Crosstalk between 1,25(OH)2-Vitamin D3 and the growth factors EGF and PDGF-BB: Impact on CYP24A1 expression and cell proliferation.

This study explored the signaling interplay between the vitamin D receptor (VDR) and receptor tyrosine kinases (RTKs). Epidermal growth factor (EGF) and platelet-derived growth factor (PDGF)-BB promotes cell proliferation in normal and cancer cells. At the same time, the active form of vitamin D (1,25(OH)2-vitamin D3) inhibits proliferation in some cells. Although EGF receptors (EGFR) and PDGF receptors (PDGFR) activate similar downstream pathways, we found that they interact with VDR signaling in distinct ways. We confirmed that 1,25(OH)2-vitamin D3 induces CYP24A1 gene expression in U2OS, T98G, and U251 cells. We found this to be potentiated when combined with EGF. In contrast, PDGF-BB did not impact 1,25(OH)2-vitamin D3-induced CYP24A1 expression in U2OS cells. The increase in CYP24A1 expression due to the combined action of EGF and 1,25(OH)2-vitamin D3 was dependent on AKT and ERK1/2 activation. Another VDR-responsive gene, CYP27B1, was unaffected by the addition of EGF, suggesting that EGF may have gene-specific effects on VDR signaling. While PDGF-BB did not influence CYP24A1 expression, 1,25(OH)2-vitamin D3 significantly influenced PDGF-BB-induced receptor phosphorylation and cell proliferation. In summary, we found that EGF, but not PDGF-BB, influenced the expression of the VDR-dependent gene CYP24A1, while 1,25(OH)2-vitamin D3 had an inhibitory effect on PDGFR signaling and proliferation. These findings highlight unique crosstalk between 1,25(OH)2-vitamin D3 signaling and EGF or PDGF-BB.

Unveiling heterogeneity and prognostic markers in ductal breast cancer through single-cell RNA-seq.

BACKGROUND: Breast cancer (BC) is a heterogeneous disease, with the ductal subtype exhibiting significant cellular diversity that influences prognosis and response to treatment. Single-cell RNA sequencing data from the GEO database were utilized in this study to investigate the underlying mechanisms of cellular heterogeneity and to identify potential prognostic markers and therapeutic targets. METHODS: Bioinformatics analysis was conducted using R packages to analyze the single-cell sequencing data. The presence of highly variable genes and differences in malignant potency within the same BC samples were examined. Differential gene expression and biological function between Type 1 and Type 2 ductal epithelial cells were identified. Lasso regression and Cox proportional hazards regression analyses were employed to identify genes associated with patient prognosis. Experimental validation was performed in vitro and in vivo to confirm the functional relevance of the identified genes. RESULTS: The analysis revealed notable heterogeneity among BC cells, with the presence of highly variable genes and differences in malignant behavior within the same samples. Significant disparities in gene expression and biological function were identified between Type 1 and Type 2 ductal epithelial cells. Through regression analyses, CYP24A1 and TFPI2 were identified as pivotal genes associated with patient prognosis. Kaplan-Meier curves demonstrated their prognostic significance, and experimental validation confirmed their inhibitory effects on malignant behaviors of ductal BC cells. CONCLUSION: This study highlights the cellular heterogeneity in ductal subtype breast cancer and delineates the differential gene expressions and biological functions between Type 1 and Type 2 ductal epithelial cells. The genes CYP24A1 and TFPI2 emerged as promising prognostic markers and therapeutic targets, exhibiting inhibitory effects on BC cell malignancy in vitro and in vivo. These findings offer the potential for improved BC management and the development of targeted treatment strategies.

Gene expression profiling of vitamin D metabolism enzymes in leukemia and lymphoma patients: molecular aspect interplay of VDR, CYP2R1, and CYP24A1.

