Tumor Expression of Vitamin D Receptor and Breast Cancer Histopathological Characteristics and Prognosis

Vitamin D status in female dogs with mammary gland tumors

BACKGROUND

Little information exists about vitamin D status in bitches with mammary tumors.

OBJECTIVES

To determine whether low plasma vitamin D concentrations are found in bitches with mammary tumors.

ANIMALS

Eighty-five client-owned bitches with mammary tumors (n = 21 benign, n = 64 malignant) and 39 age-matched healthy bitches.

METHODS

Case-control study. Plasma ionized and total calcium, phosphorus, magnesium, urea, creatinine, albumin, total proteins, alanine aminotransferase, alkaline phosphatase, parathyroid hormone (PTH), calcitriol (1,25-dihydroxyvitamin D), and 25-hydroxyvitamin D concentrations were measured in all bitches at the time of clinical diagnosis and before any treatments. Statistical analysis was performed to compare variables among groups (control, benign, and malignant).

RESULTS

No significant differences were found when plasma 25-hydroxyvitamin D concentrations in bitches with malignant (148.9 [59.9] ng/mL) and benign mammary tumors (150.1 [122.3] ng/mL) were compared with control group (129.9 [54.5] ng/mL). Parathyroid hormone was significantly higher in bitches with malignant (19.9 [20.5] pg/mL), and benign mammary tumors (14.6 [14.9] pg/mL) compared with control group (7.5 [7.5] pg/mL; P < .01). Only the presence of mammary tumors (P < .01) and age (P = .04; adjusted R2 = .22) was significant in predicting PTH.

CONCLUSIONS

Bitches with mammary tumors do not have low 25-hydroxyvitamin D concentrations thus vitamin D supplementation is unlikely to be useful for prevention of mammary tumors in bitches.

VDR is a potential prognostic biomarker and positively correlated with immune infiltration: a comprehensive pan-cancer analysis with experimental verification

The vitamin D receptor (VDR) is a transcription factor that mediates a variety of biological functions of 1,25-dihydroxyvitamin D3. Although there is growing evidence of cytological and animal studies supporting the suppressive role of VDR in cancers, the conclusion is still controversial in human cancers and no systematic pan-cancer analysis of VDR is available. We explored the relationships between VDR expression and prognosis, immune infiltration, tumor microenvironment, or gene set enrichment analysis (GSEA) in 33 types of human cancers based on multiple public databases and R software. Meanwhile, the expression and role of VDR were experimentally validated in papillary thyroid cancer (PTC). VDR expression decreased in 8 types and increased in 12 types of cancer compared with normal tissues. Increased expression of VDR was associated with either good or poor prognosis in 13 cancer types. VDR expression was positively correlated with the infiltration of cancer-associated fibroblasts, macrophages, or neutrophils in 20, 12, and 10 cancer types respectively and this correlation was experimentally validated in PTC. Increased VDR expression was associated with increased percentage of stromal or immune components in tumor microenvironment (TME) in 24 cancer types. VDR positively and negatively correlated genes were enriched in immune cell function and energy metabolism pathways, respectively, in the top 9 highly lethal tumors. Additionally, VDR expression was increased in PTC and inhibited cell proliferation and migration. In conclusion, VDR is a potential prognostic biomarker and positively correlated with immune infiltration as well as stromal or immune components in TME in multiple human cancers.

Investigating the level of vitamin D receptor gene expression in two tumoral and healthy breast tissues in breast cancer patients and its association with prognostic factors

BACKGROUND

Breast cancer is one of the most common cancers known among women. This study aimed to investigate the level of vitamin D receptor gene expression in two tumoral and healthy breast tissues in breast cancer patients and its association with prognostic factors.

METHODS

This descriptive cross-sectional study was conducted in 2022 on 50 patients with high suspicion of breast cancer who were candidates for mastectomy and lumpectomy in a learning hospital. From the patients, two tissue samples were prepared, and there was a total of 100 samples. The samples were subjected to H/E staining and evaluated by a pathologist. The presence or absence of malignancy in each sample was confirmed by two pathologists, and HER2/ER/PR indices were determined. Descriptive and analytical statistical methods and SPSS version 22 software were used.

RESULTS

The average age of the patients was 51.60 ± 11.22 years old, and the average tumor size was 3.17 ± 1.28. Most tumors were grade 2 (48%). The expression of HER2, ER, and PR was positive in 24, 64, and 54%, respectively. The largest number of cases were in stage 2A. The expression level of vitamin D receptor (VDR) gene in healthy tissue (2.08 ± 1.01) was higher than tumoral tissue (0.25 ± 1.38) (P = 0.001). In tumoral and healthy tissue, VDR expression was not significant according to tumor grade, HER2, ER, PR, LVI, LN, disease stage, age, and tumor size.

CONCLUSIONS

The expression level of VDR in healthy tissue was significantly higher than tumoral tissue. However, there was no significant relationship between VDR and tumor grade, HER2, ER, PR, LVI, LN, disease stage, age, and tumor size.

Calcitriol Treatment Decreases Cell Migration, Viability and β-Catenin Signaling in Oral Dysplasia

Nearly 90% of oral cancers are characterized as oral squamous cell carcinoma (OSCC), representing the sixth most common type of cancer. OSCC usually evolves from oral potentially malignant disorders that, in some cases, are histologically consistent with a oral dysplasia. The levels of 1α,25 dihydroxyvitamin D3 (1,25-(OH)2D3; calcitriol), the active form of vitamin D3, have been shown to be decreased in patients with oral dysplasia and OSCC. Moreover, treatment with 1,25-(OH)2D3 has been proven beneficial in OSCC by inhibiting the Wnt/β-catenin pathway, a signaling route that promotes cell migration, proliferation, and viability. However, whether this inhibition mechanism occurs in oral dysplasia is unknown. To approach this question, we used dysplastic oral keratinocyte cultures and oral explants (ex vivo model of oral dysplasia) treated with 1,25-(OH)2D3 for 48 h. Following treatment with 1,25-(OH)2D3, both in vitro and ex vivo models of oral dysplasia showed decreased levels of nuclear β-catenin by immunofluorescence (IF) and immunohistochemistry (IHC). Consistently, reduced protein and mRNA levels of the Wnt/β-catenin target gene survivin were observed after treatment with 1,25-(OH)2D3. Moreover, 1,25-(OH)2D3 promoted membranous localization of E-cadherin and nuclear localization of vitamin D receptor (VDR). Functionally, DOK cells treated with 1,25-(OH)2D3 displayed diminished cell migration and viability in vitro.

The Vitamin D Receptor as a Prognostic Marker in Breast Cancer-A Cohort Study

Previous research has indicated an association between the presence of the vitamin D receptor (VDR) in breast cancer tissue and a favorable prognosis. This study aimed to further evaluate the prognostic potential of VDR located in the nuclear membrane or nucleus (liganded). The VDR protein levels were analyzed using immunohistochemistry in tumor samples from 878 breast cancer patients from Lund, Sweden, included in the Breast Cancer and Blood Study (BCBlood) from October 2002 to June 2012. The follow-up for breast cancer events and overall survival was recorded until 30 June 2019. Univariable and multivariable survival analyses were conducted, both with complete case data and with missing data imputed using multiple imputation by chained equations (MICE). Tumor-specific positive nuclear membrane VDR(num) staining was associated with favorable tumor characteristics and a longer breast cancer free interval (BCFI; HR: 0.64; 95% CI: 0.44-0.95) and overall survival (OS; HR: 0.52; 95% CI: 0.34-0.78). Further analyses indicated that VDRnum status also was predictive of overall survival when investigated in relation to ER status. There were significant interactions between VDR and invasive tumor size (Pinteraction = 0.047), as well as mode of detection (Pinteraction = 0.049). VDRnum was associated with a longer BCFI in patients with larger tumors (HR: 0.36; 95% CI: 0.14-0.93) or clinically detected tumors (HR: 0.28; 95% CI: 0.09-0.83), while no association was found for smaller tumors and screening-detected tumors. Further studies are suggested to confirm our results and to evaluate whether VDR should and could be used as a prognostic and targetable marker in breast cancer diagnostics.

Dual effect of vitamin D3 on breast cancer-associated fibroblasts

BACKGROUND

Cancer-associated fibroblasts (CAFs) play an important role in the tumor microenvironment. Despite the well-known in vitro antitumoral effect of vitamin D3 (VD3), its impact on breast CAFs is almost unknown. In this study, we analyzed the ex vivo effects of calcitriol on CAFs isolated from breast cancer tissues.

