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Ouellette MM, Zhou S, Yan Y. Cell Signaling Pathways That Promote Radioresistance of Cancer Cells. Diagnostics (Basel) 2022; 12:diagnostics12030656. [PMID: 35328212 PMCID: PMC8947583 DOI: 10.3390/diagnostics12030656] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/26/2022] [Accepted: 03/02/2022] [Indexed: 12/20/2022] Open
Abstract
Radiation therapy (RT) is a standard treatment for solid tumors and about 50% of patients with cancer, including pediatric cancer, receive RT. While RT has significantly improved the overall survival and quality of life of cancer patients, its efficacy has still been markedly limited by radioresistance in a significant number of cancer patients (intrinsic or acquired), resulting in failure of the RT control of the disease. Radiation eradicates cancer cells mainly by causing DNA damage. However, radiation also concomitantly activates multiple prosurvival signaling pathways, which include those mediated by ATM, ATR, AKT, ERK, and NF-κB that promote DNA damage checkpoint activation/DNA repair, autophagy induction, and/or inhibition of apoptosis. Furthermore, emerging data support the role of YAP signaling in promoting the intrinsic radioresistance of cancer cells, which occurs through its activation of the transcription of many essential genes that support cell survival, DNA repair, proliferation, and the stemness of cancer stem cells. Together, these signaling pathways protect cancer cells by reducing the magnitude of radiation-induced cytotoxicity and promoting radioresistance. Thus, targeting these prosurvival signaling pathways could potentially improve the radiosensitivity of cancer cells. In this review, we summarize the contribution of these pathways to the radioresistance of cancer cells.
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Affiliation(s)
- Michel M. Ouellette
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Sumin Zhou
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Ying Yan
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE 68198, USA;
- Correspondence:
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2
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Ouellette MM, Yan Y. Radiation‐activated prosurvival signaling pathways in cancer cells. PRECISION RADIATION ONCOLOGY 2019. [DOI: 10.1002/pro6.1076] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Michel M. Ouellette
- Department of Internal MedicineUniversity of Nebraska Medical Center Omaha Nebraska USA
| | - Ying Yan
- Department of Radiation OncologyUniversity of Nebraska Medical Center Omaha Nebraska USA
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3
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Smyth LM, Rogers PAW, Crosbie JC, Donoghue JF. Characterization of Diffuse Intrinsic Pontine Glioma Radiosensitivity using Synchrotron Microbeam Radiotherapy and Conventional Radiation Therapy In Vitro. Radiat Res 2018; 189:146-155. [PMID: 29364085 DOI: 10.1667/rr4633.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Synchrotron microbeam radiation therapy is a promising preclinical radiotherapy modality that has been proposed as an alternative to conventional radiation therapy for diseases such as diffuse intrinsic pontine glioma (DIPG), a devastating pediatric tumor of the brainstem. The primary goal of this study was to characterize and compare the radiosensitivity of two DIPG cell lines (SF7761 and JHH-DIPG-1) to microbeam and conventional radiation. We hypothesized that these DIPG cell lines would exhibit differential responses to each radiation modality. Single cell suspensions were exposed to microbeam (112, 250, 560, 1,180 Gy peak dose) or conventional (2, 4, 6 and 8 Gy) radiation to produce clonogenic cell-survival curves. Apoptosis induction and the cell cycle were also analyzed five days postirradiation using flow cytometry. JHH-DIPG-1 cells displayed greater radioresistance than SF7761 to both microbeam and conventional radiation, with higher colony formation and increased accumulation of G2/M-phase cells. Apoptosis was significantly increased in SF7761 cells compared to JHH-DIPG-1 after microbeam irradiation, demonstrating cell-line specific differential radiosensitivity to microbeam radiation. Additionally, biologically equivalent doses to microbeam and conventional radiation were calculated based on clonogenic survival, furthering our understanding of the response of cancer cells to these two radiotherapy modalities.
