Role of vitamin D and vitamin D receptor (VDR) in oral cancer

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.

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

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

Dissection of an impact of VDR and RXRA on the genomic activity of 1,25(OH)2D3 in A431 squamous cell carcinoma

BACKGROUND

Human skin is the natural source, place of metabolism, and target for vitamin D3. The classical active form of vitamin D3, 1,25(OH)2D3, expresses pluripotent properties and is intensively studied in cancer prevention and therapy. To define the specific role of vitamin D3 receptor (VDR) and its co-receptor retinoid X receptor alpha (RXRA) in genomic regulation, VDR or RXRA genes were silenced in the squamous cell carcinoma cell line A431 and treated with 1,25(OH)2D3 at long incubation time points 24 h/72 h. Extending the incubation time of A431 WT (wild-type) cells with 1,25(OH)2D3 resulted in a two-fold increase in DEGs (differentially expressed genes) and a change in the amount of downregulated from 37% to 53%. VDR knockout led to a complete loss of 1,25(OH)2D3-induced genome-wide gene regulation at 24 h time point, but after 72 h, 20 DEGs were found, of which 75% were downregulated, and most of them belonged to the gene ontology group "immune response". This may indicate the existence of an alternative, secondary response to 1,25(OH)2D3. In contrast, treatment of A431 ΔRXRA cells with 1,25(OH)2D3 for 24 h only partially affected DEGs, suggesting RXRA-independent regulation. Interestingly, overexpression of classic 1,25(OH)2D3 targets, like CYP24A1 (family 24 of subfamily A of cytochrome P450 member 1) or CAMP (cathelicidin antimicrobial peptide) was found to be RXRA-independent. Also, immunofluorescence staining of A431 WT cells revealed partial VDR/RXRA colocalization after 24 h and 72 h 1,25(OH)2D3 treatment. Comparison of transcriptome changes induced by 1,25(OH)2D3 in normal keratinocytes vs. cancer cells showed high cell type specific expression pattern with only a few genes commonly regulated by 1,25(OH)2D3. Activation of the genomic pathway at least partially reversed the expression of cancer-related genes, forming a basis for anti-cancer activates of 1,25(OH)2D3. In summary, VDR or RXRA independent genomic activities of 1,25(OH)2D3 suggest the involvement of alternative factors, opening new challenges in this field.

Delineating the role of nuclear receptors in colorectal cancer, a focused review

Colorectal cancer (CRC) stands as one of the most prevalent form of cancer globally, causing a significant number of deaths, surpassing 0.9 million in the year 2020. According to GLOBOCAN 2020, CRC ranks third in incidence and second in mortality in both males and females. Despite extensive studies over the years, there is still a need to establish novel therapeutic targets to enhance the patients' survival rate in CRC. Nuclear receptors (NRs) are ligand-activated transcription factors (TFs) that regulate numerous essential biological processes such as differentiation, development, physiology, reproduction, and cellular metabolism. Dysregulation and anomalous expression of different NRs has led to multiple alterations, such as impaired signaling cascades, mutations, and epigenetic changes, leading to various diseases, including cancer. It has been observed that differential expression of various NRs might lead to the initiation and progression of CRC, and are correlated with poor survival outcomes in CRC patients. Despite numerous studies on the mechanism and role of NRs in this cancer, it remains of significant scientific interest primarily due to the diverse functions that various NRs exhibit in regulating key hallmarks of this cancer. Thus, modulating the expression of NRs with their agonists and antagonists, based on their expression levels, holds an immense prospect in the diagnosis, prognosis, and therapeutical modalities of CRC. In this review, we primarily focus on the role and mechanism of NRs in the pathogenesis of CRC and emphasized the significance of targeting these NRs using a variety of agents, which may represent a novel and effective strategy for the prevention and treatment of this cancer.

Relationship between human papillomavirus and serum vitamin D levels: a systematic review

BACKGROUND

Human papillomavirus (HPV) is one of the most prevalent sexually transmitted diseases worldwide. The present review was conducted to accumulate evidence on the relationship between cervicovaginal human papillomavirus infection and serum vitamin D status.

METHODS

Electronic databases including Web of Science, Embase, Scopus, and PubMed were searched by different combinations of keywords related to "human papillomavirus" and "vitamin D", obtained from Mesh and Emtree with AND, and OR operators without any time restriction until December 24, 2022. Selection of articles was based on the inclusion and exclusion criteria. Newcastle-Ottawa Scale was used for quality assessment. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist was applied for reporting.

RESULTS

In total, 276 citations were retrieved. After removing duplicates, and non-related articles, the full texts of 7 articles were reviewed including 11168 participants. Three studies reported that there was a positive relationship between vitamin D deficiency and cervicovaginal human papillomavirus while three studies did not. One study showed a significant positive association between higher vitamin D stores and short-term high-risk human papillomavirus persistence.

CONCLUSIONS

The findings showed no firm evidence for any association between serum vitamin D level and cervicovaginal human papillomavirus infection, although the possible association could not be discarded. Further investigations are needed to reach sound evidence.

The Role of Vitamins in Oral Potentially Malignant Disorders and Oral Cancer: A Systematic Review

BACKGROUND

Micronutrients are vital for general and oral health, and their potential anti-cancer properties are documented. We explore beneficial vitamins for oral potentially malignant disorders (OPMDs) and oral cancer (OC), assessing the therapeutic impacts of essential vitamin supplementation.

METHODS

We systematically review evidence on vitamin supplementation's therapeutic effects for OPMDs and OC. Relevant studies were identified through comprehensive searches of MEDLINE, Evidence-Based Medicine, and Web of Science until 16 May 2023. All studies underwent risk of bias using criteria modified from the Office of Health Assessment and Translation (OHAT) tool.

RESULTS

We analysed 80 papers. Vitamin K, studied in vitro, shows promising therapeutic potential. Vitamin C, investigated in vivo (animals and humans), demonstrated mixed animal results and generally positive human trial effects. Vitamin A's efficacy varied, with positive monotherapy or adjunct effects. Vitamins B and D showed therapeutic benefits. Oral cancer research was extensive, with a focus on oral lichen planus and oral leukoplakia among the 11 OPMDs. All bias levels were reported in 'selective reporting' and 'performance', except for "definitely high" in the 'selection', 'detection', and 'attrition/exclusion' domains.

CONCLUSIONS

Evidence of vitamin interventions for OPMDs and OC ranges from mixed to promising. Standardizing the study design and outcomes would enhance future research.

Vitamin D3 regulates NSUN2 expression and inhibits melanoma cell proliferation and migration

The activated form of vitamin D3 [1,25-dihydroxyvitamin D3; 1,25(OH)2D3] is important for various physiological processes, such as bone mineralization and calcium metabolism, and plays an anticancer role in numerous cancers as well. Its role in melanoma cells has yet to be proven. NOP2/Sun RNA methyltransferase 2 (NSUN2) is a typical RNA methyltransferase and is highly expressed in a variety of cancer cells. However, the molecular mechanisms underlying the role of 1,25(OH)2D3 and NSUN2 in melanoma cells remain largely unknown. The current study showed that 1,25(OH)2D3 could significantly and specifically inhibit the proliferation and migration of melanoma B16 cells. 1,25(OH)2D3 enhances vitamin D receptor expression while simultaneously reducing NSUN2 expression in melanoma cells. Subsequently, knockdown of NSUN2 suppressed B16 cell proliferation and migration. RNA-Seq results illuminated that DNA replication, cell proliferation and cell cycle pathways were enriched, and genes promoting these pathways were reduced after knocking down Nsun2. Dual-luciferase reporter assays showed that 1,25(OH)2D3 downregulated reporter gene expression was controlled by the Nsun2 promoter. The results suggest that 1,25(OH)2D3 binds to the vitamin D response element located upstream of the Nsun2 promoter to downregulate Nsun2 transcription activity and then affects the gene expression pattern related to cell proliferation and the cell cycle, thereby restraining B16 cell proliferation and migration.

