The potential therapeutic benefits of vitamin D in the treatment of estrogen receptor positive breast cancer

Vitamin D and Its Receptors in Cervical Cancer

Several studies have investigated the relationship between vitamin D (VD) and its receptors (VDR) and the risk of cervical cancer. However, the underlying mechanisms that underpin these associations remain incompletely comprehended. In this review, we analyzed the impacts of VD and VDR on cervical cancer and related mechanisms, and discussed the effects of VD, calcium, and other vitamins on cervical cancer. Our literature research found that VD, VDR and their related signaling pathways played indispensable roles in the occurrence and progression of cervical cancer. Epidemiological studies have established associations between VD, VDR, and cervical cancer susceptibility. Current studies have shown that the inhibitory effect of VD and VDR on cervical cancer may be attributed to a variety of molecules and pathways, such as the EAG potassium channel, HCCR-1, estrogen and its receptor, p53, pRb, TNF-α, the PI3K/Akt pathway, and the Wnt/β-catenin pathway. This review also briefly discussed the association between VDR gene polymorphisms and cervical cancer, albeit a comprehensive elucidation of this relationship remains an ongoing research endeavor. Additionally, the potential ramifications of VD, calcium, and other vitamins on cervical cancer has been elucidated, yet further exploration into the precise mechanistic underpinnings of these potential effects is warranted. Therefore, we suggest that further studies should focus on explorations into the intricate interplay among diverse molecular pathways and entities, elucidation of the mechanistic underpinnings of VDR polymorphic loci changes in the context of HPV infection and VD, inquiries into the mechanisms of VD in conjunction with calcium and other vitamins, as well as investigations of the efficacy of VD supplementation or VDR agonists as part of cervical cancer treatment strategies in the clinical trials.

Estrogen receptor-mediated health benefits of phytochemicals: a review

Estrogen receptors (ERs) are transcription factors with two subtypes: estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), which are essential for the maintenance of human health and play a regulatory role in common diseases such as breast cancer, osteoporosis, neurodegenerative disorders, liver injuries and lung cancers. A number of phytochemicals extracted from various fruits and vegetables have been demonstrated to exhibit estrogenic effects and are termed phytoestrogens. As modulators of ERs, phytoestrogens can be involved in the prevention and treatment of multiple diseases as complementary or alternative therapeutic agents and have a variety of health benefits for humans. This article reviews the health benefits of phytoestrogens in clinical and epidemiologic studies for several diseases and also provides a detailed description of the molecular mechanisms of their action. A brief comparison of the advantages and disadvantages of natural phytochemicals compared to synthetic drugs is also presented. The role of phytoestrogens in the treatment of diseases and human health requires further research to fully realize their therapeutic potential.

Effects of Gender and Vitamin D on Vascular Reactivity of the Carotid Artery on a Testosterone-Induced PCOS Model

The negative cardiovascular effects of polycystic ovary syndrome (PCOS) and vitamin D deficiency (VDD) have been discussed previously; however, the sex differences between PCOS females and males are not yet known. Our aim was to investigate the effect of PCOS and VDD in the carotid artery of male and female Wistar rats. Females were treated with transdermal testosterone (Androgel) for 8 weeks, which caused PCOS. VDD and vitamin D supplementation were accomplished via diet. The carotid arteries' contraction and relaxation were examined using myography. Receptor density was investigated using immunohistochemistry. In PCOS females, angiotensin receptor density, angiotensin II-induced contraction, androgen receptor optical density, and testosterone-induced relaxation increased. The increased contractile response may increase cardiovascular vulnerability in women with PCOS. As an effect of VDD, estrogen receptor density increased in all our groups, which probably compensated for the reduced relaxation caused by VDD. Testosterone-induced relaxation was decreased as a result of VDD in males and non-PCOS females, whereas this reduction was absent in PCOS females. Male sex is associated with increased contraction ability compared with non-PCOS and PCOS females. VDD and Androgel treatment show significant gender differences in their effects on carotid artery reactivity. Both VDD and PCOS result in a dysfunctional vascular response, which can contribute to cardiovascular diseases.

Local production of active vitamin D3 metabolites in breast cancer cells by CYP24A1 and CYP27B1

The role of vitamin D3 and its metabolites in cancer and especially as a treatment option has been widely disputed. Clinicians noting low serum 25-hydroxyvitamin D3 [25(OH)D3] levels in their patients, recommend vitamin D3 supplementation as a method of reducing the risk of cancer; however, data supporting this are inconsistent. These studies rely on systemic 25(OH)D3 as an indicator of hormone status, but 25(OH)D3 is further metabolized in the kidney and other tissues under regulation by several factors. This study examined if breast cancer cells also possess the ability to metabolize 25(OH)D3, and if so, whether the resulting metabolites are secreted locally; if this ability reflects ERα66 status; and if they possess vitamin D receptors (VDR). To address this question, estrogen receptor alpha (ERα) positive (MCF-7) and ERα negative (HCC38 and MDA-MB-231) breast cancer cell lines were examined for expression of ERα66, ERα36, CYP24A1, CYP27B1, and VDR as well as for local production of 24,25-dihydroxyvitamin D3 [24,25(OH)2D3] and 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] after treatment with 25(OH)D3. The results showed that independent of ER status, breast cancer cells express the enzymes CYP24A1 and CYP27B1, which are responsible for converting 25(OH)D3 into its dihydroxylated forms. Moreover, these metabolites are produced at levels comparable to the levels observed in blood. They are positive for VDR, indicating that they can respond to 1α,25(OH)2D3, which can upregulate CYP24A1. These findings suggest that vitamin D metabolites may contribute to the tumorigenicity of breast cancer via autocrine and/or paracrine mechanisms.

Effects of vitamin D supplementation on inflammatory response in patients with cancer and precancerous lesions: Systematic review and meta-analysis of randomized trials

BACKGROUND & AIMS

Inflammation plays a key role in tumor development and progression. Vitamin D has potential tumor suppressing effects through modulation of inflammatory processes. The aim of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to summarize and evaluate the effects of vitamin D3 supplementation (VID3S) on serum inflammatory biomarkers among patients with cancer or pre-cancerous lesions.

METHODS

We searched PubMed, Web of Science and Cochrane databases until November 2022. The effects of VID3S were estimated from pooled standardized mean differences (SMDs) with their 95% confidence intervals (CIs) for inflammatory biomarker follow-up levels between intervention and control groups.

RESULTS

Meta-analysis of eight RCTs (total of 592 patients with cancer or pre-cancerous conditions) showed that VID3S significantly lowered levels of serum tumor necrosis factor (TNF)-α (SMD [95%CI]: -1.65 [-3.07; -0.24]). VID3S also resulted in statistically non-significantly lower serum levels of interleukin (IL)-6 (SMD [95%CI]: -0.83, [-1.78; 0.13]) and C-reactive protein (CRP) (SMD [95%CI]: -0.09, [-0.35; 0.16]), whereas IL-10 levels were unaltered (SMD [95%CI]: -0.00, [-0.50; 0.49]).

CONCLUSION

Our study shows evidence of a significant reduction of TNF-α levels by VID3S for patients with cancer or precancerous lesions. Patients with cancer or precancerous lesions may benefit from personalized VID3S in suppressing tumour-promoting inflammatory response.

PROSPERO REGISTRATION NUMBER

CRD42022295694.

Effect of active vitamin D on proliferation, cell cycle and apoptosis in endometriotic stromal cells

RESEARCH QUESTION

What is the effect of vitamin D3 (1,25(OH)₂D₃) on proliferation, cell cycle and apoptosis of endometrial stromal cells (ESC) in endometriotic patients?

DESIGN

ESC isolated from 10 women with endometriosis and 10 healthy controls were treated with 1,25(OH)₂D₃. The proliferation of control endometrial stromal cells (CESC), eutopic endometrial stromal cells (EuESC) and ectopic endometrial stromal cells (EESC) was analysed 72 h after the treatment using methyl thiazolyl tetrazolium assay. Propidium iodide staining and flow cytometry were used to determine the cell cycle distribution in ESC. Annexin V/propidium iodide double staining was used to evaluate apoptosis in ESC.

RESULTS

In the presence of oestrogen, 1,25(OH)₂D₃ treatment inhibited the proliferation of ESC from all three origins (P = 0.009 for CESC, P = 0.005 for EuESC and P < 0.001 for EESC). The percentage of S phase cells in EESC was higher than in EuESC and CESC (P = 0.002 and P = 0.001, respectively). The percentage of S phase cells in EuESC was higher than in CESC (P = 0.005). The percentage of G1 phase cells in EESC was lower than that of EuESC and CESC (P = 0.003 and P = 0.002, respectively) and the percentage of G1 phase cells in EuESC was lower than that of CESC (P = 0.007). Moreover, 1,25(OH)₂D₃ inhibited cell cycle regardless of cell type (P = 0.002 in EESC, P = 0.001 in EuESC and P = 0.014 in CESC), but in the absence of oestrogen, inhibited cell cycle only in EuESC (P = 0.012).

