Durvalumab plus pazopanib combination in patients with advanced soft tissue sarcomas: a phase II trial

We aimed to determine the activity of the anti-VEGF receptor tyrosine-kinase inhibitor, pazopanib, combined with the anti-PD-L1 inhibitor, durvalumab, in metastatic and/or recurrent soft tissue sarcoma (STS). In this single-arm phase 2 trial (NCT03798106), treatment consisted of pazopanib 800 mg orally once a day and durvalumab 1500 mg once every 3 weeks. Primary outcome was overall response rate (ORR) and secondary outcomes included progression-free survival (PFS), overall survival, disease control rate, immune-related response criteria, and safety. The ORR was 30.4% and the trial met the pre-specified endpoint. The median PFS was 7.7 months (95% confidence interval: 5.7-10.4). The common treatment-related adverse events of grades 3-4 included neutropenia (9 [19.1%]), elevated aspartate aminotransferase (7 [14.9%]), alanine aminotransferase (5 [10.6%]), and thrombocytopenia (4 [8.5%]). In a prespecified transcriptomic analysis, the B lineage signature was a significant key determinant of overall response (P = 0.014). In situ analysis also showed that tumours with high CD20+ B cell infiltration and vessel density had a longer PFS (P = 6.5 × 10-4) than those with low B cell infiltration and vessel density, as well as better response (50% vs 12%, P = 0.019). CD20+ B cell infiltration was identified as the only independent predictor of PFS via multivariate analysis. Durvalumab combined with pazopanib demonstrated promising efficacy in an unselected STS cohort, with a manageable toxicity profile.

Genetic landscape and PD-L1 expression in Epstein-Barr virus-associated gastric cancer according to the histological pattern

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is a distinct molecular subtype of gastric cancer. This study aims to investigate genomic and clinicopathological characteristics of EBVaGC according to the histological pattern. We retrospectively collected 18 specimens of surgically resected EBVaGCs. Whole-exome sequencing was performed for all cases. Moreover, PD-L1 expression and tumor-infiltrating lymphocyte (TIL) percentage were investigated. Among 18 EBVaGCs, 10 cases were of intestinal histology, 3 were of poorly cohesive histology, and the remaining 5 were of gastric carcinoma with lymphoid stroma histology. Whole-exome sequencing revealed that EBVaGCs with intestinal histology harbored pathogenic mutations known to frequently occur in tubular or papillary adenocarcinoma, including TP53, KRAS, FBXW7, MUC6, ERBB2, CTNNB1, and ERBB2 amplifications. One patient with poorly cohesive carcinoma histology harbored a CDH1 mutation. Patients with EBVaGCs with intestinal or poorly cohesive carcinoma histology frequently harbored driver mutations other than PIK3CA, whereas those with EBVaGCs with gastric carcinoma with lymphoid stroma histology lacked other driver mutations. Moreover, the histological pattern of EBVaGCs was significantly associated with the levels of TILs (P = 0.005) and combined positive score (P = 0.027). In conclusion, patients with EBVaGCs with different histological patterns exhibited distinct genetic alteration, PD-L1 expression, and degree of TILs.

The semaphorin 3A/neuropilin-1 pathway promotes clonogenic growth of glioblastoma via activation of TGF-β signaling

Glioblastoma (GBM) is the most lethal brain cancer with a dismal prognosis. Stem-like GBM cells (GSCs) are a major driver of GBM propagation and recurrence; thus, understanding the molecular mechanisms that promote GSCs may lead to effective therapeutic approaches. Through in vitro clonogenic growth-based assays, we determined mitogenic activities of the ligand molecules that are implicated in neural development. We have identified that semaphorin 3A (Sema3A), originally known as an axon guidance molecule in the CNS, promotes clonogenic growth of GBM cells but not normal neural progenitor cells (NPCs). Mechanistically, Sema3A binds to its receptor neuropilin-1 (NRP1) and facilitates an interaction between NRP1 and TGF-β receptor 1 (TGF-βR1), which in turn leads to activation of canonical TGF-β signaling in both GSCs and NPCs. TGF-β signaling enhances self-renewal and survival of GBM tumors through induction of key stem cell factors, but it evokes cytostatic responses in NPCs. Blockage of the Sema3A/NRP1 axis via shRNA-mediated knockdown of Sema3A or NRP1 impeded clonogenic growth and TGF-β pathway activity in GSCs and inhibited tumor growth in vivo. Taken together, these findings suggest that the Sema3A/NRP1/TGF-βR1 signaling axis is a critical regulator of GSC propagation and a potential therapeutic target for GBM.

Identifying predictors of glioma evolution from longitudinal sequencing

Clonal evolution drives cancer progression and therapeutic resistance. Recent studies have revealed divergent longitudinal trajectories in gliomas, but early molecular features steering posttreatment cancer evolution remain unclear. Here, we collected sequencing and clinical data of initial-recurrent tumor pairs from 544 adult diffuse gliomas and performed multivariate analysis to identify early molecular predictors of tumor evolution in three diffuse glioma subtypes. We found that CDKN2A deletion at initial diagnosis preceded tumor necrosis and microvascular proliferation that occur at later stages of IDH-mutant glioma. Ki67 expression at diagnosis was positively correlated with acquiring hypermutation at recurrence in the IDH-wild-type glioma. In all glioma subtypes, MYC gain or MYC-target activation at diagnosis was associated with treatment-induced hypermutation at recurrence. To predict glioma evolution, we constructed CELLO2 (Cancer EvoLution for LOngitudinal data version 2), a machine learning model integrating features at diagnosis to forecast hypermutation and progression after treatment. CELLO2 successfully stratified patients into subgroups with distinct prognoses and identified a high-risk patient group featured by MYC gain with worse post-progression survival, from the low-grade IDH-mutant-noncodel subtype. We then performed chronic temozolomide-induction experiments in glioma cell lines and isogenic patient-derived gliomaspheres and demonstrated that MYC drives temozolomide resistance by promoting hypermutation. Mechanistically, we demonstrated that, by binding to open chromatin and transcriptionally active genomic regions, c-MYC increases the vulnerability of key mismatch repair genes to treatment-induced mutagenesis, thus triggering hypermutation. This study reveals early predictors of cancer evolution under therapy and provides a resource for precision oncology targeting cancer dynamics in diffuse gliomas.

Tissue factor is a critical regulator of radiation therapy-induced glioblastoma remodeling

Radiation therapy (RT) provides therapeutic benefits for patients with glioblastoma (GBM), but inevitably induces poorly understood global changes in GBM and its microenvironment (TME) that promote radio-resistance and recurrence. Through a cell surface marker screen, we identified that CD142 (tissue factor or F3) is robustly induced in the senescence-associated β-galactosidase (SA-βGal)-positive GBM cells after irradiation. F3 promotes clonal expansion of irradiated SA-βGal+ GBM cells and orchestrates oncogenic TME remodeling by activating both tumor-autonomous signaling and extrinsic coagulation pathways. Intratumoral F3 signaling induces a mesenchymal-like cell state transition and elevated chemokine secretion. Simultaneously, F3-mediated focal hypercoagulation states lead to activation of tumor-associated macrophages (TAMs) and extracellular matrix (ECM) remodeling. A newly developed F3-targeting agent potently inhibits the aforementioned oncogenic events and impedes tumor relapse in vivo. These findings support F3 as a critical regulator for therapeutic resistance and oncogenic senescence in GBM, opening potential therapeutic avenues.

Three-dimensional micromorphology of human midpalatal suture and pterygomaxillary articular complex

BACKGROUND

Sutures exist in the craniofacial area, and the pattern of maturation and synostosis of facial sutures is largely unknown.

METHODS

For a comprehensive understanding of the three-dimensional circummaxillary suture micromorphology, human midpalatal suture (MPS) and pterygomaxillary articular complex from eight subjects' (five males, three females, 72-88 years old) autopsies were longitudinally scanned with microcomputed tomography. Additional histology was performed for hematoxylin and eosin staining. Sutural micromorphology was assessed by interdigitation index (II), obliteration index (OI) and obliteration number. Intergroup comparisons were performed with Kruskal-Wallis and Mann-Whitney U with Bonferroni correction (α = 0.005). Correlation with anteroposterior and craniocaudal gradients was assessed with Spearman's correlation test (α = 0.05).

RESULTS

Maxillary region of MPS presented a higher II 1.50 (0.61) and obliteration number per slice 8 (9) (P < 0.005). OI was increased in palatomaxillary 35% (47%) followed by pterygopalatine suture 25% (49%) (P < 0.005). The II and OI of the MPS exhibited only a weak anteroposterior gradient, with relatively low correlations. Obliteration areas were found sporadically along the entire MPS.

CONCLUSIONS

Based on these findings, it is conceivable that the success of nonsurgical maxillary expansion largely depends on individual variations in sutural morphology and maturation rather than appliance design.

Pharmacogenomic profiling reveals molecular features of chemotherapy resistance in IDH wild-type primary glioblastoma

BACKGROUND

Although temozolomide (TMZ) has been used as a standard adjuvant chemotherapeutic agent for primary glioblastoma (GBM), treating isocitrate dehydrogenase wild-type (IDH-wt) cases remains challenging due to intrinsic and acquired drug resistance. Therefore, elucidation of the molecular mechanisms of TMZ resistance is critical for its precision application.

METHODS

We stratified 69 primary IDH-wt GBM patients into TMZ-resistant (n = 29) and sensitive (n = 40) groups, using TMZ screening of the corresponding patient-derived glioma stem-like cells (GSCs). Genomic and transcriptomic features were then examined to identify TMZ-associated molecular alterations. Subsequently, we developed a machine learning (ML) model to predict TMZ response from combined signatures. Moreover, TMZ response in multisector samples (52 tumor sectors from 18 cases) was evaluated to validate findings and investigate the impact of intra-tumoral heterogeneity on TMZ efficacy.