METHODS

CAFs were cultured with 1 and 10 nM calcitriol and their phenotype; gene expression, protein expression, and secretion were assessed. Calcitriol-treated CAFs-conditioned media (CM) were used to analyze the effect of CAFs on the migration and protein expression of MCF-7 and MDA-MB-231 cells.

RESULTS

Tumor tissues from VD3-deficient patients exhibited lower levels of β-catenin and TGFβ1, along with higher levels of CYP24A1 compared to VD3-normal patients. In VD3-deficient patients, CAF infiltration was inversely associated with CYP24A1 levels and positively correlated with OPN levels. Calcitriol diminished CAFs' viability, but this effect was weaker in premenopausal and VD3-normal patients. Calcitriol reduced mRNA expression of CCL2, MMP9, TNC, and increased PDPN, SPP1, and TIMP1. It also decreased the secretion of CCL2, TNC, and the activity of MMP-2, while increasing cellular levels of TIMP1 in CAFs from all patient groups. In nonmetastatic and postmenopausal patients, PDPN surface expression increased, and CAFs CM from these groups decreased MCF-7 cell migration after ex vivo calcitriol treatment. In premenopausal and VD3-deficient patients, calcitriol reduced IDO1 expression in CAFs. Calcitriol-treated CAFs CM from these patients decreased OPN expression in MCF-7 and/or MDA-MB-231 cells. However, in premenopausal patients, calcitriol-treated CAFs CM also decreased E-cadherin expression in both cell lines.

CONCLUSION

The effects of calcitriol on breast CAFs, both at the gene and protein levels, are complex, reflecting the immunosuppressive or procancer properties of CAFs. The anticancer polarization of CAFs following ex vivo calcitriol treatment may result from decreased CCL2, TNC (gene and protein), MMP9, and MMP-2, while the opposite effect may result from increased PDPN, TIMP1 (gene and protein), and SPP1. Despite these multifaceted effects of calcitriol on molecule expression, CAFs' CMs from nonmetastatic and postmenopausal patients treated ex vivo with calcitriol decreased the migration of MCF-7 cells.

Progress in the Understanding of Estrogen Receptor Alpha Signaling in Triple-Negative Breast Cancer: Reactivation of Silenced ER-α and Signaling through ER-α36

Triple-negative breast cancer (TNBC) is an aggressive tumor that accounts for approximately 15% of total breast cancer cases. It is characterized by poor prognosis and high rate of recurrence compared to other types of breast cancer. TNBC has a limited range of treatment options that include chemotherapy, surgery, and radiation due to the absence of estrogen receptor alpha (ER-α) rendering hormonal therapy ineffective. However, possible targets for improving the clinical outcomes in TNBC exist, such as targeting estrogen signaling through membranous ER-α36 and reactivating silenced ER-α. It has been shown that epigenetic drugs such as DNA methyltransferase and histone deacetylase inhibitors can restore the expression of ER-α. This reactivation of ER-α, presents a potential strategy to re-sensitize TNBC to hormonal therapy. Also, this review provides up-to-date information related to the direct involvement of miRNA in regulating the translation of ER-α mRNA. Specific epi-miRNAs can regulate ER-α expression indirectly by post-transcriptional targeting of mRNAs of enzymes that are involved in DNA methylation and histone deacetylation. Furthermore, ER-α36, an alternative splice variant of ER-α66, is highly expressed in ER-negative breast tumors and activates MAPK/ERK pathway, promoting cell proliferation, escaping apoptosis, and enhancing metastasis. In the future, these recent advances may be helpful for researchers working in the field to obtain novel treatment options for TNBC, utilizing epigenetic drugs and epi-miRNAs that regulate ER-α expression. Also, there is some evidence to suggest that drugs that decrease the expression of ER-α36 may be effective in treating TNBC.

Vitamin D3 Inhibits the Viability of Breast Cancer Cells In Vitro and Ehrlich Ascites Carcinomas in Mice by Promoting Apoptosis and Cell Cycle Arrest and by Impeding Tumor Angiogenesis

The incidence of aggressive and resistant breast cancers is growing at alarming rates, indicating a necessity to develop better treatment strategies. Recent epidemiological and preclinical studies detected low serum levels of vitamin D in cancer patients, suggesting that vitamin D may be effective in mitigating the cancer burden. However, the molecular mechanisms of vitamin D3 (cholecalciferol, vit-D3)-induced cancer cell death are not fully elucidated. The vit-D3 efficacy of cell death activation was assessed using breast carcinoma cell lines in vitro and a widely used Ehrlich ascites carcinoma (EAC) breast cancer model in vivo in Swiss albino mice. Both estrogen receptor-positive (ER+, MCF-7) and -negative (ER-, MDA-MB-231, and MDA-MB-468) cell lines absorbed about 50% of vit-D3 in vitro over 48 h of incubation. The absorbed vit-D3 retarded the breast cancer cell proliferation in a dose-dependent manner with IC50 values ranging from 0.10 to 0.35 mM. Prolonged treatment (up to 72 h) did not enhance vit-D3 anti-proliferative efficacy. Vit-D3-induced cell growth arrest was mediated by the upregulation of p53 and the downregulation of cyclin-D1 and Bcl2 expression levels. Vit-D3 retarded cell migration and inhibited blood vessel growth in vitro as well as in a chorioallantoic membrane (CAM) assay. The intraperitoneal administration of vit-D3 inhibited solid tumor growth and reduced body weight gain, as assessed in mice using a liquid tumor model. In summary, vit-D3 cytotoxic effects in breast cancer cell lines in vitro and an EAC model in vivo were associated with growth inhibition, the induction of apoptosis, cell cycle arrest, and the impediment of angiogenic processes. The generated data warrant further studies on vit-D3 anti-cancer therapeutic applications.

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

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

Prevalence and Relevance of Vitamin D Deficiency in Newly Diagnosed Breast Cancer Patients: A Pilot Study

(1) Background: Vitamin D plays an important role in many types of cancer. It was the aim of this study to analyze serum 25-hydroxyvitamin D (25(OH)D) levels in newly diagnosed breast cancer patients, and the association with prognostic and lifestyle factors. (2) Methods: 110 non-metastatic breast cancer patients were included in the prospective observational “BEGYN” study at Saarland University Medical Center between September 2019 and January 2021. At the initiation visit, serum 25(OH)D levels were measured. Clinicopathological data on prognosis, nutrition, and lifestyle were extracted from data files and obtained using a questionnaire. (3) Results: Median serum 25(OH)D in breast cancer patients was 24 ng/mL (range 5–65 ng/mL), with 64.8% of patients being vitamin D deficient. 25(OH)D was higher among patients that reported the use of vitamin D supplements (43 ng/mL versus 22 ng/mL; p < 0.001), and in summer compared to other seasons (p = 0.03). Patients with moderate vitamin D deficiency were less likely to have triple negative breast cancer (p = 0.047). (4) Conclusions: Routinely measured vitamin D deficiency is common in breast cancer patients and needs to be detected and treated. However, our results do not support the hypothesis that vitamin D deficiency may be a main prognostic factor for breast cancer.

Association Between Expression of Vitamin D Receptor and Insulin-Like Growth Factor 1 Receptor Among Breast Cancer Patients

Background

Vitamin D receptor (VDR) and insulin-like growth factor 1 receptor (IGF1R) are known to be involved in breast cancer (BC) progression. Our previous work reported a correlation of differential localization of IGF1R with hormone receptor status in BC. A recent report described VDR and IGF1R as potential indicators of BC prognosis, but their interplay was not discussed. The present study focused on understanding the association of VDR expression with IGF1R activation, different molecular markers, and subtypes of BC.

Methods

A retrospective study was designed to evaluate the VDR expression among 48 BC patients pathologically diagnosed as invasive BC and were surgically treated at Sharjah Breast Care Center, University Hospital Sharjah (UHS), United Arab Emirates (UAE). Formalin-fixed paraffin-embedded (FFPE) tumor blocks with appropriate clinicopathological data were subjected to immunohistochemistry (IHC), and VDR protein expression was interpreted based on the staining intensity (SI) and the percentage of the positively stained cells (PP).

Results

Nearly 44% of cases in the study were vitamin D deficient. A positive VDR expression with strong intensity (score > 4) was seen in 27 cases (56.3%). The expression pattern for VDR was equally distributed in cytoplasm and nucleus. For the IGF1R intensity, 24 cases (50%) of total cohort showed strong expression. A significant association was detected between IGF1R and VDR expression (P = 0.031).