CONCLUSIONS

Although 1,25(OH)₂D₃ increased apoptotic and necrotic cells and decreased live cells in the EuESC and EESC, it did not affect apoptosis in CESC and only increased necrotic cells. These findings indicate that 1,25(OH)₂D₃ potentially has a growth-inhibiting and pro-apoptotic effect on ESC from endometriotic patients.

Obesity and Breast Cancer: Interaction or Interference with the Response to Therapy?

Background: Aromatase inhibitors (AI) are widely used for treating hormone-sensitive breast cancer (BC). Obesity, however, due to aromatase-mediated androgen conversion into estradiol in the peripheral adipose tissue, might impair AI inhibitory capacity. We aimed at identifying a cut-off of body mass index (BMI) with significant prognostic impact, in a cohort of stage I-II BC patients on systemic adjuvant therapy with AI. Methods: we retrospectively evaluated routinely collected baseline parameters. The optimal BMI cut-off affecting disease-free survival (DFS) in AI-treated BC patients was identified through maximally selected rank statistics; non-linear association between BMI and DFS in the AI cohort was assessed by hazard-ratio-smoothed curve analysis using BMI as continuous variable. The impact of the BMI cut-off on survival outcomes was estimated through Kaplan−Meier plots, with log-rank test and hazard ratio estimation comparing patient subgroups. Results: A total of 319 BC patients under adjuvant endocrine therapy and/or adjuvant chemotherapy were included. Curve-fitting analysis showed that for a BMI cut-off >29 in AI-treated BC patients (n = 172), DFS was increasingly deteriorating and that the impact of BMI on 2-year DFS identified a cut-off specific only for the cohort of postmenopausal BC patients under adjuvant therapy with AI. Conclusion: in radically resected hormone-sensitive BC patients undergoing neoadjuvant or adjuvant chemotherapy and treated with AI, obesity represents a risk factor for recurrence, with a significantly reduced 2-year DFS.

Association between Serum Biomarkers with Postoperative Complications and Delay of Adjuvant Chemotherapy Initiation in Ovarian Cancer Patients Undergoing Primary Cytoreductive Surgery: A Pilot Study

This study sought to describe and relate the factors associated with complications and delays in adjuvant chemotherapy in patients with ovarian cancer treated with primary cytoreductive surgery. Serum from patients diagnosed with ovarian cancer scheduled for primary cytoreductive surgery were analyzed for prealbumin, 25-OH Vitamin D, intracellular adhesion molecule 1 (ICAM-1), interleukin 6 (IL-6), interleukin 8 (IL-8), monocyte chemoattractant protein 1 (MCP-1), monocyte chemoattractant protein 2 (MCP-2), macrophage derived chemokine (MDC). Postoperative complications were identified using common terminology criteria for adverse events 4.0 and 30 day after surgery. Delays in adjuvant chemotherapy were defined as >1 week interval between surgery and initiation. Patients with postoperative complications (39.6%) were significantly older, had lower serum prealbumin levels, and higher serum IL-6 and IL-8 than those without. Univariate logistic regression found that age (OR: 1.12, 95%CI: 1.00-1.35) and IL-6 (OR: 1.02, 95%CI: 0.99-1.05) were associated with postoperative complications, whereas age remained significant after multivariate analysis (OR:1.14, 95%CI: 1.00-1.29). Patients with delays in chemotherapy exhibited greater BMI and lower 25-OH Vitamin D than those without. Multivariate analysis found that increasing levels of 25-OH Vitamin D were associated with a lower risk of delayed chemotherapy initiation after controlling for age, body mass index, and tumor grade (OR: 0.93, 95%CI:0.87-0.99). This work suggests that in addition to age being predictive of postoperative complications, serum 25-OH Vitamin D may a provide insight into a patient's risk for postsurgical delays in chemotherapy initiation. These findings should, however, be confirmed in a larger study including robust survival analysis.

Post-Diagnosis Vitamin D Supplement Use and Survival among Cancer Patients: A Meta-Analysis

Vitamin D administered pre-diagnostically has been shown to reduce mortality. Emerging evidence suggests a role of post-diagnosis vitamin D supplement intake for survival among cancer patients. Thus, we conducted a meta-analysis to evaluate the relationship. PubMed and Embase were searched for relevant observational cohort studies and randomized trials published through April 2022. Summary relative risk (SRR) and 95% confidence interval (CI) were estimated using the DerSimonian–Laird random-effects model. The SRR for post-diagnosis vitamin D supplement use vs. non-use, pooling cohort studies and randomized trials, was 0.87 (95% CI, 0.78–0.98; p = 0.02; I² = 0%) for overall survival, 0.81 (95% CI, 0.62–1.06; p = 0.12; I² = 51%) for progression-free survival, 0.86 (95% CI, 0.72–1.03; p = 0.10; I² = 0%) for cancer-specific survival, and 0.86 (95% CI, 0.64–1.14; p = 0.29; I² = 0%) for relapse. Albeit not significantly heterogeneous by variables tested, a significant inverse association was limited to cohort studies and supplement use during cancer treatment for overall survival, and to studies with ≤3 years of follow-up for progression-free survival. Post-diagnosis vitamin D supplement use was associated with improved overall survival, but not progression-free or cancer-specific survival or relapse. Our findings require confirmation, as randomized trial evidence was insufficient to establish cause-and-effect relationships.

Serum 25-hydroxyvitamin D and cancer-related fatigue: associations and effects on depression, anxiety, functional capacity and health-related quality of Life in breast cancer survivors during adjuvant endocrine therapy

Background

The adjuvant treatment with Aromatase Inhibitor (AI) is considered standard of care for postmenopausal breast cancer (BC) women with hormone receptor-positive (HR +), however, it often causes adverse effects such as cancer-related fatigue (CRF). The high prevalence of vitamin D deficiency in postmenopausal women who start adjuvant AI supports the hypothesis that hypovitaminosis D would be one of the biological explanations for toxicity of AI. This study aimed to identify the relationship between 25-hydroxyvitamin D [25(OH)D] and CRF, and to analyze their associations and effects on depression, anxiety, functional disability, muscle/joint aches and HRQL.

Methods

This prospective study included 89 postmenopausal women diagnosed with HR + early BC in adjuvant endocrine therapy with AI. Anthropometric and body composition assessments were performed, as well as dietary assessments by application of 24-h dietary recall, at three time points, totaling 24 months of follow-up. The women completed the Cervantes Scale (CS), Hospital Anxiety and Depression Scale (HADS) and Health Assessment Questionnaire (HAQ). The CRF was determined from the Functional Assessment of Chronic Illness Therapy-fatigue (FACIT-F). The serum 25(OH)D was determined by electrochemiluminescence, with cut-off point above 75 nmol/L adopted as sufficiency. Generalized Linear Model (GLzM) and Generalized Mixed Model (GMM) analysis were used.

Results

At baseline, 36% (n = 32) of the women presented CRF and 39.3% (n = 35) had 25(OH)D below 75 nmol/L. None of the women reached the Estimated Average Requirements (EAR) of vitamin D. The causality between 25(OH)D and CRF was not significant. Longitudinally, lower levels of 25(OH)D had a negative effect on anxiety (p = 0.020), Menopause and Health (p = 0.033) and Vasomotor scores (p = 0.007). Also, the CRF had a negative effect on anxiety (p = 0.028); depression (p = 0.027); functional disability (p = 0.022); HRQL (p = 0.007); Menopause and Health (p = 0.042), Psychological (p = 0.008) and Couple Relations (p = 0.008) domains; and on Health (p = 0.019) and Aging (p = 0.036) subdomains. Vasomotor subdomain (β = -2.279, p = 0.045) and muscle/joint aches (β = -0.779, p = 0.013) were significant with CRF only at baseline.

Conclusions

This study found negative effect of body adiposity on CRF. Still, the clinical relevance of 25(OH)D and CRF is highlighted, especially that of CRF, considering the consistent impact on several adverse effects reported by BC survivors during adjuvant endocrine therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09962-x.

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.

