Dumbravă, Mihai

AbstractPatient‐derived cancer organoids (PDOs) hold considerable promise for personalizing therapy selection and improving patient outcomes. However, it is challenging to generate PDOs in sufficient numbers to test therapies in standard culture platforms. This challenge is particularly acute for pancreatic ductal adenocarcinoma (PDAC) where most patients are diagnosed at an advanced stage with non‐resectable tumors and where patient tissue is in the form of needle biopsies. Here the development and characterization of microfluidic devices for testing therapies using a limited amount of tissue or PDOs available from PDAC biopsies is described. It is demonstrated that microfluidic PDOs are phenotypically and genotypically similar to the gold‐standard Matrigel organoids with the advantages of 1) spheroid uniformity, 2) minimal cell number requirement, and 3) not relying on Matrigel. The utility of microfluidic PDOs is proven by testing PDO responses to several chemotherapies, including an inhibitor of glycogen synthase kinase (GSKI). In addition, microfluidic organoid cultures are used to test effectiveness of immunotherapy comprised of NK cells in combination with a novel biologic. In summary, our microfluidic device offers considerable benefits for personalizing oncology based on cancer biopsies and may, in the future, be developed into a companion diagnostic for chemotherapy or immunotherapy treatments.

Abstract In the past decade, vascularized composite allotransplantation (VCA) has become clinical reality for reconstruction after face and hand trauma. It offers patients the unique opportunity to regain form and function in a way that had only been achieved with traditional reconstruction or with the use of prostheses. On the other hand, prostheses for facial and hand reconstruction have continued to evolve over the years and, in many cases, represent the primary option for patients after hand and face trauma. We compared the cost, associated complications, and long-term outcomes of VCA with prostheses for reconstruction of the face and hand/upper extremity. Ultimately, VCA and prostheses represent 2 different reconstructive options with distinct benefit profiles and associated limitations and should ideally not be perceived as competing choices. Our work adds a valuable component to the general framework guiding the decision to offer VCA or prostheses for reconstruction after face and upper extremity trauma.

The snATAC + snRNA platform allows epigenomic profiling of open chromatin and gene expression with single-cell resolution. The most critical assay step is to isolate high-quality nuclei to proceed with droplet-base single nuclei isolation and barcoding. With the increasing popularity of multiomic profiling in various fields, there is a need for optimized and reliable nuclei isolation methods, mainly for human tissue samples. Herein we compared different nuclei isolation methods for cell suspensions, such as peripheral blood mononuclear cells (PBMC, n = 18) and a solid tumor type, ovarian cancer (OC, n = 18), derived from debulking surgery. Nuclei morphology and sequencing output parameters were used to evaluate the quality of preparation. Our results show that NP-40 detergent-based nuclei isolation yields better sequencing results than collagenase tissue dissociation for OC, significantly impacting cell type identification and analysis. Given the utility of applying such techniques to frozen samples, we also tested frozen preparation and digestion (n = 6). A paired comparison between frozen and fresh samples validated the quality of both specimens. Finally, we demonstrate the reproducibility of scRNA and snATAC + snRNA platform, by comparing the gene expression profiling of PBMC. Our results highlight how the choice of nuclei isolation methods is critical for obtaining quality data in multiomic assays. It also shows that the measurement of expression between scRNA and snRNA is comparable and effective for cell type identification.

e17535 Background: High-grade serous ovarian carcinoma (HGSOC) is the most frequent and deadliest type of ovarian cancer (OC). With the recent advances in transcriptomic and epigenomic profiling of cancer at single cell resolution, it has become clear that intra-tumor heterogeneity driven by genetic and epigenetic factors may be the basis of drug resistance. Current treatments are not homogeneously effective against all the cancer cell subpopulations, thus enabling resistance. With single cell sequencing technology, characterization of cell signatures and regulatory mechanisms may translate to prognostic markers and novel drug targets. Methods: The transcriptomic and epigenomic landscape of HGSOC was mapped for five tumor samples from debulking surgeries and one tissue patient-derived xenograft (PDX) using the 10X genomics sequencing platform. This strategy permits the combination of single cell ATAC-seq and single cell RNA-seq within the same nucleus (Multiome). Isolation of nuclei, library preparation and sequencing were performed following 10X genomics protocols. Sample quality and library quality were assessed by nuclear morphology and fragment size analysis, respectively. Sequenced reads were mapped to the human genome and downstream analysis including copy number variant prediction, pathway enrichment, motif enrichment and gene regulatory network analysis were performed. The sampled patients continue to be followed for clinical outcomes, such as response to therapy. Clinical data including patient age, grade, and stage of cancer, debulking status, CA-125 levels, and neoadjuvant status, were used in conjunction with the genomics data to characterize patient specific molecular regulatory signatures. Results: Cells from the six samples (total N= 26,421) were projected via UMAP. Immune and stromal cells were shown to cluster by cell-type while cancer cells clustered by patient. Cancer cells were identified as cycling cells, ciliated cells, cells with enrichment of the JAK-STAT signaling pathway, and cells exhibiting cancer stemness signatures. Transcription factor motifs and binding-site enrichment in open chromatin regions reveal transcription regulation-based subpopulations. Using the combined gene expression and open chromatin information from these cells, there is potential to uncover the genetic regulatory network(s) that drives treatment resistance. Conclusions: With single cell technology, specific clusters of cancer and tumor microenvironment cells can be classified. Beyond characterizing patient specific signatures, multiome enables the discovery of genomic, transcriptomic and epigenomic signatures that provide insight in tumor progression and treatment resistance.

