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Nasopharyngeal carcinoma (NPC) is a unique subtype of head and neck cancer that is endemic to Southern China and Southeast Asia. Due to the concealed location and intrinsic invasiveness of this disease, majority of NPC patients are diagnosed with advanced stages (III and IV) and poor prognosis. Chemoradiotherapy resistance is a major problem for NPC patients, leading to incomplete local elimination, recurrence and metastasis. Therefore, it is of great significance to seek novel biomarkers and effective therapeutic regimen for clinical management of this deadly cancer. Exosomes are tiny membrane vesicles with a lipid bilayer secreted by most cells in the body, which are widely distributed in various body fluids. They are functionally active in different physiopathological process by carrying and transmitting important signal molecules such as miRNA, mRNA, protein, lipid, etc. Exosomal miRNAs play an important role in tumorigenesis and development of NPC. They are extensively involved in NPC cell proliferation, migration, invasion, neovascularization, radiotherapy resistance and the regulation of tumor immune microenvironment through intercellular communication and control of gene expression. Moreover, exosomal miRNAs can be used as valuable biomarkers for early diagnosis and therapeutic targets of NPC., Competing Interests: None., (AJCR Copyright © 2021.)

Resisting cell death is one of the hallmarks of cancer. Necroptosis is a form of non-caspase dependent necrotic cell death mediated by receptor-interacting protein kinase-1/3 (RIP1/3), which represents another mode of programmed cell death besides apoptosis. RIP3 also acts as an energy metabolism regulator associated with switching cell death from apoptosis to necroptosis. Trichothecin (TCN) is a sesquiterpenoid originating from endophytic fungi and shows potent anti-tumor bioactivity. Our current findings reveal that RIP3 mediates TCN-induced necroptosis through up-regulating PYGL and PDC-E1α to promote mitochondria energy metabolism and ROS production. RIP3 might be involved in sensitizing tumor cells to chemotherapy induced by TCN. Therefore, activating RIP3 to initiate necroptosis contributes to the bioactivity of TCN. Moreover, TCN could be exploited for therapeutic gain through up-regulating RIP3 to sensitize cancer chemotherapy., Competing Interests: None., (AJCR Copyright © 2021.)

Anoikis resistance is an important mechanism that mediates tumor metastasis. Studies have found that Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) promotes the occurrence, development, and metastasis of nasopharyngeal carcinoma (NPC). However, the related mechanism, especially whether LMP1 is involved in NPC metastasis through anoikis resistance, has not yet been elucidated. In present study, we showed that LMP1 enhanced the ability of NPC cells to resist anoikis by upregulating neurotrophic tyrosine kinase receptor type 2 (NTRK2 or TrkB) expression through NF-κB signaling and promoted the migration and invasion of NPC cells. After knockdown of NTRK2, the p-ERK and p-AKT in NPC cells were inhibited, and twist expression was further reduced, resulting in upregulation of E-cadherin expression and downregulation of vimentin expression. Subsequently, the results of a xenograft experiment showed that inhibiting NTRK2 could reduce LMP1-mediated NPC metastasis in vivo. In summary, these findings demonstrated that EBV-LMP1 upregulates twist expression to promote epithelial-mesenchymal transition (EMT) through the NTRK2-mediated AKT/ERK signaling pathway, thus mediating anoikis resistance and promoting NPC metastasis. These data will provide new molecular markers and potential targets for NPC metastasis., Competing Interests: None., (AJCR Copyright © 2020.)

Vasculogenic mimicry (VM) is a brand-new tumor vascular pattern with the ability to form vessel-like networks without participation of endothelial cells and independent on angiogenesis. It can provide adequate blood supply for tumor growth. The formation of VM involves multiple molecule mechanisms and signal pathways, including cancer stem cell and epithelial-mesenchymal transition. As a unique blood-supply pattern, VM is associated with cancer invasion, metastasis and poor prognosis. Because of its important role in cancer progression, VM will become a new target for therapy of cancers.