Negative Impact of Vitamin D Deficiency at Diagnosis on Breast Cancer Survival: A Prospective Cohort Study

Objective. We prospectively evaluated the association between vitamin D concentration at diagnosis and overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS) in postmenopausal women treated for breast cancer. Methods. This study included 192 patients newly diagnosed with invasive breast cancer, aged ≥45 years, and serum 25-hydroxy vitamin D (25 (OH)D) concentration assessment at diagnosis. Patients were classified into groups according to 25 (OH)D concentrations: sufficient (≥30 ng/mL), insufficient (between 20 and 29 ng/mL), and deficient (<20 ng/mL). The primary outcome was OS, and the secondary outcomes were DFS and CSS. The Kaplan–Meier curve and Cox regression model were used to assess the association between 25 (OH)D concentrations and survival rates. Differences in survival were evaluated by hazard ratios (HRs). Results. The mean age was 61.3 ± 9.6 years, 25 (OH)D concentration was 26.9 ± 7.5 ng/mL (range 12.0–59.2 ng/mL), and the follow-up period was between 54 and 78 months. Sufficient 25 (OH)D was detected in 33.9% of patients, insufficient in 47.9%, and deficient in 18.2%. A total of 51 patients (26.6%) died during the study period, with a mean OS time of 54.4 ± 20.2 months (range 9–78 months). Patients with 25 (OH)D deficiency and insufficiency at diagnosis had a significantly lower OS, DFS, and CSS compared with patients with sufficient values ( $p<\text{0}.001$ ). After adjustment for clinical and tumoral prognostic factors, patients with 25 (OH)D concentrations considered deficient at diagnosis had a significantly higher risk of global death (HR, 4.65; 95% CI, 1.65–13.12), higher risk of disease recurrence (HR, 6.87; 95% CI, 2.35–21.18), and higher risk of death from the disease (HR, 5.91; 95% CI, 1.98–17.60) than the group with sufficient 25(OH)D concentrations. Conclusion. In postmenopausal women treated for breast cancer, vitamin D deficiency and insufficiency at diagnosis were independently associated with lower OS, DFS, and CSS compared with patients with sufficient 25(OH)D concentrations.

The Multiple Effects of Vitamin D against Chronic Diseases: From Reduction of Lipid Peroxidation to Updated Evidence from Clinical Studies

Background: Vitamin D exerts multiple beneficial effects in humans, including neuronal, immune, and bone homeostasis and the regulation of cardiovascular functions. Recent studies correlate vitamin D with cancer cell growth and survival, but meta-analyses on this topic are often not consistent. Methods: A systematic search of the PubMed database and the Clinical Trial Register was performed to identify all potentially relevant English-language scientific papers containing original research articles on the effects of vitamin D on human health. Results: In this review, we analyzed the antioxidant and anti-inflammatory effects of vitamin D against acute and chronic diseases, focusing particularly on cancer, immune-related diseases, cardiomyophaties (including heart failure, cardiac arrhythmias, and atherosclerosis) and infectious diseases. Conclusions: Vitamin D significantly reduces the pro-oxidant systemic and tissue biomarkers involved in the development, progression, and recurrence of chronic cardiometabolic disease and cancer. The overall picture of this review provides the basis for new randomized controlled trials of oral vitamin D supplementation in patients with cancer and infectious, neurodegenerative, and cardiovascular diseases aimed at reducing risk factors for disease recurrence and improving quality of life.

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

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

A Randomized Trial of Calcium Plus Vitamin D Supplementation and Risk of Ductal Carcinoma In Situ of the Breast

Background

The effect of calcium plus vitamin D (CaD) supplementation on risk of ductal carcinoma in situ (DCIS) of the breast, a nonobligate precursor of invasive ductal carcinoma, is not well understood. In this secondary analysis, we examined this association in the Women’s Health Initiative CaD trial over approximately 20 years of follow-up.

Methods

A total of 36 282 cancer-free postmenopausal women (50-79 years) were randomly assigned to daily (d) calcium (1000 mg) plus vitamin D (400 IU) supplementation or to a placebo. Personal supplementation with vitamin D (≤600 IU/d, subsequently raised to 1000 IU/d) and calcium (≤1000 mg/d) was allowed. The intervention phase (median = 7.1 years), was followed by a postintervention phase (additional 13.8 years), which included 86.0% of the surviving women. A total of 595 incident DCIS cases were ascertained. Hazard ratios (HRs) plus 95% confidence intervals (CIs) were calculated.

Results

The intervention group had a lower risk of DCIS throughout follow-up (HR = 0.82, 95% CI = 0.70 to 0.96) and during the postintervention phase (HR = 0.76, 95% CI = 0.61 to 0.94). The group that used CaD personal supplements in combination with the trial intervention had a lower risk of DCIS compared with the trial placebo group that did not use personal supplementation (HR = 0.72, 95% CI = 0.56 to 0.91).

Conclusions

CaD supplementation in postmenopausal women was associated with reduced risk of DCIS, raising the possibility that consistent use of these supplements might provide long-term benefits for the prevention of DCIS.

Drivers and suppressors of triple-negative breast cancer

To identify regulators of triple-negative breast cancer (TNBC), gene expression profiles of malignant parts of TNBC (mTNBC) and normal adjacent (nadj) parts of the same breasts have been compared. We are interested in the roles of estrogen receptor β (ERβ) and the cytochrome P450 family (CYPs) as drivers of TNBC. We examined by RNA sequencing the mTNBC and nadj parts of five women. We found more than a fivefold elevation in mTNBC of genes already known to be expressed in TNBC: BIRC5/survivin, Wnt-10A and -7B, matrix metalloproteinases (MMPs), chemokines, anterior gradient proteins, and lysophosphatidic acid receptor and the known basal characteristics of TNBC, sox10, ROPN1B, and Col9a3. There were two unexpected findings: 1) a strong induction of CYPs involved in activation of fatty acids (CYP4), and in inactivation of calcitriol (CYP24A1) and retinoic acid (CYP26A1); and 2) a marked down-regulation of FOS, FRA1, and JUN, known tethering partners of ERβ. ERβ is expressed in 20 to 30% of TNBCs and is being evaluated as a target for treating TNBC. We used ERβ⁺ TNBC patient-derived xenografts in mice and found that the ERβ agonist LY500703 had no effect on growth or proliferation. Expression of CYPs was confirmed by immunohistochemistry in formalin-fixed and paraffin-embedded (FFPE) TNBC. In TNBC cell lines, the CYP4Z1-catalyzed fatty acid metabolite 20-hydroxyeicosatetraenoic acid (20-HETE) increased proliferation, while calcitriol decreased proliferation but only after inhibition of CYP24A1. We conclude that CYP-mediated pathways can be drivers of TNBC but that ERβ is unlikely to be a tumor suppressor because the absence of its main tethering partners renders ERβ functionless on genes involved in proliferation and inflammation.

Effect of cytotoxic chemotherapy on bone health among breast cancer patients. Does it require intervention?

BACKGROUND

Breast cancer (BC) is one of the most common malignancies worldwide. Although the burden and mechanisms of endocrine therapy-related bone loss are known, the evidence is scanty regarding the impact of cytotoxic chemotherapy on bone health. We have attempted to summarize the effect of cytotoxic chemotherapy on bone health in BC patients.

METHODS

A comprehensive literature search was performed via MEDLINE and Cochrane library databases to evaluate the effect of chemotherapy on bone health among women with BC. We included articles related to skeletal-related events, bone mineral density, bone turnover markers, osteoporosis-specific quality of life, bisphosphonate, and other bone-directed therapy. We excluded articles that included patients with metastatic breast cancer and patients receiving hormonal therapy.

DISCUSSION

Bone microenvironment in cancer is directly or indirectly influenced by clinical, hormonal, nutritional, and treatment factors. Calcitonin, parathyroid hormone, calcitriol, and estrogen are the major hormonal regulators. Bone turnover markers, namely bone formation and resorption markers, have been used to predict bone loss, fracture risk, and monitoring treatment response. Chemotherapeutic drugs such as anthracyclines and taxanes synergistically affect BMD and quality of life. Calcium, vitamin D, bisphosphonates, and denosumab are supplemented to prevent excess bone resorption. Bone-targeted anti-resorptive agents have been studied as potential anticancer agents in the adjuvant treatment of breast cancer.

CONCLUSION

This review summarizes the negative effect of chemotherapy on bone health of BC patients and the importance of preventing or treating bone loss.

Sex Differences in Photoprotective Responses to 1,25-Dihydroxyvitamin D3 in Mice Are Modulated by the Estrogen Receptor-β

Susceptibility to photoimmune suppression and photocarcinogenesis is greater in male than in female humans and mice and is exacerbated in female estrogen receptor-beta knockout (ER-β−/−) mice. We previously reported that the active vitamin D hormone, 1,25-dihydroxyvitamin D3 (1,25(OH)2D), applied topically protects against the ultraviolet radiation (UV) induction of cutaneous cyclobutane pyrimidine dimers (CPDs) and the suppression of contact hypersensitivity (CHS) in female mice. Here, we compare these responses in female versus male Skh:hr1 mice, in ER-β−/−/−− versus wild-type C57BL/6 mice, and in female ER-blockaded Skh:hr1 mice. The induction of CPDs was significantly greater in male than female Skh:hr1 mice and was more effectively reduced by 1,25(OH)2D in female Skh:hr1 and C57BL/6 mice than in male Skh:hr1 or ER-β−/− mice, respectively. This correlated with the reduced sunburn inflammation due to 1,25(OH)2D in female but not male Skh:hr1 mice. Furthermore, although 1,25(OH)2D alone dose-dependently suppressed basal CHS responses in male Skh:hr1 and ER-β−/− mice, UV-induced immunosuppression was universally observed. In female Skh:hr1 and C57BL/6 mice, the immunosuppression was decreased by 1,25(OH)2D dose-dependently, but not in male Skh:hr1, ER-β−/−, or ER-blockaded mice. These results reveal a sex bias in genetic, inflammatory, and immune photoprotection by 1,25(OH)2D favoring female mice that is dependent on the presence of ER-β.

