were also inoculated into nude mice with only the 7078T cells forming tumors. 
Therefore, the morphology and ability to grow in low serum, as well as, anchorage 
independent growth and tumor formation in nude mice indicates that the 7078T cell 
line was transformed. 
We next performed Southern blot analysis and showed that the pG2N retroviral 
vector was present in the C2, 7078, and 7078T cell lines (figure 32). The clonality of 
C2 and 7078 can also be demonstrated by Bgl II restriction enzyme digests, an 
enzyme that digests within the retroviral vector, by the presence of a single identical 
band in the C2 and 7078 cell lines. Finally, we can show not only the rearrangement 
of the growth hormone gene in the 7078T cells but also the rearrangement the c-myc 
oncogene (figure 33). Since the G2N retroviral vector did not insert near the c-myc 
oncogene, it may be possible that the G2N vector produces a trans activating factor 
which effected the c-myc oncogene. This represent the first reported association of a 
retroviral vector and a transformed cell. 
33 
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