Long noncoding RNA ADIRF antisense RNA 1 upregulates insulin receptor substrate 1 to decrease the aggressiveness of osteosarcoma by sponging microRNA-761

Osteosarcoma in a ceRNET perspective

Osteosarcoma (OS) is the most prevalent and fatal type of bone tumor. It is characterized by great heterogeneity of genomic aberrations, mutated genes, and cell types contribution, making therapy and patients management particularly challenging. A unifying picture of molecular mechanisms underlying the disease could help to transform those challenges into opportunities.This review deeply explores the occurrence in OS of large-scale RNA regulatory networks, denominated "competing endogenous RNA network" (ceRNET), wherein different RNA biotypes, such as long non-coding RNAs, circular RNAs and mRNAs can functionally interact each other by competitively binding to shared microRNAs. Here, we discuss how the unbalancing of any network component can derail the entire circuit, driving OS onset and progression by impacting on cell proliferation, migration, invasion, tumor growth and metastasis, and even chemotherapeutic resistance, as distilled from many studies. Intriguingly, the aberrant expression of the networks components in OS cells can be triggered also by the surroundings, through cytokines and vesicles, with their bioactive cargo of proteins and non-coding RNAs, highlighting the relevance of tumor microenvironment. A comprehensive picture of RNA regulatory networks underlying OS could pave the way for the development of innovative RNA-targeted and RNA-based therapies and new diagnostic tools, also in the perspective of precision oncology.

Elevated Norepinephrine Stimulates Adipocyte Hyperplasia in Ovine Fetuses With Placental Insufficiency and IUGR

Prevailing hypoxemia and hypoglycemia in near-term fetuses with placental insufficiency-induced intrauterine growth restriction (IUGR) chronically increases norepinephrine concentrations, which lower adrenergic sensitivity and lipid mobilization postnatally, indicating a predisposition for adiposity. To determine adrenergic-induced responses, we examined the perirenal adipose tissue transcriptome from IUGR fetuses with or without hypercatecholaminemia. IUGR was induced in sheep with maternal hyperthermia, and hypercatecholaminemia in IUGR was prevented with bilateral adrenal demedullation. Adipose tissue was collected from sham-operated control (CON) and IUGR fetuses and adrenal-demedullated control (CAD) and IUGR (IAD) fetuses. Norepinephrine concentrations were lower in IAD fetuses than in IUGR fetuses despite both being hypoxemic and hypoglycemic. In IUGR fetuses, perirenal adipose tissue mass relative to body mass was greater compared with the CON, adrenal-demedullated control, and IAD groups. Transcriptomic analysis identified 581 differentially expressed genes (DEGs) in CON vs IUGR adipose tissue and 193 DEGs in IUGR vs IAD adipose tissue. Integrated functional analysis of these 2 comparisons showed enrichment for proliferator-activated receptor signaling and metabolic pathways and identified adrenergic responsive genes. Within the adrenergic-regulated DEGs, we identified transcripts that regulate adipocyte proliferation and differentiation: adipogenesis regulatory factor, C/CCAAT/enhancer binding protein α, and sterol carrier protein 2. DEGs associated with the metabolic pathway included pyruvate dehydrogenase kinase 4, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 4, IGF-binding proteins (IGFBP-5 and IGFBP-7). Sex-specific expression differences were also found for adipogenesis regulatory factor, pyruvate dehydrogenase kinase 4, IGFBP5, and IGFBP7. These findings indicate that sustained adrenergic stimulation during IUGR leads to adipocyte hyperplasia with alterations in metabolism, proliferation, and preadipocyte differentiation pathways.

Cannabinoids Transmogrify Cancer Metabolic Phenotype via Epigenetic Reprogramming and a Novel CBD Biased G Protein-Coupled Receptor Signaling Platform

The concept of epigenetic reprogramming predicts long-term functional health effects. This reprogramming can be activated by exogenous or endogenous insults, leading to altered healthy and different disease states. The exogenous or endogenous changes that involve developing a roadmap of epigenetic networking, such as drug components on epigenetic imprinting and restoring epigenome patterns laid down during embryonic development, are paramount to establishing youthful cell type and health. This epigenetic landscape is considered one of the hallmarks of cancer. The initiation and progression of cancer are considered to involve epigenetic abnormalities and genetic alterations. Cancer epigenetics have shown extensive reprogramming of every component of the epigenetic machinery in cancer development, including DNA methylation, histone modifications, nucleosome positioning, non-coding RNAs, and microRNA expression. Endocannabinoids are natural lipid molecules whose levels are regulated by specific biosynthetic and degradative enzymes. They bind to and activate two primary cannabinoid receptors, type 1 (CB1) and type 2 (CB2), and together with their metabolizing enzymes, form the endocannabinoid system. This review focuses on the role of cannabinoid receptors CB1 and CB2 signaling in activating numerous receptor tyrosine kinases and Toll-like receptors in the induction of epigenetic landscape alterations in cancer cells, which might transmogrify cancer metabolism and epigenetic reprogramming to a metastatic phenotype. Strategies applied from conception could represent an innovative epigenetic target for preventing and treating human cancer. Here, we describe novel cannabinoid-biased G protein-coupled receptor signaling platforms (GPCR), highlighting putative future perspectives in this field.

