Exploring vitamin D metabolism and function in cancer

The Combination of the CDK4/6 Inhibitor, Palbociclib, With the Vitamin D3 Analog, Inecalcitol, Has Potent In Vitro and In Vivo Anticancer Effects in Hormone-Sensitive Breast Cancer, But Has a More Limited Effect in Triple-Negative Breast Cancer

Active vitamin D₃, 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃], and its synthetically derived analogs possess potent anticancer properties. In breast cancer (BC) cells, 1,25(OH)₂D₃ blocks cell proliferation and induces apoptosis through different cell-type specific mechanisms. In this study, we evaluated if the combination of the potent vitamin D₃ analog, inecalcitol, with a selective CDK4/6 inhibitor, palbociclib, enhanced the antiproliferative effects of both single compounds in hormone-sensitive (ER⁺) BC, for which palbociclib treatment is already approved, but also in triple-negative BC (TNBC). Inecalcitol and palbociclib combination treatment decreased cell proliferation in both ER⁺ (T47D-MCF7) and TNBC (BT20-HCC1143-Hs578T) cells, with a more pronounced antiproliferative effect in the former. In ER⁺ BC cells, the combination therapy downregulated cell cycle regulatory proteins (p)-Rb and (p)-CDK2 and blocked G1-S phase transition of the cell cycle. Combination treatment upregulated p-mTOR and p-4E-BP1 protein expression in MCF7 cells, whereas it suppressed expression of these proteins in BT20 cells. Cell survival was decreased after inecalcitol treatment either alone or combined in MCF7 cells. Interestingly, the combination therapy upregulated mitochondrial ROS and mitotracker staining in both cell lines. Furthermore, in vivo validation in a MCF7 cell line-derived xenograft mouse model decreased tumor growth and cell cycle progression after combination therapy, but not in a TNBC BT20 cell line-derived xenograft model. In conclusion, we show that addition of a potent vitamin D₃ analog to selective CDK4/6 inhibitor treatment results in increased antiproliferative effects in ER⁺ BC both in vitro and in vivo.

The Vitamin D Role in Preventing Primary Headache in Adult and Pediatric Population

Headache is among the main neurological disorders with a great impact on both adults and children. The diagnosis of primary headache and proper management is often delayed with a great impact on work productivity and overall quality of life. Chronic headache often requires prophylactic therapy to reduce the frequency and severity of the attacks and the use of abortive medications. Besides the use of several classes of drugs, another treatment modality is the use of Nutraceuticals. Some studies have suggested a possible role of vitamin D in headache prophylaxis. Indeed, vitamin D is involved in several pathways of brain development, neuroprotection and neurotransmission. Moreover, there is data suggesting a close relationship between primary headache and vitamin D deficiency, both in children and in adults. To date, a few studies have evaluated the effect of vitamin D on headaches. The aim of this review is to summarize the data collected on headache prophylaxis with vitamin D comparing the effects of vitamin D in pediatric and adult populations.

Vitamin D-Mediated Anti-cancer Activity Involves Iron Homeostatic Balance Disruption and Oxidative Stress Induction in Breast Cancer

Background: Vitamin D deficiency associates with high risk of breast cancer (BRCA) and increased cellular iron. Vitamin D exerts some of its anti-cancer effects by regulating the expression of key iron regulatory genes (IRGs). The association between vitamin D and cellular iron content in BRCA remains ambiguous. Herein, we addressed whether vitamin D signaling exerts a role in cellular iron homeostasis thereby affecting survival of breast cancer cells. Methods: Expression profile of IRGs in vitamin D-treated breast cancer cells was analyzed using publicly available transcriptomic datasets. After treatment of BRCA cell lines MCF-7 and MDA-MB-231 with the active form of vitamin D, labile iron content, IRGs protein levels, oxidative stress, and cell survival were evaluated. Results: Bioinformatics analysis revealed several IRGs as well as cellular stress relates genes were differentially expressed in BRCA cells. Vitamin D treatment resulted in cellular iron depletion and differentially affected the expression of key IRGs protein levels. Vitamin D treatment exerted oxidative stress induction and alteration in the cellular redox balance by increasing the synthesis of key stress-related markers. Collectively, these effects resulted in a significant decrease in BRCA cell survival. Conclusion: These findings suggest that vitamin D disrupts cellular iron homeostasis leading to oxidative stress induction and cell death.

Directing T-Cell Immune Responses for Cancer Vaccination and Immunotherapy

Cancer vaccination and immunotherapy revolutionised the treatment of cancer, a result of decades of research into the immune system in health and disease. However, despite recent breakthroughs in treating otherwise terminal cancer, only a minority of patients respond to cancer immunotherapy and some cancers are largely refractive to immunotherapy treatment. This is due to numerous issues intrinsic to the tumour, its microenvironment, or the immune system. CD4+ and CD8+ αβ T-cells emerged as the primary effector cells of the anti-tumour immune response but their function in cancer patients is often compromised. This review details the mechanisms by which T-cell responses are hindered in the setting of cancer and refractive to immunotherapy, and details many of the approaches under investigation to direct T-cell function and improve the efficacy of cancer vaccination and immunotherapy.

Diabetes and Colorectal Cancer Risk: A New Look at Molecular Mechanisms and Potential Role of Novel Antidiabetic Agents

Epidemiological data have demonstrated a significant association between the presence of type 2 diabetes mellitus (T2DM) and the development of colorectal cancer (CRC). Chronic hyperglycemia, insulin resistance, oxidative stress, and inflammation, the processes inherent to T2DM, also play active roles in the onset and progression of CRC. Recently, small dense low-density lipoprotein (LDL) particles, a typical characteristic of diabetic dyslipidemia, emerged as another possible underlying link between T2DM and CRC. Growing evidence suggests that antidiabetic medications may have beneficial effects in CRC prevention. According to findings from a limited number of preclinical and clinical studies, glucagon-like peptide-1 receptor agonists (GLP-1RAs) could be a promising strategy in reducing the incidence of CRC in patients with diabetes. However, available findings are inconclusive, and further studies are required. In this review, novel evidence on molecular mechanisms linking T2DM with CRC development, progression, and survival will be discussed. In addition, the potential role of GLP-1RAs therapies in CRC prevention will also be evaluated.

High prevalence of vitamin D deficiency in Asia: A systematic review and meta-analysis

Vitamin D deficiency is a worldwide health problem. However, the prevalence of vitamin D deficiency in Asian populations is unclear. The aims of our study were to investigate the prevalence of vitamin D deficiency and its association with different health outcomes in Asia. Searches for studies published from January 2009 to January 2021 were performed in the MEDLINE (via PubMed), EMBASE, and Web of Science databases. This study was registered in the PROSPERO database (CRD42021229841). In total, 472 studies with 746,564 subjects were included in the meta-analysis. The mean serum 25-hydroxyvitamin D (25[OH]D) concentration was 49.39 nmol/L; 20.93% of the participants had 25(OH)D levels <25 nmol/L, 22.82% had levels <30 nmol/L, 57.69% had levels <50 nmol/L, and 76.85% had levels <75 nmol/L. This review found that the prevalence of vitamin D deficiency in Asia is high. The factors significantly related to vitamin D deficiency were gender, age, altitude, region, and specific diseases (diabetes, cancer, fracture, systemic lupus erythematosus [SLE], fatty liver disease, osteopenia, thyroiditis, anemia, hepatitis, metabolic diseases, and dermatitis). These findings may serve as the foundation for more detailed public health strategies and policies on this issue.

Elshmiy R, ElSayed E, Shafik NF, O. Mahmoud M, Al-Daly M, Zaghloul MS. Vitamin D Receptor Gene Polymorphisms and the Risk of Chronic Hepatitis C Related Hepatocellular Carcinoma in Egyptian Population

Background:

Small percentage of hepatitis C (HCV) patients develop hepatocellular carcinoma (HCC) during their lifetime, suggesting that genetic factors might modulate HCC development. Numerous variations on the vitamin D receptor gene (VDR) have been recognized in human cancers. The majority of them cause VDR to be unable to bind to 1, 25-OH-D. The aim of the present work was to investigate the relation of VDR FokI (rs2228570), BsmI (rs3782905) and ApaI (rs7975232) gene polymorphisms and the risk of HCC development in chronic HCV Egyptian patients.

Methods:

A total of 311 Egyptian patients were enrolled for this study. They were divided into 3 groups: 103 patients with liver Cirrhosis, 107 patients with HCC and 101 normal healthy subjects as the control group. Human genomic DNA Extraction was carried out using QIAamp® DNA Blood Mini Kit (QIAGEN) Genotyping of VDR ApaI (rs7975232) single nucleotide polymorphism (SNP) was carried out using real-time PCR TaqMan allelic discrimination assay with allele-specific designed fluorescent MGB probes.

