Features | Partner Sites | Information | LinkXpress
Sign In
AB Sciex
SEEGENE
FOCUS DIAGNOSTICS, INC.

Blood Test Locates Gene Defects Linked to Cancer

By Labmedica International staff writers
Posted on 21 Jan 2014
Image: The Nanodrop 1000 Spectrophotometer (Photo courtesy of Thermo Fisher Scientific).
Image: The Nanodrop 1000 Spectrophotometer (Photo courtesy of Thermo Fisher Scientific).
A simple blood test could be developed to determine whether gene mutations associated with pancreatic cancer exist without the need of locating and testing tumor tissue.

This blood test appears possible following the discovery that tiny particles called exosomes, which are shed by cancer cells into the blood, contain the entire genetic blueprint of cancer cells and by decoding this genomic data and looking for deletions and mutations associated with cancer; these findings could be translated into a test that helps physicians detect cancer.

Scientists at The University of Texas MD Anderson Cancer Center (Houston, TX, USA) collected serum samples on the day of surgery from patients undergoing surgical resection of their tumors. The team investigated whether exosomes from pancreatic cancer cells and serum from patients with pancreatic ductal adenocarcinoma contain genomic DNA.

Exosomes were isolated from the serum samples and cell cultures. DNA was extracted and other techniques such as flow cytometry analysis, western blots were performed. The amount of DNA from cells and cell-derived exosomes was quantified using a Nanodrop 1000 Spectrophotometer (Thermo Fisher Scientific; Wilmington, DE, USA). Whole genome sequencing was performed using the ThruPLEX-FD library prep technology (Rubicon Genomics; Ann Arbor, MI, USA) in combination with the HiSeq2000 sequencing platform (Illumina; San Diego, CA, USA).

The scientists found evidence that exosomes contain greater than 10 kilobase (kb) fragments of double-stranded genomic DNA. Mutations in the V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) and the tumor protein p53 can be detected using genomic DNA from exosomes derived from pancreatic cancer cell lines and serum from patients with pancreatic cancer. In addition, using whole genome sequencing, they demonstrate that serum exosomes from patients with pancreatic cancer contain genomic DNA spanning all chromosomes. These results indicate that serum derived exosomes can be used to determine genomic DNA mutations for cancer prediction, treatment, and therapy resistance.

Raghu Kalluri, MD, PhD, the senior author of the study, said, “At the present time, there is no single blood test that can screen for all cancer related DNA defects. In many cases, current protocols require a tumor sample to determine whether gene mutations and deletions exist and therefore determine whether the tumor itself is cancerous or benign. To procure tumor tissue, one needs to know that a tumor exists, and if so, is it accessible for sample collection or removal? Finally, there are always risks and significant costs associated with surgical procedures to acquire tumor tissue.” The study was published on January 7, 2014, in the Journal of Biological Chemistry.

Related Links:

The University of Texas MD Anderson Cancer Center
Thermo Fisher Scientific 
Rubicon Genomics



PURITAN MEDICAL
GREINER-BIO-ONE
ADVANCED INSTRUMENTS
BioConferenceLive

Channels

Clinical Chemistry

view channel
Image: The ICON 25 hCG point-of-care pregnancy test (Photo courtesy of Beckman Coulter).

Pregnancy Tests Evaluated During Early Gravidity

The predominant hormone human chorionic gonadotropin (hCG) variant in urine, hCG β core fragment (hCGβcf), has been demonstrated to cause false-negative results in qualitative point-of-care (POC) hCG devices.... Read more

Hematology

view channel

Blood Donations Screened for Viruses Using Multiplex Assay

A global healthcare company was chosen to partner the Japanese Red Cross (JRC; Tokyo, Japan) for nucleic acid screening of the nation's blood supply. Under the terms of the 7-year agreement, the healthcare company, Grifols (Barcelona, Spain) will provide the JRC with its newest automation platform, the Procleix Panther... Read more

Pathology

view channel
Image: Immunostaining of human lung tissue, fixed with HOPE, from a patients suffering from legionnaire\'s disease. One legionella protein (red-brown), the bacteria-containing vacuoles and individual legionella inside the scavenger cells can be detected. The infection process can be observed immediately using proteomics (Photo courtesy of Braunschweig University of Technology).

Novel Method Prepares Tissue Samples for Analyzing Proteins

A new way of preparing patient tissue for analyses might soon become the new standard, possibly replacing tissues fixed with formalin, before they are embedded in wax-like paraffin and cut into razor-thin slices.... Read more

Industry News

view channel

Roche and Hitachi Renew Alliance in Diagnostics

Roche (Basel, Switzerland) and Hitachi (Tokyo, Japan) have renewed their alliance in the diagnostics business by 10-years for the joint development and manufacture of the next generation of instruments and workflow automation solutions for medical laboratories. The renewed alliance marks a significant milestone towards... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.