Positioning determines function: Wandering PKM2 performs different roles in tumor cells

The regulatory roles of RNA-binding proteins in the tumour immune microenvironment of gastrointestinal malignancies

The crosstalk between the tumour immune microenvironment (TIME) and tumour cells promote immune evasion and resistance to immunotherapy in gastrointestinal (GI) tumours. Post-transcriptional regulation of genes is pivotal to GI tumours progression, and RNA-binding proteins (RBPs) serve as key regulators via their RNA-binding domains. RBPs may exhibit either anti-tumour or pro-tumour functions by influencing the TIME through the modulation of mRNAs and non-coding RNAs expression, as well as post-transcriptional modifications, primarily N6-methyladenosine (m6A). Aberrant regulation of RBPs, such as HuR and YBX1, typically enhances tumour immune escape and impacts prognosis of GI tumour patients. Further, while targeting RBPs offers a promising strategy for improving immunotherapy in GI cancers, the mechanisms by which RBPs regulate the TIME in these tumours remain poorly understood, and the therapeutic application is still in its early stages. This review summarizes current advances in exploring the roles of RBPs in regulating genes expression and their effect on the TIME of GI tumours, then providing theoretical insights for RBP-targeted cancer therapies.

The potential roles of PKM2 in cerebrovascular diseases

Pyruvate kinase M2 (PKM2), a key enzyme involved in glycolysis,plays an important role in regulating cell metabolism and growth under different physiological conditions. PKM2 has been intensively investigated in multiple cancer diseases. Recent years, many studies have found its pivotal role in cerebrovascular diseases (CeVDs), the disturbances in intracranial blood circulation. CeVDs has been confirmed to be closely associated with oxidative stress (OS), mitochondrial dynamics, systemic inflammation, and local neuroinflammation in the brain. It has further been revealed that PKM2 exerts various biological functions in the regulation of energy supply, OS, inflammatory responses, and mitochondrial dysfunction. The roles of PKM2 are closely related to its different isoforms, expression levels in subcellular localization, and post-translational modifications. Therefore, summarizing the roles of PKM2 in CeVDs will help further understanding the molecular mechanisms of CeVDs. In this review, we illustrate the characteristics of PKM2, the regulated PKM2 expression, and the biological roles of PKM2 in CeVDs.

Exploring the diverse role of pyruvate kinase M2 in cancer: Navigating beyond glycolysis and the Warburg effect

Pyruvate Kinase M2, a key enzyme in glycolysis, has garnered significant attention in cancer research due to its pivotal role in the metabolic reprogramming of cancer cells. Originally identified for its association with the Warburg effect, PKM2 has emerged as a multifaceted player in cancer biology. The functioning of PKM2 is intricately regulated at multiple levels, including controlling the gene expression via various transcription factors and non-coding RNAs, as well as adding post-translational modifications that confer distinct functions to the protein. Here, we explore the diverse functions of PKM2, encompassing newly emerging roles in non-glycolytic metabolic regulation, immunomodulation, inflammation, DNA repair and mRNA processing, beyond its canonical role in glycolysis. The ever-expanding list of its functions has recently grown to include roles in subcellular compartments such as the mitochondria and extracellular milieu as well, all of which make PKM2 an attractive drug target in the pursuit of therapeutics for cancer.