Clinical Utility of 1,25-Dihydroxyvitamin D3 and Its Analogues for the Treatment of Psoriasis
Abstract
The skin is responsible for the sun-induced production of vitamin D. Keratinocytes not only produce vitamin D but are also a target tissue for its active form 1,25-dihydroxyvitamin D3 [1,25(OH)2D]. This is due to the fact that keratinocytes have a vitamin D receptor and when incubated with [1,25(OH)2D] the cells stopped proliferating and began to mature. The potent antiproliferative activity of [1,25(OH)2D] has been used to develop it and its analogues as a novel treatment for psoriasis. Other skin disorders including scleroderma, vitiligo, and ichthyosis have been successfully treated with active vitamin D analogues. This chapter will review the rationale for the use of active vitamin D analogues from various skin disorders and clinical trials, demonstrating efficacy especially for psoriasis.
Key Words
Psoriasis vitamin D analogues 1,25-dihydroxyvitamin D skin diseases 25-hydroxyvitamin D PASI score calcitriol HIV sclerodermaReferences
- 1.Holick MF, MacLaughlin JA, Clark MB, Holick SA, Potts JT, Anderson RR, Blank IH, Parrish JA, Elias P (1980) Photosynthesis of previtamin D3 in human skin and the physiological consequences. Science 210:203–205PubMedCrossRefGoogle Scholar
- 2.Holick MF, MacLaughlin JA, Anderson RR, Parrish J (1982) Photochemistry and photobiology of vitamin D. In: Regan JD, Parrish JA (eds) Photomedicine. Plenum Press, New York, 195–218Google Scholar
- 3.Holick MF, Smith E, Pincus S (1987) Skin as the site of vitamin D synthesis and target tissue for 1,25-dihydroxyvitamin D3. Arch Dermatol 123:1677–1682PubMedCrossRefGoogle Scholar
- 4.Holick MF (1991) Photobiology, physiology and clinical applications for Vitamin D. In: Goldsmith LA (ed) Physiology, biochemistry and molecular biology of the skin, 2nd edn. Oxford University Press, New York, 928–956Google Scholar
- 5.Bittiner B, Bleehen SS, Mac Neil S (1991) 1α-25-(OH)2Vitamin D3 increases intracellular calcium in human keratinocytes. Br J Dermatol 124:12230–12235CrossRefGoogle Scholar
- 6.MacLaughlin JA, Cantley LC, Holick MF (1990) 1,25(OH)2D3 increases calcium and phosphatidylinositol metabolism in differentiating cultured human keratinocytes. J Nutr Biochem 1:81–87PubMedCrossRefGoogle Scholar
- 7.Haussler MR (1986) Vitamin D receptors: nature and function. Annu Rev Nutr 6:527–562PubMedCrossRefGoogle Scholar
- 8.Haussler MR, Mangelsdorf DJ, Komm BS, Terpening CM, Yamaoka K, Allegretto EA, Baker AR, Shine J, McDonnell DP, Hughes M, Weigel NL, O’Malley BW (1988) Molecular biology of the vitamin D hormone. Recent Prog Horm Res 44:263–305PubMedGoogle Scholar
- 9.Baker AR, Mc Donnell DP, Hughes M, Crisp TM, Mangelsdorf DJ, Haussler MR, Pike JW, Shine J, O’Malley BW (1988) Cloning and expression of full-length cDNA encoding human vitamin D receptor. Proc Natl Acad Sci USA 85:3294–3298PubMedCrossRefGoogle Scholar
- 10.Yu VC, Deisert C, Andersen B, Holloway JM, Devary OV, Näär AM, Kim SY Boutin JM, Glass CK, Rosenfeld MG (1991) RXRβ: a coregulator that enhances binding of retinoic acid, thyroid hormone and vitamin D receptors to their cognate response elements. Cell 67:1251–1266PubMedCrossRefGoogle Scholar
- 11.Leid M, Kastner P, Lyons R, Nakshatri H, Saunders M, Zacharewski T, Chen J, Staub A, Garnier J, Mader S, Chambon P (1992) Purification, cloning, and RXR identity of the HeLa cell factor with which RAR or TR heterodimerizes to bind target sequences efficiently. Cell 68:377–395PubMedCrossRefGoogle Scholar
