Ibrahim Badr, Stange Jan, Dominik Adrian, Sauer Martin, Doss Sandra, Eggert Martin
Division of Nephrology/ Department of Internal Medicine, University Hospital Rostock, Rostock, Mecklenburg Verpommern, Germany.
Department of Anaesthesiology and Intensive Care Medicine, University Hospital Rostock, Rostock, Mecklenburg Verpommern, Germany.
PeerJ. 2020 Mar 5;8:e8568. doi: 10.7717/peerj.8568. eCollection 2020.
Albumin is the most abundant plasma protein and functions as a transport molecule that continuously interacts with various cell types. Because of these properties, albumin has been exploited by the pharmaceutical industry to improve drug delivery into target cells. The immediate effects of albumin on cells, however, require further understanding. The cell interacting properties and pharmaceutical applications of albumin incentivises continual research into the immediate effects of albumin on cells. The HepG2/C3A hepatocellular carcinoma cell line is used as a model for studying cancer pathology as well as liver biosynthesis and cellular responses to drugs. Here we investigated the direct effect of purified albumin on HepG2/C3A cell proliferation in the absence of serum, growth factors and other serum originating albumin bound molecules. We observed that the reduced cell counts in serum starved HepG2/C3A cultures were increased by the inclusion of albumin. Cell cycle analysis demonstrated that the percentage of cells in G1 phase during serum starvation was reduced from 86.4 ± 2.3% to 78.3 ± 3.2% by the inclusion of albumin whereas the percentage of cells in S phase was increased from 6.5 ± 1.5% to 14.3 ± 3.6%. A significant reduction in the cell cycle inhibitor protein, P21, accompanied the changes in the proportions of cell cycle phases upon treatment with albumin. We have also observed that the levels of dead cells determined by DNA fragmentation and membrane permeabilization caused by serum starvation (TUNEL: 16.6 ± 7.2%, ethidium bromide: 13.8 ± 4.8%) were not significantly altered by the inclusion of albumin (11.6 ± 10.2%, ethidium bromide: 16.9 ± 8.9%). Therefore, the increase in cell number was mainly caused by albumin promoting proliferation rather than protection against cell death. These primary findings demonstrate that albumin has immediate effects on HepG2/C3A hepatocellular carcinoma cells. These effects should be taken into consideration when studying the effects of albumin bound drugs or pathological ligands bound to albumin on HepG2/C3A cells.
白蛋白是血浆中含量最丰富的蛋白质，作为一种转运分子，它持续与多种细胞类型相互作用。由于这些特性，制药行业利用白蛋白来改善药物向靶细胞的递送。然而，白蛋白对细胞的即时作用仍需进一步了解。白蛋白的细胞相互作用特性和药物应用促使人们持续研究白蛋白对细胞的即时作用。HepG2/C3A肝癌细胞系被用作研究癌症病理学以及肝脏生物合成和细胞对药物反应的模型。在此，我们研究了在无血清、生长因子和其他血清来源的与白蛋白结合分子的情况下，纯化的白蛋白对HepG2/C3A细胞增殖的直接影响。我们观察到，在血清饥饿的HepG2/C3A培养物中，加入白蛋白后细胞计数减少的情况有所改善。细胞周期分析表明，血清饥饿期间处于G1期的细胞百分比从86.4±2.3%降至78.3±3.2%，而处于S期的细胞百分比从6.5±1.5%增加到14.3±3.6%。用白蛋白处理后，细胞周期抑制剂蛋白P21显著减少，同时细胞周期各阶段比例发生变化。我们还观察到，由血清饥饿引起的DNA片段化和膜通透性测定的死细胞水平（TUNEL法：16.6±7.2%，溴化乙锭法：13.8±4.8%），加入白蛋白后无显著变化（11.6±10.2%，溴化乙锭法：16.9±8.9%）。因此，细胞数量的增加主要是由于白蛋白促进增殖，而不是防止细胞死亡。这些初步发现表明，白蛋白对HepG2/C3A肝癌细胞有即时作用。在研究与白蛋白结合的药物或与白蛋白结合的病理配体对HepG2/C3A细胞的影响时，应考虑这些作用。
