Correlation of a unique 220-kDa protein with vitamin D sensitivity in glioma cells

Complementary and alternative medicine in children with diffuse intrinsic pontine glioma-A SIOPE DIPG Network and Registry study

INTRODUCTION

Diffuse intrinsic pontine glioma (DIPG) is a rare and aggressive childhood brainstem malignancy with a 2-year survival rate of <10%. This international survey study aims to evaluate the use of complementary and alternative medicine (CAM) in this patient population.

METHODS

Parents and physicians of patients with DIPG were asked to participate in a retrospective online survey regarding CAM use during time of illness.

RESULTS

Between January and May 2020, 120 parents and 75 physicians contributed to the online survey. Most physicians estimated that <50% of their patients used CAM, whereas 69% of the parents reported using CAM to treat their child during time of illness. Cannabis was the most frequently used form of CAM, followed by vitamins and minerals, melatonin, curcumin, and boswellic acid. CAM was mainly used with the intention of direct antitumor effect. Other motivations were to treat side effects of chemotherapy or to increase comfort of the child. Children diagnosed from 2016 onwards were more likely to use CAM (χ²  = 6.08, p = .014). No significant difference was found between CAM users and nonusers based on ethnicity (χ²  = 4.18, p = .382) or country of residence (χ²  = 9.37, p = .154). Almost 50% of the physicians do not frequently ask their patients about possible CAM use.

CONCLUSION

This survey demonstrates that worldwide, a considerable number of patients with DIPG use CAM. Physicians should be more aware of potential CAM use and actively discuss the topic. In addition, more research is needed to gain knowledge about possible anticancer effects of CAM and (positive/negative) interactions with conventional therapies.

Antitumoral effects of the alkynylphosphonate analogue of calcitriol EM1 on glioblastoma multiforme cells

Glioblastoma multiforme (GBM) is the worst and most common brain tumor, characterized by high proliferation and invasion rates. The current standard treatment is mainly based on chemoradiotherapy and this approach has slightly improved patient survival. Thus, novel strategies aimed at prolonging the survival and ensuring a better quality of life are necessary. In the present work, we investigated the antitumoral effect of the novel analogue of calcitriol EM1 on GBM cells employing in vitro, in silico, and in vivo assays. In vitro, we demonstrated that EM1 treatment selectively decreases the viability of murine and human tumor cells without affecting that of normal human astrocytes. The analysis of the mechanisms showed that EM1 produces cell cycle arrest in the T98G cell line, which is accompanied by an increase in p21, p27, p57 protein levels and a decrease in cyclin D1, p-Akt-S473, p-ERK1/2 and c-Jun expression. Moreover, EM1 treatment also exerts in GBM cells anti-migratory effects and decreases their invasive capacity by a reduction in MMP-9 proteolytic activity. In silico, we demonstrated that EM1 is able to bind to the vitamin D receptor with greater affinity than calcitriol. Finally, we showed that EM1 treatment of nude mice administered at 50ug/kg body weight during 21days neither induces hypercalcemia nor toxicity effects. In conclusion, all the results indicate the potential of EM1 analogue as a promising therapeutic alternative for GBM treatment.

Vitamin D receptor expression is associated with improved overall survival in human glioblastoma multiforme

Vitamin D and its analogs have been shown to display anti-proliferative effects in a wide variety of cancer types including glioblastoma multiforme (GBM). These anticancer effects are mediated by its active metabolite, 1α, 25-dihydroxyvitamin D3 (calcitriol) acting mainly through vitamin D receptor (VDR) signaling. In addition to its involvement in calcitriol action, VDR has also been demonstrated to be useful as a prognostic factor for some types of cancer. However, to our knowledge, there are no studies evaluating the expression of VDR protein and its association with outcome in gliomas. Therefore, we investigated VDR expression by using immunohistochemical analysis in human glioma tissue microarrays, and analyzed the association between VDR expression and clinico-pathological parameters. We further investigated the effects of genetic and pharmacologic modulation of VDR on survival and migration of glioma cell lines. Our data demonstrate that VDR is increased in tumor tissues when compared with VDR in non-malignant brains, and that VDR expression is associated with an improved outcome in patients with GBM. We also show that both genetic and pharmacologic modulation of VDR modulates GBM cellular migration and survival and that VDR is necessary for calcitriol-mediated effects on migration. Altogether these results provide some limited evidence supporting a role for VDR in glioma progression.

