13 results on '"Stieg MR"'
Search Results
2. Fractionated radiotherapy and radiosurgery in acromegaly: analysis of 352 patients from the German Acromegaly Registry.
- Author
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Knappe UJ, Petroff D, Quinkler M, Schmid SM, Schöfl C, Schopohl J, Stieg MR, and Tönjes A
- Subjects
- Adult, Cohort Studies, Combined Modality Therapy, Dose Fractionation, Radiation, Female, Follow-Up Studies, Germany, Humans, Insulin-Like Growth Factor I analysis, Male, Middle Aged, Registries, Remission Induction, Retrospective Studies, Treatment Outcome, Young Adult, Acromegaly radiotherapy, Acromegaly surgery, Adenoma radiotherapy, Adenoma surgery, Growth Hormone-Secreting Pituitary Adenoma radiotherapy, Growth Hormone-Secreting Pituitary Adenoma surgery, Radiosurgery methods
- Abstract
Background: If biochemical control of acromegaly is not achieved by operation and medication, radiotherapy may be indicated., Objective: To describe fractionated radiotherapy (FRT) and stereotactic radiosurgery (SRS) regarding excess of IGF-1 and pituitary function., Design and Methods: A retrospective analysis of 352 patients (4126 patient-years) from the German Acromegaly Registry was performed. Follow-up was 1.0-45.1 years after radiotherapy. Therapeutic success was defined by low or normal IGF-1 according to center-specific reference ranges without (= remission) or on (= controlled disease) suppressive medication., Results: Time between radiotherapy and last follow-up was 13.0 ± 8.2 years for FRT (n = 233) and 8.9 ± 5.0 years for SRS (n = 119, P < 0.001). Median (IQR) basal growth hormone before radiotherapy was 6.3 (2.9-16.2) ng/mL for FRT and 3.5 (1.8-6.9) ng/mL for SRS (P < 0.001). Mean time in uncontrolled state was 3.0 years after FRT and 2.1 years after SRS (95% CI for the difference is 0.1 to 1.6 years, P = 0.021). The 10-year calculated remission rate was 48% for FRT and 52% for SRS (95% CI for the difference is -18 to 26% age points, P = 0.74) and the respective controlled disease rate was 23 and 26%. The odds ratio for adrenocorticotropic or thyreotropic insufficiency was 0.54 (95% CI: 0.30-1.00, P = 0.049) in SRS compared to FRT patients., Conclusion: Both after FRT and SRS about 75% of patients with acromegaly are in remission or controlled after 10 years. A slightly faster achievement of target values was observed after SRS. The rate of pituitary insufficiency in FRT patients is significantly higher.
- Published
- 2020
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3. Clinical score system in the treatment of Cushing's disease: failure to identify discriminative variables from the German Cushing's Registry.
- Author
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Stieg MR, Auer MK, Berr C, Fazel J, Reincke M, Zopp S, Yassouridis A, and Stalla GK
- Subjects
- Cushing Syndrome urine, Female, Humans, Hydrocortisone urine, Male, Middle Aged, Multivariate Analysis, Pituitary ACTH Hypersecretion urine, Quality of Life, Registries statistics & numerical data, Cushing Syndrome diagnosis, Pituitary ACTH Hypersecretion diagnosis
- Abstract
Purpose: To develop a multidimensional and integrated clinical scoring instrument, that encompasses, summarizes and weights appropriately the desired clinical benefits of a treatment for Cushing's disease (CD)., Methods: A panel of 42 variables potentially relevant to the clinical course of CD was predefined by endocrinology experts taking into account relevant literature. Variables as well as biochemical disease activity assessed as urinary free cortisol (UFC) levels were evaluated at baseline and at least after 12 months in patients treated between 2012 and 2016 in two Munich-based academic centres of the German Cushing's Registry. The primary endpoint was the identification of variables whose changes from baseline to follow-up visit(s) could characterize well biochemical cured from not cured patients after 12 months., Results: Ninety nine patients with at least two consecutive visits were enrolled. Biochemical data were available for 138 visit-pairs among which UFC was not controlled in 48 (34.8%) and controlled in 90 (65.2%) first visits. In 41 (29.7%) consecutive visits (visit-pairs) changes in biochemical activity categories was observed between visits; concretely: in 17 (12.3%) consecutive visits changing from previously controlled to not controlled, and in 24 (17.4%) from uncontrolled to controlled biochemical activity. Multivariate statistical analyses (especially analyses of variance) based on data of the 138 visit-pairs were performed in order to proof possible effects of biochemical activity on clinical benefits. However, in none of the considered 42 variables corresponding to quality of life-dimensions, laboratory, anthropometric, musculo-skeletal or other clinical areas any statistically significant differences between different categories of biochemical activity were observed., Conclusion: It was not possible to provide clinical key parameters in our population of patients with CD discriminating biochemical cured from non-cured patients and to construct a clinical scoring system reflecting clinical treatment benefits.
