Up-regulation of long noncoding RNA MALAT1 contributes to proliferation and metastasis in esophageal squamous cell carcinoma

Gene expression profiling of lncRNA-HOTAIR and lncRNA-MALAT1 in esophageal cancer: uncovering links to lifestyle factors and diagnostic significance

BACKGROUND

Esophageal cancer (EC) is the sixth most common cause of cancer-related deaths globally. Genetic and environmental factors could be affected in EC's onset and development. The potential involvement of lncRNA-HOTAIR and lncRNA-MALAT1 in EC has garnered significant attention in recent studies. Our investigation aimed to examine lncRNA-HOTAIR and lncRNA-MALAT1 gene expression changes in EC patients.

MATERIALS AND METHODS

Our experimental study focused on 140 patients with malignant EC, comprising 70 paraffin-embedded tumor tissues (FFPE) blocks and 70 FFPE blocks with marginal tissue samples. The relative gene expression levels of lncRNA-HOTAIR and lncRNA-MALAT1 were measured using Real-Time PCR. The data were analyzed using ANOVA and 2-△△CT tests.

RESULTS

Our analysis revealed a significant increase in tumor expression compared to marginal tissues (P < 0.05). Besides, our research revealed a significant correlation between lncRNA-HOTAIR expression and hot drinks (P = 0.019), metastasis (P = 0.001), and the 5-year survival rate (P = 0.001). We found a significant correlation between lncRNA-MALAT1 expression and alcohol abuse (P = 0.039), hot drinks (P = 0.001), and metastasis (P = 0.039).

CONCLUSION

The findings indicate a potential carcinogenic effect of lncRNA-HOTAIR and lncRNA-MALAT1 gene expression alterations in EC patients. Also, studying the lncRNA genes can help us identify biomarkers, emphasizing the significance of early diagnosis and treatment.

Long non-coding RNAs as therapeutic targets in head and neck squamous cell carcinoma and clinical application

Head and neck squamous cell carcinoma (HNSCC) is a major global health burden, often associated with poor prognosis and limited therapeutic options. Long non-coding RNAs (lncRNAs), a diverse group of non-coding RNA molecules > 200 nucleotides in length, have emerged as critical regulators in the pathogenesis of HNSCC. This review summarizes the mechanisms through which certain lncRNAs regulate chromatin modification, mRNA splicing, and interactions with RNA-binding proteins and contribute to the development and progression of HNSCC. Interaction of lncRNAs with key oncogenic pathways, such as PI3K/AKT and Wnt/β-catenin, highlights their importance in tumor progression. The role of lncRNAs, such as ELDR, MALAT1, NEAT1, HOTAIR, and UCA1, which promote cell proliferation, metastasis, immune evasion, and therapy resistance is discussed. Moreover, several lncRNAs are being evaluated in clinical trials for their potential as biomarkers, reflecting their clinical significance. We further address the challenges and opportunities for targeting lncRNA therapeutically, highlighting the promise of lncRNA-based interventions for personalized cancer treatment. Gaining insight into the function of lncRNAs in HNSCC could pave the way for novel therapeutic strategies to potentially improve patient outcomes.

Inhibition of the long non-coding RNA MALAT1 downregulates MAP2K1, suppressing the progression of hypopharyngeal squamous cell carcinoma

This study aimed to explore the role of long non-coding RNAs metastasis-associated lung adenocarcinoma transcript (lncRNA MALAT1), 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 parallel reaction monitoring (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 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.

TCF12 and LncRNA MALAT1 Cooperatively Harness High Cyclin D1 but Low β-Catenin Gene Expression to Exacerbate Colorectal Cancer Prognosis Independently of Metastasis

Metastasis is a well-known factor worsening colorectal cancer (CRC) prognosis, but mortality mechanisms in non-metastatic patients with poor outcomes are less understood. TCF12 is a transcription factor that can be physically associated with the long non-coding RNA MALAT1, creating an alliance with correlated expression levels in CRC patients. This TCF12-MALAT1 alliance is linked to poorer prognosis independently of age and metastasis. To identify the downstream effects responsible for this outcome, we analyzed 2312 common target genes of TCF12 and MALAT1, finding involvement in pathways like Aurora B, ATM, PLK1, and non-canonical WNT. We investigated the impact of WNT downstream genes CTNNB1 and CCND1, encoding β-catenin and cyclin D1, respectively, on survival in CRC patients with this alliance. Tumors with higher TCF12 and MALAT1 gene expressions alongside increased β-catenin gene expressions were classified as having a "Pan-CMS-2 pattern", showing relatively better prognoses. Conversely, tumors with high TCF12, MALAT1, and cyclin D1 gene expressions but low β-catenin expression were categorized as "TMBC pattern", associated with poor survival, with survival rates dropping sharply from 60% at one year to 30% at three years. This suggests that targeting cyclin D1-associated CDK4/6 could potentially reduce early mortality risks in TMBC patients, supporting personalized medicine approaches.

Schistosoma japonicum infection-mediated downregulation of lncRNA Malat1 contributes to schistosomiasis hepatic fibrosis by the Malat1/miR-96/Smad7 pathway

BACKGROUND

Schistosoma japonicum infection causes hepatic fibrosis, a primary cause of morbidity and mortality associated with the disease, and effective treatments are still lacking. Long non-coding RNAs (lncRNAs) have been implicated in the pathogenic process of various tissue fibroses. However, the role of lncRNAs in schistosomiasis hepatic fibrosis (HF) is poorly understood. Understanding the role of lncRNAs in schistosomiasis HF will enhance knowledge of disease processes and aid in the discovery of therapeutic targets and diagnostic biomarkers.

METHODS

Differentially expressed lncRNA profiles in primary hepatic stellate cells (HSCs) of mice infected with S. japonicum were identified using high-throughput lncRNA sequencing. Primary HSCs were isolated from infected mice using collagenase digestion and density-gradient centrifugation, cultured in DMEM with 10% fetal bovine serum. Dual-luciferase reporter assays, nuclear cytoplasm fractionation and RIP assays were employed to assess the relationship between Malat1 and miRNA-96. Malat1 lentivirus and ASO-Malat1 were constructed for forced expression and downregulated expression of Malat1. The Malat1-KO mouse was constructed by CRISPR/Cas9 technology. Pathological features of the liver were evaluated by hematoxylin-eosin (HE), Masson's trichrome staining and immunohistochemistry (IHC). The expression levels of fibrosis-related genes were determined by quantitative real-time PCR (qRT-PCR) and Western blot.

RESULTS

A total of 1561 differentially expressed lncRNAs were identified between infected and uninfected primary HSCs. Among the top altered lncRNAs, the downregulated Malat1 was observed in infected HSCs and verified by qPCR. Treatment of infected mice with praziquantel (PZQ) significantly increased the Malat1 expression. Elevated Malat1 expression in infected primary HSC reduced the expressions of profibrogenic genes, whereas Malat1 knockdown had the opposite effect. Moreover, Malat1 was found to interact with miR-96, a profibrotic miRNA, by targeting Smad7. Forced Malat1 expression reduced miR-96 levels in infected primary HSCs, attenuating fibrogenesis and showing negative correlation between Malat1 expression and the expression levels of miR-96 and profibrogenic genes α-SMA and Col1α1. Notably, in Malat1-KO mice, knockout of Malat1 aggravates schistosomiasis HF, while restored Malat1 expression in the infected HSCs reduced the expression of profibrogenic genes.

CONCLUSIONS

We demonstrate that lncRNA is involved in regulation of schistosomiasis HF. Elevated lncRNA Malat1 expression in infected HSCs reduces fibrosis via the Malat1/miR-96/Smad7 pathway, thus providing a novel therapeutic target for schistosomiasis HF. Furthermore, Malat1 expression is sensitive to PZQ treatment, thus offering a potential biomarker for assessing the response to chemotherapy.