Post-transplant lymphoproliferative disorder (PTLD) is a complication of immunosuppressive therapy following solid organ or hematopoietic cell transplantation. Initial treatment typically includes a reduction of immunosuppression with or without rituximab. However, the optimal therapy for PTLD with plasmacytic differentiation is unclear. We present 3 cases of pediatric patients with plasmacytic PTLD. Two patients received a standard rituximab-based approach and relapsed, prompting additional chemotherapy. The third patient was treated with a novel regimen of bortezomib, dexamethasone, and daratumumab. This regimen was safe, well-tolerated, and resulted in a 2-year remission. Larger studies are needed to further explore this regimen.

AbstractBackgroundWith an increasing demand of aesthetic soft‐tissue filler treatments, the occurrence of adverse events rises likewise. An optimized injection algorithm adapted to product characteristics (eg, rheology) of the soft‐tissue filler is crucial in order to ensure satisfying clinical outcomes and high patient safety.ObjectiveTo identify a subjective feedback mechanism for the avoidance of adverse events after soft‐tissue filler injection procedures.MethodsA retrospective data analysis of n = 387 aesthetic treatments performed on n = 291 patients (4 males, 287 females) with different soft‐tissue fillers with regard to loss of volume (filling effect), injected layer, injectability (“ease of injection”), injected volume, and injection technique was conducted.ResultsThe subjectively perceived injectability during the injection process was statistically significantly related to G‐Prime value with rs = 0.101 with p = 0.048, indicating an increased difficulty while injecting products with higher G‐Prime. The occurrence of adverse events was also statistically significantly related to the injectability: injections with increased subjectively perceived difficulty showed increasing odds of developing adverse events by OR 0.157 with p = 0.002.ConclusionInjections that were subjectively more difficult to perform are more likely to develop adverse events. Respecting the layered arrangement of the face, the recommended and approved depth and facial region for each specific treatment enable practitioners to achieve satisfying outcomes while keeping the rate of adverse events low.

AbstractBackgroundUnderstanding the mobility of the midface and the separate contributions of the superficial and deep fat compartments is essential for natural esthetic outcomes following soft tissue filler or fat grafting procedures. A study was designed that used ultrasound imaging to demonstrate in vivo visualization and quantification of distances and movements in the midface.MethodsA total of 48 midfaces of 24 healthy Caucasian volunteers, all naïve of esthetic procedures, (22 females; 46.85 (9.8) years; 22.83 (3.1) kg/m2) were scanned using 18 MHz ultrasound imaging. Distances between bony landmarks (inferior orbital rim, infraorbital foramen) were used as markers to measure the cranial movement of the superficial (superficial nasolabial and superficial medial cheek fat compartment) and the deep (deep pyriform space, deep medial check fat compartment, deep lateral cheek fat compartment) midfacial fat compartments between resting and smiling facial position.ResultsThe superficial midfacial fat compartment moved, on average, 3.7 mm (p < 0.001) cranially, whereas the deep midfacial fat compartments moved, on average, 0.1 mm (p > 0.05) during smiling. No gender differences in mobility were identified (p > 0.05).ConclusionThe results obtained are in line with previous cadaveric investigations and revealed, in a highly statistically significant fashion, that the superficial midfacial fat compartments move in cranial direction whereas the deep fat compartment did not display similar positional changes. These results help to guide facial injectable treatments and to understand why, in the midface, a deep supraperiosteal approach should be favored when augmenting the deep midfacial fat compartments.