward our understanding of the lncRNA-protein interactions, stability, and binding on a structural basis. The therapeutic implications of targeting this complex formation to regulate splicing and hence, oncogenesis, is further envisaged.

Long non-coding RNA MALAT1 triggers ferroptosis via interaction with FUS to enhance ACSF2 mRNA stabilization in septic acute kidney injury.

Septic acute kidney injury (AKI) is a fatal disease in the intensive care unit, with ferroptosis playing a crucial role in its pathogenesis. Long non-coding RNA (LncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been implicated in septic-induced AKI inflammation and apoptosis. However, its regulatory role in ferroptosis and underlying mechanisms remain unclear. In vivo and in vitro models of septic AKI were established using cecal ligation and puncture (CLP) and lipopolysaccharide (LPS) challenge, respectively. Serum levels of creatinine (Cr), blood urea nitrogen (BUN), kidney injury molecule-1 (Kim-1), neutrophil gelatinase-associated lipocalin (NGAL), and inflammatory cytokine in kidney tissues were determined by ELISA kits. Histopathological alterations and apoptosis were evaluated by HE staining and TUNEL. Ferroptosis was accessed by measuring MDA, GSH, Fe2+, total and lipid ROS levels, and mitochondrial ultrastructure changes. Target molecular levels were determined using RT-qPCR, Western blotting, and immunofluorescence. Interactions among MALAT1, acyl-CoA synthetase family member 2 (ACSF2) and FUS RNA binding protein (FUS) were validated by RIP and RNA-pull down. MALAT1 level was significantly elevated in both in vivo and in vitro septic AKI models, of which knockdown impeded ferroptosis to alleviate septic AKI. Mechanistically, high MALAT1 expression increased ACSF2 mRNA stability via interaction with FUS. Rescue experiments showed that ACSF2 overexpression partially reversed the ferroptosis inhibition mediated by MALAT1 silencing. MALAT1 induces ferroptosis and exacerbates septic AKI by stabilizing ACSF2 mRNA with the assistance of FUS. These findings provide theoretical evidence for MALAT1 as a potential therapeutic target for septic AKI.

Inhibition of the long non-coding RNA MALAT1 downregulates MAP2K1 to suppress the progression of hypopharyngeal squamous cell carcinoma.

This study aimed to explore the role of lncRNA MALAT1 (Long non-coding RNAs metastasis-associated lung adenocarcinoma transcript), and its underlying mechanisms in Hypopharyngeal Squamous Cell Carcinoma (HSCC). Quantitative real-time PCR (qRT-PCR) was employed to measure lncRNA MALAT1 expression in HSCC and adjacent non-cancerous tissues, along with the expression of the downstream target mitogen-activated protein kinase kinase 1 (MAP2K1). The independent prognostic significance of lncRNA MALAT1 was assessed using Cox regression analysis. Potential downstream targets of MALAT1 were identified through PRM analysis and validated using the TCGA-HNSC database, Western blotting, and immunohistochemistry. CCK-8, flow cytometry, and Transwell assays were conducted to assess the effects of the lncRNA MALAT1/MAP2K1 axis on FaDu cells. Additionally, a nude mouse xenograft model was used to confirm the role of lncRNA MALAT1/MAP2K1 in tumor growth. LncRNA MALAT1 was significantly upregulated in HSCC tissues and closely associated with poor prognosis. Bioinformatics analysis, including parallel reaction monitoring (PRM) screening and TCGA-HNSC data, identified FERMT2, CSNK2A2, and MAP2K1 as potential downstream targets of MALAT1. Validation through qPCR, Western blotting, and immunohistochemistry confirmed MAP2K1 as a downstream target. In vitro and in vivo experiments demonstrated that inhibiting lncRNA MALAT1 suppressed cell proliferation, migration, and epithelial-to-mesenchymal transition (EMT) by downregulating MAP2K1 expression. Additionally, it induced apoptosis, affected the cell cycle, and inhibited tumor growth. Our study uniquely demonstrates that targeting MALAT1 significantly impedes HSCC progression by downregulating its novel downstream target, MAP2K1, offering new insights into potential therapeutic strategies.