Progress of Exosomal LncRNAs in Pancreatic Cancer

Pancreatic cancer is a prevalent malignant tumor with rising medication resistance and mortality. Due to a dearth of specific and trustworthy biomarkers and therapeutic targets, pancreatic cancer early detection and treatment are still not at their best. Exosomal LncRNAs have been found to be plentiful and persistent within exosomes, and they are capable of functioning whether the exosomes are traveling to close or distant cells. Furthermore, increasing evidence suggests that exosomal LncRNA, identified as an oncogene or tumor suppressor-control the growth, metastasis, and susceptibility of pancreatic cancer to chemotherapy and radiation therapy. Promising prospects for both antitumor targets and diagnostic biomarkers are exosomal LncRNAs. The primary features of exosomal LncRNAs, their biological roles in the onset and progression of pancreatic cancer, and their potential as therapeutic targets and diagnostic molecular markers are outlined in this review.

Unveiling potential: urinary exosomal mRNAs as non-invasive biomarkers for early prostate cancer diagnosis

BACKGROUND

This study investigated the use of urinary exosomal mRNA as a potential biomarker for the early detection of prostate cancer (PCa).

METHODS

Next-generation sequencing was utilized to analyze exosomal RNA from 10 individuals with confirmed PCa and 10 individuals without cancer. Subsequent validation through qRT-PCR in a larger sample of 43 PCa patients and 92 healthy controls revealed distinct mRNA signatures associated with PCa.

RESULTS

Notably, mRNAs for RAB5B, WWP1, HIST2H2BF, ZFY, MARK2, PASK, RBM10, and NRSN2 showed promise as diagnostic markers, with AUC values between 0.799 and 0.906 and significance p values. Combining RAB5B and WWP1 in an exoRNA diagnostic model outperformed traditional PSA tests, achieving an AUC of 0.923, 81.4% sensitivity, and 89.1% specificity.

CONCLUSIONS

These findings highlight the potential of urinary exosomal mRNA profiling, particularly focusing on RAB5B and WWP1, as a valuable strategy for improving the early detection of PCa.

CSPG4P12 polymorphism served as a susceptibility marker for esophageal cancer in Chinese population

BACKGROUND

Chondroitin sulfate proteoglycan 4 pseudogene 12 (CSPG4P12) has been implicated in the pathogenesis of various cancers. This study aimed to evaluate the association of the CSPG4P12 polymorphism with esophageal squamous cell carcinoma (ESCA) risk and to explore the biological impact of CSPG4P12 expression on ESCA cell behavior.

METHODS

A case-control study was conducted involving 480 ESCA patients and 480 healthy controls to assess the association between the rs8040855 polymorphism and ESCA risk. The CSPG4P12 rs8040855 genotype was identified using the TaqMan-MGB probe method. Logistic regression model was used to evaluate the association of CSPG4P12 SNP with the risk of ESCA by calculating the odds ratios (OR) and 95% confidence intervals (95%CI ). The effects of CSPG4P12 overexpression on cell proliferation, migration, and invasion were examined in ESCA cell lines. Co-expressed genes were identified via the CBioportal database, with pathway enrichment analyzed using SangerBox. The binding score of CSPG4P12 to P53 was calculated using RNA protein interaction prediction (RPISeq). Additionally, Western Blot analysis was performed to investigate the impact of CSPG4P12 overexpression on the P53/PI3K/AKT signaling pathway.

RESULTS

The presence of at least one rs8040855 G allele was associated with a reduced susceptibility to ESCA compared to the CC genotype (OR = 0.51, 95%CI = 0.28-0.93, P = 0.03). Stratification analysis revealed that the CSPG4P12 rs8040855 C allele significantly decreased the risk of ESCA among younger individuals (≤ 57 years) and non-drinkers (OR = 0.31, 95%CI = 0.12-0.77, P = 0.01; OR = 0.42, 95%CI=0.20-0.87, P = 0.02, respectively). CSPG4P12 expression was found to be downregulated in ESCA tissues compared to adjacent normal tissues. Overexpression of CSPG4P12 in ESCA cells inhibited their proliferation, migration, and invasion capabilities. Furthermore, Western Blot analysis indicated that CSPG4P12 overexpression led to a reduction in PI3K and p-AKT protein expression levels. P53 silencing rescues the inhibitory effect of CSPG4P12 on p-AKT.

CONCLUSION

The CSPG4P12 rs8040855 variant is associated with reduced ESCA risk and the overexpression of CSPG4P12 inhibited the migration and invasion of ESCA cells by P53/PI3K/AKT pathway. These findings suggest that CSPG4P12 may serve as a novel biomarker for ESCA susceptibility and a potential target for therapeutic intervention.

Puzzling out the role of MIAT LncRNA in hepatocellular carcinoma

A non-negligible part of our DNA has been proven to be transcribed into non-protein coding RNA and its intricate involvement in several physiological processes has been highly evidenced. The significant biological role of non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs) has been variously reported. In the current review, the authors highlight the multifaceted role of myocardial infarction-associated transcript (MIAT), a well-known lncRNA, in hepatocellular carcinoma (HCC). Since its discovery, MIAT has been described as a regulator of carcinogenesis in several malignant tumors and its overexpression predicts poor prognosis in most of them. At the molecular level, MIAT is closely linked to the initiation of metastasis, invasion, cellular migration, and proliferation, as evidenced by several in-vitro and in-vivo models. Thus, MIAT is considered a possible theranostic agent and therapeutic target in several malignancies. In this review, the authors provide a comprehensive overview of the underlying molecular mechanisms of MIAT in terms of its downstream target genes, interaction with other classes of ncRNAs, and potential clinical implications as a diagnostic and/or prognostic biomarker in HCC.

Exosomal MALAT1 promotes the proliferation of esophageal squamous cell carcinoma through glyoxalase 1-dependent methylglyoxal removal

In previous study we characterized the oncogenic role of long non-coding RNA MALAT1 in esophageal squamous cell carcinoma (ESCC), but the detailed mechanism remains obscure. Here we identified glyoxalase 1 (GLO1) as the most possible executor of MALAT1 by microarray screening. GLO1 is responsible for degradation of cytotoxic methylglyoxal (MGO), which is by-product of tumor glycolysis. Accumulated MGO may lead to glycation of DNA and protein, resulting in elevated advanced glycation end products (AGEs), while glyoxalase 1 detoxify MGO to alleviate its cytotoxic effect to tumor cells. GLO1 interfering led to accumulation of AGEs and following activation of DNA injury biomarkers, which lead to cell cycle arrest and growth inhibition. In silico analysis based on online database revealed abundant enrichment of histone acetylation marker H3K27ac in GLO1 promotor, and acetyltransferase inhibitor C646 declined GLO1 expression. Acetyltransferase KAT2B, which was also identified as a target of MALAT, mediated histone lysine acetylation of GLO1 promotor, which was confirmed by ChIP-qPCR experiment. Shared binding sites of miR-206 were found on MALAT1 and KAT2B mRNA. Dual-luciferase reporter assays confirmed interaction within MALAT1-miR-206-GLO1. Finally, we identified MALAT1 encapsuled by exosome from donor cells, and transferred malignant behaviors to recipient cells. The secreted exosomes may enter circulation, and serum MALAT1 level combined with traditional tumor markers showed potential power for ESCC diagnosis.

MALAT1: A Long Non-Coding RNA with Multiple Functions and Its Role in Processes Associated with Fat Deposition

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) belongs to the lncRNA molecules, which are involved in transcriptional and epigenetic regulation and the control of gene expression, including the mechanism of chromatin remodeling. MALAT1 was first discovered during carcinogenesis in lung adenocarcinoma, hence its name. In humans, 66 of its isoforms have been identified, and in pigs, only 2 are predicted, for which information is available in Ensembl databases (Ensembl Release 111). MALAT1 is expressed in numerous tissues, including adipose, adrenal gland, heart, kidney, liver, ovary, pancreas, sigmoid colon, small intestine, spleen, and testis. MALAT1, as an lncRNA, shows a wide range of functions. It is involved in the regulation of the cell cycle, where it has pro-proliferative effects and high cellular levels during the G1/S and mitotic (M) phases. Moreover, it is involved in invasion, metastasis, and angiogenesis, and it has a crucial function in alternative splicing during carcinogenesis. In addition, MALAT1 plays a significant role in the processes of fat deposition and adipogenesis. The human adipose tissue stem cells, during differentiation into adipocytes, secrete MALAT1 as one the most abundant lncRNAs in the exosomes. MALAT1 expression in fat tissue is positively correlated with adipogenic FABP4 and LPL. This lncRNA is involved in the regulation of PPARγ at the transcription stage, fatty acid metabolism, and insulin signaling. The wide range of MALAT1 functions makes it an interesting target in studies searching for drugs to prevent obesity development in humans. In turn, in farm animals, it can be a source of selection markers to control the fat tissue content.