RESULTS

In vitro TMZ sensitivity of patient-derived GSCs classified patients into groups with different survival outcomes (P = 1.12e-4 for progression-free survival (PFS) and 3.63e-4 for overall survival (OS)). Moreover, we found that elevated gene expression of EGR4, PAPPA, LRRC3, and ANXA3 was associated to intrinsic TMZ resistance. In addition, other features such as 5-aminolevulinic acid negative, mesenchymal/proneural expression subtypes, and hypermutation phenomena were prone to promote TMZ resistance. In contrast, concurrent copy-number-alteration in PTEN, EGFR, and CDKN2A/B was more frequent in TMZ-sensitive samples (Fisher's exact P = 0.0102), subsequently consolidated by multi-sector sequencing analyses. Integrating all features, we trained a ML tool to segregate TMZ-resistant and sensitive groups. Notably, our method segregated IDH-wt GBM patients from The Cancer Genome Atlas (TCGA) into two groups with divergent survival outcomes (P = 4.58e-4 for PFS and 3.66e-4 for OS). Furthermore, we showed a highly heterogeneous TMZ-response pattern within each GBM patient using in vitro TMZ screening and genomic characterization of multisector GSCs. Lastly, the prediction model that evaluates the TMZ efficacy for primary IDH-wt GBMs was developed into a webserver for public usage ( http://www.wang-lab-hkust.com:3838/TMZEP ).

CONCLUSIONS

We identified molecular characteristics associated to TMZ sensitivity, and illustrate the potential clinical value of a ML model trained from pharmacogenomic profiling of patient-derived GSC against IDH-wt GBMs.

ESRP1-regulated isoform switching of LRRFIP2 determines metastasis of gastric cancer

Although accumulating evidence indicates that alternative splicing is aberrantly altered in many cancers, the functional mechanism remains to be elucidated. Here, we show that epithelial and mesenchymal isoform switches of leucine-rich repeat Fli-I-interacting protein 2 (LRRFIP2) regulated by epithelial splicing regulatory protein 1 (ESRP1) correlate with metastatic potential of gastric cancer cells. We found that expression of the splicing variants of LRRFIP2 was closely correlated with that of ESRP1. Surprisingly, ectopic expression of the mesenchymal isoform of LRRFIP2 (variant 3) dramatically increased liver metastasis of gastric cancer cells, whereas deletion of exon 7 of LRRFIP2 by the CRISPR/Cas9 system caused an isoform switch, leading to marked suppression of liver metastasis. Mechanistically, the epithelial LRRFIP2 isoform (variant 2) inhibited the oncogenic function of coactivator-associated arginine methyltransferase 1 (CARM1) through interaction. Taken together, our data reveals a mechanism of LRRFIP2 isoform switches in gastric cancer with important implication for cancer metastasis.

Comprehensive Molecular Characterization of Soft Tissue Sarcoma for Prediction of Pazopanib-Based Treatment Response

Purpose

Even though pazopanib, a multitargeted tyrosine kinase inhibitor, has been approved for refractory soft tissue sarcoma (STS), little is known about the molecular determinants of the response to pazopanib. We performed integrative molecular characterization to identify potential predictors of pazopanib efficacy.

Materials and Methods

We obtained fresh pre-treatment tumor tissue from 35 patients with advanced STS receiving pazopanib-based treatment. Among those, 18 (51.4%) received pazopanib monotherapy, and the remaining 17 (48.6%) received pazopanib in combination with durvalumab, PD-L1 blockade. Whole-exome and transcriptome sequencing were performed for each tumor and patient germline DNA.

Results

Of the 35 patients receiving pazopanib-based treatment, 9 achieved a partial response (PR), resulting in an objective response rate (ORR) of 27.3%, and the median progression-free survival (PFS) was 6.0 months. Patients with CDK4 amplification (copy ratio tumor to normal > 2) exhibited shorter PFS (3.7 vs 7.9 months, p=2.09 x10-4) and a poorer response (ORR; 0% vs 33.3%) compared to those without a gene amplification (copy ratio ≤ 2). Moreover, non-responders demonstrated transcriptional activation of CDK4 via DNA amplification, resulting in cell cycle activation. In the durvalumab combination cohort, 7 (41.2%) of the 17 patients achieved a PR, and gene expression analysis revealed that durvalumab responders exhibited high immune/stromal cell infiltration, mainly comprising NK cells, compared to non-responders as well as increased expression of CD19, a B cell marker.

Conclusion

Despite the limitation of heterogeneity in the study population and treatment, we identified possible molecular predictors of pazopanib efficacy that can be employed in future clinical trials aimed at evaluating therapeutic strategies.

Recapitulated Crosstalk between Cerebral Metastatic Lung Cancer Cells and Brain Perivascular Tumor Microenvironment in a Microfluidic Co-Culture Chip

Non-small cell lung carcinoma (NSCLC), which affects the brain, is fatal and resistant to anti-cancer therapies. Despite innate, distinct characteristics of the brain from other organs, the underlying delicate crosstalk between brain metastatic NSCLC (BM-NSCLC) cells and brain tumor microenvironment (bTME) associated with tumor evolution remains elusive. Here, a novel 3D microfluidic tri-culture platform is proposed for recapitulating positive feedback from BM-NSCLC and astrocytes and brain-specific endothelial cells, two major players in bTME. Advanced imaging and quantitative functional assessment of the 3D tri-culture model enable real-time live imaging of cell viability and separate analyses of genomic/molecular/secretome from each subset. Susceptibility of multiple patient-derived BM-NSCLCs to representative targeted agents is altered and secretion of serpin E1, interleukin-8, and secreted phosphoprotein 1, which are associated with tumor aggressiveness and poor clinical outcome, is increased in tri-culture. Notably, multiple signaling pathways involved in inflammatory responses, nuclear factor kappa-light-chain-enhancer of activated B cells, and cancer metastasis are activated in BM-NSCLC through interaction with two bTME cell types. This novel platform offers a tool to elucidate potential molecular targets and for effective anti-cancer therapy targeting the crosstalk between metastatic cancer cells and adjacent components of bTME.

Odorant receptors in cancer

Odorant receptors (ORs), the largest subfamily of G protein-coupled receptors, detect odorants in the nose. In addition, ORs were recently shown to be expressed in many nonolfactory tissues and cells, indicating that these receptors have physiological and pathophysiological roles beyond olfaction. Many ORs are expressed by tumor cells and tissues, suggesting that they may be associated with cancer progression or may be cancer biomarkers. This review describes OR expression in various types of cancer and the association of these receptors with various types of signaling mechanisms. In addition, the clinical relevance and significance of the levels of OR expression were evaluated. Namely, levels of OR expression in cancer were analyzed based on RNA-sequencing data reported in the Cancer Genome Atlas; OR expression patterns were visualized using t-distributed stochastic neighbor embedding (t-SNE); and the associations between patient survival and levels of OR expression were analyzed. These analyses of the relationships between patient survival and expression patterns obtained from an open mRNA database in cancer patients indicate that ORs may be cancer biomarkers and therapeutic targets.

Increased risk of cardiovascular diseases in patients with chronic rhinosinusitis: a longitudinal follow-up study using a national health screening cohort

BACKGROUND

Chronic rhinosinusitis (CRS) is one of the most common chronic inflammatory diseases and is characterized by sinonasal inflammation that lasts longer than 12 weeks. Whether the effect of chronic inflammation caused by CRS on cardiovascular diseases (CVDs) is similar to its effect on other inflammatory disorders has not been thoroughly evaluated. We aimed to demonstrate whether CRS patients have a higher prevalence of CVDs, including stroke and ischemic heart disease (IHD).

METHODOLOGY

We compared the prevalence of various comorbidities between CRS and control participants through a case-control cohort study from 2002 to 2015 that included 514,866 participants. CRS (n=6,552) and control (n=26,208) participants who were over 40 years old were selected by matching age, sex, income, and area of residence at a 1:4 ratio.

RESULTS

A stratified Cox proportional hazards model was utilized to assess the hazard ratio (HR) of CRS for stroke and IHD. The HRs for stroke and IHD were significantly increased in CRS patients compared to controls after adjusting for obesity, alcohol consumption, smoking, systolic and diastolic blood pressure, fasting blood glucose, total cholesterol, hemoglobin, and Charlson Comorbidity Index (CCI) scores. The HR of stroke was significantly higher in the absence of nasal polyps than in the presence of nasal polyps. The HR of IHD was significantly increased in the CRS group regardless of the presence of nasal polyps.

CONCLUSIONS

This study showed that CRS participants had a significantly higher prevalence of stroke and IHD.

Hepatocellular carcinoma patients with high circulating cytotoxic T cells and intra-tumoral immune signature benefit from pembrolizumab: results from a single-arm phase 2 trial

BACKGROUND

A limited number of studies have characterized genomic properties of hepatocellular carcinoma (HCC) patients in response to anti-PD-1 immunotherapy.

METHODS

Herein, we performed comprehensive molecular characterization of immediate (D-42 to D-1) pre-treatment tumor biopsy specimens from 60 patients with sorafenib-failed HCC in a single-arm prospective phase II trial of pembrolizumab. Objective response rate was the primary efficacy endpoint. We used whole-exome sequencing, RNA sequencing, and correlative analysis. In addition, we performed single-cell RNA sequencing using peripheral blood mononuclear cells.

