IQGAP1 expression was higher in primary HCC (122/150, 81.3%) than matched adjacent tissues (30/150, 20%, p<0.001), whereas IQGAP2 was lower (31/150, 20.7% as compared to 112/150, 74.7%, P<0.001).
Similarly, immunohistochemical staining of 82 HCC samples showed that IQGAP2 protein expression was reduced in 64/82 (78.0%), while IQGAP1 was present in 69/82 (84.1%).
Ectopic expression of miR-124 or miR-203 in HCC cells lacking their expression inhibited cell growth, with direct downregulation of possible targets, cyclin-dependent kinase 6 (CDK6), vimentin (VIM), SET and MYND domain containing 3 (SMYD3) and IQ motif containing GTPase activating protein 1 (IQGAP1) or ATP-binding cassette, subfamily E, member 1 (ABCE1), respectively.
Overexpressing IQGAP1 raised the in vivo tumorigenicity of hepatocellular carcinoma cells, and forced overexpression of IQGAP1 in vitro stimulated cell proliferation.