Metabolic reprogramming: a bridge between aging and tumorigenesis

The Hallmarks of Precancer

Research on precancers, as defined as at-risk tissues and early lesions, is of high significance given the effectiveness of early intervention. We discuss the need for risk stratification to prevent overtreatment, an emphasis on the role of genetic and epigenetic aging when considering risk, and the importance of integrating macroenvironmental risk factors with molecules and cells in lesions and at-risk normal tissues for developing effective intervention and health policy strategies.

High-Dosage NMN Promotes Ferroptosis to Suppress Lung Adenocarcinoma Growth through the NAM-Mediated SIRT1-AMPK-ACC Pathway

BACKGROUND

Nicotinamide mononucleotide (NMN) is the physiological circulating NAD precursor thought to elevate the cellular level of NAD⁺ and to ameliorate various age-related diseases. An inseparable link exists between aging and tumorigenesis, especially involving aberrant energetic metabolism and cell fate regulation in cancer cells. However, few studies have directly investigated the effects of NMN on another major ageing-related disease: tumors.

METHODS

We conducted a series of cell and mouse models to evaluate the anti-tumor effect of high-dose NMN. Transmission electron microscopy and a Mito-FerroGreen-labeled immunofluorescence assay (Fe²⁺) were utilized to demonstrate ferroptosis. The metabolites of NAM were detected via ELISA. The expression of the proteins involved in the SIRT1-AMPK-ACC signaling were detected using a Western blot assay.

RESULTS

The results showed that high-dose NMN inhibits lung adenocarcinoma growth in vitro and in vivo. Excess NAM is produced through the metabolism of high-dose NMN, whereas the overexpression of NAMPT significantly decreases intracellular NAM content, which, in turn, boosts cell proliferation. Mechanistically, high-dose NMN promotes ferroptosis through NAM-mediated SIRT1-AMPK-ACC signaling.

CONCLUSIONS

This study highlights the tumor influence of NMN at high doses in the manipulation of cancer cell metabolism, providing a new perspective on clinical therapy in patients with lung adenocarcinoma.

Meta-hallmarks of aging and cancer

Both aging and cancer are characterized by a series of partially overlapping "hallmarks" that we subject here to a meta-analysis. Several hallmarks of aging (i.e., genomic instability, epigenetic alterations, chronic inflammation, and dysbiosis) are very similar to specific cancer hallmarks and hence constitute common "meta-hallmarks," while other features of aging (i.e., telomere attrition and stem cell exhaustion) act likely to suppress oncogenesis and hence can be viewed as preponderantly "antagonistic hallmarks." Disabled macroautophagy and cellular senescence are two hallmarks of aging that exert context-dependent oncosuppressive and pro-tumorigenic effects. Similarly, the equivalence or antagonism between aging-associated deregulated nutrient-sensing and cancer-relevant alterations of cellular metabolism is complex. The agonistic and antagonistic relationship between the processes that drive aging and cancer has bearings for the age-related increase and oldest age-related decrease of cancer morbidity and mortality, as well as for the therapeutic management of malignant disease in the elderly.

Immune senescence in non-small cell lung cancer management: therapeutic relevance, biomarkers, and mitigating approaches

INTRODUCTION

Lung cancer and mainly non-small cell lung cancer (NSCLC) still remain a prevalent malignancy worldwide despite sustained screening approaches. Furthermore, a significant proportion of the cases are diagnosed at advanced stages when conservative therapy is often unsuccessful. Cell senescence is an endogenous antitumor weapon but when it is upregulated exerts opposite activities favoring tumor metastasizing and poor response to therapy. However, little is known about this dangerous relationship between cell senescence and NSCLC outcome or on potential approaches to mitigate its unfavorable consequences.

AREAS COVERED

We discuss cell senescence focusing on immune senescence, its cell and humoral effectors (namely immune senescence associated secretory phenotype-iSASP), its impact on NSCLC outcome, and its biomarkers. Senotherapeutics as mitigating approaches are also considered based on the availability of experimental data pertinent to NSCLC.

EXPERT OPINION

Characterization of NSCLC subsets in which immune senescence is a risk factor for poor prognosis and poor therapeutic response might be very helpful in supporting the addition of senotherapeutics to conventional cancer therapy. This approach has the potential to improve disease outcome but more studies in this area are necessary.

The role of aging in cancer

Many cancers show an increase in incidence with age, and age is the biggest single risk factor for many cancers. However, the molecular basis of this relationship is poorly understood. Through a collection of review articles, our thematic issue discusses the link between aging and cancer in aspects including somatic mutations, proteostasis, mitochondria, metabolism, senescence, epigenetic regulation, immune regulation, DNA damage, and telomere function.