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Affiliation(s)
- L M Smyth
- a University of Melbourne, Department of Obstetrics and Gynaecology, Royal Women's Hospital, Parkville 3052, Australia.,b Epworth Radiation Oncology, Epworth HealthCare, Richmond 3121, Australia
| | - P A W Rogers
- a University of Melbourne, Department of Obstetrics and Gynaecology, Royal Women's Hospital, Parkville 3052, Australia
| | - J C Crosbie
- c School of Science, RMIT University, Melbourne 3001, Australia.,d William Buckland Radiotherapy Centre, Alfred Hospital, Melbourne 3004, Australia; and
| | - J F Donoghue
- a University of Melbourne, Department of Obstetrics and Gynaecology, Royal Women's Hospital, Parkville 3052, Australia.,c School of Science, RMIT University, Melbourne 3001, Australia.,e Hudson Institute of Medical Research, Monash University, Clayton 3168, Australia
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Falcão PL, Motta BM, de Lima FC, Lima CV, Campos TPR. Enhancement of viability of radiosensitive (PBMC) and resistant (MDA-MB-231) clones in low-dose-rate cobalt-60 radiation therapy. Radiol Bras 2015; 48:158-65. [PMID: 26185342 PMCID: PMC4492568 DOI: 10.1590/0100-3984.2014.0022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 11/10/2014] [Indexed: 12/01/2022] Open
Abstract
Objective In the present study, the authors investigated the in vitro
behavior of radio-resistant breast adenocarcinoma (MDA-MB-231) cells line and
radiosensitive peripheral blood mononuclear cells (PBMC), as a function of
different radiation doses, dose rates and postirradiation time kinetics, with a
view to the interest of clinical radiotherapy. Materials and Methods The cells were irradiated with Co-60, at 2 and 10 Gy and two different exposure
rates, 339.56 cGy.min–1 and the other corresponding to one fourth of
the standard dose rates, present over a 10-year period of cobalt therapy.
Post-irradiation sampling was performed at pre-established kinetics of 24, 48 and
72 hours. The optical density response in viability assay was evaluated and a
morphological analysis was performed. Results Radiosensitive PBMC showed decrease in viability at 2 Gy, and a more significant
decrease at 10 Gy for both dose rates. MDAMB- 231 cells presented viability
decrease only at higher dose and dose rate. The results showed MDA-MB-231 clone
expansion at low dose rate after 48–72 hours post-radiation. Conclusion Low dose rate shows a possible potential clinical impact involving decrease in
management of radio-resistant and radiosensitive tumor cell lines in cobalt
therapy for breast cancer.
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Affiliation(s)
- Patrícia Lima Falcão
- Postdoc, Associate Professor at Universidade Federal do Amazonas (UFAM), Manaus, AM, Brazil
| | | | - Fernanda Castro de Lima
- Fellow Master degree in Veterinary Medicine, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Celso Vieira Lima
- Master, Fellow PhD degree in Nuclear Sciences and Techniques, School of Engineering, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
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HEIN ASHLEYL, OUELLETTE MICHELM, YAN YING. Radiation-induced signaling pathways that promote cancer cell survival (review). Int J Oncol 2014; 45:1813-9. [PMID: 25174607 PMCID: PMC4203326 DOI: 10.3892/ijo.2014.2614] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 08/01/2014] [Indexed: 12/12/2022] Open
Abstract
Radiation therapy is a staple cancer treatment approach that has significantly improved local disease control and the overall survival of cancer patients. However, its efficacy is still limited by the development of radiation resistance and the presence of residual disease after therapy that leads to cancer recurrence. Radiation impedes cancer cell growth by inducing cytotoxicity, mainly caused by DNA damage. However, radiation can also simultaneously induce multiple pro-survival signaling pathways, such as those mediated by AKT, ERK and ATM/ATR, which can lead to suppression of apoptosis, induction of cell cycle arrest and/or initiation of DNA repair. These signaling pathways act conjointly to reduce the magnitude of radiation-induced cytotoxicity and promote the development of radioresistance in cancer cells. Thus, targeting these pro-survival pathways has great potential for the radiosensitization of cancer cells. In the present review, we summarize the current literature on how these radiation‑activated signaling pathways promote cancer cell survival.
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Affiliation(s)
- ASHLEY L. HEIN
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA
| | - MICHEL M. OUELLETTE
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA
| | - YING YAN
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA
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Abstract
Ionizing radiation, like a variety of other cellular stress factors, can activate or down-regulate multiple signaling pathways, leading to either increased cell death or increased cell proliferation. Modulation of the signaling process, however, depends on the cell type, radiation dose, and culture conditions. The mitogen-activated protein kinase (MAPK) pathway transduces signals from the cell membrane to the nucleus in response to a variety of different stimuli and participates in various intracellular signaling pathways that control a wide spectrum of cellular processes, including growth, differentiation, and stress responses, and is known to have a key role in cancer progression. Multiple signal transduction pathways stimulated by ionizing radiation are mediated by the MAPK superfamily including the extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK. The ERK pathway, activated by mitogenic stimuli such as growth factors, cytokines, and phorbol esters, plays a major role in regulating cell growth, survival, and differentiation. In contrast, JNK and p38 MAPK are weakly activated by growth factors but respond strongly to stress signals including tumor necrosis factor (TNF), interleukin-1, ionizing and ultraviolet radiation, hyperosmotic stress, and chemotherapeutic drugs. Activation of JNK and p38 MAPK by stress stimuli is strongly associated with apoptotic cell death. MAPK signaling is also known to potentially influence tumor cell radiosensitivity because of their activity associated with radiation-induced DNA damage response. This review will discuss the MAPK signaling pathways and their roles in cellular radiation responses.