Regulatory roles of noncoding RNAs in intervertebral disc degeneration as potential therapeutic targets (Review)

Intervertebral disc degeneration (IDD) is the leading cause of lower back pain, which is one of the primary factors that lead to disability and pose a serious economic burden. The key pathological processes involved are extracellular matrix degradation, autophagy, apoptosis, and inflammation of nucleus pulposus cells. Non-coding RNAs (ncRNAs), including microRNAs, long ncRNAs and circular RNAs, are key regulators of the aforementioned processes. ncRNAs are differentially expressed in tissues of the intervertebral disc between healthy individuals and patients and participate in the pathological progression of IDD via a complex pattern of gene regulation. However, the regulatory mechanisms of ncRNAs in IDD remain unclear. The present review summarizes the latest insights into the regulatory role of ncRNAs in IDD and sheds light on potentially novel therapeutic strategies for IDD that may be implemented in the future.

Circadian lncRNA ADIRF-AS1 binds PBAF and regulates renal clear cell tumorigenesis

We identify ADIRF-AS1 circadian long non-coding RNA (lncRNA). Deletion of ADIRF-AS1 in U2OS cells alters rhythmicity of clock-controlled genes and expression of extracellular matrix genes. ADIRF-AS1 interacts with all components of the PBAF (PBRM1/BRG1) complex in U2OS cells. Because PBRM1 is a tumor suppressor mutated in over 40% of clear cell renal carcinoma (ccRCC) cases, we evaluate ADIRF-AS1 in ccRCC cells. Reducing ADIRF-AS1 expression in ccRCC cells decreases expression of some PBAF-suppressed genes. Expression of these genes is partially rescued by PBRM1 loss, consistent with ADIRF-AS1 acting in part to modulate PBAF. ADIRF-AS1 expression correlates with survival in human ccRCC, particularly in PBRM1 wild-type, but not mutant, tumors. Loss of ADIRF-AS1 eliminates in vivo tumorigenesis, partially rescued by concurrent loss of PBRM1 only when co-injected with Matrigel, suggesting a PBRM1-independent function of ADIRF-AS1. Our findings suggest that ADIRF-AS1 functions partly through PBAF to regulate specific genes as a BMAL1-CLOCK-regulated, oncogenic lncRNA.

Insulin receptor substrate 1(IRS1) is related with lymph node metastases and prognosis in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the leading causes of cancer-related mortality globally with a high risk of lymph node metastasis (LNM). In this study, weighted gene co-expression network analysis (WGCNA) showed the identification of 10 modules among which the significant module (turquoise), including 1352 genes, was correlated with LNM. A group 52 overlapping differentially expressed genes (DEGs) was identified based on the comparison of turquoise module with GSE23400 and GSE20347 datasets. Using Ctyohubba plugin, we identified 7 hub genes (ACTG2, SORBS1, MYH11, CXCL12, CNN1, IRS1 and CXCL8). IRS1 displayed significant correlation with metastasis. The decreased expression of IRS1 was also a predictor of poor OS of ESCC patients whereas the hub genes namely ACTG2, MYH11, CXCL8, CXCL12, IRS1 and CNN1 were associated with RFS of ESCC patients. These findings suggest that the altered expression of these hub genes are associated with prognosis and thus can be used as potential biomarkers for ESCC. Moreover, immunohistochemical staining and cell functional experiments displayed that the overexpression of IRS1 was negatively associated with metastasis in ESCC. In general, our research revealed several novel genes in ESCC especially the association of IRS1 with LNM in ESCC, which could provide novel insights into the initiation and progression of ESCC.

Circular RNA UBAP2 facilitates the cisplatin resistance of triple-negative breast cancer via microRNA-300/anti-silencing function 1B histone chaperone/PI3K/AKT/mTOR axis

Circular RNAs (CircRNAs) have attracted increasing attention in the diagnosis and treatment of human cancers. CircUBAP2 has been identified to promote the progression of triple-negative breast cancer (TNBC), but the function of circUBAP2 in the cisplatin (DDP) resistance of TNBC remains obscure. Our investigation showed that circUBAP2 was significantly upregulated in DDP-resistant TNBC and TNBC sensitivity to DDP could be enhanced by silencing of circUBAP2. Moreover, circUBAP2 was revealed to be a ceRNA for miR-300 to upregulate the expression of anti-silencing function 1B histone chaperone (ASF1B). The effect of circUBAP2/miR-300/ASF1B axis on DDP resistance of TNBC was evaluated by rescue experiments, which demonstrated that circUBAP2 inhibited TNBC sensitivity to DDP through miR-300/ASF1B axis. Furthermore, it was discovered that ASF1B activated PI3K/AKT/mTOR signaling to facilitate the DDP resistance of TNBC cells. In summary, this research revealed a novel regulatory mechanism that circUBAP2 functioned as ceRNA of miR-300 to upregulate ASF1B, which further triggered the PI3K/AKT/mTOR (PAM) signaling to enhance the DDP resistance of TNBC.