PFKP phenotype in lung cancer: prognostic potential and beyond

Silencing circLDLRAD3 Inhibits Lung Cancer Progression by Regulating the miR-497-5p/PFKP Axis

PURPOSE

Lung cancer is one of the leading causes of death worldwide. Recent studies have shown that circular RNAs are dysregulated in a variety of cancers, but the mechanism in lung cancer is still indistinct. In our work, we explored the action mechanism of circLDLRAD3 in lung cancer.

METHODS

The abundance of circLDLRAD3, microRNA-497-5p (miR-497-5p) and platelet-type PFK (PFKP) was measured by real-time quantitative polymerase chain reaction (RT-qPCR) in lung cancer. Meanwhile, the level of PFKP was quantified by western blot. Cell counting kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU) assay, transwell assay, wound healing assay, flow cytometry, western blot, immunohistochemical (IHC) assay and glycolysis metabolism analysis were performed for functional analyses. Furthermore, the interplay between miR-497-5p and circLDLRAD3 or FKPF was detected by the dual-luciferase reporter and RNA Immunoprecipitation (RIP) assays. Eventually, the in vivo experiments were applied to measure the role of circLDLRAD3.

RESULT

The levels of circLDLRAD3 and PFKP were increased. Silencing circLDLRAD3 inhibited cell viability, proliferation, migration, invasion and glycolysis metabolism and promoted cell apoptosis in lung cancer cells. In mechanism, circLDLRAD3 regulated PFKP level as a miR-497-5p sponge. MiR-497-5p suppressed the progression of lung cancer by inhibiting PFKP. In addition, circLDLRAD3 knockdown also inhibited tumor growth in vivo.

CONCLUSION

CircLDLRAD3 promoted the development of lung cancer through increasing PFKP expression by regulating miR-497-5p, which also provided a potential targeted therapy for lung cancer treatment.

Catalyst-free late-stage functionalization to assemble α-acyloxyenamide electrophiles for selectively profiling conserved lysine residues

Covalent probes coupled with chemical proteomics represent a powerful method for investigating small molecule and protein interactions. However, the creation of a reactive warhead within various ligands to form covalent probes has been a major obstacle. Herein, we report a convenient and robust process to assemble a unique electrophile, an α-acyloxyenamide, through a one-step late-stage coupling reaction. This procedure demonstrates remarkable tolerance towards other functional groups and facilitates ligand-directed labeling in proteins of interest. The reactive group has been successfully incorporated into a clinical drug targeting the EGFR L858R mutant, erlotinib, and a pan-kinase inhibitor. The resulting probes have been shown to be able to covalently engage a lysine residue proximal to the ATP-binding pocket of the EGFR L858R mutant. A series of active sites, and Mg2+, ATP-binding sites of kinases, such as K33 of CDK1, CDK2, CDK5 were detected. This is the first report of engaging these conserved catalytic lysine residues in kinases with covalent inhibition. Further application of this methodology to natural products has demonstrated its success in profiling ligandable conserved lysine residues in whole proteome. These findings offer insights for the development of new targeted covalent inhibitors (TCIs).

PFKP is a prospective prognostic, diagnostic, immunological and drug sensitivity predictor across pan-cancer

Phosphofructokinase, platelet (PFKP) is a rate-limiting enzyme of glycolysis that plays a decisive role in various human physio-pathological processes. PFKP has been reported to have multiple functions in different cancer types, including lung cancer and breast cancer. However, no systematic pancancer analysis of PFKP has been performed; this type of analysis could elucidate the clinical value of PFKP in terms of diagnosis, prognosis, drug sensitivity, and immunological correlation. Systematic bioinformation analysis of PFKP was performed based on several public datasets, including The Cancer Genome Atlas (TCGA), Cancer Cell Line Encyclopedia (CCLE), Genotype-Tissue Expression Project (GTEx), and Human Protein Atlas (HPA). Prospective carcinogenesis of PFKP across cancers was estimated by expression analysis, effect on patient prognosis, diagnosis significance evaluation, and immunity regulation estimation. Then, pancancer functional enrichment of PFKP was also assessed through its effect on the signaling score and gene expression profile. Finally, upstream expression regulation of PFKP was explored by promoter DNA methylation and transcription factor (TF) prediction. Our analysis revealed that high expression of PFKP was found in most cancer types. Additionally, a high level of PFKP displayed a significant correlation with poor prognosis in patients across cancers. The diagnostic value of PFKP was performed based on its positive correlation with programmed cell death-ligand 1 (PD-L1). We also found an obvious immune-regulating effect of PFKP in most cancer types. PFKP also had a strong negative correlation with several cancer drugs. Finally, ectopic expression of PFKP may depend on DNA methylation and several predicated transcription factors, including the KLF (KLF transcription factor) and Sp (Sp transcription factor) families. This pancancer analysis revealed that a high expression level of PFKP might be a useful biomarker and predictor in most cancer types. Additionally, the performance of PFKP across cancers also suggested its meaningful role in cancer immunity regulation, even in immunotherapy and drug resistance. Overall, PFKP might be explored as an auxiliary monitor for pancancer early prognosis and diagnosis.