Abstract C109: Identifying a novel metabolic reprogramming strategy to inhibit diabetes-associated TNBC in African American

Abstract Cancer cells have an increased glucose metabolism, primarily characterized by augmented glucose uptake and aerobic glycolysis, converting glucose into pyruvate, eventually producing lactate. Breast cancer (BC) is the most commonly diagnosed cancer and the second leading cause of death among women in the United States. The triple-negative breast cancer (TNBC) subgroup is the most aggressive, metastatic, and refractory because of the absence of the three characteristic receptors: Estrogen (ER), progesterone (PR), and human epidermal growth factor (Her2/neu), representing approximately 10-15% of all BC cases. Racial disparities analysis demonstrates that African American (AA) has a higher incidence of TNBC subtype, with an earlier onset, more advanced stage, more aggressive histologic features, and poor survival, compared to other ethnic groups. Hyperglycemia affects the cancer progression through metabolic reprogramming and molecular alterations. AA women with Type 2 diabetes (T2D) are at increased risk of developing ER-negative BC. The reasonable combination therapy of metformin with NF-𝜅Bi and MCT4i, is promising because it can rapidly disable tumor cell growth but with a minor effect on normal cells, holding promise as an anti-BC treatment. Because of the potential side effects of MCT4 inhibitors and the potent inhibitory effect of microRNA on target genes, we consider using microRNA instead of inhibitors to suppress MCT4 expression. We will investigate the anti-diabetes-associated TNBC effect of the MRS, consisting of blocking lactate export via MCT4 degradation by miR-206, in combination with promoting lactate production via forcing glycolysis with metformin and NF-𝜅Bi treatment, in a preclinical study of AA women. Moreover, our previous study and other studies have also shown an elevated expression of Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) in BC tissues and cells, particularly in metastatic TNBC. We will also explore the molecular mechanisms by which high glucose (HG) leads to lactate accumulation in BC cells. Our overall strategy is that excessive glucose uptake upregulates the MCT4 through a MALAT1/miR-206/MCT4 axis, miR-206-directed MRS shifts glucose metabolism from Oxidative phosphorylation (OXPHOS) to glycolysis, increasing lactate production. Meanwhile, blocking the export of excessive lactate through MCT4 degradation causes high intracellular lactate accumulation and a decrease in intracellular pH (pHi), resulting in metabolic crisis and BC cell death. Due to a complex interplay between hyperglycemia and cancer, antihyperglycemic drugs have often been devised in combination with anticancer drugs for cancer treatment. Our proposed approach will broadly impact the field by providing a novel idea for therapies targeting cancer cell lactate metabolism. In the long term, these studies may reveal an effective therapeutic strategy for diabetes-associated BC, especially in AA women. Citation Format: Qiongyu Hao, Yong Wu, Yanyuan Wu, Jaydutt Vadgama. Identifying a novel metabolic reprogramming strategy to inhibit diabetes-associated TNBC in African American [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C109.

Investigation of the expression of long non-coding RNA in Parkinson’s disease

BackgroundParkinson’s disease is the second most common age-related neurodegenerative disease after Alzheimer’s. Pathogenic factors in Parkinson’s include inflammation and oxidative stress, which lead to dopaminergic cell apoptosis. The case–control study aims to determine the expression level of long non-coding RNAs (lncRNAs) of the apoptosis pathway in Parkinson’s patients compared to healthy individuals. In the case–control study, 50 patients with Parkinson’s disease were examined, along with 50 healthy individuals matched in age and sex. In both groups, the expression of long non-coding RNAs, including taurine upregulated 1 (TUG1), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), nuclear-enriched abundant transcript 1 (NEAT1), and growth arrest-specific 5 (GAS5), was compared using real-time polymerase chain reaction (PCR).ResultsThe ratio of MALAT1, NEAT1, and TUG1 gene expression in the case group was statistically significantly higher than in healthy individuals. The ratio of GAS5 gene expression in people with Parkinson’s disease was lower, with a statistically significant difference. The ratio of HULC gene expression was higher in the case group, but it did not show a statistically significant difference with the control group.ConclusionThe involvement of long lncRNAs that increase apoptosis may play a role in the pathogenesis of the disease, which may be used for identification and therapeutic purposes.

Sequential changes in expression of long non-coding RNAs THRIL and MALAT1 after ischemic stroke.