BACKGROUND: Vitamin D deficiency is prevalent among the Indonesian population, particularly in individuals diagnosed with leukemia-lymphoma. The regulation of vitamin D metabolism is influenced by the expression of several enzymes, such as CYP2R1, CYP24A1, and the vitamin D receptor (VDR). This study aimed to scrutinize the gene expression profiles in both mRNA and protein levels of VDR, CYP2R1, and CYP24A1 in leukemia and lymphoma patients. METHOD: The research was a cross-sectional study conducted at Cipto Mangunkusumo Hospital (RSCM) in Jakarta, Indonesia. The study included a total of 45 patients aged over 18 years old who have received a diagnosis of lymphoma or leukemia. Vitamin D status was measured by examining serum 25 (OH) D levels. The analysis of VDR, CYP2R1, and CYP24A1 mRNA expression utilized the qRT-PCR method, while protein levels were measured through the ELISA method. CONCLUSION: The study revealed a noteworthy difference in VDR protein levels between men and women. The highest mean CYP24A1 protein levels were observed in the age group > 60 years. This study found a significant, moderately positive correlation between VDR protein levels and CYP24A1 protein levels in the male and vitamin D sufficiency groups. In addition, a significant positive correlation was found between VDR mRNA levels and CYP2R1 mRNA levels, VDR mRNA levels and CYP2R1 mRNA levels, and CYP2R1 mRNA levels and CYP24A1 mRNA levels. However, the expression of these genes does not correlate with the protein levels of its mRNA translation products in blood circulation.

Infantile hypercalcemia type 1 (HCINF1): a rare disease resulting in nephrolithiasis and nephrocalcinosis caused by mutations in the vitamin D catabolic enzyme, CYP24A1.

Infantile hypercalcemia type 1 (HCINF1), formerly known as Lightwood syndrome, is a subtype of hypercalcemia caused by loss-of-function biallelic mutations in the vitamin D catabolic enzyme, CYP24A1, which 24-hydroxylates the hormone 1,25-(OH)2D3. This short review focuses on the main features of the HCINF1 disease; emerging knowledge of the structure and function of the cytochrome P450, CYP24A1 and the location of inactivating mutations; the development of a rapid LC-MS/MS-based laboratory test for defective 24-hydroxylation; and future implications for bioanalytical assay and treatment of all types of vitamin D-related hypercalcemic conditions.

Association Between CYP24A1 Polymorphisms and Bladder Cancer Risk in the Chinese Han Population.

In this cohort of 217 bladder cancer patients and 484 healthy controls, we explored the association between CYP24A1 variants (rs2762934, rs1570669, rs6068816, rs2296241) and bladder cancer risk in the Chinese Han population. Utilizing the Agena MassARRAY system, we genotyped four selected CYP24A1 polymorphisms. Logistic regression revealed a significant association of rs2762934 and rs1570669 with elevated bladder cancer risk, while rs6068816 exhibited a protective effect. Bioinformatics analysis of CYP24A1 expression in normal and cancerous bladder tissues indicated higher expression in normal tissue. In conclusion, our findings highlight the potential role of CYP24A1 variants in bladder cancer susceptibility.

Vitamin D-metabolizing enzyme CYP24A1 affects oncogenic behaviors of oral squamous cell carcinoma and its prognostic implication.

Vitamin D is an essential molecule for cellular homeostasis, playing a critical role in cell fate decisions including cell proliferation, differentiation, and viability. Accumulating evidence has revealed that expression of the vitamin D-metabolizing enzyme CYP24A1 is dysregulated in different types of human malignancy. CYP24A1 has been shown to be involved in the oncogenic property of a variety of carcinoma cells. However, the pathological relevance of CYP24A1 expression level in human oral malignancy remains to be clarified. In the present study, suppression of CYP24A1 expression in oral squamous cell carcinoma (OSCC) cells increased cell proliferation, invasive activity, colony formation efficacy, and tumor growth in vivo. In addition, knockout of CYP24A1 expression inhibited cell death induced by two different types of anticancer drugs, i.e., fluorouracil and cisplatin. Gene clustering by RNA-sequence analysis revealed that several signaling molecules associated with MYC are involved in CYP24A1-mediated oncogenic behaviors. Furthermore, decreased expression level of CYP24A1 was observed in 124/204 cases (61%) of OSCC and was shown to be associated with short relapse-free and overall survival periods. The results showed that a low expression level of CYP24A1 promotes the oncogenic activity of OSCC and is significantly associated with poor prognosis in patients with this malignancy.

Rapid genomic changes by mineralotropic hormones and kinase SIK inhibition drive coordinated renal Cyp27b1 and Cyp24a1 expression via CREB modules.

