Identification of the lncRNA, AK156230, as a novel regulator of cellular senescence in mouse embryonic fibroblasts

Orchestrating Cellular Balance: ncRNAs and RNA Interactions at the Dominant of Autophagy Regulation in Cancer

Autophagy, a complex and highly regulated cellular process, is critical for the maintenance of cellular homeostasis by lysosomal degradation of cellular debris, intracellular pathogens, and dysfunctional organelles. It has become an interesting and attractive topic in cancer because of its dual role as a tumor suppressor and cell survival mechanism. As a highly conserved pathway, autophagy is strictly regulated by diverse non-coding RNAs (ncRNAs), ranging from short and flexible miRNAs to lncRNAs and even circRNAs, which largely contribute to autophagy regulatory networks via complex RNA interactions. The potential roles of RNA interactions during autophagy, especially in cancer procession and further anticancer treatment, will aid our understanding of related RNAs in autophagy in tumorigenesis and cancer treatment. Herein, we mainly summarized autophagy-related mRNAs and ncRNAs, also providing RNA-RNA interactions and their potential roles in cancer prognosis, which may deepen our understanding of the relationships between various RNAs during autophagy and provide new insights into autophagy-related therapeutic strategies in personalized medicine.

The role of ncRNA in the co-regulation of autophagy and exosome pathways during cancer progression

Since its discovery a few decades ago, autophagy has been recognized as a crucial signaling pathway, linked to the recycling of cellular components in nutrient stress. Autophagy is a two-way sword, playing a dual role in tumorigenesis. In this catabolic process, dysfunctional organelles, biomolecules, and misfolded proteins are sequestered in the autophagosome and sent to the lysosome for degradation. Alongside, there are cellular messengers called exosomes, which are released from cells and are known to communicate and regulate metabolism in recipient cells. Multivesicular bodies (MVB) act as the intricate link between autophagy and exosome pathways. The continuous crosstalk between the two pathways is coordinated and regulated by multiple players among which ncRNA is the emerging candidates. The exosomes carry varied cargo of which non-coding RNA exerts an immediate regulatory effect on recipient cells. ncRNA is known to exhibit dual behavior in both promoting and inhibiting tumor growth. There is increasing evidence for the involvement of ncRNAs' in the regulation of different hallmarks of cancer. Different ncRNAs are involved in the co-regulation of autophagy and exosome pathways and therefore represent a superior therapeutic approach to target cancer chemoresistance. Here, we will discuss the ncRNA involved in regulating autophagy, and exosomes pathways and its relevance in cancer therapeutics.

Lnc-ing epigenetic mechanisms with autophagy and cancer drug resistance

Long noncoding RNAs (lncRNAs) comprise a diverse class of RNA molecules that regulate various physiological processes and have been reported to be involved in several human pathologies ranging from neurodegenerative disease to cancer. Therapeutic resistance is a major hurdle for cancer treatment. Over the past decade, several studies has emerged on the role of lncRNAs in cancer drug resistance and many trials have been conducted employing them. LncRNAs also regulate different cell death pathways thereby maintaining a fine balance of cell survival and death. Autophagy is a complex cell-killing mechanism that has both cytoprotective and cytotoxic roles. Similarly, autophagy can lead to the induction of both chemosensitization and chemoresistance in cancer cells upon therapeutic intervention. Recently the role of lncRNAs in the regulation of autophagy has also surfaced. Thus, lncRNAs can be used in cancer therapeutics to alleviate the challenges of chemoresistance by targeting the autophagosomal axis. In this chapter, we discuss about the role of lncRNAs in autophagy-mediated cancer drug resistance and its implication in targeted cancer therapy.

nc886, a Non-Coding RNA, Is a New Biomarker and Epigenetic Mediator of Cellular Senescence in Fibroblasts