- 12.Milde P, Hauser U, Simon R, Mall G, Ernst V, Haussler MR, Frosch P, Rauterberg EW (1991) Expression of 1,25-dihydroxyvitamin D3 receptors in normal and psoriatic skin. J Invest Dermatol 97:230–239PubMedCrossRefGoogle Scholar
- 13.Reichrath J, Münssinger T, Kerber A, Rochette-Egly C, Chambon P, Bahmer FA, Baum HP (1995). In situ detection of retinoid-X receptor expression in normal and psoriatic human skin. Br J Dermatol 133:168–175PubMedCrossRefGoogle Scholar
- 14.Smith EL, Walworth NC, Holick MF (1986) Effect of 1α-25-dihydroxyvitamin D3 on the morphologic and biochemical differentiation of cultured human epidermal keratinocytes grown under serum-free conditions. J Invest Dermatol 86:709–714PubMedCrossRefGoogle Scholar
- 15.Hosomi J, Hosoi J, Abe E, Suda T, Kuroki T (1983) Regulation of terminal differentiation of cultured mouse epidermal cells by 1-alpha 25-dihydroxy-vitamin D3. Endocrinol 113:1950–1957CrossRefGoogle Scholar
- 16.Gniadecki R, Serup J (1995) Stimulation of epidermal proliferation in mice with 1 alpha, 25-dihydroxyvitamin D3 and receptor-active 20-EPI analogues of 1 alpha, 25-dihydroxyvitamin D3. Biochem Pharmacol 49:621–624PubMedCrossRefGoogle Scholar
- 17.Rigby WFC (1988) The immunobiology of vitamin D. Immunol Today 9:54–58PubMedCrossRefGoogle Scholar
- 18.Texereau M, Viac J, Vitamin D (1992) immune system and skin. Europ J Dermatol 2:258–264Google Scholar
- 19.Ranson M, Posen S, Mason RS (1988) Human melanocytes as a target tissue for hormones: in vitro studies with 1α,25-dihydroxyvitamin D3, alpha-melanocyte stimulating hormone, and beta-estradiol. J Invest Dermatol 91:593–598PubMedCrossRefGoogle Scholar
- 20.Christophers E, Henseler T (1985) Psoriasis of early and late onset: characterization of two types of psoriasis vulgaris. J Am Acad Dermatol 13:450–456PubMedCrossRefGoogle Scholar
- 21.Christophers E, Henseler T (1989) Patient subgroups and the inflammatory pattern in psoriasis. Acta Derm Venereol (Stockh) 69:88–92Google Scholar
- 22.Elder JT, Henseler T, Christophers E, Voorhees JJ, Nair RP (1994) Of genes and antigens: the inheritance of psoriasis. J Invest Dermatol 103:150S–153SPubMedCrossRefGoogle Scholar
- 23.Valdimarsson H, Baker BS, Jonsdittir I, Fry L (1986) Psoriasis: a disease of abnormal keratinocyte proliferation induced by T lymphocytes. Immunol Today 7:256–259CrossRefGoogle Scholar
- 24.Lee RE, Gaspari AA, Lotze MT, Chang AE, Rosenberg SA (1988) Interleukin 2 and psoriasis. Arch Dermatol 124:1811–1815PubMedCrossRefGoogle Scholar
- 25.Barker JN, Jones ML, Mitra RS, Crockett Torab E, Fantone JC, Kunkel SL, Warren JS, Dixit VM, Nickoloff BJ (1991) Modulation of keratinocyte derived interleukin-8 which is chemotactic for neutrophils and T lymphocytes. Am J Pathol 139:869–876PubMedGoogle Scholar
- 26.Gottlieb AB (1990) Immunologic mechanisms in psoriasis. J Invest Dermatol 95:18S–19SCrossRefGoogle Scholar
- 27.Schlaak JF, Buslau M, Jochum W, Hermann E, Girndt M, Gallati H, Meyer zum Büschenfelde KH, Fleischer B (1994). T cells involved in psoriasis vulgaris belong to the Th1 subset. J Invest Dermatol 102:145–149PubMedCrossRefGoogle Scholar
- 28.van Reijsen FC, Druijnzeel-Koomen CAFM, Kalthoff FS, Maggi E, Romagnani S, Westland JKT, Mudde GC (1992) Skin-derived aeroallergen-specific T-cell clones of Th2 phenotype in patients with atopic dermatitis. J Allergy Clin Immunol 90:184–192PubMedCrossRefGoogle Scholar
