ABSTRACT
Objective The radiotherapy resistance is one of important causes for nasopharyngeal carcinoma(NPC) treatment failure.Junctional adhesion molecule A(JAMA)is closely correlated with the tumor poor prognosis.Thus this experiment is to in vestigate the relationship between JAMA expression and the radiosensitivity of NPC.Methods To overexpress or interfere the JAMA expression in CNE2 and HONE1 cell lines.Then different doses of X-ray were adopted to conduct irradiation.The cell clone formation capacity and cellular apoptosis change were detected after 24 h.The role of JAMA in the NPC radiotherapy was understand.The related signal pathway protein in cell lines with different JAMA expression was detected by Western blot.Results The cell lines with low JAMA expression were more sensitive to radiotherapy:After low JAMA expression,the D0 value in the CNE2 cell line was decreased from 3.26 ±0.78 to 1.92 ± 0.23;the Dq value was decreased from 46.51 ± 4.27 to 32.12 ± 3.19.The radio therapy induced apoptosis was significantly increased in the cell lines with low JAMA expression,after low JAMA expressing,thcellular apoptosis was elevated from 6.9 ％ ± 0.9 ％ to 13.7 ％ ± 1.3 ％;the HONE1 cellular apoptosis was elevated from 6.5 ％ + 1.1 ％ to 12.3 ％ ± 1.7％;JAMA overexpression cell lines were significantly decreased.The preliminary mechanism research results showed that JAMA played the effect via Akt signal pathway.Conclusion This research results verifiy that JAMA expression level is closely correlated with the radiosensitivity of NPC cell line:JAMA can increase the radiotherapy resistance of NPC cell lines,which provides a new feasible research direction for NPC enhancing radiosensitivity.
ABSTRACT
Objective To identify the role of miR-124 in regulating the radiosensitivity and the epithelial-mesenchymal transition (EMT) of nasopharyngeal carcinoma (NPC). Methods Transient transfection of cells with miR-124 mimic or inhibitor was performed and wound-healing assay was used to investigate the role of miR-124 in the EMT of NPC. The apoptosis affected by miR-124 was also measured after irradiation , followed by investigating the cell proliferation by EdU assay. Finally , proteins of Akt and ERK associated with EMT and radiosensitivity, were measured by western blot. Results The migration index from NPC cell line indicated that miR-124 repressed the EMT. The results from caspase-3 activity assay showed that caspase-3 activity after irradiation significantly increased in miR-124 mimic group compared with the control group (P < 0.01). It was also confirmed that irradiation led to a higher percentage of apoptosis in miR-124 group compared with the control group in NPC cells. Cell proliferation after irradiation was significantly decreased in MiR-124 group as compared with control group . MiR-124 inhibited the protein expression of p-Akt . Conclusion MiR-124 may repress the EMT and decrease radio-resistance of NPC via p-Akt signaling pathway , which may provide a new insight into radio-resistance in NPC.