AM251 International Journal of Pharmaceutics br Conclusions
International Journal of Pharmaceutics 568 (2019) 118511
Herein we reported a non-covalent conjugation approach between AT11 and AT11-B0 G4 and acridine orange derivatives in order to promote their selective delivery into HeLa cervical cancer cells. The resulting complexes were studied by circular dichroism, UV and fluor-escence spectroscopies. The serum AM251 of the complexes versus free DNA was also determined. Additionally, the aptamers and their con-jugates were tested in a cellular environment to assess their nucleolin binding potential, cell penetration ability and cytotoxic eﬀect against HeLa cancer and healthy cells. The results showed that the interaction of the acridine derivatives with the aptamers is characterized by a medium-high aﬃnity (KD values in the 10−6–10−7 M range), leading to the stabilization of their G4 structure (> 10 °C for all ligands). The formation of supramolecular complexes reduced the cytotoxicity of the free ligands towards non-malignant cells. Additionally, both AT11 and AT11-B0 seemed to bind nucleolin on the cell surface of HeLa cells, as suggested by the colocalization experiments using anti-nucleolin anti-body.
In summary, the complexes AT11 G4-C3, AT11 G4-C5, AT11-B0 G4-C3 and AT11-B0 G4-C5 seem more promising candidates as therapeutic tools for cervical cancer than the C8 congeners. Eventually, this trend might reflect the highest stability of the complexes AT11 G4-C8 and AT11-B0 G4-C8 that can hinder the intracellular release of C8 to exert its therapeutic action. Our results emphasize the potential of using G4-aptamers as drug delivery systems for cervical cancer.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influ-ence the work reported in this paper.
J. Carvalho acknowledges a doctoral fellowship grant from the FCT
Appendix A. Supplementary data
J. Figueiredo, et al.
development of the G-rich oligonucleotide AS1411 as a novel treatment for cancer.
specific binding to targets in cancer cells. J. Biomed. Biotechnol. 2010. https://doi.
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Aspirin inhibits hypoxia-mediated lung cancer cell stemness and exosome T function
Jinghua Chena,b, Ruilian Xub, Junxian Xiab, Jiacheng Huangb, Binbin Suc, Senming Wanga,
a Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510282, China b Department of Medical Oncology, Second Clinical Medicine College of Jinan University, Shenzhen People’s Hospital, Shenzhen 518020, China c Department of Gastroenterology, South Building, Chinese PLA General Hospital, Beijing 100853, China
Background: Epidemiological studies have illustrated that regular aspirin consumption may decrease the risk of non-small cell lung cancer (NSCLC). The present study aims to investigate the mechanism of aspirin-induced inhibition of NSCLC development during hypoxia. Methods: A549 cells were pre-treated with the vehicle control or aspirin and then subjected to hypoxic culture. Cell viability was monitored by CCK-8 assay, and flow cytometry was performed to detect cell cycle distribu-tions, apoptosis, and proportion of cancer stem cells (CSCs). Flow cytometric cell sorting was used to separate CSCs. Quantitative reverse transcription–polymerase chain reaction and Western blot were used to detect the mRNA and protein levels of stem cell markers and the related signaling molecules. The abundance of pros-taglandin E2 was detected by enzyme-linked immunosorbent assay. Exosomes in the cell culture medium were isolated using ExoQuick, and the number of exosomes was quantified by the EXOCET exosome quantification assay kit. Cell migration and angiogenesis were monitored by transwell migration assay and in vitro angiogenesis experiments.
Results: Aspirin inhibited cell proliferation and induced G2/M cell cycle arrest in hypoxic A549 cells; it also inhibited hypoxia-enhanced stemness in both A549 and ALDH+ cells. The drug reduced hypoxia-enhanced numbers of exosomes in A549 cells and exerted negative effects on the hypoxia-mediated up-regulation of exosomal HIF-1α/COX-2 and expression of exosomal miR-135b and miR-210. While hypoxic-induced exosomes can promote the proliferation, migration, and angiogenesis of other A549 cells, aspirin can weaken this pro-motion by reducing the amount of exosome secreted and changing exosome contents. Conclusions: Aspirin inhibits the hypoxia-induced stemness, hypoxic-mediated exosome release, and malignant paracrine effects of A549 cells.