Immunomodulatory effects of vitamin D3 on gene expression of MDGF, EGF and PDGFB in endometriosis

RESEARCH QUESTION

Endometriosis, an inflammatory disease, is assumed to be associated with an increased production of growth-related cytokines. Based on the emerging immunomodulatory role of vitamin D3 in different inflammatory conditions, this study aimed to examine its modulatory effect on the expression levels of the genes for platelet-derived growth factor-B (PDGFB), monocyte/macrophage-derived growth factor (MDGF, also known as PPBP) and epidermal growth factor (EGF) in peritoneal fluid mononuclear cells (PFMC) in women with and without endometriosis.

DESIGN

PFMC from 10 women with endometriosis and 10 control participants were treated with vitamin D3.The gene expression levels of PDGFB, MDGF and EGF were measured 6, 24 and 48 h following vitamin D3 administration using real-time PCR.

RESULTS

Gene expression levels of EGF and PDGFB were higher in the PFMC of women with endometriosis than the control group (P = 0.006, P < 0.001, respectively). Although MDGF expression showed an increase in the endometriosis group compared with non-endometriotic controls, no significant difference was found. Vitamin D3 significantly decreased EGF expression at 6, 24 and 48 h (P < 0.001, P < 0.001 and P = 0.007, respectively), MDGF at 24 and 48 h (P < 0.001 and P = 0.009, respectively) and PDGFB at 6 h (P = 0.047) in the endometriosis group. Vitamin D3 treatment had no significant effect on expression of the genes in the PFMC of non-endometriotic women.

CONCLUSIONS

The study concluded that PDGFB and EGF gene expression increases in endometriosis, and vitamin D3 could markedly decrease this expression, suggesting its therapeutic potential in endometriosis.

Prediagnostic 25-Hydroxyvitamin D Concentrations in Relation to Tumor Molecular Alterations and Risk of Breast Cancer Recurrence

BACKGROUND

Although vitamin D inhibits breast tumor growth in experimental settings, the findings from population-based studies remain inconclusive. Our goals were to investigate the association between prediagnostic plasma 25-hydroxyvitamin D [25(OH)D] concentration and breast cancer recurrence in prospective epidemiologic studies and to explore the molecular underpinnings linking 25(OH)D to slower progression of breast cancer in the Nurses' Health Studies (NHS, N = 659).

METHODS

Plasma 25(OH)D was measured with a high-affinity protein-binding assay and a radioimmunoassay. We profiled transcriptome-wide gene expression in breast tumors using microarrays. Hazard ratios (HR) of breast cancer recurrence were estimated from covariate-adjusted Cox regressions. We examined differential gene expression in association with 25(OH)D and employed pathway analysis. We derived a gene expression score for 25(OH)D, and assessed associations between the score and cancer recurrence.

RESULTS

Although 25(OH)D was not associated with breast cancer recurrence overall [HR = 0.97; 95% confidence interval (CI), 0.88-1.08], the association varied by estrogen-receptor (ER) status (P _interaction = 0.005). Importantly, among ER-positive stage I to III cancers, every 5 ng/mL increase in 25(OH)D was associated with a 13% lower risk of recurrence (HR = 0.87; 95% CI, 0.76-0.99). A null association was observed for ER-negative cancers (HR = 1.07; 95% CI, 0.91-1.27). Pathway analysis identified multiple gene sets that were significantly (FDR < 5%) downregulated in ER-positive tumors of women with high 25(OH)D (≥30 ng/mL), compared with those with low levels (<30 ng/mL). These gene sets are primarily involved in tumor proliferation, migration, and inflammation. 25(OH)D score derived from these gene sets was marginally associated with reduced risk of recurrence in ER-positive diseases (HR = 0.77; 95% CI, 0.59-1.01) in the NHS studies; however no association was noted in METABRIC, suggesting that further refinement is need to improve the generalizability of the score.

CONCLUSIONS

Our findings support an intriguing line of research for studies to better understand the mechanisms underlying the role of vitamin D in breast tumor progression, particularly for the ER-positive subtype.

IMPACT

Vitamin D may present a personal-level secondary-prevention strategy for ER-positive breast cancer.

Consensus statement from 2nd International Conference on Controversies in Vitamin D

The 2nd International Conference on Controversies in Vitamin D was held in Monteriggioni (Siena), Italy, September 11-14, 2018. The aim of this meeting was to address ongoing controversies and timely topics in vitamin D research, to review available data related to these topics and controversies, to promote discussion to help resolve lingering issues and ultimately to suggest a research agenda to clarify areas of uncertainty. Several issues from the first conference, held in 2017, were revisited, such as assays used to determine serum 25-hydroxyvitamin D [25(OH)D] concentration, which remains a critical and controversial issue for defining vitamin D status. Definitions of vitamin D nutritional status (i.e. sufficiency, insufficiency and deficiency) were also revisited. New areas were reviewed, including vitamin D threshold values and how they should be defined in the context of specific diseases, sources of vitamin D and risk factors associated with vitamin D deficiency. Non-skeletal aspects related to vitamin D were also discussed, including the reproductive system, neurology, chronic kidney disease and falls. The therapeutic role of vitamin D and findings from recent clinical trials were also addressed. The topics were considered by 3 focus groups and divided into three main areas: 1) "Laboratory": assays and threshold values to define vitamin D status; 2) "Clinical": sources of vitamin D and risk factors and role of vitamin D in non-skeletal disease and 3) "Therapeutics": controversial issues on observational studies and recent randomized controlled trials. In this report, we present a summary of our findings.

Vitamin D and Demyelinating Diseases: Neuromyelitis Optica (NMO) and Multiple Sclerosis (MS)

Vitamin D deficiency is prevalent in all ages regardless of climate or geographical location and evidence is emerging that the incidence of autoimmune diseases is increasing worldwide. Women make up a large proportion of autoimmune disease diagnoses, underscoring the importance of fully elucidating the complex synergistic relationships between estrogens and vitamin D. Vitamin D receptor-activating drugs appear to enhance remyelination in patients diagnosed with multiple sclerosis (MS) and other demyelinating diseases such as neuromyelitis optica (NMO). This review is intended to update health practitioners about the potential role of vitamin D deficiency demyelination and to motivate future research on dietary recommendations for vitamin D in preventing and treating demyel1nating diseases.

Mammary-specific ablation of Cyp24a1 inhibits development, reduces proliferation and increases sensitivity to vitamin D

Active vitamin D (1,25(OH)2D) has been shown to regulate numerous cell processes in mammary cells. Degradation of 1,25(OH)2D is initiated by the mitochondrial enzyme, 25-hydroxyvitamin D 24-hydroxylase (CYP24 A1), and provides local control of 1,25(OH)2D bioactivity. Several reports of the association between elevated CYP24 A1 activity and breast cancer incidence, suggest that CYP24 A1 may be a target for therapeutic intervention. Whether CYP24 A1 activity within the mammary epithelium regulates 1,25(OH)2D levels and mammary gland development is yet to shown. We have used a conditional knockout of the Cyp24a1 gene specifically in the mammary epithelium to demonstrate reduced terminal end bud number, ductal outgrowth and branching during puberty and alveologenesis at early pregnancy, by inhibiting proliferation but not apoptosis in both basal and luminal MECs. In vitro study showed increased sensitivity of luminal MECs to lower levels of 1,25(OH)2D with the ablation of Cyp24a1 activity. In summary, Cyp24a1 within MECs plays an important role in modulating postnatal and pregnancy-associated mammary gland development which provides support for inhibiting CYP24 A1 as a potential approach to activating the vitamin D pathway in breast cancer prevention and therapy.

Assessing the effect of omega-3 fatty acid combined with vitamin D3 versus vitamin D3 alone on estradiol levels: a randomized, placebo-controlled trial in females with vitamin D deficiency

Purpose

Outcomes investigating the effect of vitamin D3 (VD3) and omega-3 fatty acids (Omega-3FA) on serum estradiol (E2) are scarce and conflicting. No previous study has investigated the effect of VD3 combination with Omega-3FA on E2 levels. This study was designed to investigate the effect of VD3, Omega-3FA and VD3 plus Omega-3FA on serum E2 levels in premenopausal females diagnosed with vitamin D deficiency (VDD).

Subjects and methods

This randomized, placebo-controlled clinical trial was designed to evaluate the effects of 50,000 IU VD3 taken weekly, 300 mg Omega-3FA taken daily and their combination by the study participants for 8 weeks. The mid-follicular serum levels of E2 and 25-hydroxy vitamin D (25OHD) were assessed at 8 weeks. The study was conducted during winter on a convenience sample of healthy premenopausal Jordanian females with diagnosed VDD. Fasting serum levels for 25OHD and E2 were assessed at baseline and the end of the trial (after 8 weeks). Data were entered into SPSS and analyzed.