- 29.Leung DY, Walsh P, Giorno R, Norris DA (1993) A potential role for superantigens in the pathogenesis of psoriasis. J Invest Dermatol 100:225–228PubMedCrossRefGoogle Scholar
- 30.Zenz R, Eferl R, Kenner L, Florin L, Hummerich L, Mehic D, Scheuch H, Angel P, Tschachler E, Wagner EF (2005) Psoriasis-like skin disease and arthritis caused by inducible epidermal deletion of Jun proteins. Nature 437(7057):369–375PubMedCrossRefGoogle Scholar
- 31.Chowaniec O, Jablonska S, Beutner EH, Proniewska M, Jarzabek Chorzelska M, Rzesa G (1981) Earliest clinical and histological changes in psoriasis. Dermatologica 163:42–51PubMedCrossRefGoogle Scholar
- 32.MacLaughlin JA, Gange W, Taylor D, Smith E, Holick MF (1985) Cultured psoriatic fibroblasts from involved and uninvolved sites have partial but not absolute resistance to the proliferation-inhibition activity of 1,25-dihydroxyvitamin D3. Proc Natl Acad Sci USA 82:5409–5412PubMedCrossRefGoogle Scholar
- 33.Morimoto S, Kumahara Y (1985) A patient with psoriasis cured by 1α-hydroxyvitamin D3. Med J Osaka Univ 35(3–4):51–54PubMedGoogle Scholar
- 34.Morimoto S, Yochikawa K, Kozuka T, Kitano Y, Imawaka S, Fukuo K, Koh E, Kumahara Y (1986) An open study of vitamin D3 treatment in psoriasis vulgaris. Br J Dermatol 115:421–429PubMedCrossRefGoogle Scholar
- 35.Holick MF, Chen ML, Kong XF, Sanan DK (1996) Clinical uses for calciotropic hormones 1,25-dihydroxyvitamin D3 and parathyroid hormone related peptide in dermatology: a new perspective. J Invest Dermatol (Symp Proc) 1:1–9Google Scholar
- 36.Perez A, Chen TC, Turner A, Raab R, Bhawan J, Poche P, Holick MF (1996) Efficacy and safety of topical calcitriol (1,25-dihydroxyvitamin D3) for the treatment of psoriasis. Br J Dermatol 134:238–246PubMedCrossRefGoogle Scholar
- 37.Kragballe K, Beck HI, Sogaard H (1988) Improvement of psoriasis by topical vitamin D3 analogue (MC 903) in a double-blind study. Br J Dermatol 119:223–230PubMedCrossRefGoogle Scholar
- 38.van de Kerkhof PCM, van Bokhoven M, Zultak M, Czarnetzki BM (1989) A double-blind study of topical 1α-25-dihydroxyvitamin D3 in psoriasis. Br J Dermatol 120:661–664PubMedCrossRefGoogle Scholar
- 39.Helfrich YR, Kang S, Hamilton TA, Voorhees JJ (2007) Topical becocalcidiol for the treatment of psoriasis vulgaris: a randomized, placebo-controlled, double-blind, multicentre study. Br J Dermatol 157(2):369–374PubMedCrossRefGoogle Scholar
- 40.Perez A, Raab R, Chen TC, Turner A, Holick MF (1996) Safety and efficacy of oral calcitriol (1,25-dihydroxyvitamin D3) for the treatment of psoriasis. Br J Dermatol 134:1070–1078PubMedCrossRefGoogle Scholar
- 41.Van de Kerkhof PC, Vissers WH (2003) The topical treatment of psoriasis. Skin Pharmacol Appl Skin Physiol 16:69–83PubMedGoogle Scholar
- 42.Kragballe K, Gjertsen BT, de Hoop D, Karlsmark T, van de Kerhof PCM, Larko O, Nieboer C, Roed-Petersen J, Strand A, Tikjob B (1991) Double-blind right/left comparison of calcipotriol and betamethasone valerate in treatment of psoriasis vulgaris. Lancet 337:193–196PubMedCrossRefGoogle Scholar
- 43.Tzaneva S, Hönigsmann H, Tanew A (2003) Observer-blind, randomized, intrapatient comparison of a novel 1% coal tar preparation (Exorex R) and calcipotriol cream in the treatment of plaque type psoriasis. Br J Dermatol 149:350–353PubMedCrossRefGoogle Scholar
