Category: SSSCR

Colorectal cancer spread is among the leading causes of cancer related deaths. Usually, people die from secondary tumors that develop from colorectal cancer rather than the primary tumor itself. By the time the tumor is detected the cancer has already spread, making it extremely difficult to treat. The cancer has poor diagnosis because the cancer cells can stay dormant for long periods of time until some signal causes them to activate and start growing and dividing rapidly.
Now a study published in Stem Cell Reports suggests a possible way for targeting the cancer cells while they are dormant. According to past research, there is a stem cell in the gut that is identifiable by its unique Lgr5 receptor, which is thought be responsible to activating the tumor cells. The stem cells are called crypt base stem cells, which allow the passage of a ‘WNT’ signal that can activate the tumor cell through a cell surface receptor called Frizzled. However, until now it was not known which type of Frizzled receptor led to this activation. There are 10 different types of Frizzled receptors, and through this research the scientists have been able to demonstrate that Frizzled7 is responsible for terminating the dormancy of the tumor cell. This provides us with a novel target for attacking colorectal cancer cell even in their dormancy, which can significantly improve colorectal cancer treatments.

Article summary courtesy by Waleed Khan

Article: Medical News Today

Researchers at the University of Illinois have recently discovered epigenetic changes that might be involved in endothelial cell development. Epigenetic changes are non-genetic changes that can affect the way genes expressed. One key way epigenetic changes occur is through modification of histones, proteins around which DNA is bound. The modification involved in this case was the demethylation of histones that appears to be crucial for the conversion of stem cells into endothelial cells.
This study identified two enzymes that were necessary for the regulation of certain genes needed for the transformation of embryonic stem cells into endothelial cells. These two enzymes, KDM4A and KDM4C, are histone demethylases and alter the expression of these genes with epigenetic modifications. The researchers initially observed high levels of these two demethylases in mice during the transformation from embryonic stem cells to endothelial cells, but further corroborated this finding in zebrafish, by knocking down these enzymes in embryos and observing their inability to form blood vessels.
The researchers believe that the demethylation of histones affects a number of promoters for genes involved in endothelial cell development. This study will allow researcher to gain more knowledge about this process that researchers can then use to develop endothelial cells for uses such as tissue repair.

Article summary courtesy by Waleed Khan and Sean Ihn

Article: ScienceDaily

Reference: 
Liangtang Wu, Kishore K. Wary, Sergei Revskoy, Xiaopei Gao, Kitman Tsang, Yulia A. Komarova, Jalees Rehman, Asrar B. Malik. Histone Demethylases KDM4A and KDM4C Regulate Differentiation of Embryonic Stem Cells to Endothelial Cells. Stem Cell Reports, 2015; DOI: 10.1016/j.stemcr.2015.05.016

Despite improving prosthetic technology, people who have lost a limb still face limitations. One alternative to prosthetic limbs would be limb transplant; however, this can lead to a prolonged high risk of immune rejection, which can make life even harder. Now researchers at Massachusetts General Hospital in Boston have been able to circumnavigate this issue by growing limbs by using an individual’s own cells rather than a transplant from a donor. Limbs involve a complex system of muscles, bones, vessels and nerves and in order for them to develop and grow properly; they need a supporting structure called a matrix.

In order to establish this, the researchers stripped away cells from the forelimbs of dead rats, but preserved the vascular and neural matrix. The researchers then repopulated these with progenitor cells and allowed them to grow and develop in a bioreactor. The limb was removed from the reactor after two weeks and tested for functionality. Electrical stimulation of the muscles in the limb caused the muscles to contract appropriately and once the limb was transplanted in another rat blood started to immediately flow into the new limb. This is a great step towards artificially growing limbs and using them for transplants. The researchers are now focusing on trying to ensure that neural connections are correctly made between the nerves of the limb and of the recipient organism.