Results:

Patients with HCC had a higher frequency of ApaI CC genotype (P=0.035) CI (0.031-0.038). Patients with HCC carried a higher ratio of ApaI CC genotype compared to those with liver cirrhosis (x2=5.4 and P = 0.03) or controls (x2=6.8 and P = 0.01). Univariate analysis revealed that age, lower platelet count (<150×103/μL), higher AFP (>100 ng/ml), and ApaI CC genotype were the factors significantly associated with the development of HCC. Stepwise logistic regression analysis showed that all were independent predictors.

Conclusion:

ApaI CC VDR gene mutation is an independent risk factor for HCC development in Egyptian Cirrhotic HCV patients.

Association between Serum 25-Hydroxyvitamin D Level and Stroke Risk: An Analysis Based on the National Health and Nutrition Examination Survey

Background

To analyze the association between serum 25-hydroxyvitamin D level (25(OH)D) and stroke risk based on the National Health and Nutrition Examination Survey (NHANES).

Methods

Between 2007 and 2018, the baseline information of participants from NHNES was collected. Univariate analysis was used to identify the covariates. Multivariate logistic regression model was used to analyze the association between serum 25(OH)D level and the stroke risk.

Results

Of the 8,523 participants, there were 310 participants with stroke and 8,213 participants without stroke. The multivariate logistic analysis showed that serum 25(OH)D deficiency (odds ratio (OR): 1.993, 95% confidence intervals (CI): 1.141-3.481, and P = 0.012) was the significant risk factors for stroke. Subgroup analysis showed that non-Hispanic whites with serum 25(OH)D deficiency (OR: 2.501, 95% CI: 1.094-5.720, and P = 0.001) and insufficiency (OR: 1.853, 95% CI: 1.170-2.934, and P = 0.006) were associated with a higher risk of stroke than those with normal 25(OH)D levels.

Conclusions

Serum 25(OH)D deficiency may be associated with an increased risk of stroke.

The Effects of Vitamin D on Immune System and Inflammatory Diseases

Immune cells, including dendritic cells, macrophages, and T and B cells, express the vitamin D receptor and 1α-hydroxylase. In vitro studies have shown that 1,25-dihydroxyvitamin D, the active form of vitamin D, has an anti-inflammatory effect. Recent epidemiological evidence has indicated a significant association between vitamin D deficiency and an increased incidence, or aggravation, of infectious diseases and inflammatory autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis. However, the impact of vitamin D on treatment and prevention, particularly in infectious diseases such as the 2019 coronavirus disease (COVID-19), remains controversial. Here, we review recent evidence associated with the relationship between vitamin D and inflammatory diseases and describe the underlying immunomodulatory effect of vitamin D.

1,25(OH)2 D3 attenuates sleep disturbance in mouse models of Lewis lung cancer, in silico and in vivo

Many clinical studies have reported that patients diagnosed with cancer will suffer from sleep disturbance during their clinical process, especially among lung cancer patients, and this effect will not easily subside. 1,25-dihydroxy-vitamin-D3 [1,25(OH)2 D3 ], the activated form of vitamin D, can participate in neuronal differentiation and prevent damage to the nervous system. However, little is known about the potential therapeutic effects of cancer-related psychiatric symptoms. In light of this, we hypothesized that a low circulating level of vitamin D was related to sleep quality in the presence of a tumor, 1,25(OH)2 D3 may be an effective way to ameliorate sleep disturbance and neurochemical alterations along with the cancer progress. Male C57BL/6 mice were implanted with intracranial transmitters to monitor electroencephalogram and were subcutaneously inoculated with Lewis lung cancer cells. The results demonstrated that on Days 19-20, tumor-bearing mice displayed fragmented sleep, shortened wake phase, prolonged sleep in the non-rapid eye movement phase, and the levels of vitamin D-associated genes in the brain had changed a lot compared to control mice. Importantly, 1,25(OH)2 D3 treatment really effectively saved the sleep quality of tumor-bearing mice. We further explored and confirmed that 1,25(OH)2 D3 repressed tumor-induced neuroinflammation (IL-1β, TNF-α, IL-6, IL-10, IFN-γ, and IL-2), enhanced neurotrophic factors (brain-derived neurotrophic factor [BDNF], glialcellline-derived neurotrophic factor) and 5-HT system in the hippocampus, hypothalamus or cortex. A molecular docking approah manifested the ability of 1,25(OH)2 D3 to affect the activity of tryptophan hydroxylase 2 and BDNF. Together, our results suggested that 1,25(OH)2 D3 treatment may attenuate sleep disturbance in Lewis lung cancer-bearing mice, and become a promising strategy for treating cancer symptom clusters to ameliorate the quality of life of patients with cancer.

Impact of Genetic Polymorphisms on the Metabolic Pathway of Vitamin D and Survival in Non-Small Cell Lung Cancer

Vitamin D has been associated with risk, development, and progression of cancer. However, the genes involved in its metabolism are highly polymorphic, compromising its activity. The aim of this study is to evaluate the association between the gene polymorphisms involved in the metabolic pathway of vitamin D and survival in patients with non-small-cell lung cancer (NSCLC). The study was designed as an observational cohort which included 194 Caucasians patients from southern Spain with NSCLC. Real-time polymerase chain reaction was used to analyze the following polymorphisms: CYP27B1 rs4646536, rs3782130, and rs10877012; CYP24A1 rs6068816 and rs4809957; GC rs7041; CYP2R1 rs10741657; VDR rs1544410 (BsmI), rs11568820 (Cdx-2), rs2228570 (FokI), rs7975232 (ApaI), and rs731236 (TaqI). Progression-free survival (PFS) and overall survival were assessed. Cox regression showed that rs4646536 was associated with PFS in the general population (p = 0.0233) and in the non-resected NSCLC subgroup (p = 0.0233). In the resected NSCLC subgroup, rs11568820 was associated with OS (p = 0.0129) and rs7041 with PFS (p = 0.0447). In the non-resected NSCLC subgroup, rs6068816 was associated with PFS (p = 0.0048) and OS (p = 0.0089) and rs731236 and rs7975232 were associated with OS (p = 0.0005) and PFS (p = 0.0002), respectively. The other polymorphisms showed no effect on the results. The rs4646536, rs6068816, rs7041, rs11568820, rs731236, and rs7975232 polymorphisms are associated with survival in NSCLC and may have a substantial role as prognostic markers of the disease.

COVID-19 Mortality Risk Correlates Inversely with Vitamin D3 Status, and a Mortality Rate Close to Zero Could Theoretically Be Achieved at 50 ng/mL 25(OH)D3: Results of a Systematic Review and Meta-Analysis

BACKGROUND

Much research shows that blood calcidiol (25(OH)D3) levels correlate strongly with SARS-CoV-2 infection severity. There is open discussion regarding whether low D3 is caused by the infection or if deficiency negatively affects immune defense. The aim of this study was to collect further evidence on this topic.

METHODS

Systematic literature search was performed to identify retrospective cohort as well as clinical studies on COVID-19 mortality rates versus D3 blood levels. Mortality rates from clinical studies were corrected for age, sex, and diabetes. Data were analyzed using correlation and linear regression.

RESULTS

One population study and seven clinical studies were identified, which reported D3 blood levels preinfection or on the day of hospital admission. The two independent datasets showed a negative Pearson correlation of D3 levels and mortality risk (r(17) = -0.4154, p = 0.0770/r(13) = -0.4886, p = 0.0646). For the combined data, median (IQR) D3 levels were 23.2 ng/mL (17.4-26.8), and a significant Pearson correlation was observed (r(32) = -0.3989, p = 0.0194). Regression suggested a theoretical point of zero mortality at approximately 50 ng/mL D3.

CONCLUSIONS

The datasets provide strong evidence that low D3 is a predictor rather than just a side effect of the infection. Despite ongoing vaccinations, we recommend raising serum 25(OH)D levels to above 50 ng/mL to prevent or mitigate new outbreaks due to escape mutations or decreasing antibody activity.

Genetically predicted insomnia and lung cancer risk: a Mendelian randomization study

BACKGROUND

The relationship between insomnia and lung cancer is scanty. The Mendelian randomization approach provides the rationale for evaluating the potential causality between genetically-predicted insomnia and lung cancer risk.

METHODS

We extracted 148 insomnia-related single-nucleotide polymorphisms (SNPs) as instrumental variables (IVs) from published genome-wide association studies (GWASs). Summary data of individual-level genetic information of participants were obtained from the International Lung Cancer Consortium (ILCCO) (29,266 cases and 56,450 controls). MR analyses were performed using the inverse-variance-weighted approach, MR pleiotropy residual sum and outlier (MR-PRESSO) test, weighted median estimator, and MR-Egger regression. Sensitivity analyses were further performed using Egger intercept analysis, leave-one-out analysis, MR-PRESSO global test, and Cochran's Q test to verify the robustness of our findings.

