Several studies have shown that gallic acid (GA) induces apoptosis in different cancer cell lines, whereas the mechanism of action of GA-induced apoptosis at the molecular level in human non-small-cell lung cancer NCI-H460 cells is not well-known. Here, GA decreasing the percentage of viable NCI-H460 cells was investigated; GA-induced apoptosis involved G2/M phase arrest and intracellular Ca(2+) production, the loss of mitochondrial membrane potential (DeltaPsi(m)), and caspase-3 activation. The efficacious induction of apoptosis and DNA damage was observed at 50-500 microM for 24 and/or 48 h as examined by flow cytometry, DAPI staining, and Comet assay methods. Western blotting and flow cytometric analysis also demonstrated that GA increased protein levels of GADD153 and GRP78, activation of caspase-8, -9, and -3, loss of DeltaPsi(m) and cytochrome c, and AIF release from mitochondria. Moreover, apoptosome formation and activation of caspase cascade were associated with apoptotic cell death. GA increased Bax and Bad protein levels and decreased Bcl-2 and Bcl-xL levels. GA may also induce apoptosis through a caspase-independent AIF pathway. In nude mice bearing NCI-H460 xenograft tumors, GA inhibited tumor growth in vivo. The data suggest that GA induced apoptosis in NCI-H460 lung cancer cells via a caspase-3 and mitochondrion-dependent pathway and inhibited the in vivo tumor growth of NCI-H460 cells in xenograft models.

Exosomes mediate cell-cell crosstalk in cancer progression by transferring their molecular cargos, including long noncoding RNAs (lncRNAs). Metastasis‑associated lung adenocarcinoma transcript 1 (MALAT1) is a well-known lncRNA associated with cancer angiogenesis and metastasis. However, the presence of MALAT1 in exosomes and the roles and clinical values of exosomal MALAT1 in epithelial ovarian cancer (EOC) remain unknown. The present study focused on the crosstalk between EOC cells and endothelial cells mediated by exosomal MALAT1 and aimed to explore the roles of exosomes and exosomal MALAT1 in EOC angiogenesis and to reveal the clinical relevance and prognostic predictive value of serum exosomal MALAT1 in EOC. We observed that MALAT1 was increased in both metastatic EOC cells and their secreted exosomes. Exosomal MALAT1 derived from EOC cells was transferred to recipient human umbilical vein endothelial cells (HUVECs) via exosomes. In vitro and in vivo experiments demonstrated that MALAT1 knockdown impaired the exosome-mediated proangiogenic activity of HUVECs through certain key angiogenesis-related genes. Clinically, elevated serum exosomal MALAT1 was highly correlated with an advanced and metastatic phenotype of EOC and was an independent predictive factor for EOC overall survival (OS). Moreover, a prognostic nomogram model we constructed showed a good prediction of the probability of 3-year OS of EOC patients according to the c-index (0.751, 95% confidence interval [CI]=0.691-0.811) and calibration curve. Collectively, our data provide a novel mechanism by which EOC cells transfer MALAT1 via exosomes to recipient HUVECs and influence HUVECs by stimulating angiogenesis-related gene expression, eventually promoting angiogenesis. Additionally, circulating exosomal MALAT1 can serve as a promising serum-based, noninvasive predictive biomarker for EOC prognosis.

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Objective: The transfer of long noncoding RNAs (lncRNAs) via exosomes to modulate recipient cells represents an important mechanism for disease progression. Antisense hypoxia-inducible factor (aHIF) is a well-known angiogenesis-related lncRNA. Here, we aimed to investigate the clinical implications of aHIF and exosomal aHIF in endometriosis and the involvement of exosome-shuttled aHIF in endometriosis angiogenesis. Study Design: The distribution and expression of aHIF in ectopic, eutopic, and normal endometria was evaluated. Serum exosomal aHIF levels in patients with endometriosis were tested. The correlation between serum exosomal aHIF and aHIF expression in ectopic endometria was analyzed. Endometriotic cyst stromal cells (ECSCs)-derived exosomes were characterized. The internalization of exosomes by human umbilical vein endothelial cells (HUVECs) was observed. A series of in vitro assays were conducted to investigate the roles and mechanisms of exosomal aHIF in endometriosis angiogenesis. Results: Clinically, aHIF was highly expressed in ectopic endometria and serum exosomes in patients with endometriosis. Serum exosomal aHIF was significantly correlated to aHIF expression in matched ectopic endometria. In vitro, PKH67-labeled exosomes derived from aHIF high expression ECSCs were effectively internalized by recipient HUVECs. Notably, exosome-shuttled aHIF was transferred from ECSCs to HUVECs, which in turn elicited proangiogenic behavior in HUVECs by activating vascular endothelial growth factor (VEGF)-A, VEGF-D, and basic fibroblast growth factor, thereby facilitating endometriosis angiogenesis. Conclusion: Our study illustrates a potential cell–cell communication between ECSCs and HUVECs in an ectopic environment, provides a novel mechanistic model explaining how ECSCs induce angiogenesis from the perspective of the “exosomal transfer of aHIF,” and highlights the clinical value of circulating exosomal aHIF in endometriosis.