Basal cell carcinoma (BCC) is the most common cancer worldwide, and its current treatment options are insufficient and toxic. Surprisingly, unlike several other malignancies, chemopreventive efforts against BCC are almost lacking. Silibinin, a natural agent from milk thistle seeds, has shown strong efficacy against several cancers including ultraviolet radiation-induced skin (squamous) cancer; however, its potential activity against BCC is not yet examined. Herein, for the first time, we report the efficacy of silibinin and its oxidation product 2,3-dehydrosilibinin (DHS) against BCC both in vitro and in vivo using ASZ (p53 mutated) and BSZ (p53 deleted) cell lines derived from murine BCC tumors. Both silibinin and DHS significantly inhibited cell growth and clonogenicity while inducing apoptosis in a dose- and time-dependent manner, with DHS showing higher activity at lower concentrations. Both agents also inhibited the mitogenic signaling by reducing EGFR, ERK1/2, Akt, and STAT3 phosphorylation and suppressed the activation of transcription factors NF-κB and AP-1. More importantly, in an ectopic allograft model, oral administration of silibinin and DHS (200 mg/kg body weight) strongly inhibited the ASZ tumor growth by 44% and 71% (P < 0.05), respectively, and decreased the expression of proliferation biomarkers (PCNA and cyclin D1) as well as NF-κB p50 and c-Fos in the tumor tissues. Taken together, these results provide the first evidence for the efficacy and usefulness of silibinin and its derivative DHS against BCC, and suggest the need for additional studies with these agents in pre-clinical and clinical BCC chemoprevention and therapy models.

Department of Pharmaceutical Sciences Skaggs School of Pharmacy and Pharmaceutical Sciences University of Colorado Denver Aurora Colorado

Institute of Microbiology Laboratory of Biotransformation Academy of Sciences of the Czech Republic Vídeňská Prague Czech Republic

University of Colorado Cancer Center University of Colorado Denver Aurora Colorado

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Wu S, Han J, Li WQ, Li T, Qureshi AA. Basal-cell carcinoma incidence and associated risk factors in U.S. women and men. Am J Epidemiol. 2013;178(6):890–897. PubMed PMC

Athar M, Tang X, Lee JL, Kopelovich L, Kim AL. Hedgehog signalling in skin development and cancer. Exp Dermatol. 2006;15(9):667–677. PubMed

Epstein EH. Basal cell carcinomas: attack of the hedgehog. Nature reviews Cancer. 2008;8(10):743–754. PubMed PMC

Mimeault M, Batra SK. Frequent deregulations in the hedgehog signaling network and cross-talks with the epidermal growth factor receptor pathway involved in cancer progression and targeted therapies. Pharmacol Rev. 2010;62(3):497–524. PubMed PMC

Tang JY, Aszterbaum M, Athar M, et al. Basal cell carcinoma chemoprevention with nonsteroidal anti-inflammatory drugs in genetically predisposed PTCH1+/− humans and mice. Cancer Prev Res (Phila) 2010;3(1):25–34. PubMed PMC

So PL, Lee K, Hebert J, et al. Topical tazarotene chemoprevention reduces Basal cell carcinoma number and size in Ptch1+/− mice exposed to ultraviolet or ionizing radiation. Cancer Res. 2004;64(13):4385–4389. PubMed

Weinstock MA, Bingham SF, Digiovanna JJ, et al. Tretinoin and the prevention of keratinocyte carcinoma (Basal and squamous cell carcinoma of the skin): a veterans affairs randomized chemoprevention trial. J Invest Dermatol. 2012;132(6):1583–1590. PubMed

Zhang B, Liang X, Ye L, Wang Y. No chemopreventive effect of nonsteroidal anti-inflammatory drugs on nonmelanoma skin cancer: evidence from meta-analysis. PLoS One. 2014;9(5):e96887. PubMed PMC

Kasper M, Jaks V, Hohl D, Toftgard R. Basal cell carcinoma - molecular biology and potential new therapies. J Clin Invest. 2012;122(2):455–463. PubMed PMC

Eberl M, Klingler S, Mangelberger D, et al. Hedgehog-EGFR cooperation response genes determine the oncogenic phenotype of basal cell carcinoma and tumour-initiating pancreatic cancer cells. EMBO Mol Med. 2012;4(3):218–233. PubMed PMC

Schnidar H, Eberl M, Klingler S, et al. Epidermal growth factor receptor signaling synergizes with Hedgehog/GLI in oncogenic transformation via activation of the MEK/ERK/JUN pathway. Cancer Res. 2009;69(4):1284–1292. PubMed PMC

Gu D, Fan Q, Zhang X, Xie J. A role for transcription factor STAT3 signaling in oncogene smoothened-driven carcinogenesis. J Biol Chem. 2012;287(45):38356–38366. PubMed PMC

Bickers DR, Athar M. Novel approaches to chemoprevention of skin cancer. The Journal of dermatology. 2000;27(11):691–695. PubMed