RESULTS

The overall response rate of pembrolizumab in sorafenib-failed HCC patients was 10% ([6/60] 95% CI, 2.4-17.6). In a univariate analysis using clinicopathological features, female gender, PD-L1 positivity, and low neutrophil-to-lymphocyte ratio (NLR) were identified as contributing factors to pembrolizumab response. Somatic mutations in CTNNB1 and genomic amplifications in MET were found only in non-responders. Transcriptional profiles through RNA sequencing identified that pembrolizumab responders demonstrated T cell receptor (TCR) signaling activation with expressions of MHC genes, indicating increased levels of T cell cytotoxicity. In single-cell sequencing from 10 pre- and post-treatment peripheral blood mononuclear cells (PBMCs), patients who achieved a partial response or stable disease exhibited immunological shifts toward cytotoxic CD8+ T cells. Conversely, patients with progressive disease showed an increased number of both CD14+ and CD16+ monocytes and activation of neutrophil-associated pathways.

CONCLUSIONS

Taken together, HCC patients with infiltration of cytotoxic T cells, along with increased active circulating CD8+ T cells during pembrolizumab treatment and down-regulation of neutrophil-associated markers, significantly benefited from pembrolizumab treatment.

TRIAL REGISTRATION

NCT#03163992 (first posted: May 23, 2017).

Macitentan improves antitumor immune responses by inhibiting the secretion of tumor-derived extracellular vesicle PD-L1

Extracellular vesicles (EVs) carrying tumor cell-derived programmed death-ligand 1 (PD-L1) interact with programmed death 1 (PD-1)-producing T cells, thus significantly lowering a patient's response to immune checkpoint blockade drugs. No drug that reinvigorates CD8+ T cells by suppressing EV PD-L1 has been approved for clinical usage. Here we have identified macitentan (MAC), an FDA-approved oral drug, as a robust booster of antitumor responses in CD8+ T cells by suppressing tumor cell-derived EV PD-L1.

Methods: EV was analyzed by the data from nanoparticle tracking, immunoblotting analyses, and nano-flow cytometry. Antitumor immunity was evaluated by luciferase assay and immune phenotyping using flow cytometry. Clinical relevance was analyzed using the cancer genome atlas database.

Results: MAC inhibited secretion of tumor-derived EV PD-L1 by targeting the endothelin receptor A (ETA) in breast cancer cells and xenograft models. MAC enhanced CD8+ T cell-mediated tumor killing by decreasing the binding of PD-1 to the EV PD-L1 and thus synergizing the effects of the anti-PD-L1 antibody. MAC also showed an anticancer effect in triple-negative breast cancer (TNBC)-bearing immunocompetent mice but not in nude mice. The combination therapy of MAC and anti-PD-L1 antibody significantly improved antitumor efficacy by increasing CD8+ T cell number and activity with decreasing Treg number in the tumors and draining lymph nodes in TNBC, colon, and lung syngeneic tumor models. The antitumor effect of MAC was reversed by injecting exogenous EV PD-L1. Notably, ETA level was strongly associated with the innate anti-PD-1 resistance gene signature and the low response to the PD-1/PD-L1 blockade.

Conclusion: These findings strongly demonstrate that MAC, already approved for clinical applications, can be used to improve and/or overcome the inadequate response to PD-1/PD-L1 blockade therapy.

Odorant G protein-coupled receptors as potential therapeutic targets for adult diffuse gliomas: a systematic analysis and review

Odorant receptors (ORs) account for about 60% of all human G protein-coupled receptors (GPCRs). OR expression outside of the nose has functions distinct from odor perception, and may contribute to the pathogenesis of disorders including brain diseases and cancers. Glioma is the most common adult malignant brain tumor and requires novel therapeutic strategies to improve clinical outcomes. Here, we outlined the expression of brain ORs and investigated OR expression levels in glioma. Although most ORs were not ubiquitously expressed in gliomas, a subset of ORs displayed glioma subtype-specific expression. Moreover, through systematic survival analysis on OR genes, OR51E1 (mouse Olfr558) was identified as a potential biomarker of unfavorable overall survival, and OR2C1 (mouse Olfr15) was identified as a potential biomarker of favorable overall survival in isocitrate dehydrogenase (IDH) wild-type glioma. In addition to transcriptomic analysis, mutational profiles revealed that somatic mutations in OR genes were detected in > 60% of glioma samples. OR5D18 (mouse Olfr1155) was the most frequently mutated OR gene, and OR5AR1 (mouse Olfr1019) showed IDH wild-type-specific mutation. Based on this systematic analysis and review of the genomic and transcriptomic profiles of ORs in glioma, we suggest that ORs are potential biomarkers and therapeutic targets for glioma.

Long-Term Outcomes of Transarterial Radioembolization for Large Single Hepatocellular Carcinoma: A Comparison to Resection

The surgical treatment for large hepatocellular carcinoma (HCC) remains controversial due to a high risk of recurrence after resection. This study aimed to compare long-term outcomes of transarterial radioembolization (TARE) with resection for patients with large HCC. Methods: This retrospective cohort study included a total of 557 patients who were initially treated with either resection (the resection group, n = 500) or TARE (the TARE group, n = 57) for large (≥5 cm) single nodular HCC at two tertiary centers in Korea. Patients with major portal vein tumor thrombosis or extrahepatic metastasis were excluded. The primary endpoint was overall survival (OS), and secondary endpoints were time to progression (TTP), time to intrahepatic progression (TTIP), and safety. Results: The resection group were younger (median, 60 years vs. 69 years) with smaller tumor size (median, 7.0 cm vs. 10.0 cm) (all P<0.05). After baseline characteristics were balanced using inverse probability of treatment weighting (IPTW), the TARE group showed comparable OS (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.40-2.43; P = 0.97), TTP (HR, 1.10; 95% CI, 0.55-2.20; P = 0.80), and TTIP (HR, 1.45; 95% CI, 0.72-2.93; P = 0.30) to the resection group. TARE was not an independent risk for OS (adjusted-HR, 1.04; 95% CI, 0.42-2.59; P = 0.93), TTP (adjusted-HR, 0.98; 95% CI, 0.50-1.95; P = 0.96), or TTIP (adjusted-HR, 1.30; 95% CI, 0.65-2.58; P = 0.46). The TARE group showed shorter hospital stay and fewer adverse events than the resection group. Conclusion: TARE showed comparable OS, TTP, and TTIP with better safety profile compared to surgical resection for large single nodular HCC.

Comparison of Overall Survival between Surgical Resection and Radiofrequency Ablation for Hepatitis B-Related Hepatocellular Carcinoma

Simple Summary

The effectiveness of surgical resection and radiofrequency ablation in early hepatocellular carcinoma is still controversial because previous studies show conflicting results. In addition, previous studies did not consider the antiviral treatment-related factors, even though there is now robust evidence that antiviral therapy is crucial for determining the prognosis of patients with chronic hepatitis B-related liver cancer. After adjusting for the antiviral treatment, we demonstrated that radiofrequency ablation may provide comparable overall survival to resection in the treatment of very early or early hepatocellular carcinoma, although recurrence-free survival is marginally shorter than in the resection group.

Abstract

It remains controversial whether surgical resection, compared to radiofrequency ablation (RFA), improves overall survival (OS) in patients with early hepatocellular carcinoma (HCC). This study aimed to compare OS after RFA with that after resection for HCC. This retrospective study included patients who underwent RFA or surgical resection as initial treatment for hepatitis B virus (HBV)-related HCC at a very early or early stage. A total of 761 patients (RFA, n = 194; resection, n = 567) from Seoul National University Hospital (Seoul, South Korea) and 1277 patients (RFA, n = 352; resection, n = 925) from the Korean Primary Liver Cancer Registry were included in the hospital and nationwide cohorts, respectively. Primary and secondary endpoints were OS and recurrence-free survival (RFS), respectively. Additional analysis was performed when the history of the antiviral treatment and the type of prescribed nucleos(t)ide analogue were confirmed. The rate of complications was compared between the two treatment groups in the hospital cohort. Baseline characteristics were balanced, using inverse probability of treatment weighting (IPTW). In the hospital cohort, the RFA group had a smaller mean tumor size (1.7 vs. 3.9 cm) but a higher proportion of cirrhotic patients than the resection group (85.6% vs. 63.1%) (both p < 0.01). During 81.0 (interquartile range, 62.3–107.1) months of follow-up, there was no difference in OS (adjusted hazard ratio (aHR) = 0.870, 95% confidence interval (CI) = 0.400–1.897, p = 0.73) and RFA was associated with shorter RFS (aHR = 1.562, 95% CI = 1.099–2.219, p = 0.01) after employing IPTW. Antiviral treatment was independently associated with longer OS (aHR = 0.444, 95% CI = 0.251–0.786, p = 0.01) as well as RFS (aHR = 0.544, 95% CI = 0.391–0.757, p < 0.01) in the hospital cohort. In the nationwide cohort, there was no difference in OS (aHR = 0.981, 95% CI = 0.661–1.456, p = 0.92) between the two treatment groups when adjusted for antiviral treatment, which was a negative independent risk factor for mortality (aHR = 0.655, 95% CI = 0.451–0.952, p = 0.03) after IPTW. Among patients treated with tenofovir (n = 96) or entecavir (n = 184) in the hospital cohort, there was no difference in either OS (aHR = 0.522, 95% CI = 0.058–4.724, p = 0.56) or RFS (aHR = 1.116, 95% CI = 0.738–1.688, p = 0.60). The overall incidence of complications was higher in the resection group (26.3%) than in the RFA group (13.9%) (p < 0.01). RFA may provide comparable OS to resection in the treatment of very early or early HCC with a lower rate of complications, although RFS is marginally shorter than in the resection group after adjusting for antiviral treatment. Regardless of the type of NA, antiviral treatment in patients with HBV-related HCC is strongly associated with both OS and RFS.

