1
|
Seshacharyulu P, Baine MJ, Souchek JJ, Menning M, Kaur S, Yan Y, Ouellette MM, Jain M, Lin C, Batra SK. Biological determinants of radioresistance and their remediation in pancreatic cancer. Biochim Biophys Acta Rev Cancer 2017; 1868:69-92. [PMID: 28249796 PMCID: PMC5548591 DOI: 10.1016/j.bbcan.2017.02.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/16/2017] [Accepted: 02/17/2017] [Indexed: 12/17/2022]
Abstract
Despite recent advances in radiotherapy, a majority of patients diagnosed with pancreatic cancer (PC) do not achieve objective responses due to the existence of intrinsic and acquired radioresistance. Identification of molecular mechanisms that compromise the efficacy of radiation therapy and targeting these pathways is paramount for improving radiation response in PC patients. In this review, we have summarized molecular mechanisms associated with the radio-resistant phenotype of PC. Briefly, we discuss the reversible and irreversible biological consequences of radiotherapy, such as DNA damage and DNA repair, mechanisms of cancer cell survival and radiation-induced apoptosis following radiotherapy. We further describe various small molecule inhibitors and molecular targeting agents currently being tested in preclinical and clinical studies as potential radiosensitizers for PC. Notably, we draw attention towards the confounding effects of cancer stem cells, immune system, and the tumor microenvironment in the context of PC radioresistance and radiosensitization. Finally, we discuss the need for examining selective radioprotectors in light of the emerging evidence on radiation toxicity to non-target tissue associated with PC radiotherapy.
Collapse
Affiliation(s)
- Parthasarathy Seshacharyulu
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Michael J Baine
- Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Joshua J Souchek
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Melanie Menning
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Sukhwinder Kaur
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Ying Yan
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Michel M. Ouellette
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Maneesh Jain
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Chi Lin
- Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Surinder K. Batra
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| |
Collapse
|
2
|
A herpes-like virus in king crabs: Characterization and transmission under laboratory conditions. J Invertebr Pathol 2015; 127:21-31. [PMID: 25712900 DOI: 10.1016/j.jip.2015.02.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 01/30/2015] [Accepted: 02/12/2015] [Indexed: 11/23/2022]
Abstract
A herpes-like virus was found infecting the antennal gland and bladder epithelium in the blue king crab Paralithodes platypus from the eastern area of the Sea of Okhotsk. Electron microscopic analysis of antennal gland samples from blue king crabs with histologically confirmed signs of disease revealed virus particles, which were mostly hexagonal in shape and located primarily in the nucleus; these particles were rarely observed in the cytoplasm of infected cells. Most virus particles ranged in size from 115 to 125nm. Hemocytes of the red king crab Paralithodes camtschaticus in cell culture could be experimentally infected with virus from thawed antennal gland samples of the blue king crabs with histologically confirmed signs of viral infection. Clear signs of infection were observed in hemocyte cultures at 3-4days post-inoculation as small foci of highly vacuolated formations. These formations included several nuclei and were surrounded by a halo of small cytoplasmic bubbles containing actin and tubulin. As demonstrated by electron microscopic studies, no virus-like particles were found in the cells 1day post-inoculation, but particles become abundant at 7days post-inoculation. We developed a consensus primer PCR method for amplification of a region of the herpesviral DNA-directed DNA polymerase. Primers were designed to target sequences encoding highly conserved amino acid motifs covering a region of approximately 800bp. Thus, macroscopic, histological and ultra-structural examinations of blue king crabs infected with a virus and the molecular identification of the pathogen revealed the presence of herpesviruses. The frequency of the herpes-like viral infection in natural populations of blue king crabs in the Sea of Okhotsk ranged from 0% to 3% in different years.
Collapse
|
4
|
Goodhead DT. ELECTRON SPIN RESONANCE IDENTIFICATION OF MELANIN IN COMEDONES. Br J Dermatol 1970. [DOI: 10.1111/j.1365-2133.1970.tb15043.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|