RESULTS

The results of the MR analysis indicated an increased risk of lung cancer in insomnia patients (OR = 1.1671; 95% CI 1.0754-1.2666, p = 0.0002). The subgroup analyses showed increased risks of lung adenocarcinoma (OR = 1.1878; 95% CI 1.0594-1.3317, p = 0.0032) and squamous cell lung cancer (OR = 1.1595; 95% CI 1.0248-1.3119, p = 0.0188).

CONCLUSION

Our study indicated that insomnia is a causal risk factor in the development of lung cancer. Due to the lack of evidence on both the epidemiology and the mechanism level, more studies are needed to better elucidate the results of the study.

Vitamin D and COVID-19: A review on the role of vitamin D in preventing and reducing the severity of COVID-19 infection

Severe Acute Respiratory Syndrome Coronavirus‐2 (SARS‐CoV‐2) is a pathogenic coronavirus causing COVID‐19 infection. The interaction between the SARS‐CoV‐2 spike protein and the human receptor angiotensin‐converting enzyme 2, both of which contain several cysteine residues, is impacted by the disulfide‐thiol balance in the host cell. The host cell redox status is affected by oxidative stress due to the imbalance between the reactive oxygen/nitrogen species and antioxidants. Recent studies have shown that Vitamin D supplementation could reduce oxidative stress. It has also been proposed that vitamin D at physiological concentration has preventive effects on many viral infections, including COVID‐19. However, the molecular‐level picture of the interplay of vitamin D deficiency, oxidative stress, and the severity of COVID‐19 has remained unclear. Herein, we present a thorough review focusing on the possible molecular mechanism by which vitamin D could alter host cell redox status and block viral entry, thereby preventing COVID‐19 infection or reducing the severity of the disease.

Relative Efficacy of Vitamin D2 and Vitamin D3 in Improving Vitamin D Status: Systematic Review and Meta-Analysis

BACKGROUND

Widespread prevalence of vitamin D deficiency has been documented globally. Commonly used interventions to address this deficiency include supplementation and/or fortification with either ergocalciferol (vitamin D₂) or cholecalciferol (vitamin D₃), but the relative efficacy of these two vitamers is unclear. The current study aimed to evaluate the relative efficacy of ergocalciferol (vitamin D₂) and cholecalciferol (vitamin D₃) for raising the serum levels of vitamin D metabolites and functional indicators including serum parathyroid (PTH) levels, isometric muscle strength, hand grip strength and bone mineral density.

METHODS

Randomized and non-randomized controlled studies evaluating relative efficacy of ergocalciferol and cholecalciferol were systematically reviewed to synthesize quantitative and qualitative evidence as per the recommendations of according to "Preferred Reporting Items for Systematic reviews and Meta-analysis" guidelines. Search terms were constructed on the basis of the "participants", "intervention", "control", "outcome" and "study type" (PICOS) strategy to systematically search the popular electronic databases. Relevant data from studies meeting inclusion and exclusion criteria were extracted and analyzed. Meta-regression, subgroup and sensitivity analyses were performed to investigate the influence of study-level characteristics including intervention dosage, frequency of dosing, interval between the last dose and test for outcome assessment, participant characteristics and analytical methods.

RESULTS

Apparently healthy human participants (n = 1277) from 24 studies were included for meta-analysis. The quantitative analysis suggested higher efficacy of cholecalciferol than ergocalciferol in improving total 25(OH)D (mean difference: 15.69, 95%CI: 9.46 to 21.93 nmol/L) and reducing PTH levels, consistently across variable participant demographics, dosage and vehicle of supplementation. Meta-regression suggested smaller differences in the efficacy of cholecalciferol and ergocalciferol at lower doses. Average daily dose was the single significant predictor of effect size, as revealed by multivariate meta-regression analysis.

CONCLUSIONS

Compared to ergocalciferol, cholecalciferol intervention was more efficacious in improving vitamin D status (serum levels of total 25(OH)D and 25(OH)D₃) and regulating PTH levels, irrespective of the participant demographics, dosage and vehicle of supplementation.

1α,25-dihydroxyvitamin D3 protects retinal ganglion cells in glaucomatous mice

BACKGROUND

Glaucoma is an optic neuropathy characterized by loss of function and death of retinal ganglion cells (RGCs), leading to irreversible vision loss. Neuroinflammation is recognized as one of the causes of glaucoma, and currently no treatment is addressing this mechanism. We aimed to investigate the anti-inflammatory and neuroprotective effects of 1,25(OH)2D3 (1α,25-dihydroxyvitamin D3, calcitriol), in a genetic model of age-related glaucomatous neurodegeneration (DBA/2J mice).

METHODS

DBA/2J mice were randomized to 1,25(OH)2D3 or vehicle treatment groups. Pattern electroretinogram, flash electroretinogram, and intraocular pressure were recorded weekly. Immunostaining for RBPMS, Iba-1, and GFAP was carried out on retinal flat mounts to assess retinal ganglion cell density and quantify microglial and astrocyte activation, respectively. Molecular biology analyses were carried out to evaluate retinal expression of pro-inflammatory cytokines, pNFκB-p65, and neuroprotective factors. Investigators that analysed the data were blind to experimental groups, which were unveiled after graph design and statistical analysis, that were carried out with GraphPad Prism. Several statistical tests and approaches were used: the generalized estimated equations (GEE) analysis, t-test, and one-way ANOVA.

RESULTS

DBA/2J mice treated with 1,25(OH)2D3 for 5 weeks showed improved PERG and FERG amplitudes and reduced RGCs death, compared to vehicle-treated age-matched controls. 1,25(OH)2D3 treatment decreased microglial and astrocyte activation, as well as expression of inflammatory cytokines and pNF-κB-p65 (p < 0.05). Moreover, 1,25(OH)2D3-treated DBA/2J mice displayed increased mRNA levels of neuroprotective factors (p < 0.05), such as BDNF.

CONCLUSIONS

1,25(OH)2D3 protected RGCs preserving retinal function, reducing inflammatory cytokines, and increasing expression of neuroprotective factors. Therefore, 1,25(OH)2D3 could attenuate the retinal damage in glaucomatous patients and warrants further clinical evaluation for the treatment of optic neuropathies.

Lower Survival and Increased Circulating Suppressor Cells in Patients with Relapsed/Refractory Diffuse Large B-Cell Lymphoma with Deficit of Vitamin D Levels Using R-GDP Plus Lenalidomide (R2-GDP): Results from the R2-GDP-GOTEL Trial

The search of prognostic factors is a priority in diffuse large B-cell lymphoma (DLBCL) due to its aggressiveness. We have recently found that the level of circulating MDSCs is a good marker of survival in a translational study based on a trial (EudraCT Number: 2014-001620-29), using lenalidomide combined with R-GDP (rituximab plus gemcitabine, cisplatin, and dexamethasone). Since Vitamin D is a known immunomodulator, we have studied blood levels of these cell populations comparing patients with deficit of vitamin D levels (<15 ng/mL with those with normal levels >15 ng/mL. Mann-Whitney U test was used to compare cells distributions between groups, Wilcoxon test to compare cells distribution at different times and Spearman test to measure the association between cell populations. Patients with vitamin D deficit maintained the increased level of immune suppressor cells, whereas we observed a depletion of all immune suppressor cells in patients with normal vitamin D levels. In conclusion, we have confirmed the importance of vitamin D in the response to treatment in R/R DLBCL, suggesting that vitamin D deficit may be involved in the immune deficit of these patients, and thus, vitamin D supplementation in these patients may help to obtain a better response, warranting further investigation.

Plectin in Cancer: From Biomarker to Therapeutic Target

The cytolinker and scaffolding protein, plectin, has emerged as a potent driver of malignant hallmarks in many human cancers due to its involvement in various cellular activities contributing to tumorigenesis, including cancer cell proliferation, adhesion, migration, invasion, and signal transduction. Evidence shows that beyond plectin's diverse protein interactome, its cancer-specific mislocalization to the cell surface enables its function as a potent oncoprotein. As such, therapeutic targeting of plectin, its protein interactors, and, in particular, cancer-specific plectin (CSP) presents an attractive opportunity to impede carcinogenesis directly. Here, we report on plectin's differential gene and protein expression in cancer, explore its mutational profile, and discuss the current understanding of plectin's and CSP's biological function in cancer. Moreover, we review the landscape of plectin as a prognostic marker, diagnostic biomarker, and target for imaging and therapeutic modalities. We highlight how, beyond their respective biological importance, plectin's common overexpression in cancer and CSP's cancer-specific bioavailability underscore their potential as high-value druggable targets. We discuss how recent evidence of the potent anti-cancer effects of CSP therapeutic targeting opens the door for cell-surface mislocalized proteins as novel therapeutic targets.

Serum 25-hydroxyvitamin D, frailty, and mortality among the Chinese oldest old: Results from the CLHLS study

BACKGROUND AND AIMS

In this study, the aim is to explore whether frailty status modified the associations of serum 25(OH)D levels with all-cause and cause-specific mortality in the oldest old Chinese population.

