Individual ventilated cages (IVC) are increasing in popularity. Although mice avoid IVC in preference testing, they show no aversion when provided additional nesting material or the cage is not ventilated. Given the high ventilation rate in IVC, we developed 3 hypotheses: that mice housed in IVC experience more cold stress than do mice housed in static cages; that IVC-induced cold stress affects the results of experiments using mice; and that, when provided shelters, mice behaviorally thermoregulate and thereby rescue the cold-stress effects of IVC. To test these hypotheses, we housed mice in IVC, IVC with shelters, and static cages maintained at 20 to 21 °C. We quantified the cold stress of each housing system on mice by assessing nonshivering thermogenesis and brown adipose vacuolation. To test housing effects in a common, murine model of human disease, we implanted mice with subcutaneous epidermoid carcinoma cells and quantified tumor growth, tumor metabolism, and adrenal weight. Mice housed in IVC had histologic signs of cold stress and significantly higher nonshivering thermogenesis, smaller subcutaneous tumors, lower tumor metabolism, and larger adrenal weights than did mice in static cages. Shelters rescued IVC-induced nonshivering thermogenesis, adrenal enlargement, and phenotype-dependent cold-mediated histologic changes in brown adipose tissue and tumor size. IVC impose chronic cold stress on mice, alter experimental results, and are a source of systemic confounders throughout rodent-dependent research. Allowing mice to exhibit behavioral thermoregulation through seeking shelter markedly rescues the experiment-altering effects of housing-imposed cold stress, improves physiologic uniformity, and increases experimental reproducibility across housing systems.
Retinal toxicity is one of the leading causes of attrition in drug development, and drug-induced retinal toxicity remains an issue in both drug discovery and postmarketed drugs. Derisking strategies to help with early identification of retinal injury utilizing a predictive retinal miRNA biomarker would greatly benefit decision-making in drug discovery programs, ultimately reducing attrition due to retinal toxicity. Our previous work demonstrated elevation of circulating retina-enriched miRNAs in a retinal toxicity model. To further validate our previous observation, 2 additional rat retinal injury models were utilized in this study: NaIO3-induced retinal injury and laser-induced choroidal neovascularization (CNV) injury model. Following induction of retina tissue injuries, circulating miR-183/96/182 cluster (miR-183 cluster), and miR-124 was investigated, as well as evaluations using an electroretinogram (ERG) and histopathology analysis. Data revealed that circulating miR-183/96/182 cluster was significantly increased (2- to 15-fold) compared with baseline/control in both laser-induced CNV and NaIO3-induced retinal injury models. Moreover, the severity of the retinal injury evaluated by ERG and histopathology correlated highly with elevation of these retina-enriched miRNAs in plasma. MiR-124 was also significantly increased in comparison with baseline/control by ∼25-fold postrepeat-doses of 30 mg/kg NaIO3 treatment. Increased level of these plasma miRNA biomarkers appeared to be dose- and time-dependent upon NaIO3 or laser treatment. The results suggest that the retina-enriched miRNAs (miR-183/96/182 cluster and miR-124) could serve as convenient and predictive biomarkers of retinal toxicity in drug development.
