Plocabulin Displays Strong Cytotoxic Activity in a Personalized Colon Cancer Patient-Derived 3D Organoid Assay.

Plocabulin is a novel microtubule-disrupting antitumor agent of marine origin that is currently undergoing phase II clinical trials. Plocabulin has potent antiproliferative and antiangiogenic actions in carcinoma cell lines and has antitumor activity in xenografted mice. Here, we used three-dimensional (3D) tumor organoids derived from three colorectal cancer (CRC) patients to study the effect of plocabulin in a personalized assay system that ensures dose dependence and high reproducibility. The cytotoxicity of plocabulin was an order of magnitude higher than that of the active irinotecan derivative SN38 (7-ethyl-10-hydroxy-camptothecin) in tumor organoids at different passages. Moreover, plocabulin maintained its strong cytotoxic activity in wash-out experiments, in which a short pulse treatment of tumor organoids was as efficient as continuous treatment. Our data show that plocabulin has a very potent cytotoxic action in CRC patient-derived tumor organoids, supporting ongoing clinical trials with plocabulin and the use of organoid assays to provide personalized validation of antitumor drugs.

Vitamin D receptor expression and associated gene signature in tumour stromal fibroblasts predict clinical outcome in colorectal cancer.

OBJECTIVE: Colorectal cancer (CRC) is a major health concern. Vitamin D deficiency is associated with high CRC incidence and mortality, suggesting a protective effect of vitamin D against this disease. Given the strong influence of tumour stroma on cancer progression, we investigated the potential effects of the active vitamin D metabolite 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) on CRC stroma. DESIGN: Expression of vitamin D receptor (VDR) and two 1,25(OH)2D3 target genes was analysed in 658 patients with CRC with prolonged clinical follow-up. 1,25(OH)2D3 effects on primary cultures of patient-derived colon normal fibroblasts (NFs) and cancer-associated fibroblasts (CAFs) were studied using collagen gel contraction and migration assays and global gene expression analyses. Publicly available data sets (n=877) were used to correlate the 1,25(OH)2D3-associated gene signature in CAFs with CRC outcome. RESULTS: High VDR expression in tumour stromal fibroblasts was associated with better overall survival (OS) and progression-free survival in CRC, independently of its expression in carcinoma cells. 1,25(OH)2D3 inhibited the protumoural activation of NFs and CAFs and imposed in CAFs a 1,25(OH)2D3-associated gene signature that correlated with longer OS and disease-free survival in CRC. Furthermore, expression of two genes from the signature, CD82 and S100A4, correlated with stromal VDR expression and clinical outcome in our cohort of patients with CRC. CONCLUSIONS: 1,25(OH)2D3 has protective effects against CRC through the regulation of stromal fibroblasts. Accordingly, expression of VDR and 1,25(OH)2D3-associated gene signature in stromal fibroblasts predicts a favourable clinical outcome in CRC. Therefore, treatment of patients with CRC with VDR agonists could be explored even in the absence of VDR expression in carcinoma cells.

Vitamin D opposes multilineage cell differentiation induced by Notch inhibition and BMP4 pathway activation in human colon organoids.

Understanding the mechanisms involved in colonic epithelial differentiation is key to unraveling the alterations causing inflammatory conditions and cancer. Organoid cultures provide an unique tool to address these questions but studies are scarce. We report a differentiation system toward enterocytes and goblet cells, the two major colonic epithelial cell lineages, using colon organoids generated from healthy tissue of colorectal cancer patients. Culture of these organoids in medium lacking stemness agents resulted in a modest ultrastructural differentiation phenotype with low-level expression of enterocyte (KLF4, KRT20, CA1, FABP2) and goblet cell (TFF2, TFF3, AGR2) lineage markers. BMP pathway activation through depletion of Noggin and addition of BMP4 resulted in enterocyte-biased differentiation. Contrarily, blockade of the Notch pathway using the γ-secretase inhibitor dibenzazepine (DBZ) favored goblet cell differentiation. Combination treatment with BMP4 and DBZ caused a balanced strong induction of both lineages. In contrast, colon tumor organoids responded poorly to BMP4 showing only weak signals of cell differentiation, and were unresponsive to DBZ. We also investigated the effects of 1α,25-dihydroxyvitamin D3 (calcitriol) on differentiation. Calcitriol attenuated the effects of BMP4 and DBZ on colon normal organoids, with reduced expression of differentiation genes and phenotype. Consistently, in normal organoids, calcitriol inhibited early signaling by BMP4 as assessed by reduction of the level of phospho-SMAD1/5/8. Our results show that BMP and Notch signaling play key roles in human colon stem cell differentiation to the enterocytic and goblet cell lineages and that calcitriol modulates these processes favoring stemness features.

