n(1)-guanyl-1-7-diaminoheptane and Liver-Neoplasms

Eukaryotic translation initiation factor 5A2 (eIF5A2) has been identified as a critical gene in tumor metastasis. Research has suggested that reactive oxygen species (ROS) serve as signaling molecules in cancer cell proliferation and migration. However, the mechanisms linking eIF5A2 and ROS are not fully understood. Here, we investigated the effects of ROS on the eIF5A2-induced epithelial-mesenchymal transition (EMT) and migration in six hepatocellular carcinoma (HCC) cell lines. Western hybridization, siRNA transfection, transwell migration assays, wound-healing assays, and immunofluorescence analysis were used. The protein levels of eIF5A2 in tumor and adjacent tissue samples from 90 HCC patients with detailed clinical, pathological, and clinical follow-up data were evaluated. Overexpression of eIF5A2 was found in cancerous tissues compared with adjacent tissues. We found that eIF5A2 overexpression in HCC was associated with reduced overall survival. Knockdown of eIF5A2 and intracellular reduction of ROS significantly suppressed the invasion and metastasis of HCC cells. Interestingly, N1-guanyl-1, 7-diaminoheptane (GC7) suppressed the intracellular ROS levels. After blocking the EMT, administration of GC7 or N-acetyl-L-cysteine did not reduce cell migration further. Based on the experimental data, we concluded that inhibition of eIF5A2 alters progression of the EMT to decrease the invasion and metastasis of HCC cells via ROS-related pathways.

Topics: Acetylcysteine; Blotting, Western; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Movement; Epithelial-Mesenchymal Transition; Eukaryotic Translation Initiation Factor 5A; Guanine; Hep G2 Cells; Humans; Kaplan-Meier Estimate; Liver Neoplasms; Neoplasm Invasiveness; Peptide Initiation Factors; Reactive Oxygen Species; RNA Interference; RNA-Binding Proteins; Signal Transduction

Hepatocellular carcinoma (HCC) cells undergo the epithelial-mesenchymal transition (EMT) during chemotherapy, which reduces the efficacy of doxorubicin-based chemotherapy. We investigated N1-guanyl-1,7-diaminoheptane (GC7) which inhibits eukaryotic translation initiation factor 5A2 (eIF5A2) activation; eIF5A2 is associated with chemoresistance. GC7 enhanced doxorubicin cytotoxicity in epithelial HCC cells (Huh7, Hep3B and HepG2) but had little effect in mesenchymal HCC cells (SNU387, SNU449). GC7 suppressed the doxorubicin-induced EMT in epithelial HCC cells; knockdown of eIF5A2 inhibited the doxorubicin-induced EMT and enhanced doxorubicin cytotoxicity. GC7 combination therapy may enhance the therapeutic efficacy of doxorubicin in HCC by inhibiting eIF5A2 activation and preventing the EMT.

Topics: Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Hepatocellular; Doxorubicin; Epithelial-Mesenchymal Transition; Eukaryotic Translation Initiation Factor 5A; Guanine; Hep G2 Cells; Humans; Liver Neoplasms; Peptide Initiation Factors; RNA-Binding Proteins

A high incidence of tumor recurrence and metastasis has been reported in hepatocellular carcinoma (HCC) patients; however, the underlying molecular mechanisms are largely unknown. In the present study a novel metastasis-related gene, eukaryotic initiation factor 5A2 (EIF5A2), was characterized for its role in HCC metastasis and underlying molecular mechanisms. Overexpression of EIF5A2 messenger RNA (mRNA) was detected in 50/81 (61.7%) of HCCs, which was significantly higher than those in nontumorous liver tissues. Compared with matched primary HCC, higher expression of EIF5A2 protein was observed in 25/47 (53.2%) of metastatic tumors. Functional studies found that ectopic expression of EIF5A2 could enhance cancer cell migration and invasion in vitro and tumor metastasis in vivo in an experimental mouse model. Moreover, inhibition of EIF5A by small interfering RNA (siRNA) or deoxyhypusine synthase (DHPS) inhibitor GC7, which inhibits EIF5A2 maturation, could effectively decrease cell motility. Further study found that EIF5A2 was able to induce epithelial-mesenchymal transition (EMT), a key event in tumor invasion and metastasis, characterized by down-regulation of epithelial markers (E-cadherin and beta-catenin) and up-regulation of mesenchymal markers (fibronectin, N-cadherin, alpha-SMA, and vimentin). In addition, EIF5A2 could also activate RhoA/Rac1 to stimulate the formation of stress fiber and lamellipodia.. EIF5A2 plays an important role in HCC invasion and metastasis by inducing EMT, as well as stimulating cytoskeleton rearrangement through activation of RhoA and Rac1.

Topics: Adult; Aged; Animals; Carcinoma, Hepatocellular; Cell Movement; Epithelial Cells; Female; Guanine; Humans; Liver Neoplasms; Male; Mesoderm; Mice; Middle Aged; Oxidoreductases Acting on CH-NH Group Donors; Peptide Initiation Factors; rho GTP-Binding Proteins; RNA, Small Interfering