Functional studies of organisms and human models have revealed that epigenetic changes can significantly impact the process of aging. Non-coding RNA (ncRNA), one of epigenetic regulators, plays an important role in modifying the expression of mRNAs and their proteins. It can mediate the phenotype of cells. It has been reported that nc886 (=vtRNA2-1 or pre-miR-886), a long ncRNA, can suppress tumor formation and photo-damages of keratinocytes caused by UVB. The aim of this study was to determine the role of nc886 in replicative senescence of fibroblasts and determine whether substances capable of controlling nc886 expression could regulate cellular senescence. In replicative senescence fibroblasts, nc886 expression was decreased while methylated nc886 was increased. There were changes of senescence biomarkers including SA-β-gal activity and expression of p16INK4A and p21Waf1/Cip1 in senescent cells. These findings indicate that the decrease of nc886 associated with aging is related to cellular senescence of fibroblasts and that increasing nc886 expression has potential to suppress cellular senescence. AbsoluTea Concentrate 2.0 (ATC) increased nc886 expression and ameliorated cellular senescence of fibroblasts by inhibiting age-related biomarkers. These results indicate that nc886 has potential as a new target for anti-aging and that ATC can be a potent epigenetic anti-aging ingredient.

Interleukin-27 promotes autophagy in human serum-induced primary macrophages via an mTOR- and LC3-independent pathway

Interleukin-27 (IL-27) is a cytokine that suppresses human immunodeficiency virus (HIV)-1 infection in macrophages and is considered as an immunotherapeutic reagent for infectious diseases. It is reported that IL-27 suppresses autophagy in Mycobacterium tuberculosis-infected macrophages; however, a role for IL-27 on autophagy induction has been less studied. In this study, we investigated the impact of IL-27 in both autophagy induction and HIV-1 infection in macrophages. Primary human monocytes were differentiated into macrophages using human AB serum (huAB) alone, macrophage-colony stimulating factor (M-CSF) alone, or a combination of IL-27 with huAB or M-CSF. Electron microscopy and immunofluorescence staining demonstrated that a 20-fold increase in autophagosome formation was only detected in IL-27 + huAB-induced macrophages. Western blot analysis indicated that the autophagosome induction was not linked to either dephosphorylation of the mammalian target of rapamycin (mTOR) or lipidation of microtubule-associated protein 1A/1B-light chain 3 (LC3), an autophagosomal marker, implying that IL-27 can induce autophagy through a novel non-canonical pathway. Here we show for the first time that IL-27 induces autophagy during monocyte-to-macrophage differentiation in a subtype-dependent manner.

The role of epigenetics and non-coding RNAs in autophagy: A new perspective for thorough understanding

Autophagy is a major self-degradative intracellular process required for the maintenance of homeostasis and promotion of survival in response to starvation. It plays critical roles in a large variety of physiological and pathological processes. On the other hand, aberrant regulation of autophagy can lead to various cancers and neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Crohn's disease. Emerging evidence strongly supports that epigenetic signatures, related non-coding RNA profiles, and their cross-talking are significantly associated with the control of autophagic responses. Therefore, it may be helpful and promising to manage autophagic processes by finding valuable markers and therapeutic approaches. Although there is a great deal of information on the components of autophagy in the cytoplasm, the molecular basis of the epigenetic regulation of autophagy has not been completely elucidated. In this review, we highlight recent research on epigenetic changes through the expression of autophagy-related genes (ATGs), which regulate autophagy, DNA methylation, histone modifications as well as non-coding RNAs, including long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and their relationship with human diseases, that play key roles in causing autophagy-related diseases.

LncRNAs as Regulators of Autophagy and Drug Resistance in Colorectal Cancer

Colorectal cancer (CRC) is a common malignancy with 1. 8 million cases in 2018. Autophagy helps to maintain an adequate cancer microenvironment in order to provide nutritional supplement under adverse conditions such as starvation and hypoxia. Additionally, most of the cases of CRC are unresponsive to chemotherapy, representing a significant challenge for cancer therapy. Recently, autophagy induced by therapy has been shown as a unique mechanism of resistance to anticancer drugs. In this regard, long non-coding RNAs (lncRNAs) analysis are important for cancer detection, progression, diagnosis, therapy response, and prognostic values. With increasing development of quantitative detection techniques, lncRNAs derived from patients' non-invasive samples (i.e., blood, stools, and urine) has become into a novel approach in precision oncology. Tumorspecific GAS5, HOTAIR, H19, and MALAT are novels CRC related lncRNAs detected in patients. Nonetheless, the effect and mechanism of lncRNAs in cancer autophagy and chemoresistance have not been extensively characterized. Chemoresistance and autophagy are relevant for cancer treatment and lncRNAs play a pivotal role in resistance acquisition for several drugs. LncRNAs such as HAGLROS, KCNQ1OT1, and H19 are examples of lncRNAs related to chemoresistance leaded by autophagy. Finally, clinical implications of lncRNAs in CRC are relevant, since they have been associated with tumor differentiation, tumor size, histological grade, histological types, Dukes staging, degree of differentiation, lymph node metastasis, distant metastasis, recurrent free survival, and overall survival (OS).

