RESUMO
Esophageal squamous cell carcinoma (ESCC) is one of most prevalent cancers worldwide, especially in China. Lacking in depth mechanism study, effective targets and therapeutics are desperately needed in the clinic. RNA-binding proteins (RBPs) mediate the localization, stability, and translation of the target transcripts and fine-tune the physiological functions of the proteins encoded. Bioinformatics analysis revealed that IGF2BPs were highly expressed in ESCC tissues and at least participated in the regulation of cell proliferation of ESCC cells. Biological researches demonstrated that IGF2BP2 promoted the cell proliferation, migration and invasion of ESCC KYSE30 and KYSE450 cells. IGF2BP2 could bind to EIF4A1 mRNA by recognition of m6A sites and enhanced translation of EIF4A1. IGF2BPs, as m6A reader, IGF2BPs were oncogenic genes in ESCC by regulating the expression of EIF4A1 through m6A sites. IGF2BP2, EIF4A1 and their targets could serve as potential biomarkers and therapeutic targets for ESCC, offering promising novel approaches for the diagnosis and treatment of ESCC.
RESUMO
Laryngeal squamous cell carcinoma (LSCC) is the major type of laryngeal carcinoma. SHIP2 plays a critical role in malignant tumors and is associated with activation of PI3K/Akt signaling pathway. Here, we aimed to explore the impacts of SHIP2 on LSCC Hep-2 cells and the relationship between SHIP2 and radiotherapy. SHIP2 knockdown impairs cell proliferation, invasion, migration and promotes cell apoptosis in this study, suggesting the oncogenic role of SHIP2 in laryngeal cancer. Radiation not only has the similar effect on laryngeal cancer as SHIP2 knockdown, but also causes significant cell cycle G2 arrest, all of which can be significantly enhanced by SHIP2 knockdown. This enhancement effect cause by SHIP2 knockdown derive from the inactivation of PI3K/Akt signaling pathway along with its downstream proteins. Our finding revealed a novel mechanism for sensitivity to radiotherapy caused by SHIP2 knockdown that called descending-SHIP2-mediated radiosensitivity enhancement (DSMRSE).
Assuntos
Carcinoma de Células Escamosas/metabolismo , Neoplasias Laríngeas/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Tolerância a Radiação , Apoptose , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Movimento Celular , Humanos , Neoplasias Laríngeas/patologia , Invasividade Neoplásica , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Transdução de SinaisRESUMO
PURPOSE: To investigate the impact of autophagy on the low-dose hyper-radiosensitivity (HRS) of human lung adenocarcinoma cells via MLH1 regulation. MATERIALS AND METHODS: Immunofluorescent staining, Western blotting, and electron microscopy were utilized to detect autophagy in A549 and H460 cells. shRNA was used to silence MLH1 expression. The levels of MLH1, mTOR, p-mTOR, BNIP3, and Beclin-1 were measured by real-time polymerase chain reaction (PCR) and Western blotting. RESULTS: A549 cells, which have low levels of MLH1 expression, displayed HRS/induced radioresistance (IRR). Conversely, the radiosensitivity of H460 cells, which express high levels of MLH1, conformed to the linear-quadratic (LQ) model. After down-regulating MLH1 expression, A549 cells showed increased HRS and inhibition of autophagy, whereas H460 cells exhibited HRS/IRR. The levels of mTOR, p-mTOR, and BNIP3 were reduced in cells harboring MLH1 shRNA, and the changes in the mTOR/p-mTOR ratio mirrored those in MLH1 expression. CONCLUSIONS: Low MLH1-expressing A549 cells may exhibit HRS. Both the mTOR/p-mTOR and BNIP3/Beclin-1 signaling pathways were found to be related to HRS, but only mTOR/p-mTOR is involved in the regulation of HRS via MLH1 and autophagy.
