Role of Regular Physical Exercise in Tumor Vasculature: Favorable Modulator of Tumor Milieu

Beneficial effects of physical exercise on cognitive-behavioral impairments and brain-derived neurotrophic factor alteration in the limbic system induced by neurodegeneration

Neurodegenerative diseases (NDDs) are a class of neurological disorders marked by the progressive loss of neurons that afflict millions of people worldwide. These illnesses affect brain connection, impairing memory, cognition, behavior, sensory perception, and motor function. Alzheimer's, Parkinson's, and Huntington's diseases are examples of common NDDs, which frequently include the buildup of misfolded proteins. Cognitive-behavioral impairments are early markers of neurodevelopmental disorders, emphasizing the importance of early detection and intervention. Neurotrophins such as brain-derived neurotrophic factor (BDNF) are critical for neuron survival and synaptic plasticity, which is required for learning and memory. NDDs have been associated with decreased BDNF levels. Physical exercise, a non-pharmacological intervention, benefits brain health by increasing BDNF levels, lowering cognitive deficits, and slowing brain degradation. Exercise advantages include increased well-being, reduced depression, improved cognitive skills, and neuroprotection by lowering amyloid accumulation, oxidative stress, and neuroinflammation. This study examines the effects of physical exercise on cognitive-behavioral deficits and BDNF levels in the limbic system impacted by neurodegeneration. The findings highlight the necessity of including exercise into NDD treatment to improve brain structure, function, and total BDNF levels. As research advances, exercise is becoming increasingly acknowledged as an important technique for treating cognitive decline and neurodegenerative disorders.

Impact of exercise on cancer: mechanistic perspectives and new insights

This review critically evaluates the substantial role of exercise in enhancing cancer prevention, treatment, and patient quality of life. It conclusively demonstrates that regular physical activity not only reduces cancer risk but also significantly mitigates side effects of cancer therapies. The key findings include notable improvements in fatigue management, reduction of cachexia symptoms, and enhancement of cognitive functions. Importantly, the review elucidates the profound impact of exercise on tumor behavior, modulation of immune responses, and optimization of metabolic pathways, advocating for the integration of exercise into standard oncological care protocols. This refined abstract encourages further exploration and application of exercise as a pivotal element of cancer management.

Exercise potentially prevents colorectal cancer liver metastases by suppressing tumor epithelial cell stemness via RPS4X downregulation

Background

Colorectal cancer (CRC) is the third most prevalent tumor globally. The liver is the most common site for CRC metastasis, and the involvement of the liver is a common cause of death in patients with late-stage CRC. Consequently, mitigating CRC liver metastasis (CRLM) is key to improving CRC prognosis and increasing survival. Exercise has been shown to be an effective method of improving the prognosis of many tumor types. However, the ability of exercise to inhibit CRLM is yet to be thoroughly investigated.

Methods

The GSE157600 and GSE97084 datasets were used for analysis. A pan-cancer dataset which was uniformly normalized was downloaded and analyzed from the UCSC database: TCGA, TARGET, GTEx (PANCAN, n = 19,131, G = 60,499). Several advanced bioinformatics analyses were conducted, including single-cell sequencing analysis, correlation algorithm, and prognostic screen. CRC tumor microarray (TMA) as well as cell/animal experiments are used to further validate the results of the analysis.

Results

The greatest variability was found in epithelial cells from the tumor group. RPS4X was generally upregulated in all types of CRC, while exercise downregulated RPS4X expression. A lowered expression of RPS4X may prolong tumor survival and reduce CRC metastasis. RPS4X and tumor stemness marker-CD44 were highly positively correlated and knockdown of RPS4X expression reduced tumor stemness both in vitro and in vivo.

Conclusion

RPS4X upregulation may enhance CRC stemness and increase the odds of metastasis. Exercise may reduce CRC metastasis through the regulation of RPS4X.

Mechanisms of exercise in the treatment of lung cancer - a mini-review

Lung cancer constitutes a formidable menace to global health and well-being, as its incidence and mortality rate escalate at an alarming pace. In recent years, research has indicated that exercise has potential roles in both the prevention and treatment of lung cancer. However, the exact mechanism of the coordinating effect of exercise on lung cancer treatment is unclear, limiting the use of exercise in clinical practice. The purpose of this review is to explore the mechanisms through which exercise exerts its anticancer effects against lung cancer. This review will analyze the biological basis of exercise's anticancer effects on lung cancer, with a focus on aspects such as the tumor microenvironment, matrix regulation, apoptosis and angiogenesis. Finally, we will discuss future research directions and potential clinical applications.

