Soluble Guanylate Cyclase ß1 Subunit Represses Human Glioblastoma Growth.

ABSTRACT

Malignant glioma is the most common and deadly brain tumor. A marked reduction in the levels of sGC (soluble guanylyl cyclase) transcript in the human glioma specimens has been revealed in our previous studies. In the present study, restoring the expression of sGCß1 alone repressed the aggressive course of glioma. The antitumor effect of sGCß1 was not associated with enzymatic activity of sGC since overexpression of sGCß1 alone did not influence the level of cyclic GMP. Additionally, sGCß1-induced inhibition of the growth of glioma cells was not influenced by treatment with sGC stimulators or inhibitors. The present study is the first to reveal that sGCß1 migrated into the nucleus and interacted with the promoter of the TP53 gene. Transcriptional responses induced by sGCß1 caused the G0 cell cycle arrest of glioblastoma cells and inhibition of tumor aggressiveness. sGCß1 overexpression impacted signaling in glioblastoma multiforme, including the promotion of nuclear accumulation of p53, a marked reduction in CDK6, and a significant decrease in integrin α6. These anticancer targets of sGCß1 may represent clinically important regulatory pathways that contribute to the development of a therapeutic strategy for cancer treatment.