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Survival in osteosarcoma (OS) has not improved in over a decade, thus the need for new therapeutic strategies. Autophagy, a catabolic process used by cells to survive under stress, has been implicated in resistance to chemotherapy. We previously demonstrated aerosol gemcitabine (GCB) efficacy against OS lung metastasis and showed GCB to induce autophagy through the Akt/mTOR signaling pathway. Whether autophagy contributes to tumor response or resistance to GCB has been the focus of our studies. What determines whether chemotherapy-induced autophagy will lead to survival or death is unknown. We found phosphorylated heat shock protein 27 (pHSP27) to potentially define the outcome of chemotherapy-induced autophagy in OS. Small heat shock proteins, specifically HSP27, are upregulated in many cancers, including OS, and associated with treatment resistance. The purpose of this study is to investigate if induction of pHSP27 predicts the role of chemotherapy-induced autophagy in OS lung metastasis. We hypothesize that when pHSP27 is induced, blocking autophagy will lead to increased sensitivity to GCB. Furthermore, inhibition of pHSP27 may revert the effect of GCB-induced autophagy in OS cells by decreasing sensitivity to GCB. We showed in the LM7 and CCH-OS-D human metastatic OS cells in vitro, that GCB induces autophagy as determined by the conversion of microtubule-associated light chain 3 one to two (LC3I/LC3II), increase in Beclin 1, and decrease in p62 protein expression. Sensitivity of LM7 cells to GCB was enhanced after autophagy inhibition by hydroxychloroquine (HCQ), a pharmacologic inhibitor and shRNA targeting Beclin 1, suggesting autophagy as a prosurvival mechanism whereas in CCH-OS-D cells inhibition of autophagy decreased cell sensitivity to GCB, concluding here that induction of autophagy leads to cell death. We demonstrated that pHSP27 is significantly higher in GCB-treated LM7 cells as compared to CCH-OS-D cells. We also showed that inhibition of HSP27 by shRNA targeting HSP27 has no effect on GCB-induced autophagy in LM7 cells. Treatment of shHSP27LM7 with GCB resulted in an increase in LC3I/LC3II conversion and a decrease in p62. We further revealed this in vivo by conducting a pilot study in which shHSP27LM7 cells were injected i.v. into nude mice. 6 weeks later, lung metastases were confirmed. Animals were divided into two groups: untreated and aerosol GCB treated (1mg/mL three times a week). Mice were sacrificed after 2 weeks of therapy. Transmitted electron microscopy demonstrated an increase in the number of autophagosomes in lung metastasis from mice treated with GCB, confirming induction of autophagy in the absence of HSP27. Lastly, in order to demonstrate that inhibition of HSP27 will change GCB-induced autophagy response in LM7 cells, we treated shHSP27LM7 cells with the combination GCB+HCQ and showed increased viability compared to the LM7 GipZ control cells, confirming preliminarily our hypothesis that induction of pHSP27 will determine chemotherapy-induced autophagy response in OS. Citation Format: Grace Nehme, Kumar Felix, Andrew Wahba, Diana M. Fandino, Nancy Gordon. Autophagy and HSP27: A potential link to define autophagy fate in osteosarcoma [abstract]. In: Proceedings of the AACR Special Conference on Targeting PI3K/mTOR Signaling; 2018 Nov 30-Dec 8; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(10_Suppl):Abstract nr A03.

Introduction Faculty evaluations are important tools for improving faculty-to-resident instruction, but residents in our pediatric and internal medicine/pediatric residency programs would seldom evaluate individual pediatric faculty hospitalists. Our objectives were to: (1) increase the percentage of completed evaluations of individual pediatric hospitalists to greater than 85%, (2) improve the quality of pediatric hospitalist feedback as measured by resident and faculty satisfaction surveys, and (3) to reduce the resident concern of lack of anonymity of evaluations. Methods Members of the resident inpatient team (pediatric and internal medicine/pediatric residents) completed group-based evaluations of individual pediatric hospitalists. A survey to evaluate this change in process was distributed to the pediatric hospitalists (n = 6) and another survey was distributed to residents, both based on a 5-point Likert-type scale. Surveys were completed before and four months after implementation of the changes. Pre- and post-survey data of resident and hospitalist responses were compared using the Mann-Whitney test and probability proportion test. Results The percent of completed evaluations increased from 0% to 86% in one month and to 100% in two months. Thereafter, the percent of completed evaluations remained at 100% through the end of the data collection period at seven months. Hospitalists reported (n = 6, 100% participation) their satisfaction regarding the feedback they received from residents significantly increased for all survey questions. Resident satisfaction (n = 24, 89% participation in postintervention surveys) increased significantly with regards to the evaluation process. Conclusions For hospitalists, group-based resident evaluations of individual hospitalists led to an increased percentage of completed evaluations, improved the quality and quantity of feedback to hospitalists, and increased satisfaction with evaluations. For residents, these changes led to increased satisfaction with the evaluation process.

<b><i>Introduction:</i></b> We report 2 cases of medulloblastoma maturing into gangliocytoma after receiving multimodal therapy. Here we present 2 cases of diagnosed medulloblastoma which on re-resection were noted to be gangliocytoma without heterogeneity, which is an extremely rare occurrence. <b><i>Case Presentation:</i></b> The first patient, an 11-year-old boy diagnosed with high-risk (non-WNT, non-SHH) medulloblastoma, was treated with near-total surgical resection followed by craniospinal radiation therapy with weekly vincristine. He then received maintenance chemotherapy with vincristine, cyclophosphamide, and cisplatin. On surveillance MR imaging studies residual tumor in the lateral aspect of the tumor bed was noted to be slowly growing, eliciting gross-total resection of the residual tumor. Histopathology showed benign gangliocytoma without residual medulloblastoma. The second patient, a 3-year-old girl, was diagnosed with medulloblastoma, desmoplastic nodular variant. She was initially treated with gross total resection and chemotherapy with etoposide, carboplatin, and high-dose methotrexate. At 4 months off therapy, she was noted to have local recurrence along the resection cavity. Second-line therapy was started with irinotecan and temozolomide, but MRI assessment during treatment showed further disease progression. She then received craniospinal radiation. Eleven months off therapy, further radiographic progression was noted, and the patient underwent second-look surgery, with pathology showing gangliocytoma and treatment-related gliosis. <b><i>Discussion/Conclusion:</i></b> The maturation of medulloblastoma into a ganglion cell-rich lesion is very rare, with few well-characterized previous reports. Given the rare nature of this entity, it would be of great value to understand the process of posttreatment maturation and the genetic and treatment factors which contribute to this phenomenon.

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