Aging and cancer最新文献

Background

Age is the most significant risk factor for ovarian cancer (OvCa), the deadliest gynecologic malignancy. Metastasizing OvCa cells adhere to the omentum, a peritoneal structure rich in collagen, adipocytes, and immune cells. Ultrastructural changes in the omentum and the omental collagen matrix with aging have not been evaluated.

Aim

The aim of this study was to test the hypothesis that age-related changes in collagen in the ovarian tumor microenvironment promote OvCa metastatic success in the aged host.

Methods/Results

Young (3–6 months) and aged mice (20–23 months) were used to study the role of aging in metastatic success. Intra-peritoneal (IP) injection of ID8Trp53^–/– OvCa cells showed enhanced IP dissemination in aged versus young mice. In vitro assays using purified collagen demonstrated reduced collagenolysis of aged fibers, as visualized using scanning electron microscopy (SEM) and quantified with a hydroxyproline release assay. Omental tumors in young and aged mice showed similar collagen deposition; however enhanced intra-tumoral collagen remodeling was seen in aged mice probed with a biotinylated collagen hybridizing peptide (CHP). In contrast, second harmonic generation (SHG) microscopy showed significant differences in collagen fiber structure and organization in omental tissue, and SEM demonstrated enhanced omental fenestration in aged omenta. Combined SHG and Alexa Fluor-CHP microscopy in vivo demonstrated that peri-tumoral collagen was remodeled more extensively in young mice. This collagen population represents truly aged host collagen, in contrast to intra-tumoral collagen that is newly synthesized, likely by cancer-associated fibroblasts.

Conclusions

Our results demonstrate that tumors in an aged host can grow with minimal collagen remodeling, while tumors in the young host must remodel peri-tumoral collagen to enable effective proliferation, providing a mechanism whereby age-induced ultrastructural changes in collagen and collagen-rich omenta establish a permissive premetastatic niche contributing to enhanced OvCa metastatic success in the aged host.

Background

Bladder cancer is one of the top 10 cancers diagnosed in Americans with a median age of 73. This is the patient population that tends to be older with multiple medical conditions, and previously described variability in treatment in the earlier stages of the disease. This study aimed to evaluate the first-line therapeutic choices for older adults newly diagnosed with advanced bladder cancer. In addition, this work evaluated predictors of response as well as the role of events of functional importance in relation to treatment assignment.

Methods

A population-based cohort study was conducted using the SEER-Medicare database of patients with advanced stage bladder cancer not eligible for curative intent therapy between 2010 and 2013. Patient groups of interest were compared via univariate and multivariate associations. Additionally, a latent class analysis was applied to identify classes with similar features in reference to events of functional importance—events linked to the maintenance or improvement of physical function status.

Results

Within the sample, we noted that a minority of patients received a standard cisplatin-containing regimen (14.77%) and a majority did not receive any chemotherapy (59.69%). Most patients were over age 75. The adjusted odds ratio of no chemo versus cisplatin in patients aged 76 and older compared to patients 66–75 was 6.61 (4.79–9.13; p < 0.0001). We applied latent class analysis methods to the dataset, and three classes demonstrated very low and moderate levels of functional events in the 12 months prior to a person's first outpatient visit for advanced bladder cancer care.

Conclusions

Patients with new diagnosis of advanced bladder cancer largely do not receive the recommended first-line systemic therapy of cisplatin chemotherapy, and a significant majority does not receive any treatment. When evaluating the association between class assignment and predictors of chemotherapy use, such as comorbidity and age, patients with “low usage overall” were more likely to receive chemotherapy. Yet even patients who received chemotherapy had some events of functional importance.

