A gB nanoparticle vaccine elicits a protective neutralizing antibody response against EBV.

Epstein-Barr virus (EBV) is a global public health concern, as it is known to cause multiple diseases while also being etiologically associated with a wide range of epithelial and lymphoid malignancies. Currently, there is no available prophylactic vaccine against EBV. gB is the EBV fusion protein that mediates viral membrane fusion and participates in host recognition, making it critical for EBV infection in both B cells and epithelial cells. Here, we present a gB nanoparticle, gB-I53-50 NP, that displays multiple copies of gB. Compared with the gB trimer, gB-I53-50 NP shows improved structural integrity and stability, as well as enhanced immunogenicity in mice and non-human primate (NHP) preclinical models. Immunization and passive transfer demonstrate a robust and durable protective antibody response that protects humanized mice against lethal EBV challenge. This vaccine candidate demonstrates significant potential in preventing EBV infection, providing a possible platform for developing prophylactic vaccines for EBV.

Genomic Profiling of Radiation-Induced Sarcomas Reveals the Immunologic Characteristics and Its Response to Immune Checkpoint Blockade.

PURPOSE: Radiation-induced sarcomas (RIS) have a poor prognosis and lack effective treatments. Its genome and tumor microenvironment are not well characterized and need further exploration. EXPERIMENTAL DESIGN: Here, we performed whole-exome sequencing (WES) and mRNA sequencing (mRNA-seq) on patients with RIS and primary sarcomas (WES samples 46 vs. 48, mRNA-seq samples 16 vs. 8, mainly in head and neck), investigated the antitumor effect of programmed cell death protein 1 (PD-1) blockade in RIS patient-derived xenograft models, and analyzed clinical data of patients with RIS treated with chemotherapy alone or combined with an anti-PD-1 antibody. RESULTS: Compared with primary sarcomas, RIS manifested different patterns of copy-number variations, a significantly higher number of predicted strong MHC-binding neoantigens, and significantly increased immune cell infiltration. Clinical data showed that the combinatorial use of chemotherapy and PD-1 blockade achieved a higher objective response rate (36.67% vs. 8.00%; P = 0.003), longer overall survival (31.9 months vs. 14.8 months; P = 0.014), and longer progression-free survival (4.7 months vs. 9.5 months; P = 0.032) in patients with RIS compared with single chemotherapy. CONCLUSIONS: Elevated genomic instability and higher immune cell infiltrations were found in RIS than in primary sarcomas. Moreover, higher efficacy of chemotherapy plus PD-1 blockade was observed in animal experiments and clinical practice. This evidence indicated the promising application of immune checkpoint inhibitors in the treatment of RIS.

Development and validation of an RNA sequencing panel for gene fusions in soft tissue sarcoma.

Gene fusions are one of the most common genomic alterations in soft tissue sarcomas (STS), which contain more than 70 subtypes. In this study, a custom-designed RNA sequencing panel including 67 genes was developed and validated to identify gene fusions in STS. In total, 92 STS samples were analyzed using the RNA panel and 95.7% (88/92) successfully passed all the quality control parameters. Fusion transcripts were detected in 60.2% (53/88) of samples, including three novel fusions (MEG3-PLAG1, SH3BP1-NTRK1, and RPSAP52-HMGA2). The panel demonstrated excellent analytic accuracy, with 93.9% sensitivity and 100% specificity. The intra-assay, inter-assay, and personnel consistencies were all 100.0% in four samples and three replicates. In addition, different variants of ESWR1-FLI, COL1A1-PDGFB, NAB2-STAT6, and SS18-SSX were also identified in the corresponding subtypes of STS. In combination with histological and molecular diagnosis, 14.8% (13/88) patients finally changed preliminary histology-based classification. Collectively, this RNA panel developed in our study shows excellent performance on RNA from formalin-fixed, paraffin-embedded samples and can complement DNA-based assay, thereby facilitating precise diagnosis and novel fusion detection.

