Mutagenesis, Hydrogen-Deuterium Exchange, and Molecular Docking Investigations Establish the Dimeric Interface of Human Platelet-Type 12-Lipoxygenase.

It was previously shown that human platelet 12S-lipoxygenase (h12-LOX) exists as a dimer; however, the specific structure is unknown. In this study, we create a model of the dimer through a combination of computational methods, experimental mutagenesis, and hydrogen-deuterium exchange (HDX) investigations. Initially, Leu183 and Leu187 were replaced by negatively charged glutamate residues and neighboring aromatic residues were replaced with alanine residues (F174A/W176A/L183E/L187E/Y191A). This quintuple mutant disrupted both the hydrophobic and π-π interactions, generating an h12-LOX monomer. To refine the determinants for dimer formation further, the L183E/L187E mutant was generated and the equilibrium shifted mostly toward the monomer. We then submitted the predicted monomeric structure to protein-protein docking to create a model of the dimeric complex. A total of nine of the top 10 most energetically favorable docking conformations predict a TOP-to-TOP dimeric arrangement of h12-LOX, with the α-helices containing a Leu-rich region (L172, L183, L187, and L194), corroborating our experimental results showing the importance of these hydrophobic interactions for dimerization. This model was supported by HDX investigations that demonstrated the stabilization of four, non-overlapping peptides within helix α2 of the TOP subdomain for wt-h12-LOX, consistent with the dimer interface. Most importantly, our data reveal that the dimer and monomer of h12-LOX have distinct biochemical properties, suggesting that the structural changes due to dimerization have allosteric effects on active site catalysis and inhibitor binding.

Photodynamic Therapy for Glioblastoma: Illuminating the Path toward Clinical Applicability.

Glioblastoma (GBM) is the most common adult brain cancer. Despite extensive treatment protocols comprised of maximal surgical resection and adjuvant chemo-radiation, all glioblastomas recur and are eventually fatal. Emerging as a novel investigation for GBM treatment, photodynamic therapy (PDT) is a light-based modality that offers spatially and temporally specific delivery of anti-cancer therapy with limited systemic toxicity, making it an attractive option to target GBM cells remaining beyond the margins of surgical resection. Prior PDT approaches in GBM have been predominantly based on 5-aminolevulinic acid (5-ALA), a systemically administered drug that is metabolized only in cancer cells, prompting the release of reactive oxygen species (ROS), inducing tumor cell death via apoptosis. Hence, this review sets out to provide an overview of current PDT strategies, specifically addressing both the potential and shortcomings of 5-ALA as the most implemented photosensitizer. Subsequently, the challenges that impede the clinical translation of PDT are thoroughly analyzed, considering relevant gaps in the current PDT literature, such as variable uptake of 5-ALA by tumor cells, insufficient tissue penetrance of visible light, and poor oxygen recovery in 5-ALA-based PDT. Finally, novel investigations with the potential to improve the clinical applicability of PDT are highlighted, including longitudinal PDT delivery, photoimmunotherapy, nanoparticle-linked photosensitizers, and near-infrared radiation. The review concludes with commentary on clinical trials currently furthering the field of PDT for GBM. Ultimately, through addressing barriers to clinical translation of PDT and proposing solutions, this review provides a path for optimizing PDT as a paradigm-shifting treatment for GBM.

Small Cell Lung Cancer Transformation following Treatment in EGFR-Mutated Non-Small Cell Lung Cancer.

EGFR-mutated lung adenocarcinoma patients who received tyrosine kinase inhibitors (TKIs) may initially respond to therapy, but over time, resistance eventually occurs. In a small population (5-10%), these patients can have a histological transformation to SCLC. Nine patients with EGFR-mutated lung adenocarcinoma who transformed to SCLC were evaluated at City of Hope. Patient clinical and pathology data, including multiple next-generation sequencing (NGS) results, clinical therapies, histology, and outcomes, were collected across multiple time points. Descriptive statistics were utilized to visualize and interpret the clinical therapeutic timeline and molecular transformation profiles for these patients. All patients received at least one line of EGFR TKI therapies prior to small cell lung cancer transformation, including erlotinib, afatinib, and osimertinib. Two patients also received chemotherapy prior to transformation (one with immunotherapy). The median months to small cell lung cancer transformation was 16 months, ranging from 4-49 months. The median overall survival (OS) was 29 months from diagnosis, with the minimum of 16 months and maximum of 62 months. The majority of patients had EGFR exon 19 deletion (n = 7, 77.8%), and no patients had a change of original oncogenic EGFR mutation over the different time points. Though a TP53 mutation was detected in eight patients (88.9%) either at the first biopsy or the subsequent biopsies, an RB1 alteration was only detected in one patient at presentation, and three patients upon subsequent biopsies (n = 4, 44.4%). Each patient had a unique molecular profile in the subsequent molecular testing post-transformation, but BRAF alterations occurred frequently, including BRAF rearrangement (n = 1), fusion (n = 1), and amplification (n = 1). Our results showed that EGFR-mutated lung adenocarcinoma to SCLC transformation patients have a unique histological, molecular, and clinical profile over multiple time points, with further heterogeneity that is not currently reported in the literature, and we suggest more work is required to better understand the molecular heterogeneity and clinical outcomes over time for this EGFR TKI resistance subtype.

