Vitamin D deficiency: a potential risk factor for cancer in obesity?

Advances in biomedical applications of vitamin D for VDR targeted management of obesity and cancer

BACKGROUND

1,25(OH)2D3 is a fat-soluble vitamin, involved in regulating Ca2+ homeostasis in the body. Its storage in adipose tissue depends on the fat content of the body. Obesity is the result of abnormal lipid deposition due to the prolonged positive energy balance and increases the risk of several cancer types. Furthermore, it has been associated with vitamin D deficiency and defined as a low 25(OH)2D3 blood level. In addition, 1,25(OH)2D3 plays vital roles in Ca2+-Pi and glucose metabolism in the adipocytes of obese individuals and regulates the expressions of adipogenesis-associated genes in mature adipocytes.

SCOPE AND APPROACH

The present contribution focused on the VDR mediated mechanisms interconnecting the obese condition and cancer proliferation due to 1,25(OH)2D3-deficiency in humans. This contribution also summarizes the identification and development of molecular targets for VDR-targeted drug discovery.

KEY FINDINGS AND CONCLUSIONS

Several studies have revealed that cancer development in a background of 1,25(OH)2D3 deficient obesity involves the VDR gene. Moreover, 1,25(OH)2D3 is also known to influence several cellular processes, including differentiation, proliferation, and adhesion. The multifaceted physiology of obesity has improved our understanding of the cancer therapeutic targets. However, currently available anti-cancer drugs are notorious for their side effects, which have raised safety issues. Thus, there is interest in developing 1,25(OH)2D3-based therapies without any side effects.

Risk of cancer in patients with bile acid diarrhoea: a Danish nationwide matched cohort study

OBJECTIVE

Bile acid diarrhoea is a common cause of chronic diarrhoea. Increased levels of potentially carcinogenic bile acids in faeces, theoretically, may increase the risk of colorectal cancer in particular, but the long-term disease course is unknown. We aimed to investigate the overall and site-specific cancer risk in bile acid diarrhoea.

DESIGN

Adult patients with bile acid diarrhoea were identified using nationwide Danish registries from 2003 to 2020 by a diagnostic gold-standard 75-selenium tauroselcholic acid procedure followed within 6 months by sequestrant prescription. The risk of overall and site-specific cancers in cases with bile acid diarrhoea was compared with sex, age and comorbidity-adjusted matched controls. A competing risk model estimated cumulative incidence functions and cause-specific HRs.

RESULTS

We identified 2260 patients with bile acid diarrhoea with a mean follow-up of 5.5 years (SD 4.2). The overall cancer risk was increased by an HR of 1.32 (95% CI 1.12 to 1.54). The risk of site-specific cancer was increased in 3 of 10 cancer groups: haematological, HR 2.41 (1.36 to 4.02); skin, HR 1.33 (1.01 to 1.71); and male genital cancers, HR 1.85 (1.11 to 2.92). No increased risk of colorectal cancer was detected in patients with bile acid diarrhoea, HR 0.73 (0.34 to 1.63).

CONCLUSIONS

Bile acid diarrhoea was associated with an increased overall risk of cancer, especially haematological cancers, but the risk of colorectal cancer was not increased. The lack of a diagnostic code for bile acid diarrhoea and potential residual confounding are limitations, and the findings should be replicated in other cohorts.

Accurate Clinical Detection of Vitamin D by Mass Spectrometry: A Review

Vitamin D deficiency is thought to be associated with a wide range of diseases, including diabetes, cancer, depression, neurodegenerative diseases, and cardiovascular and cerebrovascular diseases. This vitamin D deficiency is a global epidemic affecting both developing and developed countries and therefore qualitative and quantitative analysis of vitamin D in a clinical context is essential. Mass spectrometry has played an increasingly important role in the clinical analysis of vitamin D because of its accuracy, sensitivity, specificity, and the ability to detect multiple substances at the same time. Despite their many advantages, mass spectrometry-based methods are not without analytical challenges. Front-end and back-end challenges such as protein precipitation, analyte extraction, derivatization, mass spectrometer functionality, must be carefully considered to provide accurate and robust analysis of vitamin D through a well-designed approach with continuous control by internal and external quality control. Therefore, the aim of this review is to provide a comprehensive overview of the development of mass spectrometry methods for vitamin D accurate analysis, including emphasis on status markers, deleterious effects of biological matrices, derivatization reactions, effects of ionization sources, contribution of epimers, standardization of assays between laboratories.