Maternal Vitamin D and Inulin Supplementation in Oxidized Oil Diet Improves Growth Performance and Hepatic Innate Immunity in Offspring Mice

Dietary oxidized fat contains harmful materials such as hydrogen peroxide and malondialdehyde (MDA). Excessive oxidized fat intake during pregnancy and lactation not only leads to maternal body injury but also damages offspring health. Our previous study demonstrated that vitamin D (VD) had antioxidative capability in sows. This study was conducted to investigate the effect of maternal VD and inulin supplementation in oxidized oil diet on the growth performance and oxidative stress of their offspring. Sixty 5-month-old C57BL/6N female mice were randomly divided into five groups: Control group (basal diet, n = 12), OF group (oxidized-soybean-oil-replaced diet, n = 12), OFV group (oxidized-soybean-oil-replaced diet + 7000 IU/kg VD, n = 12), OFI group (oxidized-soybean-oil-replaced diet + 5% inulin, n = 12) and OFVI group (oxidized-soybean-oil-replaced diet + 7000 IU/kg VD + 5% inulin, n = 12). Mice were fed with the respective diet during pregnancy and lactation. The offspring were then slaughtered on day 21 of age at weaning. Results showed that a maternal oxidized oil diet impaired body weight and liver weight gain of offspring during lactation compared to the control group, while maternal VD, inulin or VD and inulin mixture supplementation reversed this effect. In addition, the activity of T-AOC in the liver of offspring was lower in the OF group than that in the control group, but could be restored by maternal VD and inulin mixture supplementation. Furthermore, the gene expression of both proinflammatory and anti-inflammatory cytokines, such as Il-6, Tnfα and Il-10, in offspring liver were downregulated by a maternal oxidized oil diet compared with the control group, but they were restored by maternal VD or VD and inulin mixture supplementation. The expressions of Vdr and Cyp27a1 were decreased by a maternal oxidized oil diet compared with the control group, while they could be increased by VD or VD and inulin mixture supplementation. Conclusion: maternal oxidized oil diet intake could impair the growth performance by inducing oxidative stress, but this can be relieved by maternal VD and inulin supplementation.

Role of Vitamin D in Head and Neck Cancer-Immune Function, Anti-Tumour Effect, and Its Impact on Patient Prognosis

Head and neck squamous cell carcinoma (HNSCC) describes a heterogeneous group of human neoplasms of the head and neck with high rates of morbidity and mortality, constituting about 3% of all cancers and ~1.5% of all cancer deaths. HNSCC constituted the seventh most prevalent human malignancy and the most common human cancer in the world in 2020, according to multi-population observations conducted by the GLOBOCAN group. Since approximately 60-70% of patients present with stage III/IV neoplastic disease, HNSCC is still one of the leading causes of death in cancer patients worldwide, with an overall survival rate that is too low, not exceeding 40-60% of these patients. Despite the application of newer surgical techniques and the implementation of modern combined oncological treatment, the disease often follows a fatal course due to frequent nodal metastases and local neoplastic recurrences. The role of micronutrients in the initiation, development, and progression of HNSCC has been the subject of considerable research. Of particular interest has been vitamin D, the pleiotropic biologically active fat-soluble family of secosteroids (vitamin-D-like steroids), which constitutes a key regulator of bone, calcium, and phosphate homeostasis, as well as carcinogenesis and the further development of various neoplasms. Considerable evidence suggests that vitamin D plays a key role in cellular proliferation, angiogenesis, immunity, and cellular metabolism. A number of basic science, clinical, and epidemiological studies indicate that vitamin D has multidirectional biological effects and influences anti-cancer intracellular mechanisms and cancer risk, and that vitamin D dietary supplements have various prophylactic benefits. In the 20th century, it was reported that vitamin D may play various roles in the protection and regulation of normal cellular phenotypes and in cancer prevention and adjunctive therapy in various human neoplasms, including HNSCC, by regulating a number of intracellular mechanisms, including control of tumour cell expansion and differentiation, apoptosis, intercellular interactions, angio- and lymphogenesis, immune function, and tumour invasion. These regulatory properties mainly occur indirectly via epigenetic and transcriptional changes regulating the function of transcription factors, chromatin modifiers, non-coding RNA (ncRNAs), and microRNAs (miRs) through protein-protein interactions and signalling pathways. In this way, calcitriol enhances intercellular communication in cancer biology, restores the connection with the extracellular matrix, and promotes the epithelial phenotype; it thus counteracts the tumour-associated detachment from the extracellular matrix and inhibits the formation of metastases. Furthermore, the confirmation that the vitamin D receptor (VDR) is present in many human tissues confirmed the physiopathological significance of vitamin D in various human tumours. Recent studies indicate quantitative associations between exposure to vitamin D and the incidence of HNC, i.e., cancer risk assessment included circulating calcidiol plasma/serum concentrations, vitamin D intake, the presence of the VDR gene polymorphism, and genes involved in the vitamin D metabolism pathway. Moreover, the chemopreventive efficacy of vitamin D in precancerous lesions of the head and neck and their role as predictors of mortality, survival, and recurrence of head and neck cancer are also widely discussed. As such, it may be considered a promising potential anti-cancer agent for developing innovative methods of targeted therapy. The proposed review discusses in detail the mechanisms regulating the relationship between vitamin D and HNSCC. It also provides an overview of the current literature, including key opinion-forming systematic reviews as well as epidemiological, prospective, longitudinal, cross-sectional, and interventional studies based on in vitro and animal models of HNSCC, all of which are accessible via the PubMed/Medline/EMBASE/Cochrane Library databases. This article presents the data in line with increasing clinical credibility.

Vitamin D in the Prevention and Treatment of Oral Cancer: A Scoping Review

Introduction: Oral cancer is a serious health problem with an increasing incidence worldwide. Researchers have studied the potential anti-cancerous action of vitamin D and its association with several cancers including oral cancer. The purpose of this scoping review is to synthesize the existing literature on the role of vitamin D on oral cancer. Methods: A scoping review of the literature was conducted using the framework developed by Arkey and O'Malley and the PRISMA-ScR guidelines. Nine databases were searched for peer-reviewed human studies published in English that either investigated the association of vitamin D with, or its impact on either the prevention or treatment of oral cancer. The authors then extracted data using a predefined form to summarize information about article type, study design, participant characteristics, interventions, and outcomes. Results: Fifteen articles met the review criteria. Among the 15 studies, 11 were case-control, 3 were cohort studies, and 1 was a clinical trial. In four studies, the evidence supported a preventive action of vitamin D against oral cancer and a reduction in the negative side effects associated with chemo- and radiotherapy. Several studies that focused on genetic polymorphisms and the expression of the 1,25 dihydroxyvitamin D3 receptor (VDR) suggested significant associations with vitamin D and increased oral cancer risk and worse survival rates. In contrast, two studies did not reveal a strong association between vitamin D and oral cancer. Conclusions: The current evidence suggests an association between vitamin D deficiency and an increased risk of oral cancer. VDR gene polymorphisms might also be a part of future preventive and therapeutic strategies against oral cancer. Carefully designed studies are required to explore and define what role, if any, vitamin D might play in the prevention and treatment of oral cancer.