Article summary courtesy by  Waleed Khan

References:
Engineered composite tissue as a bioartificial limb graft, Harald C. Ott et al., Biomaterials, doi:10.1016/j.biomaterials.2015.04.051, published online 2 June 2015

Diabetic neuropathy is the degeneration and the demyelination of nerves, particular in the lower regions of the body, due to high blood sugar levels. Current treatment options available only mitigate the discomfort and distress of the patients, and strictly regulate blood sugar levels. This article that was published today in GEN (Genetic Engineering News) outlines the discovery from researchers from South Korea and the U.S. in regards to the novel therapeutic potential in using mesenchymal stem cells (MSC) from bone marrow to treat diabetic neuropathy. The injection of bone marrow MSCs into rats displayed successful migration of the cells to the diabetic nerves, as well as angiogenesis, re-myelination, and axonal regeneration. This study showcases the promising potential in cell therapy as a possible therapeutic option for a disease that has previously rendered diabetic patients hopeless.

Article summary courtesy by Sean Ihn

Article: Genetic Engineering News (GEN)

Researchers from La Trobe University used time-lapse microscopy to record the death of a monocyte, a kind of white blood cell. Previously, researchers believed that white blood cells randomly broke apart during death; however, this study showed that as the cell died it produced structures that are being called ‘beads’.

The cell produced a long bead like protrusions that look like beads on a string. This then breaks into individual beads. Scientists believe that not only do these beads make it easier to clear up the cell debris but they may also contain molecules that alert the other cells of the immune system of a pathogen that has infected the body. The researchers also think that certain viruses might hide in these beads and then use them to spread in the body. Another interesting thing that they found was that beads’ formation was blocked by certain antidepressants whereas a certain antibiotic can promote their formation.

Summary courtesy by  Waleed Khan

Reference: Nature Communications PDF

Researchers at the NYU Langone Medical Center recently published a study in Nature Cell Biology in which they investigate the role of ATP synthase in the development of stem cells that develop into eggs and sperms in fruit flies. ATP synthase is an enzyme present in the mitochondria that produces ATP during the process of cellular respiration to power the chemical reactions in the cell. The researchers discovered that blocking the action of ATP synthase prevented the development of the stem cells responsible for germ cell development. Since ATP synthase is involved in the process of oxidative phosphorylation, the researchers wanted to determine whether ATP synthase or the process of oxidative phosphorylation were responsible for stem cell development.

They tested this by blocking other enzymes involved in the pathway, but they found that it did not stop stem cell development. As a result the researchers were able to conclude that ATP synthase played a role in this process. In fact disrupting any of the 13 proteins involved in ATP synthase disrupted stem cell development. The research also shows that ATP synthase could be involved in the development of cristae, folds in the inner membrane of mitochondrion, as the stem cell divides. Previous studies have shown that often mitochondria with faulty cristae have faulty ATP synthase; however, this study was able to provide a more concrete proof of this. The researchers are now interested in investigating the exact mechanism by which ATP synthase controls cristae development in the mitochondria.

Article summary courtesy by Waleed Khan

Article: Medical News Today

Reference: Nature

Recently, scientists Cedars-Sinai Medical Center in Los Angeles, CA, have shown that they can slow down vision loss due to AMD by a single stem cell injection. AMD (Age-related macular degeneration) is a degenerative disease that occurs due to the deterioration of the macula, the central part of the retina that is responsible for sensing light. People who suffer from AMD gradually lose their vision completely and there is no known cure for this condition.
But scientists at Cedars-Sinai Medical Center have been able to significantly slow this process in AMD rats. The created induced pluripotent stem cells (iPSCs) from epithelial cells and the converted these iPSCs into induced neural progenitor stem cells (iNPSCs). On injecting these iNPSCs cells into AMD rats , the AMD progression slowed by 130 days which is equivalent of 16 years in humans. This study shows the amazing promise of stem cells in treatments for AMD.
The team now aims to carry out preclinical trials on animals to test the efficiency and safety of stem cells injection before clinical trails can begin on people who are suffering from later stages of AMD.

Article summary courtesy by Waleed Khan

Article: Medical News Today

References: 
Human iPSC-derived neural progenitors preserve vision in an AMD-like model, Yuchun Tsai, et al., Stem Cells, doi:10.1002/stem.2032, published online 13 April 2015, abstract.