Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.12.2 (MEK)
 18,161 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of Epstein-Barr virus (EBV) in the pathogenesis of breast cancer has been of long-standing interest to the field. Breast epithelial cells can be infected by EBV through direct contact with EBV-bearing lymphoblastoid cells, and EBV infection has recently been shown to confer breast cancer cells an increased resistance to chemotherapeutic drugs. In this study, we established EBV-infected breast cancer MCF7 and BT474 cells and demonstrated that EBV infection promotes tumorigenic activity of breast cancer cells. Firstly, we showed that the EBV-infected MCF7-A and BT474-A cells exhibited increased anchorage-independent growth in soft agar. The increased colony formation capacity in soft agar was associated with increased expression and activation of HER2/HER3 signaling cascades, as evidenced by the findings that the treatment of HER2 antibody trastuzumab (Herceptin), phosphatidylinositol 3-kinase inhibitor, or MEK inhibitor completely abolished the tumorigenic capacity. In the EBV-infected breast cancer cells, the expression of EBV latency genes including EBNA1, EBER1, and BARF0 was detected. We next showed that BARF0 alone was sufficient to efficiently up-regulate HER2/HER3 expression and promoted tumorigenic activity in MCF7 and BT474 cells by the use of both overexpression and small interfering RNA knock-down. Collectively, we demonstrated that EBV-encoded BARF0 promotes the tumorigenic activity of breast cancer cells through activation of HER2/HER3 signaling cascades.
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PMID:Dysregulation of HER2/HER3 signaling axis in Epstein-Barr virus-infected breast carcinoma cells. 1737 31

MKK4 is a candidate tumor suppressor, which acts as a critical mediator of Epstein-Barr Virus (EBV)-induced c-Jun N-terminal kinase (JNK) activation. Functional polymorphism MKK4 -1304T>G has been showed to be protective in colorectal cancer or lung cancer. We hypothesized that genetic variants in the MKK4 promoter were associated with the risk of nasopharyngeal carcinoma (NPC). Two common polymorphisms in MKK4, -1304T>G and -1044A>T were genotyped in two independent case-control panels of Eastern and Southern Chinese populations, totally containing 1237 NPC and 1328 controls. We found that compared to the most common -1304TT genotype, carriers of variant genotypes (-1304TG+GG) were associated with a significantly reduced risk for NPC in total subjects (adjusted OR = 0.78; 95%CI = 0.67-0.94). Further stratification analysis showed that the protective effect was more pronounced in EBV negative status (adjusted OR = 0.51; 95%CI = 0.41-0.68) but restrained in those with EBV infection (adjusted OR = 1.05; 95%CI = 0.88-1.26), and that the -1304GG variant genotypes interacted with EBV negative status on reducing cancer risk (p = 0.011). However, no significant association was observed between the -1044A>T polymorphism and risk of NPC. Our data suggest that the protective role of genetic variant MKK4 -1304T>G is restrained in NPC with EBV infection. These findings implicate the role of EBV and MKK4 -1304 T>G interaction as a causative factor for the NPC.
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PMID:The protective role of polymorphism MKK4-1304 T>G in nasopharyngeal carcinoma is modulated by Epstein-Barr virus' infection status. 2170 39