- Published
- 2019
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4. Primary Empty Sella Syndrome and the Prevalence of Hormonal Dysregulation.
- Author
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Auer MK, Stieg MR, Crispin A, Sievers C, Stalla GK, and Kopczak A
- Subjects
- Empty Sella Syndrome complications, Empty Sella Syndrome diagnostic imaging, Empty Sella Syndrome physiopathology, Endocrine System Diseases epidemiology, Endocrine System Diseases etiology, Estradiol analysis, Female, Humans, Hydrocortisone analysis, Hypopituitarism diagnosis, Incidental Findings, Insulin-Like Growth Factor I analysis, Magnetic Resonance Imaging methods, Male, Neuroradiography instrumentation, Pituitary Gland physiopathology, Prevalence, Prolactin analysis, Testosterone analysis, Thyroxine analysis, Empty Sella Syndrome epidemiology, Endocrine System Diseases blood, Hypopituitarism blood, Hypopituitarism epidemiology
- Abstract
Background: Empty sella is the neuroradiological or pathological finding of an apparently empty sella turcica containing no pituitary tissue. The prevalence of primary empty sella, i.e., empty sella without any discernible cause, is not precisely known; estimates range from 2% to 20%. Technical advances in neuroradiology have made empty sella an increasingly common incidental finding. It remains unclear whether, and to what extent, asymptomatic adult patients with an incidentally discovered empty sella should undergo diagnostic testing for hormonal disturbances., Methods: To answer this question, the authors carried out a systematic search in the PubMed and Web of Science databases for publications that appeared in the period 1995-2016 and that contained the search term "empty sella" (registration: PROSPERO 2015: CRD42015024550)., Results: The search yielded 1282 hits. After the exclusion of duplicates, pediatric reports, case reports, and veterinary studies, 120 publications on primary empty sella syndrome (PES) were identified. 4 of these dealt with the prevalence of pituitary insufficiency in patients with PES as an incidental finding. Among patients with PES, the relative frequency of pituitary insufficiency in the pooled analysis was 52% (95% confidence interval [38; 65])., Conclusion: The data on PES as an incidental finding are too sparse to enable any evidence-based recommendation on the potential indications for hormone testing or its nature and extent. We advise basic neuroendocrinological testing (fasting cortisol, free thyroxine [fT4], estradiol or testosterone, insulin-like growth factor 1 [IGF-1], and prolactin). There is an unexplained discrepancy between the reported high prevalence of pituitary insufficiency among persons with PES and its low prevalence in epidemiologic studies. We suspect that the former may be high because of selection bias in the publications that we reviewed, or else the latter may be erroneously low.
- Published
- 2018
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5. De-masking oxytocin-deficiency in craniopharyngioma and assessing its link with affective function.
