The vitamin D analog, MART-10, represses metastasis potential via downregulation of epithelial-mesenchymal transition in pancreatic cancer cells

Vitamin D in Cancer Prevention and Treatment: A Review of Epidemiological, Preclinical, and Cellular Studies

BACKGROUND

Inhibition of human carcinomas has previously been linked to vitamin D due to its effects on cancer cell proliferation, migration, angiogenesis, and apoptosis induction. The anticancer activity of vitamin D has been confirmed by several studies, which have shown that increased cancer incidence is associated with decreased vitamin D and that dietary supplementation of vitamin D slows down the growth of xenografted tumors in mice. Vitamin D inhibits the growth of cancer cells by the induction of apoptosis as well as by arresting the cells at the G0/G1 (or) G2/M phase of the cell cycle. Aim and Key Scientific Concepts of the Review: The purpose of this article is to thoroughly review the existing information and discuss and debate to conclude whether vitamin D could be used as an agent to prevent/treat cancers. The existing empirical data have demonstrated that vitamin D can also work in the absence of vitamin D receptors (VDRs), indicating the presence of multiple mechanisms of action for this sunshine vitamin. Polymorphism in the VDR is known to play a key role in tumor cell metastasis and drug resistance. Although there is evidence that vitamin D has both therapeutic and cancer-preventive properties, numerous uncertainties and concerns regarding its use in cancer treatment still exist. These include (a) increased calcium levels in individuals receiving therapeutic doses of vitamin D to suppress the growth of cancer cells; (b) hyperglycemia induction in certain vitamin D-treated study participants; (c) a dearth of evidence showing preventive or therapeutic benefits of cancer in clinical trials; (d) very weak support from proof-of-principle studies; and (e) the inability of vitamin D alone to treat advanced cancers. Addressing these concerns, more potent and less toxic vitamin D analogs have been created, and these are presently undergoing clinical trial evaluation. To provide key information regarding the functions of vitamin D and VDRs, this review provided details of significant advancements in the functional analysis of vitamin D and its analogs and VDR polymorphisms associated with cancers.

The therapeutic potential of 1, 25-dihydroxy vitamin D3 on cisplatin-affected neurological functions is associated with the regulation of oxidative stress and inflammatory markers as well as levels of MMP2/9

Calcitriol as a biologically active form of vitamin D3 has beneficial effects on all body systems. This vitamin has a potent neuroprotective effect via several independent mechanisms against brain insults induced by anticancer drugs. The present study was designed to examine the neuroprotective effects of calcitriol against neurotoxicity induced by cisplatin. Induction of neurotoxicity was done with cisplatin administration (5 mg/kg/week) for 5 successive weeks in male Wistar rats. The neuroprotective influence of calcitriol supplementation (100ng/kg/day for 5 weeks) was assessed through behavioral, electrophysiological, and molecular experiments. Cisplatin administration impaired spatial learning and memory and decreased prefrontal brain-derived neurotrophic factor (BDNF). Peripheral sensory neuropathy was induced through cisplatin administration. Cisplatin also reduced the amplitudes of the compound action potential of sensory nerves in electrophysiological studies. Cisplatin treatment elevated MDA levels and reduced anti-oxidant (SOD and GPx) enzymes. Pro-inflammatory cytokines (IL-1β and TNF-α) and metalloproteinase-2 and 9 (MMP-2/9) were augmented through treatment with cisplatin. Learning and memory impairments along with BDNF changes caused by cisplatin were amended with calcitriol supplementation. Reduced sensory nerve conduction velocity in the cisplatin-treated group was improved by calcitriol. Calcitriol partially improved redox imbalance and diminished the pro-inflammatory cytokines and MMP-2/9 levels. Our findings showed that calcitriol supplementation can relieve cisplatin-induced peripheral neurotoxicity. Calcitriol can be regarded as a promising new neuroprotective agent.

What Dietary Patterns and Nutrients are Associated with Pancreatic Cancer? Literature Review

This narrative review summarizes the main findings of observational studies (case-control and cohort) as well as systematic reviews and meta-analyses on the role of nutrients and dietary patterns on pancreatic cancer (PC) risk and elucidates possible mechanisms for the association between nutrients or specific food components and the risk of PC. A literature search of MEDLINE (PubMed), Google Scholar, ScienceDirect, and Scopus was performed. An extensive search of related articles published in the English language from 1985 to 2022 was carried out. Our search included macro- and micronutrient intake as well as dietary patterns associated with PC. In conclusion, the consumption of a diet high in nutrients such as sugar, fats, and red and processed meats can increase the risk of PC. Conversely, a high dietary intake of fresh fruit and vegetables and their associated nutrients like fiber, antioxidants, and polyphenols may prevent PC. Dietary patterns loaded with red and processed meats were also linked to an increased risk of PC, whereas dietary patterns rich in plant-based foods like vegetables, fruits, whole grains, and legumes were associated with a reduced risk of PC. Dietary fiber, fat-soluble vitamins, water-soluble vitamins, and minerals might also play a protective role against PC.

Vitamin D and Cancer: An Historical Overview of the Epidemiology and Mechanisms

This is a narrative review of the evidence supporting vitamin D's anticancer actions. The first section reviews the findings from ecological studies of cancer with respect to indices of solar radiation, which found a reduced risk of incidence and mortality for approximately 23 types of cancer. Meta-analyses of observational studies reported the inverse correlations of serum 25-hydroxyvitamin D [25(OH)D] with the incidence of 12 types of cancer. Case-control studies with a 25(OH)D concentration measured near the time of cancer diagnosis are stronger than nested case-control and cohort studies as long follow-up times reduce the correlations due to changes in 25(OH)D with time. There is no evidence that undiagnosed cancer reduces 25(OH)D concentrations unless the cancer is at a very advanced stage. Meta-analyses of cancer incidence with respect to dietary intake have had limited success due to the low amount of vitamin D in most diets. An analysis of 25(OH)D-cancer incidence rates suggests that achieving 80 ng/mL vs. 10 ng/mL would reduce cancer incidence rates by 70 ± 10%. Clinical trials have provided limited support for the UVB-vitamin D-cancer hypothesis due to poor design and execution. In recent decades, many experimental studies in cultured cells and animal models have described a wide range of anticancer effects of vitamin D compounds. This paper will review studies showing the inhibition of tumor cell proliferation, dedifferentiation, and invasion together with the sensitization to proapoptotic agents. Moreover, 1,25-(OH)2D3 and other vitamin D receptor agonists modulate the biology of several types of stromal cells such as fibroblasts, endothelial and immune cells in a way that interferes the apparition of metastases. In sum, the available mechanistic data support the global protective action of vitamin D against several important types of cancer.