Results

Healthy premenopausal Jordanian females (N=86) with diagnosed VDD, mean age 32.8±8.9 years, were recruited into the study. Supplementation of VD3 alone resulted in a significant increase in serum 25OHD (13.4±7.9–28.2±7.1 ng/mL, P<0.001) and a significant decrease in E2 levels (85.7±16.5–60.3±20.6 pg/mL, P=0.001). Omega-3FA intake led to a significant decrease in serum 25OHD levels (21.2±12.8–13.6±9.2 ng/mL, P=0.001) and a significant increase in E2 levels (56.3±19.2–78.4±23.7 pg/mL, P=0.006). Combination therapy (VD3 plus Omega-3FA) resulted in a significant increase in both 25OHD (12.0±4.7–35.1±9.5 ng/mL, P<0.001) and E2 (43.0±23.4–57.3±31.5 pg/mL, P=0.028) levels.

Conclusion

Results of this study provide vital insight into the effects of D3, Omega-3FA and a combination of their supplementation on premenopausal Jordanian females with diagnosed VDD. Eight weeks of therapy led to decreased E2 level by VD3 and increased level by Omega-3FA supplementation. With regard to 25OHD, its level was increased by VD3 and decreased by Omega-3FA supplementation. Combination of VD3 plus Omega-3FA increased the levels of both E2 and 25OHD.

Trial registration

This trial was registered at clinicaltrials.gov as NCT03333564.

Polymeric nanocapsules as drug carriers for sustained anticancer activity of calcitriol in breast cancer cells

Clinical use of calcitriol (1,25-dihydroxyvitamin D₃) as an anticancer agent is currently limited by the requirement of supraphysiological doses and associated hypercalcemia. Nanoencapsulation of calcitriol is a strategy to overcome these drawbacks, allowing reduced administrated doses and/or frequency, while retaining the therapeutic activity towards cancer cells. For this purpose, we investigated the impact of calcitriol encapsulation on its antiproliferative activity and optimized formulation parameters with that respect. Calcitriol-loaded polymeric nanoparticles with different polymer:oil ratios were prepared by the nanoprecipitation method. Nanoparticles had similar mean size (200 nm) and EE (85%) whereas their release profile strongly depended on formulation parameters. Antiproliferative and cytotoxic activities of formulated calcitriol were evaluated in vitro using human breast adenocarcinoma cells (MCF-7) and showed that calcitriol-induced cell growth inhibition was closely related to its release kinetics. For the most suitable formulation, a sustained cell growth inhibition was observed over 10 days compared to free form. Advantages of calcitriol encapsulation and the role of formulation parameters on its biological activity in vitro were demonstrated. Selected nanoparticle formulation is a promising calcitriol delivery system ensuring a prolonged anticancer activity that could improve its therapeutic efficiency.

Impact of vitamin D on pathological complete response and survival following neoadjuvant chemotherapy for breast cancer: a retrospective study

Background

There has been interest in the potential benefit of vitamin D (VD) to improve breast cancer outcomes. Pre-clinical studies suggest VD enhances chemotherapy-induced cell death. Vitamin D deficiency was associated with not attaining a pathologic complete response (pCR) following neoadjuvant chemotherapy (NAC) for operable breast cancer. We report the impact of VD on pCR and survival in an expanded cohort.

Methods

Patients from Iowa and Montpellier registries who had serum VD level measured before or during NAC were included. Vitamin D deficiency was defined as < 20 ng/mL. Pathological complete response was defined as no residual invasive disease in the breast and lymph nodes. Survival was defined from the date of diagnosis to the date of relapse (PFS) or date of death (OS).

Results

The study included 327 women. Vitamin D deficiency was associated with the odds of not attaining pCR (p = 0.04). Fifty-four patients relapsed and 52 patients died. In multivariate analysis, stage III disease, triple-negative (TN) subtype and the inability to achieve pCR were independently associated with inferior survival. Vitamin D deficiency was not significantly associated with survival in the overall sample; however a trend was seen in the TN (5-years PFS 60.4% vs. 72.3%, p = 0.3), and in the hormone receptor positive /human epidermal growth factor receptor 2 negative (HER2-) subgroups (5-years PFS 89% vs 78%, p = 0.056).

Conclusion

Vitamin D deficiency is associated with the inability to reach pCR in breast cancer patients undergoing NAC.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4686-x) contains supplementary material, which is available to authorized users.

Vitamin D3 regulates steroidogenesis in granulosa cells through AMP-activated protein kinase (AMPK) activation in a mouse model of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is an endocrine and metabolic disorder in reproductive-aged women. Hormonal abnormality caused by steroidogenesis disturbances appears to be the main culprit of the clinical picture in PCOS. Vitamin D3 could regulate steroidogenesis in granulosa cells, but the mechanism of action of vitamin D3 on steroidogenesis remains unknown. AMP-activated protein kinase (AMPK) has a modulating role in steroid hormone production. We investigated the effect of vitamin D3 on steroidogenesis in cultured granulosa cells of dehydroepiandrosterone-induced PCOS mice and studied the involvement of AMPK signalling pathway in the current process. Immunoblotting assay showed that vitamin D3 could increase phosphorylation of AMPK alpha and acetyl-CoA carboxylase, main substrate of AMPK. Vitamin D3 and 5-aminoimidazole-4-carboxamide-1-β-D-riboside or Aicar (AMPK activator) not only reduced gene expression of steroidogenic enzymes (P450scc or Cyp11a1, StAR, Cyp19a1 and 3B-HSD), but also reduced production of progesterone and 17B-estradiol assessed by radioimmunoassay. Pretreatment with compound C (AMPK inhibitor) decreased APMK phosphorylation and eliminated the effects of vitamin D3 and Aicar on steroidogenic enzymes expression and estradiol and progesterone production. This study showed that vitamin D3 has the main role in regulating of steroidogenesis in granulosa cells of mouse polycystic ovary through activation of the AMPK signalling pathway.

SIGNIFICANCE OF THE STUDY

Polycystic ovarian syndrome (PCOS) is an endocrine disorder of women in reproductive age. This disorder is partly related to disruption in steroidogenesis pathway and dysregulation of estradiol and progesterone production in granulosa cells of polycystic ovaries. Previously, we have shown that vitamin D3 could modulate steroidogenesis pathway in PCOS granulosa cells. In this study, we investigate the molecular mechanism of vitamin D3 in regulation of steroidogenesis pathway. We have shown that vitamin D3 has a modulating role in steroidogenesis pathway of granulosa cells by regulation of AMP-activated protein kinase (AMPK) as an underlying molecular mechanism in mouse polycystic ovary.

Estrogen: The necessary evil for human health, and ways to tame it

Estrogen is a pivotal enzyme for survival and health in both genders, though their quantum, tropism, tissue-specific distribution, and receptor affinity varies with different phases of life. Converted from androgen via aromatase enzyme, this hormone is indispensable to glucose homeostasis, immune robustness, bone health, cardiovascular health, fertility, and neural functions. However, estrogen is at the center of almost all human pathologies as well-infectious, autoimmune, metabolic to degenerative. Both hypo and hyper level of estrogen has been linked to chronic and acute diseases. While normal aging is supposed to lower its level, leading to tissue degeneration (bone, muscle, neural etc.), and metabolite imbalance (glucose, lipid etc.), the increment in inflammatory agents in day-to-day life are enhancing the estrogen (or estrogen mimic) level, fueling 'estrogen dominance'. The resultant excess estrogen is inducing an overexpression of estrogen receptors (ERα and ERβ), harming tissues, leading to autoimmune diseases, and neoplasms. The unprecedented escalation in the polycystic ovary syndrome, infertility, breast cancer, ovary cancer, and gynecomastia cases are indicating that this sensitive hormone is getting exacerbated. This critical review is an effort to analyze the dual, and opposing facets of estrogen, via understanding its crosstalk with other hormones, enzymes, metabolites, and drugs. Why estrogen level correction is no trivial task, and how it can be restored to normalcy by a disciplined lifestyle with wise dietary and selective chemical usage choices has been discussed. Overall, our current state of knowledge does not disclose the full picture of estrogen's pleiotropic importance. Hence, this review should be a resource for general public as well as researchers to work in that direction.

Identification of tumor-autonomous and indirect effects of vitamin D action that inhibit breast cancer growth and tumor progression

Several epidemiological studies have found that low vitamin D levels are associated with worse prognosis and poorer outcomes in patients with breast cancer (BCa), although some studies have failed to find this association. In addition, prior research has found that BCa patients with vitamin D deficiency have a more aggressive molecular phenotype and worse prognostic biomarkers. As vitamin D deficiency is common in patients diagnosed with BCa, elucidating the cause of the association between poor outcomes and vitamin D deficiency promises to have a significant impact on improving care for patients with BCa including enabling the development of novel therapeutic approaches. Here we review our recent findings in this area, including our data revealing that reduction of the expression of the vitamin D receptor (Vdr) within BCa cells accelerates primary tumor growth and enables the development of metastases, demonstrating a tumor autonomous effect of vitamin D signaling to suppress BCa metastases. We believe that these findings are likely relevant to humans as we discovered evidence that a mechanism of VDR regulation identified in our mouse models is conserved in human BCa. In particular, we identified a negative correlation between serum 25(OH)D concentration and the level of expression of the tumor progression factor ID1 in primary tumors from patients with breast cancer.

