title: The anti-angiogenic and cytotoxic effects of the boswellic acid analog BA145 are potentiated by autophagy inhibitors.
abstract: BACKGROUND
  While angiogenesis inhibitors represent a viable cancer therapy, there is preclinical and clinical data to suggest that many tumors develop resistance to such treatments. Moreover, previous studies have revealed a complex association between autophagy and angiogenesis, and their collective influence on tumorigenesis. Autophagy has been implicated in cytoprotection and tumor promotion, and as such may represent an alternative way of targeting apoptosis-resistant cancer cells. This study explored the anti-cancer agent and boswellic acid analog BA145 as an inducer of autophagy and angiogenesis-mediated cytoprotection of tumor cells.
  
  
  METHODS
  Flow cytometry, western blotting, and confocal microscopy were used to investigate the role of BA145 mediated autophagy. ELISA, microvessel sprouting, capillary structure formation, aortic ring and wound healing assays were performed to determine the relationship between BA145 triggered autophagy and angiogenesis. Flow cytometery, western blotting, and microscopy were employed to examine the mechanism of BA145 induced cell death and apoptosis. Live imaging and tumor volume analysis were carried out to evaluate the effect of BA145 triggered autophagy on mouse tumor xenografts.
  
  
  RESULTS
  BA145 induced autophagy in PC-3 cancer cells and HUVECs significantly impeded its negative regulation on cell proliferation, migration, invasion and tube formation. These effects of BA145 induced autophagy were observed under both normoxic and hypoxic conditions. However, inhibition of autophagy using either pharmacological inhibitors or RNA interference enhanced the BA145 mediated death of these cells. Similar observations were noticed with sunitinib, the anti-angiogenic properties of which were significantly enhanced during combination treatments with autophagy inhibitors. In mouse tumor xenografts, co-treatment with chloroquinone and BA145 led to a considerable reduction in tumor burden and angiogenesis compared to BA145 alone.
  
  
  CONCLUSIONS
  These studies reveal the essential role of BA145 triggered autophagy in the regulation of angiogenesis and cytoprotection. It also suggests that the combination of the autophagy inhibitors with chemotherapy or anti-angiogenic agents may be an effective therapeutic approach against cancer.
authors.affiliation: Department of Cancer Pharmacology, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, 180001, India. pathaniaanup234@yahoo.co.in.|Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110001, India. pathaniaanup234@yahoo.co.in.
authors.forename: Anup S
authors.initials: AS
authors.lastname: Pathania
authors.affiliation: Department of Cancer Pharmacology, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, 180001, India. zahoorwani5@gmail.com.
authors.forename: Zahoor A
authors.initials: ZA
authors.lastname: Wani
authors.affiliation: Department of Cancer Pharmacology, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, 180001, India. santoshkumarguru@gmail.com.
authors.forename: Santosh K
authors.initials: SK
authors.lastname: Guru
authors.affiliation: Department of Cancer Pharmacology, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, 180001, India. surthakur86@gmail.com.|Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110001, India. surthakur86@gmail.com.
authors.forename: Suresh
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Department of Cancer Pharmacology, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, 180001, India. sbhushan@iiim.ac.in.
authors.forename: Shashi
authors.initials: S
authors.lastname: Bhushan
authors.affiliation: Department of Biochemistry and Molecular Biology, Georgia Regents University Cancer Center, 1410 Laney Walker Boulevard CN2136, Augusta, GA, 30912, USA. hkorkaya@gru.edu.
authors.forename: Hasan
authors.initials: H
authors.lastname: Korkaya
authors.affiliation: Department of Biology, Appalachian State University, 572 Rivers Street, Boone, NC, 28608, USA. sealsdf@appstate.edu.
authors.forename: Darren F
authors.initials: DF
authors.lastname: Seals
authors.affiliation: Department of Cancer Pharmacology, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, 180001, India. ajaykmahajan@hotmail.com.
authors.forename: Ajay
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Department of Cancer Pharmacology, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, 180001, India. dmmondhe@iiim.ac.in.
authors.forename: Dilip M
authors.initials: DM
authors.lastname: Mondhe
authors.affiliation: Department of Inflammation Pharmacology, Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, 180001, India. Zahmed@iiim.ac.in.
authors.forename: Zabeer
authors.initials: Z
authors.lastname: Ahmed
authors.affiliation: Department of Inflammation Pharmacology, Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, 180001, India. bkrishan@iiim.ac.in.
authors.forename: Bal K
authors.initials: BK
authors.lastname: Chandan
authors.affiliation: Department of Cancer Pharmacology, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, 180001, India. fmalik@iiim.ac.in.|Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110001, India. fmalik@iiim.ac.in.
authors.forename: Fayaz
authors.initials: F
authors.lastname: Malik
mesh_terms: D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001343:Autophagy / Q000187:drug effects*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D000077210:Sunitinib; D014315:Triterpenes / Q000737:chemistry*
chemical_list: D020533:Angiogenesis Inhibitors; D007211:Indoles; D011758:Pyrroles; D014315:Triterpenes; C054625:boswellic acid; D000077210:Sunitinib