Yang Qifu, Miyagawa Miku, Liu Xiaoyang, Zhu Beiwei, Munemasa Shintaro, Nakamura Toshiyuki, Murata Yoshiyuki, Nakamura Yoshimasa
a Graduate School of Environmental and Life Science , Okayama University , Okayama , Japan.
b School of Food Science and Technology , Dalian Polytechnic University , Dalian , China.
Biosci Biotechnol Biochem. 2018 Dec;82(12):2158-2167. doi: 10.1080/09168451.2018.1514249. Epub 2018 Sep 10.
Methyl-β-cyclodextrin (MβCD) is an effective agent for the removal of plasma membrane cholesterol. In this study, we investigated the modulating effects of MβCD on the antiproliferation induced by benzyl isothiocyanate (BITC), an ITC compound mainly derived from papaya seeds. We confirmed that MβCD dose-dependently increased the cholesterol level in the medium, possibly through its removal from the plasma membrane of human colorectal cancer cells. The pretreatment with a non-toxic concentration (2.5 mM) of MβCD significantly enhanced the BITC-induced cytotoxicity and apoptosis induction, which was counteracted by the cholesterol supplementation. Although BITC activated the phosphoinositide 3-kinase (PI3K)/Akt pathway, MβCD dose-dependently inhibited the phosphorylation level of Akt. On the contrary, the treatment of MβCD enhanced the phosphorylation of mitogen activated protein kinases, but did not potentiate their BITC-induced phosphorylation. These results suggested that MβCD might potentiate the BITC-induced anti-cancer by cholesterol depletion and thus inhibition of the PI3K/Akt-dependent survival pathway. Abbreviations: CDs: cyclodextrins; MβCD: methyl-β-cyclodextrin; ITCs: isothiocyanates; BITC: benzyl isothiocyanate; PI3K: phosphoinositide 3-kinase; PDK1: phosphoinositide-dependent kinase-1; MAPK: mitogen activated protein kinase; ERK1/2: extracellular signal-regulated kinase1/2; JNK: c-Jun N-terminal kinase; PI: propidium iodide; FBS: fatal bovine serum; TLC: thin-layer chromatography; PBS(-): phosphate-buffered saline without calcium and magnesium; MEK: MAPK/ERK kinase; PIP2: phosphatidylinositol-4,5-bisphosphate; PIP3: phosphatidylinositol-3,4,5-trisphosphate.
甲基-β-环糊精（MβCD）是一种去除质膜胆固醇的有效试剂。在本研究中，我们研究了MβCD对异硫氰酸苄酯（BITC）诱导的抗增殖作用的调节效应，BITC是一种主要来源于木瓜籽的异硫氰酸酯化合物。我们证实，MβCD可能通过从人结肠癌细胞的质膜中去除胆固醇，从而剂量依赖性地增加培养基中的胆固醇水平。用无毒浓度（2.5 mM）的MβCD预处理可显著增强BITC诱导的细胞毒性和凋亡诱导作用，而胆固醇补充可抵消这种作用。尽管BITC激活了磷酸肌醇3激酶（PI3K）/Akt途径，但MβCD剂量依赖性地抑制了Akt的磷酸化水平。相反，MβCD处理增强了丝裂原活化蛋白激酶的磷酸化，但并未增强其BITC诱导的磷酸化。这些结果表明，MβCD可能通过胆固醇耗竭从而抑制PI3K/Akt依赖的生存途径来增强BITC诱导的抗癌作用。缩写：CDs：环糊精；MβCD：甲基-β-环糊精；ITCs：异硫氰酸酯；BITC：异硫氰酸苄酯；PI3K：磷酸肌醇3激酶；PDK1：磷酸肌醇依赖性激酶-1；MAPK：丝裂原活化蛋白激酶；ERK1/2：细胞外信号调节激酶1/2；JNK：c-Jun氨基末端激酶；PI：碘化丙啶；FBS：胎牛血清；TLC：薄层色谱法；PBS(-)：不含钙和镁的磷酸盐缓冲盐水；MEK：MAPK/ERK激酶；PIP2：磷脂酰肌醇-4,5-二磷酸；PIP3：磷脂酰肌醇-3,4,5-三磷酸。