- Author
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Gebert D, Auer MK, Stieg MR, Freitag MT, Lahne M, Fuss J, Schilbach K, Schopohl J, Stalla GK, and Kopczak A
- Subjects
- Adult, Anxiety psychology, Depression psychology, Female, Humans, Hypopituitarism metabolism, Hypothalamus metabolism, Male, Middle Aged, Oxytocin analysis, Pituitary Neoplasms metabolism, Prospective Studies, Affective Symptoms metabolism, Craniopharyngioma metabolism, Oxytocin metabolism
- Abstract
Despite the high prevalence of panhypopituitarism and diabetes insipidus in patients with craniopharyngioma (CP), little is known about the functioning of the neuropeptide oxytocin in these patients. This is of special interest as tumor-associated lesions often impair sites critical for oxytocin production and release, and affective dysfunction in CP links with elsewhere reported prosocial, antidepressant and anxiolytic oxytocin effects. Using a prospective study-design, we tested whether oxytocin is reduced in CP-patients, and whether altered oxytocin levels account for affective and emotional dysfunction. 26 adult CP-patients and 26 healthy controls matched in sex and age underwent physical exercise, a stimulus previously shown to induce oxytocin release. Baseline and stimulated salivary oxytocin levels, as well as empathy, depression and anxiety scores were measured. Results showed that patients overall did not present with lower baseline oxytocin levels than controls (F[1,30]=0.21, p=0.649), but baseline oxytocin levels were indeed reduced in patients with hypothalamic damage, as assessed by MRI-based grading (F[2,9.79]=4.54, p=0.040). In response to exercise-induced stimulation, all CP-patients showed a blunted oxytocin-release compared to controls (F[1,30]=9.36, p=0.005). DI was not associated with oxytocin levels. Regarding affective function, unexpectedly, higher baseline oxytocin was related to higher trait anxiety (b=2.885, t(43)=2.421, p=0.020, CI[.478; 5.292]); the positive link with higher depression failed to reach statistical significance (b=1.928, t(43)=1.949, p=0.058, CI[-0.070; 3.927]). A blunted oxytocin-release was linked with higher state anxiety (b=-0.133, t(43)=-2.797, p=0.008, CI[-0.230; -0.037]). Empathy was not associated with oxytocin measures. In conclusion, we observed reduced baseline oxytocin levels only in CP-patients with hypothalamic damage. Exercise-induced stimulation de-masked an oxytocin-deficiency in all CP-patients. Baseline oxytocin levels and stimulated OT-responses might have different effects on affective function, which should be considered in future substitution paradigms., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2018
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6. Somatic USP8 mutations are frequent events in corticotroph tumor progression causing Nelson's tumor.
- Author
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Pérez-Rivas LG, Theodoropoulou M, Puar TH, Fazel J, Stieg MR, Ferraù F, Assié G, Gadelha MR, Deutschbein T, Fragoso MC, Kusters B, Saeger W, Honegger J, Buchfelder M, Korbonits M, Bertherat J, Stalla GK, Hermus AR, Beuschlein F, and Reincke M
- Subjects
- Adrenocorticotropic Hormone blood, Adult, Carcinogenesis metabolism, Cohort Studies, Corticotrophs physiology, Female, Humans, Male, Nelson Syndrome blood, Nelson Syndrome surgery, Retrospective Studies, Young Adult, Carcinogenesis genetics, Disease Progression, Endopeptidases genetics, Endosomal Sorting Complexes Required for Transport genetics, Mutation genetics, Nelson Syndrome genetics, Ubiquitin Thiolesterase genetics
- Abstract
Objective: Somatic mutations in the ubiquitin-specific protease 8 ( USP8 ) gene are frequent in corticotroph tumors causing Cushing's disease (CD). Corticotroph tumor progression, the so-called Nelson's syndrome (NS), is a potentially life-threatening complication of bilateral adrenalectomy in patients with refractory CD that is caused by the development of an ACTH-secreting tumor of the pituitary gland. Whether USP8 alterations are also present in progressive Nelson's tumors has not been studied in detail so far., Design and Methods: Retrospective, multicenter study involving tumors from 33 patients with progressive corticotroph tumors (29 females) and screening for somatic mutations on the mutational hotspot of the USP8 gene in the exon 14 with Sanger sequencing., Results: Fifteen out of 33 tumors (45%) presented with a mutation in the exon 14 of USP8 , with c.2159C>A (p.Pro720Gln) being the most frequent (9/33), followed by c.2155_2157delTCC (p.Ser718del, 4/33) and c.2152T>C (p.Ser718Pro, 2/33). This prevalence is similar to that previously reported for CD. Mutations were found exclusively in females. Other variables, such as age at diagnosis with NS, body mass index, hyperpigmentation, visual field defects, adenoma size or mortality, did not significantly differ between patients with wild-type and mutant tumors. Patients with USP8 mutant tumors exhibited higher levels of plasma ACTH after surgery (median: 640 vs 112 pg/mL, P = 0.03). No differences were observed in ACTH normalization (<50 pg/mL) and tumor control after surgery for Nelson's tumor., Conclusion: Somatic mutations in USP8 are common in Nelson's tumors, indicating that they do not drive the corticotroph tumor progression that leads to NS, and may be associated with a less favorable biochemical outcome after surgery for Nelson's tumor., (© 2018 European Society of Endocrinology.)