1,25D/VDR inhibits pancreatic β cell ferroptosis by downregulating FOXO1 expression in diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a global health problem that seriously threatens human health. Vitamin D (VD) has antidiabetic effects. However, the protective mechanism of 1,25-dihydroxyvitamin D3 (1,25D) on T2DM is still unclear.

METHODS

A rat model of T2DM was constructed using a high-fat diet combined with intraperitoneal injection of streptozotocin (STZ). Glucose tolerance was assessed by an oral glucose tolerance test (OGTT). Insulin secretion in blood and cell supernatant was determined by ELISA. Cell viability was analysed by CCK-8 assay. The level of ROS was detected by the DCFH-DA fluorescent probe method. The iron level in pancreatic tissues and cells was detected by an iron assay kit. Immunofluorescence staining was used to detect the expression of the pancreatic β cell marker CD49a. Furthermore, the protein expression levels of ferroptosis pathway-related proteins and vitamin D receptor (VDR) were detected by western blot. Downstream VDR targets were screened by proteomic sequencing.

RESULTS

The DM group had increased glucose levels and decreased insulin secretion, while 1,25D treatment decreased glucose levels and increased insulin secretion. 1,25D also suppressed DM-induced ferroptosis in pancreatic tissues in vivo. In addition, 1,25D significantly enhanced the viability of pancreatic β cells and reduced the levels of ROS and iron. 1,25D significantly upregulated the expression of VDR and the ferroptosis-related pathway protein GPX4 and downregulated the expression of ACSL4. Furthermore, knockdown of VDR reversed the effects of 1,25D on cell viability, ROS and iron levels, and ferroptosis-related protein expression in pancreatic β cells. Proteomic sequencing revealed that FOXO1 was the downstream target gene of VDR. Knockdown of FOXO1 reduced pancreatic β cell death, decreased ROS, iron and ACSL4 levels, and increased GPX4 levels.

CONCLUSION

1,25D/VDR inhibited pancreatic β cell ferroptosis in T2DM by downregulating the expression of FOXO1. This study provides a new theoretical basis for basic research on T2DM and is expected to establish a new idea for the treatment of T2DM.

Vitamin D Modulates the Response of Patient-Derived Metastatic Melanoma Cells to Anticancer Drugs

Melanoma is considered a lethal and treatment-resistant skin cancer with a high risk of recurrence, making it a major clinical challenge. Our earlier studies documented that 1,25(OH)₂D₃ and its low-calcaemic analogues potentiate the effectiveness of dacarbazine and cediranib, a pan-VEGFR inhibitor. In the current study, a set of patient-derived melanoma cultures was established and characterised as a preclinical model of human melanoma. Thus, patient-derived cells were preconditioned with 1,25(OH)₂D₃ and treated with cediranib or vemurafenib, a BRAF inhibitor, depending on the BRAF mutation status of the patients enrolled in the study. 1,25(OH)₂D₃ preconditioning exacerbated the inhibition of patient-derived melanoma cell growth and motility in comparison to monotherapy with cediranib. A significant decrease in mitochondrial respiration parameters, such as non-mitochondrial oxygen consumption, basal respiration and ATP-linked respiration, was observed. It seems that 1,25(OH)₂D₃ preconditioning enhanced cediranib efficacy via the modulation of mitochondrial bioenergetics. Additionally, 1,25(OH)₂D₃ also decreased the viability and mobility of the BRAF+ patient-derived cells treated with vemurafenib. Interestingly, regardless of the strict selection, cancer-derived fibroblasts (CAFs) became the major fraction of cultured cells over time, suggesting that melanoma growth is dependent on CAFs. In conclusion, the results of our study strongly emphasise that the active form of vitamin D, 1,25(OH)₂D₃, might be considered as an adjuvant agent in the treatment of malignant melanoma.

Low vitamin D and high cholesterol facilitate oral carcinogenesis in 4NQO-induced rat models via regulating glycolysis

OBJECTIVES

Diets and nutritional habits are critical during carcinogenic processes, where a diet poor in fruits and vegetables and rich in meat and other foods of animal origin facilitates carcinogenesis. In this study, we aimed at investigating the possible involvement of vitamin D deficiency (VDD) and high cholesterol (HC) together in oral squamous cell carcinoma (OSCC) through modulating glycolysis.

SUBJECTS AND METHODS

We compared total cholesterol, LDL, HDL, triglycerides, LDH, and vitamin D levels of OSCC patients and control individuals. We used GEO datasets for gene set enrichment and 4-nitroquinoline-1-oxide induced in vivo oral carcinogenesis models to investigate contribution of VDD and HC during carcinogenesis via possible modulation of glycolysis.

RESULTS

We found that VDD and HC co-exist in OSCC patients, and deregulation of cholesterol and vitamin D levels results in enrichment of genes related to glycolysis. We, then, demonstrated that VDD and HC on their own and together facilitated the formation of larger tumors in 4NQO-induced in vivo cancer models, which are suppressed by glycolysis inhibition.

CONCLUSION

We reported collaborative contribution of HC and VDD during oral carcinogenesis, which is mainly carried out via altering energy metabolism in tumor cells.

The Taq 1 polymorphism of Vitamin D receptor gene is associated with oral cancer and preoral cancer in North Indian population

BACKGROUND

Oral cancer is known as one of the most common cancers, with a poor prognosis, related to delayed clinical diagnosis, either due to the lack of particular biomarkers related to the disease or costly therapeutic alternatives.

AIMS AND OBJECTIVES

In this study association of single nucleotide polymorphism (Taq1, T>C) in Vitamin D receptor gene with oral cancer and pre oral cancer was studied.

MATERIALS AND METHODS

Total 230 patients of precancerous oral lesions (Leukoplakia 70, Oral Sub mucous fibrosis 90, Lichen Planus 70), 72 oral cancer patients and 300 healthy control subjects were genotyped by PCR-RFLP methods. Chi-square test was used for calculation of genotype and allele frequencies.

RESULTS

Mutant genotype CC as well as C allele were found to significantly decrease the risk of oral disease (P value=0.04, OR=0.60 and P value=0.02, OR=0.75 respectively). In particular, compared to non smokers, smokers with TC & CC genotypes were at decrease risk of oral diseases (P value=0.0001, OR=0.04). The mutant allele genotype CC as well as the mutant allele C showed protective association with leukoplakia (P value=0.01, OR=0.39 & P value=0.009, OR=0.59 respectively). However, individual with CC genotype had developed high cell differentiated grade at diagnosis (OR= 3.78, P value= 0.008).

CONCLUSIONS

This study concludes that VDR (Taq1) polymorphism is associated with oral cancer and pre oral cancer susceptibility in North Indian population.

