Crosstalk Between Vitamin D and p53 Signaling in Cancer: An Update

Impact of Vitamin D on Skin Aging, and Age-Related Dermatological Conditions

Human skin is a physical and biochemical barrier that protects the internal body from the external environment. Throughout a person's life, the skin undergoes both intrinsic and extrinsic aging, leading to microscopic and macroscopic changes in its morphology. In addition, the repair processes slow with aging, making the older population more susceptible to skin diseases. Intrinsic factors associated with advanced age gradually degrade the dermal collagen matrix, resulting in fine wrinkles and reduced elasticity; this is accelerated in post-menopausal women due to estrogen deficiency. In contrast, extrinsic factors associated with advanced age, primarily caused by exposure to ultraviolet (UV) radiation, lead to coarse wrinkles, solar elastosis, hyperkeratosis, irregular pigmentation, and skin cancers. UVB radiation, while contributing to skin photo-aging, also induces the cutaneous synthesis of vitamin D. Vitamin D, in turn, protects the skin from oxidative stress, inflammation, and DNA damage, thereby delaying both chronological and photo-aging. Moreover, research has demonstrated an association between lower vitamin D levels and a higher prevalence of certain cutaneous diseases. This review explores and summarizes the critical role of vitamin D in skin aging and age-related skin diseases. The data presented highlight the importance of maintaining vitamin D adequacy throughout life.

Biochemical mechanisms and molecular interactions of vitamins in cancer therapy

Recently, the potential role of vitamins in cancer therapy has attracted considerable research attention. However, the reported findings are inconsistent, with limited information on the biochemical and molecular interactions of different vitamins in various cancer cells. Importantly, the presence of vitamin receptors in tumor cells suggests that vitamins play a significant role in the molecular and biochemical interactions in cancers. Additionally, studies on the efficacy of vitamin supplementation and dosage levels on tumor progression and mortality risk have yielded inconsistent results. Notably, molecular and biochemical investigations have reported the function of vitamins in the proliferation, growth, and invasiveness of tumor cells, as well as in cell cycle arrest and inflammatory signaling. Additionally, different vitamins may regulate the cancer microenvironment by activating various molecular pathways. Vitamins significantly affect immunological function, antioxidant defense, inflammation, and epigenetic control, and can improve treatment outcomes by affecting cell behavior and combating stress and DNA damage. However, further research is necessary to confirm the efficacy of vitamins, establish ideal dosages, and develop effective cancer prevention and treatment plans. Individualized supplementation plans guided by medical knowledge are crucial to achieving optimal results in clinical and preclinical settings. In this review, we critically evaluated the effects of different vitamins on the risk and development of cancer. Additionally, we examined the potential of vitamin supplements to enhance the efficacy of drug therapy and counteract resistance mechanisms that often arise during cancer treatment.

Vitamin D Significantly Inhibits Carcinogenesis in the Mogp-TAg Mouse Model of Fallopian Tube Ovarian Cancer

Epidemiological and observational studies suggest that vitamin D has potential for the chemoprevention of ovarian cancer. The anticancer effect of vitamin D in the fallopian tube epithelium (FTE), which is now thought to harbor the precursor cells for high grade ovarian cancer, is not known. The purpose of this study was to investigate whether vitamin D can inhibit carcinogenesis in the mogp-TAg fallopian tube (FT) ovarian cancer mouse model and examine underlying mechanisms. To test this hypothesis, 3 groups of 40 5-week-old female mogp-TAg mice were divided equally into two cohorts of 20 mice, treated with either vehicle (vitamin D solvent) or the active 1,25(OH)2D3 analogue EB1089, delivered via mini-pump or IP injection or cholecalciferol delivered in the feed. The FTs were characterized histologically and pathologically after 3 and 7 weeks of treatment. The effect of vitamin D on cultured human FTE cells was also examined. After 3 weeks, vitamin D, delivered as either cholecalciferol or EB1089 significantly inhibited FT carcinogenesis. After 7 weeks, cholecalciferol significantly reduced p53 signatures, serous tubal epithelial carcinoma, FT cancer, and plasma CA125 while increasing apoptosis in the FTE. EB1089 had no significant effect on FT carcinogenesis at 7 weeks. Cholecalciferol significantly reduced proliferation and increased apoptosis in vitro in p53-altered FTE cells. In conclusion, vitamin D inhibited FT carcinogenesis by clearing cells with p53 alterations. These data suggest that vitamin D has merit for the chemoprevention of fallopian tube/ovarian cancer. The optimal chemopreventive effect may be dependent on the route of vitamin D administration.