Vitamin D metabolism centers on kidney regulation of Cyp27b1 by mineralotropic hormones, including induction by parathyroid hormone (PTH), suppression by fibroblast growth factor 23 (FGF23) and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), and reciprocal regulations for Cyp24a1. This coordinated genomic regulation results in production of endocrine 1,25(OH)2D3, which, together with PTH and FGF23, controls mineral homeostasis. However, how these events are coordinated is unclear. Here, using in vivo chromatin immunoprecipitation sequencing in mouse kidney, we demonstrate that PTH activation rapidly induces increased recruitment of phosphorylated (p-133) CREB (pCREB) and its coactivators, CBP (CREB-binding protein) and CRTC2 (CREB-regulated transcription coactivator 2), to previously defined kidney-specific M1 and M21 enhancers near the Cyp27b1 gene. At distal enhancers of the Cyp24a1 gene, PTH suppression dismisses CBP with only minor changes in pCREB and CRTC2 occupancy, all of which correlate with decreased genomic activity and reduced transcripts. Treatment of mice with salt-inducible kinase inhibitors (YKL-05-099 and SK-124) yields rapid genomic recruitment of CRTC2 to Cyp27b1, limited interaction of CBP, and a transcriptional response for both Cyp27b1 and Cyp24a1 that mirrors the actions of PTH. Surprisingly, we find that 1,25(OH)2D3 suppression increases the occupancy of CRTC2 in the M1 enhancer, a novel observation for CRTC2 and 1,25(OH)2D3 action. Suppressive actions of 1,25(OH)2D3 and FGF23 at the Cyp27b1 gene are associated with reduced CBP recruitment at these CREB-module enhancers that disrupts full PTH induction. Our findings show that CRTC2 contributes to transcription of both Cyp27b1 and Cyp24a1, demonstrate salt-inducible kinase inhibition as a key modulator of vitamin D metabolism, and provide molecular insight into the coordinated mechanistic actions of PTH, FGF23, and 1,25(OH)2D3 in the kidney that regulate mineral homeostasis.

The CYP24A1 gene variant rs2762943 is associated with low serum 1,25-dihydroxyvitamin D levels in multiple sclerosis patients.

BACKGROUND AND PURPOSE: Vitamin D is considered to play a role in multiple sclerosis (MS) etiopathogenesis. A polymorphism in the CYP24A1 gene, rs2762943, was recently identified that was associated with an increased MS risk. CYP24A1 encodes a protein involved in the catabolism of the active form of vitamin D. The immunological effects of carrying the rs2762943 risk allele were investigated, as well as its role as genetic modifier. METHODS: Serum levels of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D (1,25(OH)2 D) were measured in a cohort of 167 MS patients. In a subgroup of patients, expression levels of major histocompatibility complex class II and co-stimulatory molecules were determined by flow cytometry, and serum levels of pro-inflammatory (interferon gamma, granulocyte macrophage colony-stimulating factor, C-X-C motif chemokine ligand 13) and anti-inflammatory (interleukin 10) cytokines and neurofilament light chain were measured by single-molecule array assays. The effect of the rs2762943 polymorphism on disease activity and disability measures was evaluated in 340 MS patients. RESULTS: Compared to non-carriers, carriers of the rs2762943 risk allele were characterized by reduced levels of 1,25(OH)2 D (p = 0.0001) and elevated levels of interferon gamma (p = 0.03) and granulocyte macrophage colony-stimulating factor (p = 0.008), whereas no significant differences were observed for the other markers. The presence of the rs2762943 risk allele had no significant impact on disease activity and disability outcomes during follow-up. However, risk allele carriers were younger at disease onset (p = 0.04). CONCLUSIONS: These findings suggest that the CYP24A1 rs2762943 polymorphism plays a more important role in MS susceptibility than in disease prognosis and is associated with lower 1,25(OH)2 D levels and a heightened pro-inflammatory environment in MS patients.

Correlation of CYP2R1 gene promoter methylation with circulating vitamin D levels among healthy adults.

