Detailed Instructions: In this task, you are given an abstract of article. Your task is to generate label "True" if abstract is structured, otherwise generate "False". A structured abstract is composed of a topic sentence (or key sentence), relevant supporting sentences, and a closing (or transition) sentence. This structure is key to keeping your abstract focused on the main idea and creating a clear and concise image.
Q: BACKGROUND Exosomes are extracellular vesicles that mediate cellular communication in health and diseases. Neutrophils could be polarized to a pro-tumor phenotype by tumor. The function of tumor-derived exosomes in neutrophil regulation remains unclear.
METHODS We investigated the effects of gastric cancer cell-derived exosomes (GC-Ex) on the pro-tumor activation of neutrophils and elucidated the underlying mechanisms.
RESULTS GC-Ex prolonged neutrophil survival and induced expression of inflammatory factors in neutrophils. GC-Ex-activated neutrophils, in turn, promoted gastric cancer cell migration. GC-Ex transported high mobility group box-1 (HMGB1) that activated NF-B pathway through interaction with TLR4, resulting in an increased autophagic response in neutrophils. Blocking HMGB1/TLR4 interaction, NF-B pathway, and autophagy reversed GC-Ex-induced neutrophil activation. Silencing HMGB1 in gastric cancer cells confirmed HMGB1 as a key factor for GC-Ex-mediated neutrophil activation. Furthermore, HMGB1 expression was upregulated in gastric cancer tissues. Increased HMGB1 expression was associated with poor prognosis in patients with gastric cancer. Finally, gastric cancer tissue-derived exosomes acted similarly as exosomes derived from gastric cancer cell lines in neutrophil activation.
CONCLUSION We demonstrate that gastric cancer cell-derived exosomes induce autophagy and pro-tumor activation of neutrophils via HMGB1/TLR4/NF-B signaling, which provides new insights into mechanisms for neutrophil regulation in cancer and sheds lights on the multifaceted role of exosomes in reshaping tumor microenvironment.
A:
True