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Affiliation(s)
- Anupama Munshi
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Rajagopal Ramesh
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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Kaida A, Miura M. Visualizing the effect of tumor microenvironments on radiation-induced cell kinetics in multicellular spheroids consisting of HeLa cells. Biochem Biophys Res Commun 2013; 439:453-8. [PMID: 24016668 DOI: 10.1016/j.bbrc.2013.08.093] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 08/29/2013] [Indexed: 11/25/2022]
Abstract
In this study, we visualized the effect of tumor microenvironments on radiation-induced tumor cell kinetics. For this purpose, we utilized a multicellular spheroid model, with a diameter of ∼500 μm, consisting of HeLa cells expressing the fluorescent ubiquitination-based cell-cycle indicator (Fucci). In live spheroids, a confocal laser scanning microscope allowed us to clearly monitor cell kinetics at depths of up to 60 μm. Surprisingly, a remarkable prolongation of G2 arrest was observed in the outer region of the spheroid relative to monolayer-cultured cells. Scale, an aqueous reagent that renders tissues optically transparent, allowed visualization deeper inside spheroids. About 16 h after irradiation, a red fluorescent cell fraction, presumably a quiescent G0 cell fraction, became distinct from the outer fraction consisting of proliferating cells, most of which exhibited green fluorescence indicative of G2 arrest. Thereafter, the red cell fraction began to emit green fluorescence and remained in prolonged G2 arrest. Thus, for the first time, we visualized the prolongation of radiation-induced G2 arrest in spheroids and the differences in cell kinetics between the outer and inner fractions.
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Affiliation(s)
- Atsushi Kaida
- Section of Oral Radiation Oncology, Department of Oral Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
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Yang C, Wang Y, Zhang F, Sun G, Li C, Jing S, Liu Q, Cheng Y. Inhibiting UHRF1 expression enhances radiosensitivity in human esophageal squamous cell carcinoma. Mol Biol Rep 2013; 40:5225-35. [PMID: 23943380 DOI: 10.1007/s11033-013-2559-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 04/29/2013] [Indexed: 12/15/2022]
Abstract
Radiotherapy is an effective treatment for some esophageal cancers, but the molecular mechanisms of radiosensitivity remain unknown. Ubiquitin-like with PHD and ring finger domains 1 (UHRF1) is a novel nuclear protein which is overexpressed in various cancers but not yet examined in esophageal squamous cell carcinoma (ESCC). The correlation between UHRF1 and the radioresistance in ESCC is still unclear. In the present study, the expression of UHRF1 was examined by immunohistochemistry in specimens of ESCC patients treated with radiotherapy. The results showed that UHRF1 was significantly overexpressed in ESCC specimens. Overexpression of UHRF1 correlated significantly with advanced T-stage, positive lymph node metastasis and poor differentiation. In addition, UHRF1 was associated with radiotherapy response, in which overexpression of UHRF1 was observed more frequently in the radioresistant group than in the effective group. At the molecular level, inhibition of UHRF1 by lentivirus-mediated shRNA targeting UHRF1 increased the radiosensitivity and apoptosis, while decreased radiation-induced G2/M phase arrest in TE-1 cells. Moreover, inhibition of UHRF1 resulted in higher residual γH2AX expression after irradiation, but not initial γH2AX. Further study showed that inhibition of UHRF1 down-regulated the endogenous expressions of DNA repair protein Ku70 and Ku80 in TE-1 cells, and significantly inhibited the increase of these proteins after irradiation. Above all, our data suggested that UHRF1 might play an important role in radioresistance of ESCC, and inhibition of UHRF1 can increase the radiosensitivity of TE-1 cells by altering cell cycle progression, enhancing apoptosis, and decreasing DNA damage repair capacity.
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Affiliation(s)
- Congrong Yang
- Department of Radiation Oncology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, 050011, China
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Selective radiosensitization of human cervical cancer cells and normal cells by artemisinin through the abrogation of radiation-induced G2 block. Int J Gynecol Cancer 2012; 22:718-24. [PMID: 22552829 DOI: 10.1097/igc.0b013e31824a67c9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE Artemisinin has been shown to inhibit the growth of some human cancer cells. In this study, we investigated the radiosensitizing effects of artemisinin on cervical cancer cells and normal human fibroblast cells and also assessed some possible mechanisms for these effects. MATERIALS AND METHODS Two cervical cancer cell lines, HeLa and SiHa cells, and GM0639 normal human fibroblast cell line were treated with various concentrations of artemisinin plus radiation; the cell viability was tested using both 3-(4,5-dimethylthiazolyl-2-y1)-2, 5-diphenyltetrazolium bromide and clonogenic assays. Radiation dose-modifying factors were measured by clonogenic survival assay. Annexin V/propidium iodide assay for the evaluation of apoptosis and cell cycle phase were determined by flow cytometry, and the expression of the cell cycle-associated proteins Wee 1 and cyclin B1 were analyzed by Western blot analysis. RESULTS Artemisinin showed higher cytotoxicity in cervical cancer cell lines, especially in SiHa cells, than in the normal cell line. In both clonogenic assay and apoptosis, artemisinin sensitized the HeLa cancer cells to the cytotoxicity of radiation, yielding a dose-modifying factor of 1.24, but not SiHa cancer cells and GM normal cells. At a dose of 110 nmol/L, artemisinin did not change the distribution of cell cycle in 3 tested cell lines, but artemisinin abrogated the radiation-induced G2 blockade. Analyses of G2-checkpoint-related proteins, the activation of Wee 1 and depression of cyclin B1 expression induced by radiation, could be restored to the control level by artemisinin. CONCLUSIONS Given the unique cytotoxic profile of artemisinin on cancer cells and normal cells, artemisinin may be a potentially promising radiosensitizer through the regulation of the expression of G2 checkpoint-related proteins like Wee 1 and cyclin B1, and improve therapeutic ratios for the combination of artemisinin and ionizing irradiation in the treatment of patients with cervical cancer.