Conclusions

The present study identified positive association between IGF1R and VDR expression where most of the cases with strong VDR expression displayed strong IGF1R expression. These findings may contribute to current understanding on the role of VDR in BC and its interaction with IGF1R.

Vitamin D Receptor Expression Is Significantly Decreased in Bone Metastases Compared to Matched Primary Breast Cancer Tumours

There is ample evidence today that vitamin D signalling via the vitamin D receptor (VDR) plays a pivotal role in cancer growth and metastasis. The aim of this study was to analyse VDR expression of primary breast cancer and corresponding bone metastases tissue samples. Collectively, 15 sample pairs and 11 samples of patients that did not develop metastases were analysed histologically for VDR expression (n = 41). Overall, VDR expression was significantly lower in bone metastases compared to primary tumour samples (p < .0001). Downregulation of the VDR in breast cancer cells may define a critical turning point in oncogenesis that accelerates cancer cell dissemination and metastases.

Intestinal vitamin D receptor protects against extraintestinal breast cancer tumorigenesis

The microbiota plays critical roles in regulating the function and health of the intestine and extraintestinal organs. A fundamental question is whether an intestinal-microbiome-breast axis exists during the development of breast cancer. If so, what are the roles of host factors? Vitamin D receptor (VDR) involves host factors and the human microbiome. Vdr gene variation shapes the human microbiome, and VDR deficiency leads to dysbiosis. We hypothesized that intestinal VDR protects hosts against tumorigenesis in the breast. We examined a 7,12-dimethylbenzanthracene (DMBA)-induced breast cancer model in intestinal epithelial VDR knockout (VDRΔIEC) mice with dysbiosis. We reported that VDRΔIEC mice with dysbiosis are more susceptible to breast cancer induced by DMBA. Intestinal and breast microbiota analysis showed that VDR deficiency leads to a bacterial profile shift from normal to susceptible to carcinogenesis. We found enhanced bacterial staining within breast tumors. At the molecular and cellular levels, we identified the mechanisms by which intestinal epithelial VDR deficiency led to increased gut permeability, disrupted tight junctions, microbial translocation, and enhanced inflammation, thus increasing tumor size and number in the breast. Furthermore, treatment with the beneficial bacterial metabolite butyrate or the probiotic Lactobacillus plantarum reduced breast tumors, enhanced tight junctions, inhibited inflammation, increased butyryl-CoA transferase, and decreased levels of breast Streptococcus bacteria in VDRΔIEC mice. The gut microbiome contributes to the pathogenesis of diseases not only in the intestine but also in the breast. Our study provides insights into the mechanism by which intestinal VDR dysfunction and gut dysbiosis lead to a high risk of extraintestinal tumorigenesis. Gut-tumor-microbiome interactions represent a new target in the prevention and treatment of breast cancer.

Bone Metastases of Diverse Primary Origin Frequently Express the VDR (Vitamin D Receptor) and CYP24A1

Active vitamin D (1,25(OH)2D3) is known to exert direct anti-cancer actions on various malignant tissues through binding to the vitamin D receptor (VDR). These effects have been demonstrated in breast, prostate, renal and thyroid cancers, which all have a high propensity to metastasise to bone. In addition, there is evidence that vitamin D catabolism via 24-hydroxylase (CYP24A1) is altered in tumour cells, thus, reducing local active vitamin D levels in cancer cells. The aim of this study was to assess VDR and CYP24A1 expression in various types of bone metastases by using immunohistochemistry. Overall, a high total VDR protein expression was detected in 59% of cases (39/66). There was a non-significant trend of high-grade tumours towards the low nuclear VDR expression (p = 0.07). Notably, patients with further distant metastases had a reduced nuclear VDR expression (p = 0.03). Furthermore, a high CYP24A1 expression was detected in 59% (39/66) of bone metastases. There was a significant positive correlation between nuclear VDR and CYP24A1 expression (p = 0.001). Collectively, the VDR and CYP24A1 were widely expressed in a multitude of bone metastases, pointing to a potential role of vitamin D signalling in cancer progression. This is of high clinical relevance, as vitamin D deficiency is frequent in patients with bone metastases.

Vitamin D receptor (VDR) mRNA overexpression is associated with poor prognosis in breast carcinoma

Purpose

The prognostic value of vitamin D receptor gene (VDR) expression in breast cancer development is unclear. Here, we aimed to investigate whether VDR expression can be used as a prognostic indicator of breast cancer.

Methods

We used various public bioinformatics platforms: Oncomine, GEPIA, UALCAN, Kaplan-Meier plotter, UCSC XENA, bc-GenExMiner, WebGestalt, and STRING database.

Results

We found that VDR was upregulated in breast cancer in comparison to normal tissues. Overexpression of VDR was significantly associated with worse overall survival in breast cancer. The expression of VDR was related to age, TNM stages, estrogen receptor status, progesterone receptor status, human epidermal growth factor receptor 2 status, basal-like (PAM 50) status, triple-negative breast cancer (TNBC) status, and basal-like (PAM 50) & TNBC status (P < 0.05). Increased VDR expression in breast cancer was significantly associated with older age. The 5 hub genes for VDR were NCOA1, EP300, CREBBP, and RXRA.

Conclusion

Our investigation offers hints about the prognostic role of VDR in breast cancer. The findings suggest that VDR expression might be used as a marker to determine a breast cancer patient's prognosis. Nevertheless, further validation is warranted.

Levels of Vitamin D and Expression of the Vitamin D Receptor in Relation to Breast Cancer Risk and Survival

Previous research suggests associations between low systemic levels of vitamin D and poor breast cancer prognosis and between expression of the vitamin D receptor (VDR) in breast cancers and survival. This study aimed to study associations between pre-diagnostic systemic levels of vitamin D and expression of VDR in subsequent breast tumors, and interactions between vitamin D and VDR on breast cancer mortality. Systemic vitamin D levels were measured in women within the Malmö Diet and Cancer Study. The expression of VDR was evaluated immunohistochemically in a tissue microarray of subsequent breast cancers. Statistical analyses followed. Women with high levels of vitamin D had a smaller proportion of VDR negative breast tumors compared to women with low levels of vitamin D (odds ratio: 0.68; 95% confidence interval: 0.41–1.13). Vitamin D levels were not found to modify the association between low VDR expression and high breast cancer mortality. To conclude, there was no statistical evidence for an association between pre-diagnostic levels of vitamin D and the expression of VDRs in breast cancer, nor did vitamin D levels influence the association between VDR expression and breast cancer mortality. Further studies are needed in order to establish the effects of vitamin D on breast cancer.

Vitamin D, Th17 Lymphocytes, and Breast Cancer

Simple Summary

The effect of vitamin D₃ on the development of breast cancer (favorable, ineffective, or even unfavorable) depends on many factors, such as age, menopausal status, or obesity. The immunomodulatory effect of vitamin D may be unfavorable in case of breast cancer progression. The effect of vitamin D on Th17 cells may depend on disease type and patients’ age. Our goal was to summarize the data available and to find indications of vitamin D treatment failure or success. Therefore, in this review, we present data describing the effects of vitamin D₃ on Th17 cells, mainly in breast cancer.

Abstract

Vitamin D₃, which is well known to maintain calcium homeostasis, plays an important role in various cellular processes. It regulates the proliferation and differentiation of several normal cells, including immune and neoplastic cells, influences the cell cycle, and stimulates cell maturation and apoptosis through a mechanism dependent on the vitamin D receptor. The involvement of vitamin D₃ in breast cancer development has been observed in numerous clinical studies. However, not all studies support the protective effect of vitamin D₃ against the development of this condition. Furthermore, animal studies have revealed that calcitriol or its analogs may stimulate tumor growth or metastasis in some breast cancer models. It has been postulated that the effect of vitamin D₃ on T helper (Th) 17 lymphocytes is one of the mechanisms promoting metastasis in these murine models. Herein we present a literature review on the existing data according to the interplay between vitamin D, Th17 cell and breast cancer. We also discuss the effects of this vitamin on Th17 lymphocytes in various disease entities known to date, due to the scarcity of scientific data on Th17 lymphocytes and breast cancer. The presented data indicate that the effect of vitamin D₃ on breast cancer development depends on many factors, such as age, menopausal status, or obesity. According to that, more extensive clinical trials and studies are needed to assess the importance of vitamin D in breast cancer, especially when no correlations seem to be obvious.

