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Hambarde S, Manalo JM, Baskin DS, Sharpe MA, Helekar SA. Spinning magnetic field patterns that cause oncolysis by oxidative stress in glioma cells. Sci Rep 2023; 13:19264. [PMID: 37935811 PMCID: PMC10630398 DOI: 10.1038/s41598-023-46758-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 11/04/2023] [Indexed: 11/09/2023] Open
Abstract
Raising reactive oxygen species (ROS) levels in cancer cells to cause macromolecular damage and cell death is a promising anticancer treatment strategy. Observations that electromagnetic fields (EMF) elevate intracellular ROS and cause cancer cell death, have led us to develop a new portable wearable EMF device that generates spinning oscillating magnetic fields (sOMF) to selectively kill cancer cells while sparing normal cells in vitro and to shrink GBM tumors in vivo through a novel mechanism. Here, we characterized the precise configurations and timings of sOMF stimulation that produce cytotoxicity due to a critical rise in superoxide in two types of human glioma cells. We also found that the antioxidant Trolox reverses the cytotoxic effect of sOMF on glioma cells indicating that ROS play a causal role in producing the effect. Our findings clarify the link between the physics of magnetic stimulation and its mechanism of anticancer action, facilitating the development of a potential new safe noninvasive device-based treatment for GBM and other gliomas.
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Affiliation(s)
- Shashank Hambarde
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, Houston, TX, USA
- Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA
- Houston Methodist Research Institute, Houston, TX, USA
| | - Jeanne M Manalo
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, Houston, TX, USA
- Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA
- Houston Methodist Research Institute, Houston, TX, USA
| | - David S Baskin
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, Houston, TX, USA
- Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA
- Houston Methodist Research Institute, Houston, TX, USA
- Department of Neurosurgery, Weill Cornell Medical College, New York, NY, USA
| | - Martyn A Sharpe
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, Houston, TX, USA
- Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA
- Houston Methodist Research Institute, Houston, TX, USA
| | - Santosh A Helekar
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, Houston, TX, USA.
- Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA.
- Houston Methodist Research Institute, Houston, TX, USA.
- Department of Neurosurgery, Weill Cornell Medical College, New York, NY, USA.
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Pandey A, Hambarde S, Baskin DS, Helekar SA. Abstract 337: Antitumor effect of oncomagnetic therapy in glioblastoma. Cancer Res 2023. [DOI: 10.1158/1538-7445.am2023-337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Abstract
Background: Glioblastoma (GBM) is the most lethal primary malignant brain tumor with a median survival of 15-20 months. Concurrent temozolomide (TMZ) chemotherapy and radiation (XRT) remain the current standard of care (SOC) treatment for newly diagnosed GBM. The addition of tumor treating fields (TTFs) improves median survival from 16 to 20.9 months. This modest improvement underscores the urgent need to identify a new treatment modality as standalone therapy. We have reported recently that brief 2 - 6 h of daily brain stimulation with a new noninvasive, non-contact, magnetic stimulation device causes >30% reduction of contrast-enhanced tumor (CET) volume in an end-stage recurrent GBM patient after a ~30-day treatment.
Purpose: The noninvasive Oncomagnetic device developed in our laboratory selectively kills glioblastoma (GBM) and other cancer cells while sparing normal developing neurons and astrocytes in vitro. The spinning oscillating magnetic field (sOMF) generated by this device disrupts electron transport in the mitochondrial respiratory chain leading to a marked increase in reactive oxygen species (ROS) and consequent cancer cell death. However, the downstream molecular mechanism of sOMF action is under investigation. We studied the cellular and molecular effects of sOMF treatment on GBM cell lines and investigated the response to Oncomagnetic monotherapy (OMT) in a syngeneic mouse model. We treated LN229 and U87 GBM cells with sOMF with and without a sub-therapeutic dose of TMZ in vitro. To study the anticancer effect of sOMF in vivo, we developed syngeneic GBM tumors in BALB/c mice by stereotactic intracranial injection of GL261WT cells. Tumor growth was monitored periodically by MRI scans.
Results: Our results showed that sOMF significantly reduce cell proliferation and cell survival in vitro. We observed that sOMF induces DNA damage and arrests cells in G1 phase of cell cycle. OMT of tumor-bearing mice using a whole-body sOMF stimulation method caused a substantial retardation of tumor growth and reduction of the contrast-enhanced tumor volume in 9.4 T MRI scans. OMT also showed significant increase in overall survival in these mice.
Conclusion: These experiments contribute to unraveling the mechanism of action underlying the response to OMT in GBM and provide a strong rationale for a standalone Oncomagnetic therapy for GBM.
Citation Format: Arvind Pandey, Shashank Hambarde, David S. Baskin, Santosh A. Helekar. Antitumor effect of oncomagnetic therapy in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 337.
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Hambarde S, Pandey A, Baskin D, Helekar S. EXTH-68. ONCOMAGNETIC TREATMENT SELECTIVELY KILLS GLIOMA CANCER CELLS BY INDUCING OXIDATIVE STRESS AND DNA DAMAGE. Neuro Oncol 2022. [PMCID: PMC9661114 DOI: 10.1093/neuonc/noac209.866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Abstract
A new noninvasive therapeutic device developed in our laboratory called the Oncomagnetic device provides a novel approach to glioblastoma (GBM) treatment. It involves repeated stimulation with oscillating magnetic fields (sOMF) produced by spinning permanent magnets. It is technologically and mechanistically distinct from the Optune® device approved by the FDA for the treatment of newly diagnosed and recurrent GBM. Use of this device in one end-stage GBM patient reversed the progression of his recurrent tumor causing >30% reduction in its contrast-enhanced volume within 4 weeks of treatment. Mice with implanted mouse glioma cells in their brains also showed marked reduction in tumor size, increased survival (p< 0.05, n = 10) and higher DNA damage (g-H2AX foci) after sOMF treatment with a whole-body stimulation method developed by us. Normal mice exposed to sOMF for 4 months had no adverse effects on the brain and other organs. In-vitro, sOMF markedly increased reactive oxygen species (ROS) levels in cancer cells leading to the selective death of these cells, while sparing normal neurons and astrocytes. Detection of g-H2AX and 53BP1 foci showed that sOMF caused significant DNA damage in GBM cells and diffuse intrinsic pontine glioma (DIPG) cells but not in normal astroglial SVGp12 cells. Furthermore, sOMF exposure for just 2 h resulted in >40% loss of surviving GBM and DIPG cell colonies detected by clonogenic cell survival assay, similar to that produced by 2 Gy radiation dose. This loss was rescued by the antioxidant Trolox. These results indicate that sOMF stimulation has high anticancer potency comparable to low dose radiation therapy at the cellular level with an underlying mechanism of action that is substantially different from that proposed for Optune® TTF.