Effects of vitamin D supplementation during weight loss on sex hormones in postmenopausal women

OBJECTIVE

The aim of the study was to compare the effects of vitamin D3 supplementation versus placebo on serum sex hormones in postmenopausal women completing a 12-month diet + exercise weight loss program.

METHODS

Two hundred eighteen overweight or obese women (50-75 y) with serum 25-hydroxyvitamin D at least 10 to less than 32 ng/mL ("insufficient") were randomized to either weight loss + 2,000 IU/day oral vitamin D3, or to weight loss + daily placebo. Serum sex hormone-binding globulin, estrone, total, free, and bioavailable estradiol, and testosterone were measured by radioimmunoassay before randomization and at 12 months. Mean changes were compared between groups (intent-to-treat) using generalized estimating equations.

RESULTS

The 12-month changes in sex hormone-binding globulin, estrone, total, free, and bioavailable estradiol, and testosterone did not differ between groups (all P > 0.05). However, a greater increase in serum 25-hydroxyvitamin D was associated with a greater increase in sex hormone-binding globulin (Ptrend = 0.01), and larger decreases in free and bioavailable estradiol (Ptrend = 0.04, Ptrend = 0.03, respectively). In post-hoc analyses, we compared women randomized to vitamin D whose serum 25-hydroxyvitamin D remained insufficient (n = 38), to women who became replete (25-hydroxyvitamin D ≥32 ng/mL; n = 53). Replete women showed greater reductions in bioavailable estradiol (-1.8 vs -0.7 pg/mL), free testosterone (-0.8 vs -0.3 pg/mL), and bioavailable testosterone (-1.8 vs -0.6 ng/dL), and a greater increase in sex hormone-binding globulin (10.6 vs 4.7 nmol/L) (all P < 0.05), even after adjusting for differences in total 12-month weight loss.

CONCLUSIONS

Overall, 12-month changes in sex hormone did not differ between groups. However, vitamin D repletion was associated with greater reductions in sex hormones during weight loss, with a possible dose-dependent effect. Future studies should test higher doses and target circulating 25-hydroxyvitamin D levels when measuring such effects.

Vitamin D, the placenta and early pregnancy: effects on trophoblast function

Pregnancy is associated with significant changes in vitamin D metabolism, notably increased maternal serum levels of active vitamin D, 1,25-dihydroxyvitamin (1,25(OH)₂D). This appears to be due primarily to increased renal activity of the enzyme 25-hydroxyvitamin D-1α-hydroxylase (CYP27B1) that catalyzes synthesis of 1,25(OH)₂D, but CYP27B1 expression is also prominent in both the maternal decidua and fetal trophoblast components of the placenta. The precise function of placental synthesis of 1,25(OH)₂D remains unclear, but is likely to involve localized tissue-specific responses with both decidua and trophoblast also expressing the vitamin D receptor (VDR) for 1,25(OH)₂D. We have previously described immunomodulatory responses to 1,25(OH)₂D by diverse populations of VDR-expressing cells within the decidua. The aim of the current review is to detail the role of vitamin D in pregnancy from a trophoblast perspective, with particular emphasis on the potential role of 1,25(OH)₂D as a regulator of trophoblast invasion in early pregnancy. Vitamin D deficiency is common in pregnant women, and a wide range of studies have linked low vitamin D status to adverse events in pregnancy. To date, most of these studies have focused on adverse events later in pregnancy, but the current review will explore the potential impact of vitamin D on early pregnancy, and how this may influence implantation and miscarriage.

Vitamin D analogues: Potential use in cancer treatment

The vitamin D receptor (VDR) is a member of the thyroid-steroid family of nuclear transcription factors. Following binding of the active form of vitamin D, i.e., 1,25(OH)₂D3 (also known as calcitriol) and interaction with co-activators and co-repressors, VDR regulates the expression of several different genes. Although relatively little work has been carried out on VDR in human cancers, several epidemiological studies suggest that low circulating levels of vitamin D are associated with both an increased risk of developing specific cancer types and poor outcome in patients with specific diagnosed cancers. These associations apply especially in colorectal and breast cancer. Consistent with these findings, calcitriol as well as several of its synthetic analogues have been shown to inhibit tumor cell growth in vitro and in diverse animal model systems. Indeed, some of these vitamin D analogues with low calcemic inducing activity (e.g., EB1089, inecalcitol, paricalcitol) have progressed to clinical trials in patients with cancer. Preliminary results from these trials suggest that these vitamin D analogues have minimal toxicity, but clear evidence of efficacy remains to be shown. Although evidence of efficacy for mono-treatment with vitamin D analogues is currently lacking, several studies have reported that supplementation with calcitriol or the presence of high endogenous circulating levels of vitamin D enhances response to standard therapies.

Gene expression in breast and adipose tissue after 12 months of weight loss and vitamin D supplementation in postmenopausal women

Adipose tissue is involved in the etiology of postmenopausal breast cancer, possibly through increased sex steroid hormone production, inflammation, and altered adipokines. Vitamin D may affect these pathways but its effect on gene expression in different tissues has not been examined. Within a double-blind, 12-month placebo-controlled randomized trial, we compared 2000 IU/day oral vitamin D₃ supplementation (N = 39) vs. placebo (N = 40) on the expression of 5 genes in breast and adipose tissue in overweight/obese postmenopausal women (50-75 years). All participants had serum 25-hydroxyvitamin D (25(OH)D) levels ≥ 10-<32 ng/mL ("insufficient") and concurrently completed a behavioral weight loss program. Random periareolar fine needle aspiration (RPFNA) and abdominal subcutaneous adipose tissue biopsies were performed at baseline and 12 months. Changes in expression of aromatase (CYP19A1), peroxisome proliferator-activated receptor gamma (PPARG), adiponectin (ADIPOQ), monocyte-chemoattractant protein 1 (MCP-1), and vitamin D receptor (VDR) were analyzed by qRT-PCR. Compared to placebo, 2000 IU vitamin D did not show significant effects on gene expression in breast or adipose tissue. Replete women (i.e., 25(OH)D ≥ 32 ng/mL; N = 17) showed a small decrease in MCP-1 expression compared to an increase among women who remained 'insufficient' despite supplementation (N = 12) (Replete:-1.6% vs. Non-replete: 61.2%, p = 0.015) in breast, but not adipose tissue. No statistically significant differences in gene expression were detected according to degree of weight loss. Vitamin D repletion during weight loss may have different effects on gene expression in breast and adipose tissue. Further research on the localized effects of vitamin D is needed to determine its effect on breast cancer risk.

Influence of vitamin D signaling on hormone receptor status and HER2 expression in breast cancer

PURPOSE

Breast cancer is a significant global public health issue. It is the leading cause of death among women around the world, with an incidence increasing annually. In recent years, there has been more and more information in the literature regarding a protective role of vitamin D in cancer. Increasingly preclinical and clinical studies suggest that vitamin D optimal levels can reduce the risk of breast cancer development and regulate cancer-related pathways.

METHOD

In this review, we focus on the importance of vitamin D in breast cancers, discussing especially the influence of vitamin D signaling on estrogen receptor and human epidermal growth factor receptor 2 (HER2), two major biomarkers of breast cancer today.

CONCLUSION

We discuss the possibility of actual and future targeted therapeutic approaches for vitamin D signaling in breast cancer.

Calcitriol Inhibits Cervical Cancer Cell Proliferation Through Downregulation of HCCR1 Expression

Calcitriol (1α,25-dihydroxyvitamin D3) has demonstrated anticancer activity against several tumors. However, the underlying mechanism for this activity is not yet fully understood. Our experiment was designed and performed to address one aspect of this issue in cervical cancer. HeLa S3 cells were cultured in media with various concentrations of calcitriol. Cell proliferation and cell cycle were assessed by spectrophotometry and flow cytometry, respectively. The mRNA and protein expression levels of human cervical cancer oncogene (HCCR-1) and p21 were determined by RT-PCR and Western blot, respectively. Results indicated that calcitriol inhibited HeLa S3 cell proliferation and induced cell cycle arrest at the G₁ phase. Calcitriol decreased HCCR-1 protein expression in a dose- and time-dependent manner. Furthermore, promoter activity analyses revealed that transcriptional regulation was involved in the inhibition of HCCR-1 expression. Overexpression of HCCR-1 in HeLa S3 cells reversed the inhibition of cell proliferation and G₁ phase arrest that resulted from calcitriol treatment. In addition, calcitriol increased p21 expression and promoter activity. HCCR-1 overexpression decreased p21 expression and promoter activity. Thus, our results suggested that calcitriol inhibited HeLa S3 cell proliferation by decreasing HCCR-1 expression and increasing p21 expression.

