Genomic Alterations of Signaling and DNA Damage Repair Pathways in Non-Muscle Invasive Bladder Cancer

Area of Science:

• Oncology
• Genetics
• Molecular Biology

Background:

• Non-muscle invasive bladder cancer (NMIBC) requires effective personalized treatment strategies.
• Understanding genetic alterations in key signaling and repair pathways is crucial for targeted therapies.

Purpose of the Study:

• To identify common genetic alterations in phosphatidylinositol-3-OH kinase (PIK3)/AKT/mammalian target of rapamycin (mTOR) signaling and DNA damage repair (DDR) pathways in NMIBC.
• To evaluate BARD1 and PARP4 as potential therapeutic targets for personalized treatment.
• To assess the significance of high tumor mutation burden (TMB) for immunotherapy in NMIBC.

Main Methods:

• Genetic analysis of PIK3/AKT/mTOR and DDR pathways in NMIBC patient samples.
• Correlation of specific gene alterations (BARD1, PARP4) with clinical risk stratification (low/intermediate/high).
• Evaluation of potential therapeutic targets, including PARP-inhibitors and immunotherapy based on TMB.

Main Results:

• Alterations in PIK3/AKT/mTOR and DDR pathways were found in 89.5% and 100% of NMIBC patients, respectively.
• BARD1 alterations were more prevalent in low/intermediate-risk NMIBC, while PARP4 alterations were more common in intermediate/high-risk NMIBC.
• High TMB was identified as an important factor for immunotherapy response in NMIBC.

Conclusions:

• Targeting PIK3/AKT/mTOR and DDR pathways, specifically BARD1 and PARP4, holds promise for personalized NMIBC treatment.
• PARP-inhibitors may be a viable therapeutic option for NMIBC patients with specific BARD1 or PARP4 alterations.
• Assessing TMB is essential for selecting NMIBC patients who may benefit from immunotherapy.