- Published
- 2018
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7. Persistence of myopathy in Cushing's syndrome: evaluation of the German Cushing's Registry.
- Author
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Berr CM, Stieg MR, Deutschbein T, Quinkler M, Schmidmaier R, Osswald A, Reisch N, Ritzel K, Dimopoulou C, Fazel J, Hahner S, Stalla GK, Beuschlein F, and Reincke M
- Subjects
- Adult, Aged, Aged, 80 and over, Case-Control Studies, Cohort Studies, Cross-Sectional Studies, Cushing Syndrome physiopathology, Disease Progression, Female, Follow-Up Studies, Germany, Glucocorticoids therapeutic use, Hand Strength, Humans, Male, Middle Aged, Muscle, Skeletal drug effects, Muscular Diseases chemically induced, Muscular Diseases etiology, Muscular Diseases prevention & control, Prospective Studies, Psychomotor Performance drug effects, Registries, Remission Induction, Adrenalectomy adverse effects, Cushing Syndrome surgery, Glucocorticoids adverse effects, Hormone Replacement Therapy adverse effects, Muscle, Skeletal physiopathology, Muscular Diseases physiopathology
- Abstract
Background: Cushing's syndrome (CS) is characterized by an excessive secretion of glucocorticoids that results in a characteristic clinical phenotype. One feature of clinical hypercortisolism is breakdown of protein metabolism translating into clinical consequences including glucocorticoid-induced myopathy. While surgery is effective in control of cortisol excess, the effect of biochemical remission on muscular function is yet unclear., Methods: In a cross-sectional study we analyzed 47 patients with CS during the florid phase (ActiveCS). 149 additional patients were studied 2-53 years (mean: 13 years) after surgery in biochemical long-term remission (RemissionCS). Also, 93 rule-out CS patients were used as controls (CON). All subjects were assessed for grip strength using a hand grip dynamometer and underwent the chair rising test (CRT)., Results: Hand grip strength (85% vs 97% of norm, P = 0.002) and the CRT performance (9.5 s vs 7.1 s, P = 0.001) were significantly lower in ActiveCS compared to the CON group. Six months after treatment grip strength further decreased in CS ( P = 0.002) and CRT performance remained impaired. The RemissionCS group (mean follow-up 13 years) had reduced hand grip strength (92% compared to normal reference values for dominant hand, P < 0.001). The chair rising test performance was at 9.0 s and not significantly different from the ActiveCS group ( P = 0.45)., Conclusion: CS affects muscle strength in the acute phase, but functional impairment remains detectable also during long-term follow-up despite biochemical remission., (© 2017 European Society of Endocrinology.)
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- 2017
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8. Advances in understanding hypopituitarism.
- Author
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Stieg MR, Renner U, Stalla GK, and Kopczak A
- Abstract
The understanding of hypopituitarism has increased over the last three years. This review provides an overview of the most important recent findings. Most of the recent research in hypopituitarism has focused on genetics. New diagnostic techniques like next-generation sequencing have led to the description of different genetic mutations causative for congenital dysfunction of the pituitary gland while new molecular mechanisms underlying pituitary ontogenesis have also been described. Furthermore, hypopituitarism may occur because of an impairment of the distinctive vascularization of the pituitary gland, especially by disruption of the long vessel connection between the hypothalamus and the pituitary. Controversial findings have been published on post-traumatic hypopituitarism. Moreover, autoimmunity has been discussed in recent years as a possible reason for hypopituitarism. With the use of new drugs such as ipilimumab, hypopituitarism as a side effect of pharmaceuticals has come into focus. Besides new findings on the pathomechanism of hypopituitarism, there are new diagnostic tools in development, such as new growth hormone stimulants that are currently being tested in clinical trials. Moreover, cortisol measurement in scalp hair is a promising tool for monitoring cortisol levels over time., Competing Interests: Competing interests: The authors declare that they have no competing interests.No competing interests were disclosed.No competing interests were disclosed.
