1. A Big Bang model of human colorectal tumor growth
a. The Authors, members of the Curtis Lab at Stanford University, propose and justify the Big Bang model for colorectal tumor growth. This model is dependent on several characteristics found in samples including the absence of selective sweeps, uniformly high intratumoral heterogeneity (ITH) and subclone mixing in distant regions. The model concludes that mutations occurring early in the tumor development will have a larger effect on overall tumor composition compared to later mutations in spite of the fitness advantages presented by either mutation. This model also provides a possible biomarker for determination of malignant vs benign phenotypes from the primordial tumor. Carcinomas were
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The authors. Primarily members of the Sherlock lab at Stanford University, constructed a sequencing-based ultra-high-resolution lineage tracking system in Saccharomyces cerevisiae to allow monitoring of several cell population lineages simultaneously. A plasmid library containing, 500,000 random barcodes was inserted into the genome at a landing pad to act as a barcode. Barcoding requires 48 generations of growth from a common ancestor before analysis. To count the relative frequency of each lineage across time, genomic information including lineage barcodes were isolated from the DNA of pooled populations using a two- step PCR protocol, and sequenced amplicons. The population dynamics observed indicated that for mutations to fixate, they must provide advantages above the mean fitness and grow at a rate quick enough so that mutation establishment is not prevented. This paper served as one of the first primary examples of genetic bar coding, including the methods of inserting genetic barcoding via a restriction enzyme/cloning/ligating mechanism. The articles findings are strong, including theoretical computational models and physical samples analyzed with barcode …show more content…
The authors, members of the Stanford department of medicine, explore the applications of using organoid cultures for cancer modeling purposes. Organoid cultures contain epithelial and mesenchymal components and provide a more accurate multi-lineage cell culture comparable to in vivo systems while also allowing in simple in vitro manipulation techniques. The organoid systems also utilized an air-liquid interface methodology which supports organoid growth as epithelial and mesenchymal hybrids without the necessity for growth factor supplementation and allows in vitro cancer modeling in a “more physiologic milieu” than what was previously possible using transformed cell lines or exclusively epithelial cultures. This has increased utility in an oncology setting due to the ability for is situ histologic observations regarding dysplasia and transformation in an organ context. These results are not found when modeled in standard cell lines, revealing new information about neoplasm growth and development without involving in vivo methods. New developments are exploring the necessities for increased large scale system observations before in vivo or medical trials, and organoid systems are allowing this in a convenient and useful
Glase, Jon C. A Study of Gene Linkage and Mapping Using Tetrad Analysis in the Fungus
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Hall, Linley Erin. “Understanding Genetics DNA and RNA.” New York: The Rosen Publishing Group, Inc., 2011. Print. 01 Apr. 2014.
I have chosen to write about the constellation Cancer (The Crab). I chose Cancer because it is one of only a handful of constellations that I am actually able to identify in the night sky. Cancer is one of the twelve Zodiac constellations; people whose birthdays fall between June 21st and July 22nd have Cancer as their sign. Cancer is the Latin word for crab, and despite the fact that the constellation looks more like a lobster then a crab, it is still referred to as a crab. The constellation is visible from the northern hemisphere from late winter to early spring.
Cancer has been an active concern in our society for the past couple decades, since we truly discovered the nature of cancer and the potency it brings along with it. However, it was not until the mid-20th century that scientists were beginning to truly understand the origin of cancer. Scientists dating back all the way to the Renaissance, when they first began performing autopsies to learn more about the human body and form, noticed abnormalities but it never clicked that it was something much worse than it seemed. Research has continued since then, and it has continued to thrive even to this day. When James Watson and Francis Crick discovered DNA and it’s chemical structure in 1962, it opened up doors that even they could not expect. With the understanding of DNA and how it affected the way we look at life, came the beginning of the understanding of mutated DNA (which is a cause of the growth of cancerous cells). In this past century, researching scientists discovered that cancer is linked with the DNA that resides in a cell’s nucleus. By ways of damage to the cells via chemicals or radiation, or even introduction of a new DNA, the cancerous cells begin to form and duplicate. We are learning more and more about cancer and how to fight it, but we still have much more to learn.
... starts relaxing the supercoils and altering of DNA and interacts with DNA helicase SGS1 and plays a role in DNA recombination, also cellular aging and maintenance of genome stability. Alternate splicing results in multiple transcript variants. Additional spliced variants of the gene have been described, but their complete length is unknown.
