Effects of targeting endometrial stromal sarcoma cells via histone deacetylase and PI3K/AKT/mTOR signaling

Area of Science:

• Gynecologic Oncology
• Medical Oncology
• Cancer Biology

Background:

• Endometrial stromal sarcoma (ESS) is a rare gynecologic malignancy with limited treatment options.
• Histone deacetylase (HDAC) inhibitors and phosphoinositid-3-Kinase (PI3K) pathway inhibitors are emerging therapeutic agents in oncology.

Purpose of the Study:

• To evaluate the efficacy of suberanilohydroxamic acid (SAHA), an HDAC inhibitor, in combination with PI3K pathway inhibitors for treating ESS.
• To investigate the impact of combined SAHA and PI3K/mTOR inhibition on ESS cell proliferation and signaling pathways.

Main Methods:

• The study utilized two ESS cell lines (ESS-1, MES-SA) and one non-neoplastic cell line (HESC).
• Cells were treated with SAHA alone, PI3K inhibitor (LY294002), mTOR inhibitor (rapamycin), or combinations thereof.
• Effects on cell growth and key signaling pathway components (AKT, mTOR/p70S6K) were assessed.

Main Results:

• SAHA monotherapy inhibited cell growth by downregulating AKT and mTOR/p70S6K signaling.
• Combination therapy with SAHA and LY294002 or rapamycin demonstrated synergistic reduction in p-p70S6K and p-4E-BP1 levels.
• The triple combination of SAHA, LY294002, and rapamycin induced the most potent growth inhibition and slowest recovery.

Conclusions:

• Combined inhibition of PI3K and mTOR pathways with SAHA presents a potential therapeutic strategy for endometrial stromal sarcoma.
• This combination therapy warrants further investigation for clinical application in ESS patients.