KDM6B/JMJD3 histone demethylase is induced by vitamin D and modulates its effects in colon cancer cells.

KDM6B/JMJD3 is a histone H3 lysine demethylase with an important gene regulatory role in development and physiology. Here, we show that human JMJD3 expression is induced by the active vitamin D metabolite 1α,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) and that JMJD3 modulates the gene regulatory action of this hormone. 1,25(OH)(2)D(3) activates the JMJD3 gene promoter and increases the level of JMJD3 RNA in human cancer cells. JMJD3 upregulation was strictly dependent on vitamin D receptor (VDR) expression and was abolished by cycloheximide. In SW480-ADH colon cancer cells, JMJD3 knockdown or expression of an inactive mutant JMJD3 fragment decreased the induction by 1,25(OH)(2)D(3) of several target genes and of an epithelial adhesive phenotype. Moreover, JMJD3 knockdown upregulated the epithelial-to-mesenchymal transition inducers SNAIL1 and ZEB1 and the mesenchymal markers fibronectin and LEF1, while it downregulated the epithelial proteins E-cadherin, Claudin-1 and Claudin-7. Additionally, JMJD3 knockdown abolished the nuclear export of ß-catenin and the inhibition of ß-catenin transcriptional activity caused by 1,25(OH)(2)D(3). Importantly, the expression of JMJD3 correlated directly with that of VDR and inversely with that of SNAI1 in a series of 96 human colon tumours. Our results indicate for the first time that an epigenetic gene coding for a histone demethylase such as JMJD3 is a VDR co-target that partially mediates the effects of 1,25(OH)(2)D(3) on human colon.

From molecular basis to clinical insights: a challenging future for the vitamin D endocrine system in colorectal cancer.

Colorectal cancer (CRC) is one of the most life-threatening neoplasias in terms of incidence and mortality worldwide. Vitamin D deficiency has been associated with an increased risk of CRC. 1α,25-Dihydroxyvitamin D3 [1,25(OH)2 D3 ], the most active vitamin D metabolite, is a pleiotropic hormone that, through its binding to a transcription factor of the nuclear receptor superfamily, is a major regulator of the human genome. 1,25(OH)2 D3 acts on colon carcinoma and stromal cells and displays tumor protective actions. Here, we review the variety of molecular mechanisms underlying the effects of 1,25(OH)2 D3 in CRC, which affect multiple processes that are dysregulated during tumor initiation and progression. Additionally, we discuss the epidemiological data that associate vitamin D deficiency and CRC, and the most relevant randomized controlled trials of vitamin D3 supplementation conducted in both healthy individuals and CRC patients.

Tailored chemotherapy for colorectal cancer peritoneal metastases based on a drug-screening platform in patient-derived organoids: a case report.