Vitamin D Deficiency in Both Oral and Systemic Manifestations in SARS-CoV-2 Infection: Updated Review

The specialized literature emphasizes the fact that vitamin D has a potentially beneficial effect in the context of the current COVID-19 pandemic. The purpose of this article is to highlight the role of vitamin D, both prophylactic and curative, in the treatment of patients diagnosed with COVID-19. Even though its relevance is still unknown and causes various controversies, there is currently no specific treatment for patients diagnosed with COVID-19. There are various prevention strategies with new vaccination schedules, but additional randomized and clinical trials are still needed to combat this pandemic. In addition to the systemic manifestations of SARS-CoV-2 infection, oral manifestations of this disease have also been described in the literature. The etiology of oral manifestations associated with COVID-19 infection and vitamin D deficiency remains controversial. In the present studies, oral manifestations such as salivary gland infections, aphthae, erythema, gingivitis, ulcers, etc. have been reported. This is a new topic, and the prevalence of manifestations is described in only a few studies, which is inconsistent with the number of COVID-19 cases reported since the beginning of the pandemic. The clinical symptomatology in patients with current COVID-19 infection is polymorphic. Whether the oral manifestation is directly caused by SARS-CoV-2 or a secondary manifestation remains an important topic to analyze and discuss.

Effect of Curcumin-Loaded Mesoporous Silica Nanoparticles on the Head and Neck Cancer Cell Line, HN5

Curcumin is an active ingredient isolated from Curcuma longa. It has several pharmacological effects, including anticancer, anti-inflammatory, and antioxidant effects. Due to its low bioavailability, chemical structure instability, and easy oxidation, the application of curcumin has been limited. In this study, to overcome these limitations, curcumin-loaded mesoporous silica nanoparticles (Cur-MSN) were prepared, and the anticancerous effect of Cur-MSNs on head and neck cancer cells, HN5, was investigated. Transmission electron microscopy (TEM) revealed rod-shaped mesoporous nanoparticles with average particle size smaller than 100 nm. Higher cytotoxicity of Cur-MSNs was seen in treated cancer cells compared with free curcumin. The expression of Bcl-2 was significantly reduced in the presence of Cur-MSNs compared to the control (untreated HN5 cells) (p < 0.05). A 3.43-fold increase in the Bax/Bcl-2 ratio was seen in Cur-MSNs treated HN5 cells at the IC50. Cur-MSNs increased intracellular reactive oxygen species (ROS) production. Based on these novel results, we suggest that Cur-MSNs offer efficacy for cancer treatment and future studies should further characterize their properties in various experimental cancer models.

Effect of Short-term Vitamin D Supplementation on the Alterations of Glycemic Variables in Response to Exhaustive Eccentric Exercise in Patients with Non-alcoholic Fatty Liver

BACKGROUND: Exhaustive eccentric exercise (EEE), along with a positive role in weight loss and physiological adaptation, increases liver enzymes and disturbs glucose homeostasis. Many studies have been considered to neutralize the adverse effects of EEE, including vitamin D (Vit D) supplementation. The present study aimed to investigate the effect of short-term Vit D supplementation on the alteration of glycemic variables in response to EEE in patients with non-alcoholic fatty liver disease (NAFLD). METHODS: In this clinical trial, 22 overweight women with NAFLD were randomly assigned to control (C; n=11) and experimental (Exp; n=11) groups. C group received a lactose placebo daily with the same color, shape, and warmth percentage; Exp group received 2000 IU of Vit D daily for 6 weeks (42 days). Blood samples were taken to measure the liver enzymes, lipid profile, and Vit D levels alteration at four stages: Pre1(before the first EEE session), post 1 (after the first EEE session), pre 2 (before the second EEE session), and post 2 (after the second EEE session). Repeated measures ANOVA and independent t test were used to analyze the data using SPSS software (version 26) at a significance level of P < 0.05. RESULTS: The results show a significant increase in glucose, insulin, and homeostatic model assessment for insulin resistance (HOMA-IR) levels in both C and Exp groups following the EEE (comparing pre 1 and post 1). Also, after 6 weeks of Vit D supplementation, glucose, insulin, and HOMA-IR increased significantly in both C (P = 0.001, P = 0.001, and P = 0.001, respectively) and Exp (P = 0.001, P = 0.001, and P = 0.001, respectively) groups following EEE (comparison of pre 2 and post 2). However, these increases were significantly lower in Exp group compared with the C group (comparing post 2). CONCLUSION: Short-term Vit D supplementation downregulates the increased glucose, insulin, and insulin resistance induced by EEE in patients with NAFLD.

Identification of Biomarkers Associated with Cancerous Change in Oral Leukoplakia Based on Integrated Transcriptome Analysis

Objective

Oral leukoplakia (OLK) is the most common precancerous lesion in the oral cavity. This study aimed to explore key biomarkers for monitoring OLK for early diagnosis of oral squamous cell carcinoma (OSCC) and screen small-molecule drugs for the prevention of OSCC.

Method

The Gene Expression Omnibus (GEO) database was explored to extract two microarray datasets, namely, GSE85195 and GSE25099. The data of the normal group, OLK group, and OSCC group were analyzed by weighted gene coexpression network analysis (WGCNA) to identify the most significant gene module and differentially expressed genes (DEGs). The intersection genes were extracted as the key genes of OLK carcinogenesis. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were analyzed in the module. Connectivity Map and molecular docking were used to screen small-molecule drugs. The diagnostic values of four key genes were identified and verified in the GSE26549 dataset.

Results

WGCNA obtained the red module (r = −0.91, p < 0.05) with the strongest correlation with cancerous phenotype. GO enrichment analysis showed 60 pathways, including 28 biological processes, 11 cell components, and 21 molecular functions, and KEGG enrichment analysis showed 4 pathways (p < 0.05). In the differential expression analysis, there was no intersection between the upregulated genes and the red module genes. However, the intersection of the downregulated genes and the red module genes yielded 4 key genes: dopachrome tautomerase (DCT), keratin 3 (KRT3), keratin 76 (KRT76), and FAM3 metabolic regulation signal molecule B (FAM3B). The area under the curve of the diagnostic model constructed by these four genes was 0.963 (CI = 0.913–1.000). The sensitivity was 0.933, and the specificity was 0.923. The diagnostic model was successfully verified in GSE26549 (AUC = 0.745, CI = 0.638–0.851). Compared with the diagnostic models of the previous studies, the diagnostic efficiency of this model was the highest. The small-molecule drugs, selumetinib and benidipine, were selected according to the gene expression profile and showed binding activity when docking with the above molecules.

Conclusions

This study provides new targets and drugs for OLK. These targets could be used as the key diagnostic molecules for long-term follow-up of OLK. The small-molecule drugs selumetinib and benidipine could be used for the prevention and treatment of OSCC.