Cholesterol and Its Derivatives: Multifaceted Players in Breast Cancer Progression

Cholesterol is an essential lipid primarily synthesized in the liver through the mevalonate pathway. Besides being a precursor of steroid hormones, bile acid, and vitamin D, it is an essential structural component of cell membranes, is enriched in membrane lipid rafts, and plays a key role in intracellular signal transduction. The lipid homeostasis is finely regulated end appears to be impaired in several types of tumors, including breast cancer. In this review, we will analyse the multifaceted roles of cholesterol and its derivatives in breast cancer progression. As an example of the bivalent role of cholesterol in the cell membrane of cancer cells, on the one hand, it reduces membrane fluidity, which has been associated with a more aggressive tumor phenotype in terms of cell motility and migration, leading to metastasis formation. On the other hand, it makes the membrane less permeable to small water-soluble molecules that would otherwise freely cross, resulting in a loss of chemotherapeutics permeability. Regarding cholesterol derivatives, a lower vitamin D is associated with an increased risk of breast cancer, while steroid hormones, coupled with the overexpression of their receptors, play a crucial role in breast cancer progression. Despite the role of cholesterol and derivatives molecules in breast cancer development is still controversial, the use of cholesterol targeting drugs like statins and zoledronic acid appears as a challenging promising tool for breast cancer treatment.

Cholecalciferol induces apoptosis via autocrine metabolism in epidermoid cervical cancer cells

The anti-cancer effects of vitamin D are of fundamental interest. Cholecalciferol is sequentially hydroxylated endogenously to calcidiol and calcitriol. Here, SiHa epidermoid cervical cancer cells were treated with cholecalciferol (10 - 2600 nM). Cell count and viability were assayed using crystal violet and trypan blue, respectively. Apoptosis was assessed using flow cytometry for early and late biomarkers along with brightfield microscopy and transmission electron microscopy. Autocrine vitamin D metabolism was analysed by qPCR and immunoblotting for activating enzymes; 25-hydroxylases (CYP2R1 and CYP27A1) and 1α-hydroxylase (CYP27B1); the catabolic 24-hydroxylase (CYP24A1); and the vitamin D receptor (VDR). Data were analysed using one-way ANOVA and Bonferroni post hoc test, and p<0.05 was considered significant. After cholecalciferol, cell count (p=0.011) and viability (p<0.0001) decreased, apoptotic biomarkers were positive, mitochondrial membrane potential decreased (p=0.0145), and phosphatidylserine externalisation (p=0.0439); terminal caspase activity (p=0.0025) and nuclear damage (p=0.004) increased. Microscopy showed classical features of apoptosis. Gene and protein expression were concordant. Immunoblots revealed increased CYP2R1 (p = 0.021), VDR (p=0.04) and CYP24A1 (p=0.0274) and decreased CYP27B1 (p=0.031). We conclude that autocrine activation of cholecalciferol to calcidiol may mediate VDR signalling of growth inhibition and apoptosis in SiHa cells.

Vitamin D Deficiency in Women with Breast Cancer: A Correlation with Osteoporosis? A Machine Learning Approach with Multiple Factor Analysis

Breast cancer (BC) is the most frequent malignant tumor in women in Europe and North America, and the use of aromatase inhibitors (AIs) is recommended in women affected by estrogen receptor-positive BCs. AIs, by inhibiting the enzyme that converts androgens into estrogen, cause a decrement in bone mineral density (BMD), with a consequent increased risk of fragility fractures. This study aimed to evaluate the role of vitamin D3 deficiency in women with breast cancer and its correlation with osteoporosis and BMD modifications. This observational cross-sectional study collected the following data regarding bone health: osteoporosis and osteopenia diagnosis, lumbar spine (LS) and femoral neck bone mineral density (BMD), serum levels of 25-hydroxyvitamin D3 (25(OH)D3), calcium and parathyroid hormone. The study included 54 women with BC, mean age 67.3 ± 8.16 years. Given a significantly low correlation with the LS BMD value (r2 = 0.30, p = 0.025), we assessed the role of vitamin D3 via multiple factor analysis and found that BMD and vitamin D3 contributed to the arrangement of clusters, reported as vectors, providing similar trajectories of influence to the construction of the machine learning model. Thus, in a cohort of women with BC undergoing Ais, we identified a very low prevalence (5.6%) of patients with adequate bone health and a normal vitamin D3 status. According to our cluster model, we may conclude that the assessment and management of bone health and vitamin D3 status are crucial in BC survivors.

The Association of Intra-Tumoral and Stromal Vitamin D Receptor (VDR) Expressions with Molecular Subtypes and Clinicopathological Factors in Breast Carcinoma

OBJECTIVE

This study aimed to investigate the association between intra-tumoral and stromal VDR expressions with molecular subtypes and clinicopathological factors.

METHODS

A total of 75 formalin-fixed paraffin embedded tissue samples were stained using immunohistochemical methods. The VDR expressions were measured by counting brown-stained nuclei in intra-tumoral and stromal areas. The association of VDR expression with molecular subtypes and clinopathological factors was examined. Statistical analysis was performed by chi square tests.

RESULTS

High intra-tumoral VDR expression was found in carcinomas with luminal molecular subtypes (p=0.039) and low histological degrees (p=0.035). High VDR expression in the stroma was found in breast carcinomas with large tumor sizes.

CONCLUSIONS

High intra-tumoral VDR expression is found in breast carcinomas with luminal subtypes and low histological grade (I/II). Both factors are known to have a good prognosis. These findings further strengthen the function of VDR as anti-tumorigenesis.

The ERRα-VDR axis promotes calcitriol degradation and estrogen signaling in breast cancer cells, while VDR-CYP24A1-ERRα overexpression correlates with poor prognosis in patients with basal-like breast cancer

Vitamin D is used to reduce cancer risk and improve the outcome of cancer patients, but the vitamin D receptor (VDR; also known as the calcitriol receptor) pathway needs to be functionally intact to ensure the biological effects of circulating calcitriol, the active form of vitamin D. Besides estrogen receptor alpha (ERα), estrogen-related receptor alpha (ERRα) has also been shown to interfere with the VDR pathway, but its role in the antitumor and transactivation activity of calcitriol is completely unknown in breast cancer (BC). We observed that ERRα functionally supported the proliferation of BC cell lines and acted as a calcitriol-induced regulator of VDR. As such, ERRα deregulated the calcitriol-VDR transcription by enhancing the expression of CYP24A1 as well as of both ERα and aromatase (CYP19A1) in calcitriol-treated cells. ERRα knockdown limited the effect of calcitriol by reducing calcitriol-induced G0/G1 phase cell cycle arrest and by affecting the expression of cyclin D1 and p21/Waf. The interactome analysis suggested that Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-α (PGC-1α) and Proline-, glutamic acid-, and leucine-rich protein 1 (PELP1) are key players in the genomic actions of the calcitriol-VDR-ERRα axis. Evaluation of patient outcomes in The Cancer Genome Atlas (TCGA) dataset showed the translational significance of the biological effects of the VDR-ERRα axis, highlighting that VDR, CYP24A1, and ERRα overexpression correlates with poor prognosis in basal-like BC.

Vitamin D Receptor Expression and its Clinical Significance in Papillary Thyroid Cancer

Objective: This study aimed to evaluate the association between vitamin D receptor (an essential component in the vitamin D signaling pathway) and serum vitamin D as well as its clinical significance in papillary thyroid cancer. Methods: This prospective cohort study comprised patients with thyroid tumors who visited our hospital, from 2017 to 2018. The level of vitamin D receptor expression from thyroid tissue was measured in patients with thyroid tumor and evaluated for correlation with serum vitamin D levels and clinicopathologic characteristics of papillary thyroid cancer. Data from 501 patients with papillary thyroid cancer from The Cancer Genome Atlas database were analyzed. Results: Increased vitamin D receptor protein and mRNA expression were observed in papillary thyroid cancer compared to those in normal and benign tissues. Lower vitamin D receptor protein expression was associated with high TNM stage papillary thyroid cancer and low p21 protein expression. Lower relative vitamin D receptor mRNA expression in papillary thyroid cancer was associated with low serum 25-hydroxyvitamin D level. The Cancer Genome Atlas database showed a positive correlation among mRNA expression of vitamin D receptor, CYP24A1, and p21. Conclusions: An association between decreased vitamin D receptor protein expression and advanced stage papillary thyroid cancer, and a correlation between low vitamin D receptor mRNA expression with low serum 25-hydroxyvitamin D level was observed. Low vitamin D receptor expression in papillary thyroid cancer was shown to positively correlate with low serum vitamin D level and disease aggressiveness.