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Xie G, Zhan J, Tian Y, Liu Y, Chen Z, Ren C, Sun Q, Lian J, Chen L, Ruan J, Ye C, Sun A, Yuan Y. Mammosphere cells from high-passage MCF7 cell line show variable loss of tumorigenicity and radioresistance. Cancer Lett 2011; 316:53-61. [PMID: 22108532 DOI: 10.1016/j.canlet.2011.10.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 09/28/2011] [Accepted: 10/14/2011] [Indexed: 01/06/2023]
Abstract
Mammosphere culture of cancer cell lines is an important approach used for enrichment of stem-like cancer cells (SLCs), but over-subcultured cell lines have been experimentally shown to change properties over time. It remains unclear if mammosphere cells (MSs) derived from high-passage cancer cell lines retain the tumorigenicity and radioresistance seen in MSs from primary or low-passage cell lines. In this study, we report that mammospheres derived from MCF-7 sublines after different passage numbers were consistently enriched for CD44+/CD24(-/low) cells but were not consistently enriched for tumorigenic and radioresistant cells. The tumorigenicity and radioresistance of MSs were associated with their sphere-forming ability, proliferation ability in vitro, and intracellular reactive oxygen species (ROS) levels. The radioresistant MSs showed significant cell cycle arrest in G2/M phase after X-ray irradiation and expressed higher ataxia telangiectasia mutated (ATM) mRNA levels. These results suggest that MSs from high-passage cancer cell lines were not consistently enriched for stem-like cancer cells with higher tumorigenicity and enhanced radioresistance.
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Affiliation(s)
- Guozhu Xie
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
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Gogineni VR, Nalla AK, Gupta R, Dinh DH, Klopfenstein JD, Rao JS. Chk2-mediated G2/M cell cycle arrest maintains radiation resistance in malignant meningioma cells. Cancer Lett 2011; 313:64-75. [PMID: 21945852 DOI: 10.1016/j.canlet.2011.08.022] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 08/19/2011] [Accepted: 08/22/2011] [Indexed: 10/17/2022]
Abstract
In continuation to our studies on radioresistance in meningioma, here we show that radiation treatment (7Gy) induces G2/M cell cycle arrest in meningioma cells. Phosphorylation of Chk2, Cdc25c and Cdc2 were found to be key events since interference with Chk2 activation and cyclin B1/Cdc2 interaction led to permanent arrest followed by apoptosis. Irradiated cells showed recovery and formed aggressive intracranial tumors with rapid spread and morbidity. Nevertheless, knock down of uPAR with or without radiation induced permanent arrest in G2/M phase and subsequent apoptosis in vitro and in vivo. In conclusion, our data suggest that combination treatment with radiation and uPAR knock down or other inhibitors resulting in non-reversible G2/M arrest may be beneficial in the management of meningiomas.
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Affiliation(s)
- Venkateswara Rao Gogineni
- Departments of Cancer Biology & Pharmacology and Neurosurgery, University of Illinois College of Medicine at Peoria, Peoria, IL, USA
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Solanki AA, Liauw SL. Role of HMG-CoA reductase inhibitors with curative radiotherapy in men with prostate cancer. Open Access J Urol 2011; 3:95-104. [PMID: 24198641 PMCID: PMC3818949 DOI: 10.2147/oaju.s14245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Brachytherapy and external beam radiotherapy are effective and commonly used treatment modalities in men with localized prostate cancer. In this review, we explore the role of radiation therapy in the curative management of prostate cancer, including the use of conformal therapeutic techniques to allow for the escalation of radiation doses to tumor, along with the use of combined radiation and hormonal therapy to enhance disease outcomes in men with aggressive disease. We also review the possible anticancer role of HMG-CoA reductase inhibiting agents (statins) in men with prostate cancer. Laboratory evidence suggests that statins may have antineoplastic effects when used alone and may sensitize cells to radiation therapy when given in combination. We explore the biologic basis for an anticancer effect and the clinical evidence suggesting statins may aid in improving outcomes with radiation therapy for localized prostate cancer.