Elevated Eosinophil Count Following Pembrolizumab Treatment for Non-Small Cell Lung Cancer.

Immune-related adverse events (IRAEs) are a common yet problematic phenomenon in patients who are treated with immune checkpoint inhibitors (ICIs). Current research efforts have explored the exact pathophysiology of IRAEs in the clinical setting. However, a rare subset of IRAEs that is less highlighted and may cause detrimental effects are hematological IRAEs (heme-IRAEs). Of note, immune-induced eosinophilia itself is a heme-IRAE that is worthy of further investigation. In this report, we present two cases of advanced staged non-small cell lung cancer (NSCLC) treated with single-agent pembrolizumab, and who subsequently sustained markedly elevated eosinophil counts (EEC) on laboratory findings. The two patients were Caucasian and both were diagnosed with NSCLC, although with differing histologies: a 76-year-old male with adenocarcinoma and a 66-year-old female with squamous cell carcinoma. Programmed death-ligand 1 (PD-L1) expression was detected via immunohistochemistry (IHC) and molecular tumor profiling did not show any actionable oncogenic mutations. Both patients were treatment-naïve and received pembrolizumab as first-line systemic therapy. The male patient, a former heavy smoker, underwent 18 months of pembrolizumab treatment before high eosinophil counts and was diagnosed with immunotherapy-related apoptotic colopathy after colonoscopy. Following pembrolizumab discontinuation, he remains under surveillance with good disease control and does not show any ongoing symptoms. The female patient, a never-smoker, underwent 15 cycles of pembrolizumab before the discontinuation of the treatment after consistently high levels of eosinophil counts. Both patients were treated with systemic corticosteroids after the discontinuation of immunotherapy, and their eosinophil levels returned to normal values. However, the female patient declined any further therapy and expired 24 months after the discontinuation of immunotherapy. Immune-induced eosinophilia is a rare event and reported in only 2.9% of NSCLC cases. Outcomes in the two patients differed, indicating that further research related to eosinophilia and its causes in the context of varying histologies and clinical profiles of patients is warranted.

Molecular and Clinical Features of Hospital Admissions in Patients with Thoracic Malignancies on Immune Checkpoint Inhibitors.

Lung cancer patients undergoing systemic treatment with immune checkpoint inhibitors (ICIs) can lead to severe immune-related adverse events (irAEs) that may warrant immediate hospitalization. Patients with thoracic malignancies hospitalized at City of Hope while undergoing treatment with ICIs were identified. Pathology and available next-generation sequencing (NGS) data, including the programmed death-ligand 1 (PD-L1) status and clinical information, including hospitalizations, invasive procedures, and the occurrence of irAEs, were collected. Unpaired T-tests, Chi-square/Fisher's exact test, and logistic regression were used to analyze our cohort. The overall survival (OS) was calculated and compared using univariate and multivariate COX models. Ninety patients with stage IV lung cancer were admitted after ICI treatment. Of those patients, 28 (31.1%) had documented irAEs. Genomic analyses showed an enrichment of LRP1B mutations (n = 5/6 vs. n = 7/26, 83.3% vs. 26.9%; odds ratio (OR) (95% confidence interval (CI): 13.5 (1.7-166.1); p < 0.05) and MLL3 mutations (n = 4/6, 66.7% vs. n = 5/26, 19.2%; OR (95% CI): 8.4 (1.3-49.3), p < 0.05) in patients with irAE occurrences. Patients with somatic genomic alterations (GAs) in MET (median OS of 2.7 vs. 7.2 months; HR (95% CI): 3.1 (0.57-17.1); p < 0.05) or FANCA (median OS of 3.0 vs. 12.4 months; HR (95% CI): 3.1 (0.70-13.8); p < 0.05) demonstrated a significantly shorter OS. Patients with irAEs showed a trend toward improved OS (median OS 16.4 vs. 6.8 months, p = 0.19) compared to hospitalized patients without documented irAEs. Lung cancer patients who required treatment discontinuance or interruption due to irAEs (n = 19) had significantly longer OS (median OS 18.5 vs. 6.2 months; HR (95% CI): 0.47 (0.28-0.79); p < 0.05). Our results showed a significant survival benefit in lung cancer patients hospitalized due to irAEs that necessitated a treatment interruption. Patients with positive somatic GAs in MET and FANCA were associated with significantly worse OS compared to patients with negative GAs.

Evaluation of Omics-Based Strategies for the Management of Advanced Lung Cancer.

