Hepatocellular carcinoma (HCC) is the most common primary liver cancer and an important medical problem. The mortality rate has increased in recent years. (Vogel et al., 2022)。As a major risk factor for the occurrence and progression of HCC, HBV infection poses a threat to human life and health. HBV infection can directly or indirectly promote hepatocellular carcinogenesis. At the genetic level, HBV can increase the instability of the host cell genome, cause epigenetic remodeling of the host DNA, and lead to chromosomal remodeling and abnormal expression of oncogenes and tumor suppressor genes by integrating or inducing host gene mutations. It can also activate various cancer-related signaling pathways, regulate cell metabolism and other mechanisms to cause malignant transformation of liver cells. It is of great significance to study the specific mechanism of the occurrence and progression of HBV-HCC for its prevention and treatment. In the liver microenvironment, chronic inflammation induced by HBV infection, changes in the interaction between the virus and innate immune cells and adaptive immune cells help the virus evade immune surveillance and promote the evolution of the disease from inflammation to tumor formation(Levrero and Zucman-Rossi, 2016). Further study of the mechanism of HBV infection-induced HCC can provide reliable new ideas and methods for the prevention, diagnosis and treatment of HBV-HCC.
With the development of gene sequencing technology and various deep learning algorithms, it provides a method for identifying new biomarkers in diseases. In this study, three deep learning methods, random forest, Lasso regression and SVM-RF, were used to identify the key genes RACGAP1, ECT2 and NDC80 in HBV-HCC-related gene sequencing data. Through difference analysis, it was found that they were highly expressed in tumor tissues compared with normal tissues. Survival analysis showed that its high expression was associated with poor prognosis in patients with liver cancer. The selected three key genes were used to construct a clinical diagnostic model. In the training set, the key genes showed high accuracy in the diagnosis of HBV-HCC, and also had good accuracy in the validation set. It can be concluded from the DCA curve that patients can get better benefits from the model. Lenvatinib, Sorafenib and Regorafenib are clinically used drugs for the systematic treatment of hepatocellular carcinoma, which can improve the survival and prognosis of patients with hepatocellular carcinoma(Villanueva, 2019). Through molecular docking, it was found that the docking configurations of Lenvatinib, Sorafenib and Regorafenib with RACGAP1, ECT2 and NDC80 had strong activity, indicating that the target may be a potential therapeutic target for hepatocellular carcinoma.
RACGAP1 is an important cellular protein. It is a GTPase-activating protein that acts on the Rho GTPase family. It belongs to the GTPase-activating protein family and participates in many cellular processes, including cell division, transformation, and invasive migration(Saigusa et al., 2015), Studies have found that RACGAP1 is highly expressed in a variety of cancers, such as the poor prognosis and adverse clinicopathological features of gastrointestinal stromal tumors with high expression of RACGAP1(Imaoka et al., 2015). RACGAP1 can drive breast cancer metastasis by regulating ECT2-dependent mitochondrial quality control(Yin et al., 2019). RACGAP1 is used as a biomarker for lymphatic metastasis and poor prognosis of colon cancer(Ren et al., 2021). In hepatocellular carcinoma, high expression of RACGAP1 promotes tumor progression, and studies have shown that up-regulation of RACGAP1 is significantly associated with early recurrence of hepatocellular carcinoma(Gu et al., 2022; Zabady et al., 2022). ECT2 is a guanine nucleotide dissociation exchange factor. It is a high incidence area of chromosomal abnormalities in malignant tumors. It is widely present in cells and tissues, and has the effects of regulating cell proliferation, apoptosis and DNA damage repair(Xu et al., 2021). ECT2 has been reported to be overexpressed in a variety of human tumors, such as hepatocellular carcinoma(J. Chen et al., 2015)、prostatic cancer(Guo et al., 2017)、ovary carcinoma(Huff et al., 2013)、oral cancer(Iyoda et al., 2010) And gastric cancer(Wang et al., 2016). Promoting the expression of ECT2 will enhance the proliferation of HCC cells and enhance the metastasis of cancer cells. (He et al., 2022; Lv et al., 2023). NDC80 is a core component of the outer kinetochore and mitogen regulators and is involved in the migration, proliferation, invasion and apoptosis of various types of tumor cells(Ju et al., 2017; J. Chen and Ünal, 2021). High expression of NDC80 enhances cisplatin resistance in triple-negative breast cancer(Li et al., 2022). Overexpression of NDC80 can lead to decreased apoptosis of HCC cells and overcome cell cycle arrest to promote the development of HCC and is associated with poor prognosis in HCC patients(Xie et al., 2020; Ju et al., 2017).
The p53 signaling pathway plays an important role in cell cycle regulation, metabolism, aging development, reproduction and inhibition of tumor expression(Hu et al., 2007; Kruiswijk et al., 2015; Tanikawa et al., 2017). It has been found that p53, as a tumor suppressor, mutates or loses in nearly half of cancers. In the other half of the tumor, although the p53 protein is normal, the upstream regulatory factors and downstream mediators are disordered, resulting in the destruction of the entire p53 pathway(Huang, 2021). Cell cycle is a highly regulated process that makes cell growth, genetic material replication and cell division possible. In the normal cell cycle, the expression of various cell cycle proteins is strictly regulated. However, in tumor cells, the mechanism of cell cycle regulation is disordered, resulting in abnormal activation of cyclins, which plays a pathogenic role in the development of most tumor types(Suski et al., 2021).
The results of GO enrichment analysis showed that the genes interacting with key genes RACGAP1, NDC80 and ECT2 were mainly enriched in chromosome-related pathways. The p53 and cell cycle pathways mainly enriched by KEGG played an important role in the occurrence and progression of cancer. Previous studies have also shown that overexpression of RACGAP1, ECT2 and NDC80 is associated with malignant progression and poor prognosis of HCC. Previous studies have shown that HBV leads to chromosomal remodeling and abnormal expression of oncogenes and tumor suppressor genes by integrating or inducing host gene mutations. It can also activate various cancer-related signaling pathways to promote the occurrence and progression of cancer(Jiang et al., 2021; Jia et al., 2020). The clinical prediction model for the diagnosis of HBV-HCC based on RACGAP1, ECT2 and NDC80 also showed good accuracy.
In summary, according to the results of machine learning and molecular docking, we speculate that HBV may induce gene mutations in RACGAP1, ECT2 and NDC80, affect the normal function of chromosomes, affect the normal regulation of p53 and cell cycle signaling pathways, and then lead to the occurrence and progression of HCC. Moreover, NDC80, RACGAP1 and ECT2 may be valuable diagnostic biomarkers for HBV-HCC and potential therapeutic targets.