Singh RP, Agarwal R. Mechanisms and preclinical efficacy of silibinin in preventing skin cancer. Eur J Cancer. 2005;41(13):1969–1979. PubMed

Dhanalakshmi S, Mallikarjuna GU, Singh RP, Agarwal R. Silibinin prevents ultraviolet radiation-caused skin damages in SKH-1 hairless mice via a decrease in thymine dimer positive cells and an up-regulation of p53-p21/Cip1 in epidermis. Carcinogenesis. 2004;25(8):1459–1465. PubMed

Kaur M, Velmurugan B, Tyagi A, Agarwal C, Singh RP, Agarwal R. Silibinin suppresses growth of human colorectal carcinoma SW480 cells in culture and xenograft through down-regulation of beta-catenin-dependent signaling. Neoplasia. 2010;12(5):415–424. PubMed PMC

Raina K, Agarwal R. Combinatorial strategies for cancer eradication by silibinin and cytotoxic agents: efficacy and mechanisms. Acta pharmacologica Sinica. 2007;28(9):1466–1475. PubMed

Cheung CW, Gibbons N, Johnson DW, Nicol DL. Silibinin--a promising new treatment for cancer. Anti-cancer agents in medicinal chemistry. 2010;10(3):186–195. PubMed

Ramasamy K, Agarwal R. Multitargeted therapy of cancer by silymarin. Cancer letters. 2008;269(2):352–362. PubMed PMC

Gazak R, Svobodova A, Psotova J, et al. Oxidised derivatives of silybin and their antiradical and antioxidant activity. Bioorganic & medicinal chemistry. 2004;12(21):5677–5687. PubMed

Biedermann D, Vavrikova E, Cvak L, Kren V. Chemistry of silybin. Natural product reports. 2014;31(9):1138–1157. PubMed

Agarwal C, Wadhwa R, Deep G, et al. Anti-cancer efficacy of silybin derivatives -- a structure-activity relationship. PLoS One. 2013;8(3):e60074. PubMed PMC

Gažák R, Trouillas P, Biedermann D, et al. Base-catalyzed oxidation of silybin and isosilybin into 2,3-dehydro derivatives. Tetrahedron Letters. 2013;54(4):315–317.

Raina K, Agarwal C, Agarwal R. Effect of silibinin in human colorectal cancer cells: targeting the activation of NF-kappaB signaling. Molecular carcinogenesis. 2013;52(3):195–206. PubMed PMC

Deep G, Kumar R, Jain AK, Agarwal C, Agarwal R. Silibinin inhibits fibronectin induced motility, invasiveness and survival in human prostate carcinoma PC3 cells via targeting integrin signaling. Mutat Res Fundam Mol Mech Mutagen. 2014;768:35–46. PubMed PMC

Agarwal C, Tyagi A, Kaur M, Agarwal R. Silibinin inhibits constitutive activation of Stat3, and causes caspase activation and apoptotic death of human prostate carcinoma DU145 cells. Carcinogenesis. 2007;28(7):1463–1470. PubMed

Chittezhath M, Deep G, Singh RP, Agarwal C, Agarwal R. Silibinin inhibits cytokine-induced signaling cascades and down-regulates inducible nitric oxide synthase in human lung carcinoma A549 cells. Molecular cancer therapeutics. 2008;7(7):1817–1826. PubMed PMC

Deep G, Raina K, Singh RP, Oberlies NH, Kroll DJ, Agarwal R. Isosilibinin inhibits advanced human prostate cancer growth in athymic nude mice: comparison with silymarin and silibinin. Int J Cancer. 2008;123(12):2750–2758. PubMed

Velmurugan B, Gangar SC, Kaur M, Tyagi A, Deep G, Agarwal R. Silibinin exerts sustained growth suppressive effect against human colon carcinoma SW480 xenograft by targeting multiple signaling molecules. Pharmaceutical research. 2010;27(10):2085–2097. PubMed PMC

Derry MM, Raina K, Balaiya V, et al. Grape seed extract efficacy against azoxymethane-induced colon tumorigenesis in A/J mice: interlinking miRNA with cytokine signaling and inflammation. Cancer prevention research (Philadelphia, Pa) 2013;6(7):625–633. PubMed PMC

Herbst RS. Review of epidermal growth factor receptor biology. Int J Radiat Oncol Biol Phys. 2004;59(2 Suppl):21–26. PubMed

Dormoy V, Danilin S, Lindner V, et al. The sonic hedgehog signaling pathway is reactivated in human renal cell carcinoma and plays orchestral role in tumor growth. Molecular cancer. 2009;8:123. PubMed PMC

Nakashima H, Nakamura M, Yamaguchi H, et al. Nuclear factor-kappaB contributes to hedgehog signaling pathway activation through sonic hedgehog induction in pancreatic cancer. Cancer research. 2006;66(14):7041–7049. PubMed

Oeckinghaus A, Hayden MS, Ghosh S. Crosstalk in NF-kappaB signaling pathways. Nature immunology. 2011;12(8):695–708. PubMed

