Bottone Maria Grazia, Soldani Cristiana, Fraschini Annunzia, Croce Anna Cleta, Bottiroli Giovanni, Camboni Tania, Scovassi Anna Ivana, Pellicciari Carlo
Dipartimento di Biologia Animale, Università degli Studi di Pavia, Pavia, Italy.
Histochem Cell Biol. 2009 Mar;131(3):391-9. doi: 10.1007/s00418-008-0538-0. Epub 2008 Nov 14.
Photosensitization of tumor cells after incubation with Rose Bengal acetate (RB-Ac) induces multiple organelle photodamage followed by apoptotic cell death. We used immunocytochemical techniques in multicolor fluorescence microscopy to elucidate whether this occurs through the simultaneous activation of different apoptotic pathways, in HeLa cells. We detected in situ the activated forms of caspases 9 and 3, and the translocation from the mitochondria to the nucleus of the apoptosis inducing factor; DNA electrophoretic techniques were also used to assess the occurrence of nuclear DNA cleavage into either high- or low-molecular-weight fragments. Both the caspase-dependent and caspase-independent apoptotic pathways are activated. The genomic DNA is degraded into high molecular weight molecules only, without the formation of oligonucleosome-sized fragments. The ability of RB-Ac to induce the simultaneous release of apoptogenic signals from different photodamaged organelles makes it an especially powerful cytotoxic agent.
用醋酸孟加拉玫瑰红（RB-Ac）孵育后，肿瘤细胞的光敏化会引发多个细胞器的光损伤，随后导致细胞凋亡死亡。我们运用免疫细胞化学技术结合多色荧光显微镜，以阐明在HeLa细胞中这一过程是否通过同时激活不同的凋亡途径而发生。我们原位检测了半胱天冬酶9和3的激活形式，以及凋亡诱导因子从线粒体向细胞核的转位；还使用了DNA电泳技术来评估核DNA断裂成高分子量或低分子量片段的情况。半胱天冬酶依赖性和非依赖性凋亡途径均被激活。基因组DNA仅降解为高分子量分子，未形成寡核小体大小的片段。RB-Ac能够从不同的光损伤细胞器同时释放凋亡信号，使其成为一种特别强大的细胞毒性剂。
