Calcipotriol and regression in T-cell lymphoma of skin

Vitamin D in Cutaneous T-Cell Lymphoma

Cutaneous T-cell lymphoma (CTCL) is characterized by the proliferation of malignant T cells in inflamed skin lesions. Mycosis fungoides (MF)-the most common variant of CTCL-often presents with skin lesions around the abdomen and buttocks ("bathing suit" distribution), i.e., in skin areas devoid of sun-induced vitamin D. For decades, sunlight and vitamin D have been connected to CTCL. Thus, vitamin D induces apoptosis and inhibits the expression of cytokines in malignant T cells. Furthermore, CTCL patients often display vitamin D deficiency, whereas phototherapy induces vitamin D and has beneficial effects in CTCL, suggesting that light and vitamin D have beneficial/protective effects in CTCL. Inversely, vitamin D promotes T helper 2 (Th2) cell specific cytokine production, regulatory T cells, tolerogenic dendritic cells, as well as the expression of immune checkpoint molecules, all of which may have disease-promoting effects by stimulating malignant T-cell proliferation and inhibiting anticancer immunity. Studies on vitamin D treatment in CTCL patients showed conflicting results. Some studies found positive effects, others negative effects, while the largest study showed no apparent clinical effect. Taken together, vitamin D may have both pro- and anticancer effects in CTCL. The balance between the opposing effects of vitamin D in CTCL is likely influenced by treatment and may change during the disease course. Therefore, it remains to be discovered whether and how the effect of vitamin D can be tilted toward an anticancer response in CTCL.

Nonpsoriatic Uses of Calcipotriol

Background:

Calcipotriol is a synthetic vitamin D3 analog that binds to vitamin D receptors in epidermal cells. In vitro studies have shown that calcipotriol stimulates terminal cell differentiation and has antiproliferative effects. In vivo, calcipotriol has been shown to reduce the number of cycling epidermal cells. Calcipotriol also has less effect on calcium metabolism than calcitriol, which is the natural, bioactive, 1,25-dihydroxyvitamin D3.

Objective:

These properties make calcipotriol an ideal candidate for the topical treatment of hyperproliferative skin disorders. While it has been approved for topical use in psoriasis, its potential for use in other dermatological disorders has not yet been fully investigated.

Conclusion:

This survey of the literature suggests that calcipotriol may show promise in the treatment of other conditions involving abnormal keratinization and hyperproliferation of epidermal cells. While some of these disorders are rare, and therefore difficult to study, further study into the nonpsoriatic uses of calcipotriol may be rewarding.

Trends in on and off-label calcipotriene use

Following its introduction in 1994, calcipotriene quickly became the single most prescribed medication for psoriasis according to National Ambulatory Medical Care Survey (NAMCS) data. Primarily through regulation of cellular differentiation, calcipotriene may be effective in dermatoses other than psoriasis. We characterize the clinical trends in the utilization of calcipotriene by analyzing a representative sample of visits to US physicians. Demographic characteristics, specialty of the provider, and off-label uses are reported. Calcipotriene was mentioned at 5.8 million of all NAMCS visits during the study period. Nearly 57% of mentions of calcipotriene were not linked to a diagnosis of psoriasis. Adjusted use for gender and race were relatively stable; there was a rise in non-psoriasis uses and use among non-dermatologists in 1997. Our findings support previous reports of the utility of calcipotriene in treating other dermatoses as witnessed by the numerous conditions for which its use was observed. Physicians and policy-makers should be aware of the role that this medication plays in the delivery of dermatologic care.

The therapeutic potential of calcipotriol in diseases other than psoriasis

BACKGROUND

Calcipotriol is a vitamin D analog, which has antiproliferative and anti- inflammatory effects, and stimulates terminal differentiation. It has been an established treatment for psoriasis since 1991 in Europe and 1994 in the USA.

OBJECTIVE

To assess the clinical efficacy of topical calcipotriol in diseases other than psoriasis.

RESULTS

A total of 36 original papers were found describing 21 different diseases in which the clinical use of calcipotriol ointment was described as having an effect. These papers were predominantly case reports (n = 22) and observational studies (n = 5), but nine papers described small randomized controlled trials.

CONCLUSIONS

Calcipotriol may generally be effective in diseases characterized by pathogenic elements, such as impaired differentiation or increased keratinocyte proliferation, and activated T lymphocytes. This study of the existing literature suggests that randomized, double-blind, placebo-controlled studies of calcipotriol therapy may be worthwhile in a number of diseases.

Transitional cell carcinoma express vitamin D receptors

Recently, vitamin D analogues have shown antineoplastic effect in several diseases. Vitamin D analogues exert its effect by interacting with the vitamin D receptor (VDR). Studies of VDR in transitional cell carcinoma (TCC) have not been reported. The purpose of the present study was therefore to examine whether human bladder tumor cells express VDR. Tumor biopsies were obtained from 26 patients with TCC. Expression of VDR was examined by immunohistochemical experiments. All tumors expressed VDR. Biopsies from advanced disease contained more VDR positive cells than low stage disease (p < 0.05). Similarly, also tumor grade appeared to be related to the number of cells expressing the receptor. Normal urothlium also expressed VDR but only with low intensity. Our study shows that TCC cells possess the VDR receptor which may make them capable to respond to stimulation with vitamin D, but functional studies of vitamin D's effect on TCC cells in vitro are necessary before the efficacy of treatment with vitamin D analogues in TCC can be evaluated in patients.

Growth-inhibitory effects of vitamin D analogues and retinoids on human pancreatic cancer cells

Retinoids and vitamin D are important factors that regulate cellular growth and differentiation. An additive growth-inhibitory effect of retinoids and vitamin D analogues has been demonstrated for human myeloma, leukaemic and breast cancer cells. We set out to study the effects of the vitamin D analogue EB1089 and the retinoids all-trans- and 9-cis-retinoic acid on the human pancreatic adenocarcinoma cell lines Capan 1 and Capan 2 and the undifferentiated pancreatic carcinoma cell line Hs766T. The cell lines investigated expressed vitamin D receptor, retinoic acid receptor (RAR)-alpha and gamma as determined by polymerase chain reaction after reverse transcription. RAR-beta was expressed only in Hs766T cells. Addition of all-trans-retinoic acid increased the amount of RAR-alpha mRNA in the three cell lines and induced RAR-beta mRNA in Capan 1 and Capan 2 cells. All-trans-retinoic acid at a concentration of 10 nM inhibited the growth of Capan 1 and Capan 2 cells by 40% relative to controls. 9-cis-Retinoic acid was less effective. Neither all-trans-retinoic acid nor 9-cis-retinoic acid affected the growth of Hs766T cells. EB1089, if added alone to the cells, did not significantly inhibit growth. However, the combination of 1 nM EB1089 with 10 nM all-trans-retinoic acid exerted a growth-inhibitory effect of 90% in Capan 1 cells and of 70% in Capan 2 cells. Our data suggest that vitamin D analogues together with retinoids inhibit the growth of human pancreatic cancer cells. However, in vivo studies are necessary to examine the potential use of retinoids and vitamin D analogues on pancreatic cancer.

Dermatologic therapy: 1993

This article reviews some therapeutic results reported in the English-language literature during 1993. Readers should review the original article in full before attempting any experimental or controversial therapy.