Is 1,25-dihydroxyvitamin D3 receptor expression a potential Achilles’ heel of CD44+ oral squamous cell carcinoma cells?

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.

Serum levels of 25-hydroxy-vitamin D in patients with oral squamous cell carcinoma: Making a case for chemoprevention

Objectives

Serum level of vitamin D has been used as a predictor for cancer development. We intend to measure the baseline vitamin D level in patients with oral squamous cell carcinoma (OSCC) and to compare same with non‐cancer controls to determine any association.

Materials and methods

Patients with OSCC presenting to our clinics were included in this study. Their baseline serum vitamin D levels were measured prior to cancer treatment after obtaining their consents. These patients were then matched with at least 2 cancer‐free subjects to serve as controls and whose serum vitamin D levels were also measured. The serum vitamin D levels obtained for the two groups were then categorized into normal (>35 ng/ml), mild deficiency (25–35 ng/ml), moderate deficiency (12.5–25 ng/ml), and severe deficiency (<12.5 ng/ml). The data were analyzed statistically and the two groups compared.

Results

A total of 51 patients with OSCC (Male 22 [43%] and female 29 [57%]) and 113 cancer‐free controls (Male 36 [31.86%] and female 77 [68.14%]) were included in the study. The commonest site for OSCC was the tongue, accounting for 45% of the cancer cases. Mean age for cancer patients was 59.33 years ±12.54 and 49.24 years ±15.79 for the control. Among the OSCC patients, 74.51% had moderate to severe vitamin D deficiencies, whereas only 20.35% had a moderate deficiency in the control group with no severe deficiency.

Conclusion

Logistic regression analysis shows a positive association between vitamin D deficiency and OSCC risk especially in levels below 25 ng/ml. This further corroborates the assertion that vitamin D deficiency may be a useful indicator of OSCC. It may, therefore, be necessary to routinely prescribe vitamin D supplements to subjects with moderate to severe deficiencies in order to decrease the chances of OSCC development.

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

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. Vitamin D executes its functions by interacting with the vitamin D receptor (VDR), both in healthy and diseased individuals, including oral cancer. This review discusses the role of vitamin D and VDR on tumorigenesis, emphasizing on oral cancer. Furthermore, regulation of VDR expression, mechanisms of anticancer effects of calcitriol, oral cancer chemoresistance and its relation with VDR and polymorphisms of VDR gene will be discussed. The manuscript is prepared mainly using the information collected from PubMed and MEDLINE.

Expression of SOX2 in oral squamous cell carcinoma and the association with lymph node metastasis

Oral squamous cell carcinomas (OSCCs) are a growing problem in the world. The various existing treatments have not markedly improved the survival rate of patients with OSCC during the past three decades. Novel treatment strategies are required. Sex determining region Y-box 2 (SOX2) is a transcription factor that is involved in the maintenance of embryonic stem cell pluripotency and in multiple developmental processes. SOX2 expression was indicated to act as a prognostic factor in various types of tumors, including breast, colorectal, gastric and lung cancer and glioblastoma, and as a link between malignancy and stemness. Cancer stem cells (CSCs) may be responsible for the genesis, growth and metastatic spread of tumors. The poor survival outcomes for OSCC patients may be attributable to a poor selection of target cells for treatment, as current oral cancer therapies are generally aimed at the global mass of tumor. Therefore, the consideration that novel approaches to oral cancer may be targeted using SOX2 and CSCs appears reasonable. In order to better understand the oncogenic roles and the corresponding signal transduction pathways of the SOX2 protein, the present study emphasizes the role of SOX2 in OSCC, including the proteins associated with OSCC, and reviews the literature regarding the role of SOX2 in lymph node metastasis. The aim of the present study is to provide a reference for future studies that engage in research on the aforementioned subject.