Background & objectives: Despite being a tropical country, vitamin D deficiency is highly prevalent in India with studies indicating 40-99 per cent prevalence. Apart from calcium and phosphate metabolism, vitamin D is involved in cell cycle regulation, cardiovascular, hepatoprotection. The metabolism of vitamin D is regulated by vitamin D tool genes (CYP2R1/CYP27B1/CYP24A1/VDR). The promoter regions of some of these genes have CpG islands, making them prone to methylation induced gene silencing, which may cause a reduction in circulating vitamin D levels. Epigenetic basis of vitamin D deficiency is yet to be studied in India, and hence, this pilot study was aimed to analyze whether methylation levels of CYP2R1 gene were correlated with the levels of 25(OH)D in healthy, adult individuals in Indian population. Methods: In this cross-sectional study, healthy adults of 18-45 yr of age with no history of malabsorption, thyroidectomy, chronic illness or therapeutic vitamin D supplementation were recruited. DNA methylation analysis was carried out by methylation specific quantitative PCR. Serum calcium, phosphate and vitamin D levels were also quantified. Statistical analysis was done by R 4.0.5 software. Results: A total of 61 apparently healthy adults were analyzed. The serum vitamin D levels did not correlate with CYP2R1 methylation levels in our study population. Significant positive correlation was observed between age and serum vitamin D levels. Significant association of gender was found with CYP2R1 methylation levels. Interpretation & conclusions: This study found no significant correlation between levels of CYP2R1 methylation and circulating 25(OH)D deficiency. Further studies on the Indian population having a larger sample size including entire vitamin D tool genes, among different ethnic groups may be conducted to elucidate molecular etiology of circulating 25(OH)D deficiency. The high prevalence of normal serum calcium and phosphate levels among vitamin D deficient subjects in this study coupled with the strikingly high prevalence of the deficiency at the national level, may suggest the need to revise the cut-off criteria for vitamin D deficiency in the Indian population.

Genetic polymorphisms of CYP24A1 gene and cancer susceptibility: a meta-analysis including 40640 subjects.

BACKGROUND: Whether cytochrome P450 24A1 (CYP24A1) polymorphism is associated with cancer susceptibility, the individual study results are still controversial. Therefore, we performed a comprehensive study to identify the association of CYP24A1 polymorphisms (rs4809960, rs6068816, rs2296241, rs4809957, rs2762939) with cancer susceptibility. METHODS: Electronic databases including Cochrane Library, PubMed, and Embase were systematically retrieved for relevant publications. Fixed or random-effect model was selected to calculate odds ratios (ORs) with their 95% confidence intervals (95%CI). RESULTS: Eighteen published articles were identified. The results indicated that rs4809960 polymorphism was associated with a decreased cancer risk in Caucasian (TT vs. TC+CC: P=0.035; C vs. T: P=0.016) and Asian population (CC vs. TC+TT: OR P=0.044; TT vs. TC+CC: P=0.021; CC vs. TT: P=0.020; C vs. T: P=0.008) and breast cancer risk (TT vs. TC+CC: P = 0.007; TC vs. TT: P=0.004; C vs. T: P=0.033). A significant association was found between rs2296241 polymorphism and esophageal squamous cell carcinoma risk (AA vs. GG+AG: P = 0.023) and prostate cancer susceptibility (A vs. G: P=0.022). Furthermore, rs4809957 polymorphism was associated with prostate cancer susceptibility in Caucasian (GG vs. GA+AA: P=0.029; GA vs. GG: P=0.022) and breast cancer susceptibility (AA vs. GG+GA: P=0.012; AA vs. GG, P=0.010; A vs. G: P=0.024). Additionally, rs6068816 polymorphism significantly decreased the lung cancer (CC vs. CT+TT: P = 0.016; TT vs. CC: P = 0.044; CT vs. CC: P = 0.036; T vs. C: P = 0.016) and breast cancer risk (TT vs. CC+CT: P = 0.043; TT vs. CC: P = 0.039). No association was found for rs2762939 polymorphism with overall cancer risk. However, for rs2296241, rs4809957, and rs6068816 polymorphisms, there were no significant differences after the Bonferroni correction. CONCLUSION: The meta-analysis suggested that rs4809960 was associated with cancer risk and might be a genetic marker for predicting cancer risk. More large-scale and large-sample studies are necessary to further confirm these results.

Circular RNA Circ_0005962 Contributes to Lung Adenocarcinoma Cell Proliferation and Stem Cell Formation Through Sponging of miR-3611 and Modulating CYP24A1 Expression.