Comprehensive molecular profiling to predict clinical outcomes in pancreatic cancer

Background:

Pancreatic ductal adenocarcinoma (PDAC) has the worst prognosis among common cancers. The genomic landscape of PDAC is defined by four mutational pathways: kirsten rat sarcoma virus (KRAS), cellular tumor antigen p53 (TP53), cyclin dependent kinase inhibitor 2A (CDKN2A), and SMAD family member 4 (SMAD4). However, there is a paucity of data on the molecular features associated with clinical outcomes after surgery or chemotherapy.

Methods:

We performed comprehensive molecular characterization of tumor specimens from 83 patients with PDAC who received surgery, using whole-exome sequencing and ribonucleic acid sequencing on tumor and matched normal tissues derived from patients. We also systematically performed integrative analysis, combining genomic, transcriptomic, and clinical features to identify biomarkers and possible therapeutic targets.

Results:

KRAS (75%), TP53 (67%), CDKN2A (12%), SMAD4 (20%), and ring finger protein 43 (RNF43) (13%) were identified as significantly mutated genes. The tumor-specific transcriptome was classified into two clusters (tumor S1 and tumor S2), which resembled the Moffitt tumor classification. Tumor S1 displayed two distinct subclusters (S1-1 and S1-2). The transcriptome of tumor S1-1 overlapped with the exocrine-like (Collisson)/ADEX (Bailey) subtype, while tumor S1-2 mostly consisted of the classical (Collisson)/progenitor (Bailey) subtype. In the analysis of combinatorial gene alterations, concomitant mutations of KRAS with low-density lipoprotein receptor related protein 1B (LRP1B) were associated with significantly worse disease-free survival after surgery (p = 0.034). One patient (1.2%) was an ultrahypermutant with microsatellite instability. We also identified high protein kinase C lota (PRKCI) expression as an overlapping, poor prognostic marker between our dataset and the TCGA dataset.

Conclusion:

We identified potential prognostic biomarkers and therapeutic targets of patients with PDAC. Understanding these molecular aberrations that determine patient outcomes after surgery and chemotherapy has the potential to improve the treatment outcomes of PDAC patients.

Durvalumab and pazopanib in patients with advanced soft tissue sarcoma: A single-center, single-arm, phase 2 trial

11551

Background: Based on the central role played by the vascular endothelial growth factor receptor (VEGFR) in immunosuppression, we assessed the activity and safety of VEGFR inhibitor pazopanib plus anti-PD-L1 blockade durvalumab in soft tissue sarcoma (STS). Methods: We did a single-arm, single-center, phase 2 study that enrolled patients with metastatic or locally advanced STS aged 19 years or older, ECOG PS 0-1, with at least one measurable lesion, and received at least one previous line of systemic therapy. Patient were given pazopanib 800 mg orally daily and durvalumab 1500 mg intravenously for 60 min every 3 weeks. The primary endpoint was investigator-assessed objective response. Results: Between September 2019 and October 2020, 47 participants were enrolled, of whom 46 (97.9%) were evaluable for the efficacy analyses. With a median follow up of 12.3 months, complete and partial response (PR) was achieved in 1 (2.2%) and 12 (26.1%) patients, resulting in 28.3 % of objective response rate. Median time to achieve PR was 1.4 months and median duration of response was 11.0 months. The most common treatment-related adverse events of any grade include fatigue (20 [42.6%]), anorexia (17 [36.2%]), diarrhea (17 [36.2%]), and AST elevation (16, [34.0%]). Thirty-one patients (67.3%) had progressive disease, and the median progression free survival was 8.6 months (95% CI 3.6-13.6). Conclusions: Durvalumab and pazopanib showed encouraging activity in patients with advanced STS. Molecular predictors with whole exome and RNA sequencing will be presented. Clinical trial information: NCT03798106.

Determinants of Response and Intrinsic Resistance to PD-1 Blockade in Microsatellite Instability-High Gastric Cancer

Sequence alterations in microsatellites and an elevated mutational burden are observed in 20% of gastric cancers and associated with clinical response to anti-PD-1 antibodies. However, 50% of microsatellite instability-high (MSI-H) cancers are intrinsically resistant to PD-1 therapies. We conducted a phase II trial of pembrolizumab in patients with advanced MSI-H gastric cancer and included serial and multi-region tissue samples in addition to serial peripheral blood analyses. The number of whole-exome sequencing (WES)-derived nonsynonymous mutations correlated with antitumor activity and prolonged progression-free survival (PFS). Coupling WES to single-cell RNA sequencing, we identified dynamic tumor evolution with greater on-treatment collapse of mutational architecture in responders. Diverse T-cell receptor repertoire was associated with longer PFS to pembrolizumab. In addition, an increase in PD-1⁺ CD8⁺ T cells correlated with durable clinical benefit. Our findings highlight the genomic, immunologic, and clinical outcome heterogeneity within MSI-H gastric cancer and may inform development of strategies to enhance responsiveness. SIGNIFICANCE: This study highlights response heterogeneity within MSI-H gastric cancer treated with pembrolizumab monotherapy and underscores the potential for extended baseline and early on-treatment biomarker analyses to identify responders. The observed markers of intrinsic resistance have implications for patient stratification to inform novel combinations among patients with intrinsically resistant features.See related commentary by Fontana and Smyth, p. 2126.This article is highlighted in the In This Issue feature, p. 2113.

Severe Periodontal Disease Increases Acute Myocardial Infarction and Stroke: A 10-Year Retrospective Follow-up Study

This study aimed to evaluate the causal association of periodontal disease with acute myocardial infarction (AMI) and stroke, after controlling for various confounders among the Korean population. A retrospective cohort study using the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS) was performed during 2002 to 2015 (baseline: 2002 to 2005; follow-up: 2006 to 2015) in the Republic of Korea. A total of 298,128 participants with no history of AMI or stroke were followed up for 10 y. AMI and stroke were defined by a diagnosis using the International Classification of Diseases, 10th Revision (ICD-10) guideline. Periodontal condition was classified into 3 groups (healthy, moderate periodontal disease, severe periodontal disease [SPD]) using the combination of ICD codes, treatment codes in the NHIS, and recommendation of periodontal treatment by the dentists in HEALS. Various confounders, such as sociodemographic, behavioral, systemic, and oral health factors, including hypercholesterolemia, were considered. Multivariable Cox regression analysis was applied to estimate adjusted incidence rate ratio (adjusted hazard ratio [aHR]) based on person-year of periodontal condition for AMI, stroke, and nonfatal major adverse cardiovascular events (MACEs) encompassing AMI or stroke controlling for various confounders. Stratified analyses according to age group, sex, and toothbrushing frequency were also performed. After controlling for various confounders, participants with SPD compared with non-SPD participants had a higher incidence by 11% for AMI (aHR, 1.11; 95% confidence interval [CI], 1.02-1.20), by 3.5% for stroke (aHR, 1.035; 95% CI, 1.01-1.07), and by 4.1% for MACEs (aHR, 1.04; 95% CI, 1.01-1.07). The association of SPD with AMI and MACE was highly modified in females and adults aged 40 to 59 y. In the total Korean population, SPD increased total AMI events by 4.3%, total stroke events by 1.4%, and the total MACEs by 1.6%. Our data confirmed that SPD was causally associated with the new events of AMI and stroke.

Molecular profiling of Asian patients with advanced melanoma receiving check-point inhibitor treatment

Objective

Melanoma is major medical challenge and being able to monitor treatment response is critical. This study aimed to use molecular profiling of Asian patients with advanced melanoma who were receiving treatment with check-point inhibitors (CPIs) to identify novel biomarkers of tumor response.

Methods

Next-generation sequencing (NGS) was performed using tumor specimens collected from 178 Asian patients with metastatic melanoma receiving CPIs. The NGS data and clinical-pathological factors were analyzed for potential genetic biomarkers of tumor response to CPI treatment.

Results

The most common melanoma subtype was acral melanoma (40%), followed by cutaneous melanoma (32%), mucosal melanoma (26%), and others (2%). For calculation of treatment efficacy, 164 of the patients could be evaluated. The overall response rate was 45.7%, of which 41 cases exhibited complete responses (25.0%) and 34 showed partial responses (20.7%). There were no significant differences in tumor responses based on melanoma subtype (P = 0.295). Genetically, NRAS mutations, TP53 mutations, and NF2 deletions were significantly associated with resistance to CPIs (P < 0.05). In contrast, MYC and RPS6KB1 amplifications were associated with responsiveness to CPIs (P < 0.05). Median progression-free survival (PFS) for patients treated with CPIs was 5.9 months (95% CI, 3.8-8.05 months). Univariate analysis identified TP53 and BRAF mutations, NF2 deletions, and BIRC2 amplifications as poor prognostic factors for PFS (P < 0.05).

Conclusions

This study determined the integrated genomic profiles of Asian patients with metastatic melanoma receiving CPIs and identified candidate biomarkers that reflected treatment outcomes.

•

The molecular characterization of Asian melanoma patients receiving check-point inhibitors (CPIs) using NGS has not been reported.

•

NRAS and TP53 mutations and NF2 deletions were significantly associated with resistance to CPIs.

•

MYC and RPS6KB1 amplifications were associated with responsiveness to CPIs.

•

TP53 and BRAF mutations, NF2 deletions, and BIRC2 amplifications were poor prognostic factors for progression-free survival.

•

This is the largest integrated genomic study to date that identifying novel biomarkers of CPIs in Asian melanoma patients.

NIMG-20. MULTI-HABITAT RADIOMICS UNRAVELS DISTINCT PHENOTYPIC SUBTYPES OF GLIOBLASTOMA WITH CLINICAL AND GENOMIC SIGNIFICANCE

BACKGROUNDS

We aimed to evaluate the potential of radiomics as an imaging biomarker for GBM patients and explore the molecular rationale behind radiomics by radio-genomics approach.