Pre-treatment serum vitamin D deficiency is associated with increased inflammatory biomarkers and short overall survival in patients with pancreatic cancer

BACKGROUND

Vitamin D deficiency and inflammation are associated with increased mortality. We investigated the relationship between pre-treatment serum vitamin D levels, inflammatory biomarkers (IL-6, YKL-40 and CRP) and overall survival (OS) in pancreatic ductal adenocarcinoma (PDAC) patients.

METHODS

Pre-treatment serum vitamin D, IL-6, YKL-40 and CRP levels were determined in 1,267 patients with PDAC enrolled from July 2008 to September 2018 in the prospective BIOPAC study (NCT03311776). The patients were grouped according to vitamin D levels: sufficient >50 nmol/L, insufficient 25-50 nmol/L and deficient <25 nmol/L.

RESULTS

Across all tumour stages, vitamin D-deficient patients had the highest median levels of IL-6 (8.3 pg/mL, range 0.7-91), YKL-40 (177 ng/ml, range 25-5279) and CRP (15.5 mg/L, range 0.8-384). The resected stage I and II patients with vitamin D deficiencies had a shorter median OS, 18.3 months (95% CI, 12.1-31.5 months) than those with sufficient levels, 29.7 months (95% CI, 22.3-36.1 months), and the hazard ratio for death was 1.55 (95% CI, 1.04-2.31; p = 0.03). In advanced PDAC, there was no significant difference in OS between the vitamin D groups.

CONCLUSIONS

Vitamin D deficiency was associated with increased inflammatory biomarkers in all PDAC stages. The resected stage I and II patients with sufficient vitamin D levels had a higher OS than those with a vitamin D deficiency. However, there was no correlation between vitamin D levels and survival in advanced PDAC. Future studies need to investigate vitamin D supplementation effects on survival in PDAC.

Knockdown of CYP24A1 Aggravates 1α,25(OH)2D3-Inhibited Migration and Invasion of Mouse Ovarian Epithelial Cells by Suppressing EMT

Epithelial-mesenchymal transition (EMT) bestows cancer cells with motile and invasive properties. But for ovarian tissues, EMT plays a physiological role in the postovulatory repair of ovary surface epithelial (OSE) cells. Accumulating data indicated that 1α,25(OH)₂D₃ decreased both the migration and invasion of various cancer cells by suppressing EMT. However, it remains unclear whether 1α,25(OH)₂D₃ inhibits the process of EMT during different stages of oncogenic transformation in mouse OSE (MOSE) cells. In present study, a spontaneous malignant transformation model of MOSE cells at three sequential stages (early, intermediate and late) was established in vitro first and then subjected to 1α,25(OH)₂D₃ treatment to investigate the effect of 1α,25(OH)₂D₃ on the oncogenic transformation of MOSE cells. We found that 1α,25(OH)₂D₃ significantly reduced the proliferation and invasion of late malignant transformed MOSE (M-L cells) cells by inhibiting EMT both in vitro and in vivo, but not in intermediate transformed (M-I) cells. Importantly, we found that the levels of CYP24A1 in M-I cells were dramatically higher than that in M-L cells following treatment with 1α,25(OH)₂D₃. Furthermore, we demonstrated that, in both M-I and M-L cells with CYP24A1 knockdown, 1α,25(OH)₂D₃ suppressed the proliferation and invasion, and reduced the expression of N-cadherin, Vimentin, β-catenin and Snail. In addition, knockdown of CYP24A1 suppressed EMT by increasing E-cadherin while decreasing N-cadherin, Vimentin, β-catenin and Snail. These findings provide support for inhibiting CYP24A1 as a potential approach to activate the vitamin D pathway in the prevention and therapy of ovarian cancer.

Low Plasmatic 25-hydroxyvitamin D at Diagnosis is Associated with Axillary Invasion, Chemoresistance and Metastasis in Women with Breast Cancer

PURPOSE

In this study, we investigated the circulating levels of 25-hydroxyvitamin D (25[OH]D) in Brazilian women with breast cancer in samples collected at diagnosis, and correlated these with clinicopathological parameters relevant to disease prognosis.

METHODS

This study involved 147 women diagnosed with infiltrative ductal carcinoma whose peripheral blood samples were collected, to have 25(OH)D levels measured in plasma.

RESULTS

Our findings indicated that circulating 25(OH)D levels at diagnosis were insufficient in patients with breast cancer. Further, 25(OH)D reduced plasmatic levels at diagnosis correlated significantly with poor prognosis parameters, including axillar positivity, chemoresistance and metastasis. Patients bearing triple-negative tumors also presented reduced 25(OH)D in plasma when compared to those who carried Luminal tumors. Our data suggest relevant correlations when 25(OH)D is reduced in plasma at diagnosis, such as advanced disease with axillar positivity, chemoresistance with advanced disease, early age at diagnosis with high histological grade and dead with axilla positivity.

CONCLUSIONS

Altogether, our findings reinforce that 25(OH)D reduction can be a plausible marker of disease prognosis in breast cancer.

Supramolecular Aggregation-Induced Emission Nanodots with Programmed Tumor Microenvironment Responsiveness for Image-Guided Orthotopic Pancreatic Cancer Therapy

Supramolecular nanomaterials as drug carriers have recently received increasing attention due to their intrinsic merits such as high stability, strong inclusion capability, and facile modification of the parental structure; however, intelligent ones with combined capacities of long blood circulation, highly efficient tumor cell uptake, and site-oriented drug release inside tumor cells are still rather limited. Herein, we report a strategy using supramolecular aggregation-induced emission (AIE) nanodots for image-guided drug delivery, which integrate both the advantages of AIE and supramolecular nanomaterials. The supramolecular AIE dots are prepared by the host-guest coassembly of the matrix metalloproteinase-2 (MMP-2) sensitive PEG-peptide (PEG₂₀₀₀-RRRRRRRR (R8)-PLGLAG-EKEKEKEKEKEK (EK6)) and functional α-cyclodextrins (α-CD) derivatives that are conjugated with the anticancer drug gemcitabine (GEM) and a far-red/near-infrared fluorescent rhodanine-3-acetic acid-based AIE luminogen, respectively. The supramolecular AIE dots realize long blood circulation time by virtue of the zwitterionic stealth peptide EK6. After largely accumulating in tumor tissues by the enhanced permeability and retention effect, the supramolecular AIE dots can successively respond to the tumor-overexpressed MMP-2 and intracellular reductive microenvironment, achieving both enhanced cancer cellular uptake and selective GEM release within cancer cells, which thus exhibit excellent tumor inhibition ability in both subcutaneous and orthotopic pancreatic tumor models.

