Androgen-Dependent Prostate Cancer Cells Reprogram Their Metabolic Signature upon GLUT1 Upregulation by Manganese Superoxide Dismutase

Basal and AT2 cells promote IPF-lung cancer co-occurrence via EMT: Single-cell analysis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrotic interstitial lung disease. With IPF, the probability of complication with lung cancer (LCA) increases considerably, and the prognosis is worse than that of simple IPF. To understand the pathological mechanisms and molecular pathways shared by these two diseases, we used the single-cell analysis from the Gene Expression Omnibus (GEO) database, and find that basal cells (BCs) and alveolar type 2 cells (AT2 cells) are important components of lung epithelial cells. Changes in molecular pathways in BCs and AT2 cells may be involved in the common pathogenesis of IPF and LCA. KRT17 and S100A14 in BCs may promote the IPF co-occurrence with LCA by mediating the EMT. WFDC2 and KRT19 may be the elements in AT2 cells that activate the EMT process to promote IPF co-occurrence with LCA. In both IPF and LCA, FN1-WNT axis may be involved in the interaction between BCs and AT2 cells. Importantly, the results of immunofluorescence colocalization experiments on tissue samples from patients with IPF and LCA were consistent with these conclusions. Basal-macrophage interactions may have also induced the IPF co-occurrence with LCA via the CYBA-ERK1/2 axis. The regulation of M2 macrophage polarization by JUN/SOD2-glycolysis axis may therefore be involved in the co-morbidity mechanism of IPF and LCA. Therefore, our results suggest that molecular changes in BCs, AT2 cells and macrophages may play important roles in the pathogenesis of IPF co-occurrence with LCA, and the cellular interactions between these cells may be critical for the progression of both diseases.

GPCR-Gα13 Involvement in Mitochondrial Function, Oxidative Stress, and Prostate Cancer

Gα13 and Gα12, encoded by the GNA13 and GNA12 genes, respectively, are members of the G12 family of Gα proteins that, along with their associated Gβγ subunits, mediate signaling from specific G protein-coupled receptors (GPCRs). Advanced prostate cancers have increased expression of GPCRs such as CXC Motif Chemokine Receptor 4 (CXCR4), lysophosphatidic acid receptor (LPAR), and protease activated receptor 1 (PAR-1). These GPCRs signal through either the G12 family, or through Gα13 exclusively, often in addition to other G proteins. The effect of Gα13 can be distinct from that of Gα12, and the role of Gα13 in prostate cancer initiation and progression is largely unexplored. The oncogenic effect of Gα13 on cell migration and invasion in prostate cancer has been characterized, but little is known about other biological processes such as mitochondrial function and oxidative stress. Current knowledge on the link between Gα13 and oxidative stress is based on animal studies in which GPCR-Gα13 signaling decreased superoxide levels, and the overexpression of constitutively active Gα13 promoted antioxidant gene activation. In human samples, mitochondrial superoxide dismutase 2 (SOD2) correlates with prostate cancer risk and prognostic Gleason grade. However, overexpression of SOD2 in prostate cancer cells yielded conflicting results on cell growth and survival under basal versus oxidative stress conditions. Hence, it is necessary to explore the effect of Gα13 on prostate cancer tumorigenesis, as well as the effect of Gα13 on SOD2 in prostate cancer cell growth under oxidative stress conditions.

Transcending frontiers in prostate cancer: the role of oncometabolites on epigenetic regulation, CSCs, and tumor microenvironment to identify new therapeutic strategies

Prostate cancer, as one of the most prevalent malignancies in males, exhibits an approximate 5-year survival rate of 95% in advanced stages. A myriad of molecular events and mutations, including the accumulation of oncometabolites, underpin the genesis and progression of this cancer type. Despite growing research demonstrating the pivotal role of oncometabolites in supporting various cancers, including prostate cancer, the root causes of their accumulation, especially in the absence of enzymatic mutations, remain elusive. Consequently, identifying a tangible therapeutic target poses a formidable challenge. In this review, we aim to delve deeper into the implications of oncometabolite accumulation in prostate cancer. We center our focus on the consequential epigenetic alterations and impacts on cancer stem cells, with the ultimate goal of outlining novel therapeutic strategies.

