P53-Mediated Radiosensitization of 177Lu-DOTATATE in Neuroblastoma Tumor Spheroids.
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SUBMITTER: Lundsten S
PROVIDER: S-EPMC8615514 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:177Lu‑DOTATATE was recently approved for the treatment of somatostatin receptor (SSTR)‑positive neuroendocrine tumors (NETs). However, despite impressive response rates, complete responses are rare. Heat shock protein 90 (HSP90) inhibitors have been suggested as suitable therapeutic agents for NETs, as well as a potential radiosensitizers. Consequently, the aim of this study was to investigate whether the HSP90‑inhibitor onalespib could reduce NET cell growth and act as a radiosensitizer when used in combination with 177Lu‑DOTATATE. The NET cell lines BON, NCI‑H727 and NCI‑H460, were first characterized with regards to 177Lu‑DOTATATE uptake and sensitivity to onalespib treatment in monolayer cell assays. The growth inhibitory effects of the monotherapies and combination treatments were then examined in three‑dimensional multicellular tumor spheroids. Lastly, the molecular effects of the treatments were assessed. 177Lu‑DOTATATE uptake was observed in the BON and NCI‑H727 cells, while the NCI‑H460 cells exhibited no detectable uptake. Accordingly, 177Lu‑DOTATATE reduced the growth of BON and NCI‑H727 spheroids, while no effect was observed in the NCI‑H460 spheroids. Onalespib reduced cell viability and spheroid growth in all three cell lines. Furthermore, the combination of onalespib and 177Lu‑DOTATATE exerted synergistic therapeutic effects on the BON and NCI‑H727 spheroids. Western blot analysis of BON spheroids revealed the downregulation of epidermal growth factor receptor (EGFR) and the upregulation of γ H2A histone family member X (γH2AX) following combined treatment with onalespib and 177Lu‑DOTATATE. Moreover, flow cytometric analyses revealed a two‑fold increase in caspase 3/7 activity in the combination group. In conclusion, the findings of this study demonstrate that onalespib exerts antitumorigenic effects on NET cells and may thus be a feasible treatment option for NETs. Furthermore, onalespib was able to synergistically potentiate 177Lu‑DOTATATE treatment in a SSTR‑specific manner. The radiosensitizing mechanisms of onalespib involved the downregulation of EGFR expression and the induction of apoptosis. Consequently, the combination of onalespib and 177Lu‑DOTATATE may prove to be a promising strategy with which to improve therapeutic responses in patients with NETs. Further studies investigating this strategy in vivo regarding the therapeutic effects and potential toxicities are warranted to expand these promising findings.
| S-EPMC6831206 | biostudies-literature
Project description:PURPOSE:177Lu-DOTATATE targeting the somatostatin receptor (SSTR) is utilized for treatment of neuroendocrine tumors (NETs). Onalespib, a heat shock protein 90 (HSP90) inhibitor, has demonstrated radiosensitizing properties and may thus enhance the effect of 177Lu-DOTATATE. Consequently, the aim of this study was to assess the potential of Onalespib in combination with 177Lu-DOTATATE in vivo and to examine the toxicity profiles of the treatments. METHODS:177Lu-DOTATATE selectivity and distribution in NET xenografts were studied using biodistribution and autoradiography. Therapeutic effects of Onalespib in combination with 177Lu-DOTATATE were studied in NET xenografts. Histological analyses were used to assess molecular effects from treatment and to establish toxicity profiles. RESULTS:Biodistribution and autoradiography confirmed the SSTR-selective tumor uptake of 177Lu-DOTATATE, which was unaffected by Onalespib treatment. Immunohistochemistry verified molecular responses to Onalespib therapy in the tumors. While Onalespib and 177Lu-DOTATATE monotherapies resulted in a 10% and 33% delay in tumor doubling time compared with control, the combination treatment resulted in a 73% delayed tumor doubling time. Moreover, combination treatment increased complete remissions threefold from 177Lu-DOTATATE monotherapy, resulting in 29% complete remissions. In addition, histological analyses demonstrated radiation-induced glomerular injury in the 177Lu-DOTATATE monotherapy group. The damage was decreased tenfold in the combination group, potentially due to Onalespib-induced HSP70 upregulation in the kidneys. CONCLUSION:Treatment with Onalespib potentiated 177Lu-DOTATATE therapy of NET xenografts with a favorable toxicity profile. Utilizing Onalespib's radiosensitizing properties with 177Lu-DOTATATE may lead to better therapeutic results in the future and may reduce unwanted side effects in dose-limiting organs.
