title: X-Ray Psoralen Activated Cancer Therapy (X-PACT).
abstract: This work investigates X-PACT (X-ray Psoralen Activated Cancer Therapy): a new approach for the treatment of solid cancer. X-PACT utilizes psoralen, a potent anti-cancer therapeutic with current application to proliferative disease and extracorporeal photopheresis (ECP) of cutaneous T Cell Lymphoma. An immunogenic role for light-activated psoralen has been reported, contributing to long-term clinical responses. Psoralen therapies have to-date been limited to superficial or extracorporeal scenarios due to the requirement for psoralen activation by UVA light, which has limited penetration in tissue. X-PACT solves this challenge by activating psoralen with UV light emitted from novel non-tethered phosphors (co-incubated with psoralen) that absorb x-rays and re-radiate (phosphoresce) at UV wavelengths. The efficacy of X-PACT was evaluated in both in-vitro and in-vivo settings. In-vitro studies utilized breast (4T1), glioma (CT2A) and sarcoma (KP-B) cell lines. Cells were exposed to X-PACT treatments where the concentrations of drug (psoralen and phosphor) and radiation parameters (energy, dose, and dose rate) were varied. Efficacy was evaluated primarily using flow cell cytometry in combination with complimentary assays, and the in-vivo mouse study. In an in-vitro study, we show that X-PACT induces significant tumor cell apoptosis and cytotoxicity, unlike psoralen or phosphor alone (p<0.0001). We also show that apoptosis increases as doses of phosphor, psoralen, or radiation increase. Finally, in an in-vivo pilot study of BALBc mice with syngeneic 4T1 tumors, we show that the rate of tumor growth is slower with X-PACT than with saline or AMT + X-ray (p<0.0001). Overall these studies demonstrate a potential therapeutic effect for X-PACT, and provide a foundation and rationale for future studies. In summary, X-PACT represents a novel treatment approach in which well-tolerated low doses of x-ray radiation are delivered to a specific tumor site to generate UVA light which in-turn unleashes both short- and potentially long-term antitumor activity of photo-active therapeutics like psoralen.
authors: Dept. of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Mark
authors: M
authors: Oldham
authors: Dept. of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Paul
authors: P
authors: Yoon
authors: Immunolight LLC, Detroit, Michigan, United States of America.
authors: Zak
authors: Z
authors: Fathi
authors: QNS Group, LLC, Bahama, North Carolina, United States of America.
authors: Wayne F
authors: WF
authors: Beyer
authors: Dept. of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Justus
authors: J
authors: Adamson
authors: Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Leihua
authors: L
authors: Liu
authors: Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: David
authors: D
authors: Alcorta
authors: Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Wenle
authors: W
authors: Xia
authors: Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Takuya
authors: T
authors: Osada
authors: Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Congxiao
authors: C
authors: Liu
authors: Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Xiao Y
authors: XY
authors: Yang
authors: Dept. of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Rebecca D
authors: RD
authors: Dodd
authors: Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: James E
authors: JE
authors: Herndon
authors: Dept. of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Boyu
authors: B
authors: Meng
authors: Dept. of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: David G
authors: DG
authors: Kirsch
authors: Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: H Kim
authors: HK
authors: Lyerly
authors: Dept. of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Mark W
authors: MW
authors: Dewhirst
authors: Department of Neurosurgery, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Peter
authors: P
authors: Fecci
authors: Dept. of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Harold
authors: H
authors: Walder
authors: Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America.
authors: Neil L
authors: NL
authors: Spector
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic; D004307:Dose-Response Relationship, Radiation; D005363:Ficusin / Q000494:pharmacology* / Q000627:therapeutic use; D051379:Mice; D009369:Neoplasms / Q000532:radiotherapy*; D014964:X-Ray Therapy / Q000379:methods*
chemical_list: D005363:Ficusin