Combination of Compound Kushen Injection and cisplatin shows synergistic antitumor activity in p53-R273H/P309S mutant colorectal cancer cells through inducing apoptosis

Ethnopharmacological relevance: Colorectal Cancer (CRC) is one type of worldwide popular and refractory tumors. Compound Kushen Injection (CKI) is a frequently applied traditional Chinese medicine formula as an adjuvant drug for the chemotherapy of CRC. P53 is the most commonly mutated gene in CRC, accounting for the development, malignant and prognosis progression of CRC. However, effect of CKI on the therapeutic efficacy of p53-mutant CRC remains understood. Besides, the combined efficacy of different chemotherapeutics drugs in combination with CKI for CRC treatment is rarely concerned.

Aim of study: To investigate the combined efficacy of the CKI-derived combination strategies in the p53-mutant CRC.

Materials and methods: Two CRC cell lines HCT116 and SW480 cells, which respectively harbor wild-type p53 and p53-R273H/P309S mutant, were applied. Cisplatin (Cis) and 5-fluorouracil (5FU) were combined chemotherapeutics drugs of CKI-derived combination strategies in this article. In vitro antitumor activity was detected by sulforhodamine B (SRB) assay and colony formation assay. Combenefit soft was applied to evaluate the synergetic/antagonistic effect of drug combination. Lentivirus-mediated overexpression method was used to generate a set of p53-mutant and wild-type CRC cell lines harboring identical genomes. Transcriptomics and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were applied to predicate the underlying mechanism of synergetic interaction between drug combination. Western blot was performed to verify predicated pathways contributing to the synergy of drug combination.

Results: CKI preferentially combined with Cis but not 5FU, to produce a synergistical antitumor efficiency for p53-R273H/P309S mutant, rather than wild-type p53 harboring CRC cells. The combination of CKI and Cis strongly reprogrammed the transcriptional profiles of SW480 cells. Cytokine-cytokine receptor interaction pathway was a key pathway involved in cooperativity between CKI and Cis in SW480 cells. Mechanistically, compared to that Cis individually triggered Necroptosis, the co-treatment of CKI and Cis reinforced the cell death of SW480 cells in a possible synergistic manner by inducing extrinsic Apoptosis pathway.

Conclusion: This article provides a novel perspective into the precision clinical application of CKI-derived combination therapy programs of CRC based on genetic variation and the classes of chemotherapeutics drugs.