METHODS AND RESULTS

A total of 1411 participants aged at least 80 years were enrolled in the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Information on serum 25(OH)D level, frailty status, and covariates were examined at baseline. All-cause and cause-specific mortality status were ascertained during the follow-up survey conducted in 2017-2018 by using the ICD-10 codes. Cox proportional hazard models with stratified analyses were performed to evaluate potential associations. Over a median follow-up of 3.2 years, 722 (51.2%) participants were deceased, including 202 deaths due to circulatory diseases, and 520 deaths due to noncirculatory causes. After multivariable adjustment, the lowest quartile of serum 25(OH)D levels (Hazard Ratios (95% Confidence Intervals), 1.85 (1.45-2.36), 1.85 (1.45-2.36), 1.73 (1.31-2.29), respectively) and frailty (Odd Ratios (95% Confidence Intervals), 1.91 (1.60-2.29), 2.67 (1.90-3.74), 1.64 (1.31-2.05)) were associated with significantly higher risk of all-cause mortality, circulatory mortality, and noncirculatory mortality, respectively. In addition, we observed significant interactions among 25(OH)D and frailty on the risk of all-cause and cause-specific mortality (all P-interaction < 0.001). Similar results were found in sensitivity analyses by excluding participants who died in the first year of follow-up and using clinical cutoffs of serum 25(OH)D levels.

CONCLUSION

Low serum 25(OH)D levels were associated with higher risk of all-cause and cause-specific mortality among the oldest old of the Chinese population, and the associations were significantly stronger in individuals with frailty.

Vitamin D Enhances Radiosensitivity of Colorectal Cancer by Reversing Epithelial-Mesenchymal Transition

Colorectal cancer (CRC) is often resistant to conventional therapies. Previous studies have reported the anticancer effects of vitamin D in several cancers, its role in radiotherapy (RT) remains unknown. We found that 1α, 25-dihydroxyvitamin D₃ (VD₃), the biologically active form of vitamin D, had antitumor effect on CRC and sensitized CRC cells to ionizing radiation (IR). VD₃ demonstrated synergistic effect in combination with IR, which were detected by colony formation and cell proliferation assay. Radiosensitivity restoration induced by VD₃ was associated with a series of phenotypes, including apoptosis, autophagy, and epithelial-mesenchymal transition (EMT). Using proteomics, “regulation of cell migration” and “cadherin” were found to be obviously enriched GO terms. Moreover, cystatin D and plasminogen activator inhibitor-1 (PAI-1), the differentially expressed proteins, were associated with EMT. Next, we confirmed the contributions of these two genes in enhancing IR sensitivity of CRC cells upon inhibition of EMT. As determined by proteomics, the mechanism underlying such sensitivity involved partially block of JAK/STAT3 signaling pathway. Furthermore, VD₃ also elicited sensitization to RT in xenograft CRC models without additional toxicity. Our study revealed that VD₃ was able to act in synergy with IR both in vitro and in vivo and could also confer radiosensitivity by regulating EMT, thereby providing a novel insight for elevating the efficacy of therapeutic regimens.

Dickkopf Proteins and Their Role in Cancer: A Family of Wnt Antagonists with a Dual Role

The Wnt signaling pathway regulates crucial aspects such as cell fate determination, cell polarity and organogenesis during embryonic development. Wnt pathway deregulation is a hallmark of several cancers such as lung, gastric and liver cancer, and has been reported to be altered in others. Despite the general agreement reached by the scientific community on the oncogenic potential of the central components of the pathway, the role of the antagonist proteins remains less clear. Deregulation of the pathway may be caused by overexpression or downregulation of a wide range of antagonist proteins. Although there is growing information related to function and regulation of Dickkopf (DKK) proteins, their pharmacological potential as cancer therapeutics still has not been fully developed. This review provides an update on the role of DKK proteins in cancer and possible potential as therapeutic targets for the treatment of cancer; available compounds in pre-clinical or clinical trials are also reviewed.

The Interdependency and Co-Regulation of the Vitamin D and Cholesterol Metabolism

Vitamin D and cholesterol metabolism overlap significantly in the pathways that contribute to their biosynthesis. However, our understanding of their independent and co-regulation is limited. Cardiovascular disease is the leading cause of death globally and atherosclerosis, the pathology associated with elevated cholesterol, is the leading cause of cardiovascular disease. It is therefore important to understand vitamin D metabolism as a contributory factor. From the literature, we compile evidence of how these systems interact, relating the understanding of the molecular mechanisms involved to the results from observational studies. We also present the first systems biology pathway map of the joint cholesterol and vitamin D metabolisms made available using the Systems Biology Graphical Notation (SBGN) Markup Language (SBGNML). It is shown that the relationship between vitamin D supplementation, total cholesterol, and LDL-C status, and between latitude, vitamin D, and cholesterol status are consistent with our knowledge of molecular mechanisms. We also highlight the results that cannot be explained with our current knowledge of molecular mechanisms: (i) vitamin D supplementation mitigates the side-effects of statin therapy; (ii) statin therapy does not impact upon vitamin D status; and critically (iii) vitamin D supplementation does not improve cardiovascular outcomes, despite improving cardiovascular risk factors. For (iii), we present a hypothesis, based on observations in the literature, that describes how vitamin D regulates the balance between cellular and plasma cholesterol. Answering these questions will create significant opportunities for advancement in our understanding of cardiovascular health.

Redox modulation of vitagenes via plant polyphenols and vitamin D: Novel insights for chemoprevention and therapeutic interventions based on organoid technology

Polyphenols are chemopreventive through the induction of nuclear factor erythroid 2 related factor 2 (Nrf2)-mediated proteins and anti-inflammatory pathways. These pathways, encoding cytoprotective vitagenes, include heat shock proteins, such as heat shock protein 70 (Hsp70) and heme oxygenase-1 (HO-1), as well as glutathione redox system to protect against cancer initiation and progression. Phytochemicals exhibit biphasic dose responses on cancer cells, activating at low dose, signaling pathways resulting in upregulation of vitagenes, as in the case of the Nrf2 pathway upregulated by hydroxytyrosol (HT) or curcumin and NAD/NADH-sirtuin-1 activated by resveratrol. Here, the importance of vitagenes in redox stress response and autophagy mechanisms, as well as the potential use of dietary antioxidants in the prevention and treatment of multiple types of cancer are discussed. We also discuss the possible relationship between SARS-CoV-2, inflammation and cancer, exploiting innovative therapeutic approaches with HT-rich aqueous olive pulp extract (Hidrox®), a natural polyphenolic formulation, as well as the rationale of Vitamin D supplementation. Finally, we describe innovative approaches with organoids technology to study human carcinogenesis in preclinical models from basic cancer research to clinical practice, suggesting patient-derived organoids as an innovative tool to test drug toxicity and drive personalized therapy.

Functional Meat Products as Oxidative Stress Modulators: A Review

High meat consumption has been associated with increased oxidative stress mainly due to the generation of oxidized compounds in the body, such as malondialdehyde, 4-hydroxy-nonenal, oxysterols, or protein carbonyls, which can induce oxidative damage. Meat products are excellent matrices for introducing different bioactive compounds, to obtain functional meat products aimed at minimizing the pro-oxidant effects associated with high meat consumption. Therefore, this review aims to summarize the concept and preparation of healthy and functional meat, which could benefit antioxidant status. Likewise, the key strategies regarding meat production and storage as well as ingredients used (e.g., minerals, polyphenols, fatty acids, walnuts) for developing these functional meats are detailed. Although most effort has been made to reduce the oxidation status of meat, newly emerging approaches also aim to improve the oxidation status of consumers of meat products. Thus, we will delve into the relation between functional meats and their health effects on consumers. In this review, animal trials and intervention studies are discussed, ascertaining the extent of functional meat products' properties (e.g., neutralizing reactive oxygen species formation and increasing the antioxidant response). The effects of functional meat products in the frame of diet-gene interactions are analyzed to 1) discover target subjects that would benefit from their consumption, and 2) understand the molecular mechanisms that ensure precision in the prevention and treatment of diseases, where high oxidative stress takes place. Long-term intervention-controlled studies, testing different types and amounts of functional meat, are also necessary to ascertain their positive impact on degenerative diseases.