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Affiliation(s)
| | - Arvind Pandey
- Houston Methodist Research Institute , Houston, TX , USA
| | - David Baskin
- Peak Center, Dept of Neurosurgery, Houston Methodist Research Institute , Houston , USA
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Pandey A, Hambarde S, Baskin D, Helekar S. EXTH-65. SYNERGISTIC ONCOLYTIC EFFECTS OF TEMOZOLOMIDE AND ONCOMAGNETIC THERAPIES IN GLIOBLASTOMA. Neuro Oncol 2022. [PMCID: PMC9661042 DOI: 10.1093/neuonc/noac209.863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Abstract
The noninvasive Oncomagnetic device developed in our laboratory selectively kills glioblastoma (GBM) and other cancer cells while sparing normal developing neurons and astrocytes in vitro. We have reported that brief 2 – 6 h of daily Oncomagnetic brain stimulation causes >30% reduction of contrast-enhanced tumor (CET) volume in an end-stage recurrent GBM patient after a ~30-day treatment. We have evidence that the spinning oscillating magnetic fields (sOMF) generated by this device disrupts electron transport in the mitochondrial respiratory chain, at least in part by inhibiting the activity of Complex II succinate dehydrogenase, leading to a marked increase in reactive oxygen species (ROS) and consequent cancer cell death. Here, we further studied the cellular effects of sOMF treatment alone and in combination with Temozolomide (TMZ) on GBM cell lines with other methods and investigated the response to Oncomagnetic monotherapy (OMT) in a mouse GBM model. We treated LN229 and U87 GBM cells with sOMF with and without a sub-therapeutic dose of TMZ. To study the anticancer effect of sOMF in vivo, we developed syngeneic GBM tumors in BALB/c mice by stereotactic intracranial injection of GL261WT cells. Our results show that cytotoxic effects of sOMF or TMZ alone, as measured by the MTT assay and reduced cell survival, are significantly potentiated by combining the two treatments. OMT of tumor-bearing mice using a whole-body sOMF stimulation method causes substantial retardation of tumor growth and reduction of the CET volume in 9.4 T MRI scans. To study the molecular pathways involved in the treatment response we are mapping alterations in various key biomarkers in treated tumor tissues and comparing them with those in untreated controls. These experiments will unravel the molecular mechanism of action underlying the response to OMT in GBM and help develop a sound rationale for an effective therapeutic protocol.
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Affiliation(s)
- Arvind Pandey
- Houston Methodist Research Institute , Houston, TX , USA
| | | | - David Baskin
- Peak Center, Dept of Neurosurgery, Houston Methodist Research Institute , Houston , USA
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Hambarde S, Nguyen L, Manalo J, John B, Baskin DS, Helekar SA. Method for noninvasive whole-body stimulation with spinning oscillating magnetic fields and its safety in mice. Electromagn Biol Med 2022; 41:419-428. [PMID: 36154345 DOI: 10.1080/15368378.2022.2127108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We recently reported shrinkage of untreatable recurrent glioblastoma (GBM) in an end-stage patient using noninvasive brain stimulation with a spinning oscillating magnetic field (sOMF)-generating device called the Oncomagnetic device. Our in vitro experiments demonstrated selective cancer cell death while sparing normal cells by sOMF-induced increase in intracellular reactive oxygen species (ROS) levels due to magnetic perturbation of mitochondrial electron transport. Here, we describe the results of an in vivo study assessing the toxicity of chronic sOMF stimulation in mice using a newly constructed apparatus comprised of the sOMF-generating active components of the Oncomagnetic device. We chronically stimulated 10 normal 60-day old female C57BL/6 mice in their housing cages for 2 h 3 times a day, as in the patient treatment protocol, over 4 months. We also studied the effects of 2-h acute sOMF stimulation. Our observations and those of blinded independent veterinary staff observers, indicated no significant adverse effects of chronic or acute sOMF stimulation on the health, behavior, electrocardiographic and electroencephalographic activities, hematologic profile, and brain and other tissue and organ morphology of treated mice compared to age-matched untreated control mice. These findings suggest that short- and long-term therapies with the Oncomagnetic device are safe and well tolerated.
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Affiliation(s)
- Shashank Hambarde
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, Houston, TX, USA.,Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA.,Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA
| | - Lisa Nguyen
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, Houston, TX, USA.,Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA.,Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA.,Houston Methodist Magnetic Stimulation Device Core, Houston, TX, USA
| | - Jeanne Manalo
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, Houston, TX, USA.,Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA.,Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA
| | - Blessy John
- Houston Methodist Magnetic Stimulation Device Core, Houston, TX, USA
| | - David S Baskin
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, Houston, TX, USA.,Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA.,Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA.,Department of Neurosurgery, Weill Cornell Medical College, New York, NY, USA
| | - Santosh A Helekar
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, Houston, TX, USA.,Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA.,Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA.,Houston Methodist Magnetic Stimulation Device Core, Houston, TX, USA.,Department of Neurosurgery, Weill Cornell Medical College, New York, NY, USA
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Baskin DS, Sharpe M, Hambarde S, Helekar S. 341 SOncomagnetics: A Potential New Noninvasive Magnetic Stimulation Technology to Treat Glioblastoma. Neurosurgery 2022. [DOI: 10.1227/neu.0000000000001880_341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Pichumani K, Ijare O, Hambarde S, Sharpe M, John B, Baskin D, Helekar S. TAMI-13. MODULATION OF REDUCTIVE CARBOXYLATION FLUX OF GLUTAMINE IN GLIOBLASTOMA CELLS BY USING OSCILLATING MAGNETIC FIELD. Neuro Oncol 2021. [DOI: 10.1093/neuonc/noab196.797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Increased cell proliferation in glioblastoma (GBM) leads to hypoxia in the tumor microenvironment. This is a major concern in GBM patients as it promotes tumor invasion. Glutaminolysis is a hallmark of cancer cells and under hypoxic conditions glutamine metabolism proceeds through reductive carboxylation pathway. Recently, we have shown that oscillating magnetic field (OMF) produces oncolytic effects which can influence cellular metabolism. Here, we have explored the effect of OMF on glutamine metabolism in GBM cells. Patient-derived GBM cells were grown in high glucose (25 mM) DMEM supplemented with 20% fetal bovine serum (FBS), 2.0 mM glutamine and 1.0 mM pyruvate at 37 °C under humidified air and 5% CO2. Cells were divided into 2 groups (Test and Sham; n = 4 each group). When reached confluency (~2.0×106 cells/mL), cells in both groups were treated with 4.0 mM of [U-13C]glutamine in DMEM (supplemented with 20% FBS, and 1.0 mM pyruvate). The “Test” group was subjected to OMF for 3 hours, and the “Sham” group was treated similar to the “Test” group but with non-magnetic rods of the same dimensions as the magnets in the Test group. After 3 h, cells were harvested in 50% methanol analyzed by GC-MS. The 13C-isotopomer analysis showed that glutamine metabolism in GBM cells proceeds through reduction carboxylation, confirmed by the higher levels of M+5 citrate (15.42 ± 1.28 % ) than M+4 citrate (2.05 ± 0.28 %). When GBM cells were treated with OMF, a statistically significant decrease in the citrate M+5 was observed, compared to the “Sham” treated group (15.42 ± 1.28 % vs. 8.89 ± 1.30 %; p = 0.0003). This decrease in M+5 citrate upon OMF treatment clearly indicates that the OMF decreases the reductive carboxylation flux of glutamine in GBM cells which would have therapeutic value in treating GBM patients.