Vitamin D in fetal brain development

In this review we will provide a concise summary of the evidence implicating a role for vitamin D in the developing brain. Vitamin D is known to affect a diverse array of cellular functions. Over the past 10 years data has emerged implicating numerous ways in which this vitamin could also affect the developing brain including its effects on cell differentiation, neurotrophic factor expression, cytokine regulation, neurotransmitter synthesis, intracellular calcium signaling, anti-oxidant activity, and the expression of genes/proteins involved in neuronal differentiation, structure and metabolism. Dysfunction in any of these processes could adversely affect development. Although there are many ways to study the effects of vitamin D on the developing CNS in vivo, we will concentrate on one experimental model that has examined the impact of the dietary absence of vitamin D in utero. Finally, we discuss the epidemiological data that suggests that vitamin D deficiency either in utero or in early life may have adverse neuropsychiatric implications.

Developmental vitamin D deficiency causes abnormal brain development

There is now clear evidence that vitamin D is involved in brain development. Our group is interested in environmental factors that shape brain development and how this may be relevant to neuropsychiatric diseases including schizophrenia. The origins of schizophrenia are considered developmental. We hypothesised that developmental vitamin D (DVD) deficiency may be the plausible neurobiological explanation for several important epidemiological correlates of schizophrenia namely: (1) the excess winter/spring birth rate, (2) increased incidence of the disease in 2nd generation Afro-Caribbean migrants and (3) increased urban birth rate. Moreover we have published two pieces of direct epidemiological support for this hypothesis in patients. In order to establish the "Biological Plausibility" of this hypothesis we have developed an animal model to study the effect of DVD deficiency on brain development. We do this by removing vitamin D from the diet of female rats prior to breeding. At birth we return all dams to a vitamin D containing diet. Using this procedure we impose a transient, gestational vitamin D deficiency, while maintaining normal calcium levels throughout. The brains of offspring from DVD-deficient dams are characterised by (1) a mild distortion in brain shape, (2) increased lateral ventricle volumes, (3) reduced differentiation and (4) diminished expression of neurotrophic factors. As adults, the alterations in ventricular volume persist and alterations in brain gene and protein expression emerge. Adult DVD-deficient rats also display behavioural sensitivity to agents that induce psychosis (the NMDA antagonist MK-801) and have impairments in attentional processing. In this review we summarise the literature addressing the function of vitamin D on neuronal and non-neuronal cells as well as in vivo results from DVD-deficient animals. Our conclusions from these data are that vitamin D is a plausible biological risk factor for neuropsychiatric disorders and that vitamin D acts as a neurosteroid with direct effects on brain development.

Procollagen Alpha 1 Type I: A Potential Aide in Histopathological Grading of Glioma

Collagen type I production has been shown to play a role in malignant transformation. We examined procollagen type I expression in brain tumors and with histopathological grading. Expression levels of procollagen alpha 1 type 1 were determined in 5 glioma cell lines by RT-PCR, Northern, and Western blot analysis. In addition, 41 primary brain tumors and 2 metastatic lung cancers to the brain were examined by PCR. Of the 5 glioma cell line analyzed, 3 (glioma 1, SW-1783 and U-118) expressed procollagen alpha 1 type I and were sensitive to vitamin D3 (VD3). In contrast, 2 of the cell lines (U-373 and T-98G) lacked procollagen alpha 1 type 1 expression. In patients' samples, 14 of 15 anaplastic and low grade gliomas expressed procollagen alpha 1 type I, and 12 of the 14 expressed high levels. In contrast, only 12 of 21 high grade gliomas from patients expressed procollagen alpha 1 type1 and among these, only 4 of the 12 expressed high levels. Thus, there is an inversed correlation between procollagen alpha 1 type 1 expression and histopathological grading (R2=- 0.56, p=0.0005). Our data suggest that procollagen alpha 1 type I expression occurs more commonly in intermediate and low grade gliomas and may assist in histopathological grading.

