Taken together, the present study for the first time demonstrates that DANCR, acting as an oncogene in NPC, promotes NPC progression by interacting with STAT3 and enhancing JAK1 binding to STAT3 to strengthen IL-6/JAK1/STAT3 signaling, suggesting that it may be a potential target to be used as a novel strategy to develop NPC therapeutics.
Our data indicated that OIP5 was highly expressed in NPC and promoted NPC progression by modulating JAK2/STAT3; our results shed light on utilizing OIP5 as a potential novel therapeutic target for the treatment of NPC.
Our results demonstrated the anticancer efficacy of Ova in NPC and its potential as a putative inhibitor of JAK2 and STAT3, which are essential in tumorigenesis of NPC.
MiR-29a down-regulation is correlated with drug resistance of nasopharyngeal carcinoma cell line CNE-1 and MiR-29a up-regulation decreases Taxol resistance of nasopharyngeal carcinoma CNE-1 cells possibly via inhibiting STAT3 and Bcl-2 expression.
Interplay of DNA methyltransferase 1 and EZH2 through inactivation of Stat3 contributes to β-elemene-inhibited growth of nasopharyngeal carcinoma cells.
These findings illustrate miR-98 as a anticarcinogenic functions through targeting STAT3, the miR-98/STAT3 pathway gives new clues for understanding NPC carcinogenesis and provides novel therapeutic targetsfor NPC.
Protein levels of the signal transducers and activators of transcription 3 (STAT3), phospho-STAT3 (p-STAT3), mouse anti-human cyclin D2 (CCND2) and matrix metalloproteinase-2 (MMP-2) were tested by western blotting. miRNA-124-3p expression in NPC was markedly downregulated compared to postnasal catarrh tissues (P<0.001); miRNA-124-3p expression showed close linkage with clinical stages, regional lymph node involvement and T stages (all P<0.001). miRNA-124-3p expression was lower in the 7 NPC cell lines than NP69 cells (all P<0.05).
Our results demonstrated that STAT3 pathway plays an important role in mediating tumor-initiating capacities in NPC and suggest that inactivation of STAT3 with EGCG may represent a potential preventive and therapeutic approach for NPC.
Both in vitro and in vivo assays revealed that miR-21 enhanced NPC cell proliferation and suppressed apoptosis. miR-21, activated by STAT3, induced proliferation and suppressed apoptosis in NPC by targeting PTEN-AKT pathway.
Furthermore, IL-6R overexpression enhanced IL-6-induced STAT3 activation in uninfected immortalized NPE cells in vitro, and promoted growth and tumorigenicity of EBV-positive NPC cell line (C666-1) in vivo.
Lastly, the potential involvement of STAT3 in other oncovirus-associated (e.g. the human papillomavirus) head and neck cancers have not been investigated and we hope that findings in EBV-associated NPC can prompt future investigations in these cancers, which are of increasing impact in the Western countries.
Our previous study demonstrated that the nuclear EGFR could bind to the cyclin D1 promoter directly in the presence of LMP1, and the correlation between EGFR and STAT3 in NPC remains to be further explored.
EGFR and phosphorylated STAT3 were strongly expressed in cancer cells of NPC patients, but NF-kappaB was not expressed, suggesting that STAT3-dependent mechanism is important for NPC carcinogenesis.
Exogenous IL-6 was able to induce expression of LMP1 by means of STAT3 activation both in rEBV-infected carcinoma cell lines and in the EBV-positive C666-1 NPC cell line.