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Affiliation(s)
| | - Omkar Ijare
- Houston Methodist Research Institute, Houston, TX, USA
| | | | - Martyn Sharpe
- Houston Methodist Research Institute, Houston, TX, USA
| | - Blessy John
- Houston Methodist Research Institute, Houston, TX, USA
| | - David Baskin
- Houston Methodist Research Institute, Houston, TX, USA
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Ijare OB, Hambarde S, Brasil da Costa FH, Lopez S, Sharpe MA, Helekar SA, Hangel G, Bogner W, Widhalm G, Bachoo RM, Baskin DS, Pichumani K. Glutamine anaplerosis is required for amino acid biosynthesis in human meningiomas. Neuro Oncol 2021; 24:556-568. [PMID: 34515312 DOI: 10.1093/neuonc/noab219] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND We postulate that meningiomas undergo distinct metabolic reprogramming in tumorigenesis and unravelling their metabolic phenotypes provide new therapeutic insights. Glutamine catabolism is key to the growth and proliferation of tumors. Here, we investigated the metabolomics of freshly resected meningiomas and glutamine metabolism in patient-derived meningioma cells. METHODS 1H NMR spectroscopy of tumor tissues from 33 meningioma patients was used to differentiate the metabolite profiles of grade-I and grade-II meningiomas. Glutamine metabolism was examined using 13C/ 15N glutamine tracer, in five patient-derived meningioma cells. RESULTS Alanine, lactate, glutamate, glutamine, and glycine were predominantly elevated only in grade-II meningiomas by 74%, 76%, 35%, 75% and 33% respectively, with alanine, and glutamine being statistically significant (p ≤ 0.02). 13C/ 15N glutamine tracer experiments revealed that both grade-I and -II meningiomas actively metabolize glutamine to generate various key carbon intermediates including alanine and proline that are necessary for the tumor growth. Also, it is shown that glutaminase (GLS1) inhibitor, CB-839 is highly effective in downregulating glutamine metabolism and decreasing proliferation in meningioma cells. CONCLUSION Alanine and glutamine/glutamate are mainly elevated in grade-II meningiomas. Grade-I meningiomas possess relatively higher glutamine metabolism providing carbon/nitrogen for the biosynthesis of key nonessential amino acids. GLS1 inhibitor (CB-839) would be very effective in downregulating glutamine metabolic pathways in grade-I meningiomas leading to decreased cellular proliferation.
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Affiliation(s)
- Omkar B Ijare
- Kenneth R. Peak Brain and Pituitary Tumor Treatment Center, Department of Neurosurgery, Houston Methodist Neurological Institute, Houston Methodist Hospital and Research Institute, Houston, TX, USA
| | - Shashank Hambarde
- Kenneth R. Peak Brain and Pituitary Tumor Treatment Center, Department of Neurosurgery, Houston Methodist Neurological Institute, Houston Methodist Hospital and Research Institute, Houston, TX, USA
| | - Fabio Henrique Brasil da Costa
- Kenneth R. Peak Brain and Pituitary Tumor Treatment Center, Department of Neurosurgery, Houston Methodist Neurological Institute, Houston Methodist Hospital and Research Institute, Houston, TX, USA
| | - Sophie Lopez
- Kenneth R. Peak Brain and Pituitary Tumor Treatment Center, Department of Neurosurgery, Houston Methodist Neurological Institute, Houston Methodist Hospital and Research Institute, Houston, TX, USA
| | - Martyn A Sharpe
- Kenneth R. Peak Brain and Pituitary Tumor Treatment Center, Department of Neurosurgery, Houston Methodist Neurological Institute, Houston Methodist Hospital and Research Institute, Houston, TX, USA
| | - Santosh A Helekar
- Kenneth R. Peak Brain and Pituitary Tumor Treatment Center, Department of Neurosurgery, Houston Methodist Neurological Institute, Houston Methodist Hospital and Research Institute, Houston, TX, USA.,Weill Cornell Medical College, New York, NY, USA
| | - Gilbert Hangel
- High-field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Bogner
- High-field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Georg Widhalm
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
| | - Robert M Bachoo
- Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX, USA
| | - David S Baskin
- Kenneth R. Peak Brain and Pituitary Tumor Treatment Center, Department of Neurosurgery, Houston Methodist Neurological Institute, Houston Methodist Hospital and Research Institute, Houston, TX, USA.,Weill Cornell Medical College, New York, NY, USA
| | - Kumar Pichumani
- Kenneth R. Peak Brain and Pituitary Tumor Treatment Center, Department of Neurosurgery, Houston Methodist Neurological Institute, Houston Methodist Hospital and Research Institute, Houston, TX, USA.,Weill Cornell Medical College, New York, NY, USA
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Helekar SA, Hambarde S, Ijare OB, Pichumani K, Baskin DS, Sharpe MA. Selective induction of rapid cytotoxic effect in glioblastoma cells by oscillating magnetic fields. J Cancer Res Clin Oncol 2021; 147:3577-3589. [PMID: 34477946 DOI: 10.1007/s00432-021-03787-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 08/28/2021] [Indexed: 01/03/2023]
Abstract
PURPOSE The mechanisms underlying anticancer effects of electromagnetic fields are poorly understood. An alternating electric field-generating therapeutic device called Optune™ device has been approved for the treatment of glioblastoma (GBM). We have developed a new device that generates oscillating magnetic fields (OMF) by rapid rotation of strong permanent magnets in specially designed patterns of frequency and timing and have used it to treat an end-stage recurrent GBM patient under an expanded access/compassionate use treatment protocol. Here, we ask whether OMF causes selective cytotoxic effects in GBM and whether it is through generation of reactive oxygen species (ROS). METHODS We stimulated patient derived GBM cells, lung cancer cells, normal human cortical neurons, astrocytes, and bronchial epithelial cells using OMF generators (oncoscillators) of our Oncomagnetic Device and compared the results to those obtained under unstimulated or sham-stimulated control conditions. Quantitative fluorescence microscopy was used to assess cell morphology, viability, and ROS production mechanisms. RESULTS We find that OMF induces highly selective cell death of patient derived GBM cells associated with activation of caspase 3, while leaving normal tissue cells undamaged. The cytotoxic effect of OMF is also seen in pulmonary cancer cells. The underlying mechanism is a marked increase in ROS in the mitochondria, possibly in part through perturbation of the electron flow in the respiratory chain. CONCLUSION Rotating magnetic fields produced by a new noninvasive device selectively kill cultured human glioblastoma and non-small cell lung cancer cells by raising intracellular reactive oxygen species, but not normal human tissue cells.
