Cancer cell: New discovery: Highly plastic cell states reveal the mechanisms of resistance of cancer cells.

!---- introduction: As we all know, the drug treatment of cancer has become an important treatment, in recent years, a variety of new anti-cancer drugs have emerged, but also achieved a certain therapeutic effect.However, many anti-cancer drugs tend to work well when they start using them, but over time they gradually become ineffective or even ineffective, which is often referred to as tumor resistance.has long been a major obstacle to long-lasting remission or cure of chemotherapy.Although the tumours may shrink quickly after chemotherapy, many times they eventually grow back.scientists once believed that unique genetic mutations in tumors were the basis of resistance.but now they are increasingly looking at other non-gene changes in cancer cells to explain their adaptability., for example, one way cancer cells develop resistance is to change their identity.prostate cancer cells that are sensitive to hormone blocking therapy may become hormone-in-demand types.not specific mutations drive them, and identity changes like this come from changes in gene expression -- cells turn specific genes on or off. as a result of these changes, the cell composition of a single tumor becomes very different.this heterogeneity poses a challenge to treatment because a single drug is unlikely to work on so many different cell types.recently, a team of researchers from the Sloan Kettering Institute, the Koch Institute of Integrated Cancer at the Massachusetts Institute of Technology, and the Karaman Cell Observatory at the Broad Institute found that this tumor heterogeneity can be traced back to a common source: a particularly flexible cell state that is a subgroup of tumor cells that can produce many different cell types.the study was published July 23 in the journal Cancer Cells. "Highly malleable cell states are the starting point for most of the heterogeneity we see in tumors, a bit like busy intersections on many roads, with highly malleable cell states at the center," said Tuomas Tammela, an assistant member of theSKI's cancer biology and genetics program and the paper's author."Because this cell state produces almost all cell heterogeneity in the tumor, it is an attractive target for potential therapies."the special tumors tested by researchers were lung cancer tumors that grew in mice. "It's a surprise to find this unusual cell state," said Jason Chan, a medical scientist whoat Tammela Labs and one of the lead authors of the paper.this highly malleable cell state is a whole new thing.When we see it, we don't know what it is because it's so different.from the source of cancer, it is not like normal lung cells, nor is it like lung cancer.it has the characteristics of embryo-layer stem cells, cartilage stem cells, and even kidney cells mixed together." plot summary However, he and his colleagues found these cells in every tumor they examined, suggesting that they play a very important biological role.a roadmap for cell presentation researchers to identify these highly malleable cells by using a relatively new laboratory technique, single-cell RNA sequencing (scRNA-Seq).the technique allows researchers to "snapshot the gene expression spectrum of individual cells" -- revealing which genes are turned on and those that are turned off.using scRNA-Seq as tumors change over time, they can see when and how tumors evolve with different cell types.based on the data, the researchers were able to map which cells came from which.this highly malleable cell state persists throughout the evolution of tumors and persists throughout tumor growth.in fact, Dr. Tammela said, "this is the only cell state we found in every tumor."" is not the ability of stem cells to differentiate into other cells with different characteristics, and is a well-known feature of stem cells.stem cells play an important role in embryonic development and tissue repair.many scientists believe that cancer is caused by specific cancer stem cells.but Dr Tammela and his colleagues do not believe that these highly malleable cells are stem cells.when they compared the genetic expression characteristics of these highly malleable cells with normal stem cells or known cancer stem cells, these characteristics did not match at all. they look completely different. unlike stem cells, they do not exist at the beginning of tumor growth. they only appeared later. Many studies before changes in drug resistance are looking for possible "drug-resistant mutations" -- genetic changes that explain the tumor's ability to resist anti-cancer drugs. some drug resistance has been discovered, but more often the basis of resistance remains a mystery. new findings offer a possible answer to the puzzle. "Our model may explain why certain cancer cells are resistant to treatment, and we are not able to identify the genetic basis of this resistance," said Chan. important thing, not all cells in the tumor are adapting. researchers believe that by combining chemotherapy drugs with new drugs for these highly malleable cells, it is possible to avoid the emergence of drug resistance and provide more lasting relief. .