Neurosteroid hormone vitamin D and its utility in clinical nutrition

PURPOSE OF REVIEW

Vitamin D is a seco-steroid hormone with multiple functions in the nervous system. We discuss clinical and experimental evidence of the role of vitamin D in normal and pathological brain functions, and analyze the relative importance of vitamin D-modulated brain mechanisms at different stages of life. We also outline perspectives for the use of vitamin D in clinical nutrition to prevent or treat various brain disorders.

RECENT FINDINGS

Numerous brain dysfunctions are linked to vitamin D deficits and/or dysfunctions of its receptors. In both animals and humans, vitamin D serves as an important endogenous and/or exogenous regulator of neuroprotection, antiepileptic and anticalcification effects, neuro-immunomodulation, interplay with neurotransmitters and hormones, modulation of behaviors, brain ageing, and some other, less-explored, brain processes.

SUMMARY

Vitamin D emerges as an important neurosteroid hormone in the brain, with a strong potential for age-specific applications in clinical nutrition.

Vitamin D3 Metabolism in Human Glioblastoma Multiforme: Functionality of CYP27B1 Splice Variants, Metabolism of Calcidiol, and Effect of Calcitriol

PURPOSE

A better understanding of the vitamin D(3) metabolism is required to evaluate its potential therapeutic value for cancers. Here, we set out to contribute to the understanding of vitamin D(3) metabolism in glioblastoma multiforme.

EXPERIMENTAL DESIGN

We did nested touchdown reverse transcription-PCR (RT-PCR) to identify CYP27B1 splice variants and real-time RT-PCR to quantify the expression of CYP27B1. A cell line was treated with calcitriol to determine the effect on the expression of CYP27B1, 1alpha,25-dihydroxyvitamin D(3)-24-hydroxylase (CYP24), and vitamin D(3) receptor (VDR). We generated three antibodies for the specific detection of CYP27B1 and splice variants. High-performance TLC was done to determine the endogenous CYP27B1 activity and the functionality of CYP27B1 splice variants. Using WST-1 assay, we determined the effect of vitamin D(3) metabolites on proliferation.

RESULTS

We report a total of 16 splice variants of CYP27B1 in glioblastoma multiforme and a different expression of CYP27B1 and variants between glioblastoma multiforme and normal tissues. We found preliminary evidence for enzymatic activity of endogenous CYP27B1 in glioblastoma multiforme cell cultures but not for the functionality of the splice variants. By adding calcitriol, we found a proliferative effect for some cell lines depending on the dose of calcitriol. The administration of calcitriol led to an elevated expression of CYP27B1 and CYP24 but left the expression of the VDR unaltered.

CONCLUSIONS

Our findings show that glioblastoma multiforme cell lines metabolize calcidiol. In addition, we show various effects mediated by calcitriol. We found a special vitamin D(3) metabolism and mode of action in glioblastoma multiforme that has to be taken into account in future vitamin D(3)-related therapies.

New clues about vitamin D functions in the nervous system

Accumulating data have provided evidence that 1 alpha,25 dihydroxyvitamin D(3) [1,25-(OH)(2)D(3)] is involved in brain function. Thus, the nuclear receptor for 1,25-(OH)(2)D(3) has been localized in neurons and glial cells. Genes encoding the enzymes involved in the metabolism of this hormone are also expressed in brain cells. The reported biological effects of 1,25-(OH)(2)D(3) in the nervous system include the biosynthesis of neurotrophic factors and at least one enzyme involved in neurotransmitter synthesis. 1,25-(OH)(2)D(3) can also inhibit the synthesis of inducible nitric oxide synthase and increase glutathione levels, suggesting a role for the hormone in brain detoxification pathways. Neuroprotective and immunomodulatory effects of this hormone have been described in several experimental models, indicating the potential value of 1,25-(OH)(2)D(3) pharmacological analogs in neurodegenerative and neuroimmune diseases. In addition, 1,25-(OH)(2)D(3) induces glioma cell death, making the hormone of potential interest in the management of brain tumors. These results reveal previously unsuspected roles for 1,25-(OH)(2)D(3) in brain function and suggest possible areas of future research.