LncRNA LUESCC promotes esophageal squamous cell carcinoma by targeting the miR-6785-5p/NRSN2 axis

Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent gastrointestinal malignancies with high mortality worldwide. Emerging evidence indicates that long noncoding RNAs (lncRNAs) are involved in human cancers, including ESCC. However, the detailed mechanisms of lncRNAs in the regulation of ESCC progression remain incompletely understood. LUESCC was upregulated in ESCC tissues compared with adjacent normal tissues, which was associated with gender, deep invasion, lymph node metastasis, and poor prognosis of ESCC patients. LUESCC was mainly localized in the cytoplasm of ESCC cells. Knockdown of LUESCC inhibited cell proliferation, colony formation, migration, and invasion in vitro and suppressed tumor growth in vivo. Mechanistic investigation indicated that LUESCC functions as a ceRNA by sponging miR-6785-5p to enhance NRSN2 expression, which is critical for the malignant behaviors of ESCC. Furthermore, ASO targeting LUESCC substantially suppressed ESCC both in vitro and in vivo. Collectively, these data demonstrate that LUESCC may exerts its oncogenic role by sponging miR-6785-5p to promote NRSN2 expression in ESCC, providing a potential diagnostic marker and therapeutic target for ESCC patients.

Role of long non-coding RNAs in cholangiocarcinoma: A systematic review and meta-analysis

BACKGROUND

Cholangiocarcinoma (CCA), as a rare malignancy of the biliary tree, has a poor prognosis most of the time. CCA is highly epigenetically regulated and several long non-coding RNAs (lncRNA) have been investigated to have a diagnostic and prognostic role in CCA. The current study aimed to assess the studies finding relevant lncRNAs in CCA systematically.

METHODS

International databases, including PubMed, Cochrane Library, and Embase, were comprehensively searched in order to identify studies investigating any lncRNA in CCA. After screening by title/abstract and full-text, necessary data were extracted. Random-effect meta-analysis was performed for pooling the areas under the curve (AUCs), specificity, and sensitivity of lncRNAs for the diagnosis of CCA.

RESULTS

A total of 33 studies were chosen to be included in the final analysis, comprised of 2677 patients. Meta-analysis of AUCs for evaluation of CCA resulted in pooled AUC of 0.79 (95% CI: 0.75-0.82; I2 = 69.11, p < .01). Additionally, overall sensitivity of 0.80 (95% CI 0.75-0.84) and specificity of 0.77 (95% CI: 0.68-0.84) were observed. Measurement of lncRANs in the assessment of CCA also improved overall survival significantly (effect size 1.61, 95% CI: 1.39-1.82). A similar result was found for progression-free survival (effect size 1.57, 95% CI: 1.20-1.93).

CONCLUSION

Based on our findings, lncRNAs showed promising results as biomarkers in the diagnosis of CCA since they had acceptable sensitivity and specificity, in addition to the fact that improved survival in this poor prognosis cancer. Further studies might be needed to address this issue and find the best clinically useful lncRNA.

A comprehensive database of exosome molecular biomarkers and disease-gene associations

Exosomes play a crucial role in intercellular communication and can be used as biomarkers for diagnostic and therapeutic clinical applications. However, systematic studies in cancer-associated exosomal nucleic acids remain a big challenge. Here, we developed ExMdb, a comprehensive database of exosomal nucleic acid biomarkers and disease-gene associations curated from published literature and high-throughput datasets. We performed a comprehensive curation of exosome properties including 4,586 experimentally supported gene-disease associations, 13,768 diagnostic and therapeutic biomarkers, and 312,049 nucleic acid subcellular locations. To characterize expression variation of exosomal molecules and identify causal factors of complex diseases, we have also collected 164 high-throughput datasets, including bulk and single-cell RNA sequencing (scRNA-seq) data. Based on these datasets, we performed various bioinformatics and statistical analyses to support our conclusions and advance our knowledge of exosome biology. Collectively, our dataset will serve as an essential resource for investigating the regulatory mechanisms of complex diseases and improving the development of diagnostic and therapeutic biomarkers.

MALAT-1 Is a Key Regulator of Epithelial-Mesenchymal Transition in Cancer: A Potential Therapeutic Target for Metastasis

Metastasis-associated lung adenocarcinoma transcript-1 (MALAT-1) is a long intergenic non-coding RNA (lncRNA) located on chr11q13. It is overexpressed in several cancers and controls gene expression through chromatin modification, transcriptional regulation, and post-transcriptional regulation. Importantly, MALAT-1 stimulates cell proliferation, migration, and metastasis and serves a vital role in driving the epithelial-to-mesenchymal transition (EMT), subsequently acquiring cancer stem cell-like properties and developing drug resistance. MALAT-1 modulates EMT by interacting with various intracellular signaling pathways, notably the phosphoinositide 3-kinase (PI3K)/Akt and Wnt/β-catenin pathways. It also behaves like a sponge for microRNAs, preventing their interaction with target genes and promoting EMT. In addition, we have used bioinformatics online tools to highlight the disparities in the expression of MALAT-1 between normal and cancer samples using data from The Cancer Genome Atlas (TCGA). Furthermore, the intricate interplay of MALAT-1 with several essential targets of cancer progression and metastasis renders it a good candidate for therapeutic interventions. Several innovative approaches have been exploited to target MALAT-1, such as short hairpin RNAs (shRNAs), antisense oligonucleotides (ASOs), and natural products. This review emphasizes the interplay between MALAT-1 and EMT in modulating cancer metastasis, stemness, and chemoresistance in different cancers.

Single Nucleotide Polymorphisms (SNPs) in the Shadows: Uncovering their Function in Non-Coding Region of Esophageal Cancer

Esophageal cancer is a complex disease influenced by genetic and environmental factors. Single nucleotide polymorphisms (SNPs) in non-coding regions of the genome have emerged as crucial contributors to esophageal cancer susceptibility. This review provides a comprehensive overview of the role of SNPs in non-coding regions and their association with esophageal cancer. The accumulation of SNPs in the genome has been implicated in esophageal cancer risk. Various studies have identified specific locations in the genome where SNPs are more likely to occur, suggesting a location-specific response. Chromatin conformational studies have shed light on the localization of SNPs and their impact on gene transcription, posttranscriptional modifications, gene expression regulation, and histone modification. Furthermore, miRNA-related SNPs have been found to play a significant role in esophageal squamous cell carcinoma (ESCC). These SNPs can affect miRNA binding sites, thereby altering target gene regulation and contributing to ESCC development. Additionally, the risk of ESCC has been linked to base excision repair, suggesting that SNPs in this pathway may influence disease susceptibility. Somatic DNA segment alterations and modified expression quantitative trait loci (eQTL) have also been associated with ESCC. These alterations can lead to disrupted gene expression and cellular processes, ultimately contributing to cancer development and progression. Moreover, SNPs have been found to be associated with the long non-coding RNA HOTAIR, which plays a crucial role in ESCC pathogenesis. This review concludes with a discussion of the current and future perspectives in the field of SNPs in non-coding regions and their relevance to esophageal cancer. Understanding the functional implications of these SNPs may lead to the identification of novel therapeutic targets and the development of personalized approaches for esophageal cancer prevention and treatment.