DNA molecules are subject to various lesions that can be detrimental to the cells. DNA damage response (DDR) pathways encompass a variety of mechanisms that cells employ in response to DNA damage. While DDR promotes genomic stability in normal cells, it also protects cancer cells from DNA lesions, particularly against exogenous DNA-damaging agents. Therefore, DDR pathways can be exploited to account for resistance to chemotherapy and radiotherapy and have the potential to be targeted in cancer treatment. Apart from the poly (ADP-ribose) polymerase (PARP) inhibitors used in BRCA-mutant cancers, other DDR inhibitors are being developed and tested in clinical trials. Based on the synthetic lethality theory, combination therapies utilizing DDR inhibitors have been explored and are currently undergoing clinical trials, with promising results in cancer treatment. Combination therapies typically employ a DDR inhibitor to sensitize cancer cells to traditional chemotherapeutic agents, radiotherapy, immunotherapy, and even PARP inhibitors. Herein, we focus on recent advances in DDR inhibitor-based combination therapies other than PARP inhibitors, explore the advantages and disadvantages of the strategies, and discuss the current challenges and future perspectives.

Introduction

Aging is the biggest cancer risk, and immune checkpoint (IC) inhibition (ICI) is a revolutionary cancer immunotherapy approach. Nonetheless, there are limited preclinical/clinical data regarding aging effects on ICI outcomes or age effects on IC expression in different organs or tumors.

Methods

Flow cytometry assessed IC on immune and non-immune cells in various organs in young and aged BL6 mice. Comparisons: aged versus young naïve WT versus interferon-γ^KO mice and WT challenged with B16F10 melanoma and treated with αPD-1 or αPD-L1 ICI. We co-cultured young and aged T cells and myeloid cells in vitro and used OMIQ analyses to test cell–cell interactions.

Results

αPD-1 ICI treated melanoma in young and aged hosts, whereas αPD-L1 ICI was only effective in young. We found considerable, previously undescribed age effects on expression of various IC molecules participating in the ICI treatment, including PD-1, PD-L1, PD-L2, and CD80, in distinct organs and in the tumor. These data help explain differential ICI efficacy in young and aged hosts. Host interferon-γ influenced age effects on IC expression in both directions depending on specific IC molecule and tissue. IC expression was further affected by tumor challenge on immune, non-immune, and tumor cells in tumor and other organs. In in vitro co-culture, αPD-1 versus αPD-L1 distinctly influenced polyclonal T cells in young versus aged, suggesting mechanisms for distinct age-related ICI outcomes.

Conclusion

Age affects IC expression on specific immune cells in an organ- and tissue-specific manner. ICs were generally higher on aged immune cells. High immune-cell PD-1 could help explain αPD-1 efficacy in aged. High co-expression of CD80 with PD-L1 on dendritic cells could help explain lack of αPD-L1 efficacy in aged hosts. Factors other than myeloid cells and interferon-γ also affect age-related IC expression and T cell function, meriting additional studies.

Cancer metastasis is the leading cause of cancer-related death. It is a complex, inefficient, and multistep process related to poor prognosis and high mortality of patients. Increasing evidence has shown that metabolic programming is a recognized hallmarker of cancer, plays a critical role in cancer metastasis. Metabolism alterations of glucose, lipid, and amino acid provide cancer cells with energy and substances for biosynthesis, maintain biofunctions and significantly affect proliferation, invasion, and metastasis of cancer cells. Tumor microenvironment (TME) is a complex system formed by varieties of cellular and noncellular elements. Nontumor cells in TME also undergo metabolic reprogramming or respond to metabolites to promote migration and invasion of cancer cells. A comprehensive understanding of the regulatory mechanism in metastasis from the metabolic reprogramming aspect is required to develop new therapeutic strategies combatting cancer metastasis. This review illustrates the metabolic reprogramming and interaction of cancer cells and nontumor cells in the TME, and the development of treatment strategies targeting metabolism alterations.

Background

Estimates indicate that nearly 8% of the over 500,000 survivors of childhood cancer living in the United States are frail in their fourth and fifth decades of life, a phenotype typically seen in geriatric populations. Participation in regular physical activity to improve physical fitness in healthy and diseased populations reduces risk for frail health by increasing physiologic reserve. However, physical activity may not have the same effects on fitness in childhood cancer survivors as it does among their peers with no cancer history.