Recently, several studies have revealed that circular RNAs (circRNAs) play significant roles in various tumors, including lung adenocarcinoma (LUAD). Furthermore, it has been reported that circ_0005962 was upregulated in LUAD cells. Accordingly, this research is designed to investigate the mechanism of circ_0005962 on LUAD development. Circ_0005962, microRNA-3611 (miR-3611), and Cytochrome P450 family 24 subfamily A member 1 (CYP24A1) level were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation ability, cell cycle progression, and sphere formation ability were detected using Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), Colony formation, flow cytometry, and sphere formation assay. Protein levels of proliferating cell nuclear antigen (PCNA), Ki67, NANOG, CD133, OCT4, and CYP24A1 were determined using Western blot assay. Using bioinformatics software (Starbase3.0 and TargetScan), the binding between miR-3611 and circ_0005962 or CYP24A1 was predicted and proved using RNA Immunoprecipitation (RIP) and RNA pull-down assays. A xenograft tumor model in vivo was used to analyze the biological role of circ_0005962 on LUAD cell growth. Increased circ_0005962 and CYP24A1, and reduced miR-3611 were observed in LUAD tissues and cell lines. Functional assays testified that circ_0005962 depletion might hinder LUAD cell proliferation and sphere formation capability, but induced cell apoptosis in vitro. Molecular mechanism experiments exhibited that circ_0005962 served as a miR-3611 sponge and mediated CYP24A1 content by absorbing miR-3611. Additionally, silencing of circ_0005962 inhibited tumor growth in xenograft modes. Together, circ_0005962 was overexpressed in LUAD, and its deficiency repressed LUAD progression via targeting the miR-3611/ CYP24A1 axis, providing a novel mechanism for understanding the development of LUAD.

Transcriptome-wide profile of 1α,25 dihydroxyvitamin D3 in HTR-8/SVneo cells.

AIM: Vitamin D3 has been implicated in multiple reproductive events, whereas the effect of its bioactive metabolite 1α, 25 dihydroxyvitamin D3 (1,25(OH) 2 D3 ) on transcriptome profile of the placenta is unclear. The aim of this article is to determine transcriptome-wide profile caused by 1,25(OH) 2 D3 in human placental trophoblast cells. METHODS: We performed RNA sequencing after stimulation of HTR-8/SVneo cells with 0.1, 1, 10, and 100 nM 1,25(OH)2 D3 for 24 h, identified differentially expressed genes by edgeR package (version 3.38.4), and analyzed Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways by webtool Metascape. Also, common genes and specific genes in different concentrations of 1,25(OH) 2 D3 were identified. RESULTS: There were 180, 158, 161, and 174 differentially expressed genes after 0.1, 1, 10, and 100 nM 1,25(OH) 2 D3 stimulation, respectively. KEGG pathway analysis displayed that "lipid and atherosclerosis" were significantly enriched at 0.1 and 1 nM 1,25(OH)2 D3 , while "cytokine-cytokine receptor interaction," "TGF-beta signaling pathway" and "hippo signaling pathway" were significantly enriched in 1, 10, and 100 nM 1,25(OH)2 D3 . CYP24A1 was a significantly expressed common gene. UCP3 was significantly expressed in low concentrations and might affect energy metabolism. TCF24, EIF3CL, ABCD2, EPHA7, CRLF1, and SECTM1 were specific genes at physiological concentration. Similarly, SPDYE1, IQUB, IL18R1, and ZNF713 were considered as specific genes at supraphysiological concentration. CONCLUSIONS: 1,25(OH)2 D3 mainly affected the expression of CYP24A1 gene in HTR-8/SVneo cells. Specific genes accounted for the majority of differentially expressed genes at different concentrations. However, their functions need to be further confirmed.

Synthesis of New 26,27-Difluoro- and 26,26,27,27-Tetrafluoro-25-hydroxyvitamin D3: Effects of Terminal Fluorine Atoms on Biological Activity and Half-life.