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Affiliation(s)
- Santosh A Helekar
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, 6445 Main St., Floor 24, Houston, TX, 77030, USA.
- Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA.
- Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA.
- Department of Neurosurgery, Weill Cornell Medical College, New York, NY, USA.
| | - Shashank Hambarde
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, 6445 Main St., Floor 24, Houston, TX, 77030, USA
- Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA
- Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA
| | - Omkar B Ijare
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, 6445 Main St., Floor 24, Houston, TX, 77030, USA
- Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA
- Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA
| | - Kumar Pichumani
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, 6445 Main St., Floor 24, Houston, TX, 77030, USA
- Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA
- Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA
- Department of Neurosurgery, Weill Cornell Medical College, New York, NY, USA
| | - David S Baskin
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, 6445 Main St., Floor 24, Houston, TX, 77030, USA
- Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA
- Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA
- Department of Neurosurgery, Weill Cornell Medical College, New York, NY, USA
| | - Martyn A Sharpe
- Kenneth R. Peak Center for Brain and Pituitary Tumor Treatment and Research, Houston Methodist Hospital, 6445 Main St., Floor 24, Houston, TX, 77030, USA
- Department of Neurosurgery, Houston Methodist Hospital, Houston, TX, USA
- Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, USA
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Hambarde S, Tsai CL, Pandita RK, Bacolla A, Maitra A, Charaka V, Hunt CR, Kumar R, Limbo O, Le Meur R, Chazin WJ, Tsutakawa SE, Russell P, Schlacher K, Pandita TK, Tainer JA. EXO5-DNA structure and BLM interactions direct DNA resection critical for ATR-dependent replication restart. Mol Cell 2021; 81:2989-3006.e9. [PMID: 34197737 PMCID: PMC8720176 DOI: 10.1016/j.molcel.2021.05.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 04/09/2021] [Accepted: 05/24/2021] [Indexed: 02/07/2023]
Abstract
Stalled DNA replication fork restart after stress as orchestrated by ATR kinase, BLM helicase, and structure-specific nucleases enables replication, cell survival, and genome stability. Here we unveil human exonuclease V (EXO5) as an ATR-regulated DNA structure-specific nuclease and BLM partner for replication fork restart. We find that elevated EXO5 in tumors correlates with increased mutation loads and poor patient survival, suggesting that EXO5 upregulation has oncogenic potential. Structural, mechanistic, and mutational analyses of EXO5 and EXO5-DNA complexes reveal a single-stranded DNA binding channel with an adjacent ATR phosphorylation motif (T88Q89) that regulates EXO5 nuclease activity and BLM binding identified by mass spectrometric analysis. EXO5 phospho-mimetic mutant rescues the restart defect from EXO5 depletion that decreases fork progression, DNA damage repair, and cell survival. EXO5 depletion furthermore rescues survival of FANCA-deficient cells and indicates EXO5 functions epistatically with SMARCAL1 and BLM. Thus, an EXO5 axis connects ATR and BLM in directing replication fork restart.
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Affiliation(s)
- Shashank Hambarde
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA; Department of Neurosurgery, The Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Chi-Lin Tsai
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Raj K Pandita
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Albino Bacolla
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Anirban Maitra
- Sheikh Ahmed Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Vijay Charaka
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Clayton R Hunt
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Rakesh Kumar
- School of Biotechnology, Shri Mata Vashino Devi University, Katra, Jammu and Kashmir, 182320, India
| | - Oliver Limbo
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Remy Le Meur
- Departments of Biochemistry and Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Walter J Chazin
- Departments of Biochemistry and Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Susan E Tsutakawa
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Paul Russell
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Katharina Schlacher
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Tej K Pandita
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA; Department of Neurosurgery, The Houston Methodist Research Institute, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - John A Tainer
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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Hambarde S, Sharpe M, Baskin D, Helekar S. CBIO-07. CELL DEATH INDUCED BY AN OSCILLATING MAGNETIC FIELD IN PATIENT DERIVED GLIOBLASTOMA CELLS IS MEDIATED BY REACTIVE OXYGEN SPECIES. Neuro Oncol 2020. [DOI: 10.1093/neuonc/noaa215.067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Noninvasive cancer therapy with minimal side effects would be ideal for improving patient outcome in the clinic. We have developed a novel therapy using strong rotating magnets mounted on a helmet. They generate oscillating magnetic fields (OMF) that penetrate through the skull and cover the entire brain. We have demonstrated that OMF can effectively kill patient derived glioblastoma (GBM) cells in cell culture without having cytotoxic effects on cortical neurons and normal human astrocytes (NHA). Exposure of GBM cells to OMF reduced the cell viability by 33% in comparison to sham-treated cells (p< 0.001), while not affecting NHA cell viability. Time lapse video-microscopy for 16 h after OMF exposure showed a marked elevation of mitochondrial reactive oxygen species (ROS), and rapid apoptosis of GBM cells due to activation of caspase 3. Addition of a potent antioxidant vitamin E analog Trolox effectively blocked OMF-induced GBM cell death. Furthermore, OMF significantly potentiated the cytotoxic effect of the pro-oxidant Benzylamine. The results of our studies demonstrate that OMF-induced cell death is mediated by ROS generation. These results demonstrate a potent oncolytic effect on GBM cells that is novel and unrelated to any previously described therapy, including a very different mechanism of action and different technology compared to Optune therapy. The effect is very powerful, and unlike Optune, can be seen within hours after initiation of treatment. We believe that this technology holds great promise for new, effective and nontoxic treatment of glioblastoma.