Aims

This scoping review seeks to describe associations between physical activity, physical fitness, chronic disease, and mortality in childhood cancer survivors.

Methods

Relevant literature was identified through a comprehensive search in the PubMed, Web of Science, CINAHL, and Cochrane databases. A narrative synthesis was performed on observational studies that had physical activity or physical fitness clearly defined and compared with chronic disease outcomes.

Results

A total of 595 studies were screened, and results from 11 studies are presented. Childhood cancer survivors who participate in regular physical activity have improved markers of cardiovascular health, decreased risk of overt cardiovascular disease, and decreased risk of all-cause mortality compared to survivors who are not physically active. Childhood cancer survivors who are physically fit have increased neurocognition, and decreased risk of all-cause mortality compared to survivor's who are not fit. The differential effects of physical activity on fitness and health among childhood cancer survivors when compared to peers is potentially related to treatment exposures that damage cardiovascular tissue and impact regenerative potential.

Conclusion

Research is needed to determine the optimal timing, frequency, intensity, and duration of physical activity necessary to optimize fitness in childhood cancer survivors.

Background

Glioblastoma (GBM) is an aggressive, age-associated malignant glioma that contains populations of cancer stem cells. These glioma stem cells (GSCs) evade therapeutic interventions and repopulate tumors due to their existence in a slowly cycling quiescent state. Although aging is well known to increase cancer initiation, the extent to which the mechanisms supporting GSC tumorigenicity are related to physiological aging remains unknown.

Aims

Here, we investigate the transcriptional mechanisms by which Forkhead Box O3 (FOXO3), a transcriptional regulator that promotes healthy aging, affects GSC function and the extent to which FOXO3 transcriptional networks are dysregulated in aging and GBM.

Methods and results

We performed transcriptome analysis of clinical GBM tumors and observed that high FOXO3 activity is associated with gene expression signatures of stem cell quiescence, reduced oxidative metabolism, and improved patient outcomes. Consistent with these findings, we show that elevated FOXO3 activity significantly reduces the proliferation of GBM-derived GSCs. Using RNA-seq, we find that functional ablation of FOXO3 in GSCs rewires the transcriptional circuitry associated with metabolism, epigenetic stability, quiescence, and differentiation. Since FOXO3 has been implicated in healthy aging, we then investigated the extent to which it regulates common transcriptional programs in aging neural stem cells (NSCs) and GSCs. We uncover a shared transcriptional program and, most strikingly, find that FOXO3-regulated pathways are associated with altered mitochondrial functions in both aging and GBM.

Conclusions

This work identifies a FOXO-associated transcriptional program that correlates between GSCs and aging NSCs and is enriched for metabolic and stemness pathways connected with GBM and aging.

Aims

In patients with breast cancer, skin assessment is useful for the treatment and prevention of postoperative adverse effects of radiotherapy. This study was designed to clarify the long-term changes in the irradiated skin of patients after breast-conserving surgery using visual inspection and noninvasive imaging.

Methods

We compared changes in the irradiated skin over time between evaluations, based on visual inspection and noninvasive imaging in 31 patients receiving postmastectomy radiation therapy. The condition of the skin was evaluated by visual inspection of the thermogram, and analysis of skin surface temperature, intensity of erythema, intensity of melanin, and hydration level.

Results

Skin surface temperature remained higher at the irradiation site after 11 months, despite the absence of erythema per visual inspection. The intensity of erythema was higher at the irradiated site until 17–19 months after completion of irradiation. Similarly, the intensity of melanin tended to be higher at the irradiated site compared with the nonirradiated site until 17–19 months. The hydration level at the irradiated site was lower at 6 months but recovered to match the nonirradiated site at 11–13 months. Impaired skin conditions assessed by noninvasive objective procedures persist longer than the assessment made by visual inspection.

Conclusions

Adverse effects should be treated or prevented in the long term in patients receiving postmastectomy radiation therapy.