| S-EPMC7075859 | biostudies-literature
Project description:BACKGROUND:The role of concomitant peptide receptor radionuclide therapy (PRRT) and capecitabine therapy has shown benefit in gastroenteropancreatic neuroendocrine tumors. However, data reporting its role in paraganglioma (PGL) patients is lacking. The aim of this study was to evaluate the role of combined capecitabine and 177Lu-DOTATATE in malignant PGL patients. METHODS:In this retrospective, single-institutional, single-arm, observational study, data of consecutive advanced stage PGL patients treated with concomitant 177Lu-DOTATATE-capecitabine therapy, between July 2009 and March 2017, were collected and analyzed. RESULTS:Twenty-five PGL patients received an average dose of 22.86?±?9.54 (14.43-50) GBq 177Lu-DOTATATE and 1250?mg/m2 capecitabine from days 0 to 14, commencing on the morning of PRRT. The median overall survival (OS) was not attained in this patient cohort; however, the median PFS was 32?months. Morphological response according to RECIST 1.1 criteria was achieved in 28% (7/25) patients. Biochemical response with >?50% reduction in chromogranin A levels was observed in 28% of the patients. CONCLUSIONS:Our data confirm that 177Lu-DOTATATE-capecitabine therapy is effective in achieving an objective response in 28% and symptomatic response in 43% patients. In comparison to published PRRT monotherapy outcomes in PGL, we did not observe any great advantage of concomitant therapy; however, it could be due to under-powered study. We recommend a large randomized trial to prove or disprove the utility of capecitabine as a radiosensitizer for PRRT in PGL patients.
| S-EPMC6365580 | biostudies-literature
Project description:Introduction: 177Lutetium-[DOTA°,Tyr3]octreotate (177Lu-DOTATATE) is a type of peptide receptor radionuclide therapy that garnered FDA approval in January 2018 for the treatment of somatostatin receptor-positive gastroenteropancreatic (GEP) neuroendocrine tumor (NET) patients. The therapy approval was based on findings from the randomized international phase III NETTER-1 trial as well as outcome data from a large European registry. The mechanism of the drug stems directly from its structure: a somatostatin analog (octreotate) selectively binding to somatostatin receptor expressing cells and being internalized, along with a chelated beta-emitting isotope 177Lu.Areas Covered: Herein we describe the pharmacology, clinical efficacy and adverse event data from prospective and retrospective studies with 177Lu-DOTATATE. We discuss the role of 177Lu-DOTATATE within the current treatment landscape for GEP NET patients.Expert Opinion: 177Lu-DOTATATE represents a unique addition to the treatment armamentarium for GEP NETs because of its potential to elicit tumor cytoreduction, which is rare among other existing treatment options, and prolonged disease control. Where 177Lu-DOTATATE fits into the treatment sequence for GEP NET patients remains an area of active investigation.
| S-EPMC7227421 | biostudies-literature
Project description:BACKGROUND:Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 (177Lu)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors. METHODS:We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either 177Lu-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) (177Lu-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here. RESULTS:At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the 177Lu-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the 177Lu-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the 177Lu-Dotatate group and 26 in the control group (P=0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the 177Lu-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame. CONCLUSIONS:Treatment with 177Lu-Dotatate resulted in markedly longer progression-free survival and a significantly higher response rate than high-dose octreotide LAR among patients with advanced midgut neuroendocrine tumors. Preliminary evidence of an overall survival benefit was seen in an interim analysis; confirmation will be required in the planned final analysis. Clinically significant myelosuppression occurred in less than 10% of patients in the 177Lu-Dotatate group. (Funded by Advanced Accelerator Applications; NETTER-1 ClinicalTrials.gov number, NCT01578239 ; EudraCT number 2011-005049-11 .).