- Published
- 2017
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9. Investigating the role of cortisol and growth hormone in fatty liver development: fatty liver index in patients with pituitary adenomas.
- Author
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Auer MK, Stalla GK, and Stieg MR
- Subjects
- Adenoma blood, Adrenal Insufficiency complications, Adult, Aged, Cardiovascular Diseases blood, Case-Control Studies, Female, Humans, Male, Middle Aged, Non-alcoholic Fatty Liver Disease blood, Non-alcoholic Fatty Liver Disease diagnosis, Pituitary ACTH Hypersecretion blood, Pituitary Neoplasms blood, Risk Factors, Severity of Illness Index, Adenoma complications, Growth Hormone deficiency, Hydrocortisone blood, Non-alcoholic Fatty Liver Disease etiology, Pituitary ACTH Hypersecretion complications, Pituitary Neoplasms complications
- Abstract
Purpose: Non-alcoholic fatty liver disease (NAFLD) is a hallmark of the metabolic syndrome and has been shown to be an independent predictor of cardiovascular mortality. Although glucocorticoids and growth hormone are known to be implicated in its pathophysiology, it has only rarely been investigated in the context of patients with pituitary insufficiency or former cortisol excess., Methods: Case-control study in patients with biochemically controlled Cushing's disease (CD; N = 33) and non-functioning pituitary adenomas (NFPA; N = 79). NAFLD was estimated by calculating the fatty liver index (FLI) including BMI, waist circumference, GGT and triglyceride levels., Results: Although there was no difference in FLI between patients with NFPA and CD, we identified average daily hydrocortisone (HC) intake in those with adrenal insufficiency to be an independent predictor of FLI (β = 1.124; p = 0.017), even after adjusting for BMI and waist circumference. In line, those with a FLI > 60 were also taking in average significantly more HC per day than those with a score <60 (21.05 mg ± 5.9 vs. 17.9 mg ± 4.4; p = 0.01). FLI was also the best independent predictor for HbA1c and fasting glucose levels (both p = 0.001). Growth hormone deficiency and replacement therapy were not associated with FLI in either group., Conclusions: While HC dosage affects FLI as an estimate of NFLD in patients with CD and NFPA, the benefit of GH replacement still needs to be determined. In contrast to reports in CD patients with active disease, NAFLD in those with biochemical control was not different from NFPA patients., Competing Interests: Compliance with ethical standardsConflict of interestG.K.S. has been a consultant for Sandoz and Pfizer and has participated in medical education activities organized by, and has received investigator-initiated research grants from Pfizer. M.K.A. has received honoraria for public speaking from Pfizer and NovoNordisk and reimbursement for travel expenses to attend conferences from Pfizer and Lilly. M.R.S. has received reimbursement for travel expenses to attend conferences from Lilly. M.K.A. and M.R.S. have received a young investigator fellowship from Pfizer.Ethical approvalAll patients gave written informed consent to be part of the NeoExNET registry and the study was approved by the ethical review board of the Ludwig Maximilian University of Munich.
- Published
- 2016
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10. Is insulin-like growth factor-I a good marker for treatment adherence in growth hormone deficiency in adulthood?
