Knockdown of eukaryotic translation initiation factor 4E suppresses cell growth and invasion, and induces apoptosis and cell cycle arrest in a human lung adenocarcinoma cell line

Update on the Development of MNK Inhibitors as Therapeutic Agents

Mitogen-activated protein kinase-interacting kinases 1 and 2 (MNK1/2) represent a central class of enzymes that are activated by extracellular signal-regulated kinase (ERK) or p38 mitogen-activated protein (MAP) kinases. MNK1 and MNK2 coordinate cellular signaling, control production of inflammatory chemokines, and regulate cell proliferation and survival. MNK1/2 are referred to as serine/threonine kinases as they phosphorylate serine or threonine residues on their substrates. Upon activation, MNK1/2 phosphorylate eukaryotic translation initiation factor 4E (eIF4E) at Ser209, which in turn initiates ribosome assembly and protein translation. Deleterious overexpression of MNK1/2 and/or eIF4E have been reported in several diseases including cancers, neurological disorders, autism, and inflammation. Recently, there have been intense efforts toward the development of potent and selective inhibitors of MNK1/2 in both academia and industry. Herein, we review the current understanding of the structural and biological aspects of MNK1/2 and provide an update of pharmacological inhibitors of MNK1/2 including candidates in clinical trials.

piR-651 and its function in 95-D lung cancer cells

PIWI-associated RNAs (piRNAs or piRs), a new-found class of small non-coding RNAs, which are mainly expressed in germline cells and partly in somatic lines, have a vital role in carcinogenesis by maintaining genomic integrity and regulation of epigenetics. The previous studies have confirmed that the expression of piR-651 is upregulated in several cancer tissue and cell lines, including lung cancer. However, the mechanism of carcinogenesis and piR-651 remains to be elucidated. Therefore, the present study assessed the 95-D high metastasis human lung cancer cell line to detect the effect of piR-651 on carcinogenesis. Firstly, piR-651 promoted the high metastasis characteristic of the 95-D cell lines by Transwell and wound-healing assays. The influence of piR-651 on tumor cell proliferation and apoptosis was detected by the MTT assay and flow cytometry. In conclusion, piR-651 may be an oncogene in lung cancer formation and development. Therefore, piR-651 regulated carcinogenesis by influencing cell proliferation, apoptosis, migration and invasion, and may be a potential tumor marker and therapeutic target.