e15581 Background: We sought to investigate whether preoperative serum CA 19-9 and CEA levels are predictive of resectability, postoperative outcomes, and survival in resectable GC. Methods: The National Cancer Database (NCDB) was interrogated to identify resectable GC patients between 2004-2015. Gastric adenocarcinoma cases without M1 disease and who did or did not undergo definitive surgery were included. Pretreatment CA 19-9 and CEA levels were classified as high (≥98 U/mL) or low ( < 98 U/mL). Proportions of categorical variables were compared using the Chi-squared test (two-tailed). Hazard ratios (HRs) for overall survival (OS) were compared using multivariate Cox regression, adjusting for baseline demographic and clinical variables. Results: From 183,204 GC cases screened, a final 5,447 patients were available. Resection rates for patients with low (n = 1920) and high (n = 294) CA 19-9 were 69.2% and 40.8% (χ² 90.6, p < 0.00001). 69.6% were resectable with low CEA (n = 5044) and 35.1% were resectable with high CEA (n = 97, χ² 53.0, p < 0.00001). Mortality within 30 days of definitive surgery was 7.5% and 0% in those with high (n = 120) and low CA 19-9 (n = 1286, χ² 85.6, p < 0.00001). There was no significant difference between 30-day mortality across high and low CEA and between 30-day readmission rates across high and low CA 19-9 and CEA levels. Age, median income, high school graduation rate, Charlson comorbidity index, and AJCC clinical N stage all significantly correlated with OS in this cohort. Compared to low preoperative CA 19-9, high CA 19-9 was significantly associated with worse OS (HR 1.24, 95% confidence interval (CI) 1.13-1.37, p < 0.0001). Similarly, a high CEA correlated with worse OS compared to low CEA (HR 1.44, 95% CI 1.32-1.57, p < 0.0001). Conclusions: High preoperative CA 19-9 and CEA are associated wither lower resection rates and worse OS in resectable GC. CA 19-9 but not CEA level predicts for 30-day mortality. Prospective validation is warranted.
Abstract OBJECTIVE To evaluate the safety and feasibility of combining resection with immediate initiation of radiation and subsequent Stupp protocol in newly-diagnosed glioblastoma (GBM). BACKGROUND Rapid early local progression (REP) after resection, prior to the initiation of EBRT+/-chemotherapy, occurs in 25-50%. This high-rate of REP supports initiation of an effective postoperative treatment as early as safely possible. Bio-resorbable collagen tiles with imbedded cesium-131 radiation sources (Gammatiles™) are FDA cleared for this use. Intraoperatively, tiles are placed within the resection bed, thus achieving an immediate initiation of surgically targeted radiation therapy (STaRT). DESIGN/ METHODS GESTALT is a single-arm 61 patient multi-center trial. Consented adults with suspected or confirmed GBM undergo a maximum safe resection with Gammatile™ (STaRT). Patients with molecular GBM (WHO 2021 criteria) start concurrent EBRT/Temozolomide beginning 25±4 days post-surgery. Subsequent EBRT (20 fractions, 4 weeks) to low and high-risk PTV takes Gammatile™ dose into account to a combined biologically equivalent dose of 46 and 60 Gy delivered in 2Gy/fraction, respectively. Adjuvant TMZ (6 cycles) begins 28±7 days after EBRT/Temozolomide. TTF is allowed. IDH-mutated gliomas are followed for safety. Outcomes include feasibility of incorporating Gammatile™ without delay of Stupp protocol, consent/attrition rates, safety, performance status trajectory (ECOG, KPS), immune competence (absolute lymphocyte counts), local control, PFS, and OS. RESULTS The trial opened in Fall 2022 at 4 sites. 12 additional sites are onboarding (NCT05342883). 16 patients are on trial as of abstract submission. Currently, this trial appears feasible and without any unexpected intolerances/toxicities. CONCLUSIONS This is the first trial in newly diagnosed GBM patients to combine resection, Gammatile™, and the Stupp protocol, in an attempt to reduce REP, as well as possibly, improve other outcomes. RESULTS will inform the routine and investigational use of Gammatile™, and if suggestive, will form the basis for a subsequent randomized trial.