METHODS

A total of 144 primary GBM patients were included in this study as a training cohort. Using multi-parametric MR images, radiomics features were extracted from multi-habitats of the tumor. We applied Cox-LASSO algorithm to build a survival prediction model and validated this model using an independent validation cohort (56 patients from Vienna). With the selected radiomics features, GBM patients were consensus clustered to reveal inherent phenotypic subtypes. The subtypes were further explored in terms of genomic signatures.

RESULTS

GBM patients were successfully stratified by the radiomics risk score, a weighted sum of radiomics features, corroborating the potential of radiomics as a prognostic biomarker. Using consensus clustering, we identified three distinct subtypes which significantly differed in the prognosis (‘heterogenous enhancing’, ‘rim-enhancing necrotic’, and ‘cystic’ subtype). Multi-variate cox regression analysis confirmed that radiomics subtype as an independent prognostic factor. Transcriptomic traits enriched in individual subtypes were in accordance with imaging phenotypes summarized by radiomics. For example, rim-enhancing necrotic subtype was well described by radiomics profiling (T2 autocorrelation & flat shape) and highlighted by the inflammatory genomic signatures, which well correlated to its phenotypic peculiarity (necrosis).

CONCLUSIONS

The present study confirmed the feasibility of radiomics as an imaging biomarker for GBM patients with comprehensible biologic annotation. Imaging subtypes derived from radiomics successfully recapitulate the genomic underpinnings of GBM tumors and in turn reinforce their potential as a prognostic biomarker.

Clinical and molecular distinctions in patients with refractory colon cancer who benefit from regorafenib treatment

Regorafenib (Stivarga, BAY 73-4506; Bayer Pharma AG, Berlin, Germany) is a novel oral multikinase inhibitor that blocks the activity of several protein kinases. However, few guidelines exist for novel biomarkers to select patients who will likely benefit from regorafenib treatment. Metastatic colorectal cancer (mCRC) patients treated with regorafenib were evaluated in this study. Tumor tissues of these patients were subjected to next-generation sequencing-based cancer panel tests. The relationship between molecular profiling and efficacy of regorafenib was analyzed. Among the 76 mCRC patients, the median age was 58 years (range 22–79 years), and 73.7% received regorafenib as a third-line therapy. The primary tumor locations were the right side (n = 15, 19.8%) and the left side (n = 61, 80.2%). Most patients (97.4%) had received prior anti-angiogenetic agents, and a prior anti-Epidermal Growth Factor Receptor (EGFR) agent had been administered to 32.9%. Of these 76 patients, 65 were evaluated to determine the efficacy of treatment. We observed zero complete responses, seven confirmed partial responses (PR 9.2%), 26 stable disease states (34.2%), and 32 disease progressions (42.1%). The overall confirmed response rate and the disease control rate were 9.2% and 43.4%, respectively. Genomic analysis revealed that APC mutations were significant in patients who demonstrated a tumor response to regorafenib (p < 0.05). Interestingly, FGFR1 amplification was detected in only three of 76 patients (3.9%), and these three patients achieved a PR to regorafenib. The median progression-free survival time was 2.8 months (95% Confidence Interval [CI] 1.6–4.0). Patients with BRAF mutation and/or SMAD4 mutation had significantly worse progression-free survival (PFS) than those without such a mutation. On pathway analysis, Tumor Growth Factor (TGF)-beta pathways were significantly associated with worse PFS. We found that efficacy of regorafenib might be correlated with specific genetic aberrations, such as APC mutation and FGFR1 amplification. In addition, SMAD4 mutation and TGF-beta pathway were associated with worse PFS after regorafenib. We found that efficacy of regorafenib might be correlated with specific genetic aberrations, such as APC mutation and FGFR1 amplification. In addition, SMAD4 mutation and the TGF-beta pathway were associated with worse PFS after regorafenib.

Transcriptional regulatory networks of tumor-associated macrophages that drive malignancy in mesenchymal glioblastoma

BACKGROUND

Glioblastoma (GBM) is a complex disease with extensive molecular and transcriptional heterogeneity. GBM can be subcategorized into four distinct subtypes; tumors that shift towards the mesenchymal phenotype upon recurrence are generally associated with treatment resistance, unfavorable prognosis, and the infiltration of pro-tumorigenic macrophages.

RESULTS

We explore the transcriptional regulatory networks of mesenchymal-associated tumor-associated macrophages (MA-TAMs), which drive the malignant phenotypic state of GBM, and identify macrophage receptor with collagenous structure (MARCO) as the most highly differentially expressed gene. MARCO^high TAMs induce a phenotypic shift towards mesenchymal cellular state of glioma stem cells, promoting both invasive and proliferative activities, as well as therapeutic resistance to irradiation. MARCO^high TAMs also significantly accelerate tumor engraftment and growth in vivo. Moreover, both MA-TAM master regulators and their target genes are significantly correlated with poor clinical outcomes and are often associated with genomic aberrations in neurofibromin 1 (NF1) and phosphoinositide 3-kinases/mammalian target of rapamycin/Akt pathway (PI3K-mTOR-AKT)-related genes. We further demonstrate the origination of MA-TAMs from peripheral blood, as well as their potential association with tumor-induced polarization states and immunosuppressive environments.

CONCLUSIONS

Collectively, our study characterizes the global transcriptional profile of TAMs driving mesenchymal GBM pathogenesis, providing potential therapeutic targets for improving the effectiveness of GBM immunotherapy.

Ethnic delineation of primary glioblastoma genome

Glioblastoma (GBM) is the most malignant primary brain tumor in adults with substantial genomic alterations. The median survival is approximately 14.6 months, despite aggressive therapeutic intervention, which comprised of surgical resection, radiotherapy, and chemotherapy. Recent studies on cancer genomic have revealed crucial insights into dynamic molecular subgroups within GBM, which govern distinct clinical response and sensitivity of each individual to therapy. In the present study, we analyzed genomic composition of primary GBMs between two ethnic groups [IRCR (Institute of Refractory Cancer Research), and TCGA (The Cancer Genome Atlats)] to explore genomic and molecular features that constitute malignant behavior of glioblastoma based on distinct ethnicity. We identified enrichments of MAPK and p53 pathways in IRCR patients, while aberrant activation of Receptor Tyrosine Kinases (RTKs) were predominant in TCGA cohort. We also discovered differential clinical prognosis between two groups and explored essential features that present such diversity.

MDSC subtypes and CD39 expression on CD8+ T cells predict the efficacy of anti-PD-1 immunotherapy in patients with advanced NSCLC

The major suppressive immune cells in tumor sites are myeloid derived suppressor cells (MDSCs), tumor‐associated macrophages (TAMs), and Treg cells, and the major roles of these suppressive immune cells include hindering T‐cell activities and supporting tumor progression and survival. In this study, we analyzed the pattern of circulating MDSC subtypes in patients with non‐small cell lung cancer (NSCLC) whether those suppressive immune cells hinder T‐cell activities leading to poor clinical outcomes. First, we verified PMN‐MDSCs, monocytic‐MDSCs (M‐MDSCs), and Treg cells increased according to the stages of NSCLC, and MDSCs effectively suppressed T‐cell activities and induced T‐cell exhaustion. The analysis of NSCLC patients treated with anti‐PD‐1 immunotherapy demonstrated that low PMN‐MDSCs, M‐MDSCs, and CD39⁺CD8⁺ T cells as an individual and all together were associated with longer progression free survival and overall survival, suggesting PMN‐MDSCs, M‐MDSCs, and CD39⁺CD8⁺ T cells frequencies in peripheral blood might be useful as potential predictive and prognostic biomarkers.

Integrated pharmaco-proteogenomics defines two subgroups in isocitrate dehydrogenase wild-type glioblastoma with prognostic and therapeutic opportunities

The prognostic and therapeutic relevance of molecular subtypes for the most aggressive isocitrate dehydrogenase 1/2 (IDH) wild-type glioblastoma (GBM) is currently limited due to high molecular heterogeneity of the tumors that impedes patient stratification. Here, we describe a distinct binary classification of IDH wild-type GBM tumors derived from a quantitative proteomic analysis of 39 IDH wild-type GBMs as well as IDH mutant and low-grade glioma controls. Specifically, GBM proteomic cluster 1 (GPC1) tumors exhibit Warburg-like features, neural stem-cell markers, immune checkpoint ligands, and a poor prognostic biomarker, FKBP prolyl isomerase 9 (FKBP9). Meanwhile, GPC2 tumors show elevated oxidative phosphorylation-related proteins, differentiated oligodendrocyte and astrocyte markers, and a favorable prognostic biomarker, phosphoglycerate dehydrogenase (PHGDH). Integrating these proteomic features with the pharmacological profiles of matched patient-derived cells (PDCs) reveals that the mTORC1/2 dual inhibitor AZD2014 is cytotoxic to the poor prognostic PDCs. Our analyses will guide GBM prognosis and precision treatment strategies.

The heterogeneity of IDH1/2 wild-type glioblastoma limits its prognosis and therapy. Here, the authors show a binary stratification, based on quantitative proteomic analysis of samples from patients with glioblastoma, with different prognosis and therapeutic vulnerabilities.

