| Summary: | 碩士 === 國立交通大學 === 生物科技學系 === 103 === Fluorescent nanodiamond (FND) can emit bright red fluorescence without photo-bleaching and has great biocompatibility for biomedical applications. FND can be taken into cells by endocytosis; however, the transportation and distribution of FNDs in the mitosis remains unclear. In this study, we investigated the mechanisms of cellular uptake and transportation of FNDs in the mitotic phases of HCT116 colorectal cancer cells. We found that epidermal growth factor receptor (EGFR) proteins interacted with FNDs in the mitotic phases of HCT116 cells. Histone deacetylase 6 (HDAC6) proteins located at spindle poles that were also co-localized with FNDs. The interaction of FNDs with EGFR and HDAC6 was separated into two daughter cells. Moreover, FNDs were also co-localized with lysosomes in the mitotic phases. Aurora A is an important mitotic kinase that regulates mitosis and cancer progression. However, we found that Aurora A protein located in the centrosomes of mitotic phases but not directly interacted to FNDs. We further investigated an Aurora A inhibitor MLN8237 (Alisertib) on the effects of cellular uptake and transportation of FNDs. FNDs did not alter the phospho-Aurora A (Thr-288) protein levels and mitotic progression; conversely, MLN8237 decreased the phospho-Aurora A (Thr-288) proteins and cell viability and induced abnormal mitosis and polyploidy. Interestingly, co-treatment of MLN8237 and FNDs enhanced the increase of FND levels of HCT116 cells by flow cytometry and confocal microscopy. The accumulation of FNDs in the MLN8237-induced multinucleated cells was further confirmed by transmission electron microscopy (TEM). Together, we demonstrate that transportation of FNDs in the lysosomes can be regulated by the EGFR and HDAC6 pathway during the mitotic progression. Furthermore, the inhibition of Aurora A by MLN8237 will increases the accumulation of FNDs in the abnormal mitotic phases or multi-nuclear cells.
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