c-Myc inhibitor blocks proliferation of human ovarian cancer cells by inducing apoptosis and cell cycle arrest as reported by Cellometer Vision

Introduction

The oncogene c-Myc is frequently overexpressed in ovarian carcinomas [1]. The small molecule c-Myc inhibitor, 10058-F4, was investigated here to evaluate its effects on ovarian cancer cell growth as well as its mechanism of action [2]. The inhibitor’s impact on apoptosis, cell cycle, cell colony formation, ROS generation, and cell viability were examined in Hey and SKOV3 cell lines. These findings suggest that small molecule c-Myc inhibitors may be a promising strategy for future ovarian cancer therapies.

Materials and Methods

Cell cycle analysis

Hey and SKOV3 cell lines (both human ovarian cancer) were plated in 96-well plates and treated with the small molecule c-Myc inhibitor 10058-F4 for 48 hours. Cells were fixed, washed, and stained with propidium iodide (PI). The cells in each phase of the cell cycle were imaged and analyzed using Nexcelom’s Cellometer Vision.

Apoptosis analysis

Hey and SKOV3 cell lines were plated in 6-well plates and treated with 10058-F4 at various doses for 24 hours. Cells were rinsed and resuspended with buffer including FITC-conjugated Annexin-V and PI. The cells were evaluated for percent apoptosis using Cellometer Vision with VB-535-402 (FITC; EX: 470nm, EM: 535nm) and VB-660-502 (PI; EX: 540nm, EM: 660nm).

*Note:  For more detailed Materials and Methods and a complete account of the entire study, please refer to the original manuscript [http://www.ncbi.nlm.nih.gov/pubmed/25143136]

Results

  • In both cell lines, 10058-F4 caused an accumulation of cells in G1 phase and a simultaneous decrease in the number of cells in S phase when compared to controls.
  • The inhibitor had no effect on the percentage of hypertetraploid phase cells in either cell line.
cell cycle analysis of Hey and SKOV3

Figure 1A and B. Cell cycle analysis of Hey (A) and SKOV3 (B) cell lines exposed to 10058-F4 (0-50μM). Dose-dependent increases in cells within the G1 phase were seen in both cell types.

  • In both cell lines, 10058-F4 induced significant, dose-dependent increases in early and late markers of apoptosis after 24 hours exposure.
apoptosis-analysis-via-Annexin-V-and-PI-staining-in-Hey-and-SKOV3

Figure 2A-D. Apoptosis analysis via Annexin V and PI staining in Hey (A, D) and SKOV3 (B, C) cell lines exposed to 10058-F4 (0-50μM). Dose-dependent increases in both early (Annexin V) and late (PI) markers of apoptosis were seen in both cell types.

Conclusions

  • c-Myc is a worthy target for anti-tumor therapies as it functions in areas of cell growth, proliferation, and differentiation and is therefore the target of many experimental therapeutics [1, 3].
  • 10058-F4 promises to overcome limitations of unsuccessful c-Myc inhibitors because it inhibits both upstream and downstream c-Myc functions.
  • 10058-F4 has been shown effective in blocking cancer cell growth in vitro and in vivo [4-7]
  • Due to the facts that few novel ovarian cancer therapies have been developed recently and 10058-F4 has proven effective across many ovarian cancer models, ovarian cancer seems an ideal application for c-Myc small molecule inhibitors.

References

  1. Dang, C.V., MYC on the path to cancer. Cell, 2012. 149(1): p. 22-35.
  2. Yin, X., et al., Low molecular weight inhibitors of Myc-Max interaction and function. Oncogene, 2003. 22(40): p. 6151-9.
  3. O’Donnell, K.A., et al., Activation of transferrin receptor 1 by c-Myc enhances cellular proliferation and tumorigenesis. Mol Cell Biol, 2006. 26(6): p. 2373-86.
  4. Gomez-Curet, I., et al., c-Myc inhibition negatively impacts lymphoma growth. J Pediatr Surg, 2006. 41(1): p. 207-11; discussion 207-11.
  5. Lin, C.P., et al., Small-molecule c-Myc inhibitor, 10058-F4, inhibits proliferation, downregulates human telomerase reverse transcriptase and enhances chemosensitivity in human hepatocellular carcinoma cells. Anticancer Drugs, 2007. 18(2): p. 161-70.
  6. Teicher, B.A., In vivo/ex vivo and in situ assays used in cancer research: a brief review. Toxicol Pathol, 2009. 37(1): p. 114-22.
  7. Zirath, H., et al., MYC inhibition induces metabolic changes leading to accumulation of lipid droplets in tumor cells. Proc Natl Acad Sci U S A, 2013. 110(25): p. 10258-63.

 

By | 2015-01-29T09:00:15+00:00 January 29th, 2015|Categories: Cellometer User Publications|Tags: , , , |0 Comments

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