Multi-Habitat Radiomics Unravels Distinct Phenotypic Subtypes of Glioblastoma with Clinical and Genomic Significance

We aimed to evaluate the potential of radiomics as an imaging biomarker for glioblastoma (GBM) patients and explore the molecular rationale behind radiomics using a radio-genomics approach. A total of 144 primary GBM patients were included in this study (training cohort). Using multi-parametric MR images, radiomics features were extracted from multi-habitats of the tumor. We applied Cox-LASSO algorithm to build a survival prediction model, which we validated using an independent validation cohort. GBM patients were consensus clustered to reveal inherent phenotypic subtypes. GBM patients were successfully stratified by the radiomics risk score, a weighted sum of radiomics features, corroborating the potential of radiomics as a prognostic biomarker. Using consensus clustering, we identified three distinct subtypes which significantly differed in the prognosis ("heterogenous enhancing", "rim-enhancing necrotic", and "cystic" subtypes). Transcriptomic traits enriched in individual subtypes were in accordance with imaging phenotypes summarized by radiomics. For example, rim-enhancing necrotic subtype was well described by radiomics profiling (T2 autocorrelation and flat shape) and highlighted by the inflammatory genomic signatures, which well correlated to its phenotypic peculiarity (necrosis). This study showed that imaging subtypes derived from radiomics successfully recapitulated the genomic underpinnings of GBMs and thereby confirmed the feasibility of radiomics as an imaging biomarker for GBM patients with comprehensible biologic annotation.

Distinct genomic profile and specific targeted drug responses in adult cerebellar glioblastoma

Background

Despite extensive efforts on the genomic characterization of gliomas, very few studies have reported the genetic alterations of cerebellar glioblastoma (C-GBM), a rare and lethal disease. Here, we provide a systematic study of C-GBM to better understand its specific genomic features.

Methods

We collected a cohort of C-GBM patients and compared patient demographics and tumor pathologies with supratentorial glioblastoma (S-GBM). To uncover the molecular characteristics, we performed DNA and mRNA sequencing and DNA methylation arrays on 19, 6, and 4 C-GBM cases, respectively. Moreover, chemical drug screening was conducted to identify potential therapeutic options for C-GBMs.

Results

Despite differing anatomical origins of C-GBM and S-GBM, neither histological, cytological, nor patient demographics appeared significantly different between the 2 types. However, we observed striking differences in mutational patterns, including frequent alterations of ATRX, PDGFRA, NF1, and RAS and absence of EGFR alterations in C-GBM. These results show a distinct evolutionary path in C-GBM, suggesting specific therapeutic targeted options. Targeted-drug screening revealed that C-GBMs were more responsive to mitogen-activated protein kinase kinase (MEK) inhibitor and resistant to epidermal growth factor receptor inhibitors than S-GBMs. Also, differential expression analysis indicated that C-GBMs may have originated from oligodendrocyte progenitor cells, suggesting that different types of cells can undergo malignant transformation according to their location in brain. Master regulator analysis with differentially expressed genes between C-GBM and proneural S-GBM revealed NR4A1 as a potential therapeutic target.

Conclusions

Our results imply that unique gliomagenesis mechanisms occur in adult cerebellum and new treatment strategies are needed to provide greater therapeutic benefits for C-GBM patients.

Key Points

1. Distinct genomic profiles of 19 adult cerebellar GBMs were characterized. 2. MEK inhibitor was highly sensitive to cerebellar GBM compared with supratentorial GBM. 3. Master regulator analysis revealed NR4A1 as a potential therapeutic target in cerebellar GBM.

Identification of genomic and molecular traits that present therapeutic vulnerability to HGF-targeted therapy in glioblastoma

BACKGROUND

Cancer is a complex disease with profound genomic alterations and extensive heterogeneity. Recent studies on large-scale genomics have shed light on the impact of core oncogenic pathways, which are frequently dysregulated in a wide spectrum of cancer types. Aberrant activation of the hepatocyte growth factor (HGF) signaling axis has been associated with promoting various oncogenic programs during tumor initiation, progression, and treatment resistance. As a result, HGF-targeted therapy has emerged as an attractive therapeutic approach. However, recent clinical trials involving HGF-targeted therapies have demonstrated rather disappointing results. Thus, an alternative, in-depth assessment of new patient stratification is necessary to shift the current clinical course.

METHODS

To address such challenges, we have evaluated the therapeutic efficacy of YYB-101, an HGF-neutralizing antibody, in a series of primary glioblastoma stem cells (GSCs) both in vitro and in vivo. Furthermore, we performed genome and transcriptome analysis to determine genetic and molecular traits that exhibit therapeutic susceptibility to HGF-mediated therapy.

RESULTS

We have identified several differentially expressed genes, including MET, KDR, and SOX3, which are associated with tumor invasiveness, malignancy, and unfavorable prognosis in glioblastoma patients. We also demonstrated the HGF-MET signaling axis as a key molecular determinant in GSC invasion, and we discovered that a significant association in HGF expression existed between mesenchymal phenotype and immune cell recruitment.

CONCLUSIONS

Upregulation of MET and mesenchymal cellular state are essential in generating HGF-mediated therapeutic responses. Our results provide an important framework for evaluating HGF-targeted therapy in future clinical settings.

Sphere-Forming Culture for Expanding Genetically Distinct Patient-Derived Glioma Stem Cells by Cellular Growth Rate Screening

Diffusely infiltrating gliomas (DIGs) are difficult to completely resect and are associated with a high rate of tumor relapse and progression from low- to high-grade glioma. In particular, optimized short-term culture-enriching patient-derived glioma stem cells (GSCs) are essential for customizing the therapeutic strategy based on clinically feasible in vitro drug screening for a wide range of DIGs, owing to the high inter-tumoral heterogeneity. Herein, we constructed a novel high-throughput culture condition screening platform called ‘GFSCAN’, which evaluated the cellular growth rates of GSCs for each DIG sample in 132 serum-free combinations, using 13 previously reported growth factors closely associated with glioma aggressiveness. In total, 72 patient-derived GSCs with available genomic profiles were tested in GFSCAN to explore the association between cellular growth rates in specific growth factor combinations and genomic/molecular backgrounds, including isocitrate dehydrogenase 1 (IDH1) mutation, chromosome arm 1p and 19q co-deletion, ATRX chromatin remodeler alteration, and transcriptional subtype. GSCs were clustered according to the dependency on epidermal growth factor and basic fibroblast growth factor (E&F), and isocitrate dehydrogenase 1 (IDH1) wild-type GSCs showed higher E&F dependencies than IDH1 mutant GSCs. More importantly, we elucidated optimal combinations for IDH1 mutant glioblastoma and lower grade glioma GSCs with low dependencies on E&F, which could be an aid in clinical decision-making for these DIGs. Thus, we demonstrated the utility of GFSCAN in personalizing in vitro cultivation to nominate personalized therapeutic options, in a clinically relevant time frame, for individual DIG patients, where standard clinical options have been exhausted.

Comprehensive pharmacogenomic characterization of gastric cancer

BACKGROUND

Gastric cancer is among the most lethal human malignancies. Previous studies have identified molecular aberrations that constitute dynamic biological networks and genomic complexities of gastric tumors. However, the clinical translation of molecular-guided targeted therapy is hampered by challenges. Notably, solid tumors often harbor multiple genetic alterations, complicating the development of effective treatments.

METHODS

To address such challenges, we established a comprehensive dataset of molecularly annotated patient derivatives coupled with pharmacological profiles for 60 targeted agents to explore dynamic pharmacogenomic interactions in gastric cancers.

RESULTS

We identified lineage-specific drug sensitivities based on histopathological and molecular subclassification, including substantial sensitivities toward VEGFR and EGFR inhibition therapies in diffuse- and signet ring-type gastric tumors, respectively. We identified potential therapeutic opportunities for WNT pathway inhibitors in ALK-mutant tumors, a significant association between PIK3CA-E542K mutation and AZD5363 response, and transcriptome expression of RNF11 as a potential predictor of response to gefitinib.

CONCLUSIONS

Collectively, our results demonstrate the feasibility of drug screening combined with tumor molecular characterization to facilitate personalized therapeutic regimens for gastric tumors.

Tumor edge-to-core transition promotes malignancy in primary-to-recurrent glioblastoma progression in a PLAGL1/CD109-mediated mechanism

BACKGROUND

Glioblastoma remains highly lethal due to its inevitable recurrence. Most of this recurrence is found locally, indicating that postsurgical tumor-initiating cells (TICs) accumulate at the tumor edge. These edge-TICs then generate local recurrence harboring new core lesions. Here, we investigated the clinical significance of the edge-to-core (E-to-C) signature generating glioblastoma recurrence and sought to identify its central mediators.

METHODS

First, we examined the association of E-to-C-related expression changes to patient outcome in matched primary and recurrent samples (n = 37). Specifically, we tested whether the combined decrease of the edge-TIC marker PROM1 (CD133) with the increase of the core-TIC marker CD109, representing E-to-C transition during the primary-to-recurrence progression, indicates poorer patient outcome. We then investigated the specific molecular mediators that trigger tumor recurrence driven by the E-to-C progression. Subsequently, the functional and translational significance of the identified molecule was validated with our patient-derived edge-TIC models in vitro and in vivo.

RESULTS

Patients exhibiting the CD133low/CD109high signature upon recurrence representing E-to-C transition displayed a strong association with poorer progression-free survival and overall survival among all tested patients. Differential gene expression identified that PLAGL1 was tightly correlated with the core TIC marker CD109 and was linked to shorter patient survival. Experimentally, forced PLAGL1 overexpression enhanced, while its knockdown reduced, glioblastoma edge-derived tumor growth in vivo and subsequent mouse survival, suggesting its essential role in the E-to-C-mediated glioblastoma progression.

CONCLUSIONS

E-to-C axis represents an ongoing lethal process in primary glioblastoma contributing to its recurrence, partly in a PLAGL1/CD109-mediated mechanism.

