New Technology Assists Scientists In The Study Of Early Cancer

November 05, 1996

For years, doctors have looked at tissue biopsies and spotted unusual cells that seem to have early signs of cancer. The problem is doctors have never had the right tools to extract the cells from the tissue, leaving them with no good way to confirm their observation while the tumor is in its early stages and most treatable.

That is until now. In this week's issue of the journal Science,1 a team of researchers at the National Institutes of Health (NIH) report on a powerful new technique, called laser capture microdissection, that can pull out a small cluster of cells from a tissue sample in as little as eight seconds.

By taking these cells directly from the tissue, the scientists say they can immediately analyze the cells' gene and enzyme activity with other research tools. Currently, scientists must attempt to extract, or microdissect, cells either by trying to yank them free with a manual tool or through a convoluted process of isolating and culturing the cells. Most scientists say they consider both approaches to be tedious, time-consuming, and inefficient.

According to Lance Liotta, M.D., Ph.D., a scientist at the National Cancer Institute (NCI) and senior author of the paper, the direct access to cells should lead to a revolution in the understanding of the molecular basis of cancer and other diseases, helping to lay the groundwork for earlier and more precise disease detection.

"Having this technique is the difference between being able to investigate a crime in progress and going back two weeks later to the scene of the crime when much of the evidence has vanished, as we typically do now," said Liotta. "Laser capture microdissection gives us access to the disease, in a sense, while the crime is still in the planning stages, and that's really powerful information to have in designing strategies to halt the disease process."

Laser capture microdissection is a fully automated, one-step technique that, in today's high-tech world, has emerged as a remarkably low-tech creation. It integrates a standard laboratory microscope with a low-energy laser and a transparent ethylene vinyl acetate polymer thermoplastic film--the same plastic seal in a container of yogurt.

Mike Emmert-Buck, M.D., Ph.D., an NCI scientist and lead author of the paper, said the group's prototype device works on the same basic aim-and-shoot principle as an instamatic camera:

€ Scientist looks through a microscope at a tissue biopsy, which typically contains hundreds of different types of cells.

€ Upon spotting a group of tumor cells, for example, the scientist presses a button attached to the side of the microscope. The button activates the laser, which flashes a beam of light that has an intensity slightly greater than a laser pointer.

€ The beam of light passes through the plastic film placed above the tissue sample and focuses onto the cells. In the process, the beam heats the plastic, giving it the thermal qualities of a piece of scotch tape. The cells then stick to the plastic directly above them, whereupon the cells are immediately extracted and ready for analysis.

Emmert-Buck said he and his colleagues purposely designed their device with a camera in mind. "We wanted an instrument that any scientist could sit down and use immediately," he said. "That meant creating a fully automated, user- friendly device that was free of any tricky, manual manipulations to complicate its operation. A camera seemed like a device that is simple and familiar to most people. With this idea in mind, we spent about two years creating a viable, one-step technique."

In the Science paper, Emmert-Buck and his colleagues report that laser capture microdissection has successfully extracted cells in all tissues in which it has been tested. These include kidney glomeruli, in situ breast carcinoma, atypical ductal hyperplasia of the breast, prostatic interepithielial neoplasia, and lymphoid follicles.

They reported no limitations in their ability to amplify DNA or RNA from tumor cells extracted with laser capture microdissection. The scientists also found they were able to recover enzymes from within the cells and test them for activity.

Robert F. Bonner, Ph.D., a co-author on the paper and a scientist with NIH's National Center for Research Resources, said laser capture microdissection, like all emerging techniques, still has room for improvement. Bonner said with further refinement of the plastic film and activation of a finer laser beam, he could easily foresee the technique extracting single cells, rather than the two or three cells at a time that it now yields.

Another likely role for the technique is in helping to record the patterns of gene expression in various cell types, an emerging issue in medical research. For instance, NCI's Cancer Genome Anatomy Project (CGAP) seeks, in part, to define the patterns of gene expression in normal, pre-cancerous, and malignant cells.

In projects such as CGAP, laser capture microdissection fits in nicely at the front end of the process as the tool that procures pure cell samples from tissue, feeding the rest of the analytical process.

Given the technique's great potential to forward the study of biology and medicine, the NCI has made plans to make the device widely available to researchers and clinicians around the country. A demonstration project is already in the works with Steven Bova, M.D., a scientist in the Departments of Urology and Pathology at The Johns Hopkins University School of Medicine. Liotta said the aim of this project is to receive input from fellow researchers on how the device might be simplified even more, while also achieving the highest standard of quality.

"As new information accrues about the genetics of cancer and other human diseases, it opens up new opportunities for discovery, which will ultimately lead to more targeted ways to diagnose and treat disease," said Richard Klausner, M.D., NCI director. "The NCI recognizes that it has a commitment to place powerful, new research tools into the hands of scientists to catalyze the discovery process. And, the NCI will make every effort to do so with laser capture microdissection."
-end-

The Cancer Information Service provides a nationwide telephone service for cancer patients and their families, the public, and health care professionals. The toll-free number is 1-800-4-CANCER (1-800-422-6237); services provided in English and Spanish. People with TTY equipment may call 1-800-332-8615.

This document is available through the NCI's CancerNet services on the Web (http://cancernet.nci.nih.gov) and through Cancer Fax (dial 301-402-5874 from the handset on your fax machine).

NIH/National Cancer Institute

Related Cancer Articles from Brightsurf:

New blood cancer treatment works by selectively interfering with cancer cell signalling
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.

UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.

Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.

Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.

Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.

Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.

More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.

New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.

American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.

Read More: Cancer News and Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.