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Affiliation(s)
| | - Martyn Sharpe
- Houston Methodist Research Institute, Houston, TX, USA
| | - David Baskin
- Houston Methodist Research Institute, Houston, TX, USA
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12
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Tsai CL, Hambarde S, Pandita TK, Tainer JA. [4Fe–4S] cluster-containing human exonuclease V acts as a novel replication fork restart factor. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s0108767319098581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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13
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Horikoshi N, Sharma D, Leonard F, Pandita RK, Charaka VK, Hambarde S, Horikoshi NT, Gaur Khaitan P, Chakraborty S, Cote J, Godin B, Hunt CR, Pandita TK. Pre-existing H4K16ac levels in euchromatin drive DNA repair by homologous recombination in S-phase. Commun Biol 2019; 2:253. [PMID: 31286070 PMCID: PMC6611875 DOI: 10.1038/s42003-019-0498-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 05/29/2019] [Indexed: 12/22/2022] Open
Abstract
The homologous recombination (HR) repair pathway maintains genetic integrity after DNA double-strand break (DSB) damage and is particularly crucial for maintaining fidelity of expressed genes. Histone H4 acetylation on lysine 16 (H4K16ac) is associated with transcription, but how pre-existing H4K16ac directly affects DSB repair is not known. To answer this question, we used CRISPR/Cas9 technology to introduce I-SceI sites, or repair pathway reporter cassettes, at defined locations within gene-rich (high H4K16ac/euchromatin) and gene-poor (low H4K16ac/heterochromatin) regions. The frequency of DSB repair by HR is higher in gene-rich regions. Interestingly, artificially targeting H4K16ac at specific locations using gRNA/dCas9-MOF increases HR frequency in euchromatin. Finally, inhibition/depletion of RNA polymerase II or Cockayne syndrome B protein leads to decreased recruitment of HR factors at DSBs. These results indicate that the pre-existing H4K16ac status at specific locations directly influences the repair of local DNA breaks, favoring HR in part through the transcription machinery.
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Affiliation(s)
- Nobuo Horikoshi
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030 USA
- Present Address: Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611 USA
| | - Dharmendra Sharma
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030 USA
| | - Fransisca Leonard
- Department of Nanomedicine, The Houston Methodist Research Institute, Houston, TX 77030 USA
| | - Raj K. Pandita
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030 USA
| | - Vijaya K. Charaka
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030 USA
| | - Shashank Hambarde
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030 USA
| | - Nobuko T. Horikoshi
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030 USA
| | - Puja Gaur Khaitan
- Department of Surgery, The Houston Methodist Research Institute, Houston, TX 77030 USA
- Present Address: Department of Surgery, Medstar Washington Hospital Center, Washington, DC 20010 USA
| | - Sharmistha Chakraborty
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030 USA
| | - Jacques Cote
- St. Patrick Research Group in Basic Oncology, Laval University Cancer Research Center, Quebec City, QC G1V4G2 Canada
| | - Biana Godin
- Department of Nanomedicine, The Houston Methodist Research Institute, Houston, TX 77030 USA
| | - Clayton R. Hunt
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030 USA
| | - Tej K. Pandita
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030 USA
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14
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Ge C, Vilfranc CL, Che L, Pandita RK, Hambarde S, Andreassen PR, Niu L, Olowokure O, Shah S, Waltz SE, Zou L, Wang J, Pandita TK, Du C. The BRUCE-ATR Signaling Axis Is Required for Accurate DNA Replication and Suppression of Liver Cancer Development. Hepatology 2019; 69:2608-2622. [PMID: 30693543 PMCID: PMC6541504 DOI: 10.1002/hep.30529] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 01/23/2019] [Indexed: 01/10/2023]
Abstract
Replication fork stability during DNA replication is vital for maintenance of genomic stability and suppression of cancer development in mammals. ATR (ataxia-telangiectasia mutated [ATM] and RAD3-related) is a master regulatory kinase that activates the replication stress response to overcome replication barriers. Although many downstream effectors of ATR have been established, the upstream regulators of ATR and the effect of such regulation on liver cancer remain unclear. The ubiquitin conjugase BRUCE (BIR Repeat containing Ubiquitin-Conjugating Enzyme) is a guardian of chromosome integrity and activator of ATM signaling, which promotes DNA double-strand break repair through homologous recombination. Here we demonstrate the functions for BRUCE in ATR activation in vitro and liver tumor suppression in vivo. BRUCE is recruited to induced DNA damage sites. Depletion of BRUCE inhibited multiple ATR-dependent signaling events during replication stress, including activation of ATR itself, phosphorylation of its downstream targets CHK1 and RPA, and the mono-ubiquitination of FANCD2. Consequently, BRUCE deficiency resulted in stalled DNA replication forks and increased firing of new replication origins. The in vivo impact of BRUCE loss on liver tumorigenesis was determined using the hepatocellular carcinoma model induced by genotoxin diethylnitrosamine. Liver-specific knockout of murine Bruce impaired ATR activation and exacerbated inflammation, fibrosis and hepatocellular carcinoma, which exhibited a trabecular architecture, closely resembling human hepatocellular carcinoma (HCC). In humans, the clinical relevance of BRUCE down-regulation in liver disease was found in hepatitis, cirrhosis, and HCC specimens, and deleterious somatic mutations of the Bruce gene was found in human hepatocellular carcinoma in the Cancer Genome Atlas database. Conclusion: These findings establish a BRUCE-ATR signaling axis in accurate DNA replication and suppression of liver cancer in mice and humans and provides a clinically relevant HCC mouse model.
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Affiliation(s)
- Chunmin Ge
- Department of Cancer and Cell Biology, University of Cincinnati, Cincinnati, Ohio 45267
| | | | - Lixiao Che
- Department of Cancer and Cell Biology, University of Cincinnati, Cincinnati, Ohio 45267
| | - Raj K. Pandita
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston Texas 77030
| | - Shashank Hambarde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston Texas 77030
| | - Paul R. Andreassen
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children Hospital Medical Center, Cincinnati, Ohio 45229
| | - Liang Niu
- Department of Environmental Health, University of Cincinnati, Cincinnati, Ohio 45267
| | - Olugbenga Olowokure
- Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio 45267
| | - Shimul Shah
- University of Cincinnati College of Medicine, University of Cincinnati, Cincinnati, Ohio 45267
| | - Susan E. Waltz
- Department of Cancer and Cell Biology, University of Cincinnati, Cincinnati, Ohio 45267
| | - Lee Zou
- Department of Pathology, Massachusetts General Hospital Cancer Center; Harvard Medical School, Charlestown, MA 02129
| | - Jiang Wang
- Department of Pathology, University of Cincinnati, Cincinnati, Ohio 45267
| | - Tej K. Pandita
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston Texas 77030
| | - Chunying Du
- Department of Cancer and Cell Biology, University of Cincinnati, Cincinnati, Ohio 45267,Corresponding author: Chunying Du, Ph.D. Phone: (513) 558-4803,
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15
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Moruno-Manchon JF, Koellhoffer EC, Gopakumar J, Hambarde S, Kim N, McCullough LD, Tsvetkov AS. The G-quadruplex DNA stabilizing drug pyridostatin promotes DNA damage and downregulates transcription of Brca1 in neurons. Aging (Albany NY) 2018; 9:1957-1970. [PMID: 28904242 PMCID: PMC5636668 DOI: 10.18632/aging.101282] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/25/2017] [Indexed: 01/01/2023]
Abstract
The G-quadruplex is a non-canonical DNA secondary structure formed by four DNA strands containing multiple runs of guanines. G-quadruplexes play important roles in DNA recombination, replication, telomere maintenance, and regulation of transcription. Small molecules that stabilize the G-quadruplexes alter gene expression in cancer cells. Here, we hypothesized that the G-quadruplexes regulate transcription in neurons. We discovered that pyridostatin, a small molecule that specifically stabilizes G-quadruplex DNA complexes, induced neurotoxicity and promoted the formation of DNA double–strand breaks (DSBs) in cultured neurons. We also found that pyridostatin downregulated transcription of the Brca1 gene, a gene that is critical for DSB repair. Importantly, in an in vitro gel shift assay, we discovered that an antibody specific to the G-quadruplex structure binds to a synthetic oligonucleotide, which corresponds to the first putative G-quadruplex in the Brca1 gene promoter. Our results suggest that the G-quadruplex complexes regulate transcription in neurons. Studying the G-quadruplexes could represent a new avenue for neurodegeneration and brain aging research.
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Affiliation(s)
- Jose F Moruno-Manchon
- Department of Neurobiology and Anatomy, the University of Texas McGovern Medical School at Houston, TX 77030, USA
| | - Edward C Koellhoffer
- Department of Neurology, the University of Texas McGovern Medical School at Houston, TX 77030, USA
| | - Jayakrishnan Gopakumar
- Summer Research Program at the University of Texas McGovern Medical School at Houston, TX 77030, USA
| | - Shashank Hambarde
- Department of Microbiology and Molecular Genetics, the University of Texas McGovern Medical School at Houston, TX 77030, USA
| | - Nayun Kim
- Department of Microbiology and Molecular Genetics, the University of Texas McGovern Medical School at Houston, TX 77030, USA.,The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Louise D McCullough
- Department of Neurology, the University of Texas McGovern Medical School at Houston, TX 77030, USA.,The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Andrey S Tsvetkov
- Department of Neurobiology and Anatomy, the University of Texas McGovern Medical School at Houston, TX 77030, USA.,The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA.,UTHealth Consortium on Aging, the University of Texas McGovern Medical School, Houston, TX 77030, USA
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16
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Chakraborty S, Pandita RK, Hambarde S, Mattoo AR, Charaka V, Ahmed KM, Iyer SP, Hunt CR, Pandita TK. SMARCAD1 Phosphorylation and Ubiquitination Are Required for Resection during DNA Double-Strand Break Repair. iScience 2018; 2:123-135. [PMID: 29888761 PMCID: PMC5993204 DOI: 10.1016/j.isci.2018.03.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/16/2018] [Accepted: 02/28/2018] [Indexed: 02/08/2023] Open
Abstract
The chromatin remodeling factor SMARCAD1, an SWI/SNF ATPase family member, has a role in 5' end resection at DNA double-strand breaks (DSBs) to produce single-strand DNA (ssDNA), a critical step for subsequent checkpoint and repair factor loading to remove DNA damage. However, the mechanistic details of SMARCAD1 coupling to the DNA damage response and repair pathways remains unknown. Here we report that SMARCAD1 is recruited to DNA DSBs through an ATM-dependent process. Depletion of SMARCAD1 reduces ionizing radiation (IR)-induced repairosome foci formation and DSB repair by homologous recombination (HR). IR induces SMARCAD1 phosphorylation at a conserved T906 by ATM kinase, a modification essential for SMARCAD1 recruitment to DSBs. Interestingly, T906 phosphorylation is also important for SMARCAD1 ubiquitination by RING1 at K905. Both these post-translational modifications are critical for regulating the role of SMARCAD1 in DNA end resection, HR-mediated repair, and cell survival after DNA damage.
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Affiliation(s)
- Sharmistha Chakraborty
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA.
| | - Raj K Pandita
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Shashank Hambarde
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Abid R Mattoo
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Vijaya Charaka
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Kazi M Ahmed
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Swaminathan P Iyer
- Department of Hematology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Clayton R Hunt
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Tej K Pandita
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA.
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17
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Horikoshi N, Pandita RK, Mujoo K, Hambarde S, Sharma D, Mattoo AR, Chakraborty S, Charaka V, Hunt CR, Pandita TK. β2-spectrin depletion impairs DNA damage repair. Oncotarget 2018; 7:33557-70. [PMID: 27248179 PMCID: PMC5085102 DOI: 10.18632/oncotarget.9677] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/20/2016] [Indexed: 12/22/2022] Open
Abstract
β2-Spectrin (β2SP/SPTBN1, gene SPTBN1) is a key TGF-β/SMAD3/4 adaptor and transcriptional cofactor that regulates TGF-β signaling and can contribute to liver cancer development. Here we report that cells deficient in β2-Spectrin (β2SP) are moderately sensitive to ionizing radiation (IR) and extremely sensitive to agents that cause interstrand cross-links (ICLs) or replication stress. In response to treatment with IR or ICL agents (formaldehyde, cisplatin, camptothecin, mitomycin), β2SP deficient cells displayed a higher frequency of cells with delayed γ-H2AX removal and a higher frequency of residual chromosome aberrations. Following hydroxyurea (HU)-induced replication stress, β2SP-deficient cells displayed delayed disappearance of γ-H2AX foci along with defective repair factor recruitment (MRE11, CtIP, RAD51, RPA, and FANCD2) as well as defective restart of stalled replication forks. Repair factor recruitment is a prerequisite for initiation of DNA damage repair by the homologous recombination (HR) pathway, which was also defective in β2SP deficient cells. We propose that β2SP is required for maintaining genomic stability following replication fork stalling, whether induced by either ICL damage or replicative stress, by facilitating fork regression as well as DNA damage repair by homologous recombination.
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Affiliation(s)
- Nobuo Horikoshi
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA.,Department of Radiation Oncology, University of Texas Southwestern Medical School, Dallas, TX, USA
| | - Raj K Pandita
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA.,Department of Radiation Oncology, University of Texas Southwestern Medical School, Dallas, TX, USA
| | - Kalpana Mujoo
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
| | - Shashank Hambarde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA.,Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Dharmendra Sharma
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
| | - Abid R Mattoo
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
| | - Sharmistha Chakraborty
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA.,Department of Radiation Oncology, University of Texas Southwestern Medical School, Dallas, TX, USA
| | - Vijaya Charaka
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
| | - Clayton R Hunt
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA.,Department of Radiation Oncology, University of Texas Southwestern Medical School, Dallas, TX, USA
| | - Tej K Pandita
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA.,Department of Radiation Oncology, University of Texas Southwestern Medical School, Dallas, TX, USA
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18
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Mujoo K, Pandita RK, Tiwari A, Charaka V, Chakraborty S, Singh DK, Hambarde S, Hittelman WN, Horikoshi N, Hunt CR, Khanna KK, Kots AY, Butler EB, Murad F, Pandita TK. Differentiation of Human Induced Pluripotent or Embryonic Stem Cells Decreases the DNA Damage Repair by Homologous Recombination. Stem Cell Reports 2017; 9:1660-1674. [PMID: 29103969 PMCID: PMC5831054 DOI: 10.1016/j.stemcr.2017.10.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 12/16/2022] Open
Abstract
The nitric oxide (NO)-cyclic GMP pathway contributes to human stem cell differentiation, but NO free radical production can also damage DNA, necessitating a robust DNA damage response (DDR) to ensure cell survival. How the DDR is affected by differentiation is unclear. Differentiation of stem cells, either inducible pluripotent or embryonic derived, increased residual DNA damage as determined by γ-H2AX and 53BP1 foci, with increased S-phase-specific chromosomal aberration after exposure to DNA-damaging agents, suggesting reduced homologous recombination (HR) repair as supported by the observation of decreased HR-related repair factor foci formation (RAD51 and BRCA1). Differentiated cells also had relatively increased fork stalling and R-loop formation after DNA replication stress. Treatment with NO donor (NOC-18), which causes stem cell differentiation has no effect on double-strand break (DSB) repair by non-homologous end-joining but reduced DSB repair by HR. Present studies suggest that DNA repair by HR is impaired in differentiated cells. Spontaneous and S-phase-specific chromosome aberrations in differentiated cells Higher frequency of residual γ-H2AX foci after exposure to DNA-damaging agents Higher frequency of cells with 53BP1 and RIF1 co-localization in differentiated cells Higher frequency of cells with a reduced number of RAD51 or BRCA1 foci
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Affiliation(s)
- Kalpana Mujoo
- Department of Radiation Oncology, Weill Cornell Medical College, The Houston Methodist Hospital Research Institute, Houston, TX 77030, USA; Institute of Molecular Medicine, University of Texas Health at Houston, Houston, TX 77030, USA.
| | - Raj K Pandita
- Department of Radiation Oncology, Weill Cornell Medical College, The Houston Methodist Hospital Research Institute, Houston, TX 77030, USA
| | - Anjana Tiwari
- Department of Radiation Oncology, Weill Cornell Medical College, The Houston Methodist Hospital Research Institute, Houston, TX 77030, USA
| | - Vijay Charaka
- Department of Radiation Oncology, Weill Cornell Medical College, The Houston Methodist Hospital Research Institute, Houston, TX 77030, USA
| | - Sharmistha Chakraborty
- Department of Radiation Oncology, Weill Cornell Medical College, The Houston Methodist Hospital Research Institute, Houston, TX 77030, USA
| | - Dharmendra Kumar Singh
- Department of Radiation Oncology, Weill Cornell Medical College, The Houston Methodist Hospital Research Institute, Houston, TX 77030, USA
| | - Shashank Hambarde
- Department of Radiation Oncology, Weill Cornell Medical College, The Houston Methodist Hospital Research Institute, Houston, TX 77030, USA
| | - Walter N Hittelman
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Nobuo Horikoshi
- Department of Radiation Oncology, Weill Cornell Medical College, The Houston Methodist Hospital Research Institute, Houston, TX 77030, USA
| | - Clayton R Hunt
- Department of Radiation Oncology, Weill Cornell Medical College, The Houston Methodist Hospital Research Institute, Houston, TX 77030, USA
| | - Kum Kum Khanna
- QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
| | | | - E Brian Butler
- Department of Radiation Oncology, Weill Cornell Medical College, The Houston Methodist Hospital Research Institute, Houston, TX 77030, USA
| | - Ferid Murad
- The George Washington University, Washington, DC 20037, USA
| | - Tej K Pandita
- Department of Radiation Oncology, Weill Cornell Medical College, The Houston Methodist Hospital Research Institute, Houston, TX 77030, USA.
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19
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Lopez CR, Singh S, Hambarde S, Griffin WC, Gao J, Chib S, Yu Y, Ira G, Raney KD, Kim N. Yeast Sub1 and human PC4 are G-quadruplex binding proteins that suppress genome instability at co-transcriptionally formed G4 DNA. Nucleic Acids Res 2017; 45:5850-5862. [PMID: 28369605 PMCID: PMC5449603 DOI: 10.1093/nar/gkx201] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 03/15/2017] [Indexed: 01/05/2023] Open
Abstract
G-quadruplex or G4 DNA is a non-B secondary DNA structure consisting of a stacked array of guanine-quartets that can disrupt critical cellular functions such as replication and transcription. When sequences that can adopt Non-B structures including G4 DNA are located within actively transcribed genes, the reshaping of DNA topology necessary for transcription process stimulates secondary structure-formation thereby amplifying the potential for genome instability. Using a reporter assay designed to study G4-induced recombination in the context of an actively transcribed locus in Saccharomyces cerevisiae, we tested whether co-transcriptional activator Sub1, recently identified as a G4-binding factor, contributes to genome maintenance at G4-forming sequences. Our data indicate that, upon Sub1-disruption, genome instability linked to co-transcriptionally formed G4 DNA in Top1-deficient cells is significantly augmented and that its highly conserved DNA binding domain or the human homolog PC4 is sufficient to suppress G4-associated genome instability. We also show that Sub1 interacts specifically with co-transcriptionally formed G4 DNA in vivo and that yeast cells become highly sensitivity to G4-stabilizing chemical ligands by the loss of Sub1. Finally, we demonstrate the physical and genetic interaction of Sub1 with the G4-resolving helicase Pif1, suggesting a possible mechanism by which Sub1 suppresses instability at G4 DNA.
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Affiliation(s)
- Christopher R Lopez
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Shivani Singh
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Shashank Hambarde
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Wezley C Griffin
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Jun Gao
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Shubeena Chib
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Yang Yu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Grzegorz Ira
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kevin D Raney
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Nayun Kim
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.,The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
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20
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Chakraborty S, Hunt CR, Hambarde S, Mujoo K, Horikoshi N, Pandita RK, Mattoo A, Teh B, Pandita TK. Abstract 2756: SMARCAD1 depletion enhances hyperthermia-mediated radiosensitization by decreasing resection and enhancing stalled replication forks. Cancer Res 2016. [DOI: 10.1158/1538-7445.am2016-2756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Hyperthermia is the most effective chemo- and radio-sensitizer in use clinically for containing tumor growth. Hyperthermia is proposed to induce degradation of BRCA2, the protein involved in homologous recombination (HR) repair of DNA double strand breaks and, thus sensitizes cells to poly (ADP-ribose) polymerase (PARP)-1 inhibition. We and other laboratories have reported that hyperthermia inhibits DNA damage repair. Since HR includes single-strand annealing, gene conversion and break-induced replication, it is critical for DNA replication during recovery of stalled replication forks, but it is not yet clear how hyperthermia affects these important steps in HR.
