Tissue & Cell 36 (2004) 197–210 Autoschizis: a new form of cell death for human ovarian carcinoma cells following ascorbate:menadione treatment Nuclear and DNA degradation Jacques Gilloteaux a,b,∗ , James M. Jamison b , Heather E. Lorimer c , David Jarjoura d , Henryk S. Taper e , Pedro B. Calderon e , Deborah R. Neal b , Jack L. Summers b a Department of Anatomy, American University of the Caribbean, School of Medicine, Campus St. Maarten, M.E.I.O. Inc., Ponce de Leon Boulevard 901, Suite #401, Coral Gables, FL 33135, USA b Department of Urology, Summa Research Foundation, Summa Health System, Akron, OH 44304, USA c Department of Biological Sciences, Youngstown State University, Youngstown, OH 44555, USA d Office of Biostatistics, Division of Community Health Sciences, NE Ohio, Universities College of Medicine, Rootstown, OH 44272, USA e Unit of Pharmacokinetics, Metabolism, Nutrition and Toxicology, Université Catholique de Louvain, Brussels-Woluwé 1200, Belgium Received 25 May 2003; received in revised form 20 January 2004; accepted 27 January 2004 Abstract Microscopic aspects, densitometric evaluation of Feulgen-stained DNA, and gel electrophoresis of total DNA have been used to elucidate the effects of 1, 2, and 3 h VC (ascorbic acid), VK 3 (menadione), and combined VC:VK 3 treatments on the cellular and nuclear morphology and DNA content of a human ovarian carcinoma cell line (MDAH 2774). Optical densitometry showed a significant decrease in cancer cell DNA content directly related to VC and VC:VK 3 treatments while VK 3 and VC:VK 3 treated cells exhibited cytoskeletal changes that included self-excision of cytoplasmic pieces with no membranous organelles. Nuclei decreased in size and exhibited poor contrast consistent with progressive decondensation of their chromatin. Degraded chromatin was also detected in cytoplasmic autophagosomes. Nucleoli segregated their components and fragmented into small pieces. Gel electrophoretic analysis of total DNA revealed evidence of generalized DNA degradation specific to treated tumor cells. These results are consistent with previous observations [Scanning 20 (1998a) 564; Ultrastruct. Pathol. 25 (2001b) 183; J. Histochem. Cytochem. 49 (2001) 109] which demonstrated that the VC:VK 3 combination induced autoschizic cell death by a series of cytoplasmic excisions without organelles along with specific nuclear ultrastructural damage. © 2004 Elsevier Ltd. All rights reserved. Keywords: Ovarian carcinoma; DNA; Microscopy; Nucleus; Ascorbate; Menadione; Cell death 1. Introduction An estimated 25,400 new neoplasms of the ovary will be diagnosed during 2003 in the United States. This figure represents about 5% of new female cancer cases (Jemal et al., 2003). Ovarian cancer occurs in American women with an incidence rate of 9.4 cases per 100,000 for those under 65 years of age and an incidence of 54.8 cases per 100,000 after the age of 65 years. Because of its late detection, ovarian carcinoma is among the 10 most lethal malignancies with only 50% of cancer patients surviving 5 years after treatment (Ries, 1993). ∗ Corresponding author. Tel.: +1-599-545-2298; fax: +1-599-545-2440. E-mail address: jagillot@yahoo.com (J. Gilloteaux). Taper and coworkers (Taper et al., 1971, 1987, 1992, 1996; Noto et al., 1989; De Loecker et al., 1993; Calderon et al., 2002) demonstrated that co-administration of sodium ascor- bate (Vitamin C or VC) and 2-methyl-1,4-naphthoquinone (Vitamin K 3 or VK 3 ) to a variety of carcinoma cell lines and tumors in a VC:VK 3 ratio of 100:1 resulted in equivalent an- tineoplastic activity at concentrations that were 10–50 times lower than when either vitamin was administered alone. Daoust and Taper have shown these tumors exhibit a char- acteristic loss of one or more DNases and RNases and these nucleases could be reactivated by a number of agents, includ- ing Vitamins C and K 3 (Daoust and Amano, 1963; Taper, 1967, 1980). Selective and sequential reactivation of DNase I by VK 3 and DNase II by VC, when the vitamins were ad- ministered in combination, resulted in synergistic degrada- tion of DNA and tumor regression (Taper et al., 1987, 2001) and has been implicated along with oxidative stress resulting 0040-8166/$ – see front matter © 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.tice.2004.01.006