Cancer Research, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695014, India.
Cancer Research, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695014, India; Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
Exp Cell Res. 2019 Oct 15;383(2):111551. doi: 10.1016/j.yexcr.2019.111551. Epub 2019 Aug 8.
Cancer stem cells (CSCs) are a subset of cancer cells, which possess self-renewal ability, and lead to tumor progression, metastasis, and resistance to therapy. Live detection and isolation of CSCs are important to understand the biology of CSCs as well as to screen drugs that target them. Even though CSCs are detected using surface markers, there is a lot of inconsistencies for that in a given cancer type. At the same time, self-renewal markers like ALDH1A1, OCT4A and SOX2, which are intracellular molecules, are reliable markers for CSCs in different cancers. In the present study, we generated a reporter construct for self-renewing CSCs, based on ALDH1A1 expression. Oral cancer cells harboring ALDH1A1-DsRed2 were used to screen inhibitors that target CSCs. Our results showed that Comb1, a cocktail of inhibitors for EGF and TGF-β pathways and their intermediates, effectively reduced the DsRed2 population to 34%. Our immunohistochemical analysis on primary oral cancer corroborated the importance of EGF and TGF-β pathways in sustaining CSCs. Since these two pathways are also critical for the self-renewal and differentiation of normal stem cells, Comb1 might abolish them as well. On analysis of the effect of Comb1 on normal murine bone marrow cells, there was no significant change in the stem cell self-renewal and differentiation potential in the treated group compared to untreated cells. To conclude, we claim that ALDH1A1-DsRed2 is a useful tool to detect CSCs, and Comb1 is effective in targeting CSCs without affecting normal stem cells.
癌症干细胞（CSCs）是肿瘤细胞的一个子集，具有自我更新能力，导致肿瘤的进展、转移和对治疗的耐药性。CSCs 的活检测定和分离对于理解 CSCs 的生物学以及筛选针对它们的药物非常重要。尽管 CSCs 是使用表面标志物来检测的，但在给定的癌症类型中，存在很多不一致之处。同时，ALDH1A1、OCT4A 和 SOX2 等细胞内分子的自我更新标志物是不同癌症中 CSCs 的可靠标志物。在本研究中，我们基于 ALDH1A1 的表达生成了一个用于自我更新 CSCs 的报告基因构建体。携带 ALDH1A1-DsRed2 的口腔癌细胞被用于筛选针对 CSCs 的抑制剂。我们的结果表明，针对 EGF 和 TGF-β 途径及其中间产物的抑制剂鸡尾酒 Comb1 可有效将 DsRed2 群体减少到 34%。我们对原发性口腔癌的免疫组织化学分析证实了 EGF 和 TGF-β 途径在维持 CSCs 中的重要性。由于这两个途径对于正常干细胞的自我更新和分化也至关重要，因此 Comb1 可能也会消除它们。在分析 Comb1 对正常小鼠骨髓细胞的影响时，与未处理的细胞相比，处理组中干细胞的自我更新和分化潜力没有明显变化。总之，我们声称 ALDH1A1-DsRed2 是一种用于检测 CSCs 的有用工具，而 Comb1 可有效靶向 CSCs，而不会影响正常干细胞。
