Pericentriolar material 1 aggregation maintains cell survival upon prolonged replication stress

Area of Science:

• Cell Biology
• Cancer Biology
• Molecular Biology

Background:

• Centrosome duplication is critical for cell division and requires precise copy number control.
• Pericentriolar material 1 (PCM1) is a component of centriolar satellites involved in centrosome and cilia regulation.
• Previous studies suggested PCM1 aggregation drives centrosome amplification, but potential off-target effects of reagents were noted.

Purpose of the Study:

• To investigate the role of PCM1 aggregation in centrosome amplification.
• To determine PCM1's function in cancer cell survival under replication stress.

Main Methods:

• Disruption of PCM1 aggregation via microtubule or dynactin inhibition, or PCM1 depletion.
• Assessment of centrosome copy numbers under replication stress in U2-OS and PANC-1 cells.
• Analysis of DNA damage signaling (ATM-CHK1 axis) and autophagy in PCM1-depleted cells.

Main Results:

• PCM1 aggregation did not promote centrosome amplification in osteosarcoma or pancreatic cancer cells.
• Centrosome amplification was found to promote PCM1 aggregation in a PLK4-dependent manner.
• PCM1 depletion impaired U2-OS cell survival by reducing ATM-CHK1 signaling and autophagy activation during replication stress.

Conclusions:

• PCM1 does not drive centrosome amplification; rather, amplification influences PCM1 aggregation.
• PCM1 is essential for activating the ATM-CHK1 axis and autophagy, crucial for osteosarcoma cell survival under prolonged replication stress.