Association between serum 25-hydroxyvitamin D and global DNA methylation in visceral adipose tissue from colorectal cancer patients

Expression profiles and gene set enrichment analysis of the transcriptomes from the cancer tissue, white adipose tissue and paracancer tissue with colorectal cancer

Background

Colorectal cancer (CRC) is one of the most common cancers worldwide and is related to diet and obesity. Currently, crosstalk between lipid metabolism and CRC has been reported; however, the specific mechanism is not yet understood. In this study, we screened differentially expressed long non-coding RNAs (lncRNAs) and mRNAs from primary cancer, paracancer, and white adipose tissue of CRC patients. We screened and analyzed the genes differentially expressed between primary and paracancer tissue and between paracancer and white adipose tissue but not between primary and white adipose tissue. According to the results of the biological analysis, we speculated a lncRNA (MIR503HG) that may be involved in the crosstalk between CRC and lipid metabolism through exosome delivery.

Methods

We screened differentially expressed long non-coding RNAs (lncRNAs) and mRNAs from primary cancer, paracancer, and white adipose tissue of CRC patients. We screened and analyzed the genes differentially expressed between primary and paracancer tissue and between paracancer and white adipose tissue but not between primary and white adipose tissue.

Results

We speculated a lncRNA (MIR503HG) that may be involved in the crosstalk between CRC and lipid metabolism through exosome delivery.

Conclusions

In this study, the findings raise the possibility of crosstalk between lipid metabolism and CRC through the exosomal delivery of lncRNAs.

Epigenetic modifications in obesity-associated diseases

The global prevalence of obesity has reached epidemic levels, significantly elevating the susceptibility to various cardiometabolic conditions and certain types of cancer. In addition to causing metabolic abnormalities such as insulin resistance (IR), elevated blood glucose and lipids, and ectopic fat deposition, obesity can also damage pancreatic islet cells, endothelial cells, and cardiomyocytes through chronic inflammation, and even promote the development of a microenvironment conducive to cancer initiation. Improper dietary habits and lack of physical exercise are important behavioral factors that increase the risk of obesity, which can affect gene expression through epigenetic modifications. Epigenetic alterations can occur in early stage of obesity, some of which are reversible, while others persist over time and lead to obesity-related complications. Therefore, the dynamic adjustability of epigenetic modifications can be leveraged to reverse the development of obesity-associated diseases through behavioral interventions, drugs, and bariatric surgery. This review provides a comprehensive summary of the impact of epigenetic regulation on the initiation and development of obesity-associated cancers, type 2 diabetes, and cardiovascular diseases, establishing a theoretical basis for prevention, diagnosis, and treatment of these conditions.

The role of vitamin D on redox regulation and cellular senescence

Vitamin D is considered an essential micronutrient for human health that is metabolized into a multifunctional secosteroid hormone. We can synthesize it in the skin through ultraviolet B (UVB) rays or acquire it from the diet. Its deficiency is a major global health problem that affects all ages and ethnic groups. Furthermore, dysregulation of vitamin D homeostasis has been associated with premature aging, driven by various cellular processes, including oxidative stress and cellular senescence. Various studies have shown that vitamin D can attenuate oxidative stress and delay cellular senescence, mainly by inducing the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and Klotho and improving mitochondrial homeostasis, proposing this vitamin as an excellent candidate for delaying aging. However, the mechanisms around these processes are not yet fully explored. Therefore, in this review, the effects of vitamin D on redox regulation and cellular senescence are discussed to propose new lines of research and clinical applications of vitamin D in the context of age-related diseases.

Epigenomic effects of vitamin D in colorectal cancer

Vitamin D regulates a plethora of physiological processes in the human body and has been proposed to exert several anticancer effects. Epigenetics plays an important role in regulating vitamin D actions. In this review, we highlight the recent advances in the understanding of different epigenetic factors such as lncRNAs, miRNAs, methylation and acetylation influenced by vitamin D and its downstream targets in colorectal cancer to find more potential therapeutic targets. We discuss how vitamin D exerts anticancer properties through interactions between the vitamin D receptor and genes (e.g., SLC30A10), the microenvironment, microbiota and other factors in colorectal cancer. Developing therapeutic approaches targeting the vitamin D signaling system will be aided by a better knowledge of the epigenetic impact of vitamin D.