Background: Inflammation is the major contributor to the pathophysiology of ischemic stroke (IS). Long non-coding ribonucleic acids (lncRNAs) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and tumor necrosis factor and heterogeneous nuclear ribonucleoprotein L-related immunoregulatory (THRIL) have been demonstrated to be up-regulated in inflammation and atherosclerosis. Therefore, we aimed to study the expression profile of these lncRNAs after IS. Methods: This observational case-control study was conducted in Namazi Hospital, Shiraz, Iran. The real-time polymerase chain reaction (RT-PCR) measured the sequential changes in circulating levels of MALAT1 and THRIL on days 1, 3, and 5 after IS. The receiver operating characteristic (ROC) curve analysis was used to estimate the diagnostic and prognostic potential of lncRNAs with the area under the curve (AUC). Results: In patients with IS, the relative MALAT1 and THRIL expressions were significantly higher than the controls (P < 0.001 and P < 0.01, respectively), on days 1, 3, and 5 after stroke. We showed a significantly increase in lncRNAs expression on day five compared to days 1 and 3 after stroke. Moreover, a positive correlation was detected between MALAT1 expression and time within the first 24 hours after stroke (r = 0.27, P = 0.03). Logistic regression analysis showed a significant positive association between MALAT1 and THRIL and the risk of stroke evolution. We found a potential diagnostic marker for MALAT1 with an AUC of 0.78. Conclusion: We demonstrated the significant sequential upregulation in MALAT1 and THRIL expression on days 1, 3, and 5 after IS with a significant positive association with the risk of stroke. MALAT1 also significantly correlated with time within the first 24 hours after stroke.

Clinical relevance of long non-coding RNA in acute myeloid leukemia: A systematic review with meta-analysis

BackgroundLong noncoding RNAs (lncRNAs) may function as prognostic biomarkers in acute myeloid leukaemia (AML). However, it is still unknown exactly how significant lncRNAs are for the prognosis of AML. With a focus on their prognostic and therapeutic potential, the study aimed to provide a comprehensive review of the literature regarding the role of lncRNAs in AML. MethodPub Med, The Cochrane Library, Embase, Science Direct, Web of science, Scopus, and Google scholar were searched until November, 2023. Original publications of any type exploring the prognostic and therapeutic potential of lncRNAs in AML patients were included. Heterogeneity and publication bias were examined using the I2 test and a funnel plot, respectively. To quantify the relationship between various lncRNA expression in AML patient survival, odds ratios (ORs) or hazards ratios (HRs) with 95 % confidence intervals (CIs) were pooled. Quality of studies was assessed using the Critical Appraisal Checklists for Studies created by the Joanna Briggs Institute (JBI). ResultsTwenty-seven studies including 5665 subjects were selected for the final analysis. In patients with AML, abnormal lncRNA expression has been associated with significant worse overall survival (pooled HR = 2.05, 95 % CI = 1.79–2.30, P <0.001), shorter disease-free survival (pooled HR = 2.17, 95 % CI = 1.13–3.22, P< 0.001), and lower complete remission rate (pooled HR = 0.27, 95 % CI = 0.11–0.43, P< 0.001). Poor prognoses have been attributed to increased expression of HOX transcript antisense intergenic RNA (HOTAIR), Promoter Of CDKN1A Antisense DNA Damage Activated RNA (PANDAR), Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1), RP11–222K16.2, Taurine Upregulated Gene 1 (TUG1), Small Nucleolar RNA Host Gene 5 (SNHG5), Growth Arrest Specific 5 (GAS5), and H19 and decreased expression of IGF1R Antisense Imprinted Non-Protein Coding RNA (IRAIN). ConclusionThe prognoses of AML patients are significantly associated with abnormally expressed lncRNAs, which may be used as prognostic indicators for predicting the patient outcomes.