Vitamin D and cancer

The role of vitamin D in the prevention of chronic diseases including cancer, has received a great deal of attention during the past few decades. The term "Cancer" represents multiple disease states with varying biological complexities. The strongest link between vitamin D and cancer is provided by ecological and studies like observational, in preclinical models. It is apparent that vitamin D exerts diverse biological responses in a tissue specific manner. Moreover, several human factors could affect bioactivity of vitamin D. The mechanism(s) underlying vitamin D initiated anti-carcinogenic effects are diverse and includes changes at the muti-system levels. The oncogenic environment could easily corrupt the traditional role of vitamin D or could ensure resistance to vitamin D mediated responses. Several researchers have identified gaps in our knowledge pertaining to the role of vitamin D in cancer. Further areas are identified to solidify the role of vitamin D in cancer control strategies.

Protective effects of activated vitamin D receptor on radiation-induced intestinal injury

Radiation-induced intestinal injury (RIII) is a common complication after radiation therapy in patients with pelvic, abdominal, or retroperitoneal tumours. Recently, in the model of DSS (Dextran Sulfate Sodium Salt) -induced intestinal inflammatory injury, it has been found in the study that transgenic mice expressing hVDR in IEC (Intestinal Epithelial Cell) manifest highly anti-injury properties in colitis, suggesting that activated VDR in the epithelial cells of intestine may inhibit colitis by protecting the mucosal epithelial barrier. In this study, we investigated the effect of the expression and regulation of VDR on the protection of RIII, and the radiosensitivity in vitro experiments, and explored the initial mechanism of VDR in regulating radiosensitivity of IEC. As a result, we found that the expression of VDR in intestinal tissues and cells in mice can be induced by ionizing radiation. VDR agonists are able to prolong the average survival time of mice after radiation and reduce the radiation-induced intestinal injury. For lack of vitamin D, the radiosensitivity of intestinal epithelial cells in mice increased, which can be reduced by VDR activation. Ensuing VDR activation, the radiation-induced intestinal stem cells damage is decreased, and the regeneration and differentiation of intestinal stem cells is promoted as well. Finally, on the basis of sequencing analysis, we validated and found that VDR may target the HIF/PDK1 pathway to mitigate RIII. We concluded that agonism or upregulation of VDR expression attenuates radiation-induced intestinal damage in mice and promotes the repair of epithelial damage in intestinal stem cells.

Neuroendocrine signaling in the skin with a special focus on the epidermal neuropeptides

The skin, which is comprised of the epidermis, dermis, and subcutaneous tissue, is the largest organ in the human body and it plays a crucial role in the regulation of the body's homeostasis. These functions are regulated by local neuroendocrine and immune systems with a plethora of signaling molecules produced by resident and immune cells. In addition, neurotransmitters, endocrine factors, neuropeptides, and cytokines released from nerve endings play a central role in the skin's responses to stress. These molecules act on the corresponding receptors in an intra-, juxta-, para-, or autocrine fashion. The epidermis as the outer most component of skin forms a barrier directly protecting against environmental stressors. This protection is assured by an intrinsic keratinocyte differentiation program, pigmentary system, and local nervous, immune, endocrine, and microbiome elements. These constituents communicate cross-functionally among themselves and with corresponding systems in the dermis and hypodermis to secure the basic epidermal functions to maintain local (skin) and global (systemic) homeostasis. The neurohormonal mediators and cytokines used in these communications regulate physiological skin functions separately or in concert. Disturbances in the functions in these systems lead to cutaneous pathology that includes inflammatory (i.e., psoriasis, allergic, or atopic dermatitis, etc.) and keratinocytic hyperproliferative disorders (i.e., seborrheic and solar keratoses), dysfunction of adnexal structure (i.e., hair follicles, eccrine, and sebaceous glands), hypersensitivity reactions, pigmentary disorders (vitiligo, melasma, and hypo- or hyperpigmentary responses), premature aging, and malignancies (melanoma and nonmelanoma skin cancers). These cellular, molecular, and neural components preserve skin integrity and protect against skin pathologies and can act as "messengers of the skin" to the central organs, all to preserve organismal survival.

