PGCC development and recovery within a prostate cancer cell population

Polyploid Giant Cancer Cells (PGCC) are increasingly being studied for their role in cancer recurrence and mortality. PGCC arise from cancer cells in response to stress such as radiation, chemotherapy, or hypoxia. PGCC remain viable but do not divide by mitosis. However, upon cessation of stress, PGCC are capable of progeny formation via primitive, amitotic mechanisms akin to budding or bursting. In this study, the initial PGCC offspring are referred to as “early progeny”. As early progeny cells resume proliferation they generate “late progeny”. This study assessed the transcriptional changes that occur as parental cancer cells progress to PGCC in response to radiation stress, escape as early progeny, and resume proliferation. Overall design: The experiment included four conditions. For each, 7 X 10^5 PPC1 cells were plated on day 1 in 100 mm plates. Condition 1 (UT) were simply harvested on day 4 with trypsinization, processed using a Qiagen RNAEasy kit, purity assessed with a Nanodrop, and packaged for delivery to Novogene for analysis. Condition 2 (Gi) were irradiated with 8 Gy on day 2 and on day 4 trypsinized, passed through a 20 micron PluriSelect cell filter, and the captured cells eluted. Condition 3 (ErD) were irradiated on day 2 and on day 8 trypsinized, passed through a 20 micron PluriSelect cell filter, and the flowthrough processed for analysis. Condition 4 (Late) were irradiated on day 2 and on day 20 trypsinized, passed through a 20 micron PluriSelect filter, and the flowthrough processed. The experiment was performed with 6 replicates, for a total of 24 samples.