Vitamin D and Its Role in Oral Diseases Development. Scoping Review

Vitamin D is a fat-soluble secosteroid that plays a significant role in the whole body, including the maxillofacial region. The discovery of its receptors in many cells and organs made it possible to reveal the participation of vitamin D not only in the regulation of calcium phosphate metabolism, but also in immune processes, in providing anti-inflammatory and antimicrobial effects, slowing down cell proliferation and stimulating differentiation. In this literature review, we demonstrate the association between low vitamin D levels and the development of recurrent aphthous stomatitis, the course and response to treatment of squamous cell carcinoma of the oral cavity, the severity of periodontal diseases, and the processes of osseointegration and bone remodeling during dental implantation and guided tissue regeneration. The aim of our article was to demonstate a possible connection between vitamin D level and the oral diseases that can be presented at an oral surgery appointment, which will help clinicians to reduce the risk of early dental implant failure, ensure favorable outcomes of augmentative operations, as well as decrease the destructive effects of severe periodontitis and other conditions throug knowledge and timely lab tests and endocrinologist prescriptions.

Serum 25-hydroxyvitamin D is negatively associated with severe periodontitis: a cross-sectional study

BACKGROUND

Periodontitis can lead to the destruction of periodontium and adversely influence the overall health, wellbeing, and quality of life. However, studies on the relationship between severe periodontitis and serum 25-hydroxyvitamin D [25(OH)D] are limited. This study is designed to explore the relationship between 25(OH)D and severe periodontitis.

METHODS

A cross-section study of 2928 participants enrolled from the National Health and Nutrition Examination Survey (NHANES) from 2013 to 2014 was conducted. The periodontal examination was performed using a total oral periodontal examination program, and probe measurements were collected at six sites per tooth in NHANES. Severe periodontitis was characterized as: ≥ 2 interproximal sites with attachment loss (AL) ≥ 6 mm (not on the same tooth) and ≥ 1 interproximal site with probing depth (PD) ≥ 5 mm. Severe periodontitis and serum 25(OH)D were the dependent and independent variables, respectively. Univariate, multivariate, and subgroup analyses were performed to explore the relationship between severe periodontitis and serum 25(OH)D.

RESULTS

Among the 2928 participants, the average age of the population was 50 ± 13.71 years old, with 1425 (48.67%) males, 316 (10.79%) exhibited severe periodontitis. Serum 25(OH)D showed a significantly negative association with severe periodontitis after adjusting all variables (OR 0.75, 95% CI 0.63-0.89). In addition, severe periodontitis has a nonlinear relationship with serum 25(OH)D, whoes inflection point was 102 (nmol/L). On the left side of the inflection point (25(OH)D ≤ 102 nmol/L), the effect size was 0.98 and 95%CI was 0.98-0.99 (25(OH)D per 1 nmol/L increments). On the right side of the inflection point (25(OH)D > 102 nmol/L), the effect size was 0.99 and 95% CI was 0.98-1.01. The subgroup analysis showed pronounced changes in non-Hispanic white, alcohol consumption, diabetes, and health insurance.

CONCLUSION

Serum 25 (OH) D in relation to severe periodontitis is nonlinear in our study.When serum 25 (OH) D is less than 102 nmol/L, serum 25 (OH) D is negatively associated with severe periodontitis.

Role of vitamin D/VDR nuclear translocation in down-regulation of NF-κB/NLRP3/caspase-1 axis in lupus nephritis

BACKGROUND

Vitamin D receptor (VDR) and NLRP3 inflammasome play critical roles in lupus nephritis (LN) pathogenesis.

AIM OF THE STUDY

This study explored the therapeutic effect of VDR agonist on LN and its molecular mechanism to inhibit NLRP3 signalling.

METHODS

C57BL/6 mice, lupus-prone MRL/lpr mice, and VDR agonist paricacitol-treated MRL/lpr mice (300 ng/kg/mouse per dose, 5 times/week for 8 weeks from 8 weeks old) were used to assess kidney histopathology and measure proteinuria, serum anti-ds-DNA antibody and expression of NF-κB/NLRP3/caspase-1/IL-1β/IL-18 axis. We used mouse renal tubular epithelial cells (mRTECs) to identify protein-protein interactions and examine the effects of paricalcitol.

RESULTS AND CONCLUSION

LN pathogenesis decreased after paricalcitol treatment. We observed a marked improvement in renal pathology and a time-dependent decrease urine protein and serum anti-dsDNA antibody levels. In 16-week-old MRL/lpr LN mice, the upregulated expression of NLRP3/caspase-1/IL-1β/IL-18 axis was significantly downregulated after paricalcitol treatment. Paricalcitol can reverse the apoptosis induced by anti-dsDNA antibody via the NF-κB/NLRP3/caspase-1/IL-1β/IL-18 axis in mRTECs. Furthermore, paricalcitol suppressed NF-κB nuclear translocation by competitively binding to importin-4. In summary, the VDR agonist can alleviate LN by modulating the NF-κB/NLRP3/caspase-1/IL-1β/IL-18 axis and suppressing the NF-κB nuclear translocation.

Increased integrity of cell-cell junctions accompanied by increased expression of claudin 4 in keratinocytes stimulated with vitamin D3

The stratified squamous epithelium has a multilayer structure formed by the differentiation of the keratinized epithelium, which covers the skin and oral mucosa. The epithelium plays a central role in regulating the interactions between the immune system and pathogens. The tight junction (TJ) barrier, which is composed of adhesion molecules called claudins (CLDN), is critical for the homeostasis of the skin and oral mucosa. Furthermore, the crucial roles of vitamin D3 (VD3) in the pathogeneses of skin and oral mucosal disease have been suggested. The aim of this in vitro study was to observe the correlations between the integrity of the keratinocyte population and the expression levels of CLDN1 and CLDN4 in gingival epithelial cells, stimulated with VD3. CLDN 1 and 4 expression levels were down and upregulated, respectively, in the cells stimulated with VD3. Additionally, transepithelial electrical resistance (TEER) levels were increased in the stimulated cells when compared to the controls. These findings indicate that CLDN 4 may play a more important role in the TJ barrier than CLDN 1. Hence, the therapeutic effect of VD3 in skin and oral diseases may be regulated by the increase in the expression of CLDN 4.

Early Osteogenic Differentiation Stimulation of Dental Pulp Stem Cells by Calcitriol and Curcumin

Curcumin, as a natural phenolic substance, is extracted from the rhizome of Curcuma longa (turmeric), which is effective in bone healthfulness. Calcitriol is an effective hormone in regulating bone remodeling and mineral homeostasis and immune response. Mesenchymal stem cells (MSCs) are found in most dental tissues and resemble bone marrow-derived MSCs. In this work, we investigated the effect of combination and individual treatment of curcumin and calcitriol on early osteogenic differentiation of dental pulp stem cells (DPSCs). Early osteogenic differentiation was evaluated and confirmed by the gene expression level of ALP and its activity. Curcumin individually and in combination with calcitriol increased ALP activity and osteoblast-specific mRNA expression of ALP when DPSCs were cultured in an osteogenic medium. Calcitriol alone increased the enzyme more than in combination with curcumin. These findings demonstrate that curcumin can induce early osteogenic differentiation of DPSCs like calcitriol as a potent stimulant of osteogenesis.

Vitamin D receptor gene polymorphisms and its interactions with environmental factors on renal cell carcinoma risk

Aims

We designed a case-control study to investigate the effect of vitamin D receptor gene (VDR) gene single nucleotide polymorphisms (SNPs) and possible gene- environment interaction on the susceptibility of renal cell carcinoma (RCC).