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Affiliation(s)
- Abhishek A Solanki
- Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, IL, USA
| | - Stanley L Liauw
- Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, IL, USA
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Fritz G, Brachetti C, Kaina B. Lovastatin causes sensitization of HeLa cells to ionizing radiation‐induced apoptosis by the abrogation of G2 blockage. Int J Radiat Biol 2009; 79:601-10. [PMID: 14555343 DOI: 10.1080/09553000310001609233] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE To investigate the effect of inhibition of Ras/Rho-regulated signalling by 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) on radiation-induced cell killing and apoptosis. MATERIALS AND METHODS Different human cell lines were pretreated or not with lovastatin before exposure to gamma-rays. Afterwards, radiation-induced cell killing, formation and repair of double-strand breaks, activation of radiation-inducible signal mechanisms (i.e. p53, p21, extracellular-signal-related kinase (ERK), NF-kappaB), changes in cell cycle progression and apoptosis were analysed. RESULTS As shown by a colony formation assay, lovastatin sensitized HeLa cells to gamma-radiation-induced cell killing. The lovastatin effect was cell-type specific. Neither the level of gamma-ray-induced double-strand breaks nor its repair were affected by lovastatin. Sensitization was independent of p53/p21Waf1- and NF-kappaB-related mechanisms. Radiation-stimulated activation of ERKs was attenuated by lovastatin. Cell cycle analyses revealed that the level of gamma-ray-induced G2 blockage was not affected by lovastatin. However, as analysed up to 72 h after irradiation, lovastatin pretreated cells showed an accelerated abrogation of G2 blockage as compared with the control. G2 abrogation is paralleled by an increase in the frequency of apoptotic and necrotic cells. CONCLUSIONS The data show that lovastatin can render human cells more sensitive to the cytotoxic effect of gamma-rays. This is related to abrogation of G2 blockage and a concomitant increase in apoptotic/necrotic cell death.
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Affiliation(s)
- G Fritz
- Institute of Toxicology, Division of Applied Toxicology, University of Mainz, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany.
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14
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Petrović I, Ristić-Fira A, Todorović D, Valastro L, Cirrone P, Cuttone G. Radiobiological analysis of human melanoma cells on the 62 MeV CATANA proton beam. Int J Radiat Biol 2009; 82:251-65. [PMID: 16690593 DOI: 10.1080/09553000600669859] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE To measure the ability of protons and gamma-rays to effect cell viability and cell survival of human HTB140 melanoma cells. MATERIALS AND METHODS Exponentially growing HTB140 cells were irradiated close to the Bragg peak maximum of the 62 MeV protons or with 60Co gamma-rays with single doses, ranging from 8 - 24 Gy. Cell viability using the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay was evaluated at 6 h, 24 h, 48 h or 7 days after irradiation and clonogenic survival was assessed at 7 days after irradiation. Cell cycle phase redistribution and the level of apoptosis were evaluated at 6 h and 48 h after irradiation. RESULTS The study of cell viability as a function of time (cell survival progression) and cell survival, using a clonal assay, demonstrated the considerably stronger inactivation effect of protons compared to gamma-rays with a relative biological effectiveness (RBE) of approximately 1.64. Cell cycle phase distribution and apoptosis levels with time enabled us to investigate the development and the character of the damage induced by irradiation. Due to the high radio-resistance of HTB140 cells, cell cycle phase redistribution exhibited only a modest cell accumulation in G2/M phase. Protons but not gamma-rays induced apoptosis. CONCLUSIONS It appears that protons reduce the number of HTB140 cells by apoptosis as well as by severe DNA damage, while gamma-rays eliminate viable cells primarily by the production of irreparable DNA damage. Protons have an increased RBE relative to gamma-rays.
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Affiliation(s)
- Ivan Petrović
- Vinca Institute of Nuclear Sciences, Belgrade, Serbia and Montenegro
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15
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Ohnishi K, Yokota S, Takahashi A, Ohnishi T. Induction of radiation resistance by a heat shock protein inhibitor, KNK437, in human glioblastoma cells. Int J Radiat Biol 2009; 82:569-75. [PMID: 16966184 DOI: 10.1080/09553000600876645] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE We examined the effects of a heat shock protein (hsp) inhibitor, N-formyl-3, 4-methylenedioxy-gamma-butyrolactam (KNK437), on the radiosensitivity of human glioblastoma cells (A-172). MATERIALS AND METHODS Effects of KNK437 on radiosensitivity and cell cycle regulation were examined using colony formation assays, flow cytometry analysis and Western blot analysis. KNK437 was added to the culture medium 1 h before X-ray irradiation at 50, 100 or 300 microM final concentration. RESULTS KNK437 induced the resistance of A-172 cells and human squamous cell carcinoma cells (SAS) to X-rays. Flow cytometry analysis showed that KNK437 alone efficiently induced A-172 cells to enter G2/M phase. Though A-172 cells irradiated with X-rays at 6 Gy showed no clear change in the cell cycle, the irradiated cells were induced to enter G2/M phase when they had been pre-treated with KNK437. By Western blot analysis, p53, 14-3-3sigma and cell division cycle 2 (cdc2) proteins that function in G2 arrest were observed to be persistently accumulated or phosphorylated in KNK437-treated cells, regardless of X-ray irradiation. CONCLUSIONS These results show that KNK437 causes cells to be resistant to radiation, and that this might be correlated with maintenance of G2 arrest in the cell cycle regulation.