Deregulation of CircANXA2, Circ0075001, and CircFBXW7 Gene Expressions and Their Predictive Value in Egyptian Acute Myeloid Leukemia Patients

Background

Aim of the Work

Methods

Results

Conclusion

DNA methylome in visceral adipose tissue can discriminate patients with and without colorectal cancer

Adipose tissue dysfunction, particularly the visceral (VAT) compartment, has been proposed to play a relevant role in colorectal cancer (CRC) development and progression. Epigenetic mechanisms could be involved in this association. The current study aimed to evaluate if specific epigenetic marks in VAT are associated with colorectal cancer (CRC) to identify epigenetic hallmarks of adipose tissue-related CRC. Epigenome-wide DNA methylation was evaluated in VAT from 25 healthy participants and 29 CRC patients, using the Infinium HumanMethylation450K BeadChip. The epigenome-wide methylation analysis identified 170,184 sites able to perfectly separate the CRC and healthy samples. The differentially methylated CpG sites (DMCpGs) showed a global trend for increased methylated levels in CRC with respect to healthy group. Most of the genes encoded by the DMCpGs belonged to metabolic pathways and cell cycle, insulin resistance, and adipocytokine signalling, as well as tumoural transformation processes. In gene-specific analyses, involved genes biologically relevant for the development of CRC include PTPRN2, MAD1L1, TNXB, DIP2C, INPP5A, HDCA4, PRDM16, RPTOR, ATP11A, TBCD, PABPC3, and IER2. The methylation level of some of them showed a discriminatory capacity for detecting CRC higher than 90%, showing IER2 to have the highest capacity. This study reveals that a specific methylation pattern of VAT is associated with CRC. Some of the epigenetic marks identified could provide useful tools for the prediction and personalized treatment of CRC connected to excess adiposity.

An Epigenetic Signature is Associated with Serum 25-Hydroxyvitamin D in Colorectal Cancer Tumors

INTRODUCTION

Vitamin D has been widely associated with colorectal cancer (CRC) through different insights. This study aims to explore the association between serum 25-hydroxyvitamin D (25(OH)D) and the global DNA methylation in tumor from CRC patients.

METHODS AND RESULTS

A genome-wide DNA methylation analysis is conducted in 20 CRC patients under categorical (10 patients have 25(OH)D <30 ng mL^-1 ; 10 patients with 25(OH)D ≥30 ng mL^-1 ) and continuous models of 25(OH)D. A total of 95 differentially methylated CpGs (DMCpGs) are detected under the categorical model (false discovery rate (FDR) < 0.05), while 16 DMCpGs are found under the continuous model. Regional analysis showed eight vitamin D-associated differentially methylated regions (DMR). Between them, a DMR is the most significant at cAMP-Dependent Protein Kinase Inhibitor Alpha (PKIA) locus. Furthermore, seven genes, including PKIA gene, have more or equal than two significant DMCpGs. The protein networking analysis found pathways implicated in cell adhesion and extracellular matrix, as well as signaling transduction.

CONCLUSIONS

This study identifies novel epigenetic loci associated with serum 25(OH)D status. Interestingly, also, a positive association between vitamin D and DNA methylation in the CRC context is found, suggesting a role in CRC. Further studies are warranted to clarify and replicate these results.

Newly-identified Pathways Relating Vitamin D to Carcinogenesis: A Review

BACKGROUND

The epidemiological relationship between vitamin D levels and cancer has been thoroughly investigated. Published data from large studies appear to corroborate a significant relationship between higher serum vitamin D concentrations and improved survival. Mechanistic reviews on commonly-studied cancers - including breast cancer, colon cancer and melanoma - focus predominantly on data from older studies. In outlining avenues for future research, we believe there is utility in summarizing novel findings introduced to the literature.

MATERIALS AND METHODS

In this narrative review, we used MEDLINE, PUBMED and Cochrane databases to identify mechanistic studies published from January 1, 2015 onwards exploring this topic.

RESULTS

Twenty-five mechanistic studies were included in this review. It was found that vitamin D plays a critical role in both direct (i.e. tumor gene expression, proliferation, invasiveness, sensitivity to chemotherapy etc.) and indirect (i.e. effects on the tumor microenvironment and immunomodulation) tumor suppression mechanisms.

CONCLUSION

These newly-identified pathways warrant further research, with the hopes that we may understand how and when vitamin D supplementation can be integrated into precision medicine therapeutics for cancers of the breast, colon and skin. Cancer care providers should consider recommendations to screen for vitamin D deficiency in this population.

