A study about the impaired mitochondrial membrane potential and nuclear body formation, and their relationship with the induction of cell senescence and cell death

用荧光标记的S1-1亚型特异性抗体和PML亚型特异性抗体，我们检查了培养的人正常细胞（TIG 3S）、HeLa细胞、各种正常大鼠组织和各种人肿瘤组织的核体与相应的正常组织。在年轻的TIG 3S细胞中，S1-1核小体很少，而PML 2、4、5、6核小体较多。此外，证实了S1-1和PML 6核体的共定位。在HeLa细胞中，几乎没有观察到S1-1核小体。此外，还观察到S1-1和PML蛋白的显著胞浆定位，PML 2和PML 6的显著核小体，以及PML 4和PML 5的罕见核小体。我们证实了罕见的S1-1核小体分裂年轻的TIG 3S和HeLa细胞。另外，年轻的TIG 3S和HeLa细胞中S1- 1 p110蛋白水平很低，相反，S1- 1 p130蛋白水平很高。此外，HeLa细胞的S1- 1 p130水平比TIG 3S细胞高3倍。PML和S1-1（RBM 10）具有许多被CK 2和PKC磷酸化的位点，并且HeLa细胞具有比正常细胞显著更高的CK 2活性。因此，被CK 2磷酸化（PML的S517）的PML同种型在蛋白酶体中降解。然而，S1- 1 p130（RBM 10变体-1）即使在HeLa细胞中也非常稳定。HeLa细胞和TIG 3S细胞经PKC或CK 2抑制剂处理后，S1-1核小体明显增多。这表明，在活跃分裂的细胞中，S1-1核体的组装通过它们被CK 2磷酸化而受到抑制。在PKC或CK 2抑制剂的存在下，但不是CDK 2抑制剂，HeLa或TIG 3S细胞的细胞分裂被强烈地损害，并且药物促进细胞死亡。我们的研究结果表明，S1-1和PML核体调节细胞生长并促进细胞死亡途径

With fluorescently labeled S1-1 isoform specific antibodies and PML isoform specific antibodies, we examined the nuclear bodies of cultured human normal cells (TIG3S), HeLa cells, various normal rat tissues, and various human tumor tissues with the corresponding normal tissues. In young TIG3S cells, S1-1 nuclear bodies were rarely observed, but PML2, 4, 5, 6 nuclear bodies were observed significantly. Furthermore, co-localization of S1-1 and PML6 nuclear bodies was confirmed. In HeLa cells, S1-1 nuclear bodies were hardly observed. In addition, the remarkable cytoplasmic localization of S1-1 and of PML protein, significant nuclear bodies of PML2 and PML6, and rare nuclear bodies of PML4 and PML5 were observed. We confirmed the rare S1-1 nuclear bodies in dividing young TIG3S and HeLa cells. In addition, the S1-1p110 protein levels of young TIG3S and HeLa cells were very low, on the contrary, the S1-1p130 protein was at very high levels. Furthermore, the S1-1p130 level of HeLa cells was 3-fold higher than TIG3S cells. PML and S1-1(RBM10) have many phosphorylation sites by CK2 and PKC, and HeLa cells have significantly higher activity of CK2 than normal cells. Thereby, the PML isoforms which are phosphorylated (S517 of PML) by CK2, degrade in the proteasomes. However, S1-1p130 (RBM10 variant-1) was very stable even in HeLa cells. HeLa and TIG3S cells, which administered with PKC or CK2 inhibitor, significantly developed the S1-1 nuclear bodies. This suggests that the assembly of S1-1 nuclear bodies was suppressed through their phosphorylation by CK2 in the actively dividing cells. In the presence of PKC or CK2 inhibitor, but not CDK2 inhibitor, cell division of HeLa or TIG3S cells was strongly impaired, and the drugs promoted cell death. Our results suggest that S1-1 and PML nuclear bodies regulate the cell growth and promote the cell death pathway