Background: Peritoneal metastasis from colorectal cancer (CRC) has limited therapeutic options and poor prognosis. Systemic chemotherapy combined with cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) or pressurized intraperitoneal aerosol chemotherapy (PIPAC) have yielded initial promising results. However, standard local therapies with oxaliplatin and mitomycin are not optimal and a better individualized management of these patients remains as an unmet clinical need. Patient-derived organoid (PDO) technology allows to culture in three dimensions normal and cancer stem cells (CSC) that self-organize in multicellular structures that recapitulates some of the features of the particular organ or tumor of origin, emerging as a promising tool for drug-testing and precision medicine. This technology could improve the efficacy of systemic and intraperitoneal chemotherapy and avoid unnecessary treatments and side effects to the patient. Case Description: Here we report a case of a 45-year-old man with a rectal adenocarcinoma with liver, lymph node and peritoneal metastases. The patient was treated with systemic chemotherapy (FOLFOXIRI plus Bevacizumab) and was subjected to mitomycin-based PIPAC. We generated patient-derived peritoneal carcinomatosis organoids in order to screen the activity of drugs for a personalized treatment. Both 5-FU and SN-38, the active irinotecan derivative, displayed strong cytotoxicity, while the response to oxaliplatin was much lower. Although the development of a colo-cutaneous fistulae prevented from further PIPAC, the patient continued with fluoropirimidine maintenance treatment based on standard clinical practice and the drug-screening test performed on organoids. Conclusions: Our results suggest that the peritoneal implant shows chemoresistance to oxaliplatin, while it might still be sensitive to irinotecan and 5-FU, which supports a potential benefit of these two drugs in the local and/or systemic treatment of our patient. This study shows the strength of the utility of the establishment of organoids for drug response assays and thus, for the personalized treatment of colorectal carcinomatosis patients.

An amino acid transporter subunit as an antibody-drug conjugate target in colorectal cancer.

BACKGROUND: Advanced colorectal cancer (CRC) is difficult to treat. For that reason, the development of novel therapeutics is necessary. Here we describe a potentially actionable plasma membrane target, the amino acid transporter protein subunit CD98hc. METHODS: Western blot and immunohistochemical analyses of CD98hc protein expression were carried out on paired normal and tumoral tissues from patients with CRC. Immunofluorescence and western studies were used to characterize the action of a DM1-based CD98hc-directed antibody-drug conjugate (ADC). MTT and Annexin V studies were performed to evaluate the effect of the anti-CD98hc-ADC on cell proliferation and apoptosis. CRISPR/Cas9 and shRNA were used to explore the specificity of the ADC. In vitro analyses of the antitumoral activity of the anti-CD98hc-ADC on 3D patient-derived normal as well as tumoral organoids were also carried out. Xenografted CRC cells and a PDX were used to analyze the antitumoral properties of the anti-CD98hc-ADC. RESULTS: Genomic as well proteomic analyses of paired normal and tumoral samples showed that CD98hc expression was significantly higher in tumoral tissues as compared to levels of CD98hc present in the normal colonic tissue. In human CRC cell lines, an ADC that recognized the CD98hc ectodomain, reached the lysosomes and exerted potent antitumoral activity. The specificity of the CD98hc-directed ADC was demonstrated using CRC cells in which CD98hc was decreased by shRNA or deleted using CRISPR/Cas9. Studies in patient-derived organoids verified the antitumoral action of the anti-CD98hc-ADC, which largely spared normal tissue-derived colon organoids. In vivo studies using xenografted CRC cells or patient-derived xenografts confirmed the antitumoral activity of the anti-CD98hc-ADC. CONCLUSIONS: The studies herewith reported indicate that CD98hc may represent a novel ADC target that, upon well-designed clinical trials, could be used to increase the therapeutic armamentarium against CRC.

Vitamin D induces SIRT1 activation through K610 deacetylation in colon cancer.

Posttranslational modifications of epigenetic modifiers provide a flexible and timely mechanism for rapid adaptations to the dynamic environment of cancer cells. SIRT1 is an NAD+-dependent epigenetic modifier whose activity is classically associated with healthy aging and longevity, but its function in cancer is not well understood. Here, we reveal that 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3, calcitriol), the active metabolite of vitamin D (VD), promotes SIRT1 activation through auto-deacetylation in human colon carcinoma cells, and identify lysine 610 as an essential driver of SIRT1 activity. Remarkably, our data show that the post-translational control of SIRT1 activity mediates the antiproliferative action of 1,25(OH)2D3. This effect is reproduced by the SIRT1 activator SRT1720, suggesting that SIRT1 activators may offer new therapeutic possibilities for colon cancer patients who are VD deficient or unresponsive. Moreover, this might be extrapolated to inflammation and other VD deficiency-associated and highly prevalent diseases in which SIRT1 plays a prominent role.

