Hsa_circ_0000073 promotes lipid synthesis of osteosarcoma through hsa-miR-1184/ FADS2 pathway

Circ_0124346 facilitates cell proliferation of pancreatic adenocarcinoma cells by regulating lipid metabolism via miR-223-3p/ACSL3 axis

BACKGROUND

Both lipid metabolism and cyclic RNAs (circRNAs) have been found to be involved in pancreatic adenocarcinoma (PAAD) progression, but the relationship between lipid metabolism and circRNAs remains unclear.

METHODS

The expression levels of miR-223-3p, circ_0124346, and acyl-CoA synthetase long chain family member 3 (ACSL3) were determined through qRT-PCR and Western blot analysis. Cell proliferation was evaluated using the CCK-8 and EdU incorporation assays. Cholesterol (CH) and triglyceride (TG) levels were quantified using relevant kits. The relationships between miR-223-3p and circ_0124346 or ACSL3 mRNA were examined by bioinformatics analysis, luciferase reporter, RNA-RNA pull-down, and RIP assays.

RESULTS

We observed a significant elevation in circ_0124346 expression in both pancreatic adenocarcinoma (PAAD) tissues and cell lines, and its expression level was shown to be correlated with tumor size. Circ_0124346 stimulated cell proliferation and facilitated lipid synthesis in PAAD cells. Additionally, we found that circ_0124346 functioned as a sponge for miR-223-3p, preventing miR-223-3p's binding to the 3'-UTR of ACSL3 mRNA, which subsequently led to an elevation in ACSL3 expression and promoted lipid synthesis. Accordingly, circ_0124346 knockdown resulted in a significant decrease in lipid synthesis and cell proliferation in PAAD cells, with partial reversal of these effects achieved via inhibiting miR-223-3p or overexpressing ACSL3.

CONCLUSION

Our study demonstrated that circ_0124346 regulates lipid metabolism in PAAD cells via the miR-223-3p/ACSL3 axis, suggesting that targeting circ_0124346 may serve as a potential strategy for treating PAAD and assisting in its diagnosis.

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.

Circ_0007534 promotes cholangiocarcinoma stemness and resistance to anoikis through DDX3X-mediated positive feedback regulation of parental gene DDX42

Cholangiocarcinoma (CCA) is a malignancy with an extremely poor prognosis, and much remains unknown about its pathogenesis and treatment modalities. Circular RNA (circRNA) has been proven to play regulatory roles in various tumorigenesis, yet its potential function and mechanism in cholangiocarcinoma require further investigation. This study is the first to identify the aberrant expression and functional role of a novel circRNA, circ_0007534, derived from the DDX42 gene, in cholangiocarcinoma. Compared to the normal control group, the expression of circ_0007534 was significantly elevated in the tissues and cells with CCA and that high expression correlated with lymph node invasion and poor prognosis. Functional experiments indicated that downregulating circ_0007534 markedly inhibited the proliferation, migration, invasion, stemness, and anti-anoikis ability of CCA cells, as well as the tumor growth and liver and lung metastasis in nude mice. Mechanistic studies revealed that DDX42, as the parent gene of circ_0007534, can mutually regulate each other's expression. Predominantly located in the cytoplasm, circ_0007534 can form a complex with the RNA-binding protein DDX3X, which enhances the stability of DDX42 mRNA, thereby upregulating the expression of DDX42. This creates a positive feedback loop among the three, collectively promoting the progression of cholangiocarcinoma. In conclusion, this study sheds light on the pivotal role and molecular mechanism of circ_0007534 in the development of CCA, offering potential new targets for early diagnosis and treatment.

Lipid metabolism-derived FAAH is a sensitive marker for the prognosis and immunotherapy of osteosarcoma patients

Lipid metabolism in cancer refers to the alterations in how cancer cells process and utilize lipids, a type of fat molecule. It was investigated how lipid metabolism relates to osteosarcoma. Genes relevant to lipid metabolism were gathered to create lipid metabolism-associated clusters and locate the dangerous marker. We investigated FAAH's prognostic significance, route annotation, immunotherapy response, and medication prediction. Besides, FAAH is proven to be a potent, dangerous marker that may promote growth and migration and inhibit the apoptosis of osteosarcoma. FAAH exhibits higher expression levels in tumor tissues as compared to normal tissues. In conclusion, FAAH is identified in this work as a potentially dangerous gene and immunotherapy determinant. This study requires more investigation to determine how FAAH influences the immune response in osteosarcoma.

LncRNAs-circRNAs as Rising Epigenetic Binary Superstars in Regulating Lipid Metabolic Reprogramming of Cancers

As one of novel hallmarks of cancer, lipid metabolic reprogramming has recently been becoming fascinating and widely studied. Lipid metabolic reprogramming in cancer is shown to support carcinogenesis, progression, distal metastasis, and chemotherapy resistance by generating ATP, biosynthesizing macromolecules, and maintaining appropriate redox status. Notably, increasing evidence confirms that lipid metabolic reprogramming is under the control of dysregulated non-coding RNAs in cancer, especially lncRNAs and circRNAs. This review highlights the present research findings on the aberrantly expressed lncRNAs and circRNAs involved in the lipid metabolic reprogramming of cancer. Emphasis is placed on their regulatory targets in lipid metabolic reprogramming and associated mechanisms, including the clinical relevance in cancer through lipid metabolism modulation. Such insights will be pivotal in identifying new theranostic targets and treatment strategies for cancer patients afflicted with lipid metabolic reprogramming.