CANCER THERANOSTICS/ DEEP TISSUE IMAGING: Engineered virus facilitates solid tumor diagnosis and phototherapy

What does the natural imaging potential of melanin have in common with the ability of recombinant Vaccinia viruses to target and replicate within tumor cells? Perhaps nothing, until they are combined. Now, thanks to the work of scientists at Genelux Corp., these factors have enabled cancer theranostics: treatment and deep tissue imaging, as a newly published study explains.1

Melanin is a pigment produced by melanoma and other types of cancer that appears very bright in magnetic resonance imaging (MRI). Its expression by the engineered virus achieved concentrations sufficient to enable enhanced MRI and optoacoustic (a.k.a. photoacoustic) imaging, as well as thermotherapy (laser-induced thermal lysis) of melanin-producing tumors. The approach can serve as a visible marker during surgery, as a mediator of laser-induced phototherapy, and as a reporter (an easily identified and measurable gene product). This achievement results from characteristics of the Vaccinia virus, which replicates only in the cell's cytoplasm: It has large foreign-gene-carrying capacity and efficiently colonizes tumors, according to Aladar Szalay, Ph.D., senior study author and founder and CEO of Genelux.

Researchers at the company have been working to develop recombinant Vaccinia virus strains for deep tissue imaging. To facilitate melanin production, they inserted the genetic information encoding melanin-producing enzymes into the genome of strains able to infect cancer cells. MRI effectively detected the resulting melanin production and localization in both solid tumors and very small metastases. Szalay noted that the experiments enable design and production of imaging agents without needing added substrates, which currently limit the utility of imaging agents.

The team also used near-infrared (NIR) lasers to increase the temperature of the light-absorbing, melanin-producing tumor cells and tissues to >150°F, which effectively destroyed the tumors in live animals. By comparison, healthy cells allowed little light absorption and could only be heated by a few degrees; no cell death was observed.

The study also found new melanin-encoding viral strains useful for generating specific signals in multispectral optoacoustic tomography (MSOT), a novel technology for high-resolution, deep-tissue molecular imaging that generates 3D views of site(s) absorbing the greatest amount of light. MSOT signals were very intense in virus-colonized, melanin-producing tumors and metastases, allowing excellent imaging. William G. Bradley, M.D., Ph.D., FACR, chair of the Department of Radiology at the University of California, San Diego (UCSD) School of Medicine and study co-author, said that the use of melanin-producing enzymes as reporters will likely have a significant impact on basic research, and also possibly aid medical applications, beginning with clinical trials for cancer. "One day we may see laser-mediated thermal ablation of melanin-producing tissues when surgical removal is not an option," he said.

1. J. Stritzker et al., Proc. Nat. Acad. Sci., 110, 9, 3316–3320 (2013).

Get All the BioOptics World News Delivered to Your Inbox

Subscribe to BioOptics World Magazine or email newsletter today at no cost and receive the latest news and information.

 Subscribe Now
Related Articles

New bioimaging technique offers clear view of nervous system

Scientists at Ludwig-Maximilians University have developed a technique for turning the body of a deceased rodent entirely transparent, revealing the central nervous system in unprecedented clarity....

Fluorescent jellyfish proteins light up unconventional laser

Safer lasers to map your cells could soon be in the offing -- all thanks to the humble jellyfish. Conventional lasers, like the pointer you might use to entertain your cat, produce light by emittin...

Microscope detects one million-plus biomarkers for sepsis in 30 minutes

A microscope has the potential to simultaneously detect more than one million biomarkers for sepsis at the point of care.

Eye test that pairs two in vivo imaging methods may detect Parkinson's earlier

A low-cost, noninvasive eye test pairs two in vivo imaging methods to help detect Parkinson's before clinical symptoms appear.

BLOGS

Neuro15 exhibitors meet exacting demands: Part 2

Increasingly, neuroscientists are working with researchers in disciplines such as chemistry and p...

Why be free?

A successful career contributed to keeping OpticalRayTracer—an optical design software program—fr...

LASER Munich 2015 is bio-bent

LASER World of Photonics 2015 included the European Conferences on Biomedical Optics among its si...

White Papers

Understanding Optical Filters

Optical filters can be used to attenuate or enhance an image, transmit or reflect specific wavele...

How can I find the right digital camera for my microscopy application?

Nowadays, image processing is found in a wide range of optical microscopy applications. Examples ...

CONNECT WITH US

            

Twitter- BioOptics World