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Perlov NM, Shah SS, Bluj J, Urdang ZD, Chiffer RC. The Effect of Postoperative Naloxone in Certain Otolaryngologic Surgeries. Otolaryngol Head Neck Surg 2024; 170:1289-1295. [PMID: 38123881 DOI: 10.1002/ohn.625] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/12/2023] [Accepted: 12/02/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE To evaluate the association of postoperative naloxone with the development of new substance use disorder (SUD), overdose, and death within 6 months of otolaryngologic surgery. STUDY DESIGN Retrospective cohort database study on TriNetX. METHODS Adult patients who underwent tonsil surgery (noncancerous), thyroid/parathyroid, septorhinoplasty, otology/neurotology, sinus/anterior skull base, and head and neck cancer surgeries between January 2003 and April 2023. Patients were excluded if they had an instance of SUD or overdose recorded in their charts prior to surgery, or had undergone another surgery within that 6-month time frame. We hypothesized that patients prescribed naloxone postoperatively would have decreased odds for experiencing new SUD, overdose, and/or death within 6 months of surgery compared to patients who did not receive naloxone. P < .01 was considered statistically significant. RESULTS There were 2,305,655 patients in this study. The average age was 36.7 ± 19.5 years old, with 46% female patients. Before matching, cohorts showed equivocal odds for developing new SUD, increased odds for overdose, and mixed odds for dying. After matching for demographic variables and comorbidities such as other substance use, opioid use for other pathologies, and psychiatric conditions, these effects diminished (P > .01). CONCLUSION Our results suggest that postoperative naloxone may not significantly affect development of new SUD and incident overdose and death in certain otolaryngologic surgeries after controlling for prior SUD and psychiatric conditions. Clinicians should be aware of these comorbidities when considering their postoperative pain management protocol, which may or may not include naloxone.
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Affiliation(s)
- Natalie M Perlov
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Sohan S Shah
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Joann Bluj
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Zachary D Urdang
- Department of Otolaryngology-Head and Neck Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA
| | - Rebecca C Chiffer
- Department of Otolaryngology-Head and Neck Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA
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Tekumalla S, Perlov NM, Gokhale S, Awosanya S, Urdang ZD, Croce J, Bixler A, Willcox TO, Chiffer RC, Fitzgerald D. Evaluation of Subjective Tinnitus Severity and Distortion Product Otoacoustic Emissions and Extended High-Frequency Audiometry. Otolaryngol Head Neck Surg 2024. [PMID: 38639322 DOI: 10.1002/ohn.777] [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] [Received: 10/08/2023] [Revised: 01/25/2024] [Accepted: 02/24/2024] [Indexed: 04/20/2024]
Abstract
OBJECTIVE Tinnitus is a multifactorial phenomenon with quality-of-life detriments for those affected by it. We aim to establish a relationship between subjective tinnitus severity with objective audiometric data in the extended high frequency (EHF) from 9 to 16 khz and with distortion product otoacoustic emissions (DPOAE). We hypothesize that severe subjective tinnitus as measured by the Tinnitus Handicap Inventory (THI) does not correlate with increased hearing thresholds in the EHF range. STUDY DESIGN Prospective. SETTING Single Tertiary Care Center. METHODS Patients identified with tinnitus and normal hearing thresholds within standard frequency range (250-8000 Hz) were consented for participation. Those with underlying otologic disease, trauma, radiotherapy, or ototoxic drug use were excluded. The THI questionnaire was given to eligible patients and audiometric test results were collected. THI scores were categorized by severity groups. An n = 20 to 30 was determined to have an effect size of 0.7 with a significance level of P = .05. RESULTS THI and audiometric data were collected for 38 patients and categorized into mild (n = 18, 47.4%), moderate (n = 8, 21.1%), slight (n = 7, 18.4%), and severe (n = 5, 13.2%) tinnitus severity groups. Mean THI score was 32.3 ± 19.6 with a statistically significant difference in scores by assigned THI severity group (P < .01). There were no significant differences or linear relationship among hearing thresholds in EHF range or DPOAE stratified by subjective tinnitus group (P = .49, r2 = 0.10) CONCLUSION: Subjective tinnitus severity is not predictive of audiometric outcomes. This finding can be used as a counseling tool to help tinnitus patients manage symptoms, expectations, and overall treatment outcomes.
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Affiliation(s)
- Sruti Tekumalla
- Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Natalie M Perlov
- Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Saket Gokhale
- Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Samiat Awosanya
- Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Zachary D Urdang
- Thomas Jefferson Hospital Department of Otolaryngology-Head and Neck Surgery, Philadelphia, Pennsylvania, USA
| | - Julia Croce
- Thomas Jefferson Hospital Department of Otolaryngology-Head and Neck Surgery, Philadelphia, Pennsylvania, USA
| | - Anna Bixler
- Thomas Jefferson Hospital Department of Otolaryngology-Head and Neck Surgery, Philadelphia, Pennsylvania, USA
| | - Thomas O Willcox
- Thomas Jefferson Hospital Department of Otolaryngology-Head and Neck Surgery, Philadelphia, Pennsylvania, USA
| | - Rebecca C Chiffer
- Thomas Jefferson Hospital Department of Otolaryngology-Head and Neck Surgery, Philadelphia, Pennsylvania, USA
| | - Dennis Fitzgerald
- Thomas Jefferson Hospital Department of Otolaryngology-Head and Neck Surgery, Philadelphia, Pennsylvania, USA
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Perlov NM, Li M, Patel J, Kumar AT, Urdang ZD, Willcox TO, Parkes W, Chiffer RC. Cognitive and language outcomes for pediatric hearing loss with otologic surgery. Int J Pediatr Otorhinolaryngol 2024; 178:111889. [PMID: 38359620 DOI: 10.1016/j.ijporl.2024.111889] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/28/2024] [Accepted: 02/05/2024] [Indexed: 02/17/2024]
Abstract
OBJECTIVES To test the hypothesis that surgical otologic intervention for any type of pediatric hearing loss decreases the odds for incident adverse cognitive and linguistic developmental outcomes. STUDY DESIGN Retrospective cohort database study. METHODS Electronic medical record data from the TriNetX Research Network were queried for children with congenital, sensorineural, conductive, and mixed hearing loss (HL) between ages 0 and 5 years. Patients were further stratified by presence (HL + surgery) or absence (HL-surgery) of surgical intervention at any point following diagnosis, including cochlear implantation, tympanoplasty with or without mastoidectomy, and tympanostomy. Primary outcomes were defined as odds for new adverse cognitive or linguistic outcomes at any point given HL treatment status [odds ratio with 95% confidence interval, (OR; 95%CI, p-value)]. Cohorts were balanced using propensity-score matching (PSM) based on US census-defined demographics and clinically relevant congenital conditions. RESULTS Of 457,636 total patients included in the study, 118,576 underwent surgery (HL + surgery cohort) and 339,060 did not (HL-surgery). In matched cohorts, surgical otologic intervention significantly decreased the odds of developing cognitive disorders including scholastic, motor, psychological developmental disorders, and pervasive developmental delays (p < 0.01). CONCLUSIONS Surgical interventions for treatment of pediatric HL including cochlear implantation, tympanoplasty with or without mastoidectomy, and tympanostomy should be considered as they may prevent delays in development.
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Affiliation(s)
| | - Marwin Li
- Sidney Kimmel Medical College, Philadelphia, PA, USA
| | - Jena Patel
- Department of Otolaryngology - Head and Neck Surgery, Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | - Ayan T Kumar
- Department of Otolaryngology - Head and Neck Surgery, Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | - Zachary D Urdang
- Department of Otolaryngology - Head and Neck Surgery, Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | - Thomas O Willcox
- Department of Otolaryngology - Head and Neck Surgery, Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | | | - Rebecca C Chiffer
- Department of Otolaryngology - Head and Neck Surgery, Thomas Jefferson University Hospital, Philadelphia, PA, USA
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Li M, Perlov NM, Patel J, Amin D, Kumar A, Urdang ZD, Willcox TO, Chiffer RC. Association of Smoke and Nicotine Product Consumption With Sensorineural Hearing Loss: A Population-Level Analysis. Otol Neurotol 2023; 44:1094-1099. [PMID: 37853788 DOI: 10.1097/mao.0000000000004031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
OBJECTIVE To test the hypothesis that use of cigarettes or other products with either cigarette-like smoke profile or high nicotine content by young populations increases the odds of developing sensorineural hearing loss (SNHL). STUDY DESIGN Retrospective cohort study. SETTING TriNetX US Collaborative Network (2003-2022). PATIENTS Approximately 3.6 million patients at least 18 years old. INTERVENTION None. MAIN OUTCOME MEASURES The primary outcome of interest was diagnosis of SNHL, defined using medical billing codes ( International Classification of Diseases, Tenth Revision , Current Procedural Terminology , etc.). Cohort inclusion criteria included electronic health record entry after 2003, age 18 to 54 or 55+ years at index, and status of cigarette, noncigarette nicotine, or cannabis use. Covariates were controlled via 1:1 propensity score matching for SNHL-related conditions, including diabetes mellitus and ischemic diseases. Odds for developing SNHL were calculated against control subjects aged 18 to 54 years who have no record of nicotine/cannabis use. RESULTS Odds for developing SNHL are higher for people 18 to 54 years old who use any nicotine product (odds ratio [95% confidence interval], 5.91 [5.71-6.13]), cigarettes only (4.00 [3.69-4.33]), chewing tobacco only (9.04 [7.09-11.63]), or cannabis only (3.99 [3.60-4.44]) compared with control. People 55+ years old who use no products also showed increased odds for SNHL (4.73 [4.63-4.85]). CONCLUSIONS Both nicotine and smoke exposure seem to be strongly associated with increased odds for developing SNHL, with chewing tobacco having the strongest association.
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Affiliation(s)
- Marwin Li
- Sidney Kimmel Medical College, Thomas Jefferson University
| | | | - Jena Patel
- Department of Otolaryngology, Thomas Jefferson University Hospital, Philadelphia Pennsylvania
| | - Dev Amin
- Department of Otolaryngology, Thomas Jefferson University Hospital, Philadelphia Pennsylvania
| | - Ayan Kumar
- Department of Otolaryngology, Thomas Jefferson University Hospital, Philadelphia Pennsylvania
| | - Zachary D Urdang
- Department of Otolaryngology, Thomas Jefferson University Hospital, Philadelphia Pennsylvania
| | - Thomas O Willcox
- Department of Otolaryngology, Thomas Jefferson University Hospital, Philadelphia Pennsylvania
| | - Rebecca C Chiffer
- Department of Otolaryngology, Thomas Jefferson University Hospital, Philadelphia Pennsylvania
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Khanna O, D'Souza G, Hattar-Medina E, Karsy M, Chiffer RC, Willcox TO, Farrell CJ, Evans JJ. A Comparison of Outcomes Using Combined Intra- and Extradural versus Extradural-Only Repair of Tegmen Defects. J Neurol Surg B Skull Base 2023; 84:136-142. [PMID: 36895816 PMCID: PMC9991520 DOI: 10.1055/a-1757-0328] [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] [Received: 06/08/2021] [Accepted: 01/28/2022] [Indexed: 10/19/2022] Open
Abstract
Objective Tegmen tympani or tegmen mastoideum defects involve dehiscence of the temporal bone that can be a source of cerebrospinal fluid (CSF) otorrhea. Herein, we compare a combined intra-/extradural repair strategy with an extradural-only repair as it pertains to surgical and clinical outcomes. Design A retrospective review from our institution was performed of patients with tegmen defects requiring surgical intervention. Participants Patients with tegmen defects who underwent surgery (combined transmastoid and middle fossa craniotomy) for repair of tegmen defects between 2010 and 2020 were inclined in this study. Results A total of 60 patients with 40 intra-/extradural (mean follow-up time: 1,060 ± 1,103 days) and 20 extradural-only (mean follow-up time: 519 ± 369 days) repairs were identified. No major differences in demographic factors or presenting symptoms were identified between the two cohorts. There was no difference in hospital length of stay between the two patient cohorts (mean: 4.15 vs. 4.35 days, p = 0.8). In the extradural-only repair technique, synthetic bone cement was more frequently used (100 vs. 7.5%, p < 0.01), whereas in the combined intra-/extradural repair, synthetic dural substitute was used more often (80 vs. 35%, p < 0.01), with similar successful surgical outcomes achieved. Despite disparities in the techniques and materials used for repair, there were no differences in complication rates (wound infection, seizures, and ossicular fixation), 30-day readmission rates, or persistent CSF leak between the two treatment cohorts. Conclusion The results of this study suggest no difference in clinical outcomes between combined intra-/extradural versus extradural-only repair of tegmen defects. A simplified extradural-only repair strategy can be effective, and may reduce the morbidity of intradural reconstruction (seizures, stroke, and intraparenchymal hemorrhage).
