HBXIP: a potential prognosis biomarker of colorectal cancer which promotes invasion and migration via epithelial-mesenchymal transition

HBXIP knockdown inhibits FHL2 to promote cycle arrest and suppress cervical cancer cell proliferation, invasion and migration

Hepatitis B X-interacting protein (HBXIP) and four and a half LIM domain 2 (FHL2) have been reported to serve as independent biomarkers for cervical cancer. The present study evaluated the effects of HBXIP on cervical cancer in terms of its cellular malignant characteristics. Reverse transcription-quantitative PCR and western blotting were used to assess the mRNA and protein expression levels of HBXIP and FHL2 in the human endocervical epithelial End1/E6E7 cell line and the cervical cancer HeLa, CaSki, C33A and SiHa cell lines. After knocking down HBXIP expression by transfection of small interfering RNAs targeting HBXIP, cell cycle progression was assessed using flow cytometry with PI staining. Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine staining, wound healing and Transwell assays were used to assess cell proliferation, migration and invasion, respectively. Furthermore, co-immunoprecipitation assay was used to evaluate the potential binding relationship between HBXIP and FHL2. Western blotting was used for the analysis of HBXIP and FHL2, cell cycle-associated proteins, including cyclin D1 and cyclin D2, metastasis-associated proteins, including MMP2 and MMP9, and Wnt/β-catenin signaling-associated proteins, including β-catenin and c-Myc. Both HBXIP and FHL2 were found to be highly expressed in cervical cancer cells compared with that in the human endocervical epithelial cell line. HBXIP knockdown suppressed the proliferation, invasion and migration of HeLa cells, but promoted cell cycle arrest at the G₀/G₁ phase. HBXIP was demonstrated to interact with FHL2, and HBXIP knockdown also inhibited FHL2 mRNA and protein expression. By contrast, FHL2 overexpression reversed the inhibitory effects of HBXIP knockdown on the malignant characteristics of cervical cancer cells. Furthermore, HBXIP knockdown blocked the Wnt/β-catenin signaling pathway in HeLa cells, which was also partially reversed by FHL2 overexpression; the decreased β-catenin and c-Myc expression caused by HBXIP knockdown was increased again after FHL2 was overexpressed. In conclusion, these results suggest that HBXIP knockdown suppressed the malignant characteristics of cervical cancer cells through the downregulation of FHL2 expression, indicating a promising insight into the therapeutic target of cervical cancer.

Insulin-induced gene 2 expression is associated with cervical adenocarcinoma malignant behavior

BACKGROUND

The incidence of cervical adenocarcinoma (CA) as a malignant tumor has increased over the past few decades due to its low detection rate and malignant biological behaviors. Insulin-induced gene 2 (INSIG2), a membrane protein of the endoplasmic reticulum (ER), plays a crucial role in cancer progression. However, there is little known about the connection between INSIG2 and CA.

METHODS

The Human Protein Atlas (HPA) and the Cancer Genome Atlas (TCGA) Cervical Cancer (CESC) data were applied to study the alteration in INSIG2 expression. Biological functions were performed to test the change of malignant behavior. Bioinformatics analysis was conducted to explore the potential affection of INSIG2 in CA progression.

RESULTS

Our study confirmed that the high INSIG2 expression levels had a poor prognosis. INSIG2-knockdown inhibited the CA cell proliferation, migration, and invasion of CA cells while downregulating the epithelial-mesenchymal transition (EMT)-associated gene expression levels. Moreover, the enrichment analysis of DEGs showed more potential functions of INSIG2 in the CA progression.

CONCLUSION

We found that INSIG2 knockdown may play a suppressor role in the CA progression, and may provide the potential functional influence in inhibiting of CA development.

The oncogenic role of HBXIP

Hepatitis B X-interacting protein (HBXIP) is a conserved protein of 19 kDa that was originally identified as a binding partner of hepatitis B virus X protein. Emerging evidence indicates that HBXIP is highly expressed in a variety of cancers and is correlated with poor clinical outcomes in cancer patients. HBXIP plays a critical role in cancer progression, but the underlying mechanisms are still unclear. In this review, we primarily focus on publications investigating HBXIP in cancer research, including its expression and clinical significance in cancer patients, its role as a coactivator of transcription factors in cancer cells, its inhibitory effects on the mitochondrial cytochrome c-caspase apoptotic pathway, as well as its roles in promoting mitosis and drug resistance in cancer cells, its regulatory effects on cancer metabolism, and its relationships with other signaling pathways or microRNAs in cancer. This review aims to compile and summarize existing knowledge of the functions of HBXIP in cancer, which provides a comprehensive reference for future studies on the oncogenic mechanisms of HBXIP.