The multiple molecular dimensions of long noncoding RNAs that regulate gene expression and tumorigenesis

Crosstalk between m6A modification and non-coding RNAs in HCC

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide, with high morbidity and occurrence. Although various therapeutic approaches have been rapidly developed in recent years, the underlying molecular mechanisms in the pathogenesis of HCC remain enigmatic. The N6-methyladenosine (m6A) RNA modification is believed to regulate RNA metabolism and further gene expression. This process is intricately regulated by multiple regulators, such as methylases and demethylases. Non-coding RNAs (ncRNAs) are involved in the regulation of the epigenetic modification, mRNA transcription and other biological processes, exhibiting crucial roles in tumor occurrence and development. The m6A-ncRNA interaction has been implicated in the malignant phenotypes of HCC and plays an important role in drug resistance. This review summarizes the effect of m6A-ncRNA crosstalk on HCC progression and their clinical implications as prognostic markers and therapeutic targets in this disease.

Imprinted Long Non-Coding RNAs in Mammalian Development and Disease

Imprinted genes play diverse roles in mammalian development, homeostasis, and disease. Most imprinted chromosomal domains express one or more long non-coding RNAs (lncRNAs). Several of these lncRNAs are strictly nuclear and their mono-allelic expression controls in cis the expression of protein-coding genes, often developmentally regulated. Some imprinted lncRNAs act in trans as well, controlling target gene expression elsewhere in the genome. The regulation of imprinted gene expression-including that of imprinted lncRNAs-is susceptible to stochastic and environmentally triggered epigenetic changes in the early embryo. These aberrant changes persist during subsequent development and have long-term phenotypic consequences. This review focuses on the expression and the cis- and trans-regulatory roles of imprinted lncRNAs and describes human disease syndromes associated with their perturbed expression.

Exosomal LncRNAs in Gastrointestinal Cancer: Biological Functions and Emerging Clinical Applications

Due to the lack of specific and effective biomarkers and therapeutic targets, the early diagnosis and treatment of gastrointestinal cancer remain unsatisfactory. As a type of nanosized vesicles derived from living cells, exosomes mediate cell-to-cell communication by transporting bioactive molecules, thus participating in the regulation of many pathophysiological processes. Recent evidence has revealed that several long non-coding RNAs (lncRNAs) are enriched in exosomes. Exosomes-mediated lncRNAs delivery is critically involved in various aspects of gastrointestinal cancer progression, such as tumor proliferation, metastasis, angiogenesis, stemness, immune microenvironment, and drug resistance. Exosomal lncRNAs represent promising candidates to act as the diagnosis biomarkers and anti-tumor targets. This review introduces the major characteristics of exosomes and lncRNAs and describes the biological functions of exosomal lncRNAs in gastrointestinal cancer development. The preclinical studies on using exosomal lncRNAs to monitor and treat gastrointestinal cancer are also discussed, and the opportunities and challenges for translating them into clinical practice are evaluated.

Innate Immunity in Cardiovascular Diseases-Identification of Novel Molecular Players and Targets

During the past few years, unexpected developments have driven studies in the field of clinical immunology. One driver of immense impact was the outbreak of a pandemic caused by the novel virus SARS-CoV-2. Excellent recent reviews address diverse aspects of immunological re-search into cardiovascular diseases. Here, we specifically focus on selected studies taking advantage of advanced state-of-the-art molecular genetic methods ranging from genome-wide epi/transcriptome mapping and variant scanning to optogenetics and chemogenetics. First, we discuss the emerging clinical relevance of advanced diagnostics for cardiovascular diseases, including those associated with COVID-19-with a focus on the role of inflammation in cardiomyopathies and arrhythmias. Second, we consider newly identified immunological interactions at organ and system levels which affect cardiovascular pathogenesis. Thus, studies into immune influences arising from the intestinal system are moving towards therapeutic exploitation. Further, powerful new research tools have enabled novel insight into brain-immune system interactions at unprecedented resolution. This latter line of investigation emphasizes the strength of influence of emotional stress-acting through defined brain regions-upon viral and cardiovascular disorders. Several challenges need to be overcome before the full impact of these far-reaching new findings will hit the clinical arena.

A novel classification of HCC basing on fatty-acid-associated lncRNA

Aberrant long noncoding RNA (lncRNA) expression and fatty acid signaling dysfunction both contribute to hepatocellular carcinoma (HCC) occurrence and development. However, the relationship and interaction mechanism between lncRNAs and fatty acid signaling in HCC remain unclear. Data regarding RNA expression and clinical outcomes for patients with HCC were obtained from The Cancer Genome Atlas (TCGA), HCCDB, and the Gene Expression Omnibus (GEO) databases. Hallmark pathways were identified using the single-sample gene set enrichment analysis (ssGSEA) method. ConsensusClusterPlus was used to establish a consistency matrix for classifying samples into three subtypes. A risk signature was established, and predictive values for key lncRNAs related to prognosis were evaluated using Kaplan-Meier analysis and receiver operating characteristic curves. The ESTIMATE algorithm, MCP-Counter, and ssGSEA were used to evaluate the characteristics of the tumor immune microenvironment. The CTRP2.0 and PRISM were used to analyze drug sensitivity in HCC subtypes. We discovered seven fatty-acid-associated lncRNAs with predictive prognostic capabilities, including TRAF3IP2-AS1, SNHG10, AL157392.2, LINC02641, AL357079.1, AC046134.2, and A1BG-AS. Three subtypes were obtained, which presented with differences in prognosis, clinical information, mutation features, pathway traits, immune characteristics, and drug sensitivity. The seven key lncRNAs identified in this study might serve as promising biomarkers for predicting prognosis in patients with HCC, and the three HCC subtypes classified according to lncRNA expression profiles could improve HCC classification.