MEX3A knockdown inhibits the development of pancreatic ductal adenocarcinoma

Background

Pancreatic ductal adenocarcinoma (PDA) is one of the most serious causes of death in the world due to its high mortality and inefficacy treatments. MEX3A was first identified in nematodes and was associated with tumor formation and may promote cell proliferation and tumor metastasis. So far, nothing is known about the relationship between MEX3A and PDA.

Methods

In this study, the expression level of MEX3A in PDA tissues was measured by immunohistochemistry. The qRT-PCR and western blot were used to identify the constructed MEX3A knockdown cell lines, which was further used to construct mouse xenotransplantation models. Cell proliferation, colony formation, cell apoptosis and migration were detected by MTT, colony formation, flow cytometry and Transwell.

Results

This study showed that MEX3A expression is significantly upregulated in PDA and associated with tumor grade. Loss-of-function studies showed that downregulation of MEX3A could inhibit cell growth in vitro and in vivo. Moreover, it was demonstrated that knockdown of MEX3A in PDA cells promotes apoptosis by regulating apoptosis-related factors, and inhibits migration through influencing EMT. At the same time, the regulation of PDA progression by MEX3A involves changes in downstream signaling pathways including Akt, p-Akt, PIK3CA, CDK6 and MAPK9.

Conclusions

We proposed that MEX3A is associated with the prognosis and progression of PDA,which can be used as a potential therapeutic target.

Redifferentiation therapeutic strategies in cancer

The widely recognized problems of pharmacological strategies based on killing cancer cells demand a rethink of therapeutic approaches. Tumor reversion strategies that aim to shift cancer cells to a healthy differentiated state are a promising alternative. Although many studies have firmly demonstrated the possibility of reverting cancer to a normal differentiated state, we are still unable (with the exception of retinoic acid in a form of leukemia) to revert cancer cells to a stable differentiated healthy state. Here, we review the main biological bases of redifferentiation strategies and provide a description of the most promising research avenues.

Calcitriol inhibits migration and invasion of renal cell carcinoma cells by suppressing Smad2/3-, STAT3- and β-catenin-mediated epithelial-mesenchymal transition

Low vitamin D status is associated with progression in patients with renal cell carcinoma (RCC). The present study found that vimentin, a mesenchymal marker, was accordingly upregulated, and E-cadherin, an epithelial marker, was downregulated in RCC patients with low vitamin D status. Thus, we investigated the effects of calcitriol or vitamin D3, an active form of vitamin D, on epithelial-mesenchymal transition (EMT) in RCC cells. RCC cells were treated by two models. In model 1, three RCC cell lines, ACHN, 786-O and CAKI-2, were incubated with either LPS (2.0 μg/mL) or transforming growth factor (TGF)-β1 (10 ng/mL) in the presence or absence of calcitriol (200 nmol/L). In model 2, two RCC cell lines, ACHN and CAKI-2, were incubated with calcitriol (200 nmol/L) only. Calcitriol inhibited migration and invasion not only in TGF-β1-stimulated but also in TGF-β1-unstimulated RCC cells. Moreover, calcitriol suppressed E-cadherin downregulation and vimentin upregulation not only in TGF-β1-stimulated but also in TGF-β1-unstimulated ACHN and CAKI-2 cells. Calcitriol attenuated LPS-induced upregulation of MMP-2, MMP-7, MMP-9, MMP-26 and urokinase-type plasminogen activator (u-PA) in ACHN cells. In addition, calcitriol blocked TGF-β1-induced nuclear translocation of ZEB1, Snail and Twist1 in ACHN and CAKI-2 cells. Mechanistically, calcitriol suppressed EMT through different signaling pathways: (i) calcitriol suppressed Smad2/3 phosphorylation by reinforcing physical interaction between vitamin D receptor (VDR) and Smad3 in TGF-β1-stimulated RCC cells; (ii) calcitriol inhibited signal transducer and activator of transcription (STAT)3 activation in LPS-stimulated RCC cells; (iii) calcitriol inhibited β-catenin/TCF-4 activation by promoting integration of VDR with β-catenin in TGF-β1-unstimulated RCC cells. Taken together, calcitriol inhibits migration and invasion of RCC cells partially by suppressing Smad2/3-, STAT3- and β-catenin-mediated EMT.

Vitamin D maintains E-cadherin intercellular junctions by downregulating MMP-9 production in human gingival keratinocytes treated by TNF-α

Purpose

Despite the well-known anti-inflammatory effects of vitamin D in periodontal health, its mechanism has not been fully elucidated. In the present study, the effect of vitamin D on strengthening E-cadherin junctions (ECJs) was explored in human gingival keratinocytes (HGKs). ECJs are the major type of intercellular junction within the junctional epithelium, where loose intercellular junctions develop and microbial invasion primarily occurs.

Methods

HOK-16B cells, an immortalized normal human gingival cell line, were used for the study. To mimic the inflammatory environment, cells were treated with tumor necrosis factor-alpha (TNF-α). Matrix metalloproteinases (MMPs) in the culture medium were assessed by an MMP antibody microarray and gelatin zymography. The expression of various molecules was investigated using western blotting. The extent of ECJ development was evaluated by comparing the average relative extent of the ECJs around the periphery of each cell after immunocytochemical E-cadherin staining. Vitamin D receptor (VDR) expression was examined via immunohistochemical analysis.

Results

TNF-α downregulated the development of the ECJs of the HGKs. Dissociation of the ECJs by TNF-α was accompanied by the upregulation of MMP-9 production and suppressed by a specific MMP-9 inhibitor, Bay 11-7082. Exogenous MMP-9 decreased the development of ECJs. Vitamin D reduced the production of MMP-9 and attenuated the breakdown of ECJs in the HGKs treated with TNF-α. In addition, vitamin D downregulated TNF-α-induced nuclear factor kappa B (NF-κB) signaling in the HGKs. VDR was expressed in the gingival epithelium, including the junctional epithelium.

Conclusions

These results suggest that vitamin D may avert TNF-α-induced downregulation of the development of ECJs in HGKs by decreasing the production of MMP-9, which was upregulated by TNF-α. Vitamin D may reinforce ECJs by downregulating NF-κB signaling, which is upregulated by TNF-α. Strengthening the epithelial barrier may be a way for vitamin D to protect the periodontium from bacterial invasion.