- 44.De Korte J, van der Valk PG, Sprangers MA, Damstra RJ, Kunkeler AC, Lijnen RL, Oranje AP, de Rie MA, de Waard-van der Spek FB, Hol CW, van de Kerkhof PC (2008) A comparison of twice-daily calcipotriol ointment with once-daily short-contact dithranol cream therapy: quality-of-life outcomes of a randomized controlled trial of supervised treatment of psoriasis in a day-care setting. Br J Dermatol 158(2):375–381PubMedCrossRefGoogle Scholar
- 45.Kragballe K, Barnes L, Hamberg KJ, Hutchinson P, Murphy F, Moller S et al (1998) Calcipotriol cream with or without concurrent topical corticosteroid in psoriasis: tolerability and efficacy. Br J Dermatol 139:649–654PubMedCrossRefGoogle Scholar
- 46.Zhu X, Wang B, Zhao G, Gu J, Chen Z, Briantais P, Andres P (2007) An investigator-masked comparison of the efficacy and safety of twice daily applications of calcitriol 3 μg/g ointment vs. calcipotriol 50 μg/g ointment in subjects with mild to moderate chronic plaque-type psoriasis. J Eur Acad Dermatol Venereol 21(4):466–472PubMedGoogle Scholar
- 47.Serup J (1994) Calcipotriol irritation: mechanism, diagnosis and clinical implication. Acta Derm Venereol (Stockh) Abstr 186:42SGoogle Scholar
- 48.Ezquerra GM, Regana MS, Millet PU (2007) Combination of acitretin and oral calcitriol for treatment of plaque-type psoriasis. Acta Derm Venereol 87(5):449–450PubMedCrossRefGoogle Scholar
- 49.Green C, Ganpule M, Harris D, Kavanagh G, Kennedy C, Mallett R, Rustin M, Downes N (1994) Comparative effects of calcipotriol (MC 903) solution and placebo (vehicle of MC 903) in the treatment of psoriasis of the scalp. Br J Dermatol 130:483–487PubMedCrossRefGoogle Scholar
- 50.Petrow W (1995) Treatment of a nail psoriasis with calcipotriol. Akt Dermatol 21:396–400Google Scholar
- 51.Liao YH, Chiu HC, Tseng YS, Tsai TF (2007) Comparison of cutaneous tolerance and efficacy of calcitriol 3 μg/g ointment and tacrolimus 0.3 mg/g ointment in chronic plaque psoriasis involving facial or genitofemoral areas: a double-blind, randomized controlled trial. Br J Dermatol 157(5):1005–1012PubMedCrossRefGoogle Scholar
- 52.Saggese G, Federico G, Battini R (1993) Topical application of 1,25 dihydroxyvitamin D3 (calcitriol) is an effective and reliable therapy to cure skin lesions in psoriatic children. Eur J Pediatr 152:389–392PubMedCrossRefGoogle Scholar
- 53.Perez A, Chen TC, Turner A, Holick MF (1995) Pilot study of topical calcitriol (1,25-dihydroxyvitamin D3) for treating psoriasis in children. Arch Dermatol 131:961–962PubMedCrossRefGoogle Scholar
- 54.Gray JD, Bottomley W, Layton AM, Cotterill JA, Monteiro E (1992) The use of calcipotriol in HIV-related psoriasis. Clin Exp Dermatol 17(5):342–343PubMedCrossRefGoogle Scholar
- 55.Grossman RM, Thivolet J, Claudy A, Souteyrand P, Guilhou JJ, Thomas P, Amblard P, Belaich S, de Belilovsky C, de la Brassinne M et al (1994) A novel therapeutic approach to psoriasis with combination calcipotriol ointment and very low-dose cyclosporine: a result of a multicenter placebo-controlled study. J Am Acad Dermatol 31:68–74PubMedCrossRefGoogle Scholar
- 56.Kerscher M, Volkenandt M, Plewig G, Lehmann P (1993) Combination phototherapy of psoriasis with calcipotriol and narrow band UVB. Lancet 342:923PubMedCrossRefGoogle Scholar
- 57.Cambazard F, van de Kerkhof PCM, Hutchinson PE, and the Calcipotriol Study Group (1996) Proceedings of the 3rd International Calcipotriol Symposium, Munich Germany, 23 March 1996.Google Scholar
