Navigation Links
UCLA researchers develop system that finds prostate cancer spread earlier than conventional imaging
Date:9/22/2011

Researchers at UCLA's Jonsson Comprehensive Cancer Center have developed a way to image the spread of a particularly dangerous form of prostate cancer earlier than conventional imaging in use today, which may allow oncologists to find and treat these metastases more quickly and give patients a better chance at survival.

The gene-based imaging system targets prostate cancers that have become resistant to androgen deprivation therapy, an aggressive form of the disease known as castration resistant prostate cancer. Once the hormone treatment is no longer working, the cancer will progress within 12 to 18 months and prognosis becomes grim, said Lily Wu, a professor of molecular and medical pharmacology, a Jonsson Cancer Center researcher and senior author of the study.

"Anytime you can detect cancer earlier, the chances of more effective control of the cancer increase and the outcomes for patients are better," Wu said. "Unfortunately, there is little that can be done to treat castration resistant prostate cancer once it has spread. In our study, we focused on finding ways to image these advanced metastatic prostate cancers accurately. "

The study appeared Sept. 21 in the early online edition of Cancer Research, a peer-reviewed journal of the American Association for Cancer Research.

Wu's team focused on using "control switches" of genes that are active only in castration resistant prostate cancer, and linked these molecular switches to a "reporter" gene that can be easily imaged. The specific switch the team used in this study is the prostate specific enhancing sequence (PSES), an androgen-independent promoter in castration resistant prostate cancer that is more specific to that form of malignancy.

The PSES is derived from the prostate specific antigen and the prostate specific membrane antigen (PMSA) and is given a boost by the two-step transcriptional amplification system, which drives the expression of the imaging reporter genes, which glow under bioluminescent or positron emission tomography (PET) scanning. The system works well in the androgen depleted environment and is strongly specific to the prostate, two conditions that are most fitting for castration resistant prostate cancer.

"The engineered system exhibits greatly elevated transcriptional activity, androgen-independency and strong prostate cancer specificity, verified in cell culture and pre-clinical mouse models," said Ziyue Karen Jiang, a senior doctoral student in pharmacology who is supported by a Jonsson Cancer Center fellowship. "These advantageous features of the system elicit superior gene expression capability for castration resistant prostate cancer in comparison to the other systems, which are driven by androgen-dependent promoters."

Based on the favorable features shown in cell culture experiments, the research team expected the PSES-driven imaging system to be discriminating in detecting castration resistant prostate cancer and cancer that has spread to distant organs. The research team was surprised to discover that the PSES imaging system developed was able to accurately detect bony metastasis of prostate cancer that grew in the leg of a mouse while two traditional imaging methods were unable to detect the metastasis.

The researchers tested the performance capacity of the PSES bioluminescent imaging system in mice that had prostate tumor cells implanted in their right knee to establish bony metastasis. After allowing six weeks for the tumor to grow, the PSES imaging reporter vector was injected into the tumor-implanted mice to search for the metastasis. Four days after the injection, the signal from the reporter gene could be clearly seen, correctly identifying the prostate cancer metastasis in the right tibia bone in nine out of nine animals. Concurrent use of PET scans were unable to distinguish between the tumor-bearing right knee and the uninvolved left knee.

The tumor growth rate in this bone metastasis model is not uniform, ranging from no spread to large tumor lesions in the bone marrow cavity. The PSES imaging system correctly identified two out of nine animals in which the tumor did not grow. These results give researchers confidence that the PSES imaging system is functioning correctly in being able to seek out prostate cancer bone metastases in a specific and sensitive manner, Wu said.

"Taken together, this study demonstrated that the promising utility of a potent, androgen-independent and prostate cancer-specific expression system in directing gene-based molecular imaging in castration resistant prostate cancer, even in the context of androgen deprivation therapy," the study states.

Prostate cancer is the most common cancer for males in America and its spread to other organs is the major cause of mortality. This year alone, more than 217,000 American men will be diagnosed with the malignancy. Of those, more than 32,000 will die from their disease.


'/>"/>

Contact: Kim Irwin
kirwin@mednet.ucla.edu
310-206-2805
University of California - Los Angeles Health Sciences
Source:Eurekalert

Related biology news :

1. Joslin researchers identify pathways leading to activation of good fat
2. Kansas researchers find enriched infant formulas benefit brain and heart
3. Researchers sequence dark matter of life
4. Researchers discover a switch that controls stem cell pluripotency
5. MU researchers unveil new method for detecting lung cancer in Nature article
6. Notre Dame researchers demonstrate antibiotic sensing event central to MSRA antibiotic resistance
7. Researchers uncover a potential new benefit of pure maple syrup on liver health
8. EPA grants help Wayne State researchers stave off Great Lakes environmental invaders
9. UTHealth, BCM researchers find common gene variant associated with aortic dissection
10. Researchers find high levels of toxic PCBs in Indiana Harbor and Ship Canal
11. UH researchers work to develop screening method for superbug
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/5/2017)... 2017 KEY FINDINGS The global ... a CAGR of 25.76% during the forecast period of ... factor for the growth of the stem cell market. ... MARKET INSIGHTS The global stem cell market is ... geography. The stem cell market of the product is ...
(Date:4/3/2017)... 3, 2017  Data captured by IsoCode, ... detected a statistically significant association between the ... treatment and objective response of cancer patients ... predict whether cancer patients will respond to ... well as to improve both pre-infusion potency testing ...
(Date:3/30/2017)... The research team of The Hong Kong Polytechnic University ... adopting ground breaking 3D fingerprint minutiae recovery and matching technology, pushing ... for use in identification, crime investigation, immigration control, security of access ... ... A research team led by Dr Ajay ...
Breaking Biology News(10 mins):
(Date:6/26/2017)... (PRWEB) , ... June 26, 2017 , ... Third Wave ... role of Sales Director, focused on leading new business development and ensuring quality customer ... of experience in the food ingredient industry in technical, marketing and sales roles. “Brett’s ...
(Date:6/23/2017)... (PRWEB) , ... June 23, 2017 , ... Ken Hanson, ... president of Physik Instrumente USA, have been selected as this year’s recipients of two ... The two have been invited along with other honorees to accept their awards at ...
(Date:6/22/2017)... ... June 21, 2017 , ... Building on the success of the inaugural RAADfest ... the very latest developments in radical life extension. RAADfest combines cutting edge science presented ... empowerment of personal development, making it the largest most comprehensive and inclusive super longevity ...
(Date:6/22/2017)... Linda, Ca (PRWEB) , ... June 22, 2017 , ... ... worldwide. It took 20 years until the first data on cross-contamination of human cell ... lines has been an increasing issue in cell culture labs and is associated with ...
Breaking Biology Technology: