GSE160089
Pharmacological target dysfunction cell  cycle pathways induce vulnerabilities of chemotherapy in colorectal cancer
Dysfunction of cell cycle genes can lead to mitosis disruption and chromosomal instability (CIN), which is blamed for poor prognosis in colorectal cancer (CRC) patients, no matter with chemotherapy or not. Discovery therapeutic targets to abnormal cell cycle pathways in CRC may help to improve current therapy. By genome-widely profiling of differential expressed genes in 54 pairs of human colorectal tumor with matched normal mucosa, we found a functional enrichment in PLK1 signaling. Tumors with enriched PLK1 signaling are accompanied with dysfunction pathways related to cell cycle. Total PLK1 and phosphorylated PLK1 protein expression are associated with tumor recurrence and poor overall survival in a cohort of CRC patients. Combining PLK1 inhibitor with oxaliplatin shows a synergize effect to suppress the growth of CRC cell lines, xenograft tumors, preclinical patient-derived organoid and patient-derived xenograft tumors. RNA-seq data reveals that the cell cycle pathways were activated in oxaliplatin group but inhibited after PLK1 inhibitor treatment.  CDC7 may be a key downstream effector of PLK1 induced oxaliplatin resistance and can be druggable. Further investigation showed that PLK1 inhibitor suppress the CDC7 expression via c-MYC transcriptional control. A strong positive correlation between PLK1 and CDC7 has been further confirmed in patients. Strikingly, functional studies confirm that combining CDC7 inhibitor with oxaliplatin can recapitulate the synergize effect in various CRC models, highlighting pharmacological target PLK1-MYC-CDC7 signaling as a potential therapeutic strategy for oxaliplatin based chemotherapy. Overall design: RNA-seq for DLD1 cells upon treatment of oxaliplatin and volasertib.