PKD phosphorylation and COP9/Signalosome modulate intracellular Spry2 protein stability.

Spry2 is a molecular modulator of tyrosine kinase receptor signaling pathways that has cancer-type-specific effects. Mammalian Spry2 protein undergoes tyrosine and serine phosphorylation in response to growth factor stimulation. Spry2 expression is distinctly altered in various cancer types. Inhibition of the proteasome functionality results in reduced intracellular Spry2 degradation. Using in vitro and in vivo assays, we show that protein kinase D (PKD) phosphorylates Spry2 at serine 112 and interacts in vivo with the C-terminal half of this protein. Importantly, missense mutation of Ser112 decreases the rate of Spry2 intracellular protein degradation. Either knocking down the expression of all three mammalian PKD isoforms or blocking their kinase activity with a specific inhibitor contributes to the stabilization of Spry2 wild-type protein. Downregulation of CSN3, a component of the COP9/Signalosome that binds PKD, significantly increases the half-life of Spry2 wild-type protein but does not affect the stability of a Spry2 after mutating Ser112 to the non-phosphorylatable residue alanine. Our data demonstrate that both PKD and the COP9/Signalosome play a significant role in control of Spry2 intracellular stability and support the consideration of the PKD/COP9 complex as a potential therapeutic target in tumors where Spry2 expression is reduced.

Clinico-Pathological Features, Outcomes and Impacts of COVID-19 Pandemic on Patients with Early-Onset Colorectal Cancer: A Single-Institution Experience.

BACKGROUND: The rising incidence of colorectal cancer (CRC) among young patients is alarming. We aim to characterize the clinico-pathological features and outcomes of patients with early-onset CRC (EOCRC), as well as the impacts of COVID-19 pandemic. METHODS: We included all patients with pathologically confirmed diagnoses of CRC at Hospital Universitario La Paz from October 2016 to December 2021. The EOCRC cut-off age was 50 years old. RESULTS: A total of 1475 patients diagnosed with CRC were included, eighty (5.4%) of whom had EOCRC. Significant differences were found between EOCRC and later-onset patients regarding T, N stage and metastatic presentation at diagnosis; perineural invasion; tumor budding; high-grade tumors; and signet ring cell histology, with all issues having higher prevalence in the early-onset group. More EOCRC patients had the RAS/ BRAF wild type. Chemotherapy was administered more frequently to patients with EOCRC. In the metastatic setting, the EOCRC group presented a significantly longer median OS. Regarding the COVID-19 pandemic, more patients with COVID-19 were diagnosed with metastatic disease (61%) in the year after the lockdown (14 March 2020) than in the pre-pandemic EOCRC group (29%). CONCLUSIONS: EOCRC is diagnosed at a more advanced stage and with worse survival features in localized patients. More patients with EOCRC were diagnosed with metastatic disease in the year after the COVID-19 pandemic lockdown. The long-term consequences of COVID-19 are yet to be determined.

p53 wild-type colorectal cancer cells that express a fetal gene signature are associated with metastasis and poor prognosis.

Current therapy against colorectal cancer (CRC) is based on DNA-damaging agents that remain ineffective in a proportion of patients. Whether and how non-curative DNA damage-based treatment affects tumor cell behavior and patient outcome is primarily unstudied. Using CRC patient-derived organoids (PDO)s, we show that sublethal doses of chemotherapy (CT) does not select previously resistant tumor populations but induces a quiescent state specifically to TP53 wildtype (WT) cancer cells, which is linked to the acquisition of a YAP1-dependent fetal phenotype. Cells displaying this phenotype exhibit high tumor-initiating and metastatic activity. Nuclear YAP1 and fetal traits are present in a proportion of tumors at diagnosis and predict poor prognosis in patients carrying TP53 WT CRC tumors. We provide data indicating the higher efficacy of CT together with YAP1 inhibitors for eradication of therapy resistant TP53 WT cancer cells. Together these results identify fetal conversion as a useful biomarker for patient prognosis and therapy prescription.

Organoids and Colorectal Cancer.