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Affiliation(s)
- Omaditya Khanna
- Department of Neurological Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States
| | - Glen D'Souza
- Department of Otolaryngology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States
| | - Ellina Hattar-Medina
- Department of Neurological Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States
| | - Michael Karsy
- Department of Neurological Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States
| | - Rebecca C Chiffer
- Department of Otolaryngology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States
| | - Thomas O Willcox
- Department of Otolaryngology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States
| | - Christopher J Farrell
- Department of Neurological Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States
| | - James J Evans
- Department of Neurological Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States
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Chiffer RC, Schwab RJ, Keenan BT, Borek RC, Thaler ER. Volumetric MRI analysis pre- and post-Transoral robotic surgery for obstructive sleep apnea. Laryngoscope 2015; 125:1988-95. [PMID: 25891205 DOI: 10.1002/lary.25270] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Revised: 01/27/2015] [Accepted: 02/25/2015] [Indexed: 11/11/2022]
Abstract
OBJECTIVES/HYPOTHESIS To quantitatively measure volumetric changes in upper airway soft tissue structures using magnetic resonance imaging (MRI) pre- and post transoral robotic surgery for obstructive sleep apnea (OSA-TORS). STUDY DESIGN Prospective, nonrandomized, institutional board-approved study. METHODS Apneics undergoing OSA-TORS, which included bilateral posterior hemiglossectomy with limited pharyngectomy and uvulopalatopharyngoplasty, had upper airway MRIs pre- and postoperatively. Changes (percent and absolute values) in upper airway and surrounding soft tissue volumes were calculated. We assessed whether there were significant volumetric changes and if changes correlated with apnea-hypopnea index (AHI) changes. RESULTS Nineteen MRIs and 18 polysomnograms were analyzed pre- and postoperation. Total airway volume increased by 19.4% (P = 0.030). Soft palate and tongue volumes decreased by 18.3% (P = 0.002) and 5.8% (P = 0.013), respectively. Retropalatal and total lateral wall volumes decreased by 49.8% (P = 0.0001) and 17.9% (P = 0.008), respectively. Changes in other structures were not significant. Eleven patients had surgical success, with a mean AHI decrease of 52.9; six were nonsuccesses with a mean AHI decrease of 4.5 (P =0.006). Decreased retropalatal lateral wall volume correlated with decreased AHI. CONCLUSION Airway, tongue, soft palate, and lateral wall volumes change significantly after OSA-TORS. Changes in the volume of the lateral walls correlated with changes in AHI. Volumetric upper airway MRI may be a helpful tool to better understand reasons for surgical success. LEVEL OF EVIDENCE 4.
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Affiliation(s)
- Rebecca C Chiffer
- Department of Otorhinolaryngology-Head and Neck Surgery, Hospital of the University of Pennsylvania, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, U.S.A
| | - Richard J Schwab
- Department of Medicine, Division of Sleep Medicine, Pulmonary, Allergy and Critical Care Division, Penn Sleep Center, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, U.S.A
| | - Brendan T Keenan
- Perelman School of Medicine at the University of Pennsylvania, Division of Sleep Medicine, Center for Sleep and Circadian Neurobiology, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, U.S.A
| | - Ryan C Borek
- Department of Otorhinolaryngology-Head and Neck Surgery, Hospital of the University of Pennsylvania, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, U.S.A
| | - Erica R Thaler
- Department of Otorhinolaryngology-Head and Neck Surgery, Perelman School of Medicine at the University of Pennsylvania, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, U.S.A
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Chiffer RC, Borek RC, Schwab R, Thaler ER. Predicting Success of Transoral Robotic Surgery for OSA Using Preoperative Sleep Endoscopy and MRI Analysis. Otolaryngol Head Neck Surg 2014. [DOI: 10.1177/0194599814541627a328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objectives: Determine the relationship between surgical success and both preoperative drug-induced sleep endoscopy (DISE) airway caliber changes and volumetric magnetic resonance imaging (MRI) in patients with obstructive sleep apnea (OSA) undergoing transoral robotic assisted posterior glossectomy and uvulopalatopharyngoplasty (OSA-TORS). Methods: From 2009 to present, as part of a nonrandomized prospective trial, patients with OSA undergoing OSA-TORS had preoperative DISE and pre- and postoperative volumetric MRI of the upper airway. Quantitative analysis of the endoscopy and MRI were compared with surgical success based upon pre- and postoperative polysomnogram, with success defined as postoperative apnea-hypopnea index (AHI) <20 and AHI decrease ≥50%. Preoperative MRI volumes were also compared against DISE changes. Results: Thirty-five apneics undergoing OSA-TORS underwent DISE, 21 received MRIs. DISE data showed that patients with surgical success had a smaller percentage decrease in overall airway collapse in the retroepiglottic ( P = .045) and retroglottic regions ( P = .08) compared with nonsuccesses. Larger preoperative MRI retroglottic airway volumes correlated with increased retroglottic ( P = .05) and retroepiglottic ( P = .03) lateral airway collapse on DISE, however, differences in pre- and postoperative MRI airway volumes did not correlate with surgical success. Conclusions: Larger retroglottic airway volume on MRI correlated with greater lateral airway collapse during DISE, but not with surgical success. Successes after OSA-TORS had significantly smaller airway collapse in the retroepiglottic regions than nonsuccesses during DISE, possibly due to better baseline muscle tone, allowing for better ability to benefit from the relatively small change in airway volume that OSA-TORS provides. Preoperative quantitative DISE could be used to identify patients more likely to succeed after OSA-TORS.
