Abelson murine leukemia virus variants with increased oncogenic potential

Area of Science:

• Virology
• Molecular Biology
• Oncology

Background:

• Abelson murine leukemia virus (A-MuLV) strains exhibit varying cell transformation efficiencies.
• A-MuLV-P90, a mutant of A-MuLV-P120, encodes a truncated protein and efficiently transforms NIH 3T3 cells but poorly transforms lymphoid cells.

Purpose of the Study:

• To investigate the role of the carboxy-terminal region of the A-MuLV protein in cell transformation and tumor induction.
• To characterize A-MuLV variants that arise from A-MuLV-P90 infection and their impact on lymphoid cell interaction.

Main Methods:

• Analysis of A-MuLV variant viruses derived from tumors induced by A-MuLV-P90.
• In vitro transformation assays using NIH 3T3 and lymphoid cells.
• In vivo tumor induction studies in mice.

Main Results:

• Tumors induced by A-MuLV-P90 frequently contained variant viruses with altered A-MuLV protein sizes.
• Variants with larger proteins resembled A-MuLV-P120 in transformation.
• Variants with smaller proteins induced tumors rapidly in vivo but failed to efficiently transform lymphoid cells in vitro.

Conclusions:

• Sequences in the carboxy-terminal region of the A-MuLV protein are critical for interaction with hematopoietic cells.
• The ability to transform lymphoid cells in vitro can be separated from the capacity for in vivo tumor induction.
• A-MuLV variant evolution provides insights into viral oncogenesis and host cell tropism.