Chang F, Steelman LS, Lee JT, et al. Signal transduction mediated by the Ras/Raf/MEK/ERK pathway from cytokine receptors to transcription factors: potential targeting for therapeutic intervention. Leukemia. 2003;17(7):1263–1293. PubMed

Fresno Vara JA, Casado E, de Castro J, Cejas P, Belda-Iniesta C, Gonzalez-Baron M. PI3K/Akt signalling pathway and cancer. Cancer treatment reviews. 2004;30(2):193–204. PubMed

Gu M, Dhanalakshmi S, Mohan S, Singh RP, Agarwal R. Silibinin inhibits ultraviolet B radiation-induced mitogenic and survival signaling, and associated biological responses in SKH-1 mouse skin. Carcinogenesis. 2005;26(8):1404–1413. PubMed

Gu M, Dhanalakshmi S, Singh RP, Agarwal R. Dietary feeding of silibinin prevents early biomarkers of UVB radiation-induced carcinogenesis in SKH-1 hairless mouse epidermis. Cancer epidemiology, biomarkers & prevention: a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology. 2005;14(5):1344–1349. PubMed

Gu M, Singh RP, Dhanalakshmi S, Agarwal C, Agarwal R. Silibinin inhibits inflammatory and angiogenic attributes in photocarcinogenesis in SKH-1 hairless mice. Cancer Res. 2007;67(7):3483–3491. PubMed

Bigelow RL, Jen EY, Delehedde M, Chari NS, McDonnell TJ. Sonic hedgehog induces epidermal growth factor dependent matrix infiltration in HaCaT keratinocytes. J Invest Dermatol. 2005;124(2):457–465. PubMed

So PL, Wang GY, Wang K, et al. PI3K-AKT signaling is a downstream effector of retinoid prevention of murine basal cell carcinogenesis. Cancer Prev Res (Phila) 2014;7(4):407–417. PubMed PMC

Tewari-Singh N, Jain AK, Inturi S, Agarwal C, White CW, Agarwal R. Silibinin attenuates sulfur mustard analog-induced skin injury by targeting multiple pathways connecting oxidative stress and inflammation. PLoS ONE. 2012;7(9):e46149. PubMed PMC

Yamamoto Y, Gaynor RB. Therapeutic potential of inhibition of the NF-kappaB pathway in the treatment of inflammation and cancer. J Clin Invest. 2001;107(2):135–142. PubMed PMC

Kavitha CV, Deep G, Gangar SC, Jain AK, Agarwal C, Agarwal R. Silibinin inhibits prostate cancer cells- and RANKL-induced osteoclastogenesis by targeting NFATc1, NF-kappaB, and AP-1 activation in RAW264.7 cells. Mol Carcinog. 2014;53(3):169–180. PubMed PMC

Karin M, Liu Z, Zandi E. AP-1 function and regulation. Curr Opin Cell Biol. 1997;9(2):240–246. PubMed

Eferl R, Wagner EF. AP-1: a double-edged sword in tumorigenesis. Nat Rev Cancer. 2003;3(11):859–868. PubMed

Urabe A, Nakayama J, Taniguchi S, Kuroki R, Hori Y. Expression of the fos oncogene in basal cell carcinoma. J Dermatol Sci. 1994;8(1):50–53. PubMed

Bonifas JM, Pennypacker S, Chuang PT, et al. Activation of expression of hedgehog target genes in basal cell carcinomas. J Invest Dermatol. 2001;116(5):739–742. PubMed

Rubin AI, Chen EH, Ratner D. Basal-Cell Carcinoma. New England Journal of Medicine. 2005;353(21):2262–2269. PubMed

Hetal TB, Patel, Sneha, Thakkar A review on techniques for oral bioavailability enhancement of drugs. International Journal of Pharmaceutical Sciences Review & Resear. 2010;4(3):203–223.

Toxicology and carcinogenesis studies of milk thistle extract (CAS No. 84604-20-6) in F344/N rats and B6C3F1 mice (Feed Studies) National Toxicology Program technical report series. 2011;(565):1–177. PubMed

Abenavoli L, Capasso R, Milic N, Capasso F. Milk thistle in liver diseases: past, present, future. Phytotherapy research: PTR. 2010;24(10):1423–1432. PubMed

Flavonolignans silybin, silychristin and 2,3-dehydrosilybin showed differential cytoprotective, antioxidant and anti-apoptotic effects on splenocytes from Balb/c mice

Silymarin Dehydroflavonolignans Chelate Zinc and Partially Inhibit Alcohol Dehydrogenase

Dehydroflavonolignans from Silymarin Potentiate Transition Metal Toxicity In Vitro but Are Protective for Isolated Erythrocytes Ex Vivo

Simple and Rapid HPLC Separation and Quantification of Flavonoid, Flavonolignans, and 2,3-Dehydroflavonolignans in Silymarin

Modulation of Skin Inflammatory Response by Active Components of Silymarin