RESPONSE OF HeLa CELLS TO MITOMYCINE C. I. CELL DIVISION
Using light microscopy, time-lapse imaging, and digital image analysis, the effect of mitomycine C (10 μg/ml) on HeLa-M cells has been studied. It has been shown that, after a 2 h contact with mitomycine, the cells could be separated into 2 groups: M-1 — the functional cells surviving after division but non-entering mitosis any more; M-II — the cells entering mitosis but incapable to finish it; they are lost. Mitomycine C is known to specifically block DNA replication being located in the DNA minor groove. It should inhibit РНК synthesis if one follows the standard hypothesis of a transcription bubble formation. However, increasing the cell and nucleolus area during the M-I cell growth suggests that RNA and protein synthesis is not blocked. The author concludes that the presented data con firm his hypothesis about RNA synthesis in the major DNA groove (Petrov, 2006).