Ullah Matti, Aoudjeghout Warda, Pimpie Cynthia, Pocard Marc, Mirshahi Massoud
CAP-Paris Tech., INSERM U1275, Hôpital Lariboisière, 2, rue Ambroise-Paré, 75010 Paris, France.
Cancers (Basel). 2020 Sep 18;12(9):2661. doi: 10.3390/cancers12092661.
Cancer is a result of "aggressive" division and uncontrolled proliferation of the abnormal cells that survive attack by immune cells. We investigated the expression of HLA-G and PD-L1 with the different stages of cancer cell division along with their role in the interaction of immune cells in vitro. Ovarian cancer (OVCAR-3) and chronic myeloid leukemia cell line (K-562) are used for this study. The correlation of protein expression with percentage of cells in each phase (G1, S and G2 phase) was evaluated through FACS. Cells were synchronized in G1, G2 and mitotic phase to evaluate gene (RT-qPCR) and protein expression (FACS). Real-time immune cell attack (RTICA) analysis with PBMCs (peripheral blood mono-nuclear cells) and cancer cells were performed. We found that cells expressing higher levels of HLA-G and PD-L1 are mainly in G2 phase and those expressing lower levels are mainly in G1 phase. Evidently, the higher expression of the two proteins was observed when synchronized in mitotic phase as compared to low expression when synchronized in G1 phase. RTICA analysis showed the presence of HLA-G delayed the lysis of the cells. In conclusion, the cancer cell can escape from immune cells in division stage that suggests the impact of mitosis index for cancer immunotherapy.
癌症是免疫细胞攻击后存活下来的异常细胞“侵袭性”分裂和不受控制增殖的结果。我们研究了HLA-G和PD-L1在癌细胞分裂不同阶段的表达及其在体外免疫细胞相互作用中的作用。本研究使用卵巢癌（OVCAR-3）和慢性粒细胞白血病细胞系（K-562）。通过流式细胞术评估蛋白质表达与各期（G1、S和G2期）细胞百分比的相关性。将细胞同步于G1、G2和有丝分裂期，以评估基因（RT-qPCR）和蛋白质表达（流式细胞术）。对外周血单个核细胞（PBMC）和癌细胞进行实时免疫细胞攻击（RTICA）分析。我们发现，表达较高水平HLA-G和PD-L1的细胞主要处于G2期，而表达较低水平的细胞主要处于G1期。显然，与G1期同步时的低表达相比，有丝分裂期同步时观察到这两种蛋白质的表达较高。RTICA分析表明，HLA-G的存在延迟了细胞的裂解。总之，癌细胞在分裂阶段可逃避免疫细胞，这提示有丝分裂指数对癌症免疫治疗的影响。