Serum vitamin D levels of patients with oral squamous cell carcinoma (OSCC) and expression of vitamin D receptor in oral precancerous lesions and OSCC

Background: Resistance to programmed cell death (apoptosis) is a crucial factor for the carcinogenesis of oral squamous cell carcinoma (OSCC). Vitamin D (calcitriol) may overcome apoptosis resistance in tumor cells of OSCC. Vitamin D receptor (VDR) expression in oral precancerous lesions of OSCC has not been analyzed and serum vitamin D level seems to be a predictor of cancer development. Material and Methods: Expression of VDR was analyzed in normal oral mucosa (n=5), oral precursor lesions (simple hyperplasia, n=11; squamous intraepithelial neoplasia, SIN I-III, n=35), and OSCC specimen (n=42) by immunohistochemistry (IHC). Moreover, serum vitamin D levels were measured by 25(OH)D3 (calcidiol) in patients with OSCC (n=42) and correlated with IHC results. Results: Expression of VDR was significantly increased in precancerous and OSCC compared with normal tissue. Compared with SIN I-III lesions VDR expression significantly decreased in OSCC. Severe vitamin D deficiency was detected in our OSCC patient cohort but there was no significant correlation analyzed between serum vitamin D levels and corresponding immunohistochemically detected VDR expression in OSCC. Conclusions: Our survey provides the first evidence of VDR expression in precancerous lesions of OSCC. Apoptosis induction of VDR+ cells in oral precancerous lesions and OSCC by natural vitamin D or synthetic vitamin D compounds could be useful for chemoprevention. Moreover, systemically and/or locally applied, these compounds may act as sensitizers for apoptosis mediated by radio-, and chemotherapy treatment in OSCC.

Key words:Oral cancer, oral precancer, lichen planus, leukoplakia, apoptosis, serum 25(OH)D3, vitamin D receptor, chemoprevention, multistep carcinogenesis.

Vitamin D receptor expression is associated with improved overall survival in human glioblastoma multiforme

Vitamin D and its analogs have been shown to display anti-proliferative effects in a wide variety of cancer types including glioblastoma multiforme (GBM). These anticancer effects are mediated by its active metabolite, 1α, 25-dihydroxyvitamin D3 (calcitriol) acting mainly through vitamin D receptor (VDR) signaling. In addition to its involvement in calcitriol action, VDR has also been demonstrated to be useful as a prognostic factor for some types of cancer. However, to our knowledge, there are no studies evaluating the expression of VDR protein and its association with outcome in gliomas. Therefore, we investigated VDR expression by using immunohistochemical analysis in human glioma tissue microarrays, and analyzed the association between VDR expression and clinico-pathological parameters. We further investigated the effects of genetic and pharmacologic modulation of VDR on survival and migration of glioma cell lines. Our data demonstrate that VDR is increased in tumor tissues when compared with VDR in non-malignant brains, and that VDR expression is associated with an improved outcome in patients with GBM. We also show that both genetic and pharmacologic modulation of VDR modulates GBM cellular migration and survival and that VDR is necessary for calcitriol-mediated effects on migration. Altogether these results provide some limited evidence supporting a role for VDR in glioma progression.

Vitamin D receptor and CD86 expression in the skin of vitamin D-deficient swine

The immunomodulatory role of vitamin D in many diseases is well established. However, the relationship between vitamin D status and skin cancers is unclear. In this study, we examined the effect of vitamin D deficiency and sufficiency on VDR, NF-κB, and CD86 in the epidermis of Yucatan microswine tragi. All of these proteins have known roles in the pathogenesis of cutaneous malignancies such as melanoma and non-melanoma skin cancer. There was weaker and less discrete nuclear staining for VDR and weaker CD86 immunoreactivity with patchy membranous expression in the epidermis of vitamin D-deficient compared to vitamin D-sufficient swine. There was no difference in the immunostaining for NF-κB. Since VDR and CD86 expression are decreased in the setting of melanoma and non-melanoma skin cancers, our findings suggest a potential role of vitamin D-deficiency in the progression of skin malignancies.