The Role of the Vitamin D Receptor in the Pathogenesis, Prognosis, and Treatment of Cutaneous Melanoma

Melanoma is the malignant transformation of melanocytes and represents the most lethal form of skin cancer. While early-stage melanoma localized to the skin can be cured with surgical excision, metastatic melanoma often requires a multi-pronged approach and even then can exhibit treatment resistance. Understanding the molecular mechanisms involved in the pathogenesis of melanoma could lead to novel diagnostic, prognostic, and therapeutic strategies to ultimately decrease morbidity and mortality. One emerging candidate that may have value as both a prognostic marker and in a therapeutic context is the vitamin D receptor (VDR). VDR is a nuclear steroid hormone receptor activated by 1,25 dihydroxy-vitamin D3 [calcitriol, 1,25(OH)₂D3]. While 1,25 dihydroxy-vitamin D3 is typically thought of in relation to calcium metabolism, it also plays an important role in cell proliferation, differentiation, programmed-cell death as well as photoprotection. This review discusses the role of VDR in the crosstalk between keratinocytes and melanocytes during melanomagenesis and summarizes the clinical data regarding VDR polymorphisms, VDR as a prognostic marker, and potential uses of vitamin D and its analogs as an adjuvant treatment for melanoma.

Vitamin D as a Potential Preventive Agent For Young Women's Breast Cancer

Clinical studies backed by research in animal models suggest that vitamin D may protect against the development of breast cancer, implicating vitamin D as a promising candidate for breast cancer prevention. However, despite clear preclinical evidence showing protective roles for vitamin D, broadly targeted clinical trials of vitamin D supplementation have yielded conflicting findings, highlighting the complexity of translating preclinical data to efficacy in humans. While vitamin D supplementation targeted to high-risk populations is a strategy anticipated to increase prevention efficacy, a complimentary approach is to target transient, developmental windows of elevated breast cancer risk. Postpartum mammary gland involution represents a developmental window of increased breast cancer promotion that may be poised for vitamin D supplementation. Targeting the window of involution with short-term vitamin D intervention may offer a simple, cost-effective approach for the prevention of breast cancers that develop postpartum. In this review, we highlight epidemiologic and preclinical studies linking vitamin D deficiency with breast cancer development. We discuss the underlying mechanisms through which vitamin D deficiency contributes to cancer development, with an emphasis on the anti-inflammatory activity of vitamin D. We also discuss current evidence for vitamin D as an immunotherapeutic agent and the potential for vitamin D as a preventative strategy for young woman's breast cancer.

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 D receptor (VDR) expression in different molecular subtypes of canine mammary carcinoma

BACKGROUND

The molecular-based classification of canine mammary carcinomas (CMCs) has been the focus of much current research. Both in canines and humans, the triple-negative (TN) molecular subtype of mammary cancer is defined by a lack of expression of progesterone receptor (PR), oestrogen receptor (ER) and HER2. It has a poor prognosis; no effective targeted therapy is available. Vitamin D displays anticarcinogenic properties, and the expression of its receptor (VDR) has been found in different molecular subtypes, being about 30-40 % of TN breast cancer (TNBC) positive to it. We assessed the VDR expression in the different molecular subtypes of 58 CMCs from 45 female dogs using an immunohistochemical panel for the molecular classification of included: PR, ER, HER2, cytokeratin (CK) 5, CK14, and Ki67. In addition, we studied the relationship among the molecular subtypes of CMCs and clinicopathologic parameters.

RESULTS

Investigation showed VDR positivity in 45.0 % of the triple-negative CMCs (TNCMCs), 27.3 % of luminal B and 19.0 % of luminal A. Luminal A was the most molecular subtype represented of the total tumours (36.2 %), followed of TNCMCs (34.5 %), luminal B (20.7 %) and HER2-overexpression (10.3 %). Both HER2-overexpression and TNCMC subtypes were positively related to lymphatic invasion (P = 0.028), simple histologic subtype (P = 0.007), a higher histological grade (P = 0.045) and a trend to higher proliferation index (P = 0.09).

CONCLUSIONS

The highest VDR expression was observed in TNCMC, being almost half of them (45 %) positive to this receptor. VDR expression was absent in HER2-overexpression tumours and low in luminal A and B molecular subtypes.

The Clinical Value of VDR and CTLA 4 in Evaluating the Prognosis of Invasive Duct Carcinoma of Egyptian Patients and their Benefit as a Target Therapy

OBJECTIVE

Breast cancer represents the second most common female malignancies worldwide  and  the most common in Egypt. The nuclear vitamin D receptor plays a role in the biology of cancer by affecting inflammatory microenvironment. The aim of this study is to evaluate the role of VDR and CTLA 4 in invasive duct carcinoma of Egyptian patients.

METHODS

This is a retrospective study that included 70 invasive duct carcinoma specimens retrieved from the archival material of Pathology Department, Faculty of medicine, Menoufia University, Egypt, spanning the period between January 2010 and December 2017. All cases were stained for VDR and CTLA 4 antibodies.

RESULTS

There is significant association between high VDR expression in tumor cells and parameters of good prognosis as low tumor stage (T1) and (N0) stage. On the other hand, there is significant association between low CTLA4 tumor expression and good prognostic parameters as low tumor stage (T1) and absent vascular invasion. Regarding lymphocyte expression, there is significant association between positive CTLA4 expression in lymphocytes and parameters of good prognosis as absent metastasis. High VDR tumor expression is the most independent prognostic factor on overall survival of breast carcinoma patients.

CONCLUSION

high VDR expression in tumor cells is associated with good prognostic parameters and is the most independent prognostic factor on overall survival  so it might be of benefit as a target therapy for Egyptian invasive duct carcinoma patients and VDR might augment the expression of CTLA-4, So tailored  immunotherapy might have an impact on invasive duct carcinoma patients.<br />.

Vitamin D analogues exhibit antineoplastic activity in breast cancer patient-derived xenograft cells

Despite advances in breast cancer (BC) treatment, its mortality remains high due to intrinsic or acquired resistance to therapy. Several ongoing efforts are being made to develop novel drugs to treat this pathology with the aim to overcome resistance, prolong patient survival and improve their quality of life. We have previously shown that the non-hypercalcemic vitamin D analogues EM1 and UVB1 display antitumor effects in preclinical studies employing conventional cell lines and animal models developed from these cells. In this work, we explored the antitumor effects of EM1 and UVB1 employing BC cells derived from patient-derived xenografts (PDXs), which are a powerful preclinical tool for testing new drugs. We demonstrated that the analogues reduced the viability of HER2-positive and Triple Negative BC-PDXs. Moreover, using an in vitro model of acquired resistance to Trastuzumab-emtansine, UVB1 displayed anti-proliferative actions under 2D and 3D culture conditions. It inhibited both formation and growth of established organoids. In addition, a direct correlation between UVB1 antitumor effects and VDR expression in PDXs was found. In conclusion, all the results reinforce the potential use of these vitamin D analogues as antitumor agents to treat HER2-positive and Triple Negative BC.

Influence of Stress on the Vitamin D-Vitamin D Receptor System, Macrophages, and the Local Inflammatory Milieu in Endometriosis

We previously demonstrated the negative impact of stress in an animal model of endometriosis. Although its role is unclear, altered levels of vitamin D (VitD) have been found in patients with this condition. VitD signaling through the VitD receptor (VDR) has anti-proliferative properties and induces an anti-inflammatory phenotype in macrophages. We hypothesized that stress impacts the vitamin D-VDR system, influencing macrophage behavior and the local inflammatory milieu in endometriosis. Endometriosis was surgically induced in female Sprague-Dawley rats, which were then exposed to uncontrollable, controllable, or no stress for 10 days. Sham controls received sutures only. VitD levels were measured by ELISA; cytokine levels by multiplex assay and PCR; and VDR expression and macrophage numbers assessed by immunohistochemistry and immunofluorescence. VDR expression in patient samples was assessed by immunohistochemical staining of a tissue microarray. Serum VitD levels were higher in endometriosis animals compared with sham (p < 0.01) with no significant effect of stress. Uncontrollable stress increased macrophage infiltration (p < 0.01) and VDR expression in vesicles, which were attenuated by controllable stress. Macrophage infiltration correlated with vesicle area (p < 0.05), and peritoneal vitamin D levels correlated with vesicle VDR expression (r = 0.81, p < 0.01). Decreased expression of chemokine ligand 2 (p < 0.05) and TGFβ was observed in endometriosis with uncontrollable stress, whereas IL12 increased with controllable stress. Differential expression of VDR was observed in patient tissues. Stress exacerbates development of cysts in endometriosis through mechanisms that include macrophage recruitment, cytokine changes, and a potentially perturbed VitD:VDR axis, suggesting an impact on the local inflammatory environment.