As an extension of our research on providing a chemical library of side-chain fluorinated vitamin D3 analogues, we newly designed and synthesized 26,27-difluoro-25-hydroxyvitamin D3 (1) and 26,26,27,27-tetrafluoro-25-hydroxyvitamin D3 (2) using a convergent method applying the Wittig-Horner coupling reaction between CD-ring ketones (13, 14) and A-ring phosphine oxide (5). The basic biological activities of analogues, 1, 2, and 26,26,26,27,27,27-hexafluoro-25-hydroxyvitamin D3 [HF-25(OH)D3] were examined. Although the tetrafluorinated new compound 2 exhibited higher binding affinity for vitamin D receptor (VDR) and resistance to CYP24A1-dependent metabolism compared with the difluorinated 1 and its non-fluorinated counterpart 25-hydroxyvitamin D3 [25(OH)D3], HF-25(OH)D3 showed the highest activity among these compounds. Osteocalcin promoter transactivation activity of these fluorinated analogues was tested, and it decreased in the order of HF-25(OH)D3, 2, 1, and 25(OH)D3 in which HF-25(OH)D3 showed 19-times greater activity than the natural 25(OH)D3.

Single Nucleotide Polymorphisms in the Vitamin D Metabolic Pathway and Their Relationship with High Blood Pressure Risk.

High blood pressure (HBP) is the leading risk factor for cardiovascular disease (CVD) and all-cause mortality worldwide. The progression of the disease leads to structural and/or functional alterations in various organs and increases cardiovascular risk. Currently, there are significant deficiencies in its diagnosis, treatment, and control. Vitamin D is characterized by its functional versatility and its involvement in countless physiological processes. This has led to the association of vitamin D with many chronic diseases, including HBP and CVD, due to its involvement in the regulation of the renin-angiotensin-aldosterone system. The aim of this study was to evaluate the effect of 13 single nucleotide polymorphisms (SNPs) related to the vitamin D metabolic pathway on the risk of developing HBP. An observational case-control study was performed, including 250 patients diagnosed with HBP and 500 controls from the south of Spain (Caucasians). Genetic polymorphisms in CYP27B1 (rs4646536, rs3782130, rs703842, and rs10877012), CYP2R1 rs10741657, GC rs7041, CYP24A1 (rs6068816, and rs4809957), and VDR (BsmI, Cdx2, FokI, ApaI, and TaqI) were analyzed by real-time PCR using TaqMan probes. Logistic regression analysis, adjusted for body mass index (BMI), dyslipidemia, and diabetes, showed that in the genotypic model, carriers of the GC rs7041 TT genotype were associated with a lower risk of developing HBP than the GG genotype (odds ratio (OR) = 0.44, 95% confidence interval (CI): 0.41-0.77, p = 0.005, TT vs. GG). In the dominant model, this association was maintained; carriers of the T allele showed a lower risk of developing HBP than carriers of the GG genotype (OR = 0.69, 95% CI: 0.47-1.03; TT + TG vs. GG, p = 0.010). Finally, in the additive model, consistent with previous models, the T allele was associated with a lower risk of developing HBP than the G allele (OR = 0.65, 95% CI: 0.40-0.87, p = 0.003, T vs. G). Haplotype analysis revealed that GACATG haplotypes for SNPs rs1544410, rs7975232, rs731236, rs4646536, rs703842, and rs10877012 were associated with a marginally significant lower risk of developing HBP (OR = 0.35, 95% CI: 0.12-1.02, p = 0.054). Several studies suggest that GC 7041 is associated with a lower active isoform of the vitamin D binding protein. In conclusion, the rs7041 polymorphism located in the GC gene was significantly associated with a lower risk of developing HBP. This polymorphism could therefore act as a substantial predictive biomarker of the disease.

Vitamin D metabolism in cancer: potential feasibility of vitamin D metabolism blocking therapy.

In this review, we discuss the possibility of the vitamin D metabolizing enzyme CYP24A1 being a therapeutic target for various tumors including breast, colorectal and prostate tumors. Given the pleiotropic cellular activity of vitamin D, its deficiency impairs its physiological function in target cells and results in various pathologies including cancer. In addition, accumulated data have shown that elevated expression of CYP24A1 promotes carcinogenesis in various cancer subtypes by decreasing the bioavailability of vitamin D metabolites. Thus, we propose the potential feasibility of vitamin D metabolism-blocking therapy in various types of human malignancies that express constitutive CYP24A1.

Elucidation of metabolic pathways of 25-hydroxyvitamin D3 mediated by CYP24A1 and CYP3A using Cyp24a1 knockout rats generated by CRISPR/Cas9 system.