Abstract Introduction Evidence‐based recommendations on duration of multiagent systemic therapy for LAPC are lacking. Herein, we assess the impact of duration of combination systemic therapy on survival of patients with LAPC. Methods The National Cancer Database was interrogated to identify patients with untreated LAPC diagnosed from 2004 to 2014. Patients treated with ≥ 1 month of multiagent chemotherapy (MAC) and ≥ 6 months of follow‐up were included. Kaplan‐Meier survival curves were generated to examine OS of each MAC duration group. Univariable and multivariable Cox proportional hazards regression was used to examine the association between OS with demographic and clinical variables. Statistical computations were performed using SAS Software Version 9.4. Results Of the 3410 patients, 1114 met inclusion criteria. Median age was 64 years. Median treatment duration was 3.2 months (range 1‐19.8). Median follow‐up was 23.5 months (range 3‐120). Median OS of all patients was 9.4 months (95% CI: 8.7‐10.1). Median OS of patients receiving ≥ 1‐4 months, >4‐6 months and > 6 months of MAC was 8.4 months (95% CI: 7.7‐9), 10.2 months (95% CI: 9‐11.8), and 12.8 months (95% CI 11.6‐16). Twelve‐month survival was 37% for patients receiving ≥ 1‐4 months, 43% for > 4‐6 months, and 56% for > 6 months. Female sex ( P = .02), higher median household income ( P = .03), and longer duration of MAC ( P < .001) were independently associated with improved OS following multivariable analysis. Conclusion This analysis in LAPC patients suggests that combination systemic therapy regimens of 6 months or more may optimize survival outcomes. Further investigation on the duration of systemic therapy question in LAPC is needed.
IL13Rα2 is a cell surface tumor antigen that is overexpressed in multiple tumor types. Here, we studied biodistribution and targeting potential of an anti-IL13Rα2 antibody (Ab) and anti-tumor activity of anti-IL13Rα2-antibody-drug conjugate (ADC). The anti-IL13Rα2 Ab was labeled with fluorophore AF680 or radioisotope 89Zr for in vivo tracking using fluorescence molecular tomography (FMT) or positron emission tomography (PET) imaging, respectively. Both imaging modalities showed that the tumor was the major uptake site for anti-IL13Rα2-Ab, with peak uptake of 5–8% ID and 10% ID/g as quantified from FMT and PET, respectively. Pharmacological in vivo competition with excess of unlabeled anti-IL13Rα2-Ab significantly reduced the tumor uptake, indicative of antigen-specific tumor accumulation. Further, FMT imaging demonstrated similar biodistribution and pharmacokinetic profiles of an auristatin-conjugated anti-IL13Rα2-ADC as compared to the parental Ab. Finally, the anti-IL13Rα2-ADC exhibited a dose-dependent anti-tumor effect on A375 xenografts, with 90% complete responders at a dose of 3 mg/kg. Taken together, both FMT and PET showed a favorable biodistribution profile for anti-IL13Rα2-Ab/ADC, along with antigen-specific tumor targeting and excellent therapeutic efficacy in the A375 xenograft model. This work shows the great potential of this anti-IL13Rα2-ADC as a targeted anti-cancer agent.
Unlike the majority of cancers, survival for lung cancer has not shown much improvement since the early 1970s and survival rates remain low. Genetically engineered mice tumor models are of high translational relevance as we can generate tissue specific mutations which are observed in lung cancer patients. Since these tumors cannot be detected and quantified by traditional methods, we use micro-computed tomography imaging for longitudinal evaluation and to measure response to therapy. Conventionally, we analyze microCT images of lung cancer via a manual segmentation. Manual segmentation is time-consuming and sensitive to intra- and inter-analyst variation. To overcome the limitations of manual segmentation, we set out to develop a fully-automated alternative, the Mouse Lung Automated Segmentation Tool (MLAST). MLAST locates the thoracic region of interest, thresholds and categorizes the lung field into three tissue categories: soft tissue, intermediate, and lung. An increase in the tumor burden was measured by a decrease in lung volume with a simultaneous increase in soft and intermediate tissue quantities. MLAST segmentation was validated against three methods: manual scoring, manual segmentation, and histology. MLAST was applied in an efficacy trial using a Kras/Lkb1 non-small cell lung cancer model and demonstrated adequate precision and sensitivity in quantifying tumor growth inhibition after drug treatment. Implementation of MLAST has considerably accelerated the microCT data analysis, allowing for larger study sizes and mid-study readouts. This study illustrates how automated image analysis tools for large datasets can be used in preclinical imaging to deliver high throughput and quantitative results.