- Author
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Auer MK, Stieg MR, Hoffmann J, and Stalla GK
- Subjects
- Adolescent, Adult, Age Factors, Aged, Aged, 80 and over, Biomarkers analysis, Cohort Studies, Female, Human Growth Hormone deficiency, Humans, Male, Middle Aged, Retrospective Studies, Sex Factors, Young Adult, Human Growth Hormone therapeutic use, Insulin-Like Growth Factor I analysis, Medication Adherence statistics & numerical data
- Abstract
Objective: There is a paucity of studies on adherence to growth hormone treatment in growth hormone deficient (GHD) adults. Therefore, this study reports on adherence to GH-replacement therapy in adults with GHD, with a special focus on the course and potential predictors of nonadherence., Design: Retrospective single-centre cohort study., Patients: From the local patient database, 179 suitable patients with GHD were identified., Measurements: The primary outcome was adherence assessed by calculating the percentage of available prescription data in comparison with recommended GH dosages over a mean follow-up period of 92·4 months. Patients were categorized into five adherence categories ranging from <20% to >80%., Results: Mean overall adherence was 74·0%, with 52·9% of patients falling into the adherence group of >80% and 8·8% of <20%. There was a significant drop in adherence (9·8%) between the first and second years of treatment (P < 0·001). Patients with childhood-onset GHD were significantly less adherent to GH treatment than patients with adult-onset GHD (62·0% vs 77·0%, P = 0·012); however, this finding was no longer significant after including age as a covariate. Frequency of IGF-1 levels lying outside the age- and sex-specific reference range was not a good indicator for adherence., Conclusion: Although overall adherence was relatively high in our study sample, there is a significant amount of patients who should be regarded as nonadherent. This applies in particular to younger patients. Treating physicians should be aware of the fact that IGF-1 levels do not seem to be a good indicator for adherence., (© 2016 John Wiley & Sons Ltd.)
- Published
- 2016
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11. Leptin: A hormone linking activation of neuroendocrine axes with neuropathology.
- Author
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Stieg MR, Sievers C, Farr O, Stalla GK, and Mantzoros CS
- Subjects
- Cognition physiology, Humans, Hydrocortisone metabolism, Stress, Psychological metabolism, Hypothalamo-Hypophyseal System metabolism, Leptin metabolism, Pituitary-Adrenal System metabolism
- Abstract
Leptin, a peptide hormone secreted by adipocytes, plays a central role in controlling appetite and weight in both rodents and humans. Basic science and clinical research suggest that this hormone not only affects the regulation of the neuroendocrine axes, but also exerts effects on the central nervous system with subsequent alterations in psychological functions. For instance, leptin suppresses cortisol secretion during stress-related activation of the adrenal axis. As psychiatric disorders like depression are associated with hypercortisolism, leptin is proposed to exert anti-depressant-like effects due to its inhibition of chronically overactive hypothalamo-pituitary-adrenal axis function. Moreover, leptin status of depressed patients could serve as a prognostic marker for therapy response. Besides its influence on neuroendocrine pathways leptin seems to have direct central effects on brain development and neuroplasticity. Low leptin levels have been shown to be associated with increased risk of developing dementia, supporting the idea of a pro-cognitive effect of leptin. These areas may have direct clinical implications and deserve to be studied further in the future., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2015
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12. RIG-I-like helicases induce immunogenic cell death of pancreatic cancer cells and sensitize tumors toward killing by CD8(+) T cells.
- Author
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Duewell P, Steger A, Lohr H, Bourhis H, Hoelz H, Kirchleitner SV, Stieg MR, Grassmann S, Kobold S, Siveke JT, Endres S, and Schnurr M
- Subjects
- Animals, Cell Line, Tumor, Cross-Priming, Cytokines metabolism, Cytotoxicity, Immunologic, Dendritic Cells immunology, Female, Immunotherapy, Inflammasomes metabolism, Interferon Type I physiology, Mice, Inbred C57BL, Mice, Knockout, Neoplasm Transplantation, Pancreatic Neoplasms immunology, Pancreatic Neoplasms therapy, T-Lymphocytes, Cytotoxic immunology, Toll-Like Receptors metabolism, Apoptosis immunology, CD8-Positive T-Lymphocytes immunology, DEAD-box RNA Helicases physiology, Pancreatic Neoplasms pathology
- Abstract
Pancreatic cancer is characterized by a microenvironment suppressing immune responses. RIG-I-like helicases (RLH) are immunoreceptors for viral RNA that induce an antiviral response program via the production of type I interferons (IFN) and apoptosis in susceptible cells. We recently identified RLH as therapeutic targets of pancreatic cancer for counteracting immunosuppressive mechanisms and apoptosis induction. Here, we investigated immunogenic consequences of RLH-induced tumor cell death. Treatment of murine pancreatic cancer cell lines with RLH ligands induced production of type I IFN and proinflammatory cytokines. In addition, tumor cells died via intrinsic apoptosis and displayed features of immunogenic cell death, such as release of HMGB1 and translocation of calreticulin to the outer cell membrane. RLH-activated tumor cells led to activation of dendritic cells (DCs), which was mediated by tumor-derived type I IFN, whereas TLR, RAGE or inflammasome signaling was dispensable. Importantly, CD8α(+) DCs effectively engulfed apoptotic tumor material and cross-presented tumor-associated antigen to naive CD8(+) T cells. In comparison, tumor cell death mediated by oxaliplatin, staurosporine or mechanical disruption failed to induce DC activation and antigen presentation. Tumor cells treated with sublethal doses of RLH ligands upregulated Fas and MHC-I expression and were effectively sensitized towards Fas-mediated apoptosis and cytotoxic T lymphocyte (CTL)-mediated lysis. Vaccination of mice with RLH-activated tumor cells induced protective antitumor immunity in vivo. In addition, MDA5-based immunotherapy led to effective tumor control of established pancreatic tumors. In summary, RLH ligands induce a highly immunogenic form of tumor cell death linking innate and adaptive immunity.