LncRNA MALAT-1 modulates EGFR-TKI resistance in lung adenocarcinoma cells by downregulating miR-125

Molecular targeted therapy resistance remains a major challenge in treating lung adenocarcinoma (LUAD). The resistance of Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs, epidermal growth factor receptor-tyrosine kinase inhibitor) plays a dominant role in molecular targeted therapy. Our previous research demonstrated the role of MALAT-1 (Metastasis-associated lung adenocarcinoma transcript 1) in the formation of Erlotinib-resistant LUAD cells. This study aims to uncover the mechanism of MALAT-1 overexpression in Erlotinib-resistant LUAD cells. The RT2 LncRNA PCR array system was used to explore MALAT-1 regulation in Erlotinib-resistant LUAD cells through patient serum analysis. Dual luciferase reporter experiments confirmed the binding between MALAT-1 and miR-125, leading to regulation of miR-125 expression. Functional assays were performed to elucidate the impact of MALAT1 on modulating drug resistance, growth, and Epithelial-mesenchymal transition (EMT, Epithelial-mesenchymal transition) in both parental and Erlotinib-resistant LUAD cells. The investigation unveiled the mechanism underlying the competing endogenous RNA (ceRNA, competing endogenouse RNA) pathway. MALAT1 exerted its regulatory effect on miR-125 as a competing endogenous RNA (ceRNA). Moreover, MALAT1 played a role in modulating the sensitivity of LUAD cells to Erlotinib. Rab25 was identified as the direct target of miR-125 and mediated the functional effects of MALAT1 in Erlotinib-resistant LUAD cells. In conclusion, our study reveals overexpress MALAT-1 cause the drug resistance of EGFR-TKIs in non-small cell lung cancer (NSCLC) through the MALAT-1/miR-125/Rab25 axis. These findings present a potential novel therapeutic target and perspective for the treatment of LUAD.

LncRNA TUG1 transcript levels and psychological disorders: insights into interplay of glycemic index and glycemic load

BackgroundThere is an association between obesity and psychological disorders such as depression, anxiety, and stress. Environmental factors and genetics play a crucial role in this regard. Several long non-coding RNAs (lncRNAs) are involved in the pathophysiology of the nervous system. Additionally, we intend to investigate how dietary glycemic index and load relate to psychological disorders in women with obesity and overweight by identifying the possible interaction with metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and taurine upregulated gene 1 (TUG1).Methods267 overweight or obese women between the ages of 18 and 48 were recruited for the current study. A reliable and validated food frequency questionnaire (FFQ) consisting of 147 items assessed food consumption, glycemic load (GL), and glycemic index (GI). Depression-Anxiety-Stress Scales (DASS-21) were used to assess mental well-being. A real-time polymerase chain reaction (PCR) was used to assess transcript levels for lncRNAs MALAT1 and TUG1.ResultsIn obese and overweight women, a positive correlation was found between anxiety and MALAT1 mRNA levels (P = 0.007, CC = 0.178). Age, energy intake, physical activity, total fat, income, marriage, thyroid, and BMI were adjusted, and GI and TUG1 were positively correlated on DASS-21 (β = 0.006, CI = 0.001, 0.01, P = 0.031), depression (β = 0.002, CI = 0.001, 0.004, P = 0.019), Stress (β = 0.003, CI = 0.001, 0.005, P = 0.027). The interaction of GL and TUG1 on stress was also observed (β = 0.03, CI = 0.001, 0.07, P = 0.048).ConclusionsThe lncRNA TUG1 appears to be associated with depression and stress through interaction with GI and correlated with stress by interaction with GL. To establish this concept, further research is required.

LncRNA MALAT1 Knockdown Alleviates Fibrogenic Response in Human Endometrial Stromal Cells Via the miR-22-3p/TGFβR1/Smad2/3 Pathway.