Potential effects of nutrition-based weight loss therapies in reversing obesity-related breast cancer epigenetic marks

Obesity is a modifiable risk factor of breast cancer and epigenetic marks were proposed as a relevant mechanistic link. These mechanisms can be remodelled by modifying lifestyle factors and this fact could be useful in the treatment of obesity-related breast cancer. This review aimed to reveal the current evidence on the effects of differences in body composition and lifestyle factors on the risk, treatment, and survival of breast cancer with a focus on the effects of weight loss therapies based on different nutrients, bioactive compounds, and Mediterranean and ketogenic diets to counteract obesity-related breast cancer epigenetic marks. This review was framed on the most relevant and recently published articles and abstracts selected in PubMed using key words related to epigenetics, lifestyle, dietary habits, nutrients, bioactive compounds, ketone bodies, and weight loss treatments in obesity and breast cancer. Several studies have demonstrated that lifestyle interventions, including dietary modifications towards a healthy diet pattern, are effective therapies to prevent the onset of breast cancer and to improve the survival after treatment. These therapies reduce the main factors associated with obesity that are links between adiposity and cancer, including oxidative stress, inflammation and epigenetic mechanisms. However, although sufficient evidence exists regarding the effects of nutrients, dietary patterns, and weight loss therapies to prevent breast cancer or to improve survival, the effects of these strategies on the oncological treatment response were less studied. This review summarises the current scientific evidence regarding these nutritional strategies as adjuvant therapies in the management of obesity-related breast cancer by remodelling epigenetic marks related to carcinogenesis.

Vitamin D and its Effects on DNA Methylation in Development, Aging, and Disease

DNA methylation is increasingly being recognized as a mechanism through which environmental exposures confer disease risk. Several studies have examined the association between vitamin D and changes in DNA methylation in areas as diverse as human and animal development, genomic stability, chronic disease risk, and malignancy. In many cases, they have demonstrated clear associations between vitamin D and DNA methylation in candidate disease pathways. Despite this, a clear understanding of the mechanisms by which these factors interact is unclear. This paper reviews the current understanding of the effects of vitamin D on DNA methylation. In light of current knowledge in the field, the potential mechanisms mediating vitamin D effects on DNA methylation are discussed, as are the limiting factors and future avenues for research into this exciting area.

Vitamin D in obesity and obesity-related diseases: an overview

Hypovitaminosis D and obesity represent two pandemic conditions sometimes associated with each other. Although it is known that there is a close relationship between these two health problems, the underlying pathophysiological mechanism has not yet been fully clarified. In fact, on the one hand, obesity per se seems to involve low circulating levels of vitamin D due to low sun exposure, physical activity, and intake of foods rich in vitamin D, volumetric dilution and sequestration in the adipose tissue. Conversely, since preadipocytes and adipocytes express the receptors and are involved in the metabolism of vitamin D it would seem that low levels of this vitamin may be involved in adipogenesis and therefore in the development of obesity. This connection is extremely important when considering obesity-related diseases. In fact, low vitamin D levels and severe obesity are significantly associated with some cardio-metabolic risk factors, including high Body Mass Index, waist circumference, blood pressure, impaired lipid and glycemic profile and insulin resistance, as they would seem associated with worse cardiovascular outcomes and higher cancer incidence and mortality. Therefore, the purpose of this review was to examine the recent evidence linking low vitamin D status, obesity and obesity-related diseases, highlighting the scientific achievements and the gaps to be filled with further investigations.

Genome-Protecting Compounds as Potential Geroprotectors

Throughout life, organisms are exposed to various exogenous and endogenous factors that cause DNA damages and somatic mutations provoking genomic instability. At a young age, compensatory mechanisms of genome protection are activated to prevent phenotypic and functional changes. However, the increasing stress and age-related deterioration in the functioning of these mechanisms result in damage accumulation, overcoming the functional threshold. This leads to aging and the development of age-related diseases. There are several ways to counteract these changes: 1) prevention of DNA damage through stimulation of antioxidant and detoxification systems, as well as transition metal chelation; 2) regulation of DNA methylation, chromatin structure, non-coding RNA activity and prevention of nuclear architecture alterations; 3) improving DNA damage response and repair; 4) selective removal of damaged non-functional and senescent cells. In the article, we have reviewed data about the effects of various trace elements, vitamins, polyphenols, terpenes, and other phytochemicals, as well as a number of synthetic pharmacological substances in these ways. Most of the compounds demonstrate the geroprotective potential and increase the lifespan in model organisms. However, their genome-protecting effects are non-selective and often are conditioned by hormesis. Consequently, the development of selective drugs targeting genome protection is an advanced direction.

Vitamin D in physiological and pathological aging: Lesson from centenarians

Vitamin D is a secosteroid hormone that exerts a pleiotropic action on a wide spectrum of tissues, apparatuses and systems. Thus, vitamin D has assumed an increasingly dominant role as a key determinant of biological mechanisms and specific clinical conditions. Older people frequently present vitamin D deficiency, a status potentially influencing several mechanisms responsible for different age-related diseases. Centenarians symbolize the ideal model for investigating the peculiar traits of longevity, as they have reached an age close to the estimated limit of the human lifespan. Interestingly, despite the profound heterogeneity of centenarians in terms of health status, all these people share the same condition of severe vitamin D deficiency, suggesting that they may have implemented a number of adaptive strategies to cope with the age-related physiological derangement of vitamin D metabolism. The lesson deriving from centenarians' experience suggests that: i) severe vitamin D deficiency does not preclude the possibility of reaching extreme longevity, ii) strategies to prevent hypovitaminosis D may be useful to slow down the processes of "fragilization" occurring in aged people, iii) beneficial effects of vitamin D supplementation need to be confirmed regarding longevity.