The Magic Triangle in Oral Potentially Malignant Disorders: Vitamin D, Vitamin D Receptor, and Malignancy

OPMDs (oral potentially malignant disorders) are a group of disorders affecting the oral mucosa that are characterized by aberrant cell proliferation and a higher risk of malignant transformation. Vitamin D (VitD) and its receptor (VDR) have been extensively studied for their potential contributions to the prevention and therapeutic management of various diseases and neoplastic conditions, including oral cancer. Observational studies suggest correlations between VitD deficiency and higher cancer risk, worse prognosis, and increased mortality rates. Interestingly, emerging data also suggest a link between VitD insufficiency and the onset or progression of OPMDs. Understanding the role of the VitD-VDR axis not only in established oral tumors but also in OPMDs might thus enable early detection and prevention of malignant transformation. With this article, we want to provide an overview of current knowledge about OPMDs and VitD and investigate their potential association and ramifications for clinical management of OPMDs.

Potential tactics with vitamin D and certain phytochemicals for enhancing the effectiveness of immune-checkpoint blockade therapies

Immunotherapy strategies targeting immune checkpoint molecules such as programmed cell death-1 (PD-1) and cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) are revolutionizing oncology. However, its effectiveness is limited in part due to the loss of effector cytotoxic T lymphocytes. Interestingly, supplementation of vitamin D could abolish the repressive effect of programmed cell death-ligand 1 (PD-L1) on CD8⁺ T cells, which might prevent the lymphocytopenia. In addition, vitamin D signaling could contribute to the differentiation of T-regulatory (Treg) cells associated with the expression of Treg markers such as forkhead box P3 (FOXP3) and CTLA-4. Furthermore, vitamin D may be associated with the stimulation of innate immunity. Peroxisome proliferator-activated receptor (PPAR) and estrogen receptor (ESR) signaling, and even the signaling from phosphoinositide-3 kinase (PI3K)/AKT pathway could have inhibitory roles in carcinogenesis possibly via the modulation of immune checkpoint molecules. In some cases, certain small molecules including vitamin D could be a novel therapeutic modality with a promising potential for the better performance of immune checkpoint blockade cancer therapies.

The effects of vitamin D on all-cause mortality in different diseases: an evidence-map and umbrella review of 116 randomized controlled trials

Purpose

To conduct a solid evidence by synthesizing meta-analyses and updated RCTs about the effects of vitamin D on all-cause mortality in different health conditions.

Methods

Data sources: Pubmed, Embase, Web of Science, the Cochrane Library, Google Scholar from inception until 25th April, 2022. Study selection: English-language, meta-analyses and updated RCTs assessing the relationships between vitamin D and all-cause mortality. Data synthesis: Information of study characteristics, mortality, supplementation were extracted, estimating with fixed-effects model. A Measurement Tool to Assess Systematic Reviews, Grading of Recommendations Assessment, Development and Evaluation, and funnel plot was used to assess risk of bias. Main outcomes: All-cause mortality, cancer mortality, cardiovascular disease mortality.

Results

In total of 27 meta-analyses and 19 updated RCTs were selected, with a total of 116 RCTs and 149, 865 participants. Evidence confirms that vitamin D reduces respiratory cancer mortality (RR, 0.56 [95%CI, 0.33 to 0.96]). All-cause mortality is decreased in patients with COVID-19 (RR, 0.54[95%CI, 0.33 to 0.88]) and liver diseases (RR, 0.64 [95%CI, 0.50 to 0.81]), especially in liver cirrhosis (RR, 0.63 [95%CI, 0.50 to 0.81]). As for other health conditions, such as the general health, chronic kidney disease, critical illness, cardiovascular diseases, musculoskeletal diseases, sepsis, type 2 diabetes, no significant association was found between vitamin D and all-cause mortality.

Conclusions

Vitamin D may reduce respiratory cancer mortality in respiratory cancer patients and all-cause mortality in COVID-19 and liver disorders' patients. No benefits showed in all-cause mortality after vitamin D intervention among other health conditions. The hypothesis of reduced mortality with vitamin D still requires exploration.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=252921, identifier: CRD42021252921.