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Affiliation(s)
- Ken Ohnishi
- Department of Biology, Nara Medical University School of Medicine, Kashihara, Nara, Japan
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16
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Chung EJ, Brown AP, Asano H, Mandler M, Burgan WE, Carter D, Camphausen K, Citrin D. In vitro and in vivo radiosensitization with AZD6244 (ARRY-142886), an inhibitor of mitogen-activated protein kinase/extracellular signal-regulated kinase 1/2 kinase. Clin Cancer Res 2009; 15:3050-7. [PMID: 19366835 DOI: 10.1158/1078-0432.ccr-08-2954] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE The mitogen-activated protein (MAP) kinase pathway is important for cell proliferation, survival, and differentiation, and is frequently up-regulated in cancers. The MAP kinase pathway is also activated after exposure to ionizing radiation. We investigated the effects of AZD6244 (ARRY-142886), an inhibitor of MAP kinase/extracellular signal-regulated kinase 1/2, on radiation response. EXPERIMENTAL DESIGN The effects of AZD6244 on the in vitro radiosensitivity of human cancer cell lines (A549, MiaPaCa2, and DU145) were evaluated using clonogenic assays. DNA damage repair was evaluated using gammaH2AX, and mitotic catastrophe was measured using nuclear fragmentation. Cell cycle effects were measured with flow cytometry. Growth delay was used to evaluate the effects of AZD6244 on in vivo tumor radiosensitivity. RESULTS Exposure of each cell line to AZD6244 before irradiation resulted in an increase in radiosensitivity with dose enhancement factors at a surviving fraction of 0.1, ranging from 1.16 to 2.0. No effects of AZD6244 on radiation-induced apoptosis or persistence of gammaH2AX foci after irradiation were detected. Cells treated with AZD6244 had an increased mitotic index and decreased Chk1 phosphorylation at 1 and 2 hours after irradiation. Mitotic catastrophe was increased in cells receiving AZD6244 and irradiation compared with the single treatments. In vivo studies revealed that AZD6244 administration to mice bearing A549 tumor xenografts resulted in a greater than additive increase in radiation-induced tumor growth delay (dose enhancement factor of 3.38). CONCLUSIONS These results indicate that AZD6244 can enhance tumor cell radiosensitivity in vitro and in vivo and suggest that this effect involves an increase in mitotic catastrophe.
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Znaczenie prognostyczne ekspresji cykliny D1 i cykliny B u pacjentów z rakiem krtani leczonych radioterapią. Otolaryngol Pol 2009; 63:136-40. [DOI: 10.1016/s0030-6657(09)70094-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Liu ZZ, Huang WY, Lin JS, Li XS, Lan X, Cai XK, Liang KH, Zhou HJ. Cell survival curve for primary hepatic carcinoma cells and relationship between SF(2) of hepatic carcinoma cells and radiosensitivity. World J Gastroenterol 2006; 11:7040-3. [PMID: 16437614 PMCID: PMC4717052 DOI: 10.3748/wjg.v11.i44.7040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To establish the cell survival curve for primary hepatic carcinoma cells and to study the relationship between SF(2) of primary hepatic carcinoma cells and radiosensitivity. METHODS Hepatic carcinoma cells were cultured in vitro using 39 samples of hepatic carcinoma at stages II-IV. Twenty-nine samples were cultured successfully in the fifth generation cells. After these cells were radiated with different dosages, the cell survival ratio and SF(2) were calculated by clonogenic assay and SF(2) model respectively. The relationship between SF(2) and the clinical pathological feature was analyzed. RESULTS Twenty-nine of thirty-nine samples were successfully cultured. After X-ray radiation of the fifth generation cells with 0, 2, 4, 6, 8 Gy, the cell survival rate was 41%, 36.5%, 31.0%, 26.8%, and 19%, respectively. There was a negative correlation between cell survival and irradiation dosage (r = -0.973, P<0.05). SF(2) ranged 0.28-0.78 and correlated with the clinical stage and pathological grade of hepatic carcinoma (P<0.05). There was a positive correlation between SF(2) and D0.5 (r = 0.773, P<0.05). CONCLUSION SF(2) correlates with the clinical stage and pathological grade of hepatic carcinoma and is a marker for predicting the radiosensitivity of hepatic carcinomas.