Regulation of the CCN genes by vitamin D: A possible adjuvant therapy in the treatment of cancer and fibrosis

The CCN family is composed of six cysteine-rich, modular, and conserved proteins whose functions span a variety of tissues and include cell proliferation, adhesion, angiogenesis, and wound healing. Roles for the CCN proteins throughout the entire body including the skin, kidney, brain, blood vessels, hematopoietic compartment and others, are continuously being elucidated. Likewise, an understanding of the regulation of this important gene family is constantly becoming clearer, through identification of transcription factors that directly activate, repress, or respond to upstream cell signaling pathways, as well as other forms of gene expression control. Vitamin D (1,25-dihydroxyvitamin D3 or calcitriol), a vitamin essential for numerous biological processes, acts as a potent gene expression modulator. The regulation of the CCN gene family members by calcitriol has been described in many contexts. Here, we provide a concise and thorough overview of what is known about calcitriol and its regulation of the CCN genes, and argue that its regulation is of physiological importance in a wide breadth of tissues in which CCN genes function. In addition, we highlight the effects of vitamin D on CCN gene expression in the setting of two common pathologic conditions, fibrosis and cancer, and propose that the therapeutic effects of vitamin D3 described in these disease states may in part be attributable to CCN gene modulation. As vitamin D is perfectly safe in a wide range of doses and already showing promise as an adjuvant therapeutic agent, a deeper understanding of its control of CCN gene expression may have profound implications in clinical management of disease.

Vitamin D mitigates the adverse effects of obesity on breast cancer in mice

Obesity is an established risk factor for postmenopausal breast cancer (BCa), insulin resistance, and vitamin D deficiency, and all contribute to increased synthesis of mammary estrogens, the drivers of estrogen receptor-positive (ER+) BCa growth. As both dietary vitamin D and calcitriol treatments inhibit breast estrogen synthesis and signaling, we hypothesized that vitamin D would be especially beneficial in mitigating the adverse effects of obesity on ER+BCa. To assess whether obesity exerted adverse effects on BCa growth and whether vitamin D compounds could reduce these unfavorable effects, we employed a diet-induced obesity (DIO) model in ovariectomized C57BL/6 mice. Breast tumor cells originally from syngeneic Mmtv-Wnt1 transgenic mice were then implanted into the mammary fat pads of lean and obese mice. DIO accelerated the initiation and progression of the mammary tumors. Treatments with either calcitriol or dietary vitamin D reduced the adverse effects of obesity causing a delay in tumor appearance and inhibiting continued tumor growth. Beneficial actions of treatments with vitamin D or calcitriol on BCa and surrounding adipose tissue included repressed Esr1, aromatase, and Cox2 expression; decreased tumor-derived estrogen and PGE2; reduced expression of leptin receptors; and increased adiponectin receptors. We demonstrate that vitamin D treatments decreased insulin resistance, reduced leptin, and increased adiponectin signaling and also regulated the LKB1/AMPK pathway contributing to an overall decrease in local estrogen synthesis in the obese mice. We conclude that calcitriol and dietary vitamin D, acting by multiple interrelated pathways, mitigate obesity-enhanced BCa growth in a postmenopausal setting.

A synthetic lethal screen identifies the Vitamin D receptor as a novel gemcitabine sensitizer in pancreatic cancer cells

Overcoming chemoresistance of pancreatic cancer (PCa) cells should significantly extend patient survival. The current treatment modalities rely on a variety of DNA damaging agents including gemcitabine, FOLFIRINOX, and Abraxane that activate cell cycle checkpoints, which allows cells to survive these drug treaments. Indeed, these treatment regimens have only extended patient survival by a few months. The complex microenvironment of PCa tumors has been shown to complicate drug delivery thus decreasing the sensitivity of PCa tumors to chemotherapy. In this study, a genome-wide siRNA library was used to conduct a synthetic lethal screen of Panc1 cells that was treated with gemcitabine. A sublethal dose (50 nM) of the drug was used to model situations of limiting drug availability to PCa tumors in vivo. Twenty-seven validated sensitizer genes were identified from the screen including the Vitamin D receptor (VDR). Gemcitabine sensitivity was shown to be VDR dependent in multiple PCa cell lines in clonogenic survival assays. Sensitization was not achieved through checkpoint override but rather through disrupting DNA repair. VDR knockdown disrupted the cells' ability to form phospho-γH2AX and Rad51 foci in response to gemcitabine treatment. Disruption of Rad51 foci formation, which compromises homologous recombination, was consistent with increased sensitivity of PCa cells to the PARP inhibitor Rucaparib. Thus inhibition of VDR in PCa cells provides a new way to enhance the efficacy of genotoxic drugs.

Inhibition of Mouse Breast Tumor-Initiating Cells by Calcitriol and Dietary Vitamin D

The anticancer actions of vitamin D and its hormonally active form, calcitriol, have been extensively documented in clinical and preclinical studies. However, the mechanisms underlying these actions have not been completely elucidated. Here, we examined the effect of dietary vitamin D and calcitriol on mouse breast tumor-initiating cells (TICs, also known as cancer stem cells). We focused on MMTV-Wnt1 mammary tumors, for which markers for isolating TICs have previously been validated. We confirmed that these tumors expressed functional vitamin D receptors and estrogen receptors (ER) and exhibited calcitriol-induced molecular responses including ER downregulation. Following orthotopic implantation of MMTV-Wnt1 mammary tumor cells into mice, calcitriol injections or a vitamin D-supplemented diet caused a striking delay in tumor appearance and growth, whereas a vitamin D-deficient diet accelerated tumor appearance and growth. Calcitriol inhibited TIC tumor spheroid formation in a dose-dependent manner in primary cultures and inhibited TIC self-renewal in secondary passages. A combination of calcitriol and ionizing radiation inhibited spheroid formation more than either treatment alone. Further, calcitriol significantly decreased TIC frequency as evaluated by in vivo limiting dilution analyses. Calcitriol inhibition of TIC spheroid formation could be overcome by the overexpression of β-catenin, suggesting that the inhibition of Wnt/β-catenin pathway is an important mechanism mediating the TIC inhibitory activity of calcitriol in this tumor model. Our findings indicate that vitamin D compounds target breast TICs reducing tumor-initiating activity. Our data also suggest that combining vitamin D compounds with standard therapies may enhance anticancer activity and improve therapeutic outcomes.

Cdx2 polymorphism affects the activities of vitamin D receptor in human breast cancer cell lines and human breast carcinomas

Vitamin D plays a role in cancer development and acts through the vitamin D receptor (VDR). It regulates the action of hormone responsive genes and is involved in cell cycle regulation, differentiation and apoptosis. VDR is a critical component of the vitamin D pathway and different common single nucleotide polymorphisms have been identified. Cdx2 VDR polymorphism can play an important role in breast cancer, modulating the activity of VDR. The objective of this study is to assess the relationship between the Cdx2 VDR polymorphism and the activities of VDR in human breast cancer cell lines and carcinomas breast patients. Cdx2 VDR polymorphism and antiproliferative effects of vitamin D treatment were investigated in a panel of estrogen receptor-positive (MCF7 and T-47D) and estrogen receptor-negative (MDA-MB-231, SUM 159PT, SK-BR-3, BT549, MDA-MB-468, HCC1143, BT20 and HCC1954) human breast cancer cell lines. Furthermore, the potential relationship among Cdx2 VDR polymorphism and a number of biomarkers used in clinical management of breast cancer was assessed in an ad hoc set of breast cancer cases. Vitamin D treatment efficacy was found to be strongly dependent on the Cdx2 VDR status in ER-negative breast cancer cell lines tested. In our series of breast cancer cases, the results indicated that patients with variant homozygote AA were associated with bio-pathological characteristics typical of more aggressive tumours, such as ER negative, HER2 positive and G3. Our results may suggest a potential effect of Cdx2 VDR polymorphism on the efficacy of vitamin D treatment in aggressive breast cancer cells (estrogen receptor negative). These results suggest that Cdx2 polymorphism may be a potential biomarker for vitamin D treatment in breast cancer, independently of the VDR receptor expression.

Cooperation between BRCA1 and vitamin D is critical for histone acetylation of the p21waf1 promoter and growth inhibition of breast cancer cells and cancer stem-like cells

Carriers of germline mutations in the BRCA1 gene have a significant increased lifetime risk for being diagnosed with breast cancer. The incomplete penetrance of BRCA1 suggests that environmental and/or genetic factors modify the risk and incidence among mutation carriers. Nutrition and particular micronutrients play a central role in modifying the phenotypic expression of a given genotype by regulating chromatin structure and gene expression. The active form of vitamin D, 1α,25-dihydroxyvitamin D3, is a potent inhibitor of breast cancer growth. Here we report that two non-calcemic analogues of 1α,25-dihydroxyvitamin D3, seocalcitol (EB1089) and QW-1624F2-2, collaborate with BRCA1 in mediating growth inhibition of breast cancer cells and breast cancer stem-like cells. EB1089 induces a G1/S phase growth arrest that coincides with induction of p21waf1 expression only in BRCA1-expressing cells. A complete knockdown of BRCA1 or p21waf1 renders the cells unresponsive to EB1089. Furthermore, we show that in the presence of ligand, BRCA1 associates with vitamin D receptor (VDR) and the complex co-occupies vitamin D responsive elements (VDRE) at the CDKN1A (p21waf1) promoter and enhances acetylation of histone H3 and H4 at these sites. Thus, BRCA1 expression is critical for mediating the biological impact of vitamin D3 in breast tumor cells.