CDK13 promotes lipid deposition and prostate cancer progression by stimulating NSUN5-mediated m5C modification of ACC1 mRNA

Cyclin-dependent kinases (CDKs) regulate cell cycle progression and the transcription of a number of genes, including lipid metabolism-related genes, and aberrant lipid metabolism is involved in prostate carcinogenesis. Previous studies have shown that CDK13 expression is upregulated and fatty acid synthesis is increased in prostate cancer (PCa). However, the molecular mechanisms linking CDK13 upregulation and aberrant lipid metabolism in PCa cells remain largely unknown. Here, we showed that upregulation of CDK13 in PCa cells increases the fatty acyl chains and lipid classes, leading to lipid deposition in the cells, which is positively correlated with the expression of acetyl-CoA carboxylase (ACC1), the first rate-limiting enzyme in fatty acid synthesis. Gain- and loss-of-function studies showed that ACC1 mediates CDK13-induced lipid accumulation and PCa progression by enhancing lipid synthesis. Mechanistically, CDK13 interacts with RNA-methyltransferase NSUN5 to promote its phosphorylation at Ser327. In turn, phosphorylated NSUN5 catalyzes the m5C modification of ACC1 mRNA, and then the m5C-modified ACC1 mRNA binds to ALYREF to enhance its stability and nuclear export, thereby contributing to an increase in ACC1 expression and lipid deposition in PCa cells. Overall, our results disclose a novel function of CDK13 in regulating the ACC1 expression and identify a previously unrecognized CDK13/NSUN5/ACC1 pathway that mediates fatty acid synthesis and lipid accumulation in PCa cells, and targeting this newly identified pathway may be a novel therapeutic option for the treatment of PCa.

Cell-Type-Specific Signalling Networks Impacted by Prostate Epithelial-Stromal Intercellular Communication

Prostate cancer is the second most common cause of cancer death in males. A greater understanding of cell signalling events that occur within the prostate cancer tumour microenvironment (TME), for example, between cancer-associated fibroblasts (CAFs) and prostate epithelial or cancer cells, may identify novel biomarkers and more effective therapeutic strategies for this disease. To address this, we used cell-type-specific labelling with amino acid precursors (CTAP) to define cell-type-specific (phospho)proteomic changes that occur when prostate epithelial cells are co-cultured with normal patient-derived prostate fibroblasts (NPFs) versus matched CAFs. We report significant differences in the response of BPH-1 benign prostate epithelial cells to CAF versus NPF co-culture. Pathway analysis of proteomic changes identified significant upregulation of focal adhesion and cytoskeleton networks, and downregulation of metabolism pathways, in BPH-1 cells cultured with CAFs. In addition, co-cultured CAFs exhibited alterations in stress, DNA damage, and cytoskeletal networks. Functional validation of one of the top differentially-regulated proteins in BPH-1 cells upon CAF co-culture, transglutaminase-2 (TGM2), demonstrated that knockdown of this protein significantly reduced the proliferation and migration of prostate epithelial cells. Overall, this study provides novel insights into intercellular communication in the prostate cancer TME that may be exploited to improve patient management.

NEK6 Regulates Redox Balance and DNA Damage Response in DU-145 Prostate Cancer Cells

NEK6 is a central kinase in developing castration-resistant prostate cancer (CRPC). However, the pathways regulated by NEK6 in CRPC are still unclear. Cancer cells have high reactive oxygen species (ROS) levels and easily adapt to this circumstance and avoid cell death by increasing antioxidant defenses. We knocked out the NEK6 gene and evaluated the redox state and DNA damage response in DU-145 cells. The knockout of NEK6 decreases the clonogenic capacity, proliferation, cell viability, and mitochondrial activity. Targeting the NEK6 gene increases the level of intracellular ROS; decreases the expression of antioxidant defenses (SOD1, SOD2, and PRDX3); increases JNK phosphorylation, a stress-responsive kinase; and increases DNA damage markers (p-ATM and γH2AX). The exogenous overexpression of NEK6 also increases the expression of these same antioxidant defenses and decreases γH2AX. The depletion of NEK6 also induces cell death by apoptosis and reduces the antiapoptotic Bcl-2 protein. NEK6-lacking cells have more sensitivity to cisplatin. Additionally, NEK6 regulates the nuclear localization of NF-κB2, suggesting NEK6 may regulate NF-κB2 activity. Therefore, NEK6 alters the redox balance, regulates the expression of antioxidant proteins and DNA damage, and its absence induces the death of DU-145 cells. NEK6 inhibition may be a new strategy for CRPC therapy.

Insights into Manganese Superoxide Dismutase and Human Diseases

Redox equilibria and the modulation of redox signalling play crucial roles in physiological processes. Overproduction of reactive oxygen species (ROS) disrupts the body's antioxidant defence, compromising redox homeostasis and increasing oxidative stress, leading to the development of several diseases. Manganese superoxide dismutase (MnSOD) is a principal antioxidant enzyme that protects cells from oxidative damage by converting superoxide anion radicals to hydrogen peroxide and oxygen in mitochondria. Systematic studies have demonstrated that MnSOD plays an indispensable role in multiple diseases. This review focuses on preclinical evidence that describes the mechanisms of MnSOD in diseases accompanied with an imbalanced redox status, including fibrotic diseases, inflammation, diabetes, vascular diseases, neurodegenerative diseases, and cancer. The potential therapeutic effects of MnSOD activators and MnSOD mimetics are also discussed. Targeting this specific superoxide anion radical scavenger may be a clinically beneficial strategy, and understanding the therapeutic role of MnSOD may provide a positive insight into preventing and treating related diseases.