DNA Methylation Status in Cancer Disease: Modulations by Plant-Derived Natural Compounds and Dietary Interventions

The modulation of the activity of DNA methyltransferases (DNMTs) represents a crucial epigenetic mechanism affecting gene expressions or DNA repair mechanisms in the cells. Aberrant modifications in the function of DNMTs are a fundamental event and part of the pathogenesis of human cancer. Phytochemicals, which are biosynthesized in plants in the form of secondary metabolites, represent an important source of biomolecules with pleiotropic effects and thus provide a wide range of possible clinical applications. It is well documented that phytochemicals demonstrate significant anticancer properties, and in this regard, rapid development within preclinical research is encouraging. Phytochemicals affect several epigenetic molecular mechanisms, including DNA methylation patterns such as the hypermethylation of tumor-suppressor genes and the global hypomethylation of oncogenes, that are specific cellular signs of cancer development and progression. This review will focus on the latest achievements in using plant-derived compounds and plant-based diets targeting epigenetic regulators and modulators of gene transcription in preclinical and clinical research in order to generate novel anticancer drugs as sensitizers for conventional therapy or compounds suitable for the chemoprevention clinical setting in at-risk individuals. In conclusion, indisputable anticancer activities of dietary phytochemicals linked with proper regulation of DNA methylation status have been described. However, precisely designed and well-controlled clinical studies are needed to confirm their beneficial epigenetic effects after long-term consumption in humans.

Novel SFRP2 DNA Methylation Profile Following Neoadjuvant Therapy in Colorectal Cancer Patients with Different Grades of BMI

The relationship between body weight and different cancers is now well-recognized and among such cancers, colorectal cancer (CRC) is reported most frequently. Our group recently published findings, through an epigenome-wide association study, suggesting that body mass index (BMI) could act as a relevant risk factor in the CRC. In addition, aberrant SFRP2 methylation is one of the major mechanisms for Wnt signaling activation in CRC. Conversely, neoadjuvant chemo-radiotherapy appears to alter the rectal cancer epigenome. This study was aimed to evaluate the effect of obesity, measured by BMI, on the methylation of SFRP2 in tumor samples of patients with CRC. Non-treated CRC patients and CRC patients treated with pre-operative neoadjuvant therapy from 2011 to 2013 were included and classified by BMI < 25.0 kg/m² and BMI > 25.0 kg/m². SFRP2 DNA methylation in tumor samples was measured by pyrosequencing. Our findings suggest a possible interaction between SFRP2 methylation levels and BMI in CRC tumor samples. The correlation of SFRP2 hypomethylation with an elevated BMI was stronger within the non-treated CRC patient group than within the treated CRC patient group. We have successfully demonstrated that the beneficial association of tumor SFRP2 hypomethylation is dependent on patient BMI in non-treated CRC, suggesting a possible tumor suppressor role for SFRP2 in overweight and obese patients. Additional studies of clinical pathologies would be necessary to strengthen these preliminary results.

Epigenetic Influences in the Obesity/Colorectal Cancer Axis: A Novel Theragnostic Avenue

The World Health Organization (WHO) considers that obesity has reached proportions of pandemic. Experts also insist on the importance of considering obesity as a chronic disease and one of the main contributors to the worldwide burden of other nontransmissible chronic diseases, which have a great impact on health, lifestyle, and economic cost. One of the most current challenges of biomedical science faces is to understand the origin of the chronic nontransmissible diseases, such as obesity and cancer. There is a large evidence, both in epidemiological studies in humans and in animal models, of the association between obesity and an increased risk of cancer incidence. In the last years, the initial discovery of epigenetic mechanisms represents the most relevant finding to explain how the genome interacts with environmental factors and the ripple effects on disease pathogeneses. Since then, all epigenetic process has been investigated by the scientific communities for nearly two decades to determine which components are involved in this process. DNA/RNA methylation and miRNA are classified as two of the most important representative classes of such epigenetic mechanisms and dysregulated activity of such mechanism can certainly contribute to disease pathogenesis and/or progression especially in tumors. This review article serves to highlight the impact of DNA/RNA methylation and miRNA-based epigenetic mechanism activities in the interplay between obesity and the development and clinical significance of colorectal cancer.