Improved clinical outcomes associated with vitamin D supplementation during adjuvant chemotherapy in patients with HER2+ nonmetastatic breast cancer

BACKGROUND

Vitamin D (VD) supplementation has pleiotropic effects that extend beyond their impact on bone health, including the disruption of downstream VD receptor signaling and human epidermal growth factor receptor 2 (HER2) signaling through the ErbB2/AKT/ERK pathway. In the present study, we examined our institutional experience with patients having nonmetastatic HER2-positive (HER(+)) breast cancer and hypothesized that those patients who received VD supplementation during neoadjuvant chemotherapy would have improved long-term outcomes.

PATIENTS AND METHODS

We performed a retrospective review of all patients (n = 308) given trastuzumab-based chemotherapy between 2006 and 2012 at the University of Miami/Sylvester Comprehensive Cancer Center (UM/SCCC). We identified 2 groups of patients for comparison-those who received VD supplementation during neoadjuvant chemotherapy (n = 134) and those who did not (n = 112). Univariate and multivariate Cox proportional hazard regression models were fitted to overall survival (OS) and disease-free survival (DFS).

RESULTS

More than half of the patients received VD during neoadjuvant chemotherapy (54.5%), with 60% receiving a dose < 10,000 units/wk and 33.3% having a VD deficiency at the start of therapy. In our final multivariate model, VD use was associated with improved DFS (hazard ratio [HR], 0.36; 95% confidence interval [CI], 0.15-0.88; P = .026], whereas larger tumor size was associated with worse DFS (HR, 3.52; 95% CI, 1.06-11.66; P = .04). There were no differences in OS based on any of the categories, including VD use, tumor size, number of metastatic lymph nodes, age at diagnosis, or lymphovascular invasion (LVI).

CONCLUSION

VD supplementation in patients with nonmetastatic HER2(+) breast cancer is associated with improved DFS.

1α,25-dihydroxyvitamin D3 inhibits cell growth and NFκB signaling in tamoxifen-resistant breast cancer cells

Resistance to antiestrogens is a major clinical problem in current breast cancer treatment and development of new treatment strategies for these tumors is highly prioritized. In this study, we have investigated the effects of 1α,25-dihydroxyvitamin D3 on the proliferation of tamoxifen-resistant cells. Further, we have investigated on a molecular level the effects of vitamin D on NFkB signaling in tamoxifen-resistant breast cancer cells. Parental human breast cancer MCF-7 cells and four tamoxifen-resistant sublines have been used to investigate the effects of 1α,25-dihydroxyvitamin D3 on cell proliferation using a colorimetric method, gene expression using quantitative PCR, protein phosphorylation using Western blot analysis and cellular localization of proteins using immunofluorescence microscopy. We found that 1α,25-dihydroxyvitamin D3 is able to strongly decrease the growth of both tamoxifen-sensitive and -resistant breast cancer cells and that this antiproliferative effect of 1α,25-dihydroxyvitamin D3 might be mediated via inhibition of the NFκB pathway. We found that 1α,25-dihydroxyvitamin D3 stimulates the gene expression of IkB, an NFκB-inhibiting protein, and that cells pretreated with 1α,25-dihydroxyvitamin D3 have a decreased sensitivity to TNFα stimulation. Further, we show that 1α,25-dihydroxyvitamin D3 treatment strongly decreases the TNFα-induced translocation of p65 into the nucleus. This manuscript reports novel findings regarding the effects of 1α,25-dihydroxyvitamin D3 on NFκB signaling in tamoxifen-resistant breast cancer cells and suggests that vitamin D might be interesting for further evaluation as a new strategy to treat antiestrogen-resistant breast cancers.

Pharmacological effects of vitamin D and its analogs: recent developments

Calcitriol, the hormonally active form of vitamin D, is well known for its diverse pharmacological activities, including modulation of cell growth, neuromuscular and immune function and reduction of inflammation. Calcitriol and its analogs exert potent effects on cellular differentiation and proliferation, regulate apoptosis and produce immunomodulatory effects. The purpose of this review is to provide information on various physiological and pharmacological activities of calcitriol and its newly discovered analogs. Special emphasis is given to skin diseases, cancer, diabetes and multiple sclerosis. A discussion is raised on the mechanisms of action of calcitriol and its analogs in various diseases, as well as on possible methods of delivery and targeting.

Vitamin D alters genes involved in follicular development and steroidogenesis in human cumulus granulosa cells

CONTEXT

Vitamin D deficiency is common among reproductive-aged women and has a role in female reproduction.

OBJECTIVE

This study evaluated the role of 1,25-dihydroxyvitamin D3 (vit D3) in ovarian follicular development and steroidogenesis by using a human granulosa cell (GC) model.

DESIGN, SETTING, AND PARTICIPANTS

Fifty-four women who underwent in vitro fertilization were enrolled.

INTERVENTION

Follicular fluid (FF) and mural and cumulus GCs were collected from small and large follicles. In separate experiments, primary cumulus GCs were cultured with or without vit D3 followed by RT-PCR for mRNA expression levels. The effect of recombinant anti-Mullerian hormone (AMH) on nuclear localization of phospho-Smad 1/5/8 was evaluated in the presence or absence of vit D3 by using immunofluorescence. 25-Hydroxyvitamin D levels in FF as well as cell culture media AMH, progesterone, and estradiol (E2) concentrations were determined by ELISA and RIA.

MAIN OUTCOME MEASURES

The following were measured: 1) mRNA expression levels; 2) 3β-hydroxysteroid dehydrogenase (3β-HSD) enzyme activity; 3) FSH-induced aromatase mRNA and E2 production; and 4) nuclear localization of phospho-Smad 1/5/8.

RESULTS

In a multivariate analysis, 25 OH-D levels in FF negatively correlated with AMH and AMH receptor (AMHR)-II mRNA levels in cumulus GCs of small follicles. Compared with women with replete 25-hydroxyvitamin D levels in FF, those with insufficient/deficient levels had a 2-fold increase in AMHR-II mRNA levels in cumulus GCs of small follicles (P = .02). Treatment with vit D3 caused a decrease in AMHR-II and FSH receptor mRNA but an increase in 3-βHSD mRNA levels compared with control (P < .05). Vit D3 enhanced 3-βHSD enzyme activity as assessed by increasing progesterone release; however, vit D3 did not affect FSH-induced aromatase mRNA and E2 production, but it decreased the phosphorylation of Smad 1/5/8 and its nuclear localization.

CONCLUSION

These data suggest that vit D3 alters AMH signaling and steroidogenesis in human cumulus GCs, possibly reflecting a state of GC luteinization potentiation.

Synthetic triterpenoid induces 15-PGDH expression and suppresses inflammation-driven colon carcinogenesis

Colitis-associated colon cancer (CAC) develops as a result of inflammation-induced epithelial transformation, which occurs in response to inflammatory cytokine-dependent downregulation of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) and subsequent suppression of prostaglandin metabolism. Agents that both enhance 15-PGDH expression and suppress cyclooxygenase-2 (COX-2) production may more effectively prevent CAC. Synthetic triterpenoids are a class of small molecules that suppress COX-2 as well as inflammatory cytokine signaling. Here, we found that administration of the synthetic triterpenoid 2-cyano-3,12-dioxooleana-1,9(11)-dien-C28-methyl ester (CDDO-Me) suppresses CAC in mice. In a spontaneous, inflammation-driven intestinal neoplasia model, deletion of Smad4 specifically in T cells led to progressive production of inflammatory cytokines, including TNF-α, IFN-γ, iNOS, IL-6, IL-1β; as well as activation of STAT1 and STAT3; along with suppression of 15-PGDH expression. Oral administration of CDDO-Me to mice with SMAD4-deficient T cells increased survival and suppressed intestinal epithelial neoplasia by decreasing production of inflammatory mediators and increasing expression of 15-PGDH. Induction of 15-PGDH by CDDO-Me was dose dependent in epithelial cells and was abrogated following treatment with TGF-β signaling inhibitors in vitro. Furthermore, CDDO-Me-dependent 15-PGDH induction was not observed in Smad3-/- mice. Similarly, CDDO-Me suppressed azoxymethane plus dextran sodium sulfate-induced carcinogenesis in wild-type animals, highlighting the potential of small molecules of the triterpenoid family as effective agents for the chemoprevention of CAC in humans.