在EBV相关的胃癌（EBVaGC）中，内含于BART区域的EBV编码的miRNAs广泛表达，暗示它们在肿瘤发生中发挥作用。然而，这些病毒miRNAs如何促进EBVaGC的发展仍然十分模糊。在本研究中，我们发现EBV编码的miR-BART11-3p靶向双特异性磷酸酶6（DUSP6）mRNA的3'-UTR区域，上调ERK磷酸化并下调JNK和p38磷酸化。通过这种方式，miR-BART11-3p促进了胃癌（GC）细胞体外增殖、迁移和侵袭，并促进了体内肿瘤的生长。恢复DUSP6表达能够逆转miR-BART11-3p在AGS GC细胞中的肿瘤促进活性。一致地，DUSP6的沉默消除了miR-BART11-3p抑制剂在EBV阳性GC细胞中的抗肿瘤作用。此外，使用曲妥珠单抗阻断ERK磷酸化可抑制miR-BART11-3p表达的AGS细胞的增殖、迁移和侵袭。给予miR-BART11-3p抗反义寡核苷酸能够减少EBV阳性异种移植瘤的生长。综上所述，这些发现揭示了一种EBV编码的微小RNA通过调节MAPK途径来促进EBVaGC的发展与进展的新机制，可用于开发治疗EBVaGC的新疗法。【重要性】艾普斯坦-巴尔病毒（EBV）是发现编码miRNA的首个人类肿瘤病毒，BART区域的miRNA在EBVaGC中丰富表达并在促进肿瘤发生过程中发挥各种作用。在我们的研究中，我们观察到EBV-miR-BART11-3p促进细胞增殖，并引起GC的迁移和侵袭。有趣的是，我们发现miR-BART11-3p通过直接靶向双特异性磷酸酶6（DUSP6）的3'-UTR区域上调了P-ERK并下调了P-JNK和P-p38。恢复DUSP6能够解救miR-BART11-3p在GC细胞中产生的效应，使用Trametinib阻断ERK磷酸化增强了JNK和P-p38的磷酸化并抑制了miR-BART11-3p表达的AGS细胞的效应。这些结果表明，miR-BART11-3p通过调节DUSP6-MAPK通路促进了细胞的增殖、迁移和侵袭，从而提供了新的机制解释EBVaGC的肿瘤发生，并为开发针对miR-BART11-3p或磷酸化ERK的治疗策略提供了新的途径。

Epstein-Barr virus (EBV)-encoded miRNAs within the BamHI-A rightward transcript (BART) region are abundantly expressed in EBV-associated gastric cancer (EBVaGC), suggesting that they play roles in tumorigenesis. However, how these viral miRNAs contribute to the development of EBVaGC remains largely obscure. In this study, we found that EBV-encoded miR-BART11-3p targets 3' -UTR of dual-specificity phosphatase 6 (DUSP6) mRNA to upregulate ERK phosphorylation and downregulate JNK and p38 phosphorylation. By doing so, miR-BART11-3p promotes gastric cancer (GC) cell proliferation, migration, and invasion in vitro, and facilitates tumor growth in vivo. Restoration of DUSP6 expression reverses the tumor-promoting activity of miR-BART11-3p in AGS GC cells. Consistently, knockdown of DUSP6 ablates the antitumor effects of miR-BART11-3p inhibitors in EBV-positive GC cells. Furthermore, blocking ERK phosphorylation with trametinib inhibited the proliferation, migration, and invasion of miR-BART11-3p-expressing AGS cells. Administration of a miR-BART11-3p antagomir reduced the growth of EBV-positive xenograft tumors. Together, these findings reveal a novel mechanism by which EBV dysregulates MAPK pathways through an EBV-encoded microRNA to promote the development and progression of EBVaGC, which may be harnessed to develop new therapeutics to treat EBVaGC. IMPORTANCE The Epstein-Barr virus (EBV) is the first human tumor virus found to encode miRNAs, which within the BART region have been detected abundantly in EBV-associated gastric cancer (EBVaGC) and play various roles in promoting tumorigenesis. In our study, we observed that EBV-miR-BART11-3p promotes cell proliferation and induces migration and invasion in GC. Interestingly, we showed that miR-BART11-3p upregulates p-ERK and downregulates p-JNK and p-p38 by directly targeting 3'-UTR of dual-specificity phosphatase 6 (DUSP6). Restoration of DUSP6 rescues the effects generated by miR-BART11-3p in GC cells, and blocking ERK phosphorylation with Trametinib augments JNK and p38 phosphorylation and inhibits the effects of miR-BART11-3p-expressing AGS cells, suggesting that miR-BART11-3p promotes cell proliferation, migration, and invasion by modulating DUSP6-MAPK axis in EBVaGC. The findings presented in this study provide new mechanisms into the tumorigenesis in EBVaGC and new avenues for the development of therapeutic strategies to combat EBVaGC targeting miR-BART11-3p or phospho-ERK.