LncRNA MALAT1 signaling pathway and clinical applications in overcome on cancers metastasis

In spite of its high mortality rate and difficulty in finding a cure, scientific advancements have contributed to a reduction in cancer-related fatalities. Aberrant gene expression during carcinogenesis emphasizes the importance of targeting the signaling networks that control gene expression in cancer treatment. Long noncoding RNAs (lncRNAs), which are transcribed RNA molecules that play a role in gene expression regulation, are a recent innovative therapeutic approach for diagnosing and treating malignancies. MALAT1, a well-known lncRNA, functions in gene expression, RNA processing, and epigenetic control. High expression levels of MALAT1 are associated with several human disorders, including metastasis, invasion, autophagy, and proliferation of cancer cells. MALAT1 affects various signaling pathways and microRNAs (miRNAs), and this study aims to outline its functional roles in cancer metastasis and its interactions with cellular signaling pathways. Moreover, MALAT1 and its interactions with signaling pathways can be promising target for cancer treatment.

BZW2 Inhibition Reduces Colorectal Cancer Growth and Metastasis

Because survival of patients with metastatic colorectal cancer remain poor, there is an urgent need to identify potential novel druggable targets that are associated with colorectal cancer progression. One such target, basic leucine zipper and W2 domains 2 (BZW2), is involved in regulation of protein translation, and its overexpression is associated with human malignancy. Thus, we investigated the expression and regulation of BZW2, assessed its role in activation of WNT/β-catenin signaling, identified its downstream molecules, and demonstrated its involvement in metastasis of colorectal cancer. In human colorectal cancers, high mRNA and protein expression levels of BZW2 were associated with tumor progression. BZW2-knockdown reduced malignant phenotypes, including cell proliferation, invasion, and spheroid and colony formation. BZW2-knockdown also reduced tumor growth and metastasis; conversely, transfection of BZW2 into BZW2 low-expressing colorectal cancer cells promoted malignant features, including tumor growth and metastasis. BZW2 expression was coordinately regulated by microRNA-98, c-Myc, and histone methyltransferase enhancer of zeste homolog 2 (EZH2). RNA sequencing analyses of colorectal cancer cells modulated for BZW2 identified P4HA1 and the long noncoding RNAs, MALAT1 and NEAT1, as its downstream targets. Further, BZW2 activated the Wnt/β-catenin signaling pathway in colorectal cancers expressing wild-type β-catenin. In sum, our study suggests the possibility of targeting BZW2 expression by inhibiting EZH2 and/or c-Myc.

IMPLICATIONS

FDA-approved small-molecule inhibitors of EZH2 can indirectly target BZW2 and because BZW2 functions as an oncogene, these inhibitors could serve as therapeutic agents for colorectal cancer.

The MALAT1-breast cancer interplay: insights and implications

INTRODUCTION

Breast cancer (BC) is a major public health concern, and identifying new biomarkers and therapeutic targets is critical to improving patient outcomes. MALAT1, a long noncoding RNA, has emerged as a promising candidate due to its overexpression in BC and the associated poor prognosis. Understanding the role of MALAT1 in BC progression is paramount for the development of effective therapeutic strategies.

COVERED AREA

This review delves into the structure and function of MALAT1, and examines its expression pattern in breast cancer (BC) and its association with different BC subtypes. This review focuses on the interactions between MALAT1 and microRNAs (miRNAs) and the various signaling pathways involved in BC. Furthermore, this study investigates the influence of MALAT1 on the BC tumor microenvironment and the possible influence of MALAT1 on immune checkpoint regulation. This study also sheds light the role of MALAT1 in breast cancer resistance.

EXPERT OPINION

MALAT1 has been shown to play a key role in the progression of BC, highlighting its importance as a potential therapeutic target. Further studies are needed to elucidate the underlying molecular mechanisms by which MALAT1 contributes to the development of BC. In combination with standard therapy, there is a need to evaluates the potential of treatments targeting MALAT1, which may lead to improved treatment outcomes. Moreover, study of MALAT1 as a diagnostic and prognostic marker promises improved BC management. Continued efforts to decipher the functional role of MALAT1 and explore its clinical utility are critical to advancing the BC research field.

Splicing factor TRA2A contributes to esophageal cancer progression via a noncanonical role in lncRNA m6 A methylation

Transformer 2 alpha homolog (TRA2A), a member of the serine/arginine-rich splicing factor family, has been shown to control mRNA splicing in development and cancers. However, it remains unclear whether TRA2A is involved in lncRNA regulation. In the present study, we found that TRA2A was upregulated and correlated with poor prognosis in esophageal cancer. Downregulation of TRA2A suppressed the tumor growth in xenograft nude mice. Epitranscriptomic microarray showed that depletion of TRA2A affected global lncRNA methylation similarly to the key m⁶ A methyltransferase, METTL3, by silencing. MeRIP-qPCR, RNA pull-down, CLIP analyses, and stability assays indicated that ablation of TRA2A reduced m⁶ A-modification of the oncogenic lncRNA MALAT1, thus inducing structural alterations and reduced stability. Furthermore, Co-IP experiments showed TRA2A directly interacted with METTL3 and RBMX, which also affected the writer KIAA1429 expression. Knockdown of TRA2A inhibited cell proliferation in a manner restored by RBMX/KIAA1429 overexpression. Clinically, MALAT1, RBMX, and KIAA1429 were prognostic factors of worse survival in ESCA patients. Structural similarity-based virtual screening in FDA-approved drugs repurposed nebivolol, a β₁ -adrenergic receptor antagonist, as a potent compound to suppress the proliferation of esophageal cancer cells. Cellular thermal shift and RIP assay indicated that nebivolol may compete with MALAT1 to bind TRA2A. In conclusion, our study revealed the noncanonical function of TRA2A, which coordinates with multiple methylation proteins to promote oncogenic MALAT1 during ESCA carcinogenesis.

Key events in cancer: Dysregulation of SREBPs

Lipid metabolism reprogramming is an important hallmark of tumor progression. Cancer cells require high levels of lipid synthesis and uptake not only to support their continued replication, invasion, metastasis, and survival but also to participate in the formation of biological membranes and signaling molecules. Sterol regulatory element binding proteins (SREBPs) are core transcription factors that control lipid metabolism and the expression of important genes for lipid synthesis and uptake. A growing number of studies have shown that SREBPs are significantly upregulated in human cancers and serve as intermediaries providing a mechanistic link between lipid metabolism reprogramming and malignancy. Different subcellular localizations, including endoplasmic reticulum, Golgi, and nucleus, play an indispensable role in regulating the cleavage maturation and activity of SREBPs. In this review, we focus on the relationship between aberrant regulation of SREBPs activity in three organelles and tumor progression. Because blocking the regulation of lipid synthesis by SREBPs has gradually become an important part of tumor therapy, this review also summarizes and analyzes several current mainstream strategies.

LINC00707 Promotes Cell Proliferation in Cervical Cancer via the miR-374c-5p/SDC4 Axis

Cervical cancer (CC) is the second main reason of cancer-related deaths in women around the world. Long intergenic nonprotein coding RNA 707, which is known as LINC00707, has been elucidated to facilitate the progression of multifarious tumors, but how it may exert functions in CC has not been elucidated yet. By using quantitative real-time RT-PCR (RT-qPCR), we identified the expression pattern LINC00707 may possess in CC. Loss-of-function assays including Cell Counting Kit-8 (CCK-8), colony formation, and transferase-mediated dUTP nick-end labeling (TUNEL) assays were taken to verify the effects of LINC00707 inhibition on CC cell proliferation and apoptosis. The downstream RNAs were selected through bioinformatics prediction, and their interaction with LINC00707 was verified through mechanism assays including the luciferase reporter assay, RNA pull-down assay, and RNA immunoprecipitation (RIP) assay. According to results, LINC00707 was upregulated in CC cells, and LINC00707 insufficiency inhibited cell proliferation while facilitating cell apoptosis. MicroRNA (miRNA) miR-374c-5p interacted with LINC00707, and syndecan-4 (SDC4) was verified to be the downstream target gene. Data of rescue assays proved that LINC00707 could promote CC cell malignancy via the miR-374c-5p/SDC4 axis, which revealed a potential treatment option for CC.