Small molecule inhibitors of epithelial-mesenchymal transition for the treatment of cancer and fibrosis

Tissue fibrosis and cancer both lead to high morbidity and mortality worldwide; thus, effective therapeutic strategies are urgently needed. Because drug resistance has been widely reported in fibrotic tissue and cancer, developing a strategy to discover novel targets for targeted drug intervention is necessary for the effective treatment of fibrosis and cancer. Although many factors lead to fibrosis and cancer, pathophysiological analysis has demonstrated that tissue fibrosis and cancer share a common process of epithelial-mesenchymal transition (EMT). EMT is associated with many mediators, including transcription factors (Snail, zinc-finger E-box-binding protein and signal transducer and activator of transcription 3), signaling pathways (transforming growth factor-β1, RAC-α serine/threonine-protein kinase, Wnt, nuclear factor-kappa B, peroxisome proliferator-activated receptor, Notch, and RAS), RNA-binding proteins (ESRP1 and ESRP2) and microRNAs. Therefore, drugs targeting EMT may be a promising therapy against both fibrosis and tumors. A large number of compounds that are synthesized or derived from natural products and their derivatives suppress the EMT by targeting these mediators in fibrosis and cancer. By targeting EMT, these compounds exhibited anticancer effects in multiple cancer types, and some of them also showed antifibrotic effects. Therefore, drugs targeting EMT not only have both antifibrotic and anticancer effects but also exert effective therapeutic effects on multiorgan fibrosis and cancer, which provides effective therapy against fibrosis and cancer. Taken together, the results highlighted in this review provide new concepts for discovering new antifibrotic and antitumor drugs.

The Extracellular Matrix and Pancreatic Cancer: A Complex Relationship

Pancreatic ductal adenocarcinoma (PDAC) has an extraordinarily dense fibrotic stroma that impedes tumor perfusion and delivery of anticancer drugs. Since the extracellular matrix (ECM) comprises the bulk of the stroma, it is primarily responsible for the increased interstitial tissue pressure and stiff mechanical properties of the stroma. Besides its mechanical influence, the ECM provides important biochemical and physical cues that promote survival, proliferation, and metastasis. By serving as a nutritional source, the ECM also enables PDAC cells to survive under the nutrient-poor conditions. While therapeutic strategies using stroma-depleting drugs have yielded disappointing results, an increasing body of research indicates the ECM may offer a variety of potential therapeutic targets. As preclinical studies of ECM-targeted drugs have shown promising effects, a number of clinical trials are currently investigating agents with the potential to advance the future treatment of PDAC. Thus, the present review seeks to give an overview of the complex relationship between the ECM and PDAC.

Vitamin D treatment abrogates the inflammatory response in paraquat-induced lung fibrosis

A high incidence of intentional or accidental paraquat (PQ) ingestion is related to irreversible lung fibrosis and no effective therapy is currently available. Vitamin D has emerged with promising results as an immunomodulatory molecule when abrogating the inflammatory responses of lung diseases. Therefore, we have investigated the role of vitamin D treatments on PQ-induced lung fibrosis in male C57/BL6 mice. Lung fibrosis was induced by a single injection of PQ (10 mg/kg; i.p.). The control group received PQ vehicle. Seven days later, after the PQ injection or the vehicle injection, the mice received vitamin D (5 μg/kg, i.p., once a day) or vehicle, for a further 7 days. Twenty-four hours after the last dose of vitamin D or the vehicle, the analysis were performed. The vitamin D treatments reduced the number of leukocytes in their BALF and they decreased the IL-6, IL-17, TGF-beta and MMP-9 levels and the abrogated collagenase deposits in their lung tissues. Conversely, the vitamin D treatments increased the resolvin D levels in their BALF. Moreover, their tracheal contractility was also significantly reduced by the vitamin D treatments. Altogether, the data that was obtained showed a promising use of vitamin D, in treating the lung fibrosis that had been induced by the PQ intoxications. This may improve its prognostic use for a non-invasive and low cost therapy.

Circulating concentrations of vitamin D in relation to pancreatic cancer risk in European populations

Evidence from in vivo, in vitro and ecological studies are suggestive of a protective effect of vitamin D against pancreatic cancer (PC). However, this has not been confirmed by analytical epidemiological studies. We aimed to examine the association between pre-diagnostic circulating vitamin D concentrations and PC incidence in European populations. We conducted a pooled nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC) and the Nord-Trøndelag Health Study's second survey (HUNT2) cohorts. In total, 738 primary incident PC cases (EPIC n = 626; HUNT2 n = 112; median follow-up = 6.9 years) were matched to 738 controls. Vitamin D [25(OH)D2 and 25(OH)D3 combined] concentrations were determined using isotope-dilution liquid chromatography-tandem mass spectrometry. Conditional logistic regression models with adjustments for body mass index and smoking habits were used to estimate incidence rate ratios (IRRs) and 95% confidence intervals (95%CI). Compared with a reference category of >50 to 75 nmol/L vitamin D, the IRRs (95% CIs) were 0.71 (0.42-1.20); 0.94 (0.72-1.22); 1.12 (0.82-1.53) and 1.26 (0.79-2.01) for clinically pre-defined categories of ≤25; >25 to 50; >75 to 100; and >100 nmol/L vitamin D, respectively (p for trend = 0.09). Corresponding analyses by quintiles of season-standardized vitamin D concentrations also did not reveal associations with PC risk (p for trend = 0.23). Although these findings among participants from the largest combination of European cohort studies to date show increasing effect estimates of PC risk with increasing pre-diagnostic concentrations of vitamin D, they are not statistically significant.

Vitamin D Receptor Signaling and Cancer

The vitamin D receptor (VDR) binds the secosteroid hormone 1,25(OH)₂D₃ with high affinity and regulates gene programs that control a serum calcium levels, as well as cell proliferation and differentiation. A significant focus has been to exploit the VDR in cancer settings. Although preclinical studies have been strongly encouraging, to date clinical trials have delivered equivocal findings that have paused the clinical translation of these compounds. However, it is entirely possible that mining of genomic data will help to refine precisely what are the key anticancer actions of vitamin D compounds and where these can be used most effectively.

A formulation of pancreatic pro-enzymes provides potent anti-tumour efficacy: a pilot study focused on pancreatic and ovarian cancer

Proteolytic enzymes have shown efficacy in cancer therapy. We present a combination of the two pro-enzymes Trypsinogen and Chymotrypsinogen A with potent in vitro and in vivo anti-tumour efficacy. A synergetic anti-tumour effect for Trypsinogen and Chymotrypsinogen A was determined at a ratio 1:6 (named PRP) using 24 human cancer cell lines. The antiangiogenic effect of PRP was analysed by matrigel-based tube formation and by fibrous capsule formation assays. Furthermore, cell invasion and wound healing assays together with qRT-PCR determination of epithelial-to-mesenchymal transition (EMT) markers were performed on human cancer cells treated with PRP. Additionally, in vivo pharmacokinetic studies were implemented and the PRP's anti-tumour efficacy was explored against orthotopic pancreatic and ovarian cancer tumours. PRP formulation was proven to inhibit in vitro angiogenesis, tumour growth, cancer cell migration and invasiveness; and to be an effective and well tolerated in vivo anti-tumour treatment. Finally, the clinical efficacy of a suppository formulation containing both pancreatic pro-enzymes in the context of a UK Pharmaceuticals Special Scheme was evaluated in advanced cancer patients. Consequently, PRP could have relevant oncological clinical applications for the treatment of advanced or metastatic pancreatic adenocarcinoma and advanced epithelial ovarian cancer.