The strategic roles of four enzymes in the interconnection between metabolism and oncogene activation in non-small cell lung cancer: Therapeutic implications

NSCLC is the leading cause of cancer mortality and represents a major challenge in cancer therapy. Intrinsic and acquired anticancer drug resistance are promoted by hypoxia and HIF-1α. Moreover, chemoresistance is sustained by the activation of key signaling pathways (such as RAS and its well-known downstream targets PI3K/AKT and MAPK) and several mutated oncogenes (including KRAS and EGFR among others). In this review, we highlight how these oncogenic factors are interconnected with cell metabolism (aerobic glycolysis, glutaminolysis and lipid synthesis). Also, we stress the key role of four metabolic enzymes (PFK1, dimeric-PKM2, GLS1 and ACLY), which promote the activation of these oncogenic pathways in a positive feedback loop. These four tenors orchestrating the coordination of metabolism and oncogenic pathways could be key druggable targets for specific inhibition. Since PFK1 appears as the first tenor of this orchestra, its inhibition (and/or that of its main activator PFK2/PFKFB3) could be an efficacious strategy against NSCLC. Citrate is a potent physiologic inhibitor of both PFK1 and PFKFB3, and NSCLC cells seem to maintain a low citrate level to sustain aerobic glycolysis and the PFK1/PI3K/EGFR axis. Awaiting the development of specific non-toxic inhibitors of PFK1 and PFK2/PFKFB3, we propose to test strategies increasing citrate levels in NSCLC tumors to disrupt this interconnection. This could be attempted by evaluating inhibitors of the citrate-consuming enzyme ACLY and/or by direct administration of citrate at high doses. In preclinical models, this "citrate strategy" efficiently inhibits PFK1/PFK2, HIF-1α, and IGFR/PI3K/AKT axes. It also blocks tumor growth in RAS-driven lung cancer models, reversing dedifferentiation, promoting T lymphocytes tumor infiltration, and increasing sensitivity to cytotoxic drugs.

FDX1 can Impact the Prognosis and Mediate the Metabolism of Lung Adenocarcinoma

Background: Lung cancer has emerged as one of the most common cancers in recent years. The mitochondrial electron transport chain (ETC) is closely connected with metabolic pathways and inflammatory response. However, the influence of ETC-associated genes on the tumor immune response and the pathogenesis of lung cancer is not clear and needs further exploration.

Methods: The RNA-sequencing transcriptome and clinical characteristic data of LUAD were downloaded from the Cancer Genome Atlas (TCGA) database. The LASSO algorithm was used to build the risk signature, and the prediction model was evaluated by the survival analysis and receiver operating characteristic curve. We explored the function of FDX1 through flow cytometry, molecular biological methods, and liquid chromatography–tandem mass spectrometry/mass spectrometry (LC–MS/MS).

Results: 12 genes (FDX1, FDX2, LOXL2, ASPH, GLRX2, ALDH2, CYCS, AKR1A1, MAOB, RDH16, CYBB, and CYB5A) were selected to build the risk signature, and the risk score was calculated with the coefficients from the LASSO algorithm. The 1-year, 3-year, and 5-year area under the curve (AUC) of ROC curves of the dataset were 0.7, 0.674, and 0.692, respectively. Univariate Cox analysis and multivariate Cox regression analysis indicated that the risk signature is an independent risk factor for LUAD patients. Among these genes, we focused on the FDX1 gene, and we found that knockdown of FDX1 neither inhibited tumor cell growth nor did it induce apoptosis or abnormal cell cycle distribution. But FDX1 could promote the ATP production. Furthermore, our study showed that FDX1 was closely related to the glucose metabolism, fatty acid oxidation, and amino acid metabolism.

Conclusion: Collectively, this study provides new clues about carcinogenesis induced by ETC-associated genes in LUAD and paves the way for finding potential targets of LUAD.

Silencing PFKP restrains the stemness of hepatocellular carcinoma cells

BACKGROUND

Glycolysis reprogramming is deeply involved in the progression of hepatocellular carcinoma (HCC), in which HCC cells with stemness traits play important roles as well. Thus, whether platelet isoform of phosphofructokinase 1 (PFKP), a rate-limiting enzyme in glycolysis, contributes to the maintenance of stemness of HCC cells is worth investigation.

METHODS

PFKP levels were compared between human hepatocellular carcinoma and adjacent normal tissues by Western blotting and immunohistochemistry. The relationship between PFKP expression and clinic pathological features was also analyzed. Furthermore, the colony formation capabilities and the levels of stemness markers (ALDH1, CD44, CD133, Sox-2) as well as β-catenin were compared between HCC cells either undergoing PFKP silencing or overexpression.

RESULTS

PFKP levels were higher in HCC as compared to normal hepatic tissues. Silencing PFKP decreased HCC proliferation, colony formation capabilities, and levels of stemness markers and β-catenin; whereas overexpressing PFKP demonstrated the opposite effects.

CONCLUSION

PFKP promoted HCC proliferation and contributed to the maintenance of HCC stemness. Silencing PFKP could restrain the stemness of HCC, suggesting that PFKP may be a potential therapeutic target for HCC treatment.