The Emerging Role of Long Non-Coding RNAs in Esophageal Cancer: Functions in Tumorigenesis and Clinical Implications

Esophageal cancer (EC) is one of the most common malignancies of digestive tracts with poor five-year survival rate. Hence, it is very significant to further investigate the occurrence and development mechanism of esophageal cancer, find more effective biomarkers and promote early diagnosis and effective treatment. Long non-coding RNAs (lncRNAs) are generally defined as non-protein-coding RNAs with more than 200 nucleotides in length. Existing researches have shown that lncRNAs could act as sponges, guides, scaffolds, and signal molecules to influence the oncogene or tumor suppressor expressions at transcriptional, post-transcriptional, and protein levels in crucial cellular processes. Currently, the dysregulated lncRNAs are reported to involve in the pathogenesis and progression of EC. Importantly, targeting EC-related lncRNAs through genome editing, RNA interference and molecule drugs may be one of the most potential therapeutic methods for the future EC treatment. In this review, we summarized the biological functions and molecular mechanisms of lncRNAs, including oncogenic lncRNAs and tumor suppressor lncRNAs in EC. In addition, we generalized the excellent potential lncRNA candidates for diagnosis, prognosis and therapy in EC. Finally, we discussed the current challenges and opportunities of lncRNAs for EC.

Long Non-Coding RNAs in the Cell Fate Determination of Neoplastic Thymic Epithelial Cells

Thymic Epithelial Tumors (TETs) arise from epithelial cells of the thymus and are very rare neoplasms comprising Thymoma, Thymic carcinoma, and Thymic Neuroendocrine tumors that still require in-depth molecular characterization. Long non-coding RNAs (lncRNAs) are emerging as relevant gene expression modulators involved in the deregulation of several networks in almost all types of human cancer, including TETs. LncRNAs act at different control levels in the regulation of gene expression, from transcription to translation, and modulate several pathways relevant to cell fate determination under normal and pathological conditions. The activity of lncRNAs is strongly dependent on their expression, localization, and post-transcriptional modifications. Starting from our recently published studies, this review focuses on the involvement of lncRNAs in the acquisition of malignant traits by neoplastic thymic epithelial cells, and describes the possible use of these molecules as targets for the design of novel therapeutic approaches specific for TET. Furthermore, the involvement of lncRNAs in myasthenia gravis (MG)-related thymoma, which is still under investigation, is discussed.

Long non-coding RNA NCK1-AS1 is overexpressed in esophageal squamous cell carcinoma and predicts survival

Long noncoding RNAs have shown pivotal regulatory roles in tumorigenesis and progression. NCK1-AS1 promotes cervical cancer, while its involvement in esophageal cancer is hardly known. This study enrolled 52 esophageal squamous cell carcinoma (ESCC) patients (30 males and 22 females) at the average age of 56.4 ± 6.6 years in the range from 46 to 70 years, explored the involvement of NCK1-AS1 in ESCC, and analyzed the possible interaction between NCK1-AS1 and TGF-β signaling. Changes in gene expression were analyzed using RT-qPCR and Western blot. Interactions between gene expressions were analyzed using ESCC cells with transient transfections. Cell invasion and migration were analyzed using Transwell assays. Our data showed that plasma NCK1-AS1 was overexpressed in ESCC patients and positively correlated with NCK1-AS1 expression in tumor tissues but not in non-tumor tissues. Moreover, high plasma NCK1-AS1 levels were accompanied with poor survival. TGF-β1 expression level was also increased in tumor tissues compared to the adjacent normal tissues and positively correlated with NCK1-AS1 in tumor tissues. TGF-β1 overexpression in ESCC cells did not affect NCK1-AS1 expression, while NCK1-AS1 overexpression in ESCC cells upregulated TGF-β1. Moreover, TGF-β1 and NCK1-AS1 overexpression increased ESCC cell migration and invasion, while TGF-β inhibitor reduced the effects of NCK1-AS1 overexpression. Overall, NCK1-AS1 may promote ESCC by upregulating TGF-β1.

A Pleiotropic Role of Long Non-Coding RNAs in the Modulation of Wnt/β-Catenin and PI3K/Akt/mTOR Signaling Pathways in Esophageal Squamous Cell Carcinoma: Implication in Chemotherapeutic Drug Response

Despite the availability of modern techniques for the treatment of esophageal squamous cell carcinoma (ESCC), tumor recurrence and metastasis are significant challenges in clinical management. Thus, ESCC possesses a poor prognosis and low five-year overall survival rate. Notably, the origin and recurrence of the cancer phenotype are under the control of complex cancer-related signaling pathways. In this review, we provide comprehensive knowledge about long non-coding RNAs (lncRNAs) related to Wnt/β-catenin and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway in ESCC and its implications in hindering the efficacy of chemotherapeutic drugs. We observed that a pool of lncRNAs, such as HERES, TUG1, and UCA1, associated with ESCC, directly or indirectly targets various molecules of the Wnt/β-catenin pathway and facilitates the manifestation of multiple cancer phenotypes, including proliferation, metastasis, relapse, and resistance to anticancer treatment. Additionally, several lncRNAs, such as HCP5 and PTCSC1, modulate PI3K/Akt/mTOR pathways during the ESCC pathogenesis. Furthermore, a few lncRNAs, such as AFAP1-AS1 and LINC01014, block the efficiency of chemotherapeutic drugs, including cisplatin, 5-fluorouracil, paclitaxel, and gefitinib, used for ESCC treatment. Therefore, this review may help in designing a better therapeutic strategy for ESCC patients.

Long Non-Coding RNA in Esophageal Cancer: A Review of Research Progress

In recent years, there has been significant progress in the diagnosis and treatment of esophageal cancer. However, owing to the lack of early diagnosis strategies and treatment targets, the prognosis of patients with esophageal cancer remains unsatisfactory. There is an urgent need to identify novel biomarkers and treatment targets for esophageal cancer. With the development of genomics, long-chain non-coding RNAs (LncRNAs), which were once considered transcriptional “noise,” are being identified and characterized rapidly in large numbers. Recent research shows that LncRNAs are closely related to a series of steps in tumor development and play an important regulatory role in DNA replication, transcription, and post-transcriptional regulation. The abnormal expression of LncRNAs leads to tumor cell proliferation, migration, invasion, and treatment resistance. This review focuses on the latest progress in research on the abnormal expression and functional mechanisms of LncRNAs in esophageal cancer. Further, it discusses the potential applications of these findings towards achieving an early diagnosis, improving treatment efficacy, and evaluating the prognosis of esophageal cancer.

LncRNA SNHG15: A potential therapeutic target in the treatment of colorectal cancer

The global burden of colorectal cancer (CRC) is increasing annually. CRC could develop from genetic and phenotypic factors involving changes in gene expression. Incredibly, the human genome transcribes into non-coding RNAs, among which long non-coding RNAs (lncRNAs) signify the most crucial part of the transcriptome in multicellular organisms. lncRNAs affect gene expression at multiple levels, from transcription to protein localization and stability. Recent studies have implicated lncRNA small nucleolar RNA host gene 15 (SNHG15) in cancers occurrence and progression. Previously, an indication suggests SNHG15 overexpression triggers proliferation, metastasis, and impedes apoptosis in CRC. Further, through its activity of binding micro-RNAs, lncRNA SNHG15 modulates genes associated with CRC progression and promotes CRC resistance to chemotherapeutic drugs. Here we reviewed recent findings on the various mechanisms and roles of lncRNA SNHG15 implicated in CRC tumorigenesis. We further highlight how SNHG15 plays a vital role in regulating critical pathways linked to the development and progression of CRC. Finally, we highlight how SNHG15 can be modulated for CRC treatments and the various therapeutic strategies to be implored when targeting SNHG15 in the context of CRC treatments. Findings from these studies present SNHG15 as a potential therapeutic target for preventing and treating CRC.