A Potential Role of Vitamin D on Platelet Leukocyte Aggregation and Pathological Events in Sepsis: An Updated Review

Vitamin D deficiency and sepsis are both significant global health problems. Insufficient vitamin D is considered to be a pathogenically relevant factor of sepsis-related deaths; however, a causal relationship has not yet been demonstrated. Recently, vitamin D has been an exciting field of research owing to the identification of vitamin D receptors on many extra skeletal tissues and cells, suggesting an unexpected role on body physiology, beyond its effects on bone homeostasis. However, while the role of vitamin D on bone health is widely understood and has been successfully translated into clinical applications and public health policies, recent evidence supporting its role in other physiological and pathological processes has not been fully established. In sepsis, there is an induction of local intracellular vitamin D activity by most immune cells, including lymphocytes, macrophages, neutrophils, and dendritic cells, as well as vascular endothelial cells, to ensure efficient clearance of infective microorganisms and mediate anti-inflammatory and tolerogenic effects. The literature suggests an association between low vitamin D levels and sepsis, but clinical trials have yielded contradictory results. A greater understanding of this role may improve disease management. This article reviews the available knowledge regarding vitamin D in immune function, emerging literature regarding the association between its deficiency and sepsis, as well as presenting its potential effect on platelet leukocyte aggregations (PLAs), a significant pathology in sepsis. It also summarizes clinical trials involving vitamin D supplementation during critical illness and sepsis and addresses the impact of relevant factors of sepsis pathogenesis on the efficacy of vitamin D supplementation, which could contribute to the reported inconsistencies. Looking ahead, further studies are required to uncover the possible modulatory relationship between vitamin D and sepsis to define better cut-offs for its levels, proper timing of its administration, and the optimum dosage for best management.

Optimization of Automated Sample Preparation for Vitamin D Determination on a Biomek i7 Workstation

Vitamin D belongs to the fat-soluble vitamins and is an integral part of bone metabolism. In the human body, a decreased vitamin D level can be an additional risk factor for diseases like cancer, diabetes, and mental diseases. As a result, an enormous increase in the demand for vitamin D testing has been observed in recent years, increasing the demand for powerful methods for vitamin D determination at the same time.Automation is the key factor in increasing sample throughput. This study compares three fully automated sample preparation methods for the determination of 25(OH)D₂ and 25(OH)D₃ in plasma and serum samples. Starting from a semiautomated reference method, the method is tested manually and subsequently fully automated on the Biomek i7 Workstation by integrating a centrifuge and a positive pressure extractor into the workstation. Alternatively, the centrifugation for the separation of protein aggregates and supernatant is replaced by a filter plate. Finally, the sample throughput is further increased by using phospholipid removal cartridges. The results show that phospholipid removal significantly increases the recovery rates in liquid chromatography-mass spectrometry. With the phospholipid removal cartridges, recovery rates of 97.36% for 25(OH)D₂ and 102.5% for 25(OH)D₃ were achieved, whereas with the automated classic automated preparation method, the recovery rates were 83.31% for 25(OH)D₂ and 86.54% for 25(OH)D₃. In addition to the technical evaluation, the different methods were also examined with regard to their economic efficiency. Finally, the qualitative and quantitative performance of the developed methods is benchmarked with a selected semiautomatic reference method.

Cytoprotective Effect of Vitamin D on Doxorubicin-Induced Cardiac Toxicity in Triple Negative Breast Cancer

Background: Doxorubicin (Dox) is a first-line treatment for triple negative breast cancer (TNBC), but its use may be limited by its cardiotoxicity mediated by the production of reactive oxygen species. We evaluated whether vitamin D may prevent Dox-induced cardiotoxicity in a mouse TNBC model. Methods: Female Balb/c mice received rodent chow with vitamin D₃ (1500 IU/kg; vehicle) or chow supplemented with additional vitamin D₃ (total, 11,500 IU/kg). the mice were inoculated with TNBC tumors and treated with intraperitoneal Dox (6 or 10 mg/kg). Cardiac function was evaluated with transthoracic echocardiography. The cardiac tissue was evaluated with immunohistochemistry and immunoblot for levels of 4-hydroxynonenal, NAD(P)H quinone oxidoreductase (NQO1), C-MYC, and dynamin-related protein 1 (DRP1) phosphorylation. Results: At 15 to 18 days, the mean ejection fraction, stroke volume, and fractional shortening were similar between the mice treated with vitamin D + Dox (10 mg/kg) vs. vehicle but significantly greater in mice treated with vitamin D + Dox (10 mg/kg) vs. Dox (10 mg/kg). Dox (10 mg/kg) increased the cardiac tissue levels of 4-hydroxynonenal, NQO1, C-MYC, and DRP1 phosphorylation at serine 616, but these increases were not observed with vitamin D + Dox (10 mg/kg). A decreased tumor volume was observed with Dox (10 mg/kg) and vitamin D + Dox (10 mg/kg). Conclusions: Vitamin D supplementation decreased Dox-induced cardiotoxicity by decreasing the reactive oxygen species and mitochondrial damage, and did not decrease the anticancer efficacy of Dox against TNBC.

Vitamin D: A Pleiotropic Hormone with Possible Psychotropic Activities

BACKGROUND

After the recognition of the efficacy of cod-liver oil in rickets at the end of the eighteenth century, and the isolation and synthesis of the liposoluble vitamin D in 1931, its mode of actions and functions were deeply explored. Biochemical studies permitted to identify five forms of vitamin D, called D1, D2, D3, D4 and D5, differing in ultrastructural conformation and origin, with vitamin D2 (ergocalciferol) and D3 (cholecalciferol) representing the active forms. In the last decades especially, a constantly increasing bulk of data highlighted how vitamin D could regulate several activities and processes.

AIMS

The aim of the present paper was to review and comment on the literature on vitamin D, with a focus on its possible role in the pathophysiology of neuropsychiatric disorders.

DISCUSSION

Available literature indicates that vitamin D regulates a variety of processes in humans and in the central nervous system. Vitamin D deficiency is associated with an enhanced pro-inflammatory state, and formation of Aβ oligomers that might contribute to the cognitive decline typical of the elderly age and, perhaps, dementia. More in general, vitamin D is supposed to play a crucial role in neuroinflammation processes that are currently hypothesized to be involved in the pathophysiology of different psychiatric disorders, such as major depression, bipolar disorders, obsessive-compulsive disorders and psychosis.

CONCLUSION

It is conceivable that vitamin D supplementation might pave the way towards "natural" treatments of a broad range of neuropsychiatric disorders, or at least be useful to boost response to psychotropic drugs in resistant cases.

Vitamin D Toxicity Managed with Peritoneal Dialysis

Vitamin D deficiency is a global health issue that afflicts more than one billion children and adults worldwide. Vitamin D supplementation has increased over the years, whether through medical prescriptions, over-the-counter, or online purchasing. This is driven by a more recognized association between vitamin D sufficiency status and lower risk of cancer. In addition, more recently, it is used as a potential prophylactic and treatment for COVID-19 infection. This can lead to toxicity from overingestion. While rare, it has been reported in the literature. In this case report, we present a 75-year-old man with severe hypercalcemia secondary to vitamin D toxicity managed with peritoneal dialysis. He presented with biochemical evidence of hypercalcemia, acute kidney injury, and pancreatitis. Workup for his hypercalcemia led to the diagnosis of vitamin D toxicity as shown by a level greater than 200 ng/dL (Ref: 20-50 ng/mL) was confirmed by liquid chromatography-mass spectroscopy. Cornerstone medical management of hypercalcemia was provided which included aggressive intravenous fluid hydration, intravenous diuretics, calcitonin, bisphosphonate, and corticosteroid therapy. At every interruption of therapy, calcium levels trended upward. A thorough literature review yielded the finding of a sole case report from 1966 presented at the Third International Congress of Nephrology, in which peritoneal dialysis was used in the management of vitamin D toxicity and hypercalcemia. This modality is established to cause vitamin D deficiency. In collaboration with the nephrology team, 10 sessions of peritoneal dialysis were undertaken with resolution of hypercalcemia and downtrend in 25-hydroxyvitamin D levels as measured by dilution.

Knocking out the Vitamin D Receptor Enhances Malignancy and Decreases Responsiveness to Vitamin D3 Hydroxyderivatives in Human Melanoma Cells

Simple Summary

Active forms of vitamin D3, including 1,25(OH)₂D3, 20(OH)D3 and 1,20(OH)₂D3, inhibited cell proliferation, migration rate and the ability to form colonies and spheroids in the wild-type melanoma cell line, while cells with the vitamin D receptor (VDR) silenced showed an increased but not complete resistance to their action. Furthermore, silencing of the VDR in melanoma cells enhanced their proliferation as well as spheroid and colony formation and increased their migration rate. Previous clinicopathological studies have shown an inverse correlation between VDR expression, melanoma progression and poor outcome of the disease. Thus, the expression of VDR is not only necessary for the inhibition of melanoma growth by active forms of vitamin D, but the VDR can also function as a melanoma tumor suppressor gene.

Abstract

Vitamin D3 is not only involved in calcium and phosphate metabolism in humans, but it can also affect proliferation and differentiation of normal and cancer cells, including melanoma. The mechanism of the anti-cancer action of vitamin D3 is not fully understood. The nuclear vitamin D receptor (VDR) is crucial for the phenotypic effects of vitamin D hydroxyderivatives. VDR expression shows an inverse correlation with melanoma progression and poor outcome of the disease. In this study we knocked out the VDR in a human melanoma cell line using CRISPR methodology. This enhanced the proliferation of melanoma cells grown in monolayer culture, spheroids or colonies and their migration. Activated forms of vitamin D, including classical 1,25(OH)₂D3, 20(OH)D3 and 1,20(OH)₂D3, inhibited cell proliferation, migration rate and the ability to form colonies and spheroids in the wild-type melanoma cell line, while VDR KO cells showed a degree of resistance to their action. These results indicate that expression of VDR is important for the inhibition of melanoma growth induced by activated forms of vitamin D. In conclusion, based on our previous clinicopathological analyses and the current study, we suggest that the VDR can function as a melanoma tumor suppressor gene.