Pharmacogenomic analysis of patient-derived tumor cells in gynecologic cancers

Background

Gynecologic malignancy is one of the leading causes of mortality in female adults worldwide. Comprehensive genomic analysis has revealed a list of molecular aberrations that are essential to tumorigenesis, progression, and metastasis of gynecologic tumors. However, targeting such alterations has frequently led to treatment failures due to underlying genomic complexity and simultaneous activation of various tumor cell survival pathway molecules. A compilation of molecular characterization of tumors with pharmacological drug response is the next step toward clinical application of patient-tailored treatment regimens.

Results

Toward this goal, we establish a library of 139 gynecologic tumors including epithelial ovarian cancers (EOCs), cervical, endometrial tumors, and uterine sarcomas that are genomically and/or pharmacologically annotated and explore dynamic pharmacogenomic associations against 37 molecularly targeted drugs. We discover lineage-specific drug sensitivities based on subcategorization of gynecologic tumors and identify TP53 mutation as a molecular determinant that elicits therapeutic response to poly (ADP-Ribose) polymerase (PARP) inhibitor. We further identify transcriptome expression of inhibitor of DNA biding 2 (ID2) as a potential predictive biomarker for treatment response to olaparib.

Conclusions

Together, our results demonstrate the potential utility of rapid drug screening combined with genomic profiling for precision treatment of gynecologic cancers.

Postpartum women’s experience of abuse in childhood, postnatal depression, and thoughts of self-harm

Background

Postnatal depression threatens the health of both mothers and babies. To improve maternal and child health in Seoul, South Korea, a nurse home visitation program for pregnant women and new mothers and babies has been implemented since 2013.

Methods

Cross-sectional data collected from 9,124 mothers while they were visiting a public health center for prenatal services or a nurse was visiting their home within 6 weeks after birth between 2014 and 2018 were analyzed. Mothers were asked whether they had experienced physical, emotional, or sexual abuse in their childhood. Postnatal depression and thoughts of self-harm were measured using the Edinburgh Postnatal Depression Scale (EPDS). Postnatal depression was defined as a total EPDS score of 13 or higher; thoughts of self-harm were defined as a response of “yes, quite often,” “sometimes,” or “hardly ever” to the corresponding item, excluding the response of “never".

Results

Overall, 3.2% of mothers had experienced child abuse; 8.1% experienced postnatal depression and 5.4% reported thoughts of self-harm. Postnatal depression was more common in mothers who had experienced child abuse than among those who had not (24.2% vs. 7.6%). A similar pattern was found for thoughts of self-harm (21.1% vs. 4.9%, respectively). When controlling for mothers’ age, economic status, history of receiving treatment for mental health problems, and other factors, having experienced child abuse was associated with a 2.73-fold increase in the odds of postnatal depression (odds ratio, 2.02-3.70) and a 3.58-fold increase in the odds of thoughts of self-harm (odds ratio, 2.58-4.96).

Conclusions

Mothers should be screened for having experienced child abuse when providing public health perinatal care to improve mothers’ mental health and parenting practices and to promote their children’s growth and development.

Key messages

Child abuse may have a lifelong negative effect on victims, and the effect extends to the next generation’s health and development. Public health policy and interventions to prevent child abuse are needed to tackle health inequality beginning in early childhood.

P313ADGRL2 is an essential surface molecule for cardiac lineage specification and heart development

Background

Specific surface markers that enable monitoring of cell subsets would be valuable for establishing the conditions under which pluripotent stem cells (PSCs) differentiate into cardiac progenitor cells (CPCs) and cardiomyocytes (CMCs).

Methods and results

To verify whether a specific marker is expressed during heart development, we assessed its expression using the CLARITY technique. After immersion in a solution with a refractive index matching that of the CLARITY hybrid, the mouse embryo became transparent. After immunostaining the cleared embryo sample, Adgrl2 was exclusively observed in cardiac cells expressing α-SA at embryonic day E9.5 and E10.5. Our clarified 3D images and movies show that four chambers of the heart are fully developed at E10.5 but not at E9.5. At E9.5, Adgrl2 is observed at the ventricle and atrium, while Adgrl2 is present in all chambers of the heart at E10.5. Next, we performed LacZ (β-Gal) staining in heterozygous Adgrl2 KO embryos to evaluate Adgrl2 expression. As a result, LacZ staining showed that Adgrl2 was predominantly expressed in the heart during the embryonic developmental stage. Adgrl2 knockout in mice was embryonically lethal because of severe heart, but not vascular, defects. To examine the use of Adgrl2 as a bona fide CPC marker during heart development, we tracked Adgrl2 expression during early embryonic development. The heart of Adgrl2−/− embryos at E10.5 exhibited occlusion of the RV, and the expression levels of Gata4 and Nkx2.5 were not as high as those in wild-type and Adgrl2+/− embryos. Interestingly, the heart of Adgrl2−/− embryos, unlike those of wild-type and Adgrl2+/− embryos between E13.5 and E15.5 had a single ventricle revealing a ventricular septal defect. The specific expression pattern of Adgrl2 in PSC-derived cardiac lineage cells as well as in embryonic heart, adult mice, and human heart tissues.

Conclusion

We demonstrate that Adgrl2 plays a pivotal and functional role across all strata of the cardiomyogenic lineage, as early as the precursor stage of heart development. These findings shed light on heart development and regeneration.

Acknowledgement/Funding

Grants from “Strategic Center of Cell and Bio Therapy” (grant number: HI17C2085) and “Korea Research-Driven Hospital” (HI14C1277)

P3479Sequential stimulation and inhibition of lysophosphatidic acid receptor 4 are critical for cardiac differentiation and repair

Background

The clinical application of cell therapy to repair the damaged heart needs to understand the precise differentiation process of stem cells and the characteristics of cardiac progenitor cells.

Purpose

We examined the cardiac-specific markers that expressed on the cell surface and determined their functional significance during cardiac differentiation.

Methods and results

We screened cell-surface expressing proteins on cardiac progenitor cells at differentiation day 3 compared to undifferentiated pluripotent stem cells (PSCs). Among candidates, we identified lysophosphatidic acid receptor 4 (LPAR4) that is a G protein-coupled receptor. During in vitro differentiation of mouse PSCs toward cardiac cells, LPAR4 expression peaked for 3–5 days and then and declined immediately. Also in vivo, LPAR4 was specifically expressed in the early stage of heart development in embryos and disappeared completely in adults, suggesting that stimulatory signal of LPAR4 at an early stage should be shut off for further progression of differentiation. We next have identified the LPAR4 downstream signaling molecule, p38MAPK, by comparing PSCs and LPAR4 knockdown PSCs. In both mouse and human PSCs, ODP (LPAR4 specific agonist) followed by p38MAPK blocker (SB203580) treatment significantly increased cardiac differentiation efficiency. Furthermore, we investigated whether LPAR4 is the maker for adult cardiac progenitor cells. We found that LPAR4-positive cells were rarely present in normal adult mouse hearts, but LPAR4-positive cells were increased when the heart was damaged. LPAR4-positive cells from adult hearts differentiated into cardiomyocytes. After myocardial infarction (MI), the sequential stimulation and inhibition of LPAR4 with ODP and p38MAPK blocker resulted in the reduction of infarct size and improvement of left ventricular dysfunction.

Conclusion

We demonstrated that LPAR4 is a cardiac progenitor-specific marker and its functional significance during cardiac differentiation and regeneration. Our findings provide a new insight in cell-free cardiac repair by the modulation of progenitor-specific downstream signaling.

Acknowledgement/Funding

Grants from “Strategic Center of Cell and Bio Therapy” (grant number: HI17C2085) and “Korea Research-Driven Hospital” (HI14C1277)

Clinical Targeted Next-Generation sequencing Panels for Detection of Somatic Variants in Gliomas

PURPOSE

Targeted next-generation sequencing (NGS) panels for solid tumors have been useful in clinical framework for accurate tumor diagnosis and identifying essential molecular aberrations. However, most cancer panels have been designed to address a wide spectrum of pan-cancer models, lacking integral prognostic markers that are highly specific to gliomas.

Materials and Methods

To address such challenges, we have developed a glioma-specific NGS panel, termed "GliomaSCAN," that is capable of capturing single nucleotide variations and insertion/deletion, copy number variation, and selected promoter mutations and structural variations that cover a subset of intron regions in 232 essential glioma-associated genes. We confirmed clinical concordance rate using pairwise comparison of the identified variants from whole exome sequencing (WES), immunohistochemical analysis, and fluorescence in situ hybridization.

RESULTS

Our panel demonstrated high sensitivity in detecting potential genomic variants that were present in the standard materials. To ensure the accuracy of our targeted sequencing panel, we compared our targeted panel to WES. The comparison results demonstrated a high correlation. Furthermore, we evaluated clinical utility of our panel in 46 glioma patients to assess the detection capacity of potential actionable mutations. Thirty-two patients harbored at least one recurrent somatic mutation in clinically actionable gene.

CONCLUSION

We have established a glioma-specific cancer panel. GliomaSCAN highly excelled in capturing somatic variations in terms of both sensitivity and specificity and provided potential clinical implication in facilitating genome-based clinical trials. Our results could provide conceptual advance towards improving the response of genomically guided molecularly targeted therapy in glioma patients.

