Gene expression profile analysis of dbpA knockdown in colorectal cancer cells

Role of zonula occludens in gastrointestinal and liver cancers

A growing body of evidence suggests that tight junction (TJ) proteins play a crucial role in the pathogenesis of various diseases, including gastrointestinal (GI) cancer and hepatocellular carcinoma (HCC). TJ proteins primarily maintain the epithelial and endothelial cells intact together through integral proteins however, recent reports suggest that they also regulate gene expression necessary for cell proliferation, angiogenesis, and metastasis through adapter proteins such as zonula occludens (ZO). ZO proteins are membrane-associated cytosolic scaffolding proteins that modulate cell proliferation by interacting with several transcription factors. Reduced ZO proteins in GI cancer and HCC are correlated with tumor development and poor prognosis. Pubmed has searched for using the keyword ZO and gastric cancer, ZO and cancer, and ZO and HCC for the last ten years to date. This review summarized the role of ZO proteins in cell proliferation and their expression in GI cancer and HCC. Furthermore, therapeutic interventions targeting ZO in GI and liver cancers are reviewed.

Targeting the Y-box Binding Protein-1 Axis to Overcome Radiochemotherapy Resistance in Solid Tumors

Multifunctional Y-box binding protein-1 (YB-1) is highly expressed in different human solid tumors and is involved in various cellular processes. DNA damage is the major mechanism by which radiochemotherapy (RCT) induces cell death. On induction of DNA damage, a multicomponent signal transduction network, known as the DNA damage response, is activated to induce cell cycle arrest and initiate DNA repair, which protects cells against damage. YB-1 regulates nearly all cancer hallmarks described to date by participating in DNA damage response, gene transcription, mRNA splicing, translation, and tumor stemness. YB-1 lacks kinase activity, and p90 ribosomal S6 kinase and AKT are the key kinases within the RAS/mitogen-activated protein kinase and phosphoinositide 3-kinase pathways that directly activate YB-1. Thus, the molecular targeting of ribosomal S6 kinase and AKT is thought to be the most effective strategy for blocking the cellular function of YB-1 in human solid tumors. In this review, after describing the prosurvival effect of YB-1 with a focus on DNA damage repair and cancer cell stemness, clinical evidence will be provided indicating an inverse correlation between YB-1 expression and the treatment outcome of solid tumors after RCT. In the interest of being concise, YB-1 signaling cascades will be briefly discussed and the current literature on YB-1 posttranslational modifications will be summarized. Finally, the current status of targeting the YB-1 axis, especially in combination with RCT, will be highlighted.

YBX3 Mediates the Metastasis of Nasopharyngeal Carcinoma via PI3K/AKT Signaling

The metastasis of nasopharyngeal carcinoma (NPC) is a complex process associated with oncogenic dysfunction, the deciphering of which remains a challenge and requires more in-depth studies. Y-box protein 3 (YBX3) is a DNA/RNA binding protein associated with gene transcription, DNA repair, and the progression of various diseases. However, whether and how YBX3 affects the metastasis of NPC remains unknown. Thus, in this study, we aimed to investigate the role of YBX3 in the metastasis of NPC and determine its underlying mechanism. Interestingly, it was found that the expression of YBX3, which was associated with NPC metastasis, was upregulated in the clinical NPC tissues and cell lines. Moreover, we found that knockdown of YBX3 expression by lentivirus shRNA significantly suppressed NPC cells migration in vitro and metastasis in vivo. Mechanistically, RNA sequencing results suggested that the genes regulated by YBX3 were significantly enriched in cell adhesion molecules, cAMP signaling pathway, calcium signaling pathway, focal adhesion, PI3K/AKT signaling pathway, Ras signaling pathway, Rap1 signaling pathway, NF-κB signaling pathway, and Chemokine signaling pathway. Of these, PI3K/AKT signaling pathway contained the most genes. Accordingly, YBX3 knockdown decreased the activation of PI3K/AKT signaling pathway, thereby inhibit epithelial-to-mesenchymal transition (EMT) and MMP1. These results have demonstrated that YBX3 are involved in the metastasis of NPC through regulating PI3K/AKT signaling pathway, and serve as a potential therapeutic target for patients with NPC.

Knockdown of DNA-binding protein A enhances the chemotherapy sensitivity of colorectal cancer via suppressing the Wnt/β-catenin/Chk1 pathway

DNA-binding protein A (dbpA) is reported to be upregulated in many cancers and associated with tumor progress. The present study aimed to investigate the role of dbpA in 5-fluorouracil (5-FU)-resistant and oxaliplatin (L-OHP)-resistant colorectal cancer (CRC) cells. We found that 5-FU and L-OPH treatment promoted the expression of dbpA. Enhanced dbpA promoted the drug resistance of SW620 cells to 5-FU and L-OHP. DbpA knockdown inhibited cell proliferation, induced cell apoptosis, and cell cycle arrested in SW620/5-FU and SW620/L-OHP cells. Besides, dbpA short hairpin RNA (shRNA) enhanced the cytotoxicity of 5-FU and L-OHP to SW620/5-FU and SW620/L-OHP cells. Meanwhile, dbpA shRNA inhibited the activation of the Wnt/β-catenin pathway that induced by 5-FU stimulation in SW620/5-FU cells. Activation of the Wnt/β-catenin pathway or overexpression of checkpoint kinase 1 (Chk1) abrogated the promoting effect of dbpA downregulation on 5-FU sensitivity of CRC cells. Importantly, downregulation of dbpA suppressed tumor growth and promoted CRC cells sensitivity to 5-FU in vivo. Our study indicated that the knockdown of dbpA enhanced the sensitivity of CRC cells to 5-FU via Wnt/β-catenin/Chk1 pathway, and DbpA may be a potential therapeutic target to sensitize drug resistance CRC to 5-FU and L-OHP.