Previous Human Experience with Gene therapy in Cancer The ability to 
manipulate and insert genes into human cells has opened new possibilities for treating cancer (39). 
Initial human trials involved tumor infiltrating lymphocytes (TIL) harvested from resected tumors. 
Marker genes were added to the TIL to demonstrate the feasibility and safety of using retroviral- 
mediated transduction of human cells (40). TIL marked with a gene for neomycin resistance were 
returned to cancer patients and demonstrated to accumulate at tumor sites. The IL-2 dependence of the 
retroviral-transduced TIL is believed to provide a safeguard against transformation to a malignant 
phenotype (41). In other studies, TIL have been transfected with the Tumor Necrosis Factor (TNF) gene. 
When activated, widespread tumor necrosis occurred and remission of disease was reported (41). Viral 
vectors have certain advantages over physical and chemical methods for introducing DNA into human 
cells. First a wide range of cell types can be infected. Second the efficiency of the process approaches 
100%. However, use of retroviruses in clinical trials continues to raise concerns about safety. One fear 
has been that recombination of vector sequences with coding sequences in the infected cell line could 
generate replication-competent viruses. Modifications to the viral genome would minimize this 
possible risk (42). 
A retroviral or herpes simplex vector that replicates only in dividing cells has 
provided the rationale for two new gene therapy approaches to glioma. An experimental therapy of 
human glioma using a genetically engineered herpes simplex virus-1 (d/sptk), attenuated for 
neurovirulence has been tested in nude mice. In vitro, the vector destroyed a human glioma line (U87) 
when added over a wide range of concentrations. In vivo, the injection of the d/sptk vector into U87 
gliomas in nude mice resulted in improved survival, and total tumor remission in some animals (43). 
Another approach has used mouse fibroblasts genetically altered with a retroviral vector carrying a 
herpes gene for thymidine kinase(HS-tk). The fibroblasts were injected stereotactically into C6 
gliomas of rats. After 5 days during which the replicating HS-tk retroviral vectors transduced 
neighboring proliferating glioma cells, the rats were treated with the anti-herpes drug ganciclovir 
(44). The gliomas underwent complete macroscopic and microscopic regression. This protocol is currently 
in human trials (45). 
C. Study Design 
1. Specific Procedures 
-Overview of Experimental Treatment Plan 
a . Informed consent will be obtained after surgical intervention in patients 
and histologic confirmation of glioblastoma multiforme. 
b. Tumor cells will be obtained at the time of stereotactic brain biopsy for 
diagnosis, or at the time of open craniotomy for therapy. 
c. Cell cultures will be established irrespective of final histology. 
d. The expression of IGF-I by the cultured cells will be determined by an 
ELISA technique. 
e. Cultured cells from those tumors which have histopathologic features 
of glioblastoma multiforme and which demonstrate IGF-I production 
will be transfected with the episome- based vector containing antisense 
to IGF-I. 
f. Transfected cells will be irradiated with 5,000 cGy and injected 
subcutaneously into the patient from which they were obtained. 
g. Dose calibration. Three groups of four patients each will be treated 
subcutaneously at each of the f ciiowing doses of transfected and 
irradiated cells: 10X10 6 , 50X10 6 , and 200X10 6 . 
h. Booster injections of transfected and irradiated cells will be introduced 
at 4 and 12 weeks. 
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