PIP4K2A as a negative regulator of PI3K in PTEN-deficient glioblastoma

Glioblastoma (GBM) is the most malignant brain tumor with profound genomic alterations. Tumor suppressor genes regulate multiple signaling networks that restrict cellular proliferation and present barriers to malignant transformation. While bona fide tumor suppressors such as PTEN and TP53 often undergo inactivation due to mutations, there are several genes for which genomic deletion is the primary route for tumor progression. To functionally identify putative tumor suppressors in GBM, we employed in vivo RNAi screening using patient-derived xenograft models. Here, we identified PIP4K2A, whose functional role and clinical relevance remain unexplored in GBM. We discovered that PIP4K2A negatively regulates phosphoinositide 3-kinase (PI3K) signaling via p85/p110 component degradation in PTEN-deficient GBMs and specifically targets p85 for proteasome-mediated degradation. Overexpression of PIP4K2A suppressed cellular and clonogenic growth in vitro and impeded tumor growth in vivo. Our results unravel a novel tumor-suppressive role of PIP4K2A for the first time and support the feasibility of combining oncogenomics with in vivo RNAi screen.

Abstract A138: CD39 increase on cytotoxic T-cell induced by myeloid-derived suppressor cell correlated with poor prognosis in patients with non-small cell lung cancer

Background: The factors in tumor microenvironment hinder T-cell activities against tumor cells. The major immunosuppressive cells in tumor sites are myeloid-derived suppressor cell (MDSC), tumor-associated macrophage (TAM), and regulatory T (Treg) cell, and the effector molecules released by those immunosuppressive cells also regulate T-cell activities. Therefore, in this study we examined the pattern of immunosuppressive cells in patients with non-small cell lung cancer. Then, we tested T-cell activities to verify whether the suppressive immune cell populations can influence T-cell activity by monitoring T-cell exhaustion markers. Since CD39 and CD73 expression on cytotoxic T-cell are known to be T-cell exhaustion markers, we analyzed CD39 and CD73 on CD8+ T-cells. Method: Baseline and one week after anti-PD-1 immunotherapy (pembrolizumab and nivolumab) blood samples (n=81) were collected (stage III and IV). For the correlation of suppressive immune cells with disease progression, baseline blood samples from the patients (n=59, stage I~IV) and healthy donors (n=21) were collected. Granulocytic-MDSC, Monocytic-MDSC, TAM, Treg, and CD39+ and CD73+ cytotoxic T-cell population from patients’ PBMC (n=81 and n=59) were analyzed by FACS Verse. For the suppressive assay, isolated T-cells were activated with anti-CD3 and anti-CD28 and then MDSC was co-cultured with T-cells for a week followed by Ki-67, CD39 and CD73 analysis by FACS Verse. Results: G-MDSC (p-value=0.0023), M-MDSC (p-value=0.0032), TAM ((p&lt;0.001), and Treg (p&lt;0.001) population were higher in advanced non-small cell lung cancer patients (stage III&IV) compared with stage I and II patients or healthy donors. MDSC isolated from patient’s blood was co-cultured with activated T-cells from the same patient. After one week, T-cell activity was inhibited compared with T-cell alone (p &lt; 0.001, E:T = 5:1, 10:1) confirming suppressive activity of MDSC against T-cells. CD39+CD8+ T-cells were also increased when co-cultured with MDSC. Low MDSC (p-value=0.02) and CD39+CD8+ T-cell population (p-value=0.043) in pre and post-anti-PD-1 immunotherapy and the population decreased group showed better overall survival compared to high and increased MDSC and CD39+CD8+ T-cell population group of the patients. Conclusion: G-MDSC and M-MDSC population increased as disease progressed and MDSC effectively suppressed T-cell activities and induced T-cell exhaustion. TAM and Treg population also increased in advanced non-small cell lung cancer patients. Increased MDSC and CD39+CD8+ T-cells correlated with poor prognosis in patients treated with anti-PD-1 immunotherapy. Therefore, high MDSC and increased CD39 expression on cytotoxic T-cell can be used as a prognostic biomarker for anti-PD-1 immunotherapy in patients with non-small cell lung cancer.

Citation Format: Jiae Koh, Kyung Young Lee, Boram Kim, Mi Soon Kim, Hee Jin Cho, Jong-Mu Sun, Jin Seok Ahn, Keunchil Park, Myung-Ju Ahn. CD39 increase on cytotoxic T-cell induced by myeloid-derived suppressor cell correlated with poor prognosis in patients with non-small cell lung cancer [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A138.

Predictive value of a fragmented QRS complex in diagnosing patients with myocardial ischemia

Background

A fragmented QRS complex (fQRS) is caused by conduction abnormalities of the ventricle secondary to myocardial ischemia and/or scar in patients with myocardial infarction. However, the implications of the fQRS in the development of coronary artery disease with myocardial ischemia in those without a scar remain unknown.

Methods

We studied electrocardiograms (ECGs) obtained from 150 patients (60.5 ± 8.5 years, 102 men) with myocardial ischemia, which was confirmed by performing both, a nuclear exercise stress test and coronary angiography. We also studied ECGs obtained from 601 patients (58.5 ± 10.0 years, 315 men) who showed a negative nuclear exercise stress test (control group). Patients in whom the nuclear exercise stress test showed a myocardial scar were excluded.

Results

An fQRS was more commonly observed in patients with myocardial ischemia (n = 48, 32.0%) than in the control group (n = 133, 22.1%) (P = 0.011). The sensitivity, specificity, positive, and negative predictive values of fQRS in diagnosing myocardial ischemia were 32.0, 77.9, 26.5, and 82.1%, respectively. The fQRS (odds ratio 1.580, 95% confidence interval 1.020‐2.446, P = 0.040) was an independent predictor of myocardial ischemia after adjusting for age, sex, current smoking habits, ST‐T changes on ECG, as well as histories of hypertension, diabetes, and dyslipidemia. Moreover, the fQRS showed an incremental prognostic value over conventional risk factors (χ² = 5, P = 0.032) and over a combination of conventional factors and ST‐T changes (χ² = 9, P = 0.014).

Conclusions

The fQRS is a moderately sensitive and independent predictor of myocardial ischemia.

Potent effect of the MDM2 inhibitor AMG232 on suppression of glioblastoma stem cells

Testing new ways to identify untapped opportunities for glioblastoma therapies remains highly significant. Amplification and overexpression of MDM2 gene is frequent in glioblastoma and disrupting the MDM2-p53 interaction is a promising strategy to treat the cancer. RG7112 is the first-in class inhibitor and recently discovered AMG232 is the most potent MDM2 inhibitor known to date. Here, we compared the effects of these two clinical MDM2 inhibitors in six glioblastoma cell lines and ten patient-derived glioblastoma stem cells. Targeted sequencing of the TP53, MDM2 genes and whole transcriptome analysis were conducted to verify genetic status associated with sensitivity and resistance to the drugs. Although TP53 wild-type glioblastoma cell lines are similarly sensitive to AMG232 and RG7112, we found that four TP53 wild-type out of ten patient-derived glioblastoma cells are much more sensitive to AMG232 than RG7112 (average IC₅₀ of 76 nM vs. 720 nM). Among these, 464T stem cells containing MDM2 gene amplification were most sensitive to AMG232 with IC₅₀ of 5.3 nM. Moreover, AMG232 exhibited higher selectivity against p53 wild-type cells over p53 mutant stem cells compared to RG7112 (average selectivity of 512-fold vs. 16.5-fold). Importantly, we also found that AMG232 is highly efficacious in three-dimensional (3D) tumor spheroids growth and effectively inhibits the stemness-related factors, Nestin and ZEB1. Our data provide new evidence that glioblastoma stem cells have high susceptibility to AMG232 suggesting the potential clinical implications of MDM2 inhibition for glioblastoma treatment. These will facilitate additional preclinical and clinical studies evaluating MDM2 inhibitors in glioblastoma and direct further efforts towards developing better MDM2-targeted therapeutics.

Scorpionate Catalysts for Coupling CO2 and Epoxides to Cyclic Carbonates: A Rational Design Approach for Organocatalysts

Novel scorpionate-type organocatalysts capable of effectively coupling carbon dioxide and epoxides under mild conditions to afford cyclic propylene carbonates were developed. On the basis of a combined experimental and computational study, a precise mechanistic proposal was developed and rational optimization strategies were identified. The epoxide ring-opening, which requires an iodide as a nucleophile, was enhanced by utilizing an immonium functionality that can form an ion pair with iodide, making the ring-opening process intramolecular. The CO₂ activation and cyclic carbonate formation were catalyzed by the concerted action of two hydrogen bonds originating from two phenolic groups placed at the claw positions of the scorpionate scaffold. Electronic tuning of the hydrogen bond donors allowed to identify a new catalyst that can deliver >90% yield for a variety of epoxide substrates within 7 h at room temperature under a CO₂ pressure of only 10 bar, and is highly recyclable.

Identification of transcriptome signature for predicting clinical response to bevacizumab in recurrent glioblastoma

Glioblastomas are among the most fatal brain tumors. Although no effective treatment option is available for recurrent glioblastomas (GBMs), a subset of patients evidently derived clinical benefit from bevacizumab, a monoclonal antibody against vascular endothelial growth factor. We retrospectively reviewed patients with recurrent GBM who received bevacizumab to identify biomarkers for predicting clinical response to bevacizumab. Following defined criteria, the patients were categorized into two clinical response groups, and their genetic and transcriptomic results were compared. Angiogenesis‐related gene sets were upregulated in both responders and nonresponders, whereas genes for each corresponding angiogenesis pathway were distinct from one another. Two gene sets were made, namely, the nonresponder angiogenesis gene set (NAG) and responder angiogenesis gene set (RAG), and then implemented in independent GBM cohort to validate our dataset. A similar association between the corresponding gene set and survival was observed. In NAG, COL4A2 was associated with a poor clinical outcome in bevacizumab‐treated patients. This study demonstrates that angiogenesis‐associated gene sets are composed of distinct subsets with diverse biological roles and they represent different clinical responses to anti‐angiogenic therapy. Enrichment of a distinct angiogenesis pathway may serve as a biomarker to predict patients who will derive a clinical benefit from bevacizumab.