Phenylmethimazole decreases Toll-like receptor 3 and noncanonical Wnt5a expression in pancreatic cancer and melanoma together with tumor cell growth and migration.
OBJECTIVE
To evaluate whether (a) Wnt5a expression in pancreatic cancer and malignant melanoma cells might be associated with constitutive levels of Toll-like receptor 3 (TLR3) and/or TLR3 signaling; (b) phenylmethimazole (C10), a novel TLR signaling inhibitor, could decrease constitutive Wnt5a and TLR3 levels together with cell growth and migration; and (c) the efficacy of C10 as a potential inhibitor of pancreatic cancer and malignant melanoma cell growth in vivo.


METHODS
We used a variety of molecular biology techniques including but not limited to PCR, Western blotting, and ELISA to evaluate the presence of constitutively activated TLR3/Wnt5a expression and signaling. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide-based technology and scratch assays were used to evaluate inhibition of cell growth and migration, respectively. TLR3 regulation of cell growth was confirmed using small interfering RNA technology. Nude and severe combined immunodeficient mice were implanted with human pancreatic cancer and/or melanoma cells and the effects of C10 on tumor growth were evaluated.


RESULTS
We show that constitutive TLR3 expression is associated with constitutive Wnt5a in human pancreatic cancer and malignant melanoma cell lines, that C10 can decrease constitutive TLR3/Wnt5a expression and signaling, suggesting that they are interrelated signal systems, and that C10 inhibits growth and migration in both of these cancer cell lines. We also report that C10 is effective at inhibiting human pancreatic cancer and malignant melanoma tumor growth in vivo in nude or severe combined immunodeficient mice and associate this with inhibition of signal transducers and activators of transcription 3 activation.


CONCLUSIONS
C10 may have potential therapeutic applicability in pancreatic cancer and malignant melanoma.
Schwartz
Anthony L
AL
Edison Biotechnology Institute, Diabetes Research Center, College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, USA.
Malgor
Ramiro
R
Dickerson
Eric
E
Weeraratna
Ashani T
AT
Slominski
Andrzej
A
Wortsman
Jacobo
J
Harii
Norikazu
N
Kohn
Aimee D
AD
Moon
Randall T
RT
Schwartz
Frank L
FL
Goetz
Douglas J
DJ
Kohn
Leonard D
LD
McCall
Kelly D
KD
D000818:Animals; D013956:Antithyroid Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D054357:Chemokine CXCL10 / Q000037:antagonists & inhibitors / Q000378:metabolism; D055785:Gene Knockdown Techniques; D006801:Humans; D016899:Interferon-beta / Q000037:antagonists & inhibitors / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008545:Melanoma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D008713:Methimazole / Q000031:analogs & derivatives* / Q000494:pharmacology; D051379:Mice; D008819:Mice, Nude; D016513:Mice, SCID; D010190:Pancreatic Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D012878:Skin Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D013871:Thiones / Q000494:pharmacology*; D051196:Toll-Like Receptor 3 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051153:Wnt Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000071818:Wnt-5a Protein; D000093242:Interleukin-6 Inhibitors
D013956:Antithyroid Agents; D054357:Chemokine CXCL10; D016899:Interferon-beta; D015850:Interleukin-6; D008713:Methimazole; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D050796:STAT3 Transcription Factor; D013871:Thiones; D051196:Toll-Like Receptor 3; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; D000093242:Interleukin-6 Inhibitors; C114753:CXCL10 protein, human; C508600:IL6 protein, human; C494086:STAT3 protein, human; C495344:TLR3 protein, human; C085389:WNT5A protein, human; C489637:phenyl methimazole