- Published
- 2014
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13. Therapeutic efficacy of bifunctional siRNA combining TGF-β1 silencing with RIG-I activation in pancreatic cancer.
- Author
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Ellermeier J, Wei J, Duewell P, Hoves S, Stieg MR, Adunka T, Noerenberg D, Anders HJ, Mayr D, Poeck H, Hartmann G, Endres S, and Schnurr M
- Subjects
- Animals, Apoptosis, CD8-Positive T-Lymphocytes immunology, Chemokine CXCL10 blood, DEAD Box Protein 58, Enzyme-Linked Immunosorbent Assay, Female, Flow Cytometry, Interferon Type I blood, Mice, Mice, Inbred C57BL, Pancreatic Neoplasms immunology, Pancreatic Neoplasms metabolism, Pancreatic Neoplasms pathology, RNA, Small Interfering therapeutic use, Real-Time Polymerase Chain Reaction, Signal Transduction, DEAD-box RNA Helicases metabolism, Gene Silencing, Pancreatic Neoplasms genetics, RNA, Small Interfering genetics, Transforming Growth Factor beta1 genetics
- Abstract
Deregulated TGF-β signaling in pancreatic cancer promotes tumor growth, invasion, metastasis, and a potent immunosuppressive network. A strategy for disrupting this tumor-promoting pathway is silencing TGF-β by siRNA. By introducing a triphosphate group at the 5' end of siRNA (ppp-siRNA), gene silencing can be combined with immune activation via the cytosolic helicase retinoic acid-inducible gene I (RIG-I), a ubiquitously expressed receptor recognizing viral RNA. We validated RIG-I as a therapeutic target by showing that activation of RIG-I in pancreatic carcinoma cells induced IRF-3 phosphorylation, production of type I IFN, the chemokine CXCL10, as well as caspase-9-mediated tumor cell apoptosis. Next, we generated a bifunctional ppp-siRNA that combines RIG-I activation with gene silencing of TGF-β1 (ppp-TGF-β) and studied its therapeutic efficacy in the orthotopic Panc02 mouse model of pancreatic cancer. Intravenous injection of ppp-TGF-β reduced systemic and tumor-associated TGF-β levels. In addition, it induced high levels of type I IFN and CXCL10 in serum and tumor tissue, systemic immune cell activation, and profound tumor cell apoptosis in vivo. Treatment of mice with established tumors with ppp-TGF-β significantly prolonged survival as compared with ppp-RNA or TGF-β siRNA alone. Furthermore, we observed the recruitment of activated CD8(+) T cells to the tumor and a reduced frequency of CD11b(+) Gr-1(+) myeloid cells. Therapeutic efficacy was dependent on CD8(+) T cells, whereas natural killer cells were dispensable. In conclusion, combing TGF-β gene silencing with RIG-I signaling confers potent antitumor efficacy against pancreatic cancer by breaking tumor-induced CD8(+) T cell suppression.
- Published
- 2013
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