Methods

Generalized multifactor dimensionality reduction (GMDR) was used to find out the interaction combinations between SNPs and environmental factors, including gene- gene synergy and gene environment synergy effect. Logistic regression was used to analyze the correlation between the four SNPs in VDR gene and RCC, and the significant interaction combinations found by GMDR model were analyzed by hierarchical analysis.

Results

The genotype distribution of the control group was in accordance with Hardy- Weinberg equilibrium. Logistic regression analysis showed that the risk of RCC in VDR-rs7975232 A allele carriers was significantly higher than that of CC genotype carriers (CA + AA vs. CC), adjusted OR (95 % CI) = 1.75 (1.26–2.28). We used GMDR model to screen the best synergistic model between the four SNPs of VDR gene and smoking and drinking. We found a significant two locus model (P = 0.0010) involving rs7975232 and smoking. The cross- validation consistency of the two- locus model was 10/ 10, and the accuracy was 60.72 %. Compared with non-smokers with rs7975232 -CA or AA genotype, smokers with rs7975232 -CC genotype had the highest risk of RCC, or (95 % CI) = 2.23 (1.42–3.09), after adjustment for covariates.

Conclusions

We found that the A allele of rs7975232 within VDR gene, interaction between rs7975232 and smoking were all associated with increased RCC risk.

Nutraceuticals: Transformation of Conventional Foods into Health Promoters/Disease Preventers and Safety Considerations

Nutraceuticals are essential food constituents that provide nutritional benefits as well as medicinal effects. The benefits of these foods are due to the presence of active compounds such as carotenoids, collagen hydrolysate, and dietary fibers. Nutraceuticals have been found to positively affect cardiovascular and immune system health and have a role in infection and cancer prevention. Nutraceuticals can be categorized into different classes based on their nature and mode of action. In this review, different classifications of nutraceuticals and their potential therapeutic activity, such as anti-cancer, antioxidant, anti-inflammatory and anti-lipid activity in disease will be reviewed. Moreover, the different mechanisms of action of these products, applications, and safety upon consumers including current trends and future prospect of nutraceuticals will be included.

Effect of Selected Factors on the Serum 25(OH)D Concentration in Women Treated for Breast Cancer

Maintaining an optimal vitamin D concentration reduces the risk of recurrence and extends survival time in patients after breast cancer treatment. Data on vitamin D deficiency among Polish women after breast cancer therapy are limited. Thus, the aim of the study was the analysis of vitamin D status in post-mastectomy patients, considering such factors as seasons, social habits, vitamin D supplementation and its measurements. The study involved 94 women after breast cancer treatment. Serum vitamin D concentration was measured, and a questionnaire, gathering demographic and clinical data regarding cancer, diet, exposure to sun radiation, and knowledge of recommendations on vitamin D supplementation, was delivered twice, in both winter and in summer. The control group consisted of 94 age-matched women with no oncological history. In women after breast cancer treatment, 25-hydroxyvitamin D (25(OH)D) deficiency was much more frequent than in the general population. Only about half of the patients supplemented vitamin D at the beginning of the study. After the first test and the issuing of recommendations on vitamin D supplementation, the percentage of vitamin D supplemented patients increased by about 30% in study groups. The average dose of supplement also increased. None of the women that were not supplementing vitamin D and were tested again in winter had optimal 25(OH)D concentration. It was concluded that vitamin deficiency is common in women treated for breast cancer. Medical advising about vitamin D supplementation and monitoring of 25(OH)D concentration should be improved.

Oral microbiota and vitamin D impact on oropharyngeal squamous cell carcinogenesis: a narrative literature review

An emerging body of research is revealing the microbiota pivotal involvement in determining the health or disease state of several human niches, and that of vitamin D also in extra-skeletal regions. Nevertheless, much of the oral microbiota and vitamin D reciprocal impact in oropharyngeal squamous cell carcinogenesis (OPSCC) is still mostly unknown. On this premise, starting from an in-depth scientific bibliographic analysis, this narrative literature review aims to show a detailed view of the state of the art on their contribution in the pathogenesis of this cancer type. Significant differences in the oral microbiota species quantity and quality have been detected in OPSCC-affected patients; in particular, mainly high-risk human papillomaviruses (HR-HPVs), Fusobacterium nucleatum, Porphyromonas gingivalis, Pseudomonas aeruginosa, and Candida spp. seem to be highly represented. Vitamin D prevents and fights infections promoted by the above identified pathogens, thus confirming its homeostatic function on the microbiota balance. However, its antimicrobial and antitumoral actions, well-described for the gut, have not been fully documented for the oropharynx yet. Deeper investigations of the mechanisms that link vitamin D levels, oral microbial diversity and inflammatory processes will lead to a better definition of OPSCC risk factors for the optimization of specific prevention and treatment strategies.

Promoter hypermethylation regulates vitamin D receptor (VDR) expression in colorectal cancer-A study from Kashmir valley

BACKGROUND

Colorectal carcinogenesis (CRC) is a multistep process, involving both genetic and epigenetic modifications of genes involved in diverse pathways ranging from tumor suppression to DNA mismatch repair.

PURPOSE

This study was undertaken to assess the role of promoter methylation of vitamin D receptor (VDR) gene, a transcription factor with myriad biological functions, in relation to its expression and clinicopathological parameters.

METHODS

Tissue specimens were taken from a total of 75 colorectal cancer cases paired with their normal surrounding epithelium and analyzed by Real-time RT-PCR for assessing the expression profile and MS-PCR for analyzing the promoter methylation status of the VDR gene. Blood sample from the same patients was drawn for vitamin D estimation.

RESULTS

The frequency of promoter methylation in cancerous tissue was 37.33% against 9.33% in normal tissues (p<0.001). The hypermethylated status of VDR promoter showed significantly inverse association with its expression (p=0.008). Furthermore, when compared with the clinical parameters, methylation status of VDR promoter was significantly associated with tumor staging (p=0.008), grading (p<0.001), depth of invasion (p=0.002) and lymph node metastases (p<0.001). Univariate and multivariate analysis indicated patients with increased VDR expression (p<0.001) and decreased methylation status (p=0.012) exhibited longer overall survival. Additionally, serum 25(OH)D₃ levels were not significantly associated with any of the patient characteristics.

CONCLUSION

Our study, first of its kind from Kashmir, indicated that VDR shows aberrant methylation pattern in CRC with consequent loss in its expression.

Correlations among Pulmonary DJ-1, VDR and Nrf-2 in patients with Chronic Obstructive Pulmonary Disease: A Case-control Study

Parkinson protein 7 (PARK7)/DJ-1 (DJ-1) is a redox sensitive molecular and stabilizer of nuclear factor erythroid 2-related factor 2 (Nrf-2). Nrf-2 regulates the downstream antioxidant defense system and exerts a significant function in patients with chronic obstructive pulmonary disease (COPD). Vitamin D receptor (VDR) is the nuclear receptor that regulates the downstream target genes. This study aimed to analyze the associations among pulmonary function, DJ-1, VDR and Nrf-2 in COPD patients. Serum was collected from 180 COPD patients and control subjects. Thirty-five lung tissues were obtained. DJ-1 was measured using ELISA and western blotting. Nrf-2 and VDR were detected by immunohistochemistry. Serum and pulmonary DJ-1 levels were lower in COPD patients than those in control subjects. Pulmonary VDR-positive nuclei were reduced in COPD patients. Nrf-2-positive nuclei were reduced in lung tissues of COPD patients. On the contrary, Nrf-2-related downstream target proteins were elevated in COPD patients. Further correlation analysis indicated that forced expiratory volume in 1 second (FEV1) was positively associated with pulmonary DJ-1, VDR and Nrf-2 in patients with COPD. In addition, there were positive correlations among DJ-1, VDR and Nrf-2 in lung tissues of COPD patients. In conclusion, DJ-1, VDR and Nrf-2 were decreased in COPD patients compared with control subjects. The reduction of DJ-1 and VDR associating with Nrf-2 downregulation may be involved in the process of COPD.

