Nutritional Science Research Group, Division of Cancer Prevention, National Cancer Institute, Bethesda, MD 20892, USA.
J Nutr Biochem. 2012 Jul;23(7):691-8. doi: 10.1016/j.jnutbio.2012.03.002.
Cancer stem cells often have phenotypic and functional characteristics similar to normal stem cells including the properties of self-renewal and differentiation. Recent findings suggest that uncontrolled self-renewal may explain cancer relapses and may represent a critical target for cancer prevention. It is conceivable that the loss of regulatory molecules resulting from inappropriate consumption of specific foods and their constituents may foster the aberrant self-renewal of cancer stem cells. In fact, increasing evidence points to the network delivering signals for self-renewal from extracellular compartments to the nucleus including changes in stem cell environments, inducible expression of microRNAs, hyperplastic nuclear chromatin structures, and the on/off of differentiation process as possible sites of action for bioactive food components. Diverse dietary constituents such as vitamins A and D, genistein, (-)-epigallocatechin-3-gallate (EGCG), sulforaphane, curcumin, piperine, theanine and choline have been shown to modify self-renewal properties of cancer stem cells. The ability of these bioactive food components to influence the balance between proliferative and quiescent cells by regulating critical feedback molecules in the network including dickkopf 1 (DKK-1), secreted frizzled-related protein 2 (sFRP2), B cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) and cyclin-dependent kinase 6 (CDK6) may account for their biological response. Overall, the response to food components does not appear to be tissue or organ specific, suggesting there may be common cellular mechanisms. Unquestionably, additional studies are needed to clarify the physiological role of these dietary components in preventing the resistance of tumor cells to traditional drugs and cancer recurrence.
癌症干细胞通常具有与正常干细胞相似的表型和功能特征，包括自我更新和分化的特性。最近的发现表明，不受控制的自我更新可能解释癌症的复发，并可能成为癌症预防的一个关键靶点。可以想象，由于不恰当地消耗特定的食物及其成分而导致调节分子的丧失，可能会促进癌症干细胞的异常自我更新。事实上，越来越多的证据表明，从细胞外隔室向核内传递自我更新信号的网络包括干细胞环境的变化、诱导性表达 microRNA、核染色质结构的增生、分化过程的开启和关闭等，都可能是生物活性食物成分的作用部位。多种膳食成分，如维生素 A 和 D、染料木黄酮、(-)-表没食子儿茶素-3-没食子酸酯 (EGCG)、萝卜硫素、姜黄素、胡椒碱、茶氨酸和胆碱，已被证明可以改变癌症干细胞的自我更新特性。这些生物活性食物成分通过调节网络中的关键反馈分子，如 dickkopf 1 (DKK-1)、分泌卷曲相关蛋白 2 (sFRP2)、B 细胞特异性 Moloney 鼠白血病病毒整合位点 1 (Bmi-1) 和周期蛋白依赖性激酶 6 (CDK6)，从而影响增殖细胞和静止细胞之间的平衡，这可能是它们产生生物学反应的原因。总的来说，这些食物成分的反应似乎不是组织或器官特异性的，这表明可能存在共同的细胞机制。毫无疑问，需要进一步的研究来阐明这些膳食成分在预防肿瘤细胞对传统药物的耐药性和癌症复发方面的生理作用。