| S-EPMC5895095 | biostudies-literature
Project description:Targeted radiotherapy of metastatic neuroblastoma using the somatostatin receptor (SSTR)-targeted octreotide analogue DOTATATE radiolabelled with lutetium-177 (177Lu-DOTATATE) is a promising strategy. This study evaluates whether its effectiveness may be enhanced by combination with radiosensitising drugs. The growth rate of multicellular tumour spheroids, derived from the neuroblastoma cell lines SK-N-BE(2c), CHLA-15 and CHLA-20, was evaluated following treatment with 177Lu-DOTATATE, nutlin-3 and topotecan alone or in combination. Immunoblotting, immunostaining and flow cytometric analyses were used to determine activation of p53 signalling and cell death. Exposure to 177Lu-DOTATATE resulted in a significant growth delay in CHLA-15 and CHLA-20 spheroids, but not in SK-N-BE(2c) spheroids. Nutlin-3 enhanced the spheroid growth delay induced by topotecan in CHLA-15 and CHLA-20 spheroids, but not in SK-N-BE(2c) spheroids. Importantly, the combination of nutlin-3 with topotecan enhanced the spheroid growth delay induced by X-irradiation or by exposure to 177Lu-DOTATATE. The efficacy of the combination treatments was p53-dependent. These results indicate that targeted radiotherapy of high risk neuroblastoma with 177Lu-DOTATATE may be improved by combination with the radiosensitising drugs nutlin-3 and topotecan.
| S-EPMC6044389 | biostudies-literature
Project description:PURPOSE:To present data from an interim analysis of a Phase II trial designed to determine the feasibility, safety, and efficacy of individualising treatment based on renal dosimetry, by giving as many cycles as possible within a maximum renal biologically effective dose (BED). METHOD:Treatment was given with repeated cycles of 7.4 GBq 177Lu-DOTATATE at 8-12-week intervals. Detailed dosimetry was performed in all patients after each cycle using a hybrid method (SPECT?+?planar imaging). All patients received treatment up to a renal BED of 27?±?2 Gy (?/??=?2.6 Gy) (Step 1). Selected patients were offered further treatment up to a renal BED of 40?±?2 Gy (Step 2). Renal function was followed by estimation and measurement of the glomerular filtration rate (GFR). RESULTS:Fifty-one patients were included in the present analysis. Among the patients who received treatment as planned, the median number of cycles in Step 1 was 5 (range 3-7), and for those who completed Step 2 it was 7 (range 5-8); 73% were able to receive >4 cycles. Although GFR decreased in most patients after the completion of treatment, no grade 3-4 toxicity was observed. Patients with a reduced baseline GFR seemed to have an increased risk of GFR decline. Five patients received treatment in Step 2, none of whom exhibited a significant reduction in renal function. CONCLUSIONS:Individualising PRRT using renal dosimetry seems feasible and safe and leads to an increased number of cycles in the majority of patients. The trial will continue as planned.