Differential expression and androgen regulation of microRNAs and metalloprotease 13 in breast cancer cells

MicroRNA molecules (miRNAs) play important roles in regulating cell behavior. The expression of certain miRNAs has been shown to be regulated by the androgen receptor (AR), which seems to have a critical role in the tumorigenic process of breast cancer. The differential expression of 84 miRNAs was first examined in three breast cancer cell lines: the luminal MCF-7 and T47D cells and the molecular apocrine MDA-MB-453 cells. Analysis of basal expression of miRNAs revealed that each cell line had distinct miRNA expression where let-7a and -7b were markers of MDA-MB-453 cells, whereas miR-205 was a marker for the luminal cell lines. Treating the cells with the AR agonist, CI-4AS-1, resulted in unique alterations in the expression of specific miRNA among the three cell lines. Particularly, the expression of miR-100 and miR-125 was reduced in MDA-MB-453 cells by five and three folds, respectively. This effect was simultaneous with AR-induced increase in the expression and extracellular release of metalloprotease-13 (MMP13). Transfection of cells with either miR-100 or miR-125b negated the induction of MMP13 release. Additionally, AR activation induced a morphological alteration of MDA-MB-453 cells, which was blocked by miR-125b only. Collectively, these data indicate that AR may control the biological behavior of breast cancer cells and protein expression via miRNAs.

1,25D3 differentially suppresses bladder cancer cell migration and invasion through the induction of miR-101-3p

Metastasis is the major cause of bladder cancer death. 1,25D3, the active metabolite of vitamin D, has shown anti-metastasis activity in several cancer model systems. However, the role of 1,25D3 in migration and invasion in bladder cancer is unknown. To investigate whether 1,25D3 affects migration and invasion, four human bladder cell lines with different reported invasiveness were selected: low-invasive T24 and 253J cells and highly invasive 253J-BV and TCCSUP cells. All of the four bladder cancer cells express endogenous and inducible vitamin D receptor (VDR) as examined by immunoblot analysis. 1,25D3 had no effect on the proliferation of bladder cancer cells as assessed by MTT assay. In contrast, 1,25D3 suppressed migration and invasion in the more invasive 253J-BV and TCCSUP cells, but not in the low-invasive 253J and T24 cells using "wound" healing, chemotactic migration and Matrigel-based invasion assays. 1,25D3 promoted the expression of miR-101-3p and miR-126-3p in 253J-BV cells as examined by qRT-PCR. miR-101-3p inhibitor partially abrogated and pre-miR-101-3p further suppressed the inhibition of 1,25D3 on migration and invasion in 253J-BV cells. Further, 1,25D3 enhanced VDR recruitment to the promoter region of miR-101-3p using ChIP-qPCR assay. 1,25D3 enhanced the promoter activity of miR-101-3p as evaluated by luciferase reporter assay. Taken together, 1,25D3 suppresses bladder cancer cell migration and invasion in two invasive/migration competent lines but not in two less invasive/motile lines, which is partially through the induction of miR-101-3p expression at the transcriptional level.

The role of vitamin D and VDR in carcinogenesis: Through epidemiology and basic sciences

In the last two decades vitamin D (VD) research has demonstrated new extraskeletal actions of this pre-hormone, suggesting a protective role of this secosteroid in the onset, progression and prognosis of several chronic noncommunicable diseases, such as cardiovascular disease, diabetes mellitus or cancer. Regarding carcinogenesis, both preclinical and epidemiological evidence available show oncoprotective actions of VD and its receptor, the VDR. However, in late neoplastic stages the VD system (VDS) seems to be less functional, which appears to be due to an epigenetic silencing of the system. In preclinical experimental studies, VD presents oncoprotective actions through modulation of inflammation, cell proliferation, cell differentiation, angiogenesis, invasive and metastatic potential, apoptosis, miRNA expression regulation and modulation of the Hedgehog signalling pathway. Moreover, epidemiological evidence points towards an oncoprotective role of vitamin D and VDR in colorectal cancer. This association is more controversial with breast, ovarian and prostate cancers, although with a few adverse effects. Nonetheless, we should consider other factors to determine the benefit of increased serum concentration of VD. Much of the epidemiological evidence is still inconclusive, and we will have to wait for new, better-designed ongoing RCTs and their results to discern the real effect of vitamin D in cancer risk reduction and therapy. The objective of this literature review is to offer an up-to-date analysis of the role of the VD and VDR, in the onset, progression and prognosis of all types of cancer. We further discuss the available literature and suggest new hypotheses and future challenges in the field of VD research.

Vitamin D3 regulates LAMP3 expression in monocyte derived dendritic cells

The family of lysosome-associated membrane proteins (LAMPs) encompassing LAMP1, LAMP2 and DC-LAMP (LAMP3) are the major constituents of the glycoconjugates coat present on the inside of the lysosomal membrane. LAMP3 is highly expressed only in certain cell types and during the differentiation stages. Its expression is linked the maturation of dendritic cells, inflammation, poor prognosis of certain tumors, and the locus where it is encoded was identified as a risk factor for Parkinson's disease (PD). Here, we investigated the capacity of Vitamin D3 to modulate the expression of LAMP3 during the dendritic cells differentiation and maturation. Our results demonstrated that the Vitamin D3 reduce the LAMP3 mRNA/protein expression during the dendritic cells differentiation and maturation, via NFκB pathways. Furthermore, we demonstrated that the Vitamin D3 was able to modulate the expression of LAMP3 likewise to in vitro tolerogenic dendritic cells. In summary, these data showed that the decrease of LAMP3 expression by Vitamin D3could enhance the tolerogenic characteristic of dendritic cells.

