[Research progress on genome-guided precision oncology and development ideas of antitumor Chinese medicine].

Genome-guided oncology refers to a new treatment concept that transcends histological classification and pathological ty-ping and uses drugs according to the genetic characteristics of tumors. New drug development technology and clinical trial design based on this concept provide new ideas for the clinical application of precision oncology. The multi-component and multi-target characteristics of Chinese medicine provide rich resources for the development of tumor-targeting drugs from natural products, and the design of the master protocol trial aiming at the characteristics of precision oncology supports the rapid clinical screening of effective tumor-targeting drugs. The emergence of the synthetic lethality strategy breaks through the bottleneck that the drug can only target the oncogene but cannot do anything to the tumor suppressor gene with the loss-of-function mutation in the past. With the rapid development of high-throughput sequencing technology, the cost of sequencing is also decreasing. For the development of tumor-targeting drugs, how to keep up with the update speed of target information is a difficult problem of concern. Based on the integration of innovative ideas and me-thods of precision oncology, network pharmacology, and synthetic lethality strategy on synthetic lethal interaction network of antitumor Chinese medicine compatibility formula design, and the combination of improvement of innovative clinical trial methods, such as master protocol trial, basket trial, and umbrella trial, unique advantages of Chinese medicine are expected to be exerted beyond the antibody-based drugs and small molecule-based drugs and corresponding targeted drugs are potentially developed for clinical application.

Potential role of ZEB1 as a DNA repair regulator in colorectal cancer cells revealed by cancer-associated promoter profiling.

Besides being a key contributor to epithelial­to­mesenchymal transition (EMT) activation and stemness maintenance, zinc finger E-box binding homeobox 1 (ZEB1) is also a crucial inducer of chemoresistance and radioresistance. Unlike the clear mechanism that mediates its effect on EMT and dedifferentiation, the mechanism of how ZEB1 promotes chemo- and radio-resistance remains to be elucidated. It has been previously reported that ZEB1 promotes DNA double-strand break clearance by enhancing the deubiquitylating activity of ubiquitin-specific peptidase (USP)7 on checkpoint kinase 1, which is an important step during DNA repair. It was hypothesized that as a transcriptional suppressor, ZEB1 may be involved in an unbalanced DNA damage response (DDR) by affecting other key components. Therefore, in the present study, the target gene occupancy of ZEB1 was mapped in colorectal cancer cells using the ChIP-on-chip method, revealing positive intervals enriched along the three DDR-associated genes: USP17, chromodomain helicase DNA-binding protein 1-like and double homeobox 4. The E-boxes identified in the binding regions and the enhanced mRNA expression of the three genes following the knockdown of ZEB1 supported the identification of these three genes as downstream target genes of ZEB1. Furthermore, ZEB1 knockdown initiated a chemosensitization effect, induced G1/S arrest and increased apoptosis, which functionally validated the three ZEB1 downstream targets. In summary, the present study identified three DDR-associated genes as ZEB1 downstream targets, and demonstrated that their suppression by ZEB1 contributes to ZEB1-mediated chemoresistance.

Xihuang Pill () induces mesenchymal-epithelial transition and inhibits loss of apical-basal polarity in colorectal cancer cell through regulating ZEB1-SCRIB loop.

OBJECTIVE: To investigate the antiproliferative and anti-metastasis effect of Xihuang Pill (, XP) on human colorectal cancer cell and to explore the molecular mechanism by which it produces the effects. METHODS: Highly metastatic human colorectal cancer cell line LoVo was treated with low-, medium-, and highdose XP-containing serum (XP-L, XP-M, XP-H) groups for 48 h, cells intervened with no drug rat serum and PD98059 [extracellular signal-regulated kinase (ERK) inhibitor] as negative and positive controls (NC and PC) groups. Cell proliferation assay was made using cell counting kit-8 (CCK8). The 8 µm pore-size transwell chamber and 4', 6-diamidino-2-phenylindole (DAPI) staining were applied to examine the ability of invasion and migration of the cells. The protein expression of ERK1/2, zinc fifi nger E-box-binding homeobox 1 (ZEB1), Scrib and lethal giant larvae homolog 2 (Lgl2) was detected by Western blotting while the relative mRNA quantity of E-cadherin, N-cadherin, Occludin and junctional adhesion molecule-1 (JAM1) was measured by realtime fluorescent quantitative polymerase chain reaction (RT-qPCR). RESULTS: XP induced a dose-dependent suppression on the proliferation of LoVo cells (P <0.05 or P<0.01), with the inhibition rates varied from 27.30% to 31.08%. Transwell assay showed that when preprocessed with PD98059 and XP-containing serum, the number of cells that passed the filter decreased significantly compared with that of NC group (P <0.05 or P<0.01). Moreover, XP inhibited the protein expression of ERK1/2 and ZEB1 (P <0.05); and up-regulated the protein expression of Scrib and Lgl2 (P <0.05). The mRNA levels of E-cadherin, Occludin and JAM1 of the XP intervened groups and PC group markedly ascended (P <0.05) while that of N-cadherin showed a descending tendency (P>0.05). CONCLUSION: XP intervention suppressed the ability of proliferation, invasion and migration of the LoVo cells. Regulating ZEB1-SCRIB Loop so as to recover epithelial phenotype and apical junctional complex might be one of the mechanisms by which XP produces the anti-metastasis effect.