Synergistic effects and mechanism of recombinant viral vector-mediated STAT1 overexpression and STAT3 silencing on glioma U251 apoptosis.

Background: In the present study, the synergistic effects and mechanism of recombinant viral vector-mediated co-expression plasmids stat1 and stat3-siRNA on glioma were investigated in vivo and in vitro.

Methods: Co-expression plasmids for stat1/stat3-siRNA were constructed and packaged into lentivirus and adenovirus for cell and animal experiments. Real-time PCR and Western blot analyses were used to detect the expression of STAT1 and STAT3 at gene and protein levels in U251 cells. CCK-8, TUNEL, flow cytometry, and cell scratching assays were performed to detect the therapeutic effect of the co-expression plasmid stat1/stat3-siRNA on glioma in vitro. U251 glioma cells were injected into nude mice to observe therapeutic effect of stat1/stat3-siRNA.Transcriptome sequencing was utilized to further explore the possible mechanism.

Results: Treatment of glioma cells and xenograft animal model with the co-expression plasmid stat1/stat3-siRNA led to a significant increase in STAT1 and a marked decrease in STAT3 expression at both mRNA and protein expression levels. Compared to the single-gene stat1 and stat3-siRNA groups, stat1/stat3-siRNA group demonstrated a more pronounced promoting apoptosis of U251, but cell viability and migration, as well as reduced tumor growth in nude mice were not significant. Transcriptome sequencing results indicated that the modulation of multiple nodes within the FOXO signaling pathway may represent the main mechanism by which co-expression of lenti-stat1/stat3-SiRNA induces U251 cell apoptosis.

Conclusions: The co-expression plasmid stat1/stat3-siRNA significantly induces apoptosis more effectively than individual stat1 and stat3-siRNA constructs. The potential mechanism involves the alternation of multiple nodes in the FOXO signaling pathway.