Targeting super-enhancer-driven SKIL transcription by CDK7 inhibitor THZ1 to suppress gastric cancer progression.

BACKGROUND

Gastric cancer (GC) is a lethal malignancy characterized by high incidence, mortality, and limited treatment options. Transcriptional addiction is a key cancer hallmark that drives tumor pathogenesis, making its inhibition a promising therapeutic strategy for GC. The study aims to investigate the roles and mechanisms of super-enhancer (SE)-driven oncogenic transcriptional addiction in GC progression and to identify novel targetable vulnerabilities.

METHODS

We utilized cellular and animal models to assess the effects of THZ1 treatment and CDK7 knockdown on GC progression. RNA sequencing was employed to elucidate the potential molecular mechanism of THZ1 treatment. ChIP-seq was performed to establish SE landscape in GC. Integrative analysis of transcriptomic and SE profiling was used to identify THZ1-targeted oncogenic genes. Rescue experiments were conducted to confirm that THZ1 treatment suppresses GC malignant progression by targeting SE-driven SKIL transcription.

RESULTS

GC cells exhibited pronounced sensitivity to THZ1 compared to normal gastric mucosa cells, and the treatment potently suppressed tumor growth and migration in both cellular and animal models. CDK7 was significantly upregulated in GC tissues, and its knockdown inhibited malignant progression in vitro and in vivo, whereas its overexpression accelerated tumor progression. Mechanistically, SE-driven oncogenic transcriptional amplification underlies GC cell susceptibility to THZ1, supported by the identification of novel oncogenic genes such as SKIL. SKIL, a key Hippo pathway regulator, was highly expressed in GC cells, and its elevated expression predicted poor patient prognosis. SKIL silencing attenuated malignant phenotypes, while its overexpression diminished THZ1’s suppression of GC cell proliferation and migration.

CONCLUSION

Our findings demonstrate that THZ1 inhibits GC progression by disrupting SE-driven oncogenic transcription, thereby offering CDK7 inhibition as a promising therapeutic intervention for GC.