title: The effectiveness of an anti-human IL-6 receptor monoclonal antibody combined with chemotherapy to target colon cancer stem-like cells.
abstract: Recent studies have demonstrated that cancer stem cells (CSCs) can initiate and sustain tumor growth and exhibit resistance to clinical cytotoxic therapies. Therefore, CSCs represent the main target of anticancer therapy. Interleukin-6 (IL-6) promotes cellular proliferation and drug resistance in colorectal cancer, and its serum levels correlate with patient survival. Therefore, IL-6 and its downstream signaling molecule the signal transducer and activator of transcription-3 (STAT3) represent potential molecular targets. In the present study, we investigated the effects of IL-6 and its downstream signaling components on stem cell biology, particularly the chemoresistance of CSCs, to explore potential molecular targets for cancer therapy. The colon cancer cell line WiDr was cultured in serum-free, non-adherent, and three-dimensional spheroid-forming conditions to enrich the stem cell-like population. Spheroid-forming cells slowly proliferated and expressed high levels of Oct-4, Klf4, Bmi-1, Lgr5, IL-6, and Notch 3 compared with adherent cells. Treatment with an anti-human IL-6 receptor monoclonal antibody reduced spheroid formation, stem cell-related gene expression, and 5-fluorouracil (5-FU) resistance. In addition, IL-6 treatment enhanced the levels of p-STAT3 (Tyr705), the expression of Oct-4, Klf4, Lgr5, and Notch 3, and chemoresistance to 5-FU. siRNA targeting Notch 3 suppressed spheroid formation, Oct-4 and Lgr5 expression, and 5-FU chemoresistance, whereas STAT3 inhibition enhanced Oct-4, Klf4, Lgr5, and Notch 3 expression and 5-FU chemoresistance along with reduced spheroid growth. Taken together, these results indicate that IL-6 functions in dichotomous pathways involving Notch 3 induction and STAT3 activation. The former pathway is involved in cancer stem-like cell biology and enhanced chemoresistance, and the latter pathway leads to accelerated proliferation and reduced chemoresistance. Thus, an anti-human IL-6 receptor monoclonal antibody or Notch 3 inhibition may be superior to STAT3 inhibition for CSC-targeting therapies concomitant with anticancer drugs.
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Jin
authors.initials: J
authors.lastname: Ying
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tsujii
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Jumpei
authors.initials: J
authors.lastname: Kondo
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Motohiko
authors.initials: M
authors.lastname: Kato
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Akasaka
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Takuta
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Shiraishi
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Tahahiro
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hiyama
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Tsujii
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Maekawa
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Kawai
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Fujinaga
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Maekawa
authors.initials: M
authors.lastname: Araki
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Shinzaki
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Watabe
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nishida
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Iijima
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Takehara
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000494:pharmacology*; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D005472:Fluorouracil / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D000090062:Kruppel-Like Factor 4; D014411:Neoplastic Stem Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D000071656:Receptor, Notch3; D019947:Receptors, Interleukin-6 / Q000037:antagonists & inhibitors / Q000235:genetics; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000964:Antimetabolites, Antineoplastic; C508600:IL6 protein, human; D015850:Interleukin-6; C000715467:KLF4 protein, human; D000090062:Kruppel-Like Factor 4; C499374:NOTCH3 protein, human; D000071656:Receptor, Notch3; D019947:Receptors, Interleukin-6; D051880:Receptors, Notch; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; C502936:tocilizumab; D005472:Fluorouracil