Investigation of discriminant metabolites in tamoxifen-resistant and choline kinase-alpha-downregulated breast cancer cells using 1H-nuclear magnetic resonance spectroscopy

Metabolites linked to changes in choline kinase-α (CK-α) expression and drug resistance, which contribute to survival and autophagy mechanisms, are attractive targets for breast cancer therapies. We previously reported that autophagy played a causative role in driving tamoxifen (TAM) resistance of breast cancer cells (BCCs) and was also promoted by CK-α knockdown, resulting in the survival of TAM-resistant BCCs. There is no comparative study yet about the metabolites resulting from BCCs with TAM-resistance and CK-α knockdown. Therefore, the aim of this study was to explore the discriminant metabolic biomarkers responsible for TAM resistance as well as CK-α expression, which might be linked with autophagy through a protective role. A total of 33 intracellular metabolites, including a range of amino acids, energy metabolism-related molecules and others from cell extracts of the parental cells (MCF-7), TAM-resistant cells (MCF-7/TAM) and CK-α knockdown cells (MCF-7/shCK-α, MCF-7/TAM/shCK-α...与胆碱激酶α（choline kinase-α，CK-α）表达变化及耐药性相关的代谢物，其参与细胞存活与细胞自噬（autophagy）调控机制，是乳腺癌治疗的潜在靶点。本团队此前的研究表明，细胞自噬在驱动乳腺癌细胞（breast cancer cells, BCCs）他莫昔芬（tamoxifen，TAM）耐药过程中发挥因果性作用，而CK-α敲低可促进细胞自噬，进而提升他莫昔芬耐药乳腺癌细胞的存活能力。目前尚无针对同时具备他莫昔芬耐药性与CK-α敲低特征的乳腺癌细胞代谢产物的比较研究。因此，本研究旨在筛选与他莫昔芬耐药及CK-α表达相关的差异性代谢生物标志物，这类标志物或通过保护性作用与细胞自噬通路存在关联。本研究共从亲本细胞MCF-7（parental cells）、他莫昔芬耐药细胞MCF-7/TAM（TAM-resistant cells）以及CK-α敲低细胞MCF-7/shCK-α、MCF-7/TAM/shCK-α……（CK-α knockdown cells）的细胞提取物中鉴定出33种细胞内代谢物（intracellular metabolites），涵盖多种氨基酸、能量代谢相关分子及其他组分。