Vitamin D receptor (VDR) and metabolizing enzymes CYP27B1 and CYP24A1 in breast cancer

Vitamin D Receptor (VDR), a nuclear steroid receptor, is a transcription factor with a primary physiologic role in calcium metabolism. It has also a physiologic role in breast tissues during development of the gland and postpartum. In addition, it is commonly expressed in breast cancer and has tumor suppressive effects. Cytochrome enzymes CYP27B1 and CYP24A1 that perform the final conversion of the circulating form of vitamin D, 25-hydroxyvitamin D (25-OHD) to the active VDR ligand, 1a,25-dihydroxyvitamin D and the catabolism of it to inactive 24,25-dihydroxyvitamin D, respectively, are also expressed in breast cancer tissues. Defective regulation of the receptor and the metabolic enzymes of VDR ligand is prevalent in breast cancer and leads to decreased VDR signaling. The expression and molecular defects of VDR, CYP27B1 and CYP24A1 that perturb physiologic function, the implications for breast cancer progression and therapeutic opportunities are discussed in this paper.

Vitamin D Metabolite Profile in Cholecalciferol- or Calcitriol-Supplemented Healthy and Mammary Gland Tumor-Bearing Mice

To analyze if the prometastatic activity of calcitriol (active vitamin D₃ metabolite), which was previously observed in a 4T1 breast cancer model, is also found in other breast cancers, and to assess the impact of various schemes of vitamin D supply, we used 4T1 and E0771 mouse metastatic and 67NR nonmetastatic cells in this study. BALB/c and C57BL/6 healthy and tumor-bearing mice were exposed to a control (1000 IU), low- (100 IU), and high- (5000 IU) vitamin D₃ diets. Additionally, from day 7 of tumor transplantation, the 1000 and 100 IU groups were gavaged with calcitriol (+cal). After 8 weeks of feeding, plasma levels of 25(OH)D₃, 24,25(OH)₂D₃, and 3-epi-25(OH)D₃ were significantly lower in calcitriol-treated and vitamin D-deficient groups than in the control, whereas the levels of all metabolites were increased in the 5000 IU group. The ratio of 25(OH)D₃:24,25(OH)₂D₃ was increased in both calcitriol-treated groups, whereas the ratio of 25(OH)D₃:3-epi-25(OH)D₃ was increased only in the 100 IU group but decreased in the 5000 IU group. In contrast to E0771, 4T1 lung metastasis was accelerated in all vitamin D-supplemented mice, as well as in the deficient group with an increased inflammatory response. 67NR tumor growth was transiently inhibited in the 1000 IU+cal group, but single metastases were observed in the 5000 and 100 IU groups. Based on the results, we conclude that various schemes of vitamin D supply and vitamin D deficiency led to similar metabolite profiles irrespective of the mice strain and tumor burden. However, depending on the type of breast cancer, different effects on tumor growth and metastasis were noticed.

Prognostic role of vitamin D receptor in breast cancer: a systematic review and meta-analysis

Background

A higher vitamin D intake improves the prognosis of early stage breast cancer (BC) patients. We hypothesized that vitamin D intake should refer to vitamin D receptor (VDR) expression. In order to prove this hypothesis, we first intend to evaluate the correlation between VDR expression and prognosis of BC patients using meta-analysis.

Methods

Literatures from PubMed, Embase, and the Cochrane Library (last update by May 20, 2020) were retrieved to find studies assessing the prognostic role of VDR in BC. The hazard ratios (HRs) for patients’ survival were extracted for pooled analyses. Subgroup analysis, sensitivity analysis and meta-regression were performed to explore the sources of heterogeneity.

Results

Seven articles containing eight studies with 2503 patients were enrolled. The results from the pooled analyses showed that the VDR expression generally had no relationship with BC patients’ overall survival (OS), disease-free survival (DFS), cancer-specific survival (CSS), and progression-free survival (PFS) (P > 0.05). Because only the number of studies exploring the relationship between VDR expression and OS is greater than five and there is heterogeneity, we explored the sources of heterogeneity of these studies. Subgroup analyses showed that the VDR expression in the nucleus had no relationship with OS, but high total VDR expression in the nucleus and cytoplasm was related to a better OS (pooled HR = 0.41; 95% CI = 0.18–0.95; P = 0.038). In addition, in subgroup of studies using cut-off values other than ‘immunoreactive score (IRS)>5’ and ‘IRS > 25′, high VDR expression was associated with a better OS (pooled HR = 0.47; 95% CI = 0.30–0.74; P = 0.001). Sensitivity analysis showed that the result pattern was not obviously affected by any single study. Meta-regression showed that the source of heterogeneity was not country (P = 0.657), pathological type (P = 0.614), molecular type (P = 0.423), staining location (P = 0.481), or cut-off value (P = 0.509).

Conclusions

The protein expression level of VDR in entire BC cells evaluated by immunohistochemistry is related to the OS of BC patients. It is expected that a more individualized vitamin D intake and a more accurate prognosis assessment can be recommended for BC patients based on the VDR expression. Of course, more preclinical and clinical studies are needed.

Incidence and Clinicopathological Features of Breast Cancer in the Northern Emirates: Experience from Sharjah Breast Care Center

BACKGROUND

Breast cancer is the most frequently reported cancer among women in the Middle East and North Africa (MENA) region. However, the available data about women breast cancer from the MENA and particularly from the Northern Emirates region of the United Arab Emirates (UAE) are scarce and inconsistent. Therefore, this study estimated the incidence, patient-specific factors including 25(OH)D levels, and clinicopathological features of breast cancer in women from the Northern Emirates.

METHODS

We conducted this retrospective case-control study on 1,048 women who were referred to the Sharjah Breast Care Centre at University Hospital Sharjah between March 2016 and July 2018. Multivariate logistic regression was used for the statistical analysis of clinical data.

RESULTS

Out of 1048 women with breast-related conditions referred to our canter, 94 (10%) were diagnosed with breast cancer (1 in 11), and approximately 1 in 5 of these women was younger than 40 years. After adjusting for age, body mass index and menopause status, women with serum 25-hydroxyvitamin D [25(OH)D] levels lower than 20 ng/mL were found to be at higher risk of breast cancer (odd ratio, 4.63; 95% CI, 2.61-8.23). The majority of breast cancer cases had invasive-ductal carcinoma with hormone-positive receptor molecular subtype (78 cases out of 94, 83%). HER2 overexpressing tumor (3+ by immunohistochemistry (IHC) or by fluorescence in situ hybridization (FISH)) was seen more in women younger than 40 years as compared to older women (7 cases out of 19 HER2 expressed tumors, p=0.007).

CONCLUSION

Our study cohort showed a mean age of diagnosis of breast cancer in women a decade earlier than in the developed countries. Furthermore, women with breast cancer tend to be serum 25(OH)D deficient at diagnosis and to have luminal A tumors.

Vitamin D Effects on Cell Differentiation and Stemness in Cancer

Vitamin D₃ is the precursor of 1α,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃), a pleiotropic hormone that is a major regulator of the human genome. 1,25(OH)₂D₃ modulates the phenotype and physiology of many cell types by controlling the expression of hundreds of genes in a tissue- and cell-specific fashion. Vitamin D deficiency is common among cancer patients and numerous studies have reported that 1,25(OH)₂D₃ promotes the differentiation of a wide panel of cultured carcinoma cells, frequently associated with a reduction in cell proliferation and survival. A major mechanism of this action is inhibition of the epithelial–mesenchymal transition, which in turn is largely based on antagonism of the Wnt/β-catenin, TGF-β and EGF signaling pathways. In addition, 1,25(OH)₂D₃ controls the gene expression profile and phenotype of cancer-associated fibroblasts (CAFs), which are important players in the tumorigenic process. Moreover, recent data suggest a regulatory role of 1,25(OH)₂D₃ in the biology of normal and cancer stem cells (CSCs). Here, we revise the current knowledge of the molecular and genetic basis of the regulation by 1,25(OH)₂D₃ of the differentiation and stemness of human carcinoma cells, CAFs and CSCs. These effects support a homeostatic non-cytotoxic anticancer action of 1,25(OH)₂D₃ based on reprogramming of the phenotype of several cell types.

Immunohistochemical expression of vitamin D receptor and forkhead box P3 in classic Hodgkin lymphoma: correlation with clinical and pathologic findings

Background

Expression of forkhead box P3 (FOXP3), a key regulator of T-cell function, in the tumor immune microenvironment is related to survival in classic Hodgkin lymphoma (CHL). Vitamin D receptor (VDR), a transcription factor agonists have been shown to induce FOXP3 expression in T-cells and enhance recruitment of these cells to the inflammatory sites. VDR expression is CHL has been described. However, there is no data on expression of VDR in context of quantity of FOXP3 positive cells in CHL.

