Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cavitation nucleation agents (CNA) can greatly enhance DNA transfer and cell killing for therapeutically useful applications of nonthermal bioeffects of ultrasound (US). Renal carcinoma (RENCA) tumor cells were implanted and grown to about 400 microL tumor volumes on the hind legs of syngeneic Balb/c mice. Before treatment, mice were anesthetized, the tumor region was shaved and depilated, and a DNA plasmid coding for marker proteins was injected into the tumor. Two sets of tests were completed: the first set involved measurement of tumor growth for 4 days and use of a beta-galactosidase marker plasmid for localization of transfection, and the second set involved 2 days of growth and use of a luciferase marker plasmid for assessing overall protein expression. Either saline, Optison US contrast agent, a vaporizing perfluoropentane droplet suspension (SDS) or air bubble was also injected intratumorally at 10% of tumor volume as a CNA. In some tests, droplets or contrast agent were injected IV. Shock waves (SW) were generated from a spark-gap lithotripter at 7.4 MPa peak negative pressure amplitude. For sham exposure, tumor volume increased by a factor of 3.6 in 4 days. With 500-SW treatment, all the CNA reduced 4-day tumor growth about the same amount (to factors of 1.2 to 1.9). Marker gene expression was generally localized to the region around the needle injection path. All the agents, except saline, produced statistically significant increases of 11.8- to 14.6-fold in luciferase expression after 2 days, relative to sham exposure. IV injection of Optison or droplet nucleation agents before SW treatment reduced tumor growth to factors of 1.0 and 0.7, but did not increase transfection. These results demonstrate the efficacy of CNA in vivo and should lead to improved strategies for simultaneous SW tumor ablation and cancer gene therapy.
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PMID:Lithotripter shock waves with cavitation nucleation agents produce tumor growth reduction and gene transfer in vivo. 1246 61

The potential application of high-intensity focused ultrasound (US), HIFU, was investigated for nonthermal gene transfer and tumor ablation. Renal carcinoma (RENCA) tumors were implanted on the hind leg of BALB/c mice and injected with a marker plasmid. Optison US contrast agent was also injected into the tumor (IT) or into the venous (IV) circulation. HIFU at 1.55 MHz was applied to the tumors with guidance from diagnostic US images. One test of transfection was also performed with lithotripter shock waves. In one set of exposures, tumor volume was followed for 4 days and a beta-galactosidase marker plasmid was used for localization of transfected cells. A second set of exposures employed a luciferase marker plasmid for assessing overall transfection after 2 days. Use of 100-ms bursts at 8-MPa peak rarefactional pressure amplitude stopped tumor growth during the 4-day period, compared to a 2.8-fold growth in shams and yielded luciferase expression 34-fold greater than in shams. Longer bursts or higher pressure amplitudes led to decreases in tumor growth, but did not yield increases in transfection. The HIFU results were similar to those of shock waves for cavitation enhanced by IT Optison. These results should aid in optimizing the application of HIFU for nonthermal tumor treatment.
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PMID:Tumor growth reduction and DNA transfer by cavitation-enhanced high-intensity focused ultrasound in vivo. 1283 4