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Affiliation(s)
- Zhi-Zhong Liu
- Institute of Liver Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China.
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Moon MS, Kim JS, Kim TL, Yum JJ, Cho EW, Kim IG. Polyamine depletion partially reduces the radiation-induced cell death via cell cycle delay mediated by thioredoxin. Cell Biol Toxicol 2006; 22:137-47. [PMID: 16532286 DOI: 10.1007/s10565-006-0042-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2005] [Accepted: 01/05/2006] [Indexed: 11/29/2022]
Abstract
In previous studies, polyamine depletion by DFMO (alpha-difluoromethylornithine)-treatment reduced H(2)O(2)-induced apoptotic cell death by reduction of ferric ion uptake. In the present study, we analyzed the reduction of radiation-induced cell death by polyamine depletion. Exposure of HT29 cells to radiation induced severe cell death, but when cells were pretreated with DFMO, a specific inhibitor of polyamine biosynthesis, radiation-induced cell death was reduced to 50-60% of control. Cell cycle analysis showed that, in these cells, the time to reach the G(2)/M phase arrest was delayed for 20-24 h compared to the control cells, at which stage the fate of cells exposed to ionizing radiation is determined. DFMO-treated cells also showed a low level of thioredoxin, which is a high-level determinant of the cellular fate. To investigate the relationship between the G(2)/M phase arrest and the reduction of thioredoxin caused by polyamine depletion, we also analyzed thioredoxin-antisensed (asTRX) HT29 cells as for DFMO-treated cells. In asTRX-transfected cells, the gamma-irradiation-induced G(2)/M phase arrest was also significantly delayed and radiation-induced cell death was profoundly reduced, as in the DFMO-treated cells. Both sets of cells showed a decrease of cyclin D1 and an increment of HSP25, which are involved in radiation-induced cell cycle progress. Overall, these results suggest that polyamines are essential for normal cell death of HT29 cells triggered by gamma-radiation and that this is partially mediated by the regulation of thioredoxin expression.
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Affiliation(s)
- M S Moon
- Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Yuseong, Daejon, Korea
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Bucci B, D'Agnano I, Amendola D, Citti A, Raza GH, Miceli R, De Paula U, Marchese R, Albini S, Felsani A, Brunetti E, Vecchione A. Myc down-regulation sensitizes melanoma cells to radiotherapy by inhibiting MLH1 and MSH2 mismatch repair proteins. Clin Cancer Res 2005; 11:2756-67. [PMID: 15814658 DOI: 10.1158/1078-0432.ccr-04-1582] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Melanoma patients have a very poor prognosis with a response rate of <1% due to advanced diagnosis. This type of tumor is particularly resistant to conventional chemotherapy and radiotherapy, and the surgery remains the principal treatment for patients with localized melanoma. For this reason, there is particular interest in the melanoma biological therapy. EXPERIMENTAL DESIGN Using two p53 mutant melanoma models stably expressing an inducible c-myc antisense RNA, we have investigated whether Myc protein down-regulation could render melanoma cells more susceptible to radiotherapy, reestablishing apoptotic p53-independent pathway. In addition to address the role of p53 in the activation of apoptosis, we studied the effect of Myc down-regulation on radiotherapy sensitivity also in a p53 wild-type melanoma cell line. RESULTS Myc down-regulation is able per se to induce apoptosis in a fraction of the cell population (approximately 40% at 72 hours) and in combination with gamma radiation efficiently enhances the death process. In fact, approximately 80% of apoptotic cells are evident in Myc down-regulated cells exposed to gamma radiation for 72 hours compared with approximately 13% observed after only gamma radiation treatment. Consistent with the enhanced apoptosis is the inhibition of the MLH1 and MSH2 mismatch repair proteins, which, preventing the correction of ionizing radiation mismatches occurring during DNA replication, renders the cells more prone to radiation-induced apoptosis. CONCLUSIONS Data herein reported show that Myc down-regulation lowers the apoptotic threshold in melanoma cells by inhibiting MLH1 and MSH2 proteins, thus increasing cell sensitivity to gamma radiation in a p53-independent fashion. Our results indicate the basis for developing new antitumoral therapeutic strategy, improving the management of melanoma patients.
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Affiliation(s)
- Barbara Bucci
- Associazione Fatebenefratelli per la Ricerca-Centro Ricerca S. Pietro and Unita di Radioterapia Oncologica S. Pietro, Fatebenefratelli Hospital, Rome, Italy.