Methods

We examined and correlated immunohistochemical expression of VDR and FOXP3 along with clinical and pathology findings in 29 cases of CHL.

Results

VDR was expressed in Hodgkin Reed-Sternberg (HRS) cells and background lymphocytes and FOXP3 was expressed in background lymphocytes. 82% of CHL cases, regardless of the subtype, expressed VDR and in majority of the cases, VDR expression was directly proportional to the quantity of FOXP3 expressing lymphocytes in the tumor microenvironment. In cases with higher clinical stage (III/IV), only 28.5% of cases diffusely expressed VDR and FOXP3 compared to 71.4% showing focal positivity. Whereas in cases with lower clinical stages (I/II), the expression pattern of VDR and FOXP3 was almost similar (41.6% diffuse versus 33.3% focal). Interestingly, focal VDR and FOXP3 expression pattern was significantly higher among males. Mixed cellularity cases showed predilection for focal VDR and FOXP3 expression (80% cases); whereas nodular sclerosis subtype had focal and diffuse VDR and FOXP3 expression patterns in similar proportion. Cases with diffuse VDR and FOXP3 expression were less likely to have bone marrow involvement. Epstein Barr virus- encoded small RNA (EBER) positive cases were predominantly focally positive (80%) for VDR and FOXP3.

Conclusions

In summary, quantity of FOXP3 positive T-cells in CHL microenvironment seems to correlate with VDR expression. Clinical stage show a trend of inverse correlation with expression of VDR and quantity of FOXP3 positive T-cells. These findings suggest that VDR could be a possible prognostic and therapeutic target in CHL.

Vitamin D and Cancer Survival: Does Vitamin D Supplementation Improve the Survival of Patients with Cancer?

PURPOSE OF REVIEW

Clinical evidence suggesting the beneficial effects of vitamin D on survival of patients with cancer has been accumulating. Recent articles were thoroughly reviewed to determine if there is enough evidence to conclude that vitamin D supplementation improves survival of patients with cancer.

RECENT FINDINGS

Meta-analyses of observational studies showed that higher blood 25-hydroxyvitamin D levels in patients with cancer at a variety of sites were associated with lower cancer-specific and overall mortalities. Moreover, meta-analyses of randomized clinical trials (RCTs) also suggested that vitamin D supplementation improved the survival of patients with cancer. However, each RCT used in these meta-analyses, as well as very recent RCTs, e.g., the SUNSHINE and the AMATERASU trial, did not show statistical significance in the primary results. For now, compelling evidence that vitamin D supplementation effectively improves survival of patients with cancer is lacking. Thus, confirmatory RCTs are still obligatory for the future.

Vitamin D in Triple-Negative and BRCA1-Deficient Breast Cancer-Implications for Pathogenesis and Therapy

Several studies show that triple-negative breast cancer (TNBC) patients have the lowest vitamin D concentration among all breast cancer types, suggesting that this vitamin may induce a protective effect against TNBC. This effect of the active metabolite of vitamin D, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D), can be attributed to its potential to modulate proliferation, differentiation, apoptosis, inflammation, angiogenesis, invasion and metastasis and is supported by many in vitro and animal studies, but its exact mechanism is poorly known. In a fraction of TNBCs that harbor mutations that cause the loss of function of the DNA repair-associated breast cancer type 1 susceptibility (BRCA1) gene, 1,25(OH)2D may induce protective effects by activating its receptor and inactivating cathepsin L-mediated degradation of tumor protein P53 binding protein 1 (TP53BP1), preventing deficiency in DNA double-strand break repair and contributing to genome stability. Similar effects can be induced by the interaction of 1,25(OH)2D with proteins of the growth arrest and DNA damage-inducible 45 (GADD45) family. Further studies on TNBC cell lines with exact molecular characteristics and clinical trials with well-defined cases are needed to determine the mechanism of action of vitamin D in TNBC to assess its preventive and therapeutic potential.

Divergent Effect of Tacalcitol (PRI-2191) on Th17 Cells in 4T1 Tumor Bearing Young and Old Ovariectomized Mice

Vitamin D and its analogs are known for their role in the development of breast cancer and in immunomodulation. Our previous studies have shown the pro-metastatic effect of calcitriol and tacalcitol (PRI-2191) in young mice bearing 4T1 breast cancer and the anti-metastatic effect in aged ovariectomized (OVX) mice. Therefore, the aim of our work was to characterize Th17 cell population in young and aged OVX mice bearing 4T1 tumors treated with calcitriol and PRI-2191. The expression of genes typical for Th17 cells was examined in splenocytes, as well as splenocytes differentiated with IL-6 and TGF-β to Th17 cells (iTh17). Expression of genes encoding vitamin D receptor (Vdr) and osteopontin (Spp1) as well as the secretion of IL-17A were evaluated in iTh17 cells. PRI-2191 treatment increased the expression of Rora and Rorc transcription factors, Il17a, Il17re and Il21 in iTh17 cells from young mice. In aged OVX mice this effect was not observed. Increased expression was observed in the case of Vdr and Spp1 genes in iTh17 cells from young mice treated with PRI-2191. What is more, in young mice treated with PRI-2191 the secretion of IL-17A to the culture media by iTh17 cells was increased, whereas in aged OVX mice a significant decrease was noted. Increased expression of Spp1 in young mice treated with PRI-2191 may enhance the differentiation of Th17 cells.

Decreased vitamin D receptor protein expression is associated with progression and poor prognosis of colorectal cancer patients

This study aimed to investigate vitamin D receptor (VDR) expression levels and evaluate their clinical significance in patients with colorectal cancer (CRC). VDR protein expression was validated by immunohistochemistry in 188 CRC tissues and 134 normal colorectal tissues. The associations between VDR expression and clinicopathologic characteristics, including prognostic outcomes, were analyzed. VDR expression in normal colorectal tissue was higher than that in CRC (83.6% versus 34.6%, P = 4.489 × 10^-20) and generated moderate diagnostic performance for CRC detection (AUC = 0.88, sensitivity = 0.87, specificity = 0.84). Low VDR expression was associated with invasion depth (P = 0.001) and poor survival in CRC (P = 0.031). Univariate Cox analysis demonstrated VDR expression (P = 0.036) was a significant prognostic predictor for survival in patients with CRC. Low VDR expression could be a valuable diagnostic and prognostic biomarker for CRC patients. Targeting VDR may offer a potential therapeutic strategy for blocking CRC.

Hormone Receptor Expression in Multicentric/Multifocal versus Unifocal Breast Cancer: Especially the VDR Determines the Outcome Related to Focality

The aim of this study was to evaluate the prognostic impact that hormone receptor (HR) expressions have on the two different breast cancer (BC) entities—multifocal versus unifocal BC. As the prognosis determining aspects, we investigated the overall survival (OS) and disease-free survival (DFS) by univariate and multivariate analysis. To underline the study’s conclusions, we additionally considered the histopathological grading and the tumor node metastasis (TNM) staging. A retrospective analysis was performed on survival-related events in a series of 320 breast cancer patients treated at the Department of Gynecology and Obstetrics at the Ludwig Maximillian University in Munich between 2000 and 2002. All three steroid receptors analyzed by immunohistochemistry, namely, the estrogen receptor (ER), the progesterone receptor (PR), and the vitamin D receptor (VDR), showed a significantly positive influence on the course of the disease, but only for the unifocal breast tumor patients. The prognosis of patients with multifocal breast cancer was either not affected by estrogen and/or progesterone receptor expression or even involved a worse etiopathology for the vitamin D receptor-positive patients. The estrogen receptor in unifocal breast cancer and the vitamin D receptor in multifocal breast cancer were especially identified as an independent prognostic marker for overall survival, when adjusted for age, grading, and staging. Altogether, our results strengthen the need to further investigate the behavior of the hormone receptors in breast cancer and understand why they have different effects on each focality type. Moreover, the studies for an adopted vitamin D supplementation due to breast cancer focality type must be enlarged to fully comprehend the remarkable and interesting role played by the vitamin D receptor.