- 58.Ortonne JP (1994) Calcipotriol in combination with betamethasone dipropionate. Nouv Dermatol 13:736–751Google Scholar
- 59.Kragballe K (1990) Combination of topical calcipotriol (MC 903) and UVB radiation for psoriasis vulgaris. Dermatologica 181:211–214PubMedCrossRefGoogle Scholar
- 60.Toole JW (2007) Calcipotriol and betamethasone dipropionate for the treatment of psoriasis: a 52-week study. Skin Therapy Lett 12(4):1–3PubMedGoogle Scholar
- 61.Bottomley JM, Auland ME, Morais J, Boyd G, Douglas WS (2007) Cost-effectiveness of the two-compound formulation calcipotriol and betamethasone dipropionate compared with commonly used topical treatments in the management of moderately severe plaque psoriasis in Scotland. Curr Med Res Opin 23(8):1887–1901PubMedCrossRefGoogle Scholar
- 62.Adachi Y, Uchida N, Matsuo T, Horio T (2008) Clinical effect of vitamin D3 analogues is not inactivated by subsequent UV exposure. Photodermatol Photoimmunol Photomed 24(1):16–18PubMedCrossRefGoogle Scholar
- 63.Lucker GP, van de Kerkhof PC, van Dijk MR, Steijlen PM (1994) Effect of topical calcipotriol on congenital ichthyosis. Br J Dermatol 131:546–550PubMedCrossRefGoogle Scholar
- 64.Humbert P, Dupond JL, Agache P, Laurent R, Rochefort A, Drobacheff C, de Wazieres B, Aubin F (1993) Treatment of scleroderma with oral 1,25-dihydroxyvitamin D3: evaluation of skin involvement using non-invasive techniques. Results of an open prospective trial. Acta Derm Venereol (Stockh) 73:449–451Google Scholar
- 65.Kumaran MS, Kaur I, Kumar B (2006) Effect of topical calcipotriol, betamethasone dipropionate and their combination in the treatment of localized vitiligo. J Eur Acad Dermatol Venereol 20(3):269–273PubMedCrossRefGoogle Scholar
- 66.Amano H, Abe M, Ishikawa O (2008) First case report of topical tacalcitol for vitiligo repigmentation. Pediatr Dermatol 25(2):262–264PubMedCrossRefGoogle Scholar
- 67.Goldinger SM, Dummer R, Schmid P, Burg G, Seifert B, Läuchli S (2007) Combination of 308-nm xenon chloride excimer laser and topical calcipotriol in vitiligo. J Eur Acad Dermatol Venereol 21(4):504–508PubMedGoogle Scholar
- 68.Koeffler HP, Hirji K, Itri L (1985) 1,25-dihydroxyvitamin D3: in vivo and in vitro effects on human preleukemic and leukemic cells. Cancer Treat Rep 69:1399–1407PubMedGoogle Scholar
- 69.Colston KW, Chander SK, Mackay AG, Coombes RC (1992) Effects of synthetic vitamin D analogues on breast cancer cell proliferation in vivo and in vitro. Biochem Pharmacol 44:693–702PubMedCrossRefGoogle Scholar
- 70.Franceschi RT, Linson CJ, Peter CT, Romano PR (1987) Regulation of cellular adhesion and fibronectin synthesis by 1α,25-dihydroxyvitamin D3. J Biol Chem 262:4165–4171PubMedGoogle Scholar
- 71.Eisman JA, Barkla DH, Tutton PJM (1987) Suppression of in vivo growth of human cancer solid tumor xenografts by 1α,25-dihydroxyvitamin D3. Cancer Res 47:21–25PubMedGoogle Scholar
- 72.Reichrath J, Müller SM, Kerber A, Baum HP, Bahmer FA (1997) Biological effects of topical calcipotriol (MC 903) treatment in psoriatic skin. J Am Acad Dermatol 36(1):19–28PubMedCrossRefGoogle Scholar
- 73.Chen ML, Perez A, Sanan DK, Heinrich G, Chen TC, Holick MF (1996) Induction of vitamin D receptor mRNA expression in psoriatic plaques correlates with clinical response to 1,25-dihydroxyvitamin D3. J Invest Dermatol 106:637–641PubMedCrossRefGoogle Scholar