Intrauterine adhesion (IUA) resulting from irreversible fibrotic repair of endometrium is the main cause of secondary infertility in women, and current therapeutic approaches to IUA are limited. Increasing evidence has suggested the important role of competitive endogenous RNA (ceRNA) in IUA pathologies. This study aimed to investigate the long noncoding RNA (lncRNA) metastasis associated lung adenocarcinoma transcript 1 (MALAT1)-associated ceRNA in IUA development. We harvested endometrial tissues from patients with or without IUA and extracted endometrial stromal cells (ESCs) from normal endometrial tissues. Transforming growth factor β1 (TGF-β1) was used to induce fibrosis in ESCs. The expression of transforming growth factor β receptor 1 (TGFβR1), α-smooth muscle actin, phosphorylated suppressor of mother against decapentaplegic (p-Smad)2/3, collagen type I alpha 1, MALAT1, and microRNA (miR)-22-3p in endometrial tissues and ESCs was measured by reverse transcription quantitative polymerase chain reaction (RT-qPCR) or western blotting. Pearson's correlation analysis was conducted to assess the correlation between miR-22-3p expression or TGFβR1 and MALAT1 expression in endometrial tissues. The expression of TGFβR1 in ESCs was also evaluated by immunofluorescence staining. The location of MALAT1 was examined by fluorescence in situ hybridization. Luciferase reporter assays were performed to verify the binding relationship between MALAT1 or TGFβR1 and miR-22-3p. Cell viability was assessed via cell counting kit-8 assays. Our findings revealed that lncRNA MALAT1 and TGFβR1 were upregulated while miR-22-3p was downregulated in IUA endometrial tissues or TGF-β1-stimulated ESCs, and lncRNA MALAT1 expression was negatively correlated with miR-22-3p expression while being positively correlated with TGFβR1 expression in IUA endometrial tissues. Additionally, lncRNA MALAT1 was mainly located in the cytoplasm of ESCs and directly targeted miR-22-3p to regulate TGFβR1 expression. Moreover, knockdown of lncRNA MALAT1 exerted anti-fibrotic effects on ESCs by targeting miR-22-3p, and miR-22-3p overexpression inhibited the fibrosis of ESCs by binding to TGFβR1 3'untranslated region. Collectively, lncRNA MALAT1 promotes endometrial fibrosis by sponging miR-22-3p to regulate TGFβR1 and Smad2/3, and inhibition of MALAT1 may represent a promising therapeutic option for suppressing endometrial fibrosis.

Long noncoding RNA MALAT1 as a ceRNA drives mouse fibroblast activation via the miR-335-3p/P2ry2 axis.

Fibrosis is a complex pathological process that can lead to the permanent loss of biological function, with P2ry2 playing a crucial role in this process. Long non-coding RNAs (lncRNAs) have been reported to play an critically important role in the fibrotic process. However, it remains unclear whether lncRNAs can regulate fibrosis through P2ry2. In this study, we detected the expression of the long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (lnc-MALAT1). We investigated the expression patterns of lnc-MALAT1 and P2ry2 in denervated skeletal muscle, a classical model of fibrosis. Additionally, we utilized a TGF-β-mediated fibrosis model in NIH/3T3 cells to examine the effects of lnc-MALAT1 and P2ry2 on fibroblast activation and the underlying regulatory mechanisms in vitro. Our results demonstrated that the expression levels of lnc-MALAT1 and P2ry2 were consistently elevated in denervated skeletal muscle, correlating with the degree of fibrosis. In vitro experiments confirmed the regulatory effect of lnc-MALAT1 on P2ry2. Furthermore, we identified miR-335-3p as a potential key molecule in the regulatory relationship of lnc-MALAT1/P2ry2. Dual luciferase reporter assays and AGO2-RIP verified the molecular sponging effect of lnc-MALAT1 on miR-335-3p. Additionally, we validated the regulation of the lnc-MALAT1/miR-335-3p/P2ry2 axis through experimental approaches. In conclusion, our study identified a crucial role of lnc-MALAT1/miR-335-3p/P2ry2 axis in fibroblast activation, providing a promising treatment option against the fibrosis.

The Role of MALAT1 in Regulating the Proangiogenic Functions, Invasion, and Migration of Trophoblasts in Selective Fetal Growth Restriction.

Epigenetic regulation is an important entry point to study the pathogenesis of selective fetal growth restriction (sFGR), and an understanding of the role of long noncoding RNAs (lncRNAs) in sFGR is lacking. Our study aimed to investigate the potential role of a lncRNA, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), in sFGR using molecular biology experiments and gain- or loss-of-function assays. We found that the levels of MALAT1, ERRγ, and HSD17B1 were downregulated and that of miR-424 was upregulated in the placental shares of the smaller twins. Moreover, angiogenesis was impaired in the placental share of the smaller fetus and MALAT1 could regulate the paracrine effects of trophoblasts on endothelium angiogenesis and proliferation by regulating miR-424. In trophoblasts, MALAT1 could competitively bind to miR-424 to regulate the expression of ERRγ and HSD17B1, thus regulating trophoblast invasion and migration. MALAT1 overexpression could decrease apoptosis and promote proliferation, alleviating cell damage induced by hypoxia. Taken together, the downregulation of MALAT1 can reduce the expression of ERRγ and HSD17B1 by competitively binding to miR-424, impairing the proangiogenic effect of trophoblasts, trophoblast invasion and migration, and the ability of trophoblasts to compensate for hypoxia, which may be involved in the pathogenesis of sFGR through various aspects.

