G protein beta 2 subunit antisense oligonucleotides inhibit cell proliferation and disorganize microtubule and mitotic spindle organization

The association of G protein beta2 subunit (G beta2) with mitotic spindles in various mammalian cells has been demonstrated previously. Recently, we h ave identified the association of G beta2 protein with microtubules (Wu et al., [1998] J. Cell. Biochem. 70: 552-562). In the present experiment we ha ve demonstrated the possible functional role of G beta2 in microtubule and mitotic spindle organization in mammalian cells. When G beta2 antisense pho sphorothioate oligonucleotides were transfected into mammalian cells, inhib ition of cell proliferation with cell death after a 4-day treatment was obs erved. If the transfected cells were incubated for two days and their G bet a2 and microtubules were examined by Western blotting and immunofluorescenc e localization, marked reduction of the G beta2 protein, fragmentation and disassembly of cytoplasmic microtubules, and disorganized mitotic spindles were found. We conclude that the G beta2 protein is closely associated with microtubule assembly and may play a potential role in the regulation of ce ll proliferation and microtubule and mitotic spindle organization in mammal ian cells. J. Cell. Biochem. 83: 136-146, 2001. (C) 2001 Wiley-Liss, Inc.