1α,25-Dihydroxyvitamin D Inhibits the Metastatic Capability of MCF10CA1a and MDA-MB-231 Cells in an In Vitro Model of Breast to Bone Metastasis

Breast cancer metastasis to the bone continues to be a major health problem, with approximately 80% of advanced breast cancer patients expected to develop bone metastasis. Although the problem of bone metastasis persists, current treatment options for metastatic cancer patients are limited. In this study, we investigated the preventive role of the active vitamin D metabolite, 1α,25-dihydroxyvitamin D (1,25(OH)2D), against the metastatic potential of breast cancer cells using a novel three-dimensional model (rMET) recapitulating multiple steps of the bone metastatic process. Treatment of MCF10CA1a and MDA-MB-231 cells inhibited metastasis in the rMET model by 70% (±5.7%) and 21% (±6%), respectively. In addition, 1,25(OH)2D treatment decreased invasiveness (20 ± 11% of vehicle) and decreased the capability of MCF10CA1a cells to survive in the reconstructed bone environment after successful invasion through the basement membrane (69 ± 5% of vehicle). An essential step in metastasis is epithelial-mesenchymal transition (EMT). Treatment of MCF10CA1a cells with 1,25(OH)2D increased gene (2.04 ± 0.28-fold increase) and protein (1.87 ± 0.20-fold increase) expression of E-cadherin. Additionally, 1,25(OH)2D treatment decreased N-cadherin gene expression (42 ± 8% decrease), a marker for EMT. Collectively, the present study suggests that 1,25(OH)2D inhibits breast cancer cell metastatic capability as well as inhibits EMT, an essential step in the metastatic process.

1α,25(OH)₂D₃ Suppresses the Migration of Ovarian Cancer SKOV-3 Cells through the Inhibition of Epithelial-Mesenchymal Transition

Ovarian cancer is the most lethal gynecological malignancy due to its high metastatic ability. Epithelial-mesenchymal transition (EMT) is essential during both follicular rupture and epithelium regeneration. However, it may also accelerate the progression of ovarian carcinomas. Experimental studies have found that 1α,25-dihydroxyvitamin-D3 [1α,25(OH)₂D₃] can inhibit the proliferation of ovarian cancer cells. In this study, we investigated whether 1α,25(OH)₂D₃ could inhibit the migration of ovarian cancer cells via regulating EMT. We established a model of transient transforming growth factor-β1(TGF-β1)-induced EMT in human ovarian adenocarcinoma cell line SKOV-3 cells. Results showed that, compared with control, 1α,25(OH)₂D₃ not only inhibited the migration and the invasion of SKOV-3 cells, but also promoted the acquisition of an epithelial phenotype of SKOV-3 cells treated with TGF-β1. We discovered that 1α,25(OH)₂D₃ increased the expression of epithelial marker E-cadherin and decreased the level of mesenchymal marker, Vimentin, which was associated with the elevated expression of VDR. Moreover, 1α,25(OH)₂D₃ reduced the expression level of transcription factors of EMT, such as slug, snail, and β-catenin. These results indicate that 1α,25(OH)₂D₃ suppresses the migration and invasion of ovarian cancer cells by inhibiting EMT, implying that 1α,25(OH)₂D₃ might be a potential therapeutic agent for the treatment of ovarian cancer.

Environmental risk factors for pancreatic cancer: an update

Pancreatic cancer (PC) is one of the most aggressive diseases. Only 10 % of all PC cases are thought to be due to genetic factors. Here, we analyzed the most recently published case-control association studies, meta-analyses, and cohort studies with the aim to summarize the main environmental factors that could have a role in PC. Among the most dangerous agents involved in the initiation phase, there are the inhalation of cigarette smoke, and the exposure to mutagenic nitrosamines, organ-chlorinated compounds, heavy metals, and ionizing radiations. Moreover, pancreatitis, high doses of alcohol drinking, the body microbial infections, obesity, diabetes, gallstones and/or cholecystectomy, and the accumulation of asbestos fibers seem to play a crucial role in the progression of the disease. However, some of these agents act both as initiators and promoters in pancreatic acinar cells. Protective agents include dietary flavonoids, marine omega-3, vitamin D, fruit, vegetables, and the habit of regular physical activity. The identification of the factors involved in PC initiation and progression could be of help in establishing novel therapeutic approaches by targeting the molecular signaling pathways responsive to these stimuli. Moreover, the identification of these factors could facilitate the development of strategies for an early diagnosis or measures of risk reduction for high-risk people.

Commonalities in the Association between PPARG and Vitamin D Related with Obesity and Carcinogenesis

The PPAR nuclear receptor family has acquired great relevance in the last decade, which is formed by three different isoforms (PPARα, PPARβ/δ, and PPAR ϒ). Those nuclear receptors are members of the steroid receptor superfamily which take part in essential metabolic and life-sustaining actions. Specifically, PPARG has been implicated in the regulation of processes concerning metabolism, inflammation, atherosclerosis, cell differentiation, and proliferation. Thus, a considerable amount of literature has emerged in the last ten years linking PPARG signalling with metabolic conditions such as obesity and diabetes, cardiovascular disease, and, more recently, cancer. This review paper, at crossroads of basic sciences, preclinical, and clinical data, intends to analyse the last research concerning PPARG signalling in obesity and cancer. Afterwards, possible links between four interrelated actors will be established: PPARG, the vitamin D/VDR system, obesity, and cancer, opening up the door to further investigation and new hypothesis in this fascinating area of research.

MART-10, a newly synthesized vitamin D analog, represses metastatic potential of head and neck squamous carcinoma cells

Even with multidisciplinary treatment, the prognosis and quality of life of patients diagnosed with head and neck squamous cell carcinoma (HNSCC) are still not satisfactory. Previously, 19-Nor-2α-(3-hydroxypropyl)-1α,25(OH)₂D₃ (MART-10), the new brand 1α,25(OH)₂D₃ analog, has been demonstrated to be an effective drug to inhibit HNSCC growth in vitro. Since most cancer patients die of metastasis, in this study, the antimetastatic effect of MART-10 on HNSCC was investigated. Our results reveal that both 1α,25(OH)₂D₃ and MART-10 effectively repressed the migration and invasion of HNSCC cells, with MART-10 being much more potent than 1α,25(OH)₂D₃. The antimetastatic effect of 1α,25(OH)₂D₃ and MART-10 was mediated by attenuation of epithelial–mesenchymal transition (EMT), which was supported by the finding that the expression of EMT-inducing transcriptional factors, Sail and Twist, was inhibited by 1α,25(OH)₂D₃ and MART-10. The upregulation of E-cadherin and downregulation of N-cadherin in FaDu cells induced by both drugs further confirmed the repression of EMT. In addition, 1α,25(OH)₂D₃ and MART-10 treatment inhibited intracellular MMP-9 expression and extracellular MMP activity in FaDu cells. Collectively, our results suggest that the less-calcemia 1α,25(OH)₂D₃ analog, MART-10, is a promising drug for HNSCC treatment. Further clinical studies are warranted.

The role of vitamin D in cancer prevention

Vitamin D, also known as cholecalciferol, is the precursor to the active steroid hormone 1, 25-dihydroxyvitamin D3 (calcitriol; 1, 25(OH)2D3). The main physiological role for 1, 25(OH)2D3 is to regulate calcium and inorganic phosphate homeostasis for bone health. More recently, vitamin D has been investigated for its effects in the prevention and treatment of a variety of diseases such as cancer, autoimmune disorders, and cardiovascular disease. Preclinical data strongly support a role for vitamin D in the prevention of cancer through its anti-proliferative, pro-apoptotic, and anti-angiogenic effects on cells. Epidemiologic and clinical studies have shown mixed data on the correlation between serum vitamin D levels and cancer risk. This report seeks to outline results from the most recent preclinical and clinical studies investigating the potential role of vitamin D in cancer prevention.

