Cancer is a complex disease that involves a series of gene-environment interactions. Multiple pathways are involved in cancer, such as DNA repair, epigenetic alterations, apoptotic and immune functions. One major characteristic of cancer is uncontrolled growth of the cells in the body. If we can find ways to control the rapid growth of cancer cells, it may lead to new cancer therapies. The cell cycle, or called cell-division cycle, is the sequence of events by which cells grow and divide. The stages of the cell cycle are divided into two major phases, a preparatory phase and a division phase. During the preparatory phase, all the preparations are done. A dividing cell spends most of its time in the preparatory phase. Now, a study (Tudor-SN–mediated endonucleolytic decay of human cell microRNAs promotes G1/S phase transition) shows that a protein called Tudor-SN is associated with the preparatory phase and that inhibiting the protein could slow cancer cell division. (Cusabio provides a variety of proteins such as Recombinant Itgb5.) The researchers found that the endonuclease Tudor-SN is critical for the preparatory phase. Tudor-SN protein is a multifunctional protein implicated in a variety of cellular processes. Lead researcher Dr. Reyad Elbarbary noted that the levels of Tudor-SN are higher in cancer cells compared with in healthy cells. When they removed Tudor-SN from cancer cells using the CRISPR-Cas9 gene editing technique, cancer cell growth was significantly delayed. Furthermore, Tudor-SN affects the cell cycle by regulating microRNAs, small non-coding RNA molecules that function to downregulate gene expression. The researchers found that functional microRNAs are degraded in human cells by Tudor-SN, and that loss of Tudor-SN leads to a decrease in many microRNA molecules, which in turn downregulate genes critical for cell growth. Taken together, the findings suggest that "targeting TSN nuclease activity could inhibit pathological cell proliferation." There already are compounds that inhibit Tudor-SN and might have anti-cancer effect. Further research on the function of Tudor-SN is necessary, which may enable scientists to find better ways to target it. The findings are described online today in the journal Science. Researchers of the study include Reyad Elbarbary, Keita Miyoshi, Jason Myers, John M. Ashton, and Lynne Maquat at the University of Rochester, Peicheng Du at Rutgers University, and Bin Tian at Rutgers New Jersey Medical School.
