Bilgili, Ahmet

ABSTRACTBackgroundEvolving trends in organ procurement and technological innovation prompted an investigation into recent trends, indications, and outcomes following combined heart–lung transplantation (HLTx).MethodsThe United Network for Organ Sharing database was queried for all adult (≥18 years) HLTx performed between July 1, 2013 and June 30, 2023. Patients with previous transplants were excluded. The primary endpoint was the effect of donor, recipient, and transplantation characteristics on 1‐ and 5‐year survival. Secondary analyses included a comparison of HLTx at high‐ and low‐volume centers, an assessment of HLTx following donation after circulatory death (DCD), and an evaluation of HLTx volume over time. Cox proportional‐hazards models were used to assess factors associated with mortality. Temporal trends were evaluated with linear regression.ResultsAfter exclusions, 319 patients were analyzed, of whom 5 (1.6%) were DCD. HLTx volume increased from 2013 to 2023 (p < 0.001). One‐ and 5‐year survival following HLTx was 84.0% and 59.5%, respectively. One‐year survival was higher for patients undergoing HLTx at a high‐volume center (88.3% vs. 77.9%; p = 0.012). After risk adjustment, extracorporeal membrane oxygenation support 72 h posttransplant and predischarge dialysis were associated with increased 1‐year mortality (HR = 3.19, 95% CI = 1.86–5.49 and HR = 3.47, 95% CI = 2.17–5.54, respectively) and 5‐year mortality (HR = 2.901, 95% CI = 1.679–5.011 and HR = 3.327, 95% CI = 2.085–5.311, respectively), but HLTx at a high‐volume center was not associated with either.ConclusionsHLTx volume has resurged, with DCD HLTx emerging as a viable procurement strategy. Factors associated with 1‐ and 5‐year survival may be used to guide postoperative management following HLTx.

Abstract Metastatic castration-resistant prostate cancer (mCRPC) is an aggressive malignancy with poor outcomes. To investigate novel therapeutic strategies, we characterized three new metastatic prostate cancer patient derived-tumor xenograft (PDTX) models and developed 3D spheroids from each to investigate molecular targeted therapy combinations including CDK4/6 inhibitors (CDK4/6i) with AKT inhibitors (ATKi). Metastatic prostate cancer tissue was collected and three PDTX models were established and characterized using whole-exome sequencing. PDTX 3D spheroids were developed from these three PDTXs to show resistance patterns and test novel molecular-targeted therapies. CDK4/6i's were combined with AKTi's to assess synergistic antitumor response to prove our hypothesis that blockade of AKT overcomes drug resistance to CDK4/6i. This combination was evaluated in PDTX three-dimensional (3D) spheroids and in vivo experiments with responses measured by tumor volumes, PSA, and Ga-68 PSMA-11 PET-CT imaging. We demonstrated CDK4/6i's with AKTi's possess synergistic antitumor activity in three mCRPC PDTX models. These models have multiple unique pathogenic and deleterious genomic alterations with resistance to single-agent CDK4/6i's. Despite this, combination therapy with AKTi's was able to overcome resistance mechanisms. The IHC and Western blot analysis confirmed on target effects, whereas tumor volume, serum PSA ELISA, and radionuclide imaging demonstrated response to therapy with statistically significant SUV differences seen with Ga-68 PSMA-11 PET-CT. These preclinical data demonstrating antitumor synergy by overcoming single-agent CDK 4/6i as well as AKTi drug resistance provide the rational for a clinical trial combining a CDK4/6i with an AKTi in patients with mCRPC whose tumor expresses wild-type retinoblastoma 1.

(1) Background: Mutations in NFκB1, a transcriptional regulator of immunomodulating proteins, are a known cause of inborn errors of immunity. Our proband is a 22-year-old male with a diagnosis of common variable immunodeficiency (CVID), cytopenias with massive splenomegaly, and nodular regenerative hyperplasia of the liver. Genetic studies identified a novel, single-point mutation variant in NFκB1, c. T638A p. V213E. (2) Methods: Next-generation panel sequencing of the patient uncovered a novel single-point mutation in the NFκB1 gene that was modeled using the I-TASSER homology-modeling software, and molecular dynamics were assessed using the YASARA2 software (version 20.14.24). (3) Results: This variant replaces valine with glutamic acid at position 213 in the NFκB1 sequence. Molecular modeling and molecular dynamic studies showed altered dynamics in and around the rel homology domain, ankyrin regions, and death domain of the protein. We postulate that these changes alter overall protein function. (4) Conclusions: This case suggests the pathogenicity of a novel variant using protein-modeling techniques and molecular dynamic simulations.

Abstract Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Tyrosine kinase inhibitors (TKIs) are approved as a first-line treatment for unresectable HCC. Lenvatinib and cabozantinib are two of the most used TKIs, but the therapeutic duration is limited due to the development of drug resistance. Therefore, understanding the mechanisms of resistance and combining TKIs with other drugs antagonizing resistance should lead to antitumor synergy, eliminating drug resistance. It turns out that the simultaneous use of TKIs together with an inhibitor of stearoyl-CoA desaturase 1 (SCD1) prevents the development of drug resistance, leading to a durable response. SCD1 is the enzyme responsible for de novo fatty acid (FAs) synthesis, converting saturated fatty acids (SFAs) into monounsaturated fatty acids (MUFAs). MUFAs are an alternative energy source to glucose, integral to cellular membranes, and prevent endoplasmic reticulum (ER) stress and other signaling pathways. In our laboratory, we developed a novel, highly specific SCD1 inhibitor - SSI-4. We have tested the biological activity of SSI-4 against different HCC cell lines and patient-derived xenografts (PDX) mouse models. Of the twelve tested HCC cell lines, four were highly sensitive to SSI-4 (IC50 1-50 nM). Other cell lines showed moderate or no sensitivity to SSI-4. We tested the concomitant use of SSI-4 with lenvatinib and cabozantinib, tyrosine kinase inhibitors (TKIs) FDA-approved for HCC, in HCC cell lines in vitro and using HCC PDX in vivo mouse models. Our studies showed that the combination of the SCD1 inhibitor with both lenvatinib and cabozantinib showed a highly synergistic effect and no development of drug resistance i.e. durable response versus single TKI therapy. Ongoing mechanistic studies are examining whether known molecular targets of tested TKI’s such as VEGFR1, 2, and 3, PDGFRα, FGFR, KIT, and RET dominate in HCC drug resistance to lenvatinib and cabozantinib, and how the use of SSI-4 overcomes the phenomenon of resistance. Citation Format: Justyna J. Gleba, Aylin Alasonyalilar-Demirer, Matthew L. Pawlush, Ahmet Bilgili, Peyton G. Hickman, Kabir Mody, Lewis R. Roberts, Steven R. Alberts, Mark J. Truty, Tushar C. Patel, Han W. Tun, John A. Copland. Synergistic activity of SCD1 blockade in combination with tyrosine kinase inhibitors lenvatinib and cabozantinib in hepatocellular carcinoma (HCC). [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5489.