Effect of vitamin D3 derivative MART-10 on cell growth and expression of survivin mRNA, c-myc protein and P21 protein in BxPC-3 cells

AIM: To analyze the effect of MART-10, a new kind of vitamin D₃ derivative, on cell growth and proliferation and the expression of survivin mRNA, c-myc protein and P21 protein in BxPC-3 cells.

METHODS: After BxPC-3 cells were treated with MART-10, the growth of BxPC-3 cells was assessed by MTT assay, cell cycle was analyzed by flow cytometry, survivin mRNA level was detected by reverse transcription-polymerase chain reaction (RT-PCR), and c-myc and P21 protein expression was detected by Western blot.

RESULTS: Treatment with MART-10 significantly inhibited the growth of BxPC-3 cells, and the IC₅₀ concentration was 10^-7 mmol/L. Flow cytometry results suggested that the proportion of S phase cells was decreased and the proportion of cells in G₀/G₁ phase was increased after treatment with MART-10. RT-PCR results showed that MART-10 significantly downregulated the mRNA level of survivin gene. Western blot results indicated that MART-10 significantly increased the protein levels of P21 but decreased the protein expression of c-myc.

CONCLUSION: Our results suggest that MART-10 can effectively inhibit the growth and proliferation of BxPC-3 cells, and the mechanism may be related with its influence on the expression of survivin, c-myc and P21.

The Vitamin D Analog, MART-10, Attenuates Triple Negative Breast Cancer Cells Metastatic Potential

Regarding breast cancer treatment, triple negative breast cancer (TNBC) is a difficult issue. Most TNBC patients die of cancer metastasis. Thus, to develop a new regimen to attenuate TNBC metastatic potential is urgently needed. MART-10 (19-nor-2α-(3-hydroxypropyl)-1α,25(OH)₂D₃), the newly-synthesized 1α,25(OH)₂D₃ analog, has been shown to be much more potent in cancer growth inhibition than 1α,25(OH)₂D₃ and be active in vivo without inducing obvious side effect. In this study, we demonstrated that both 1α,25(OH)₂D₃ and MART-10 could effectively repress TNBC cells migration and invasion with MART-10 more effective. MART-10 and 1α,25(OH)₂D₃ induced cadherin switching (upregulation of E-cadherin and downregulation of N-cadherin) and downregulated P-cadherin expression in MDA-MB-231 cells. The EMT(epithelial mesenchymal transition) process in MDA-MB-231 cells was repressed by MART-10 through inhibiting Zeb1, Zeb2, Slug, and Twist expression. LCN2, one kind of breast cancer metastasis stimulator, was also found for the first time to be repressed by 1α,25(OH)₂D₃ and MART-10 in breast cancer cells. Matrix metalloproteinase-9 (MMP-9) activity was also downregulated by MART-10. Furthermore, F-actin synthesis in MDA-MB-231 cells was attenuated as exposure to 1α,25(OH)₂D₃ and MART-10. Based on our result, we conclude that MART-10 could effectively inhibit TNBC cells metastatic potential and deserves further investigation as a new regimen to treat TNBC.

Vitamin D and the Epithelial to Mesenchymal Transition

Several studies support reciprocal regulation between the active vitamin D derivative 1α,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) and the epithelial to mesenchymal transition (EMT). Thus, 1,25(OH)₂D₃ inhibits EMT via the induction of a variety of target genes that encode cell adhesion and polarity proteins responsible for the epithelial phenotype and through the repression of key EMT inducers. Both direct and indirect regulatory mechanisms mediate these effects. Conversely, certain master EMT inducers inhibit 1,25(OH)₂D₃ action by repressing the transcription of VDR gene encoding the high affinity vitamin D receptor that mediates 1,25(OH)₂D₃ effects. Consequently, the balance between the strength of 1,25(OH)₂D₃ signaling and the induction of EMT defines the cellular phenotype in each context. Here we review the current understanding of the genes and mechanisms involved in the interplay between 1,25(OH)₂D₃ and EMT.

MART-10, the new brand of 1α,25(OH)2D3 analog, is a potent anti-angiogenic agent in vivo and in vitro

BACKGROUND

Angiogenesis is the hall marker for cancer growth and metastasis. Thus, anti-angiogenesis emerges as a new way to treat cancer. 1α,25(OH)2D3 is recently getting popular due to the non-mineral functions, which have been applied fore cancer treatment. The newly-synthesized 1α,25(OH)2D3 analog, MART-10, has been proved to be much more potent than 1α,25(OH)2D3 regarding inhibiting cancer cells growth and metastasis without inducing hypercalcemia in vivo. In this study, we aimed to investigate the effect of MART-10 and 1α,25(OH)2D3 on angiogenesis in vitro and in vivo.

METHODS AND RESULTS

MART-10 and 1α,25(OH)2D3 were able to repress VEGFA-induced human umbilical vein endothelial cells (HUVECs) migration, invasion and tube formation, but not proliferation, with MART-10 much more potent than 1α,25(OH)2D3. The Chick Chorioallantoic Membrane (CAM) assay and matrigeal angiogenesis assay further confirmed the in vivo more potent anti-angiogenesis effect of MART-10. MART-10 inhibited the VEGFA-induced HUVECs angiogenesis process through downregulation of Akt and Erk 1/2 phosphorylation. The VEGFA-VEGFR2 (VEGF receptor 2) axis is the main signal transducing pathway to stimulate angiogenesis. A positive autocrine manner was found for the first time in HUVECs as treated by VEGFA, which induced VEGFA expression and secretion, and VEGFR2 expression. MART-10 and 1α,25(OH)2D3 were demonstrated to be able to repress this positive autocrine manner, thus inhibiting angiogenesis.

CONCLUSIONS

MART-10 and 1α,25(OH)2D3 both are effective anti-angiogenesis agents. Given MART-10 is much more potent than 1α,25(OH)2D3 and active in vivo without obvious side effect, MART-10 should be deemed as a promising anti-cancer agent.