Exploiting Vitamin D Receptor and Its Ligands to Target Squamous Cell Carcinomas of the Head and Neck

Vitamin D (VitD) and its receptor (VDR) have been intensively investigated in many cancers. As knowledge for head and neck cancer (HNC) is limited, we investigated the (pre)clinical and therapeutic relevance of the VDR/VitD-axis. We found that VDR was differentially expressed in HNC tumors, correlating to the patients' clinical parameters. Poorly differentiated tumors showed high VDR and Ki67 expression, whereas the VDR and Ki67 levels decreased from moderate to well-differentiated tumors. The VitD serum levels were lowest in patients with poorly differentiated cancers (4.1 ± 0.5 ng/mL), increasing from moderate (7.3 ± 4.3 ng/mL) to well-differentiated (13.2 ± 3.4 ng/mL) tumors. Notably, females showed higher VitD insufficiency compared to males, correlating with poor differentiation of the tumor. To mechanistically uncover VDR/VitD's pathophysiological relevance, we demonstrated that VitD induced VDR nuclear-translocation (VitD < 100 nM) in HNC cells. RNA sequencing and heat map analysis showed that various nuclear receptors were differentially expressed in cisplatin-resistant versus sensitive HNC cells including VDR and the VDR interaction partner retinoic acid receptor (RXR). However, RXR expression was not significantly correlated with the clinical parameters, and cotreatment with its ligand, retinoic acid, did not enhance the killing by cisplatin. Moreover, the Chou-Talalay algorithm uncovered that VitD/cisplatin combinations synergistically killed tumor cells (VitD < 100 nM) and also inhibited the PI3K/Akt/mTOR pathway. Importantly, these findings were confirmed in 3D-tumor-spheroid models mimicking the patients' tumor microarchitecture. Here, VitD already affected the 3D-tumor-spheroid formation, which was not seen in the 2D-cultures. We conclude that novel VDR/VitD-targeted drug combinations and nuclear receptors should also be intensely explored for HNC. Gender-specific VDR/VitD-effects may be correlated to socioeconomic differences and need to be considered during VitD (supplementation)-therapies.

Gluten-Free Diet and Metabolic Syndrome: Could Be a Not Benevolent Encounter?

Celiac disease is a rising disorder and is becoming frequently diagnosed in recent years. To date, the only available treatment is the gluten-free diet (GFD). The role of gluten on components of metabolic syndrome and on related inflammatory response is still unclear due to controversial results. In recent years, scientific focus on this topic has been growing up, in particular regarding the role of the GFD on glycometabolic parameters and diabetes. In addition, studies on the remaining components showed discordant results, which was likely due to heterogeneous and large celiac disease populations and to the lack of prospective studies. Furthermore, knowledge about the role of the GFD on inflammatory cytokines and the relationship among vitamin D and celiac disease, metabolic syndrome (MS) and GFD is needed. In this narrative review, we provided evidence regarding the role of the GFD on glycometabolic parameters, cholesterol, triglycerides, waist circumference, blood pressure and inflammatory cascade, also evaluating the role of vitamin D, trying to summarize whether this nutritional pattern may be a value-added for subjects with dysmetabolic conditions. Finally, due to the limited findings and very low-certainty evidence, predominantly based on observational studies, the real effects of a GFD on different components of MS, however, are unclear; nevertheless, an improvement in HDL levels has been reported, although data on glycemic levels are discordant.

Micronutrient deficiencies and anaemia associated with body mass index in Australian adults: a cross-sectional study

AIM

To estimate the prevalence of micronutrient deficiencies and anaemia, and their association with body mass index (BMI) categories among Australian adults.

METHOD

We analysed data from the 2011-2013 Australian Health Survey from 3539 participants aged 18 years and over (without known pregnancy) with measured weight and height, and nutrient biomarkers. To address complex sampling, survey weights were used when estimating the prevalence of micronutrient deficiencies (vitamin B₁₂ deficiency; serum vitamin B₁₂<145 pmol/L; iron deficiency; ferritin<30 µg/L and vitamin D deficiency; 25-hydroxyvitamin D<50 nmol/L) and anaemia (haemoglobin <120 g/L for females and <130 g/L for males) and when assessing associations with logistic regression models with adjusted ORs (AORs) for BMI categories: healthy weight (BMI 18.5 to <25.0 kg/m²), reference; overweight (BMI 25.0 to <30.0 kg/m²), obesity class I (BMI 30.0 to <35.0 kg/m²), obesity class II/III (BMI 35.0 kg/m² or more).

