Objective Basic transcription factor 3 (BTF3) has been shown to exert carcinogenic effects in several types of tumors. But its role in melanoma is still unclear. This study aims to explore the proliferative effect and molecular mechanisms of BTF3 in melanoma. Methods We used GFP-labeled BTF3-shRNA lentiviral vectors to knock down the expression of the BTF3 gene in melanoma cells, and then evaluated the effect of BTF3 on the cell proliferation, cell cycle, apoptosis, and colony formation of melanoma cells through in vivo and in vitro experiments. Furthermore, we selected the representative tumor masses from the xenografted melanoma for microarray hybridization and bio-information analysis to screen out genes that significantly interact with BTF3. Through conducting hierarchical clustering analyze we predicted the prominent pathways and biological effects of BTF3-ralated genes, and further verify the expression of some representative genes by qRT-PCR and western blot. Results BTF3 is heterogeneously expressed in melanoma tissues and cells. Knockdown the expression of BTF3 attenuated the proliferation of melanoma cells both in vitro and in vivo. The melanoma cells exhibited more apoptosis, significant G2/M arrest, and deficient DNA damage repair capability conferred by transfection of BTF3-shRNA lentiviral vector. Furthermore, the results of bioinformatics analysis and western blot assay suggested that BTF3 might involve in p53 signaling, complement system, wnt/β-catenin signaling, FGF signaling, and other classical signaling pathways through interacting with some important genes such as TP53, cyclin dependent kinase inhibitor 1A (CDKN1A), checkpoint kinase 1 (CHEK1), tumor protein p53 inducible protein 3 (TP53I3), and insulin like growth factor binding protein 3 (IGFBP3). The upstream regulators of BTF3 include doxorubicin, nuclear protein 1 (NUPR1), TP53, etc. Conclusion BTF3 promotes the progression of melanoma by interacting with some key genes such as p53. Our findings provide novel insights into the role of BTF3 as an oncogenic gene in melanoma and suggest that BTF3 expression level may serve as a potential biomarker in response to clinical treatment.

Irinotecan (CPT-11) is a classic chemotherapeutic agent that plays an important role in the clinical treatment of metastatic colon cancer and other malignant tumors. We previously designed a series of novel irinotecan derivatives and selected one representative, ZBH-01, to investigate its sophisticated antitumor mechanisms in colon tumor cells. Our current results showed that ZBH-01 has superior antitumor activity against colon cancer cells compared to CPT-11 and SN38 (7-Ethyl-10-hydroxy camptothecin), both in vivo and in vitro. However, its inhibitory ability on topoisomerase I (TOP1) was weaker than these two control drugs. Moreover, 842 mRNAs were downregulated and 927 were upregulated in the ZBH-01-treated group by Next-Generation Sequencing (NGS) and bioinformatics analysis. The most significantly enriched KEGG pathways for these dysregulated mRNAs were DNA replication, the p53 signaling pathway, and the cell cycle. Then, we constructed a protein-protein interaction (PPI) network and identified a significant cluster containing 73 genes, including 14 involved in the cell cycle process. ZBH-01 induced G0/G1 phase arrest and enhanced the levels of p53 protein in colon cancer cells, while CPT-11/SN38 caused S phase arrest. The initiation of apoptosis by ZBH-01 was also superior to CPT-11/SN38, followed by the increased expression of Bax, active caspase 3, and cleaved-PARP, and decreased expression of Bcl-2. Additionally, CCNA2 (cyclin A2), CDK2 (cyclin-dependent kinase 2), and MYBL2 (MYB proto-oncogene like 2) might be involved in the G0/G1 cell cycle arrest induced by ZBH-01. Overall, ZBH-01 can be an antitumor candidate drug for preclinical study in the future.