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Hyun JW, Cheon GJ, Kim HS, Lee YS, Choi EY, Yoon BH, Kim JS, Chung MH. Radiation sensitivity depends on OGG1 activity status in human leukemia cell lines. Free Radic Biol Med 2002; 32:212-20. [PMID: 11827746 DOI: 10.1016/s0891-5849(01)00793-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
To assess the role of 8-oxoguanine glycosylase (OGG1) in the cell defense against radiation injury, the radiation-induced cytotoxicities were compared between the mutant type KG-1 featuring a loss of OGG1 activity due to a homozygous mutation of Arg 229 Gln, and the wild type U937. While the following three obvious toxicities were displayed in KG-1, they were observed only minimally in U937. These were: a dramatic arrest at the G2/M phase indicated by a marked increase in both the number of G2/M cells and the expression of cyclin B1, cdc2, and mitotic phosphoprotein monoclonal-2 (MPM-2)-reactive proteins; a severe apoptosis shown by a marked increase in the number of cells with hypo-diploid DNA and DNA fragmentation; and as a result, a severe inhibition of cell growth and proliferation measured by the MTT test and [(3)H]-thymidine uptake assay. As expected, KG-1 exhibited a significant increase in the 8-hydroxyguanine level in DNA whereas U937 did not. However, the level of irradiation-induced lipid peroxidation was almost the same in both cell lines. All of these symptoms shown by KG-1 were observed in Molt-4 and CEM-CM3, which were also found to feature low OGG1 activity. These findings suggest that OGG1 plays an important role in cell survival from radiation-induced damage and are also indicative of the capability of 8-hydroxyguanine in DNA to induce cellular toxicities.
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Affiliation(s)
- Jin-Won Hyun
- Department of Pharmacology, Seoul National University College of Medicine, Seoul, South Korea
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Green LM, Murray DK, Bant AM, Kazarians G, Moyers MF, Nelson GA, Tran DT. Response of thyroid follicular cells to gamma irradiation compared to proton irradiation. I. Initial characterization of DNA damage, micronucleus formation, apoptosis, cell survival, and cell cycle phase redistribution. Radiat Res 2001; 155:32-42. [PMID: 11121213 DOI: 10.1667/0033-7587(2001)155[0032:rotfct]2.0.co;2] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The RBE of protons has been assumed to be equivalent to that of photons. The objective of this study was to determine whether radiation-induced DNA and chromosome damage, apoptosis, cell killing and cell cycling in organized epithelial cells was influenced by radiation quality. Thyroid-stimulating hormone-dependent Fischer rat thyroid cells, established as follicles, were exposed to gamma rays or proton beams delivered acutely over a range of physical doses. Gamma-irradiated cells were able to repair DNA damage relatively rapidly so that by 1 h postirradiation they had approximately 20% fewer exposed 3' ends than their counterparts that had been irradiated with proton beams. The persistence of free ends of DNA in the samples irradiated with the proton beam implies that either more initial breaks or a quantitatively different type of damage had occurred. These results were further supported by an increased frequency of chromosomal damage as measured by the presence of micronuclei. Proton-beam irradiation induced micronuclei at a rate of 2.4% per gray, which at 12 Gy translated to 40% more micronuclei than in comparable gamma-irradiated cultures. The higher rate of micronucleus formation and the presence of larger micronuclei in proton-irradiated cells was further evidence that a qualitatively more severe class of damage had been induced than was induced by gamma rays. Differences in the type of damage produced were detected in the apoptosis assay, wherein a significant lag in the induction of apoptosis occurred after gamma irradiation that did not occur with protons. The more immediate expression of apoptotic cells in the cultures irradiated with the proton beam suggests that the damage inflicted was more severe. Alternatively, the cell cycle checkpoint mechanisms required for recovery from such damage might not have been invoked. Differences based on radiation quality were also evident in the alpha components of cell survival curves (0.05 Gy(-1) for gamma rays, 0.12 Gy(-1) for protons), which suggests that the higher level of survival of gamma-irradiated cells could be attributed to the persistence of nonlethally irradiated thyrocytes and/or the capacity to repair damage more effectively than cells exposed to equal physical doses of protons. The final assessment in this study was radiation-induced cell cycle phase redistribution. Gamma rays and protons produced a similar dose-dependent redistribution toward a predominantly G(2)-phase population. From our cumulative results, it seems likely that a majority of the proton-irradiated cells would not continue to divide. In conclusion, these findings suggest that there are quantitative and qualitative differences in the biological effects of proton beams and gamma rays. These differences could be due to structured energy deposition from the tracks of primary protons and the associated high-LET secondary particles produced in the targets. The results suggest that a simple dose-equivalent approach to dosimetry may be inadequate to compare the biological responses of cells to photons and protons.
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Affiliation(s)
- L M Green
- Radiobiology Program-Department of Radiation Medicine, Loma Linda University, Chan Shun Pavilion Room A1010, 11175 Campus Street, Loma Linda, California 92354, USA
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