CYP24A1-deficient (Cyp24a1 KO) rats were generated using the CRISPER/Cas9 system to investigate CYP24A1-dependent or -independent metabolism of 25(OH)D3, the prohormone of calcitriol. Plasma 25(OH)D3 concentrations in Cyp24a1 KO rats were approximately twofold higher than in wild-type rats. Wild-type rats showed five metabolites of 25(OH)D3 in plasma following oral administration of 25(OH)D3, and these metabolites were not detected in Cyp24a1 KO rats. Among these metabolites, 25(OH)D3-26,23-lactone was identified as the second major metabolite with a significantly higher Tmax value than others. When 23S,25(OH)2D3 was administered to Cyp24a1 KO rats, neither 23,25,26(OH)3D3 nor 25(OH)D3-26,23-lactone was observed. However, when 23S,25R,26(OH)3D3 was administered to Cyp24a1 KO rats, plasma 25(OH)D3-26,23-lactone was detected. These results suggested that CYP24A1 is responsible for the conversion of 25(OH)D3 to 23,25,26(OH)3D3 via 23,25(OH)2D3, but enzyme(s) other than CYP24A1 may be involved in the conversion of 23,25,26(OH)3D3 to 25(OH)D3-26,23-lactone. Enzymatic studies using recombinant human CYP species and the inhibitory effects of ketoconazole suggested that CYP3A plays an essential role in the conversion of 23,25,26(OH)3D3 into 25(OH)D3-26,23-lactone in both rats and humans. Taken together, our data indicate that Cyp24a1 KO rats are valuable for metabolic studies of vitamin D and its analogs. In addition, long-term administration of 25(OH)D3 to Cyp24a1 KO rats at 110 µg/kg body weight/day resulted in significant weight loss and ectopic calcification. Thus, Cyp24a1 KO rats could represent an important model for studying renal diseases originating from CYP24A1 dysfunction.

Association of CYP24A1 with survival and drug resistance in clinical cancer patients: a meta-analysis.

BACKGROUND: Acquired chemo-drug resistance constantly led to the failure of chemotherapy for malignant cancers, consequently causing cancer relapse. Hence, identifying the biomarker of drug resistance is vital to improve the treatment efficacy in cancer. The clinical prognostic value of CYP24A1 remains inconclusive, hence we aim to evaluate the association between CYP24A1 and the drug resistance in cancer patients through a meta-analysis approach. METHOD: Relevant studies detecting the expression or SNP of CYP24A1 in cancer patients up till May 2022 were systematically searched in four common scientific databases including PubMed, EMBASE, Cochrane library and ISI Web of Science. The pooled hazard ratios (HRs) indicating the ratio of hazard rate of survival time between CYP24A1high population vs CYP24A1low population were calculated. The pooled HRs and odds ratios (ORs) with 95% confidence intervals (CIs) were used to explore the association between CYP24A1's expression or SNP with survival, metastasis, recurrence, and drug resistance in cancer patients. RESULT: Fifteen studies were included in the meta-analysis after an initial screening according to the inclusion and exclusion criteria. There was a total of 3784 patients pooled from all the included studies. Results indicated that higher expression or SNP of CYP24A1 was significantly correlated with shorter survival time with pooled HRs (95% CI) of 1.21 (1.12, 1.31), metastasis with pooled ORs (95% CI) of 1.81 (1.11, 2.96), recurrence with pooled ORs (95% CI) of 2.14 (1.45, 3.18) and drug resistance with pooled HRs (95% CI) of 1.42 (1.17, 1.68). In the subgroup analysis, cancer type, treatment, ethnicity, and detection approach for CYP24A1 did not affect the significance of the association between CYP24A1 expression and poor prognosis. CONCLUSION: Findings from our meta-analysis demonstrated that CYP24A1's expression or SNP was correlated with cancer progression and drug resistance. Therefore, CYP24A1 could be a potential molecular marker for cancer resistance.

Codelivery of 1α,25-Dihydroxyvitamin D3 and CYP24A1 Inhibitor VID400 by Nanofiber Dressings Promotes Endogenous Antimicrobial Peptide LL-37 Induction.

