A feedback loop between NONHSAT024276 and PTBP1 inhibits tumor progression and glycolysis in HCC by increasing the PKM1/PKM2 ratio

Involvement of lncRNAs in the regulation of aerobic glycolysis in hepatocellular carcinoma: Main functions, regulatory mechanisms and potential therapeutic implications (Review)

Even under aerobic conditions, tumor cells can reprogram their metabolism to preferentially metabolize glucose into lactic acid. This abnormal metabolic pattern, known as the 'Warburg' effect or aerobic glycolysis, promotes cancer progression. Long non‑coding RNAs (lncRNAs) are RNAs that are >200 nucleotides in length and do not have protein‑coding capabilities. However, these RNAs play a key role in tumor development. There is increasing evidence to indicate that lncRNAs regulate glucose metabolism in tumor cells by affecting metabolic enzymes and some signaling pathways, thereby regulating the occurrence and progression of hepatocellular carcinoma (HCC). Therefore, it is crucial to understand which lncRNAs play a regulatory role in HCC glycolysis and to determine the related molecular mechanisms. The present review summarized and discussed the functions of lncRNAs, focusing on the regulatory mechanisms of lncRNAs in the process of glycolysis in HCC. In addition, the present review suggests the importance of lncRNAs as future therapeutic targets for antitumor cell metabolism.

USP46 enhances tamoxifen resistance in breast cancer cells by stabilizing PTBP1 to facilitate glycolysis

Tamoxifen (TAM) is the primary drug for treating estrogen receptor alpha-positive (ER+) breast cancer (BC). However, resistance to TAM can develop in some patients, limiting its therapeutic efficacy. The ubiquitin-specific protease (USP) family has been associated with the development, progression, and drug resistance of various cancers. To explore the role of USPs in TAM resistance in BC, we used qRT-PCR to compare USP expression between TAM-sensitive (MCF-7 and T47D) and TAM-resistant cells (MCF-7R and T47DR). We then modulated USP46 expression and examined its impact on cell proliferation, drug resistance (via CCK-8 and EdU experiments), glycolysis levels (using a glycolysis detection assay), protein interactions (confirmed by co-IP), and protein changes (analyzed through Western blotting). Our findings revealed that USP46 was significantly overexpressed in TAM-resistant BC cells, leading to the inhibition of the ubiquitin degradation of polypyrimidine tract-binding protein 1 (PTBP1). Overexpression of PTBP1 increased the PKM2/PKM1 ratio, promoted glycolysis, and intensified TAM resistance in BC cells. Knockdown of USP46 induced downregulation of PTBP1 protein by promoting its K48-linked ubiquitination, resulting in a decreased PKM2/PKM1 ratio, reduced glycolysis, and heightened TAM sensitivity in BC cells. In conclusion, this study highlights the critical role of the USP46/PTBP1/PKM2 axis in TAM resistance in BC. Targeted therapy against USP46 may represent a promising strategy to improve the prognosis of TAM-resistant patients.

Mitochondria: It is all about energy

Mitochondria play a key role in both health and disease. Their function is not limited to energy production but serves multiple mechanisms varying from iron and calcium homeostasis to the production of hormones and neurotransmitters, such as melatonin. They enable and influence communication at all physical levels through interaction with other organelles, the nucleus, and the outside environment. The literature suggests crosstalk mechanisms between mitochondria and circadian clocks, the gut microbiota, and the immune system. They might even be the hub supporting and integrating activity across all these domains. Hence, they might be the (missing) link in both health and disease. Mitochondrial dysfunction is related to metabolic syndrome, neuronal diseases, cancer, cardiovascular and infectious diseases, and inflammatory disorders. In this regard, diseases such as cancer, Alzheimer's, Parkinson's, amyotrophic lateral sclerosis (ALS), chronic fatigue syndrome (CFS), and chronic pain are discussed. This review focuses on understanding the mitochondrial mechanisms of action that allow for the maintenance of mitochondrial health and the pathways toward dysregulated mechanisms. Although mitochondria have allowed us to adapt to changes over the course of evolution, in turn, evolution has shaped mitochondria. Each evolution-based intervention influences mitochondria in its own way. The use of physiological stress triggers tolerance to the stressor, achieving adaptability and resistance. This review describes strategies that could recover mitochondrial functioning in multiple diseases, providing a comprehensive, root-cause-focused, integrative approach to recovering health and treating people suffering from chronic diseases.