The various regulatory functions of long noncoding RNAs in apoptosis, cell cycle, and cellular senescence

Long noncoding RNAs (lncRNAs) are a group of noncoding cellular RNAs involved in significant biological phenomena such as differentiation, cell development, genomic imprinting, adjusting the enzymatic activity, regulating chromosome conformation, apoptosis, cell cycle, and cellular senescence. The misregulation of lncRNAs interrupting normal biological processes has been implicated in tumor formation and metastasis, resulting in cancer. Apoptosis and cell cycle, two main biological phenomena, are highly conserved and intimately coupled mechanisms. Hence, some cell cycle regulators can influence both programmed cell death and cell division. Apoptosis eliminates defective and unwanted cells, and the cell cycle enables cells to replicate themselves. The improper regulation of apoptosis and cell cycle contributes to numerous disorders such as neurodegenerative and autoimmune diseases, viral infection, anemia, and mainly cancer. Cellular senescence is a tumor-suppressing response initiated by environmental and internal stress factors. This phenomenon has recently attained more attention due to its therapeutic implications in the field of senotherapy. In this review, the regulatory roles of lncRNAs on apoptosis, cell cycle, and senescence will be discussed. First, the role of lncRNAs in mitochondrial dynamics and apoptosis is addressed. Next, the interaction between lncRNAs and caspases, pro/antiapoptotic proteins, and also EGFR/PI3K/PTEN/AKT/mTORC1 signaling pathway will be investigated. Furthermore, the effect of lncRNAs in the cell cycle is surveyed through interaction with cyclins, cdks, p21, and wnt/β-catenin/c-myc pathway. Finally, the function of essential lncRNAs in cellular senescence is mentioned.

LncRNA TUSC8 suppresses the proliferation and migration of esophageal cancer cells by downregulation of VEGFA

Objective: This study aims to determine the expression pattern of long non-coding RNA (lncRNA) TUSC8 in esophageal cancer tissues and cell lines, to investigate its effects on esophageal cancer cell proliferation and migration, and to explore the mechanism of TUSC8-mediated esophageal cancer suppression via VEGFA downregulation.

Patients and Methods: TUSC8 levels in esophageal cancer tissues and cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The influence of TUSC8 on clinical features in esophageal cancer patients was analyzed. After intervening TUSC8 expression in esophageal cancer cells, the proliferative and migratory abilities were examined in OE19 and TE-1 cells through a series of function experiments. The interaction between TUSC8 and VEGFA was assessed by the bioinformatics prediction and dual-luciferase reporter assay. Finally, the co-regulation of TUSC8 and VEGFA on esophageal cancer cell functions was evaluated.

Results: TUSC8 was downregulated in esophageal cancer tissues compared with normal ones. Identically, decreased TUSC8 expression was detected in esophageal cancer cell lines compared with control cells. Low TUSC8 expression predicted poor prognosis in patients with esophageal cancer. Knockdown of TUSC8 promoted the proliferative and migratory abilities in OE19 cells, whereas overexpression of TUSC8 resulted in opposite results in TE-1 cells. VEGFA was confirmed to be a target gene of TUSC8. Overexpression of VEGFA could reverse the regulatory effects of TUSC8 on esophageal cancer cell proliferation and migration.

Conclusions: LncRNA TUSC8 is downregulated in esophageal cancer tissues and cell lines. TUSC8 inhibits the proliferative and migratory abilities in esophageal cancer cells in vitro by negatively regulating VEGFA.

An Integrated Transcriptomics and Proteomics Analysis Implicates lncRNA MALAT1 in the Regulation of Lipid Metabolism

Long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is upregulated in various cancers, and its overexpression is associated with tumor growth and metastasis. MALAT1 has been recognized as a key player in the regulation of RNA splicing and transcription; however, the landscape of gene expression regulated by MALAT1 remains unclear. In this study, we employed an integrated transcriptomics and proteomics strategy to characterize the alterations in gene expression induced by MALAT1 knockdown in hepatocellular carcinoma (HCC) cells and identified 2662 differentially expressed transcripts and 1149 differentially expressed proteins. Interestingly, downregulation of MALAT1 reduced the abundances of multiple genes in the AMP-activated protein kinase (AMPK) signaling and biosynthesis of unsaturated fatty acids pathways. Further investigation showed that MALAT1 knockdown inhibited glucose uptake and lipogenesis by reducing the expression levels of these lipid metabolism related genes, which contributes to the oncogenic role of MALAT1 in tumor cell proliferation and invasion. This study uncovers the function of MALAT1 in the modulation of cancer lipid metabolism, reveals the underlying molecular mechanism, and further supports the potential therapeutic opportunities for targeting MALAT1 in HCC treatment.

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Multiomic analysis characterizes MALAT1-regulated gene expression in HCC cells.

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MALAT1 knockdown reduces the expression of genes involving in lipid metabolism.

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MALAT1 knockdown inhibits glucose uptake and lipogenesis.

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MALAT1 promotes HCC cell proliferation and migration through regulating lipid metabolism.

Integrative analysis of prognostic long non-coding RNAs with copy number variation in bladder cancer

Copy number variations (CNVs), which can affect the role of long non-coding RNAs (lncRNAs), are important genetic changes seen in some malignant tumors. We analyzed lncRNAs with CNV to explore the relationship between lncRNAs and prognosis in bladder cancer (BLCA). Messenger RNA (mRNA) expression levels, DNA methylation, and DNA copy number data of 408 BLCA patients were subjected to integrative bioinformatics analysis. Cluster analysis was performed to obtain different subtypes and differently expressed lncRNAs and coding genes. Weighted gene co-expression network analysis (WGCNA) was performed to identify the co-expression gene and lncRNA modules. CNV-associated lncRNA data and their influence on cancer prognosis were assessed with Kaplan-Meier survival curve. Multi-omics integration analysis revealed five prognostic lncRNAs with CNV, namely NR2F1-AS1, LINC01138, THUMPD3-AS1, LOC101928489,and TMEM147-AS1,and a risk-score signature related to overall survival in BLCA was identified. Moreover, validated results in another independent Gene Expression Omnibus (GEO) dataset, GSE31684, were consistent with these results. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that the mitogen-activated protein kinase (MAPK) signaling pathway, focal adhesion pathway, and Janus kinase-signal transducers and activators of transcription (JAK-STAT) signaling pathway were enriched in a high-risk score pattern, suggesting that imbalance in these pathways is closely related to tumor development. We revealed the prognosis-related lncRNAs by analyzing the expression profiles of lncRNAs and CNVs, which can be used as prognostic biomarkers for BLCA.

Effects of the lncRNA ENST00000623984 on colon cancer and the biological characteristics of colon cancer cells

The aim of this study was to explore the effects of the lncRNA ENST00000623984 on colorectal cancer. In this study, the expression levels of ENST000000623984 were first examined in tumor tissue and adjacent normal tissue from 40 patients with colorectal cancer and LoVo cells using quantitative real-time PCR. By siRNA transfection, ENST00000623984 expression was knocked down. Using flow cytometry, cell cycle progression and cell viability were examined in basal and knockdown LoVo cells. The CCK-8 assay was used to assess the cell proliferation rate, and the Transwell assay was used to determine the migration and invasion abilities. The ENST000000623984 expression level was increased in colorectal cancer. Knockdown of ENST000000623984 reduced cell viability, proliferation rate, cell migration and invasion. These results suggested that lncRNA ENST000000623984 may be involved in colorectal cancer development.

Treatment of Small Cell Lung Cancer with Lurbinectedin: A Review

BACKGROUND

Lurbinectedin was approved on June 15, 2020 by Food and Drug Administration with a brand name ZEPZELCA as the first systematic approved therapy for patients having Small Cell Lung Cancer (SCLC).

OBJECTIVES

In this review, an attempt is made to summarize different aspects of Lurbinectedin, including the pathophysiology, chemistry, chemical synthesis, mechanism of action, adverse reactions, including pharmacokinetics of lurbinectedin. Special attention is given to various reported clinical trials of lurbinectedin.

METHODS

A comprehensive literature search was conducted in the relevant databases like ScienceDirect, PubMed, ResearchGate and Google Scholar to identify studies. Further upon a thorough study of these reports, significant findings/data were collected and compiled under suitable headings. Important findings related to clinical trials have been tabulated.

CONCLUSION

Lurbinectedin is known to act by inhibiting the active transcription of encoding genes, thereby bringing about the suppression of tumour related macrophages with an impact on tumour atmosphere. Lurbinectedin has emerged as a potential drug candidate for the treatment of small cell lung cancer (SCLC).