Organoids were first established as a three-dimensional cell culture system from mouse small intestine. Subsequent development has made organoids a key system to study many human physiological and pathological processes that affect a variety of tissues and organs. In particular, organoids are becoming very useful tools to dissect colorectal cancer (CRC) by allowing the circumvention of classical problems and limitations, such as the impossibility of long-term culture of normal intestinal epithelial cells and the lack of good animal models for CRC. In this review, we describe the features and current knowledge of intestinal organoids and how they are largely contributing to our better understanding of intestinal cell biology and CRC genetics. Moreover, recent data show that organoids are appropriate systems for antitumoral drug testing and for the personalized treatment of CRC patients.

Vitamin D Effects on Cell Differentiation and Stemness in Cancer.

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

Comparative Study of Organoids from Patient-Derived Normal and Tumor Colon and Rectal Tissue.

Colon and rectal tumors, often referred to as colorectal cancer, show different gene expression patterns in studies that analyze whole tissue biopsies containing a mix of tumor and non-tumor cells. To better characterize colon and rectal tumors, we investigated the gene expression profile of organoids generated from endoscopic biopsies of rectal tumors and adjacent normal colon and rectum mucosa from therapy-naive rectal cancer patients. We also studied the effect of vitamin D on these organoid types. Gene profiling was performed by RNA-sequencing. Organoids from a normal colon and rectum had a shared gene expression profile that profoundly differed from that of rectal tumor organoids. We identified a group of genes of the biosynthetic machinery as rectal tumor organoid-specific, including those encoding the RNA polymerase II subunits POLR2H and POLR2J. The active vitamin D metabolite 1α,25-dihydroxyvitamin D3/calcitriol upregulated stemness-related genes (LGR5, LRIG1, SMOC2, and MSI1) in normal rectum organoids, while it downregulated differentiation marker genes (TFF2 and MUC2). Normal colon and rectum organoids share similar gene expression patterns and respond similarly to calcitriol. Rectal tumor organoids display distinct and heterogeneous gene expression profiles, with differences with respect to those of colon tumor organoids, and respond differently to calcitriol than normal rectum organoids.

Vitamin D differentially regulates colon stem cells in patient-derived normal and tumor organoids.

Intestine is a major target of vitamin D and several studies indicate an association between vitamin D deficiency and inflammatory bowel diseases (IBD), but also increased colorectal cancer (CRC) risk and mortality. However, the putative effects of 1α,25-dihydroxyvitamin D3 (calcitriol), the active vitamin D metabolite, on human colonic stem cells are unknown. Here we show by immunohistochemistry and RNAscope in situ hybridization that vitamin D receptor (VDR) is unexpectedly expressed in LGR5+ colon stem cells in human tissue and in normal and tumor organoid cultures generated from patient biopsies. Interestingly, normal and tumor organoids respond differentially to calcitriol with profound and contrasting changes in their transcriptomic profiles. In normal organoids, calcitriol upregulates stemness-related genes, such as LGR5, SMOC2, LRIG1, MSI1, PTK7, and MEX3A, and inhibits cell proliferation. In contrast, in tumor organoids calcitriol has little effect on stemness-related genes while it induces a differentiated phenotype, and variably reduces cell proliferation. Concordantly, electron microscopy showed that calcitriol does not affect the blastic undifferentiated cell phenotype in normal organoids but it induces a series of differentiated features in tumor organoids. Our results constitute the first demonstration of a regulatory role of vitamin D on human colon stem cells, indicating a homeostatic effect on colon epithelium with relevant implications in IBD and CRC.

Urothelial organoids originating from Cd49fhigh mouse stem cells display Notch-dependent differentiation capacity.