Is Vitamin D Deficiency Related to Increased Cancer Risk in Patients with Type 2 Diabetes Mellitus?

There is mounting evidence that type 2 diabetes mellitus (T2DM) is related with increased risk for the development of cancer. Apart from shared common risk factors typical for both diseases, diabetes driven factors including hyperinsulinemia, insulin resistance, hyperglycemia and low grade chronic inflammation are of great importance. Recently, vitamin D deficiency was reported to be associated with the pathogenesis of numerous diseases, including T2DM and cancer. However, little is known whether vitamin D deficiency may be responsible for elevated cancer risk development in T2DM patients. Therefore, the aim of the current review is to identify the molecular mechanisms by which vitamin D deficiency may contribute to cancer development in T2DM patients. Vitamin D via alleviation of insulin resistance, hyperglycemia, oxidative stress and inflammation reduces diabetes driven cancer risk factors. Moreover, vitamin D strengthens the DNA repair process, and regulates apoptosis and autophagy of cancer cells as well as signaling pathways involved in tumorigenesis i.e., tumor growth factor β (TGFβ), insulin-like growth factor (IGF) and Wnt-β-Cathenin. It should also be underlined that many types of cancer cells present alterations in vitamin D metabolism and action as a result of Vitamin D Receptor (VDR) and CYP27B1 expression dysregulation. Although, numerous studies revealed that adequate vitamin D concentration prevents or delays T2DM and cancer development, little is known how the vitamin affects cancer risk among T2DM patients. There is a pressing need for randomized clinical trials to clarify whether vitamin D deficiency may be a factor responsible for increased risk of cancer in T2DM patients, and whether the use of the vitamin by patients with diabetes and cancer may improve cancer prognosis and metabolic control of diabetes.

Vitamin D3 potentiates the nephroprotective effects of metformin in a rat model of metabolic syndrome: role of AMPK/SIRT1 activation and DPP-4 inhibition

The current study aimed to investigate the molecular mechanisms of metformin and vitamin D3-induced nephroprotection in a metabolic syndrome (MetS) rat model, evaluating the capacity of vitamin D3 to potentiate metformin action. MetS was induced by 10% fructose in drinking water and 3% salt in the diet. After 6 weeks, serum lipid profile and uric acid were measured, an oral glucose tolerance test (OGTT) was performed, and kidney function was investigated. In conjunction with the same concentrations of fructose and salt feeding, MetS rats with significant weight gain, dyslipidemia, hyperuricemia, and dysglycemia were treated orally with metformin (200 mg/kg), vitamin D3 (10 µg/kg), or both daily for 6 weeks. At the end of the study period, anthropometrical parameters were recorded, OGTT was reperformed, urine and blood samples were collected, and tissue samples were harvested at sacrifice. MetS rats showed dramatically declined renal function, enhanced intrarenal oxidative stress and inflammation, and extravagant renal histopathological damage with interstitial fibrosis. Metformin and vitamin D3 significantly reversed all the aforementioned deleterious effects in MetS rats. The study has verified the nephroprotective effects of metformin and vitamin D3 in MetS, accentuating the critical role of AMP-activated protein kinase/sirtuin-1 activation and dipeptidyl peptidase-4 inhibition. Given the synergistic effects of the combination, vitamin D3 is worth being investigated as an additional therapeutic agent for preventing MetS-induced nephropathy.

Vitamin D: Possible Therapeutic Roles in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a unique type of liver cancer instigated by underlying liver diseases. Pre-clinical evidence suggests that HCC progression, like other cancers, could be aided by vitamin D deficiency. Vitamin D is a lipid-soluble hormone usually obtained through sunlight. Vitamin D elucidates its biological responses by binding the vitamin D receptor; thus, promoting skeletal mineralization, and maintain calcium homeostasis. Other reported Vitamin D functions include specific roles in proliferation, angiogenesis, apoptosis, inflammation, and cell differentiation. This review highlighted studies on vitamin D's functional roles in HCC and discussed the specific therapeutic targets from various in vivo, in vitro and clinical studies over the years. Furthermore, it described recent advancements in vitamin D's anticancer effects and its metabolizing enzymes' roles in HCC development. In summary, the review elucidated specific vitamin D-associated target genes that play critical functions in the inhibition of tumorigenesis through inflammation, oxidative stress, invasion, and apoptosis in HCC progression.

Immunomodulatory Effects of Vitamin D Supplementation in a Deficient Population

In addition to its canonical functions, vitamin D has been proposed to be an important mediator of the immune system. Despite ample sunshine, vitamin D deficiency is prevalent (>80%) in the Middle East, resulting in a high rate of supplementation. However, the underlying molecular mechanisms of the specific regimen prescribed and the potential factors affecting an individual's response to vitamin D supplementation are not well characterized. Our objective is to describe the changes in the blood transcriptome and explore the potential mechanisms associated with vitamin D3 supplementation in one hundred vitamin D-deficient women who were given a weekly oral dose (50,000 IU) of vitamin D3 for three months. A high-throughput targeted PCR, composed of 264 genes representing the important blood transcriptomic fingerprints of health and disease states, was performed on pre and post-supplementation blood samples to profile the molecular response to vitamin D3. We identified 54 differentially expressed genes that were strongly modulated by vitamin D3 supplementation. Network analyses showed significant changes in the immune-related pathways such as TLR4/CD14 and IFN receptors, and catabolic processes related to NF-kB, which were subsequently confirmed by gene ontology enrichment analyses. We proposed a model for vitamin D3 response based on the expression changes of molecules involved in the receptor-mediated intra-cellular signaling pathways and the ensuing predicted effects on cytokine production. Overall, vitamin D3 has a strong effect on the immune system, G-coupled protein receptor signaling, and the ubiquitin system. We highlighted the major molecular changes and biological processes induced by vitamin D3, which will help to further investigate the effectiveness of vitamin D3 supplementation among individuals in the Middle East as well as other regions.

Vitamin D deficiency exacerbates hepatic oxidative stress and inflammation during acetaminophen-induced acute liver injury in mice

Several experiments confirmed that vitamin D3 protected against acetaminophen (APAP)-induced acute liver injury (ALI). This research aimed to evaluate the influence of vitamin D deficiency (VDD) on APAP-induced ALI. In VDD and VDD + APAP groups, mice were fed with VDD diet. In APAP and VDD + APAP groups, mice were intraperitoneally injected with a sublethal dose of APAP (150 mg/kg). A sublethal dose of APAP caused a slight elevation of ALT and AST. Interestingly, APAP-induced elevation of ALT and AST was aggravated in VDD-fed mice. APAP-induced hepatic necrosis was exacerbated in VDD-fed mice. In addition, APAP-induced hepatocyte death, measured using TUNEL assay, was exacerbated in VDD-fed mice. Additional experiment showed that APAP-induced hepatic GSH depletion and lipid peroxidation were exacerbated in VDD-fed mice. Moreover, APAP-induced upregulation of antioxidant genes, such as hepatic heme oxygenase-1 (Ho-1), glutathione peroxidase (Gshpx), superoxide dismutase 1 (Sod1) and catalase enzymes (Cat), was aggravated in VDD-fed mice. Although a sublethal dose of APAP did not cause hepatic inflammation, hepatic proinflammatory cytokines and chemokines, such as Tnf-α, Kc, Mcp-1 and Mip2, were upregulated in VDD-fed mice treated with APAP. These results provide experimental data that VDD exacerbates hepatic oxidative stress and inflammation during APAP-induced ALI.

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.

Inhibition of calcitriol inactivating enzyme CYP24A1 gene expression by flavonoids in hepatocellular carcinoma cells under normoxia and hypoxia

A vast number of epidemiological, preclinical and in vitro experimental data strongly indicate the anticancer potential of calcitriol, the biologically active form of vitamin D. However, for the implementation of a vitamin D based cancer therapy the increased deactivation of calcitriol in cancer cells by overexpressed CYP24A1 hydroxylase should be suppressed. Inhibition of this enzyme expression or activity nowadays is considered as important aspect of anticancer therapeutic strategies. Herein, we investigated the impact of genistein, biochanin A, formonentin and kaempferol on the expression of the CYP24A1 gene induced by calcitriol in hepatocellular cancer cells Huh7 under normoxia (21%O₂) or hypoxia (1%O₂). We demonstrate that calcitriol induces CYP24A1 under normoxia and hypoxia, but this induction is significantly more potent under hypoxia, the typical microenvironment of solid tumors. In the presence of isoflavones genistein, biochanin A and formononetin, this induction is abrogated to the control levels under normoxia, while under hypoxia there is some differentiation in suppression efficacy between these compounds with genistein ≥ biochanin > formononetin. At the same time, kaempferol turned out to be completely ineffective in the suppression of CYP24A1 gene expression.