PURPOSE: Omic-informed therapy is being used more frequently for patients with non-small-cell lung cancer (NSCLC) being treated on the basis of evidence-based decision-making. However, there is a lack of a standardized framework to evaluate those decisions and understand the association between omics-based management strategies and survival among patients. Therefore, we compared outcomes between patients with lung adenocarcinoma who received omics-driven targeted therapy versus patients who received standard therapeutic options. PATIENTS AND METHODS: This was a retrospective study of patients with advanced NSCLC adenocarcinoma (N = 798) at City of Hope who received genomic sequencing at the behest of their treating oncologists. A thoracic oncology registry was used as a clinicogenomic database to track patient outcomes. RESULTS: Of 798 individuals with advanced NSCLC (median age, 65 years [range, 22-99 years]; 60% white; 50% with a history of smoking), 662 patients (83%) had molecular testing and 439 (55%) received targeted therapy on the basis of the omic-data. A fast-and-frugal decision tree (FFT) model was developed to evaluate the impact of omics-based strategy on decision-making, progression-free survival (PFS), and overall survival (OS). We calculated that the overall positive predictive value of the entire FFT strategy for predicting decisions regarding the use of tyrosine kinase inhibitor-based targeted therapy was 88% and the negative predictive value was 96%. In an adjusted Cox regression analysis, there was a significant correlation with survival benefit with the FFT omics-driven therapeutic strategy for both PFS (hazard ratio [HR], 0.56; 95% CI, 0.42 to 0.74; P < .001) and OS (HR, 0.51; 95% CI, 0.36 to 0.71; P < .001) as compared with standard therapeutic options. CONCLUSION: Among patients with advanced NSCLC who received care in the academic oncology setting, omics-driven therapy decisions directly informed treatment in patients and was correlated with better OS and PFS.

Evaluation of Somatic Mutations in Solid Metastatic Pan-Cancer Patients.

Metastasis continues to be the primary cause of all cancer-related deaths despite the recent advancements in cancer treatments. To evaluate the role of mutations in overall survival (OS) and treatment outcomes, we analyzed 957 metastatic patients with seven major cancer types who had available molecular testing results with a FoundationOne CDx® panel. The most prevalent genes with somatic mutations were TP53, KRAS, APC, and LRP1B. In this analysis, these genes had mutation frequencies higher than in publicly available datasets. We identified that the somatic mutations were seven mutually exclusive gene pairs and an additional fifty-two co-occurring gene pairs. Mutations in the mutually exclusive gene pair APC and CDKN2A showed an opposite effect on the overall survival. However, patients with CDKN2A mutations showed significantly shorter OS (HR: 1.72, 95% CI: 1.34-2.21, p < 0.001) after adjusting for cancer type, age at diagnosis, and sex. Five-year post metastatic diagnosis survival analysis showed a significant improvement in OS (median survival 28 and 43 months in pre-2015 and post-2015 metastatic diagnosis, respectively, p = 0.00021) based on the year of metastatic diagnosis. Although the use of targeted therapies after metastatic diagnosis prolonged OS, the benefit was not statistically significant. However, longer five-year progression-free survival (PFS) was significantly associated with targeted therapy use (median 10.9 months (CI: 9.7-11.9 months) compared to 9.1 months (CI: 8.1-10.1 months) for non-targeted therapy, respectively, p = 0.0029). Our results provide a clinically relevant overview of the complex molecular landscape and survival mechanisms in metastatic solid cancers.

Complex Oncological Decision-Making Utilizing Fast-and-Frugal Trees in a Community Setting-Role of Academic and Hybrid Modeling.

Non-small cell lung cancer is a devastating disease and with the advent of targeted therapies and molecular testing, the decision-making process has become complex. While established guidelines and pathways offer some guidance, they are difficult to utilize in a busy community practice and are not always implemented in the community. The rationale of the study was to identify a cohort of patients with lung adenocarcinoma at a City of Hope community site (n = 11) and utilize their case studies to develop a decision-making framework utilizing fast-and-frugal tree (FFT) heuristics. Most patients had stage IV (N = 9, 81.8%) disease at the time of the first consultation. The most common symptoms at initial presentation were cough (N = 5, 45.5%), shortness of breath (N = 3, 27.2%), and weight loss (N = 3, 27.2%). The Eastern Cooperative Oncology Group (ECOG) performance status ranged from 0-1 in all patients in this study. Distribution of molecular drivers among the patients were as follows: EGFR (N = 5, 45.5%), KRAS (N = 2, 18.2%), ALK (N = 2, 18.2%), MET (N = 2, 18.2%), and RET (N = 1, 9.1%). Seven initial FFTs were developed for the various case scenarios, but ultimately the decisions were condensed into one FFT, a molecular stage IV FFT, that arrived at accurate decisions without sacrificing initial information. While these FFT decision trees may seem arbitrary to an experienced oncologist at an academic site, the simplicity of their utility is essential for community practice where patients often do not get molecular testing and are not assigned proper therapy.