Hyperplasia suppressor gene inhibits the proliferation and metastasis of glioma cells by targeting rho family proteins

Aim: To investigate the effect of the hyperplasia suppressor gene (HSG) on human glioma cell invasion and its possible mechanism.

Methods: Human glioma U251 cells were infected with recombinant viral vectors carrying the HSG gene sequence (HSG overexpression group) and HSG interference sequence (HSG suppression group). The negative control group with no-load virus transcription and a blank control group with only PBS treatment were set up. CCK-8 assay, cell scratch healing test, transwell migration, and invasion test were used to detect the effect of HSG expression on proliferation, migration and invasion of U251 glioma cells. Cell immunofluorescence and cell adhesion test were used to analyze the effect of HSG expression on cytoskeleton formation and adhesion ability of U251 cells. Gene chip technology was employed to preliminarily explore the effect of HSG expression change on the inherent gene expression in U251 cells. The expression of Rho family key molecule mRNA and protein was detected by light quantitative PCR and western blot.

Results: After 24 h of transcription with the recombinant virus vector, the cells showed a green color under an inverted fluorescence microscope. HSG expression increased in the HSG overexpression group (P < 0.01), and decreased in the HSG inhibition group (P < 0.01). Compared with the two control groups, the proliferation, scratch healing rate, migrating cell number, invasive cell number and adhesion cell number in the HSG overexpression group were markedly lower. After HSG overexpression, the morphology of U251 cells changed; filamentous pseudopods shortened and partially flaked. However, after HSG inhibition, the pseudopods grew toward both ends and were arranged axially. The overexpression of HSG inhibited the expression of rho family proteins (RhoA, Rock1, Rock2, Rac1, and Cdc42).

Conclusion: The overexpression of HSG inhibits the progression of glioma U251 cells by regulating the expression of rho family proteins.