1.Cell Journal: Vitamin Cand L-Proline regulate the behavior of pluripotent stem cells
doi:10.1016/j.stemcr.2016.11.011
In a newstudy, researchers from Italy, the Netherlands and the United States found thatvitamins and amino acids play a key role in pluripotent stem cells. Thisfinding may provide new insights in cancer biology and regenerative medicine.
Vitaminsand amino acids play a key role in the regulation of epigenetic modification ofthe progression of diseases (such as cancer). It may have an impact on futurecancer biology research.
"We found that two metabolites, Vitamin C andL-proline, play an important role in controlling stem cell behavior," saidGabriella Minchiotti, a researcher at the Italian Research Council researcher."This study confirms the existence of The most advanced pluripotentembryonic stem cells are pushed by vitamin C into a more immature 'naive'state, and in the presence of L-proline they are forced to obtain a 'primed'State.Therefore, vitamin C and L-proline have an opposite effect on embryonicstem cells, and this is associated with their ability to modify DNA, whichchanges the methylation of DNA to regulate gene expression, but not Change itssequence. "
2.Cell Rep: The latest studyfound an important mechanism for the spread of breast cancer
doi:10.1016/j.celrep.2016.12.079
Tounderstand why breast cancer cells are transferred, researchers from theUniversity of Michigan have studied the primary and metastatic lesions ofbreast cancer. In this new study they found a protein that promotes the spreadof breast cancer cells in the tumor microenvironment. The protein belongs tothe tyrosine kinase receptor family, and the family of receptor proteins play arole in many cancers, and scientists have been developing inhibitors oftargeting such proteins.
About 20%of breast cancer patients will undergo distant metastases, and researchers hopeto prevent cancer cells from transferring or once in the event of aneutralization of the transfer, which can improve the patient's survival rate.
In a newstudy published in the International Academic Journal Cell Reports, theresearchers obtained tissue samples from diseased parts of the patient andstudied the cells around the tumor. There are many cell types in the tumormicroenvironment, including immune cells, vascular system cells, andmesenchymal stem cells.
Researchershave found that mesenchymal stem cells can affect metastases. They found thatDDR2, a protein that could open up the way for breast cancer cells to helpspread and activate cancer to promote cancer cell growth. When DDR2 appears oncells, the researchers can observe that cancer cells, mesenchymal stem cellsand collagen are ordered to efficiently form a metastatic foci; when DDR2 isremoved on cells, cancer cells and collagen will become disorganized The migrationof cancer cells and the formation of metastatic foci.
The researchers also studied DDR2 knockout mice, which hadless metastatic tumors and showed no signs of orderly arrangement of the cells.
3.Nat Cell Biol: Scientistshave found that new subtypes of breast stem cells may be associated with theoccurrence of malignant breast cancer
doi:10.1038/ncb3471
Researchersat the Walter and Irisha Institute (WEHI) in Australia use advanced cytology,bioinformatics and imaging techniques to reveal a long-lived stem cell type inthe breast that is associated with breast growth during pregnancy.
The newlydiscovered stem cells are able to respond to ovarian hormones - progesteroneand estrogen, and are also associated with a risk of breast cancer. The resultsof the study were published in the international academic journal Natue CellBiology.
Articleauthor Dr. Nai Yang Fu said they were based on previous studies on breast stemcells and found stem cells with different functions. "We observed thegenes that were expressed in these stem cells and found that the stem cellsubpopulations were differentiated according to the expression of the twogenes, which were Tetraspanin8 and Lgr5. According to the expression levels ofthese two proteins on the cell surface , We can divide the stem cells intothree different groups, "Dr said Fu.
Researchersuse three advanced technologies, including three-dimensional imaging, foundthat three groups of stem cells located in different positions of the breastfunction is also different.
"Wefocused on a stem cell subsets that are highly expressed by Tetraspanin8 andLgr5, which are located near the nipple of the breast," Dr Rios said.Visvader Professor said that these stem cells in normal circumstances in adormant state, to maintain life in the original position. "But when theyare stimulated by progesterone and estrogen will be awakened to quicklygenerate new breast cells," she said.
The study also found that Tetraspanin8 and Lgr5overexpressing stem cells have many similarities to a subtype of low-expressionsubtypes of triple negative breast cancer - the low expression subtypes ofclaudin. "Compared to other types of breast cancer, claudin low expressionsubtypes have a high risk of recurrence after treatment, leading to poorprognosis of patients," Professor Visvader said.
4.Science: organelledistribution determines the fate of stem cells
doi:10.1126/science.aah4701
When mostcells divide, they only produce more of their own. But the stem cellsresponsible for repairing damaged tissue face a choice: they can produce morenew stem cells, or differentiate into skin cells, hepatocytes or almost anyparticular cell type within the body.
In a newstudy, researchers from the University of Rockefeller found that this criticaldecision depends on whether the organelles like organelles are properlydistributed within the dividing stem cells.
As theoutside of the skin, the epidermis provides a protective barrier to the bodywhile the stem is located deep inside it. During development, stem cellsundergo an asymmetric division, producing two daughter cells: a subcellmaintains the ability to self-renew, remains in the interior, and the otherdaughter cells undergo differentiation, migrating and becoming part of theouter epidermis.
Bystudying the development of mouse skin, the first author Amma Asare devised amethod to identify genes that assist in guiding the maintenance of dry daughtercells and the differentiation of daughter cells in equilibrium. A particularprotein, Pex11b, caught her attention. It binds to the peroxisomal membrane.Peroxisomes are organelles that aid in the release of energy from food.
Asareconfirms that the mechanism of action of this protein seems to be to ensurethat the peroxisomes are in the proper position, so that they can bedistributed between the two daughter cells. In dry cells lacking Pex11b,peroxisomes can not be evenly distributed, and in some cases a daughter cellacquires all peroxisomes while the other daughter cells do not acquire anyperoxisomes. For stem cells that have been destroyed by the distribution ofperoxisomes, cell division takes longer and the spindle is not properly alignedas a structure of the isolate cell genetic material.
Asare found that the final result of removing Pex11b instem cells was that fewer daughter cells could differentiate into mature skincells.
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