Targeting MDR and NEK1 for Cancer Therapeutics
Author:Marlen Tagle Rodriguez
Mentor:Phang-Lang Chen, Associate Professor, Department of Biological Chemistry, University of California, Irvine
Some of the common treatments against cancer include chemotherapy and radiation. However, in several cancer types it has been found that after exposure the cancerous cells become resistant to these treatments. Examples include some forms of breast, lung, colon, prostate and renal cell cancers. In these scenarios, even excision of most of the cancerous growths is not sufficient for recovery because not all of the cancerous cells may be removed and these continue to propagate. Once these remaining cells become immune to chemotherapy and radiation, the individual faces slim chances of recovery and survival. Here, we explore a method to counter the cells’ immunity against chemotherapy by making them susceptible through control of gene expression. In a previous study, it was determined that Nek1 is highly expressed in RCC compared to normal cells and is essential in the cells’ DNA damage response. We hypothesize that in cancer cells Nek1 prohibits apoptosis through phosphorylation and thus enables the cells to survive after exposure to genotoxic agents. A multidrug resistance gene, MDR, is also found in excess in renal carcinoma cells and has also been shown to play an important role in these cancer cells’ survival in response to chemotherapeutics. When these two genes are overexpressed in cancer cells they prevent apoptosis after DNA damage and pump out the chemotherapy drugs since MDR works as an efflux pump. We propose to enhance the efficacy of chemotherapeutics by knocking down both Nek1 and MDR. In order to do this LKO MDRi and Nek1i plasmids were constructed and inserted into cultured 293T human kidney cells. HK2 kidney cells and A498 kidney carcinoma cells were then infected with the virus produced which knocked down the targeted genes. Once the genes were knocked down, both kidney cell strains were treated with 5FU, a common chemotherapeutic drug.