Functional roles of lncRNAs in the pathogenesis and progression of cancer

Long noncoding RNAs (lncRNAs) act as regulators of gene expression and pivotal transcriptional regulators in cancer cells via diverse mechanisms. lncRNAs involves a variety of pathological and biological activities, such as apoptosis, cell proliferation, metastasis, and invasion. By using microarray and RNA sequencing, it was identified that dysregulation of lncRNAs affects the tumorigenesis process. Taken together, these lncRNAs are putative biomarker and therapeutic target in human malignancies. In this review, I discuss the latest finding regarding the dysregulation of some important lncRNAs and their diverse mechanisms of these lncRNAs in the pathogenesis and progression of certain cancers; also, I summarize the possible roles of lncRNAs in clinical application for diagnosis and prognosis of cancer.

Long Intergenic Non-Coding RNAs in HNSCC: From "Junk DNA" to Important Prognostic Factor

Head and neck squamous cell carcinoma is one of the most common and fatal cancers worldwide. Even a multimodal approach consisting of standard chemo- and radiotherapy along with surgical resection is only effective in approximately 50% of the cases. The rest of the patients develop a relapse of the disease and acquire resistance to treatment. Especially this group of individuals needs novel, personalized, targeted therapy. The first step to discovering such solutions is to investigate the tumor microenvironment, thus understanding the role and mechanism of the function of coding and non-coding sequences of the human genome. In recent years, RNA molecules gained great interest when the complex character of their impact on our biology allowed them to come out of the shadows of the "junk DNA" label. Furthermore, long non-coding RNAs (lncRNA), specifically the intergenic subgroup (lincRNA), are one of the most aberrantly expressed in several malignancies, which makes them particularly promising future diagnostic biomarkers and therapeutic targets. This review contains characteristics of known and validated lincRNAs in HNSCC, such as XIST, MALAT, HOTAIR, HOTTIP, lincRNA-p21, LINC02487, LINC02195, LINC00668, LINC00519, LINC00511, LINC00460, LINC00312, and LINC00052, with a description of their prognostic abilities. Even though much work remains to be done, lincRNAs are important factors in cancer biology that will become valuable biomarkers of tumor stage, outcome prognosis, and contribution to personalized medicine.

si-MALAT1 attenuates thymic cancer cell proliferation and promotes apoptosis via the miR-145-5p/HMGA2 pathway

Metastasis-associated-lung-adenocarcinoma-transcript-1 (MALAT1) is a long non-coding RNA that is considered a potential tumor marker. The present study aimed to investigate the effect and mechanism of MALAT1 on cell proliferation and apoptosis in thymic cancer cells. IU-TAB-1, A549, HCT-116 and 293T cells were screened by reverse transcription-quantitative PCR to assess high-mobility group AT-hook 2 (HMGA2) expression in various types of cancer cells and were transfected with small interfering (si)RNA targeting MALAT1 (si-MALAT1). Cell proliferation was evaluated by Cell Counting Kit-8 assay. Cell apoptosis and cell cycle were examined using flow cytometry. The protein expression of cyclin D1, cyclin E, Bax, Bcl-2 and HMGA2 was determined by western blot analysis, while the associations between MALAT1 and microRNA (miR)-145-5p and between HMGA2 and miR-145-5p were determined by luciferase reporter assay. Among the four cell lines evaluated, IU-TAB-1 showed the highest expression of MALAT1; thus, IU-TAB-1 cells were selected for subsequent experiments. Compared with the findings in the control group, si-MALAT1 significantly decreased the cell proliferation of IU-TAB-1 cells, whereas the apoptosis levels and number of cells in G₂ phase were increased. The protein expression levels of cyclin D1, cyclin E, Bcl-2 and HMGA2 were significantly decreased in the si-MALAT1 group compared with those in the control group, while Bax levels were significantly increased. After treatment with si-MALAT1 in combination with miR-145-5p mimics or inhibitors, cell proliferation and apoptosis were respectively enhanced and inhibited in IU-TAB-1 cells. miR-145-5p inhibited the luciferase activity of IU-TAB-1 cells transfected with the MALAT1 or HMGA2 3' untranslated region. In conclusion, si-MALAT1 significantly attenuated cell proliferation and apoptosis via the miR-145-5p/HMGA2 pathway in thymic cancer cells.

lncRNA Profiles Enable Prognosis Prediction and Subtyping for Esophageal Squamous Cell Carcinoma

Long non-coding RNAs (lncRNAs) have emerged as useful prognostic markers in many tumors. In this study, we investigated the potential application of lncRNA markers for the prognostic prediction of esophageal squamous cell carcinoma (ESCC). We identified ESCC-associated lncRNAs by comparing ESCC tissues with normal tissues. Subsequently, Kaplan–Meier (KM) method in combination with the univariate Cox proportional hazards regression (UniCox) method was used to screen prognostic lncRNAs. By combining the differential and prognostic lncRNAs, we developed a prognostic model using cox stepwise regression analysis. The obtained prognostic prediction model could effectively predict the 3- and 5-year prognosis and survival of ESCC patients by time-dependent receiver operating characteristic (ROC) curves (area under curve = 0.87 and 0.89, respectively). Besides, a lncRNA-based classification of ESCC was generated using k-mean clustering method and we obtained two clusters of ESCC patients with association with race and Barrett’s esophagus (BE) (both P < 0.001). Finally, we found that lncRNA AC007128.1 was upregulated in both ESCC cells and tissues and associated with poor prognosis of ESCC patients. Furthermore, AC007128.1 could promote epithelial-mesenchymal transition (EMT) of ESCC cells by increasing the activation of MAPK/ERK and MAPK/p38 signaling pathways. Collectively, our findings indicated the potentials of lncRNA markers in the prognosis, molecular subtyping, and EMT of ESCC.

Current Trends in Prevalence and Role of Long Noncoding RNA and Gene Fusion in Prostate Cancer: An Overview

Objectives The aim of this study is to analyze the current scenario in the diagnostic modalities for prostate cancer.

Materials and Methods We searched PubMed, Google Scholar, and ResearchGate for relevant data. Articles published in the last 10 years were taken into consideration. The role of long noncoding RNA and gene fusion products in the context of prostate cancer was reviewed, which included their roles in diagnosis, prognosis, and assessment of response to therapy.

Results Several long noncoding RNAs (lncRNA) have been isolated and have been shown to be useful in diagnosing and prognosticating prostate cancer. We have also looked into the role of TMPRSS2:ERG gene fusion in prostate carcinoma diagnosis. These molecular parameters have been looked into due to the fact that the current parameters in use such as prostate-specific antigen have several drawbacks that limit their potential.

Pathways and role of MALAT1 in esophageal and gastric cancer

Esophageal cancer (EC) and gastric cancer (GC) often have an unfavorable prognosis. Therefore, research is being conducted to identify the molecular mechanisms underlying the tumorigenesis and progression of GC and EC, and to indicate novel therapeutic targets and clinically applicable biomarkers. The dysregulations and roles of long non-coding RNAs (lncRNAs) have been widely reported, and current published literature has shown that lncRNAs play important regulatory roles in the carcinogenesis and progression of EC and GC. The lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been investigated in a number of studies with regard to its pathogenic pathways and association with the prognosis of gastric and esophageal malignancies. As literature on the topic of MALAT1 in EC and GC continues to emerge, the present review aims to summarize all current knowledge on the association between MALAT1 expression and esophagogastric malignancies and to describe the pathogenic pathways and possible prognostic role of MALAT1 in esophagogastric cancer. As research studies on MALAT1 pathways in esophagogastric malignancies are ongoing, new possibilities for the diagnosis, prognosis and therapy of GC and EC are likely to be identified.