| S-EPMC5506097 | biostudies-literature
Project description:IntroductionThe pituitary gland has a high expression of somatostatin receptors and is therefore a potential organ at risk for radiation-induced toxicity after 177Lu-DOTATATE treatment.ObjectiveTo study changes in pituitary function in patients with neuroendocrine tumors (NETs) treated with dosimetry-based 177Lu-DOTATATE to detect possible late toxicity.Methods68 patients from a phase II clinical trial of dosimetry-based, individualized 177Lu-DOTATATE therapy were included in this analysis. Patients had received a median of 5 (range 3-9) treatment cycles of 7.4 GBq/cycle. Median follow-up was 30 months (range 11-89). The GH/IGF-1 axis, gonadotropins, and adrenal and thyroid axes were analyzed at baseline and on a yearly basis thereafter. Percent changes in hormonal levels over time were analyzed statistically using a linear mixed model and described graphically using box plots. The absorbed radiation dose to the pituitary was estimated based on post-therapeutic imaging, and the results analyzed versus percent change in IGF-1 levels over time.ResultsA statistically significant decrease in IGF-1 levels was found (p < 0.005), which correlated with the number of treatment cycles (p = 0.008) and the absorbed radiation dose (p = 0.03). A similar decrease, although non-significant, was seen in gonadotropins in postmenopausal women, while in men there was an increase during the first years after therapy, after which the levels returned to baseline. No change was observed in the adrenal or thyroid axes.ConclusionsNo signs of severe endocrine disorders were detected, although a significant decrease in the GH/IGF-1 axis was found, where dosimetric analyses indicated radiation-induced damage to the pituitary gland as a probable cause.
| S-EPMC8117394 | biostudies-literature
Project description:Solid tumors, such as neuroblastoma (NB), are associated with a heterogeneous cell environment. Multicellular tumor spheroid (MCTS) cultures have been shown to better mimic growth characteristics of in vivo solid tumors. Because tumor spheroid growth patterns may be quite different from standard two-dimensional culture systems, we sought to compare the protein expression profiles of two- and three-dimensional in vitro NB cultures, i.e., monolayers and MCTS.Human NB cells were grown as both monolayers and spheres. Nuclear and cytosolic proteins were analyzed for differentially secreted proteins by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and selected polypeptides were identified by mass spectrometry (LC-MS/MS).Several metabolic (transketolase, triosephosphate isomerase, pyruvate kinase M1/M2, alpha enolase, and phosphoglycerate mutase-1), cell stress response (heat shock proteins (HSP) 90, 70, and 60; antioxidant, thioredoxin), cell structure (septin 2, adenyl cyclase-associated protein-1), tubulin beta-2 chain, actin, translationally controlled tumor protein and cofilin), signal transduction (peptidyl prolyl cis/trans isomerase A), biosynthetic (phosphoserine aminotransferase) and transport (cellular retinoic acid binding protein 1) polypeptides were overexpressed in spheroids. Several protein groups were differentially expressed between NB monolayers and spheroids.The altered proteins among NB spheroids may represent an important link between monolayer cell cultures and in vivo experiments and thus a more ideal in vitro culture system for determining the precise three-dimensional microenvironment of NB.
| S-EPMC2804865 | biostudies-literature
Project description:Purpose: To develop a care process model for the delivery of peptide receptor radionuclide therapy (PRRT) with lutetium-177 (177Lu)-Dotatate for the treatment of somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Methods: A multidisciplinary, structured PRRT process model was established. Over the last 9 months, meetings were held bi-weekly to discuss the logistics of clinical trials. Meetings are still held regularly at the Mayo Clinic Florida to discuss plans regarding commercially available PRRT treatments. The process model has evolved as we have treated patients on both clinical trials and commercial treatments. Results: An effective process model was formulated. We had 5 patients on our Expanded Access Program (EAP) clinical trial. Our ability to be a part of the EAP allowed us to understand the mechanics of how to treat these patients, and what was involved before it became commercially available. Since commercial availability of the 177Lu-Dotatate, more than 50 treatments (>20 patients) have already been completed, with several new patients getting started on treatment every week. Our nuclear medicine department receives continual requests to schedule new patients for PRRT. This can be attributed to our streamlined approach in delivering PRRT to our patients. Conclusion: A thorough procedural approach was formulated to provide patients with PRRT. Experiences and challenges led to refinement, which has allowed the process to advance. This development could lead to better patient outcomes, treatment efficiency, and a reference standard for other institutions trying to develop this at their location.
| S-EPMC6333662 | biostudies-literature