Retroviral vector design for gene therapy of cancer: specific inhibition and tagging of BCR-ABLp190 cells.
BACKGROUND
The main difficulty in providing effective treatment of patients with cancer is distinguishing between tumor and normal cells. The chimeric molecules created by cancer-associated chromosomal abnormalities (such as the BCR-ABL fusion protein) represent ideal therapeutic targets since they are unique to the disease state. A major challenge, however, is how to deliver the specific anti-tumor agent into every tumor cell.


METHODS
In this report we describe the use of a novel strategy to introduce specific anti-tumor reagents into every tumor cell. It uses retroviral vectors encoding both antisense transcripts specific for the BCR-ABLp190 fusion junction (the specific anti-tumor drug) and a truncated human CD5 cDNA, which allows selection of the infected cells. In order to coexpress the antisense molecule with the truncated human CD5 gene, the picornavirus internal ribosome-entry site was incorporated in the constructs.


RESULTS
When the antisense transcripts in the CD5-retroviral vector were introduced into Ba/F3+p190 cells rendered interleukin 3 (IL-3) independent by expression of the BCR-ABL sequences, the cells died upon IL-3 withdrawal, as measured by the absence of CD5-positive cells. Control Ba/F3+p210 cells infected with the same virus did not die in the absence of IL-3.


CONCLUSIONS
These data suggest a novel strategy for cancer treatment which incorporates the use of a retrovirus coexpressing both a selectable surface marker and a tumor-specific agent.
García-Hernández
B
B
Departamento de Proliferación y Diferenciación Celular, Instituto de Microbiología Bioquímica, Salamanca, Spain.
Sánchez-García
I
I
D000970:Antineoplastic Agents / Q000494:pharmacology; D001483:Base Sequence; D018956:CD5 Antigens / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D002460:Cell Line; D005434:Flow Cytometry; D016044:Fusion Proteins, bcr-abl / Q000737:chemistry / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000737:chemistry / Q000235:genetics; D006801:Humans; D007377:Interleukin-3 / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009369:Neoplasms / Q000628:therapy*; D016372:RNA, Antisense / Q000235:genetics / Q000494:pharmacology; D012333:RNA, Messenger / Q000037:antagonists & inhibitors; D012190:Retroviridae / Q000737:chemistry / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics
D000970:Antineoplastic Agents; D018956:CD5 Antigens; D005819:Genetic Markers; D007377:Interleukin-3; D008562:Membrane Glycoproteins; D016372:RNA, Antisense; D012333:RNA, Messenger; D016044:Fusion Proteins, bcr-abl