Immune Response: A Missed Opportunity Between Vitamin D and Radiotherapy

Radiotherapy (RT) is a mainstay treatment in several types of cancer and acts by mediating various forms of cancer cell death, although it is still a large challenge to enhance therapy efficacy. Radiation resistance represents the main cause of cancer progression, therefore, overcoming treatment resistance is now the greatest challenge for clinicians. Increasing evidence indicates that immune response plays a role in reprogramming the radiation-induced tumor microenvironment (TME). Intriguingly, radiation-induced immunosuppression possibly overwhelms the ability of immune system to ablate tumor cells. This induces an immune equilibrium, which, we hypothesize, is an opportunity for radiosensitizers to make actions. Vitamin D has been reported to act in synergistic with RT by potentiating antiproliferative effect induced by therapeutics. Additionally, vitamin D can also regulate the TME and may even lead to immunostimulation by blocking immunosuppression following radiation. Previous reviews have focused on vitamin D metabolism and epidemiological trials, however, the synergistic effect of vitamin D and existing therapies remains unknown. This review summarizes vitamin D mediated radiosensitization, radiation immunity, and vitamin D-regulated TME, which may contribute to more successful vitamin D-adjuvant radiotherapy.

Control of T Cell Metabolism by Cytokines and Hormones

Dynamic, coordinated changes in metabolic pathway activity underpin the protective and inflammatory activity of T cells, through provision of energy and biosynthetic precursors for effector functions, as well as direct effects of metabolic enzymes, intermediates and end-products on signaling pathways and transcriptional mechanisms. Consequently, it has become increasingly clear that the metabolic status of the tissue microenvironment directly influences T cell activity, with changes in nutrient and/or metabolite abundance leading to dysfunctional T cell metabolism and interlinked immune function. Emerging evidence now indicates that additional signals are integrated by T cells to determine their overall metabolic phenotype, including those arising from interaction with cytokines and hormones in their environment. The impact of these on T cell metabolism, the mechanisms involved and the pathological implications are discussed in this review article.

Synergistic Effects of Exercise Training and Vitamin D Supplementation on Mitochondrial Function of Cardiac Tissue, Antioxidant Capacity, and Tumor Growth in Breast Cancer in Bearing-4T1 Mice

Both regular exercise training and vitamin D consumption are beneficial for patients with cancer. The study investigated the effects of interval exercise training (IET) or/and vitamin D supplementation on the gene expression involved in mitochondrial function of heart tissue, tumor size, and total antioxidant capacity (TAC) in breast cancer (BC) model mice. We assigned random 40 female NMRI mice to five equal groups (n = 8); the healthy control group (H.C), cancer control group (Ca.C), cancer with the vitamin D group (Ca.VD), cancer exercise group (Ca.Ex), and cancer exercise along with the vitamin D group (Ca.Ex.VD). Forty-eight hours after treatment, we anesthetized the animals and performed the isolation of heart tissue and blood serum for further studies. The results showed that the lowest mean body weight at the end of the treatments was related to Ca.C (p = 0.001). Vitamin D treatment alone has increased tumor volume growth by approximately 23%; in contrast, co-treatment with exercise and vitamin D inhibited tumor growth in mice (P = 0.001), compared with the cancer control (12%). TAC levels were higher in the group that received both vitamin D and exercise training (Ca.Ex.VD) than in the other treatment groups (Ca.VD and Ca.Ex) (p = 0.001). In cardiac tissue, vitamin D treatment induces an elevation significantly of the mRNA expression of Pgc1-α, Mfn-1, and Drp-1 genes (p = 0.001). The study has shown the overexpression of vitamin D in female mice, and synergistic effects of IET with vitamin D on weight loss controlling, antitumorigenesis, improvement of antioxidant defense, and the modulation of gene expression. The synergistic responses were likely by increasing mitochondrial fusion and TAC to control oxidative stress. We recommended being conducted further studies on mitochondrial dynamics and biogenesis focusing on risk factors of cardiovascular disease (CVD) in patients with BC.

Aerosol 1,25-dihydroxyvitamin D3 supplementation: A strategy to boost anti-tumor innate immune activity

BACKGROUND

1,25-dihydroxyvitamin D3 [1,25(OH)2D3] plays a role in calcium homeostasis but can also exert immunomodulatory effects. In lungs, characterized by a particular immunosuppressive environment primarily due to the presence of alveolar macrophages (AM), 1,25(OH)2D3 has been shown to favor the immune response against pathogens. Here, we explored the ability of aerosolized 1,25(OH)2D3 to locally promote an anti-tumor phenotype in alveolar macrophages (AM) in the treatment of lung metastases.

METHODS

Cytotoxicity assay has been used to assess the capability of AM, in vitro treated of not with 1,25(OH)2D3, to stimulate NK cells. Sulforhodamine B (SRB) assay has been used to assess the effect of 1,25(OH)2D3 on MC-38 and B16 tumor cells in vitro growth. 1,25(OH)2D3 was aerosolized in immunocompetent mouse models to evaluate the effect of local administration of 1,25(OH)2D3 on in vivo growth of MC-38 and B16 tumor cells within lungs and on infiltrating immune cells.

RESULTS

In vitro incubation of naïve AM with 1,25(OH)2D3 improved their ability to stimulate NK cell cytotoxicity. In vivo aerosolized 1,25(OH)2D3 significantly reduced the metastatic growth of MC-38 colon carcinoma, a tumor histotype that frequently metastasizes to lung in human. Immune infiltrate obtained from digested lungs of 1,25(OH)2D3-treated mice bearing MC-38 metastases revealed an increased expression of MHCII and CD80 on AM and an up-modulation of CD69 expression on effector cells that paralleled a strong increased ability of these cells to kill MC-38 tumor in vitro.

CONCLUSIONS

Together, these data show that aerosol delivery can represent a feasible and novel approach to supplement 1,25(OH)2D3 directly to the lungs promoting the activation of local immunity against cancer.

Lung cancer risk in patients with multiple sclerosis: a Mendelian randomization analysis

BACKGROUND

The relationship of multiple sclerosis (MS) with lung cancer is under debate. Conventional observational studies have reported conflicting findings, but such studies are susceptible to confounding and reverse causation. With a Mendelian Randomization approach, we were able to evaluate the causality between MS and lung cancer.

METHODS

According to published genome-wide association studies (GWASs), we obtained 35 MS-related single-nucleotide polymorphisms, which were used as instrumental variables in our study. Summary data of individual-level genetic information were obtained from the International Lung Cancer Consortium (ILCCO), with a total of 15,861 controls and 11,348 cases; the latter is composed of patients with lung adenocarcinoma and squamous cell lung cancer. The inverse variance-weighted method was applied to estimate the causation between MS and lung cancer. To further evaluate the pleiotropy, the MR-Egger and Weighted median methods were implemented.

RESULTS

The results of MR analysis suggested a causal effect of MS on lung cancer incidence, with evidence of an increased risk for overall lung cancer [odds ratio (OR): 1.0648; 95% confidence interval (CI): 1.0163-1.1156; p = 0.0082]. However, subgroup analyses showed no significant causal relationships between MS and lung adenocarcinoma (OR = 1.0716; 95% CI 0.9840-1.1671, p = 0.1119) and squamous cell lung cancer (OR = 1.0284; 95% CI 0.9575-1.1045, p = 0.4424). In addition, no pleiotropy was found in our study.

CONCLUSION

Our study indicated that MS is a causal risk factor in the development of lung cancer. Further work is needed to elucidate the potential mechanisms.

Vitamin D and new insights into pathophysiology of type 2 diabetes

Deficiency in vitamin D plays a role in the onset and development of insulin resistance (IR) and type 2 diabetes (T2DM). A normal level of vitamin D is able to reduce low grade inflammation, which is a major process in inducing insulin resistance. It is also engaged in maintaining low resting levels of reactive species and radicals, normal Ca²⁺ signaling, a low expression of pro-inflammatory cytokines but increased formation of anti-inflammatory cytokines. Vitamin D is also able to prevent hypermethylation (of DNA) and consequent functional inactivation of many genes, as well as other epigenetic alterations in β cells and in other insulin-sensitive peripheral tissues, mainly liver, adipose tissue and muscle. Vitamin D deficiency thus belongs to key factors accelerating the development of IR and consequently T2DM as well. However, vitamin D supplementation aimed at the control of glucose homeostasis in humans showed controversial effects. As a result, further studies are running to gain more detailed data needed for the full clinical utilization of vitamin D supplementation in the prevention and treatment of T2DM. Until new results are published, supplementation with high doses of vitamin D deficiency is not recommended. However, prevention of vitamin D deficiency and its correction are highly desired.

