Somatostatin Receptor Based Imaging and Radionuclide Therapy

Table 2

The advantages and disadvantages of main viral vectors used to transfer hSSTr2.

Vectors	Advantages	Disadvantages	References
Adenovirus	() Stability; () High titers; () Infecting dividing and nondividing cells; () High level expression of transgene; () Not integrating into host chromosome	() Strong immune response; () Potential replication competence; () Short-term expression; () Demanding packaging cell line; () Small insert size; () No targeting	[103–105]
Adenoassociated virus	() No associated disease; () Long-term gene expression; () Integrating into human chromosome 19	() Extensive antiviral immunity; () Helper-dependent replication; () Poor host tropism; () Small insert size: about 5 kb	[106]
Retrovirus	() Integrating into host cell genome; () Reverse transcription of the RNA genome; () Infecting dividing cells; () Long-term expression; () Fairly high titers	() Immune-related toxicity; () Infecting dividing cells; () Potential replication competence; () Insertion mutation; () No targeting	[107, 108]
Vaccinia virus	() Cytolytic viral vector; () Preferentially infecting rapid dividing cells; () Difficult to leak from normal vasculature; () The vector itself serving as a therapeutic method; () Large insert size: ≥25 kb DNA	() Live infectious lytic virus; () Replication competence; () Short-term gene expression; () Postvaccinal encephalitis and progressive complications; () No targeting	[109, 110]