RESULT

The prevalence of vitamin B₁₂ deficiency (range 0.9%─2.8%) and anaemia (range 3.9%─6.7%) were variable across BMI groups. The prevalence of iron deficiency in the obesity class I group was 12.0 percentage points lower than healthy weight group with an AOR of 0.50 (95% CI 0.30 to 0.83). The prevalence of vitamin D deficiency in the obesity class II/III group was 7.9 percentage points higher than the healthy weight group with an AOR of 1.62 (95% CI 1.01 to 2.60). Vitamin B₁₂ deficiency and anaemia were not consistently associated with BMI groups.

CONCLUSION

We found a consistent association between severe obesity and vitamin D deficiency in Australian adults. We also found obesity class I was negatively associated with iron deficiency, whereas there was no consistent association between BMI groups and vitamin B₁₂ deficiency and anaemia. Public health strategies are needed to prevent vitamin D deficiency in this high-risk population.

Vitamin D Levels in Newly Diagnosed Breast Cancer Patients according to Tumor Sub-Types

Vitamin D is an important regulator of bone health. In addition, as a ligand for a nuclear receptor expressed in breast cancer cells, vitamin D exerts neoplasia modulating effects in breast cancer. However, despite extensive investigations, associations of vitamin D levels with breast cancer patient characteristics and disease sub-types are conflicting. A retrospective review of medical records of consecutive breast cancer patients treated and followed in a single cancer center was undertaken. All patients with 25-hydroxyvitamin D (25-OHD, the circulating form of vitamin D) measurements available within 3 months of their diagnosis and before the start of any systemic treatment were included. Characteristics of patients and tumors with sufficient levels of 25-OHD were compared with those of patients with 25-OHD insufficiency. Two hundred ninety-two patients were included in the study. Almost two-thirds of the patients were 25-OHD insufficient, defined as having 25-OHD levels below 75 nmol/L. Compared with the group of patients who were 25-OHD sufficient, patients with 25-OHD insufficiency were younger and more often obese. Tumors of patients with 25-OHD insufficiency were more often ductal, of higher grade, and ER negative. 25-OHD insufficiency is prevalent in breast cancer patients and even more prevalent in younger and obese patients. 25-OHD insufficiency is associated with cancers that have aggressive characteristics, including higher grade and ER negativity.

Vitamin D Reduces Thyroid Cancer Cells Migration Independently From the Modulation of CCL2 and CXCL8 Chemokines Secretion

BACKGROUND

Vitamin D3 is largely involved in the regulation of calcium homeostasis. More recently, it was demonstrated that vitamin D exerts several beneficial effects against cancer progression through several mechanisms, including the reduction of cancer cells proliferation and migration. CXCL8 and CCL2 are two chemokines secreted by thyroid tumor cells. In the thyroid tumor microenvironment, these chemokines exert several pro-tumorigenic effects including the one to increase the metastatic potential. The aim of the present study was to investigate if vitamin D could modulate both thyroid cancer cell migration and their ability to secrete CCL2 and CXCL8.

METHODS

TPC-1 (RET/PTC rearranged) and 8505C (BRAFV600e mutated) thyroid cancer cell lines were treated with increasing concentrations of 1,25-OH-vitamin D3 (0-1,000 nM). Cell viability was assessed by WST-1 assay, cell migration was evaluated by transwell-migration chamber system, and CCL2 and CXCL8 levels were measured in the cell culture supernatants by ELISA.

RESULTS

Vitamin D did not affect cell viability but reduced, in a dose-dependent and significant manner, thyroid cancer cell migration (ANOVAs p < 0.05 for both TPC-1 and 8505C). Vitamin D differently modulated the secretion of CCL2 and CXCL8, by significantly inhibiting the secretion of CCL2 in both thyroid cancer cell lines and inhibiting the secretion of CXCL8 only in TPC-1 (ANOVAs p < 0.05).

CONCLUSIONS

Vitamin D treatment of thyroid cancer cell lines reduces cell migration independently from the inhibition of the secretion of pro-tumorigenic chemokines. Future studies specifically designed at clarifying the pathways involved in the different inhibitory effects of vitamin D on CCL2 and CXCL8 in thyroid cancer cells appear worthwhile.