Association between Vitamin D and Candida-Associated Denture Stomatitis

Candida-associated denture stomatitis (CADS) is a fungal infection affecting 60–65% of denture wearers. Its etiology is complex and multifactorial and often associated with host immunodeficiency. Evidence exists that vitamin D has potential immunomodulatory and anti-inflammatory effects. The aim of this case–control study was to assess the association between vitamin D levels and CADS. The study included 32 complete denture wearers with CADS and 32 sex- and age-matched complete denture wearers without CADS. The patients were clinically examined, and the severity of denture stomatitis was assessed according to Newton’s classification scale. The serum vitamin D level was determined via the use of an electrochemiluminescence assay. The vitamin D level in the CADS group and control group was 54.68 ± 17.07 and 56.82 ± 17.75 nmol/L, respectively. There was no significant difference between the groups (p = 0.622). Univariate logistic regression analysis showed that the presence of CADS was not associated with hypovitaminosis D (odds ratio (OR) = 1.44; 95% confidence interval (CI) = 0.37–5.54). It can be concluded that vitamin D is not associated with CADS and does not play a significant role in host susceptibility to CADS. This finding suggests that vitamin D screening is not indicated routinely in patients with Candida-associated denture stomatitis.

The Relationship Between Serum 25[OH]D Concentration and Orthopaedic Infection: A Case-Control Study

Background

An estimated one in two healthy adults in the United Kingdom suffer from low levels of 25[OH]D. Vitamin D is involved in modulating immune response, but there is less clarity over its role in orthopaedic infection. This study assesses the relationship between serum 25[OH]D concentration and orthopaedic infection.

Methods

A total of 205 patients in a tertiary referral centre for orthopaedic infection were included in the study. They were divided into groups based on their infection status, matched by age and gender. Data were statistically analysed to determine presence and direction of relationship.

Results

A total of 114 patients had an infection. There was no statistically significant difference in age or gender between the two groups. Mean serum 25[OH]D concentration was 39 nmol/L in the group with infection and 59 nmol/L in the group without an infection (p<0.01). Overall mean serum 25[OH]D concentration was 48 nmol/L. There was a correlation between low serum 25[OH]D concentration and rate of infection (odds ratio, 5.94; 95% confidence interval [CI], 3.24 to 10.92) with a bivariate correlation of −0.338 (p<0.01).

Conclusion

This study demonstrates an association between low levels of serum 25[OH]D and increased orthopaedic infection. Orthopaedic inpatients suffered from vitamin D insufficiency, and there was a correlation between higher levels of serum 25[OH]D and lower rates of infection. This suggests that prophylactic supplementation of 25[OH]D may improve outcomes, and provides a foundation for randomized controlled trials to assess its effectiveness in practice.

Modulating effect of vitamin D3 on the mutagenicity and carcinogenicity of doxorubicin in Drosophila melanogaster and in silico studies

Vitamin D3 (VD3) deficiency increases DNA damage, while supplementation may exert a pro-oxidant activity, prevent viral infections and formation of tumors. The aim of this study was to investigate the mutagenicity and carcinogenicity of VD3 alone or in combination with doxorubicin (DXR) using the Somatic Mutation and Recombination Test and the Epithelial Tumor Test, both in Drosophila melanogaster. For better understanding of the molecular interactions of VD3 and receptors, in silico analysis were performed with molecular docking associated with molecular dynamics. Findings revealed that VD3 alone did not increase the frequency of mutant spots, but reduced the frequency of mutant spots when co-administered with DXR. In addition, VD3 did not alter the recombinogenic effect of DXR in both ST and HB crosses. VD3 alone did not increase the total frequency of tumor, but significantly reduced the total frequency of tumor when co-administered with DXR. Molecular modeling and molecular dynamics between calcitriol and Ecdysone Receptor (EcR) showed a stable interaction, indicating the possibility of signal transduction between VD3 and EcR. In conclusion, under these experimental conditions, VD3 has modulatory effects on the mutagenicity and carcinogenicity induced by DXR in somatic cells of D. melanogaster and exhibited satisfactory interactions with the EcR.

Erectsterates A and B, a pair of novel highly degraded steroid derivatives from the South China Sea soft coral Sinularia erecta

Two novel steroidal derivatives, erectsterates A (1) and B (2), a pair of epimers at C-10, were isolated from the South China Sea soft coral Sinularia erecta. Their structures were established by extensive spectroscopic analysis and deduction from biosynthesis route. Compounds 1 and 2 are rare steroids with a highly degradation in ring B and an ester linkage between A and C/D rings, similar with the known compounds chaxines B (3) and D from an edible mushroom Agrocybe chaxingu. To the best of our knowledge, this is the first report of such kind of steroid from soft coral. And a different biosynthetic route from the reported approach of chaxines was proposed in this paper. Interestingly, the ring C of 1 and 2 was formally oxidized by Baeyer-Villiger reaction to provide an unprecedented seven-membered lactone moiety in ring C of steroid. The in vitro anti-proliferative activities of 2 were evaluated against A549, HT-29, SNU-398 and Capan-1 cell lines. The results indicated that it showed weak cytotoxicity against the tested four cell lines.

Vitamin D receptor exhibits different pharmacodynamic features in tumoral and normal microenvironments: A molecular modeling study

The vitamin D receptor (VDR) constitutes a promising therapeutic target for the treatment of cancer. Unfortunately, its natural agonist calcitriol does not have clinical utility due to its potential to induce hypercalcemic effects at the concentrations required to display antitumoral activity. For this reason, the search for new calcitriol analogues with adequate therapeutic profiles has been actively pursued by the scientific community. We have previously reported the obtaining and the biological activity evaluation of new calcitriol analogues by modification of its sidechain, which exhibited relevant antiproliferative and selectivity profiles against tumoral and normal cells. In this work we conducted molecular modeling studies (i.e. molecular docking, molecular dynamics, constant pH molecular dynamics (CpHMD) and free energy of binding analysis) to elucidate at an atomistic level the molecular basis related to the potential of the new calcitriol analogues to achieve selectivity between tumoral and normal cells. Two histidine residues (His305 and His397) were found to exhibit a particular tautomeric configuration that produces the observed bioactivity. Also, different acid-based properties were observed for His305 and His307 with His305 showing an increased acidity (pKa 5.2) compared to His397 (pKa 6.8) and to the typical histidine residue. This behavior favored the pharmacodynamic interaction of the calcitriol analogues exhibiting selectivity for tumoral cells when VDR was modeled at the more acidic tumoral environment (pH ≅ 6) compared to the case when VDR was modeled at pH 7.4 (normal cell environment). On the other hand, non-selective compounds, including calcitriol, exhibited a similar interaction pattern with VDR when the receptor was modeled at both pH conditions. The results presented constitute the first evidence on the properties of the VDR receptor in different physicochemical environments and thus represent a significant contribution to the in silico screening and design of new calcitriol analogues.