Regular Voluntary Running is Associated with Increased Tumor Vascularization and Immune Cell Infiltration and Decreased Tumor Growth in Mice

Tumors present dysfunctional vasculature that limits blood perfusion and hinders immune cells delivery. We aimed to investigate if regular voluntary running promotes tumor vascular remodelling, improves intratumoral immune cells infiltration and inhibits tumor growth. Tumors were induced in C57BL/6 male mice (n=28) by subcutaneous inoculation in the dorsal region with a suspension of RM1 cells (1.5×10⁵ cells/500 µL PBS) and randomly allocated into two groups: sedentary (n=14) and voluntarily exercised on a wheel (n=14). Seven mice from each group were sacrificed 14 and 28 days after cells' inoculation to evaluate tumor weight, microvessel density, vessels' lumen regularity and the intratumoral quantity of NKG2D receptors, CD4⁺and CD8⁺T cells, by immunohistochemistry. The statistical inference was done through a two-way ANOVA. Exercised mice developed smaller tumors at 14 (0.17±0.1 g vs. 0.48±0.2 g, p<0.05) and 28 (0.92±0.7 g vs. 2.09±1.3 g, p<0.05) days, with higher microvessel density (21.20±3.2 vs. 15.86±4.0 vessels/field, p<0.05), more regular vessels' lumen (1.06±0.2 vs. 1.43±0.2, p<0.05), and higher CD8⁺T cells (464.95±48.0 vs. 364.70±49.4 cells/mm², p<0.01), after 28 days. NKG2D expression was higher in exercised mice at 14 (263.27±25.8 cells/mm², p<0.05) and 28 (295.06±56.2 cells/mm², p<0.001) days. Regular voluntary running modulates tumor vasculature, increases immune cells infiltration and attenuates tumor growth, in mice.

The effect of aerobic exercise on tumour blood delivery: a systematic review and meta-analysis

PURPOSE

Tumour blood vessels are structurally and functionally abnormal, resulting in areas of hypoxia and heterogeneous blood supply. Aerobic exercise may modulate tumour blood flow and normalise the tumour microenvironment to improve chemotherapy delivery. This systematic review and meta-analysis aimed to evaluate the effect of the aerobic exercise mode on tumour hypoxia, vascularisation and blood flow.

METHODS

Four online databases were searched. Preclinical and clinical randomised controlled trials examining the effects of aerobic exercise training on hypoxia, vascularisation or blood flow in solid tumours were included. The risk of bias was assessed and a meta-analysis performed.

RESULTS

Seventeen preclinical studies and one clinical study met criteria. Eleven studies assessed hypoxia, 15 studies assessed vascularisation and seven evaluated blood flow. There was large variability in measurement methods, tumour types and exercise program designs. The overall risk of bias was unclear in clinical and preclinical studies, owing to poor reporting. There was no significant effect of aerobic exercise on hypoxia (SMD = -0.17; 95% CI = -0.62, 0.28; I2 = 60%), vascularisation (SMD = 0.07; 95% CI = -0.40, 0.55; I2 = 71%) or blood flow (SMD = 0.01; 95% CI = -0.59, 0.61; I2 = 63%).

CONCLUSION

There is heterogeneity in methodology, resulting in evidence that is inconsistent and inconclusive for the effects of aerobic exercise on hypoxia, vascularisation and blood flow. Most evidence of aerobic exercise effects on tumour blood flow is in animal models, with very limited evidence in humans.

Validity of the peak velocity to detect physical training improvements in athymic mice

This study comprises two complementary experiments with athymic Balb/c (Nu/Nu) mice. In experiment 1, the aim was to verify the reproducibility of the peak velocity (V_Peak) determined from the incremental test. The second experiment aimed to assess the V_Peak sensitivity to prescribe and detect modulations of the physical training in athymic nude mice. Sixteen mice were submitted to two incremental treadmill tests separated by 48-h (Experiment 1). The test consisted of an initial warm-up of 5 minutes. Subsequently, animals initiated the tests at 8 m min⁻¹ with increments of 2 m min⁻¹ every 3 minutes. The V_Peak was determined as the highest velocity attained during the protocol. In experiment 2, these animals were randomly allocated to an exercise group (EG) or a control group (CG). The training protocol consisted of 30-min of treadmill running at 70% of the V_Peak five times a week for 4 weeks. High indexes of reproducibility were obtained for V_Peak (Test = 19.7 ± 3.6 m min⁻¹; Retest = 19.2 ± 3.4 m min⁻¹; p = 0.171; effect size = 0.142; r = 0.90). Animals from the EG had a significant increase of V_Peak (Before = 18.4 ± 2.7 m min⁻¹; After = 24.2 ± 6.0 m min⁻¹; p = 0.023). Conversely, a significant decrease was observed for the CG (Before = 21.1 ± 3.9 m min⁻¹; After = 15.9 ± 2.7 m min⁻¹; p = 0.038). The V_Peak is a valid parameter for exercise prescription in studies involving athymic nude mice.