Vitamins in pancreatic cancer: a review of underlying mechanisms and future applications

Although there is increasing evidence that vitamins influence pancreatic adenocarcinoma biology and carcinogenesis, a comprehensive review is lacking. In this study, we performed a PubMed literature search to review the anticancer mechanisms and the preclinical and clinical studies that support the development of the bioactive vitamins A, C, D, E, and K in pancreatic cancer intervention. Preclinical studies have shown promising results for vitamin A in pancreatic cancer prevention, with clinical trials showing intriguing responses in combination with immunotherapy. For vitamin C, preclinical studies have shown slower tumor growth rates and/or increased survival when used alone or in combination with gemcitabine, with clinical trials with this combination revealing decreased primary tumor sizes and improved performance status. Preclinical studies with vitamin D analogues have shown potent antiproliferative effects and repression of migration and invasion of pancreatic cancer cells, with a clinical trial showing increased time to progression when calciferol was added to docetaxel. For vitamin E, preclinical studies have shown that δ-tocotrienol and γ-tocotrienol inhibited tumor cell growth and survival and augmented gemcitabine activity. Early-phase clinical trials with δ-tocotrienol are ongoing. Vitamin K demonstrates activation of apoptosis and inhibition of cellular growth in pancreatic tumor cells; however, there are no clinical studies available for further evaluation. Although preclinical and clinical studies are encouraging, randomized controlled trials with endpoints based on insights gained from mechanistic and preclinical studies and early-phase clinical trials are required to determine the efficacy of bioactive vitamin interventions in pancreatic cancer.

Polyphenols from marine brown algae target radiotherapy-coordinated EMT and stemness-maintenance in residual pancreatic cancer

INTRODUCTION

Therapy-associated onset of stemness-maintenance in surviving tumor-cells dictates tumor relapse/recurrence. Recently, we recognized the anti-pancreatic cancer (PC) potential of seaweed polyphenol manifolds and narrowed down three superior drug-deliverables that could serve as adjuvants and benefit PC cure. Utilizing the PC- cancer stem cells (PC-CSCs) grown ex vivo and mouse model of residual-PC, we investigated the benefits of seaweed polyphenols in regulating stemness-maintenance.

METHODS

ALDH(+)CD44(+)CD24(+) PC-CSCs from Panc-1, Panc-3.27, MiaPaCa-2, or BxPC-3 cells-derived xenografts grown ex vivo were either mock-irradiated, exposed to fractionated irradiation (FIR, 2Gy/D for 5 days), treated with polyphenols (100 μg/ml) of Hormophysa triquerta (HT-EA), Spatoglossum asperum (SA-EA) or Padina tetrastromatica (PT-EA) with/without FIR were examined for cell viability, transcription of 93 stem-cell-related molecules (QPCR profiling). Polyphenol-dependent regulation of FIR-transactivated Oct4, Zic3, EIF4C, Nanog, and LIF (QPCR) and functional translation of Nanog, SOX2, and OCT3/4 (immunoblotting) were examined in Panc-1/Panc-3.27/MiaPaCa-2/BxPC-3-xenografts derived PC-CSCs. Effect of seaweed-polyphenols in the regulation of EMT (N-Cadherin), pluripotency- (SOX2, OCT3/4, Nanog) and stemness-maintenance (PI3KR1, LIF, CD44) in therapy (FIR, 2Gy/D for 5D/wk for 3-weeks) resistant residual tumors were examined by tissue microarray construction and automated immunohistochemistry.

RESULTS

Ex vivo exposure of PC-CSCs to SA-EA, PT-EA and HT-EA exhibit dose-dependent inhibition of cell viability. FIR amplified the transcription of 69, 80, 74 and 77 stem-cell related genes in MiaPaCa-2-, Panc-1-, Panc-3.27- and BXPC3-established xenograft-derived ALDH(+)CD44(+)CD24(+)PC-CSCs. Treatment with SA-EA, PT-EA, or HT-EA completely suppressed FIR-activated stem-cell transcriptional machinery in ALDH(+)CD44(+)CD24(+)PC-CSCs established from MiaPaCa-2, Panc-1, Panc-3.27 and BXPC3 xenografts. QPCR validated EIF4C, OCT3/4, Nanog, LIF, and ZIC3 transcriptional profile outcomes. Nanog, Sox2, and OCT3/4 immunoblotting affirmed the PC-CSC radiosensitizing benefit of seaweed polyphenols. Residual-PC tissues microarrayed and immunostained after in vivo treatments recognized complete regulation of FIR-induced SOX2, OCT3/4, Nanog, LIF, CD44, PIK3R1, N-Cadherin, and E-Cadherin with SA-EA, PT-EA, and HT-EA.

CONCLUSIONS

These data, for the first time, documented the EMT/stemness-maintenance in therapy-resistant PC-CSCs. Further, the data suggest that seaweed polyphenols may inhibit PC relapse/recurrence by targeting therapy-orchestrated stem-cell signaling in residual cells.

MART-10, the vitamin D analog, is a potent drug to inhibit anaplastic thyroid cancer cell metastatic potential

The survival rate of anaplastic thyroid cancer (ATC) is still very poor due to its fast growth and high metastatic potential. Currently, no effective treatment is available. The active form of vitamin D3, 1α,25(OH)2D3, has been shown to have a anti-metastatic effect in pre-clinical studies, however induction of hypercalcemia hampered its clinical application. The new class of less-calcemic vitamin D analog, 19-nor-2α-(3-hydroxypropyl)-1α,25-dihydroxyvitamin D3 (MART-10), is much more potent than 1α,25(OH)2D3 to repress cancer growth and metastasis in a variety of cancers. In this study, we demonstrated that both 1α,25(OH)2D3 and MART-10 could effectively inhibit the migration and invasion of ATC cells, 8305C and 8505C, with MART-10 much more potent than 1α,25(OH)2D3. The anti-metastatic effect of 1α,25(OH)2D3 and MART-10 on ATC cells is mediated by reversal of cadherin switch (upregulation of E-cadherin and downregulation of N-cadherin), which led to the attenuation of EMT process, and decrease of F-actin formation. We further showed that the expressions of Slug, the EMT-related transcriptional factor, and MMP-9 were inhibited by 1α,25(OH)2D3 and MART-10 in 8505C cells, but not in 8303C cells. Since metastasis is the important cause of ATC-related death, our results strongly encourage the further in vivo study of MART-10 application against ATC.

Possible role of vitamin D3 on the adipocyte/fibroblast trans-differentiation mediated by pancreas cancer

In pancreatic tumors, white adipose tissue and metabolic disorders related to adipocytes, are recently reviewed as important co-factors in pancreas pathology. Cell differentiation in pancreatic cancer might involve therefore adipose tissue and factors released by adipocytes should play a fundamental role both in cancer onset and in its progression. Among these molecules, a great interest has been devoted quite recently to the hormonal role exerted by vitamin D3 in pancreatic cancer, particularly its active 1,25 dihydroxylated form. Despite the wide bulk of evidence reporting the chemopreventive role of vitamin D, the mechanism by which active vitamin D3 is able to counteract cancer progression and malignancy is yet far to be elucidated.