- 74.Missero C, Calautti E, Eckner R, Chin J, Tsai LH, Livingston DM, Dotto GP (1995) Involvement of the cell-cycle inhibitor Cip1/WAF1 and the E1A-associated p300 protein in terminal differentiation. Proc Natl Acad Sci USA 92:5451–5455PubMedCrossRefGoogle Scholar
- 75.Ziv E, Rotem C, Miodovnik M, Ravid A, Koren R (2008) Two modes of ERK activation by TNF in keratinocytes: different cellular outcomes and bi-directional modulation by vitamin D. J Cell Biochem 104(2):606–619PubMedCrossRefGoogle Scholar
- 76.Binderup L, Latini S, Binderup E, Bretting C, Calverley M, Hansen K (1991) 20-epi-vitamin D3 analogues: a novel class of potent regulators of cell growth and immune response. Biochem Pharmacol 42:1569–1575PubMedCrossRefGoogle Scholar
- 77.Neef G, Kirsch G, Schwarz K, Wiesinger H, Menrad A, Fähnrich M, Thieroff-Eckerdt R, Steinmeyer A (1994) 20-methyl vitamin D analogues. In: Norman AW, Bouillon R, Thomasset M (eds.) Vitamin D. A pluripotent steroid hormone: structural studies, molecular endocrinology and clinical applications. Walter de Gruyter, Berlin, pp. 97–98Google Scholar
- 78.Schönecker B, Reichenbächer M, Gliesing S, Prousa R, Wittmann S, Breiter S, Thieroff-Eckerdt R, Wiesinger H, Haberey M, Scheddin D, Mayer H (1994) 2β-substituted calcitriols and other A-ring substituted analogues – synthesis and biological results. In: Norman AW, Bouillon R, Thomasset M (eds) Vitamin D. A pluripotent steroid hormone: structural studies, molecular endocrinology and clinical applications. Walter de Gruyter, Berlin, pp. 99–100Google Scholar
- 79.Chen TC, Persons KS, Zheng S, Mathieu J, Holick MF, Lee YF, Bao B, Arai MA, Kittaka A (2007) Evaluation of C-2-substituted 19-nor-1alpha,25-dihydroxyvitamin D3 analogs as therapeutic agents for prostate cancer. J Steroid Biochem Mol Biol 103(3–5):717–720PubMedCrossRefGoogle Scholar
- 80.Schuster I, Herzig G, Vorisek G(1994) Steroidal hormones as modulators of vitamin D metabolism in human keratinocytes. In: Norman AW, Bouillon R, Thomasset M (eds) Vitamin D. A pluripotent steroid hormone: structural studies, molecular endocrinology and clinical applications. Walter de Gruyter, Berlin, pp. 184–185Google Scholar
- 81.Zhao J, Marcelis S, Tan BK, Verstuaf A, Boillon R (1994) Potentialisation of vitamin D (analogues) by cytochrome P-450 enzyme inhibitors is analog- and cell-type specific. In: Norman AW, Bouillon R, Thomasset M (eds) Vitamin D. A pluripotent steroid hormone: structural studies, molecular endocrinology and clinical applications. Walter de Gruyter, Berlin, pp. 97–98Google Scholar
- 82.Segersten U, Björklund P, Hellman P, Akerström G, Westin G (2007) Potentiating effects of nonactive/active vitamin D analogues and ketoconazole in parathyroid cells. Clin Endocrinol (Oxf) 66(3):399–404CrossRefGoogle Scholar
- 83.Carlberg C, Bendik I, Wyss A, Meier E, Sturzenbecker LJ, Grippo JF, Hunziker W (1993) Two nuclear signalling pathways for vitamin D. Nature 361:657–660PubMedCrossRefGoogle Scholar
- 84.Schräder M, Müller KM, Becker-Andre M, Carlberg C (1994) Response element selectivity for heterodimerization of vitamin D receptors with retinoic acid and retinoid X receptors. J Mol Endocrinol 12:327–339PubMedCrossRefGoogle Scholar
- 85.Deeb KK, Trump DL, Johnson CS (2007) Vitamin D signalling pathways in cancer: potential for anticancer therapeutics. Nat Rev Cancer 7(9):684–700PubMedCrossRefGoogle Scholar