Circadian rhythms and cancers: the intrinsic links and therapeutic potentials

The circadian rhythm is an evolutionarily conserved time-keeping system that comprises a wide variety of processes including sleep-wake cycles, eating-fasting cycles, and activity-rest cycles, coordinating the behavior and physiology of all organs for whole-body homeostasis. Acute disruption of circadian rhythm may lead to transient discomfort, whereas long-term irregular circadian rhythm will result in the dysfunction of the organism, therefore increasing the risks of numerous diseases especially cancers. Indeed, both epidemiological and experimental evidence has demonstrated the intrinsic link between dysregulated circadian rhythm and cancer. Accordingly, a rapidly increasing understanding of the molecular mechanisms of circadian rhythms is opening new options for cancer therapy, possibly by modulating the circadian clock. In this review, we first describe the general regulators of circadian rhythms and their functions on cancer. In addition, we provide insights into the mechanisms underlying how several types of disruption of the circadian rhythm (including sleep-wake, eating-fasting, and activity-rest) can drive cancer progression, which may expand our understanding of cancer development from the clock perspective. Moreover, we also summarize the potential applications of modulating circadian rhythms for cancer treatment, which may provide an optional therapeutic strategy for cancer patients.

Resistance and recurrence of malignancies after CAR-T cell therapy

The emergence of chimeric antigen receptor T (CAR-T) cell therapy has ushered a new era in cancer therapy, especially the treatment of hematological malignancies. However, resistance and recurrence still occur in some patients after CAR-T cell treatment. CAR-T cell inefficiency and tumor escape have emerged as the main challenges for the long-term disease control of B cell malignancies by this promising immunotherapy. In solid tumor treatment, CAR-T cells must also overcome many hurdles from the tumor or immune-suppressed tumor environment, which have become obstacles to the advancement of CAR-T therapy. Therefore, an understanding of the mechanisms underlying post-CAR treatment failure in patients is necessary. In this review, we characterize some mechanisms of resistance and recurrence after CAR-T cell therapy and correspondingly suggest reasonable treatment strategies.

The Effects of Physical Exercise on Tumor Vasculature: Systematic Review and Meta-analysis

A wealth of evidence supports an association between physical exercise, decreased tumor growth rate, and reduced risk of cancer mortality. In this context, the tumor vascular microenvironment may play a key role in modulating tumor biologic behavior. The present systematic review and meta-analysis aimed to summarize the evidence regarding the effects of physical exercise on tumor vasculature in pre-clinical studies. We performed a computerized research on the PubMed, Scopus, and EBSCO databases to identify pre-clinical studies that evaluated the effect of physical exercise on tumor vascular outcomes. Mean differences were calculated through a random effects model. The present systematic review included 13 studies involving 373 animals. From these, 11 studies evaluated chronic intratumoral vascular adaptations and 2 studies assessed the acute intratumoral vascular adaptations to physical exercise. The chronic intratumoral vascular adaptations resulted in higher tumor microvessel density in 4 studies, increased tumor perfusion in 2 studies, and reduced intratumoral hypoxia in 3 studies. Quantitatively, regular physical exercise induced an increased tumor vascularization of 2.13 [1.07, 3.20] (p<0.0001). The acute intratumoral vascular adaptations included increased vascular conductance and reduced vascular resistance, which improved tumor perfusion and attenuated intratumoral hypoxia. In pre-clinical studies, physical exercise seems to improve tumor vascularization.

Mechanistic Targets and Nutritionally Relevant Intervention Strategies to Break Obesity-Breast Cancer Links

The worldwide prevalence of overweight and obesity has tripled since 1975. In the United States, the percentage of adults who are obese exceeds 42.5%. Individuals with obesity often display multiple metabolic perturbations, such as insulin resistance and persistent inflammation, which can suppress the immune system. These alterations in homeostatic mechanisms underlie the clinical parameters of metabolic syndrome, an established risk factor for many cancers, including breast cancer. Within the growth-promoting, proinflammatory milieu of the obese state, crosstalk between adipocytes, immune cells and breast epithelial cells occurs via obesity-associated hormones, angiogenic factors, cytokines, and other mediators that can enhance breast cancer risk and/or progression. This review synthesizes evidence on the biological mechanisms underlying obesity-breast cancer links, with emphasis on emerging mechanism-based interventions in the context of nutrition, using modifiable elements of diet alone or paired with physical activity, to reduce the burden of obesity on breast cancer.