肿瘤细胞,基因变异 z-bo 2020-09-15 331

　　Just as no two people have the same genetic makeup, in breast cancer patients, no two tumor cells have the same genome. According to a new study, different breast cancer subtypes also have a variety of variant tumors. This discovery has important implications for the diagnosis and treatment of breast cancer, and helps breast cancer patients who have developed chemotherapy resistance. Related papers were published in the recently published "Nature" magazine.

　　The research was led by the Nicholas Navin research group, associate professor of the Department of Genetics at the University of Texas. According to the physicist organization network recently reported that they have developed a new sequencing method called "nuclear sequencing" that can sequence the genome of a single cell. This method, combined with single-cell molecular sequencing, can analyze thousands of cells.

　　In fact, the growth rate of different tumor cells is also very different. "We found that at different stages of tumor growth, there are two distinct'molecular clocks' operating." Navin said, "The tumor cells of triple-negative breast cancer have an increased mutation rate, and estrogen receptor positive (ER+ ) This is not the case with breast cancer tumor cells."

　　About 75% of breast cancers are of the ER+ type, which grows with the increase of estrogen. These patients are usually treated with estrogen therapy. Triple-negative breast cancer accounts for approximately 15% to 25% of all breast cancers and usually does not respond to hormone therapy or standard chemotherapy.

　　"A common problem in the field of single-cell genomics is that it is impossible to confirm the mutations detected in a single cell." said Wang Yong (transliteration), the first author of the paper and a postdoctoral researcher in the Department of Genomics. "To deal with this problem, we combined Single-cell sequencing and targeted single-cell deep sequencing. This can not only confirm the mutation, but also accurately detect the mutation frequency of thousands of cells."

　　An important question in chemotherapy is whether the mutations in certain cells in the tumor are resistant mutations, that is, mutations caused by treatment. "Although this problem has been studied in bacteria for decades, it is still poorly understood in most human cancers." Navin said, "Our data show that before chemotherapy, there are already a large number of tumor cells. Diversified mutations. Therefore, we hope that genomic diversity testing can play a role in prognosis, identifying which patients may develop chemotherapy resistance."

　　Researchers pointed out that large population sequencing studies on breast tumors have identified many major variants, but the diversity of variants is still poorly understood. This research increases people's understanding of "genomic diversity" within tumors. Genomic diversity is very useful in clinical practice and can be used to predict tumor invasion, metastasis, and patient survival.