Mitochondrial proteomics with siRNA knockdown to reveal ACAT1 and MDH2 in the development of doxorubicin-resistant uterine cancer

Perhaps some of the more challenging issues facing current efforts to treat cancer, and all diseases for that matter, are side effects and drug resistance. When researchers discover an effective treatment, there is always the risk that when put into use, some patients are resistant to it and the therapeutic effects are not felt or the drug has an overall negative effect on their health. This is very much the case for doxorubicin-induced chemotherapy. Doxorubicin is a primary anti-cancer drug, but has clear negative side effects. It has been shown to disturb DNA replication and also inhibits topoisomerase 2, which leads to a breakage of DNA double strands, preventing DNA synthesis. In addition, one of the major difficulties with doxorubicin is that, while it has proven effective in killing cancer cells, it also has the possibility to induce cell death in other non-harmful cells. Another issue with doxorubicin is resistance. Resistance has been reported in patients of breast cancer, lung cancer, leukemia, osteosarcoma and uterine cancer. There are many explanations for this, but one of them, which is the focus of the study by Lo et al., is the alterations that occur in numerous proteins. Because of this, a proteomic strategy to determine resistance proteins is a logical approach in this field of research.

In this study, to discover low abundance proteins, sub-cellular proteomic analyses based on purification of mitochondrial proteins were performed. Better understanding the connection between mitochondria and doxorubicin-induced chemotherapy resistance is important as mitochondria can play a key role in the development of cancer resistance proteins and can help to explain the development of chemotherapy resistance. To facilitate their study, Lo and his colleagues needed to measure mitochondrial membrane potential, which was achieved by introducing the fluorescent indicator, JC-10™. What makes JC-10™ such an effective tool in a study like this is due to its color variation depending on the excitement ratio. This allows researchers to get an accurate picture of what is happening within the mitochondrial membrane. With this type of accuracy, researchers can be confident that what they are measuring is indeed what they were intending to measure, and can also be sure that the results obtained are reliable.

Ultimately, Lo and his team found that numerous proteins, including ACAT1 and MDH2, are involved in various drug-resistance-forming mechanisms. Their results provide very useful insight into what causes chemotherapy resistance and can help guide further research on treatment options. The use of the JC-10™ indicator for studying mitochondrial membrane potential played a pivotal role in determining the results of this study. Its high signal to background ratio helps keep the signals clear and the results easy to read thus minimizing the risk of obtaining faulty results and strengthening the study's veracity.

References

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1. Lo, Yi‐Wen, et al. "Mitochondrial proteomics with siRNA knockdown to reveal ACAT1 and MDH2 in the development of doxorubicin‐resistant uterine cancer." Journal of cellular and molecular medicine 19.4 (2015): 744-759.