Unveiling the role of long non-coding RNA MALAT1: a comprehensive review on myocardial infarction.

Myocardial infarction (MI) stands at top global causes of death in developed countries, owing mostly to atherosclerotic plaque growth and endothelial injury-induced reduction in coronary blood flow. While early reperfusion techniques have improved outcomes, long-term treatment continues to be difficult. The function of lncRNAs extends to regulating gene expression in various conditions, both physiological and pathological, such as cardiovascular diseases. The objective of this research is to extensively evaluate the significance of the lncRNA called Metastasis associated lung adenocarcinoma transcript 1 (MALAT1) in the development and management of MI. According to research, MALAT1 is implicated in processes such as autophagy, apoptosis, cell proliferation, and inflammation in the cardiovascular system. This investigation examines recent research examining the effects of MALAT1 on heart function and its potential as a mean of diagnosis and treatment for post- MI complications and ischemic reperfusion injury.

In-Silico and In-Vitro Investigation of Key Long Non-coding RNAs Involved in 5-Fluorouracil Resistance in Colorectal Cancer Cells: Analyses Highlighting NEAT1 and MALAT1 as Contributors.

Background Acquired resistance to 5-fluorouracil (5-FU) frequently results in chemotherapy failure and disease recurrence in advanced colorectal cancer (CRC) patients. Research has demonstrated that dysregulation of long non-coding RNAs (lncRNAs) mediates the development of chemotherapy resistance in cancerous cells. The present study aims to identify key lncRNAs associated with 5-FU resistance in CRC using bioinformatic and experimental validation approaches. Methods The Gene Expression Omnibus (GEO) dataset GSE119481, which contains miRNA expression profiles of the parental CRC HCT116 cell line (HCT116/P) and its in-vitro established 5-FU-resistant sub-cell line (HCT116/FUR), was downloaded. Firstly, differentially expressed microRNAs (DEmiRNAs) between the parental and 5-FU resistance cells were identified. LncRNAs and mRNAs were then predicted using online databases. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to uncover relevant biological mechanisms and pathways. Networks integrating lncRNAs, miRNAs, and mRNAs interactions were constructed, and topological analyses were used to identify key lncRNAs associated with 5-FU resistance. An in-vitro model of the HCT116/FUR sub-cell line was developed by exposing the HCT116/P cell line to increasing concentrations of 5-FU. Finally, real-time quantitative PCR (RT-qPCR) was performed on total RNA extracted from the HCT116/P cell line and the HCT116/FUR sub-cell line to validate the in-silico predictions of key lncRNAs. Results A total of 32 DEmiRNAs were identified. Enrichment analysis demonstrated that these DEmiRNAs were mainly enriched in several cancer hallmark pathways that regulate cell growth, cell cycle, cell survival, inflammation, immune response, and apoptosis. The predictive analysis identified 237 unique lncRNAs and 123 mRNAs interacting with these DEmiRNAs. The pathway analysis indicated that most of these predicted genes were enriched in the cellular response to starvation, protein polyubiquitination, chromatin remodeling, and negative regulation of gene expression. Topological analyses of the lncRNA-miRNA-mRNA network highlighted the nuclear enriched abundant transcript 1 (NEAT1), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), and Opa interacting protein 5 antisense RNA 1 (OIP5-AS1) as central lncRNAs. Experimental analysis by RT-qPCR confirmed that the expression levels of NEAT1 and MALAT1 were significantly increased in HCT116/FUR cells compared to HCT116/P cells. However, no significant difference was observed in the OIP5-AS1 expression level between the two cells. Conclusion Our findings specifically highlight MALAT1 and NEAT1 as significant contributors to 5-FU resistance in CRC. These lncRNAs are promising biomarkers for diagnosing and predicting outcomes in CRC.