Understanding urothelial stem cell biology and differentiation has been limited by the lack of methods for their unlimited propagation. Here, we establish mouse urothelial organoids that can be maintained uninterruptedly for >1 year. Organoid growth is dependent on EGF and Wnt activators. High CD49f/ITGA6 expression features a subpopulation of organoid-forming cells expressing basal markers. Upon differentiation, multilayered organoids undergo reduced proliferation, decreased cell layer number, urothelial program activation, and acquisition of barrier function. Pharmacological modulation of PPARγ and EGFR promotes differentiation. RNA sequencing highlighted genesets enriched in proliferative organoids (i.e. ribosome) and transcriptional networks involved in differentiation, including expression of Wnt ligands and Notch components. Single-cell RNA sequencing (scRNA-Seq) analysis of the organoids revealed five clusters with distinct gene expression profiles. Together, with the use of γ-secretase inhibitors and scRNA-Seq, confirms that Notch signaling is required for differentiation. Urothelial organoids provide a powerful tool to study cell regeneration and differentiation.

The endocrine vitamin D system in the gut.

The active vitamin D metabolite 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) has important regulatory actions in the gut through endocrine and probably also intracrine, autocrine and paracrine mechanisms. By activating the vitamin D receptor (VDR), which is expressed at a high level in the small intestine and colon, 1,25(OH)2D3 regulates numerous genes that control gut physiology and homeostasis. 1,25(OH)2D3 is a major responsible for epithelial barrier function and calcium and phosphate absorption, and the host's defense against pathogens and the inflammatory response by several types of secretory and immune cells. Moreover, recent data suggest that 1,25(OH)2D3 has a regulatory effect on the gut microbiota and stromal fibroblasts. Many studies have linked vitamin D deficiency to inflammatory bowel diseases (ulcerative colitis and Crohn's disease) and to an increased risk of colorectal cancer, and the possible use of VDR agonists to prevent or treat these diseases is receiving increasing interest.

Vitamin D Is a Multilevel Repressor of Wnt/b-Catenin Signaling in Cancer Cells.

The Wnt/b-catenin signaling pathway is abnormally activated in most colorectal cancers and in a proportion of other neoplasias. This activation initiates or contributes to carcinogenesis by regulating the expression of a large number of genes in tumor cells. The active vitamin D metabolite 1a,25-dihydroxyvitamin D3 (1,25(OH)2D3) inhibits Wnt/b-catenin signaling by several mechanisms at different points along the pathway. Additionally, paracrine actions of 1,25(OH)2D3 on stromal cells may also repress this pathway in neighbouring tumor cells. Here we review the molecular basis for the various mechanisms by which 1,25(OH)2D3 antagonizes Wnt/b-catenin signaling, preferentially in human colon carcinoma cells, and the consequences of this inhibition for the phenotype and proliferation rate. The effect of the vitamin D system on Wnt/b-catenin signaling and tumor growth in animal models will also be commented in detail. Finally, we revise existing data on the relation between vitamin D receptor expression and vitamin D status and the expression of Wnt/b-catenin pathway genes and targets in cancer patients.

Vitamin D has wide regulatory effects on histone demethylase genes.

Vitamin D from the diet or synthesized in the skin upon UV-B irradiation is converted in the organism into the active metabolite 1α,25- dihydroxyvitamin D 3 [1,25(OH) 2D 3, calcitriol], a pleiotropic hormone with wide regulatory actions. The classical model of 1,25(OH)2D3 action implies the activation of the vitamin D receptor, which binds specific DNA sequences in its target genes and modulates their transcription rate. We have recently shown that 1,25(OH) 2D 3 induces the expression of the JMJD3 gene coding for a histone demethylase that is involved in epigenetic regulation. JMJD3 mediates the effects of 1,25(OH) 2D 3 on a subset of target genes and affects the expression of ZEB1, ZEB2 and SNAI1, inducers of epithelial-mesenchymal transition. Novel data indicate that 1,25(OH) 2D 3 has an unanticipated wide regulatory action on the expression of genes coding for histone demethylases of the Jumonji C (JmjC) domain and lysine-specific demethylase (LSD) families. Moreover, JMJD3 knockdown decreases the expression of miR­200b and miR­200c, two microRNAs targeting ZEB1 RNA. This may explain the upregulation of this transcription factor found in JMJD3-depleted cells. Thus, 1,25(OH) 2D 3 exerts an ample regulatory effect on the expression of histone-modifying enzymes involved in epigenetic regulation that may mediate its actions on gene transcription and cell phenotype.