Another piece of cancer puzzle falls into place

first_imgAn international team of researchers has created a genome-scale map of 26 cancers, revealing more than 100 genomic sites where DNA from tumors is either missing or abnormally duplicated compared to normal tissues. The study, the largest of its kind, finds that most of these genetic abnormalities are not unique to one form of cancer, but are shared across multiple cancers.“Our findings show that many genome alterations are universal across different cancers. Although this has been known for some types of changes, the degree to which so many alterations are shared was pretty surprising to us,” said senior author Matthew Meyerson, a Harvard Medical School professor of pathology at the Dana-Farber Cancer Institute and senior associate member of the Broad Institute of Harvard and MIT. “It suggests that, in the future, a driving force behind cancer treatment will be common genomic alterations, rather than tumors’ tissue of origin.” The work appears in yesterday’s edition of the journal Nature.Cancers now are characterized largely by their symptoms: the organs in the body in which they first arise and the appearance of tumor cells under a microscope. Although this information is valuable, it fails to highlight cancers’ molecular underpinnings, which could be used in laboratories to discover new, more effective cancer therapies and in the clinic to improve diagnosis and treatment. A goal ofmodern biomedical research is to fill this knowledge gap and describe all cancers based on what drives them — that is, the genetic aberrations that initiate and maintain tumor growth.In 2004, a scientific team led by researchers at the Dana-Farber and the Broad Institute launched a project to map systematically the genetic changes across different cancers. They focused on a particular type of DNA change in which segments of a tumor’s genome are present in abnormal copies. Instead of the usual two copies, tumors often carry several copies of one piece of DNA (an “amplification”) or may lack it altogether (a “deletion”). These genetic abnormalities are known as somatic copy-number alterations, or SCNAs.Like other types of DNA mutations that litter the genomes of tumor cells, most SCNAs do not necessarily play a meaningful role in cancer growth. But the ones that do serve as important signposts, pointing to the specific genes contained within them that help to promote and maintain cancers. The challenge lies in distinguishing these so-called drivers from their less influential counterparts.As the foundation for their analysis, the scientists collected more than 2,500 cancer specimens representing more than two dozen cancer types, including lung, prostate, breast, ovarian, colon, esophageal, liver, brain, and blood cancers.“Studies like this require a large and diverse group of tumor specimens,” said first author Rameen Beroukhim, an assistant professor of medical oncology at Dana-Farber Cancer Institute and a researcher at the Broad Institute. “We are deeply grateful to our collaborators and to their patients, who generously shared samples with us.”Using powerful genomic “chip” technologies, the researchers analyzed DNA from these samples, and combined their data with publicly available data from 600 more tumor samples to assemble a detailed catalogue of the SCNAs present in multiple tumor types. They found that the most common SCNAs tend to come in two sizes: relatively long, about the length of an entire chromosome or a single chromosome arm, and short, with an average size of about 1.8 million genetic letters, or 0.03 percent of the entire human genome.The researchers focused their attention on the short, or focal, SCNAs which, due to their relatively compact size, can ease the task of pinpointing important cancer genes.“Until recently, the analytic methods needed to support this kind of analysis were not available,” said first author Craig Mermel, a physician and Ph.D. student working in Meyerson’s laboratory and at the Broad Institute. “New advances by our group as well as many others have now made it feasible to systematically map genomic changes across thousands of samples and at high resolution.”Of the 150 or so focal SCNAs they identified, Meyerson and his colleagues noticed that the majority did not coincide with genes already known to be amplified or deleted in cancer. Looking more closely at the genes that normally reside in these regions, the researchers found an enrichment of genes with important biological functions in cancer, such as cell death, or “apoptosis.”This analysis helped to shed light on two genes, MCL1 and BCL2L1. Cancer cells with amplifications of these genes appear to rely on the genes’ activity for survival, suggesting important roles in maintaining tumor growth.Perhaps most importantly, looking across the data for the various cancers, it became clear that most focal SCNAs are not unique to just one type of cancer, but are shared among multiple tumor types. In an analysis of 17 cancer types, the researchers found that most amplifications and deletions are present in more than one type. That suggests the genetic mechanisms that underlie these tumors are shared among them, and could someday lead to common strategies for treating them.“These data signify an important resource for cancer gene discovery, but they’re only a first step,” said Meyerson. “With the ongoing revolution in genome technology, it will become possible to decode the genomes of thousands of cancers to reveal every genomic change.”The Nature study was supported by the National Institutes of Health, the Doris Duke Charitable Foundation, the Sarah Thomas Monopoli Lung Cancer Research Fund, the Seaman Corporation Fund for Lung Cancer Research, and the Lucas Foundation.last_img read more

Read More →

D’Tigers Condemned to Beat Korea for Second Round Ticket

first_img*Stumble again against Argentina after initial loss to RussiaDuro IkhazuagbeAfter D’Tigers lost their second straight game of the ongoing FIBA World Cup in China to Argentina 81-94 points yesterday, Nigeria’s hope of qualifying for next year’s Olympic Games in Tokyo, Japan now rests squarely on the country’s senior men’s team defeating Korea in their third match of the series. Nigeria lost her first game to Russia last Saturday. Another loss would mean Nigeria automatically handing over the continent’s ticket to Tunisia who defeated Iran 79-67 yesterday.Despite a spirited effort from the young side paraded by Alex Nwora and ending the first half 43-43 apiece against the South Americans who are the fifth rated team in the world, it was not enough to see D’Tigers pocket their first victory.The Nigerian lads could only manage to win only the second quarter of the game 17-28, 26-15, 18-29, 20-22.Josh Okogie who on Sunday celebrated his 21st birthday, again was the top performer for the team with 18 points, five assists and two rebounds.Jordan Nwora scored 12 points, two assists and caught three rebounds during the 20.51minutes he spent on the court.Al-Farouk Aminu put in a good shift defensively for the team with eight rebounds and three points.Despite the narrow loss, Head Coach of the Nigerian team, Alex Nwora said he was proud of the team and that D’Tigers lost to a better side despite battling hard to grind out a win.Nwora said that it was not the result the boys wanted but that in basketball, losing and winning were all part of the game.“I am proud of them. We battled for our lives, we battled back for a better deficit unfortunately, we fell short in some areas.”Nwora said the D’Tigers team is a young team and have not played together for a long time compared to most teams competing at the World Cup.“This particular team is a very young team. Some of the players are playing together for the first time. I believe if we continue blending this team, we can only get better if we keep this team together.”He said attention will now be focused on the last group game against Korea as the search continues for the win.The Tunisians who lost their opening game to Spain have won a game and if they win a second against Puerto Rico and move into the second round, Nigeria will be out of contention for the Olympic ticketIf they lose their third game and D’Tigers win against Korea, points scored between the two teams will play a role in deciding who gets the ticket.NBBF Board Member, Col. Sam Ahmedu (rtd) told THISDAY last night that hope was not lost yet.“If Puerto Rico beats Tunisia and we beat Korea, the points scored and conceded will be added to decide who is better placed between Nigeria and Tunisia. Don’t forget the Tunisians lost to Spain by a wide margin,” observed the NBBF board member last night from China.There is only one ticket for African to the Olympics, same goes for Asia and Oceania while Europe and the Americas have two teams each.Share this:FacebookRedditTwitterPrintPinterestEmailWhatsAppSkypeLinkedInTumblrPocketTelegramlast_img read more

Read More →