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Rodriguez-Collazo P, Snyder SK, Chiffer RC, Bressler EA, Voss TC, Anderson EP, Genieser HG, Smith CL. cAMP signaling regulates histone H3 phosphorylation and mitotic entry through a disruption of G2 progression. Exp Cell Res 2008; 314:2855-69. [PMID: 18644368 DOI: 10.1016/j.yexcr.2008.06.022] [Citation(s) in RCA: 5] [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] [Received: 03/01/2008] [Revised: 06/28/2008] [Accepted: 06/30/2008] [Indexed: 01/06/2023]
Abstract
cAMP signaling is known to have significant effects on cell growth, either inhibitory or stimulatory depending on the cell type. Study of cAMP-induced growth inhibition in mammalian somatic cells has focused mainly on the combined role of protein kinase A (PKA) and mitogen-activated protein (MAP) kinases in regulation of progression through the G1 phase of the cell cycle. Here we show that cAMP signaling regulates histone H3 phosphorylation in a cell cycle-dependent fashion, increasing it in quiescent cells but dramatically reducing it in cycling cells. The latter is due to a rapid and dramatic loss of mitotic histone H3 phosphorylation caused by a disruption in G2 progression, as evidenced by the inhibition of mitotic entry and decreased activity of the CyclinB/Cdk1 kinase. The inhibition of G2 progression induced through cAMP signaling is dependent on expression of the catalytic subunit of PKA and is highly sensitive to intracellular cAMP concentration. The mechanism by which G2 progression is inhibited is independent of both DNA damage and MAP kinase signaling. Our results suggest that cAMP signaling activates a G2 checkpoint by a unique mechanism and provide new insight into normal cellular regulation of G2 progression.
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Affiliation(s)
- Pedro Rodriguez-Collazo
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Rodriguez-Collazo P, Snyder SK, Chiffer RC, Zlatanova J, Leuba SH, Smith CL. cAMP signaling induces rapid loss of histone H3 phosphorylation in mammary adenocarcinoma-derived cell lines. Exp Cell Res 2007; 314:1-10. [PMID: 17950276 DOI: 10.1016/j.yexcr.2007.09.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Revised: 09/06/2007] [Accepted: 09/18/2007] [Indexed: 11/26/2022]
Abstract
The phosphorylation of histone H3 is known to play a role in regulation of transcription as well as preparation of chromosomes for mitosis. Various signaling cascades induce H3 phosphorylation, particularly at genes activated by these pathways. In this study, we show that signaling can also have the opposite effect. Activators of cAMP signaling induce a rapid and potent loss of H3 phosphorylation. This effect is not mediated through a cAMP metabolite since a membrane-permeable form of AMP had no effect on H3 phosphorylation and a phosphodiesterase-resistant cAMP analog efficiently reduced it. cAMP is also the likely regulator of H3 phosphorylation under physiological conditions since only supra-pharmacological doses of cGMP induce the loss of H3 phosphorylation. The loss of phosphorylation is specific for histone H3 since we do not observe drastic losses in total phosphorylation of other histones. In addition, other H3 modifications are unaffected with the exception of lysine 9 methylation, which is elevated. Analysis of cell growth and cell cycle shows that cAMP signaling inhibits cell growth and arrests cells at both G1 and G2/M. Similar effects of cAMP signaling on H3 phosphorylation are observed in a variety of mammary adenocarcinoma-derived cell lines. In syngeneic human breast-derived cell lines, one diploid and non-transformed, the other derived from a ductal carcinoma, the loss of H3 phosphorylation is significantly more sensitive to cAMP concentration in the transformed cell line.
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Affiliation(s)
- Pedro Rodriguez-Collazo
- Signal Transduction Group, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20895, USA
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