Colon cancer develops in the part of the gastrointestinal tract that absorbs water and minerals before waste products are disposed via the rectum. In women endometrial cancer is related to colon cancer. This type of cancer is the second leading cause of death due to cancer in the United States. Over one-hundred fifty thousand individuals will be diagnosed this year and this cancer will probably be responsible for about 47,900 deaths in 1999 (http://www.cancer.org). Most colon cancers are adenocarcinomas that develop from the glandular cells. Ninety percent of all colon cancer cases will develop in individuals after 50 years of age. Ninety percent of all tumors arise from polyps that are commonly found in people older than 50. Prevention includes regular exercise and a diet high in fiber. The most important risk factor is age. Medical screening includes a yearly blood occult test after age 50 and a colonoscopy every 3 years after age 50. Regular screening detects polyps that have become precancerous. If regular screening is not done, the cancer is not detected until blood is found in the...
According to the American Cancer Society, the third leading cause of cancer related deaths for African American men and women is colorectal cancer (CRC). African Americans have a higher CRC mortality rate than White men and women due to lack of preventative testing, increased cancer fatalism attitudes, decreased knowledge of the cancer, and late onset diagnosing. To research how to resolve this issue the “Fayetteville Area Inter-Faith Commitment to Colorectal Health and Cancer Reduction in African Americans,” or “The F.A.I.T.H Project” was created to execute a culturally targeted faith/community-based educational intervention about CRC within the African American community.
Modern techniques , rather than the gene map , maps the map of the DNA within the gene itself : the positions of short sequences " marker " are used as markers signaling over the cromosssomas . Once a gene is discovered, it is necessary to unravel its base sequence prior to its function being studied . The sequencing has become easier with the development of methods for cloning the DNA - producing large amounts of identical fragments. In the method most widely used DNA sequencing , the chain is denatured into single strands . These are then used as templates for DNA synthesis , but such that replication to as the double helix reaches a certain growth in the mold base . In addition to provide DNA polymerase and the four bases, A - G -C- T, also using small amounts of these dideoxynucleotide bases. This is incorporated , as the normal bases, the double helix growth but prevent the continuation of the chain. The fragments are then separated by gel electrophoresis and the base seq...
Colon Cancer is cancer of the colon, or large intestine. Rectal cancer is cancer of the last few inches of the colon. Together, they're often referred to as colorectal cancers. Most cases of colon cancer begin as small, harmless clumps of cells called polyps. Over time some of these abnormal growths may become colon cancers. Polyps may be small and produce few, signs of sickness. Because of this, doctors recommend regular screening tests to help prevent colon cancer.
Colorectal cancers are thought to develop slowly over a period of several years. Before a true cancer develops, there usually are precancerous changes in the lining of the colon or rectum. These changes might be dysplasia or adenomatous polyps. A polyp is a growth of tissue into the center of the colon or rectum. Some types of polyps (hyperplastic polyps and inflammatory polyps) are not precancerous. However, having adenomatous polyps, also known as adenomas, does increase a person’s risk of developing cancer, especially if there are many polyps or they are large.
Laughter is often said to reduce stress and produce pain reliving hormones. It is the ‘fountain of youth’, the secret ingredient to longevity. A person who laughs all the time is, more often than not, healthier and happier than a person who rarely laughs at all. Laughter is known as a natural form of medicine. However, like many other things, some people take the laughter and the jokes too far. This is the case in the story, “The Approximate Size of My Favorite Tumor,” by Sherman Alexie.
Cancer develops when cells in a part of the body begin to grow out of
Cancer is a disease that affects human somatic cells. It causes the cells to divide uncontrollably and form masses known as tumors. There are two different types of cancer tumors. Some tumors are benign and other tumors are malignant. Benign tumors look similar to the tissues that they came from and develop slowly. The tumor remains in the same area that the tumor originated in. Malignant tumors are formed from cells that do not resemble the tissue that they came from. They vary in shape and size. This enables pieces of the tumor to break off and spread to other places in the body. Over the past few decades cancer has become a very prominent disease. There are many different types of cancer and many different causes for the the disease. Most cancers are because of a genetic mutation. The most common type occur when a cell is dividing. Proto-oncogenes, which are alleles in a normal cells, mutate to form oncogenes. These oncogenes cause cancer because they do not allow the cells to self destruct or become epistatic. There have been several research projects which have been testing epistatis.
Histopathological samples are examined in vivo where the relationship between the cells is maintained and observable. These can be cross sections of small organs or slices of larger ones. This results in a large number of cells being available and their cell-to-cell interactions apparent for examination.