miR-708-3p promotes gastric cancer progression through downregulating ETNK1

MicroRNAs (miRNAs) are small, evolutionarily conserved, non-coding RNAs playing a role in the proliferation, metastasis, apoptosis, chemo-sensitivity, and chemo-resistance of gastric cancer, as well as the stemness of gastric cancer stem cells. miR-708-3p induces gastric cancer cell chemo-resistance, but its actual role in gastric cancer progression remains unclear. This paper shows that miR-708-3p is upregulated in gastric cancer samples and that a high miR-708-3p expression in gastric cancer patients is associated with poor overall survival. Our functional study results indicate that miR-708-3p overexpression promotes gastric cancer cell proliferation and migration, inhibits cell apoptosis, and facilitates the transition from the G0/G1 to the G2/M phase. Furthermore, reducing miR-708-3p levels yielded opposite effects. Next, our in vivo experiments revealed that miR-708-3p advanced gastric cancer cell growth in nude mice. The underlying mechanism was the regulation of ethanolamine kinase 1 (ETNK1) expression by miR-708-3p, which bound to the 3'UTR of the ETNK1 gene in gastric cancer cells. Finally, the recovery assay results showed that ETNK1 overexpression could slow miR-708-3p-induced gastric cancer progression. In conclusion, we identified a new miR-708-3p/ETNK1 pathway involved in gastric cancer progression. These results may offer new targets for gastric cancer therapy and markers for gastric cancer prognosis.

Molecular Pathogenesis of BCR-ABL-Negative Atypical Chronic Myeloid Leukemia

Atypical chronic myeloid leukemia is a rare disease whose pathogenesis has long been debated. It currently belongs to the group of myelodysplastic/myeloproliferative disorders. In this review, an overview on the current knowledge about diagnosis, prognosis, and genetics is presented, with a major focus on the recent molecular findings. We describe here the molecular pathogenesis of the disease, focusing on the mechanisms of action of the main mutations as well as on gene expression profiling. We also present the treatment options focusing on emerging targeted therapies.

Impact of ETNK1 somatic mutations on phosphoethanolamine synthesis, ROS production and DNA damage

Recently we showed that Ethanolamine Kinase 1 (ETNK1) mutations cause a decreased synthesis of phosphoethanolamine, and that phosphoethanolamine is able to modulate mitochondrial activity through competition with succinate for complex II. The decreased phosphoethanolamine concentration leads to increased mitochondria activity and reactive oxygen species production, which causes the accumulation of new mutations.

miR-199a-3p targets ETNK1 to promote invasion and migration in gastric cancer cells and is associated with poor prognosis

PURPOSE

To investigate the prognostic significance of miR-199a-3p and its role in invasion and metastasis in gastric cancer.

METHODS

miR-199a-3p expression in 436 formalin-fixed and 39 frozen gastric cancer tissues was investigated by in situ hybridization and RT-PCR, respectively. The role of miR-199a-3p in the migration and invasion of gastric cancer cells was determined in overexpression and inhibitor studies using transwell assays and the SGC-7901, BGC-823 and MGC-803 gastric cancer cells lines. The effect of miR-199a-3p expression on ethanolamine kinase 1 (ETNK1) levels was determined by western botting.

RESULTS

miR-199a-3p was significantly up-regulated in AGS, SGC-7901, BGC-823 and MGC-803 gastric cancer cells, when compared with GES-1 non-malignant gastric epithelial cells. In situ hybridization studies revealed that human non-tumor gastric mucosa samples were negative for miR-199a-3p expression, while 162 of 436 (37.16%) cases of gastric cancer demonstrated positive expression. miR-199a-3p overexpression was associated with tumor size, Lauren classification, depth of invasion, lymph node and distant metastasis, TNM stage and prognosis. In patients with I, II and III stage tumors, high miR-199a-3p expression was associated with a significantly lower 5-year survival rate. miR-199a-3p overexpression was associated with increased cell migration and invasion. ETNK1 expression was inhibited following miR-199a-3p overexpression in BGC-823 and SGC-7901 cells, and elevated following miR-199a-3p suppression in MGC-803 cells.

CONCLUSION

miR-199a-3p is highly expressed in gastric cancer, and correlates with invasion, metastasis and prognosis. miR-199a-3p regulates the invasion and migration of gastric cancer cells by targeting ETNK1. Consequently, miR-199a-3p may serve as a prognostic indicator in gastric cancer.