Potential immunomodulatory effects of vitamin D in the prevention of severe coronavirus disease 2019: An ally for Latin America (Review)

Currently, the world is under a pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for coronavirus disease 2019 (COVID-19). This disease is characterized by a respiratory syndrome that can progress to an acute respiratory distress syndrome. To date, limited effective therapies are available for the prevention or treatment of COVID-19; therefore, it is necessary to propose novel treatment options with immunomodulatory effects. Vitamin D serves functions in bone health and has been recently reported to exert protective effects against respiratory infections. Observational studies have demonstrated an association between vitamin D deficiency and a poor prognosis of COVID-19; this is alarming as vitamin D deficiency is a global health problem. In Latin America, the prevalence of vitamin D deficiency is unknown, and currently, this region is in the top 10 according to the number of confirmed COVID-19 cases. Supplementation with vitamin D may be a useful adjunctive treatment for the prevention of COVID-19 complications. The present review provides an overview of the current knowledge of the potential immunomodulatory effects of vitamin D in the prevention of COVID-19 and sets out vitamin D recommendations for the Latin American population.

Vitamin-related phenotypic adaptation to exposomal factors: The folate-vitamin D-exposome triad

The biological role of two key vitamins, folic acid and vitamin D is so fundamental to life processes, it follows that their UV sensitivity, dietary abundance (both key exposomal factors) and variability in dependent genes will modify their functional efficacy, particularly in the context of maintaining the integrity and function of genome and epigenome. This article therefore examines folate and vitamin D-related phenotypic adaptation to environmental factors which vary across the human life cycle as well as over an evolutionary time-scale. Molecular mechanisms, key nutrigenomic factors, phenotypic maladaptation and evolutionary models are discussed.

Evaluation of the potential anticancer activity of different vitamin D metabolites on colorectal and breast cancer cell lines

OBJECTIVES

Vitamin D is very important for calcium and mineral metabolism, and many hypotheses appear to link sunlight exposure with cancer risk and prognosis. As many studies supported the antitumor effect of vitamin D we wanted to investigate the potential effect of multiple vitamin D metabolites.

METHODS

This study compared the anticancer effect of three inactive forms of vitamin D₃ which are; cholecalciferol, alfacalcidol, and calcifediol on two human cancer cell lines colorectal cancer (CaCo II) and breast cancer (MCF-7). All were examined after 24, 48, and 72 h continuous exposure using a colorimetric assay (MTT) seeded in 96-multiwell plates. Doxorubicin anticancer used as a standard agent for comparison, while normal skin fibroblast cells (HDFa) was used as our negative control. IC₅₀ values were calculated as indication of antitumor effect.

RESULTS

Broad-spectrum of cytotoxicity with IC₅₀ values ranging from 4 to 200 μM were found. Alfacalcidol was the most potent cytotoxic agents on colorectal cancer (CaCo II) and breast cancer (MCF-7) compared to cholecalciferol, and calcifediol. Both, alfacalcidol and calcifediol were more cytotoxic than cholecalciferol on the tested cell lines as they are partially active metabolites. Breast cancer (MCF-7) was the most sensitive to all metabolites at all-time intervals with the best IC₅₀ values of 4.35 μM ± 1.06 after 72 h continuous exposure of alfacalcidol.

CONCLUSIONS

Vitamin D metabolites are a potential option for cancer treatment along with or an alternative to chemo-therapeutics although extensive preclinical studies are required to prove this effect.

Vitamin D Modulation of the Innate Immune Response to Paediatric Respiratory Pathogens Associated with Acute Lower Respiratory Infections

Vitamin D is an essential component of immune function and childhood deficiency is associated with an increased risk of acute lower respiratory infections (ALRIs). Globally, the leading childhood respiratory pathogens are Streptococcus pneumoniae, respiratory syncytial virus and the influenza virus. There is a growing body of evidence describing the innate immunomodulatory properties of vitamin D during challenge with respiratory pathogens, but recent systematic and unbiased synthesis of data is lacking, and future research directions are unclear. We therefore conducted a systematic PubMed literature search using the terms “vitamin D” and “Streptococcus pneumoniae” or “Respiratory Syncytial Virus” or “Influenza”. A priori inclusion criteria restricted the review to in vitro studies investigating the effect of vitamin D metabolites on human innate immune cells (primary, differentiated or immortalised) in response to stimulation with the specified respiratory pathogens. Eleven studies met our criteria. Despite some heterogeneity across pathogens and innate cell types, vitamin D modulated pathogen recognition receptor (PRRs: Toll-like receptor 2 (TLR2), TLR4, TLR7 and nucleotide-binding oligomerisation domain-containing protein 2 (NOD2)) expression; increased antimicrobial peptide expression (LL-37, human neutrophil peptide (HNP) 1-3 and β-defensin); modulated autophagosome production reducing apoptosis; and modulated production of inflammatory cytokines (Interleukin (IL) -1β, tumour necrosis factor-α (TNF-α), interferon-ɣ (IFN-ɣ), IL-12p70, IFN-β, Regulated on Activation, Normal T cell Expressed (RANTES), IL-10) and chemokines (IL-8 and C-X-C motif chemokine ligand 10 (CXCL10)). Differential modulation of PRRs and IL-1β was reported across immune cell types; however, this may be due to the experimental design. None of the studies specifically focused on immune responses in cells derived from children. In summary, vitamin D promotes a balanced immune response, potentially enhancing pathogen sensing and clearance and restricting pathogen induced inflammatory dysregulation. This is likely to be important in controlling both ALRIs and the immunopathology associated with poorer outcomes and progression to chronic lung diseases. Many unknowns remain and further investigation is required to clarify the nuances in vitamin D mediated immune responses by pathogen and immune cell type and to determine whether these in vitro findings translate into enhanced immunity and reduced ALRI in the paediatric clinical setting.

Evaluation of Vitamin D-Binding Protein Gene Polymorphism and its Plasma Concentration in Kurdish Patients With Breast Cancer in Sanandaj, Iran

Background: Several studies have indicated that polymorphism in vitamin D pathway genes is associated with breast cancer (BC) risk. Vitamin D-binding protein (VDBP) is a vital element in the metabolism of the vitamin D. VDBP carries the serum 25(OH) D3 to cells to promote vitamin D biological functions, such as cell proliferation and apoptosis. Missense SNP (rs.7041) is a common polymorphism in VDBP gene, which shows ethnic-specific allele frequencies. Objectives: This study presents the correlation of the rs7041 (Asp432Glu) gene polymorphism and plasma concentrations of VDBP in Kurdish patients with BC in Sanandaj, Iran. Methods: This cross-sectional study included 44 premenopausal BC patients and 44 healthy subjects. Plasma VDBP concentration was measured by enzyme-linked immunosorbent assay (ELISA). The VDBP (rs7041) was genotyped by polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP). Results: VDBP level was associated with a non-significant risk of BC (P=0.397). Frequencies of individuals with VDBP (rs7041) TT, TG, and GG genotypes were 13.6%, 52.2%, and 34.09% in case group and 11.3%, 79.5%, and 9.9% in control group, respectively. Genotype GG associated with increased susceptibility to developing BC (odds ratio [OR]=5.172, CI: 1.555-17.2, P=0.007). There was a significant reverse correlation between GT genotype and BC (OR=0.282, 95% CI: 0.110-0.722, P=0.008) Conclusion: The changes in the vitamin D pathway may increase susceptibility to develop BC in the Iranian Kurdish population.

The influence of omega-3 supplementation on vitamin D levels in humans: a systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

Inconsistencies exist with regard to the influence of omega-3 supplementation on 25-hydroxyvitamin D (25(OH)D) levels, which could be attributed to many factors, such as the duration and dose of omega-3 supplementation, and individuals' baseline 25(OH)D levels. Therefore, to address the inconsistencies, we conducted a systematic review and dose-response meta-analysis to accurately determine the effect of omega-3 supplementation on 25(OH)D levels in humans.

METHODS

We performed a comprehensive literature search in Web of Science, PubMed/Medline, Scopus, and Embase databases from inception up to January 2020. We included only randomized controlled trials (RCTs). We used weighted mean difference (WMD) with 95% confidence interval (CI) to assess the influence of omega-3 supplementation on serum 25(OH)D levels using the random-effects model.

RESULTS

Our pooled results of 10 RCTs demonstrated an overall significant increase in 25(OH)D levels following omega-3 intake (WMD = 3.77 ng/ml, 95% CI: 1.29, 6.25). In addition, 25(OH)D levels were significantly increased when the intervention duration lasted >8 weeks and when the baseline serum 25(OH)D level was ˂20 ng/ml. Moreover, omega-3 intake ≤1000 mg/day resulted in higher 25(OH)D levels compared to omega-3 intake >1000 mg/day.

CONCLUSION

In conclusion, omega-3 supplementation increased 25(OH)D concentrations, particularly with dosages ≤1000 mg/day and intervention durations >8 weeks.