Vitamin D pathway related polymorphisms and vitamin D receptor expression in breast cancer

Vitamin D deficiency is an emerging risk factor for breast cancer suggesting its role in breast cancer pathogenesis. Recent evidence suggests vitamin D receptor (VDR) expression is a prognosis predictor in breast cancer. We set out to determine the status of VDR expression in histologically characterized breast cancers, and whether common genetic variants modify VDR expression in breast cancer. One-hundred and twenty Kuwaiti female breast cancer fixed tissues were assessed for VDR expression to identify the level and location of its expression by immunohistochemistry. VDR variants (rs731236, rs2228570), and vitamin D binding protein (VDBP) variants (rs4588, rs7041) genotypes were ascertained in breast cancer specimens using Taqman genotyping assays. VDR nuclear expression correlated with low grade tumors (p = 0.01), whereas cytoplasmic expression correlated with lymph node positive tumors (p = 0.03). Absence of VDR expression was a marker for high-grade dedifferentiated tumors (p = 0.01). VDBP rs7041 associated with breast cancer risk (OR 1.92, 95% CI: 1.34 - 2.73; p = 0.0004), and VDR rs2228570 correlated with increased VDR cytoplasmic expression (p < 0.0001). In conclusion, VDR expression is altered in breast cancer confirming its involvement in breast cancer progression. Genetic factors appear to play a role in breast cancer risk, and may modify tumor sensitization to vitamin D.

Loss of the Vitamin D Receptor in Human Breast Cancer Cells Promotes Epithelial to Mesenchymal Cell Transition and Skeletal Colonization

Expression of the vitamin D receptor (VDR) is thought to be associated with neoplastic progression. However, the role of the VDR in breast cancer metastasis to bone and the molecular mechanisms underlying this process are unknown. Employing a rodent model (female Balb/c nu/nu mice) of systemic metastasis, we here demonstrate that knockdown of the VDR strongly increases the metastatic potential of MDA-MB-231 human breast cancer cells to bone, resulting in significantly greater skeletal tumor burden. Ablation of VDR expression promotes cancer cell mobility (migration) and invasiveness, thereby facilitating skeletal colonization. Mechanistically, these changes in tumor cell behavior are attributable to shifts in the expression of proteins involved in cell adhesion, proliferation, and cytoskeletal organization, patterns characteristic for epithelial-to-mesenchymal cell transition (EMT). In keeping with these experimental findings, analyses of human breast cancer specimens corroborated the association between VDR expression, EMT-typical changes in protein expression patterns, and clinical prognosis. Loss of the VDR in human breast cancer cells marks a critical point in oncogenesis by inducing EMT, promoting the dissemination of cancer cells, and facilitating the formation of tumor colonies in bone. © 2019 American Society for Bone and Mineral Research.

Vitamin D receptor expression in invasive breast tumors and breast cancer survival

BACKGROUND

Vitamin D has been suggested to prevent and improve the prognosis of several cancers, including breast cancer. We have previously shown a U-shaped association between pre-diagnostic serum levels of vitamin D and risk of breast cancer-related death, with poor survival in patients with the lowest and the highest levels respectively, as compared to the intermediate group. Vitamin D exerts its functions through the vitamin D receptor (VDR), and the aim of the current study was to investigate if the expression of VDR in invasive breast tumors is associated with breast cancer prognosis.

METHODS

VDR expression was evaluated in a tissue microarray of 718 invasive breast tumors. Covariation between VDR expression and established prognostic factors for breast cancer was analyzed, as well as associations between VDR expression and breast cancer mortality.

RESULTS

We found that positive VDR expression in the nuclei and cytoplasm of breast cancer cells was associated with favorable tumor characteristics such as smaller size, lower grade, estrogen receptor positivity and progesterone receptor positivity, and lower expression of Ki67. In addition, both intranuclear and cytoplasmic VDR expression were associated with a low risk of breast cancer mortality, hazard ratios 0.56 (95% CI 0.34-0.91) and 0.59 (0.30-1.16) respectively.

CONCLUSIONS

This study found that high expression of VDR in invasive breast tumors is associated with favorable prognostic factors and a low risk of breast cancer death. Hence, a high VDR expression is a positive prognostic factor.

Vitamin D aggravates breast cancer by inducing immunosuppression in the tumor bearing mouse

The aim of this approach is to test the effects and related mechanism of vitamin D (VD) treatment on the outcomes of breast cancer. BALB/c mice were injected with 4T1 breast cancer cell suspension. The test group was treated with VD reagent. The survival and tumor size of mice were observed. The proliferation of 4T1 in vitro was detected by MTS analysis. The changes of immune parameters and microenvironment in mice were evaluated by flow cytometry and real-time RT-PCR. Our results demonstrate that VD administration caused a decline in survival time and raising the volume of tumor, the decreasing numbers of CD3⁺CD4⁺ T, CD3⁺CD8⁺ T and CD4⁺T-bet⁺IFN-γ⁺ Th1 cells and transcriptions of T-bet and IFN-γ, an increasing number of myeloid-derived suppressor cells and transcription of TGF-β. Our data suggest that the routine clinical application of any strategies targeting VD status for breast cancer therapy is deserved serious consideration.

Genome-wide RNAi Screening Identifies RFC4 as a Factor That Mediates Radioresistance in Colorectal Cancer by Facilitating Nonhomologous End Joining Repair

PURPOSE

Neoadjuvant chemoradiotherapy (neoCRT) is a standard treatment for locally advanced rectal cancer (LARC); however, resistance to chemoradiotherapy is one of the main obstacles to improving treatment outcomes. The goal of this study was to identify factors involved in the radioresistance of colorectal cancer and to clarify the underlying mechanisms.

EXPERIMENTAL DESIGN

A genome-wide RNAi screen was used to search for candidate radioresistance genes. After RFC4 knockdown or overexpression, colorectal cancer cells exposed to X-rays both in vitro and in a mouse model were assayed for DNA damage, cytotoxicity, and apoptosis. Moreover, the regulatory effects and mechanisms of RFC4 in DNA repair were investigated in vitro. Finally, the relationships between RFC4 expression and clinical parameters and outcomes were investigated in 145 patients with LARC receiving neoCRT.

RESULTS

RFC4, NCAPH, SYNE3, LDLRAD2, NHP2, and FICD were identified as potential candidate radioresistance genes. RFC4 protected colorectal cancer cells from X-ray-induced DNA damage and apoptosis in vitro and in vivo. Mechanistically, RFC4 promoted nonhomologous end joining (NHEJ)-mediated DNA repair by interacting with Ku70/Ku80 but did not affect homologous recombination-mediated repair. Higher RFC4 expression in cancer tissue was associated with weaker tumor regression and poorer prognosis in patients with LARC treated with neoCRT, which likely resulted from the effect of RFC4 on radioresistance, not chemoresistance.

CONCLUSIONS

RFC4 was identified as a radioresistance factor that promotes NHEJ-mediated DNA repair in colorectal cancer cells. In addition, the expression level of RFC4 predicted radiotherapy responsiveness and the outcome of neoadjuvant radiotherapy in patients with LARC.

Assessment of functional variants and expression of long noncoding RNAs in vitamin D receptor signaling in breast cancer

Purpose

Vitamin D receptor (VDR) signaling pathway is implicated in the pathogenesis of breast cancer.

Patients and methods

We selected VDR-associated long noncoding RNAs (lncRNAs) through an in silico analysis of available microarray and RNA-sequencing data and assessed their expression in 75 breast tumor samples and their adjacent noncancerous tissues (ANCTs). We also genotyped two functional polymorphisms within VDR gene in all patients.

Results

VDR, MALAT1, and LINC00511 were significantly upregulated in tumoral tissues compared with ANCTs (fold change [FC] =1.85, P=0.03; FC =1.54, P=0.04; and FC =4.75, P=0.000, respectively). In patients younger than 55 years, significant associations were found between expression levels of both SNHG16 and LINC00511 genes and nuclear grade (P=0.03), expression of LINC00346 and tubule formation (P=0.01), expression of both SNHG16 and SNHG6 genes and family history of cancer (P=0.01 and 0.03, respectively), as well as expression of VDR and progesterone receptor status (P=0.03). We detected significant correlations between expression levels of VDR and SNHG16 in both tumoral tissues and ANCTs. The TT genotype of FokI polymorphism was associated with the higher expression levels of VDR. FokI variants were associated with expression levels of both MALAT1 and SNHG16 in ANCTs (P=0.01 and 0.03, respectively). CdxII variants were associated with expression levels of SNHG16 in ANCTs. A significant correlation was found between FC values of SNHG16 expression and vitamin D levels.

Conclusion

The present study provides further evidence for the contribution of VDR signaling and the related lncRNAs in the pathogenesis of breast cancer and introduces some novel lncRNAs as putative molecules in the interactive functional network of VDR signaling in breast cancer.