LncRNAs Regulatory Networks in Cellular Senescence

Long noncoding RNAs (lncRNAs) are a class of transcripts longer than 200 nucleotides with no open reading frame. They play a key role in the regulation of cellular processes such as genome integrity, chromatin organization, gene expression, translation regulation, and signal transduction. Recent studies indicated that lncRNAs are not only dysregulated in different types of diseases but also function as direct effectors or mediators for many pathological symptoms. This review focuses on the current findings of the lncRNAs and their dysregulated signaling pathways in senescence. Different functional mechanisms of lncRNAs and their downstream signaling pathways are integrated to provide a bird’s-eye view of lncRNA networks in senescence. This review not only highlights the role of lncRNAs in cell fate decision but also discusses how several feedback loops are interconnected to execute persistent senescence response. Finally, the significance of lncRNAs in senescence-associated diseases and their therapeutic and diagnostic potentials are highlighted.

Long non-coding RNAs involved in autophagy regulation

Autophagy degrades non-functioning or damaged proteins and organelles to maintain cellular homeostasis in a physiological or pathological context. Autophagy can be protective or detrimental, depending on its activation status and other conditions. Therefore, autophagy has a crucial role in a myriad of pathophysiological processes. From the perspective of autophagy-related (ATG) genes, the molecular dissection of autophagy process and the regulation of its level have been largely unraveled. However, the discovery of long non-coding RNAs (lncRNAs) provides a new paradigm of gene regulation in almost all important biological processes, including autophagy. In this review, we highlight recent advances in autophagy-associated lncRNAs and their specific autophagic targets, as well as their relevance to human diseases such as cancer, cardiovascular disease, diabetes and cerebral ischemic stroke.

Molecular and phenotypic biomarkers of aging

Individuals of the same age may not age at the same rate. Quantitative biomarkers of aging are valuable tools to measure physiological age, assess the extent of ‘healthy aging’, and potentially predict health span and life span for an individual. Given the complex nature of the aging process, the biomarkers of aging are multilayered and multifaceted. Here, we review the phenotypic and molecular biomarkers of aging. Identifying and using biomarkers of aging to improve human health, prevent age-associated diseases, and extend healthy life span are now facilitated by the fast-growing capacity of multilevel cross-sectional and longitudinal data acquisition, storage, and analysis, particularly for data related to general human populations. Combined with artificial intelligence and machine learning techniques, reliable panels of biomarkers of aging will have tremendous potential to improve human health in aging societies.

The emergence of noncoding RNAs as Heracles in autophagy

Macroautophagy/autophagy is a catabolic process that is widely found in nature. Over the past few decades, mounting evidence has indicated that noncoding RNAs, ranging from small noncoding RNAs to long noncoding RNAs (lncRNAs) and even circular RNAs (circRNAs), mediate the transcriptional and post-transcriptional regulation of autophagy-related genes by participating in autophagy regulatory networks. The differential expression of noncoding RNAs affects autophagy levels at different physiological and pathological stages, including embryonic proliferation and differentiation, cellular senescence, and even diseases such as cancer. We summarize the current knowledge regarding noncoding RNA dysregulation in autophagy and investigate the molecular regulatory mechanisms underlying noncoding RNA involvement in autophagy regulatory networks. Then, we integrate public resources to predict autophagy-related noncoding RNAs across species and discuss strategies for and the challenges of identifying autophagy-related noncoding RNAs. This article will deepen our understanding of the relationship between noncoding RNAs and autophagy, and provide new insights to specifically target noncoding RNAs in autophagy-associated therapeutic strategies.