Here we report that SMARCAD1 depletion increases hyperthermia induced cell death and chromosome damage in irradiated S-phase cells. Combined SMARCAD1 depletion and hyperthermia treatment decreased repair and recruitment of repairosome proteins to ISce-1 induced DSBs as well as decreased IR-induced repairosome foci formation. This effect was limited to S-phase cells, where homologous recombination is up regulated and the predominant pathway of DSB repair. Hyperthermia decreased the quantity of 5′ single stranded DNA intermediates at endonuclease-generated DNA break sites, an effect that was further decreased by SMARCAD1 depletion. Consistent with these results, simultaneous SMARCAD1 depletion and hyperthermia increased replication fork stalling and affected firing of new replication origins. The results presented here support a mechanism by which SMARCAD1 depletion and hyperthermia mediate radiosensitization through inhibition of the DNA resection step that precedes strand homology search during HR repair of IR-induced DSBs.
Citation Format: Sharmistha Chakraborty, Clayton R. Hunt, Shashank Hambarde, Kalpana Mujoo, Nobuo Horikoshi, Raj K. Pandita, Abid Mattoo, Bin Teh, Tej K. Pandita. SMARCAD1 depletion enhances hyperthermia-mediated radiosensitization by decreasing resection and enhancing stalled replication forks. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2756.
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Dagur RS, Hambarde S, Chandna S. Bryostatin-1 causes radiosensitization of BMG-1 malignant glioma cells through differential activation of protein kinase-Cδ not evident in the non-malignant AA8 fibroblasts. Mol Cell Biochem 2014; 401:49-59. [PMID: 25472878 DOI: 10.1007/s11010-014-2291-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 11/26/2014] [Indexed: 10/24/2022]
Abstract
Bryostatin-1 (bryo-1), a non-phorbol ester, is known to sensitize mammalian cells against certain chemotherapeutic drugs. We assessed its ability to modify radiation response of mammalian cells using Chinese hamster fibroblasts AA8 cells and human malignant glioma BMG-1 cells. In the malignant glioma BMG-1 cell line, bryo-1 pre-treatment significantly enhanced radiation-induced growth inhibition and cytogenetic damage, and further reduced the clonogenic cell survival as compared to cells irradiated at the clinically relevant dose of 2 Gy. PKCδ expression increased significantly when bryo-1 pre-treated BMG-1 glioma cells were irradiated at 2 Gy and induced prolonged ERK-1/2 activation associated with p21 overexpression. Silencing PKCδ resulted in inhibition of bryo-1-induced radiosensitization. In contrast, bryo-1 failed to alter radiosensitivity (cell survival; growth inhibition; cytogenetic damage) or activate ERK1/2 pathway in the AA8 fibroblasts despite PKCδ phosphorylation at its regulatory (Y155) domain, indicating alternate mechanisms in these non-malignant cells as compared to the glioma cells. This study suggests that bryo-1 may effectively enhance the radiosensitivity of malignant cells and warrants further in-depth investigations to evaluate its radiosensitizing potential in various cell types.
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Affiliation(s)
- Raghubendra Singh Dagur
- Natural Radiation Response Mechanisms Group, Division of Radiation Biosciences, Institute of Nuclear Medicine & Allied Sciences, Brig. S K Mazumdar Road, Timarpur, Delhi, 110054, India
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Hambarde S, Yennamalli RM, Subbarao N, Chandna S. Predictive inference on cytoplasmic and mitochondrial thioredoxin peroxidases in the highly radioresistant Lepidopteran insect Spodoptera frugiperda. Bioinformation 2010; 4:399-404. [PMID: 20975889 PMCID: PMC2951639 DOI: 10.6026/97320630004399] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 12/28/2009] [Accepted: 02/08/2010] [Indexed: 11/23/2022] Open
Abstract
Lepidopteran insects show remarkable resistance to radiation and chemical stress than insects of other orders. Despite this, the antioxidant
machinery of insects of this order is poorly understood. Recently we demonstrated the significance of cytoplasmic NOS and a stronger
mitochondrial antioxidant enzyme system in the stress-resistance of Lepidopteran insects. In the present study, we hypothesize two
thioredoxin peroxidase orthologues (Sf-TPx1 and Sf-TPx2) in Lepidopteran insect Spodoptera frugiperda and demonstrate their
structural/functional features important for cellular antioxidant activity and stress resistance. Results show a higher mitochondrial
localization score (WoLFPSORT) of Sf-TPx2 (mitochondria-18.0, cytoplasm-7.0, nucleus-4.0) than its Drosophila orthologue Jafrac2
(secretory-30.0; mitochondria/nucleus/cytoplasm-no signal), which is important for antioxidant activity, and a higher cytoplasmic
localization score of Sf-TPx1 (mitochondria-no signal; cytoplasm-22.0; nucleus-3.5) than the Drosophila Jafrac1 (mitochondria-17; nucleus-
11; cytoplasm-no signal). Structural modeling data show certain motifs present in Jafrac1 and Jafrac2 that affect active site conformation
and separate cysteine residues at distances not suitable for disulphide bridge formation (5.21Å; 5.73Å). These motifs are absent in Sf-TPx1
and Sf-TPx2, yielding shorter distance (2.01Å; 2.05Å) between the cysteine residues suitable for disulphide bridge formation. Taken
together, the disulphide bridge as well as mitochondrial and cytoplasmic localization are crucial for peroxidatic activity of TPx's. Therefore,we hypothesize
that the Spodoptera TPx's offer potentially stronger anti-oxidant activity than that of Drosophila orthologues, and may
contribute in the high radioresistance of Lepidopteran insects.
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Affiliation(s)
- Shashank Hambarde
- Natural Radiation Response Mechanisms Group, Division of Radiation Biosciences, Institute of Nuclear Medicine and Allied Sciences, Brig. S.K. Mazumdar Road, Delhi -110054, India
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Abstract
The RAS protein controls signaling pathway are major player in cell growth, its regulation and malignant transformation. Any activation in RAS brings alteration in upstream or downstream signaling component. Activating mutation in RAS is found in approximately 30% of human cancer. RAS plays essential role in tumor maintenance and is therefore an appropriate target for anticancer therapy. Among the anti-RAS strategies that are under evaluation in the clinic are pharmacologic inhibitors designed to prevent: (1) association with the plasma membrane (prenylation and post prenylation inhibitors). (2) Downstream signaling (kinase inhibitor), (3) upstream pathway (kinase inhibitor and monoclonal antibody), (4) Expression of RAS or other component of pathway (siRNA and antisense oligonucleotide). Several of these new therapeutic agents are showing promising result in the clinic and many more are on the way. Here, we review the current status and new hopes for targeting RAS as an anticancer drug.
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Affiliation(s)
- Nandita Saxena
- Department of Radiation Biology and Radioprotectors, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
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