The role of vitamin D on redox regulation and cellular senescence

Vitamin D is considered an essential micronutrient for human health that is metabolized into a multifunctional secosteroid hormone. We can synthesize it in the skin through ultraviolet B (UVB) rays or acquire it from the diet. Its deficiency is a major global health problem that affects all ages and ethnic groups. Furthermore, dysregulation of vitamin D homeostasis has been associated with premature aging, driven by various cellular processes, including oxidative stress and cellular senescence. Various studies have shown that vitamin D can attenuate oxidative stress and delay cellular senescence, mainly by inducing the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and Klotho and improving mitochondrial homeostasis, proposing this vitamin as an excellent candidate for delaying aging. However, the mechanisms around these processes are not yet fully explored. Therefore, in this review, the effects of vitamin D on redox regulation and cellular senescence are discussed to propose new lines of research and clinical applications of vitamin D in the context of age-related diseases.

Ligand-Independent Actions of the Vitamin D Receptor: More Questions Than Answers

Our predominant understanding of the actions of vitamin D involve binding of its ligand, 1,25(OH)D, to the vitamin D receptor (VDR), which for its genomic actions binds to discrete regions of its target genes called vitamin D response elements. However, chromatin immunoprecipitation‐sequencing (ChIP‐seq) studies have observed that the VDR can bind to many sites in the genome without its ligand. The number of such sites and how much they coincide with sites that also bind the liganded VDR vary from cell to cell, with the keratinocyte from the skin having the greatest overlap and the intestinal epithelial cell having the least. What is the purpose of the unliganded VDR? In this review, I will focus on two clear examples in which the unliganded VDR plays a role. The best example is that of hair follicle cycling. Hair follicle cycling does not need 1,25(OH)₂D, and Vdr lacking the ability to bind 1,25(OH)₂D can restore hair follicle cycling in mice otherwise lacking Vdr. This is not true for other functions of VDR such as intestinal calcium transport. Tumor formation in the skin after UVB radiation or the application of chemical carcinogens also appears to be at least partially independent of 1,25(OH)₂D in that Vdr null mice develop such tumors after these challenges, but mice lacking Cyp27b1, the enzyme producing 1,25(OH)₂D, do not. Examples in other tissues emerge when studies comparing Vdr null and Cyp27b1 null mice are compared, demonstrating a more severe phenotype with respect to bone mineral homeostasis in the Cyp27b1 null mouse, suggesting a repressor function for VDR. This review will examine potential mechanisms for these ligand‐independent actions of VDR, but as the title indicates, there are more questions than answers with respect to this role of VDR. © 2021 The Author. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Vitamin D: Promises on the Horizon and Challenges Ahead for Fighting Pancreatic Cancer

Simple Summary

Pancreatic cancer is an almost universally lethal cancer, largely due to its late diagnosis, early metastasis, and therapeutic resistance. This highlights the need to develop novel and effective intervention strategies to improve the outcomes of patients with pancreatic cancer. Vitamin D is one of the hottest topics in cancer research and clinics because of its pleiotropic functions on the hallmarks of cancer. Here we critically review past and current efforts that define the effects of vitamin D on the risk, incidence, patient survival, and mortality of pancreatic cancer. We also provide overviews on the opportunities and challenges associated with vitamin D as an economic adjunct to improve the efficacy of immunotherapy and chemo- or radiotherapy for pancreatic cancer.