Surgical site infections represent a significant clinical problem. Herein, we report a nanofiber dressing for topical codelivery of immunomodulating compounds including 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) and VID400, a CYP24A1 inhibitor in a sustained manner, for inducing the expression of the endogenous cathelicidin antimicrobial peptide (CAMP) gene encoding the hCAP18 protein, which is processed into the LL-37 peptide. Nanofiber wound dressings with coencapsulation of 1,25(OH)2D3 and VID400 were generated by electrospinning. Both 1,25(OH)2D3 and VID400 were coencapsulated into nanofibers with loading efficiencies higher than 90% and exhibited a prolonged release from nanofiber membranes longer than 28 days. Incubation with 1,25(OH)2D3/VID400-coencapsulated poly(ϵ-caprolactone) nanofiber membranes greatly induced the hCAP18/LL-37 gene expression in monocytes, neutrophils, and keratinocytes in vitro. Moreover, the administration of 1,25(OH)2D3/VID400-coencapsulated nanofiber membranes dramatically promoted the hCAP18/LL-37 expression in dermal wounds created in both human CAMP transgenic mice and human skin tissues. The 1,25(OH)2D3- and VID400-coencapsulated nanofiber dressings enhanced innate immunity via the more effective induction of antimicrobial peptide than the free drug alone or 1,25(OH)2D3-loaded nanofibers. Together, 1,25(OH)2D3/VID400-embedded nanofiber dressings presented in this study show potential in preventing surgical site infections.

MiR-30b-5p attenuates neuropathic pain by the CYP24A1-Wnt/ß-catenin signaling in CCI rats.

MicroRNAs (miRNAs) has been reported to act as key regulators of neuronal function. Increasing evidence has showed that miRNAs exert significant effects in neuropathic pain. We explored the role of miR-30b-5p in neuropathic pain by establishing a rat model of chronic constrictive injury (CCI). The sciatic nerve of CCI rats was used to induce chronic neuropathic pain. The expression and cellular distribution of miR-30b-5p were determined by RT-qPCR and FISH. The mRNA level, protein level, and cellular distribution of CYP24A1 were detected by RT-qPCR, western blot, and immunofluorescence staining assays, respectively. The interaction between miR-30b-5p and CYP24A1 was examined by a luciferase reporter assay. The behavioral effects of miR-30b-5p were assessed after intrathecal administration. Mechanical stimuli and radiant heat were applied to assess mechanical allodynia and thermal hyperalgesia of rats. ELISA was performed to measure the concentration of inflammatory cytokines. MiR-30b-5p expression was significantly downregulated in the spinal cord tissues and of CCI rats. Overexpression of miR-30b-5p attenuated symptoms of neuropathic pain, including mechanical allodynia and thermal hyperalgesia. Additionally, miR-30b-5p overexpression suppressed neuroinflammation by reducing the levels of IL-6, TNF-α and COX2 and elevating the levels of IL-10 in CCI rats. Mechanistically, CYP24A1 was a target of miR-30b-5p, and its expression was negatively regulated by miR-30b-5p. Moreover, CYP24A1 expression was upregulated in CCI rats and knockdown of CYP24A1 attenuated neuropathic pain and neuroinflammation. Furthermore, miR-30b-5p reduced the levels of the Wnt pathway-related genes in CCI rats by downregulating CYP24A1. Rescue assays showed that overexpression of CYP24A1 or activation of Wnt pathway reduced the alleviative effects of miR-30b-5p overexpression on neuropathic pain in CCI rats. Overall, miR-30b-5p inhibits neuropathic pain progression in CCI rats by inhibiting the CYP24A1-Wnt/ß-catenin pathway.

Ca2+/Calmodulin induces translocation of membrane-associated TSC2 to the nucleus where it suppresses CYP24A1 expression.

Tuberous sclerosis complex 2 (TSC2) is a tumor-suppressor protein. A loss of TSC2 function induces hyperactivation of mechanistic target of rapamycin (mTOR). The C-terminal region of TSC2 contains a calmodulin (CaM) binding region and the CaM-TSC2 interaction contributes to proper mTOR activity. However, other downstream signaling pathways/effectors activated by the CaM-TSC2 complex have not been fully elucidated. In this study, we found that activation of Ca2+/CaM signaling resulted in the translocation of membrane-associated TSC2 to the nucleus and suppressed the transcriptional activity of the vitamin D receptor (VDR). TSC2 was released from the membrane in an activated CaM-dependent state in rat brain and HeLa cells. It subsequently formed a transcriptional complex to partially suppress the transcription of CYP24A1, a well-known VDR target gene. These data suggest, in part, that TSC2 attenuates VDR-associated transcriptional regulation via Ca2+/CaM signaling.