Vitamin D Deficiency and Oral Health: A Comprehensive Review

Vitamin D (VD) levels have been gaining growing attention in Oral Health. During growth and adulthood, VD deficiency (VDD) is associated with a wide variety of oral health disorders, and impaired VD synthesis may expedite some of these conditions. In children, severe VDD can induce defective tooth mineralization, resulting in dentin and enamel defects. As a consequence, these defects may increase the risk of the onset and progression of dental caries. Further, VDD has been associated with higher prevalence of periodontitis and gingival inflammation, and several recent preclinical and clinical studies have unveiled potential pathways through which Vitamin D may interact with the periodontium. VDD correction through supplementation may contribute to a successful treatment of periodontitis; however, alveolar bone regeneration procedures performed in baseline VDD patients seem more prone to failure. Vitamin D may also be linked with some oral pathology entities such as certain oral cancers and events of osteonecrosis of the jaw. This review aims to provide comprehensive evidence of how VD levels should be considered to promote good oral health, and to summarize how VDD may hamper oral development and its role in certain oral conditions.

1,25(OH)2D3 Strengthens the Vasculogenesis of Multipotent Mesenchymal Stromal Cells from Rat Bone Marrow by Regulating the PI3K/AKT Pathway

Background

Multipotent mesenchymal stromal cells (MSCs) have recently been reported to promote vasculogenesis by differentiating into endothelial cells and releasing numerous cytokines and paracrine factors. However, due to low cell activity, their potential for clinical application is not very satisfactory. This study aimed to explore the effects and mechanisms of 1,25-dihydroxyvitamin D (1,25(OH)₂D₃) on the vasculogenesis of MSCs.

Methods

MSCs were isolated from the femurs and tibias of rats and characterized by flow cytometry. After treatment with different concentrations of 1,25(OH)₂D₃ (0 µM, 0.1 µM and 1 µM), the proliferation of MSCs was analyzed by Cell Counting Kit-8 (CCK-8), and the migratory capability was measured by Transwell assays and cell scratch tests. Capillary-like structure formation was observed by using Matrigel. Western blotting was used to detect the expression of FLK-1 and vWF to investigate the differentiation of MSCs into endothelial cells. Western blotting and gelatin zymography were used to detect the expression and activities of VEGF, MMP-2 and MMP-9 secreted by MSCs under the influence of 1,25(OH)₂D_3. Finally, the VDR antagonist pyridoxal-5-phosphate (P5P) and the PI3K/AKT pathway inhibitor LY294002 were utilized to test the phosphorylation levels of key kinases in the PI3K/AKT pathway by Western blotting and the formation of capillary-like structures in Matrigel.

Results

The proliferation and migratory capability of MSCs and the ability of MSCs to form a tube-like structure in Matrigel were enhanced after treatment with 1,25(OH)₂D₃. Moreover, MSCs treated with 1,25(OH)₂D₃ showed high expression of vWF and Flk-1. There was a significant increase in the expression of VEGF, MMP-2 and MMP-9 secreted by MSCs treated with 1,25(OH)₂D_3, as well as in the activity of MMP-2 and MMP-9. The phosphorylation level of AKT increased with time after 1,25(OH)₂D₃ treatment, while LY294002 weakened AKT phosphorylation. In addition, the ability to form capillary-like structures was reduced when the VDR and PI3K/AKT pathways were blocked.

Conclusion

This study confirmed that 1,25(OH)₂D₃ treatment can strengthen the ability of MSCs to promote vasculogenesis in vitro, and the mechanism may be related to the activation of the PI3K/AKT pathway.

Identification for Exploring Underlying Pathogenesis and Therapy Strategy of Oral Squamous Cell Carcinoma by Bioinformatics Analysis

BACKGROUND Oral squamous cell carcinoma (OSCC), one of the most common cavity-associated cancers, has a high incidence and worldwide mortality. However, the cause and underlying molecular mechanisms of OSCC remain unclear. MATERIAL AND METHODS Three microarray datasets (GSE23558, GSE34105, and GSE74530) from the Gene Expression Omnibus (GEO) database were downloaded and then integrated to gain differentially expressed genes (DEGs). We performed Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichments of DEGs in order to elucidate DEGs' biological roles. Protein-protein interaction (PPI) networks were established in order to identify hub genes. To validate the gene markers for OSCC, the data of TCGA OSCC were also assessed. RESULTS Together, 651 DEGs containing 288 upregulated genes and 363 downregulated genes were screened out, which could completely distinguish between OSCC and normal control tissues by principal component analysis (PCA). The GO analysis indicated the DEGs were enriched in chemokine activity in the biological process group. The molecular functions of DEGs included growth factor activity. The molecular functions included oxidoreductase activity. The main DEG-associated cellular components included extracellular exosome. The KEGG pathway analysis indicated the DEGs were mainly participated in the cytokine-cytokine receptor interaction, metabolism of xenobiotics by cytochrome P450 and glutathione metabolism signal pathway. The co-expression network identified core genes from the PPI network. Additionally, Kaplan-Meier survival analysis showed that CSF2 and EGF genes were significantly correlated with OSCC patients' overall survival. CONCLUSIONS Our study using an integrated bioinformatics analysis might provide valuable information for exploring potential new molecular biomarkers and therapeutic targets for OSCC.

Integration of microbiology, molecular pathology, and epidemiology: a new paradigm to explore the pathogenesis of microbiome-driven neoplasms

Molecular pathological epidemiology (MPE) is an integrative transdisciplinary field that addresses heterogeneous effects of exogenous and endogenous factors (collectively termed 'exposures'), including microorganisms, on disease occurrence and consequences, utilising molecular pathological signatures of the disease. In parallel with the paradigm of precision medicine, findings from MPE research can provide aetiological insights into tailored strategies of disease prevention and treatment. Due to the availability of molecular pathological tests on tumours, the MPE approach has been utilised predominantly in research on cancers including breast, lung, prostate, and colorectal carcinomas. Mounting evidence indicates that the microbiome (inclusive of viruses, bacteria, fungi, and parasites) plays an important role in a variety of human diseases including neoplasms. An alteration of the microbiome may be not only a cause of neoplasia but also an informative biomarker that indicates or mediates the association of an epidemiological exposure with health conditions and outcomes. To adequately educate and train investigators in this emerging area, we herein propose the integration of microbiology into the MPE model (termed 'microbiology-MPE'), which could improve our understanding of the complex interactions of environment, tumour cells, the immune system, and microbes in the tumour microenvironment during the carcinogenic process. Using this approach, we can examine how lifestyle factors, dietary patterns, medications, environmental exposures, and germline genetics influence cancer development and progression through impacting the microbial communities in the human body. Further integration of other disciplines (e.g. pharmacology, immunology, nutrition) into microbiology-MPE would expand this developing research frontier. With the advent of high-throughput next-generation sequencing technologies, researchers now have increasing access to large-scale metagenomics as well as other omics data (e.g. genomics, epigenomics, proteomics, and metabolomics) in population-based research. The integrative field of microbiology-MPE will open new opportunities for personalised medicine and public health. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.