Abstract

Pancreatic cancer has a dismal prognosis, while its incidence is increasing. This is attributed, in part, to a profound desmoplastic and immunosuppressive tumor microenvironment associated with this cancer and resistance to current available therapies. Novel and effective intervention strategies are urgently needed to improve the outcomes of patients with pancreatic cancer. Vitamin D has pleiotropic functions beyond calcium–phosphate homeostasis and has been extensively studied both in the laboratory and clinic as a potential preventive agent or adjunct to standard therapies. Accumulating evidence from ecological, observational, and randomized controlled trials suggests that vitamin D has beneficial effects on risk, survival, and mortality in pancreatic cancer, although controversies still exist. Recent advances in demonstrating the important functions of vitamin D/vitamin D receptor (VDR) signaling in the regulation of stromal reprogramming, the microbiome, and immune response and the emergence of checkpoint immunotherapy provide opportunities for using vitamin D or its analogues as an adjunct for pancreatic cancer intervention. Many challenges lie ahead before the benefits of vitamin D can be fully realized in pancreatic cancer. These challenges include the need for randomized controlled trials of vitamin D to assess its impact on the risk and survival of pancreatic cancer, optimizing the timing and dosage of vitamin D or its analogues as an adjunct for pancreatic cancer intervention and elucidating the specific role of vitamin D/VDR signaling in the different stages of pancreatic cancer. Nevertheless, vitamin D holds great promise for reducing risk and improving outcomes of this disease.

TP53 Abnormalities and MMR Preservation in 5 Cases of Proliferating Trichilemmal Tumours

Proliferating trichilemmal tumours (PTT) are defined by a benign squamous cell proliferation inside a trichilemmal cystic (TC) cavity. A possible explanation of this proliferative phenomenon within the cyst may be molecular alterations in genes associated to cell proliferation, which can be induced by ultraviolet radiation. Among other genes, alterations on TP53 and DNA mismatch repair proteins (MMR) may be involved in the cellular proliferation observed in PTT. Based on this assumption, but also taking into account the close relationship between the sebaceous ducts and the external root sheath where TC develop, a MMR, a p53 expression assessment and a TP53 study were performed in a series of 5 PTT cases, including a giant one. We failed to demonstrate a MMR disorder on studied PTT, but we agree with previous results suggesting increased p53 expression in these tumours, particularly in proliferative areas. TP53 alteration was confirmed with FISH technique, demonstrating TP53 deletion in most cells.

Lessons Learned from Paleolithic Models and Evolution for Human Health: A Snap Shot on Beneficial Effects and Risks of Solar Radiation

How to deal with the powerful rays of the sun represents a fundamental question of environmental medicine, affecting skin cancer prevention campaigns and many other aspects of public health. However, when preparing recommendations for sunlight exposure, physicians, scientists, and other health authorities are in a dilemma, because solar radiation exerts both positive and negative effects on human health. While positive effects are at least in part mediated via the UV(Ultraviolet)-B-induced cutaneous synthesis of vitamin D, negative effects include the UV-mediated photocarcinogenesis of skin cancer. During the last century, interest in the positive effects of the sun on our health increased dramatically after the introduction of the so-called vitamin D/cancer hypothesis. In the late 1930s, Peller and Stephenson reported higher rates of skin cancer but lower rates of other cancers among the US Navy personnel. Several years later, Apperly reported an association between latitude and cancer mortality rate in North America. He argued that the "relative immunity to cancer is a direct effect of sunlight". Although the hypothesis that sun exposure may be beneficial against cancer had been proposed early, these observations supporting the hypothesis were ignored for nearly 40 years, until a clear mechanism was proposed. In the 1980s, Garland and Garland published a pilot study focusing on colon cancer and suggested that the possible benefits of sun exposure could be attributed to vitamin D. Later, the proposed protective role of vitamin D was extended to many other types of cancer. Subsequent laboratory investigations supported potential anti-carcinogenic effects of vitamin D compounds. We know today that many, but not all, of the positive effects of the sun on human health are mediated by the UV-induced cutaneous synthesis of vitamin D and other photoproducts. However, because of the abovementioned dilemma, there is an ongoing controversial discussion in scientific communities and in the general population that how much sunlight is optimal for human health. This chapter summarizes the content of the third edition of "Sunlight, Vitamin D and Skin Cancer," a book specifically designed and organized to be an up-to-date review covering the most important aspects of the ongoing debate on how much sun is good for human health and how to balance between the positive and negative effects of solar and artificial UV-radiation, including lessons learned from Paleolithic models and evolution .