Long non‑coding RNA LINC00491 promotes proliferation and inhibits apoptosis in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor in the human digestive system, which affects the physical and mental health of the patient. Long non‑coding (lnc)RNAs have been revealed to play an important role in human malignant tumors. Moreover, long intergenic non‑protein coding RNA 491 (LINC00491) is a newly discovered lncRNA that can affect the prognosis of cancer. The present study aimed to explore the expression of LINC00491 in ESCC tissues and cells. The reverse transcription‑quantitative PCR results suggested that LINC00491 was upregulated in ESCC tissues and cells. LINC00491 expression in esophageal squamous cell carcinoma cells were knocked down. Cell Counting Kit‑8, wound healing, Transwell and apoptosis assays were performed to detect the effects of LINC00491 knockdown on cell biological behavior. The results showed that lower expression of LINC00491 resulted in decreased cell proliferation and migration and increased the apoptosis rate. Therefore, the present results indicated that lncRNA LINC00491 promoted the biological processes of ESCC, and thus LINC00491 may be a potential therapeutic target for ESCC.

LncRNA MTX2-6 Suppresses Cell Proliferation by Acting as ceRNA of miR-574-5p to Accumulate SMAD4 in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) has been one of the key causes of cancer deaths worldwide. It has been found that long non-coding RNA (lncRNA) is related to the generation and progression of various cancers (including ESCC). However, there are still many lncRNAs related to ESCC whose functions and molecular mechanisms have not been clearly elucidated. In this study, we first reported that lncRNA MTX2-6 was significantly downregulated in ESCC tissues and cell lines. The decreased expression of MTX2-6 is closely related to larger tumor and worse prognosis of ESCC patients. Through a series of functional experiments, we detected that overexpressed MTX2-6 inhibited cell proliferation and promoted cell apoptosis of ESCC in vitro and in vivo. Further studies showed that MTX2-6 exerts as a competing endogenous RNA (ceRNA) by binding miR-574-5p and elevates the expression of SMAD4 in ESCC. In summary, our results clarify the tumor suppressor roles of MTX2-6/miR-574-5p/SMAD4 axis in the progression of ESCC and provide emerging therapeutic targets for ESCC patients.

Involvement of long non-coding RNAs in the progression of esophageal cancer

Esophageal cancer (EC) is one of the most common malignant tumors of the digestive system with high incidence and mortality rate worldwide. Therefore, exploring the pathogenesis of EC and searching for new targeted therapies are the current research hotspot for EC treatment. Long non‐coding RNAs (lncRNAs) are endogenous RNAs with more than 200 nucleotides, but without protein‐coding function. In recent years, lncRNAs have gradually become the focuses in the field of non‐coding RNA. Some lncRNAs have been proved to be closely related to the pathogenesis of EC. Many lncRNAs are abnormally expressed in EC and participate in many biological processes including cell proliferation, apoptosis, and metastasis by inhibiting or promoting target gene expression. LncRNAs can also regulate the progression of EC through epithelial‐mesenchymal transformation (EMT), which is closely related to the occurrence, development, and prognosis of EC. In this article, we review and discuss the involvement of lncRNAs in the progression of EC.

The role of long noncoding RNAs in regulating invasion and metastasis of malignant tumors

Long noncoding RNAs (lncRNAs) are a group of non-protein-coding transcripts exceeding 200 nucleotides in length, which are emerging as key players in various fundamental biological processes. Furthermore, it is increasingly recognized that mutation and dysregulation of lncRNAs contribute importantly to a variety of human diseases, particularly human cancers. Previous studies have revealed that altered lncRNAs have a close association with tumorigenesis, metastasis, prognosis and diagnosis of cancers. The present review aims to exhibit a brief overview of the associated reports of lncRNAs in cancers, including colorectal cancer, gastric cancer, lung adenocarcinoma, nasopharyngeal carcinoma, cervical cancer and esophageal cancer. Altogether, we argue that lncRNAs have potential as new biomarkers in cancer prognosis and diagnosis, and as promising therapeutic targets for the prevention and treatment of human cancers.

TRA2A Binds With LncRNA MALAT1 To Promote Esophageal Cancer Progression By Regulating EZH2/β-catenin Pathway

The RNA binding protein TRA2A, a member of the transformer 2 homolog family, plays a crucial role in the alternative splicing of pre-mRNA. However, it remains unclear whether TRA2A is involved in non-coding RNA regulation and, if so, what are the functional consequences. By analyzing expression profiling data, we found that TRA2A is highly expressed in esophageal cancer and is associated with disease-free survival and overall survival time. Subsequent gain- and loss-of-function studies demonstrated that TRA2A promotes proliferation and migration of esophageal squamous cell carcinoma and adenocarcinoma cells. RNA immunoprecipitation and RNA pull-down assay indicated that TRA2A can directly bind specific sites on MALAT1 in cells. In addition, ectopic expression or depletion of TRA2A leads to MALAT expression changes accordingly, thus modulates EZH2/β-catenin pathway. Together, these findings elucidated that TRA2A triggers carcinogenesis via MALAT1 mediated EZH2/β-catenin axis in esophageal cancer cells.

Multifaceted Roles of Long Non-coding RNAs in Head and Neck Cancer

The majority of RNA transcripts are non-coding RNA (ncRNA) transcripts with lengths exceeding 200 nucleotides that are not translated into protein. Unlike microRNAs (miRNAs), long ncRNAs (lncRNAs) are not confined to a single mechanism of action but have a large and diverse role in biological processes as they can function as transcription regulators, decoys, scaffolds, and enhancer RNAs. Currently, many lncRNA molecules are under investigation for their role in tumorigenesis, metastasis, and prognosis in different types of cancer. This review not only summarizes the characteristics and functions of lncRNAs but also discusses the therapeutic implications and applications of lncRNAs with roles associated with head and neck cancer. Our aim is to pinpoint the potential way to perturb specific lncRNAs for future therapeutic use.

Aberrantly upregulated FAM83H-AS1 facilitates malignant progression of esophageal squamous cell carcinoma

The biological roles of the newly identified long non-coding RNA family with sequence similarity 83 member H antisense 1 (FAM83H-AS1) in esophageal squamous cell carcinoma (ESCC) have remained largely elusive. In the present study, it was determined that, in comparison with paired para-tumorous tissues or normal esophageal epithelial cells, FAM83H-AS1 expression in cancer tissues and cell lines was markedly upregulated. Furthermore, FAM83H-AS1 expression was significantly elevated in patients with ESCC and lymph node metastasis or a late TNM stage, while no association with any other clinicopathological characteristics was detected. Furthermore, the overall and disease-free survival, as assessed by the Kaplan-Meier method, were significantly shortened in patients with high FAM83H-AS1 expression. A functional study then uncovered that knockdown of FAM83H-AS1 significantly suppressed the proliferation and migration of ESCC cells. The present results suggested that FAM83H-AS1 may facilitate the malignant progression of ESCC and may be utilized as a prognostic predictor and possibly a novel therapeutic target in ESCC that warrants further exploration.

Association of long noncoding RNA MALAT1 polymorphisms with gastric cancer risk in Korean individuals

Background

Metastasis‐associated lung adenocarcinoma transcript 1 (MALAT1) drives tumorigenesis of various human cancers. However, the association between MALAT1 variants and gastric cancer (GC) risk is unknown. We performed a case‐control study to evaluate the possible association between rs619586 and rs3200401 SNPs in MALAT and GC risk.

Methods

Samples from 458 patients with GC and 381 controls were genotyped using the TaqMan genotyping assay.

Results

In stratified analyses, we observed that rs3200401 CT in the codominant model and CT+TT in the dominant model were associated with increased GC risk in male patients (CT: odds ratio [OR] = 1.81, 95% confidence interval [CI] = 1.09–3.01, p = 0.022; CT+TT: OR = 1.74, 95% CI = 1.07–2.83, p = 0.026), and the differentiated (CT: OR =1.79, 95% CI = 1.18–2.73, p = 0.007; CT+TT: OR = 1.76, 95% CI = 1.17–2.64, p = 0.007), and intestinal (CT: OR = 1.67, 95% CI = 1.11–2.49, p = 0.013; CT+TT: OR = 1.68, 95% CI = 1.14–2.47, p = 0.009) GC subgroups.

Conclusion

MALAT1 rs3200401 increases GC susceptibility and might affect GC development. Further studies are needed to validate our results in large populations and different ethnic groups.