Corrigendum: The Paradoxical Role of Cellular Senescence in Cancer.

[This corrects the article DOI: 10.3389/fcell.2021.722205.].

Trends in clinical development of pediatric cancer for PD-1 and PD-L1 inhibitors: an analysis of ClinicalTrials.gov.

Compared with cytotoxic chemotherapy, radiotherapy, and surgery, positive findings have been acquired through the approach of blocking the programmed cell death protein 1 (PD-1) pathway with antibodies that exert inhibitory effects on PD-1 or cell death protein ligand 1 (PD-L1). Results from clinical trials showed great potential in adult patients with cancers, such as melanoma, non-small cell carcinoma, and nasopharyngeal carcinoma. However, studies of checkpoint inhibitors specifically targeting PD-1/PD-L1 in pediatric patients are limited. We evaluated ongoing clinical trials using PD-1 or PD-L1 inhibitors alone or in combination with other therapies to treat pediatric cancer. The proportion of PD-1/PD-L1 combination clinical trials has increased since 2018; the three most common trials over the past 2 years used CTLA-4 monoclonal antibodies, chemotherapy, and therapies that target the vascular endothelial growth factor axis. This commentary aimed to provide trends and specific insights into methods for conducting clinical trials of immunotherapy in the pediatric population.

The Paradoxical Role of Cellular Senescence in Cancer.

Cellular senescence occurs in proliferating cells as a consequence of various triggers including telomere shortening, DNA damage, and inappropriate expression of oncogenes. The senescent state is accompanied by failure to reenter the cell cycle under mitotic stimulation, resistance to cell death and enhanced secretory phenotype. A growing number of studies have convincingly demonstrated a paradoxical role for spontaneous senescence and therapy-induced senescence (TIS), that senescence may involve both cancer prevention and cancer aggressiveness. Cellular senescence was initially described as a physiological suppressor mechanism of tumor cells, because cancer development requires cell proliferation. However, there is growing evidence that senescent cells may contribute to oncogenesis, partly in a senescence-associated secretory phenotype (SASP)-dependent manner. On the one hand, SASP prevents cell division and promotes immune clearance of damaged cells, thereby avoiding tumor development. On the other hand, SASP contributes to tumor progression and relapse through creating an immunosuppressive environment. In this review, we performed a review to summarize both bright and dark sides of senescence in cancer, and the strategies to handle senescence in cancer therapy were also discussed.

Frequent amplification of HDAC genes and efficacy of HDAC inhibitor chidamide and PD-1 blockade combination in soft tissue sarcoma.

BACKGROUND: The advent of immune checkpoint therapy has been a tremendous advance in cancer treatment. However, the responses are still insufficient in patients with soft tissue sarcoma (STS). We aimed to identify rational combinations to increase the response to immune checkpoint therapy and improve survival. METHODS: Whole-exome sequencing (WES) was performed in 11 patients with liposarcoma. Somatic copy number alterations (SCNAs) were analyzed at the gene level to identify obvious amplification patterns in drug-target genes. The expression and prognostic value of class I histone deacetylases (HDACs) was evaluated in 49 patients with sarcoma in our center and confirmed in 263 sarcoma samples from The Tumor Cancer Genome Atlas (TCGA) database. Q-PCR, flow cytometry and RNA-seq were performed to determine the correlations between class I HDACs, chidamide and PD-L1 in vitro and in vivo. The efficacy of combining chidamide with PD-1 blockade was explored in an immunocompetent murine model and a small cohort of patients with advanced sarcoma. Western blot, ChIP assay and dual luciferase assessment were applied in the mechanistic study. RESULTS: The HDAC gene family was frequently amplified in STS. SCNAs in the HDAC gene family were extensively amplified in 8 of 11 (73%) patients with liposarcoma, based on a drug-target gene set, and we verified amplification in 76.65% (197/257) of cases by analyzing TCGA sarcoma cohort. Class I HDAC expression is associated with a poor prognosis for patients with STS, and its inhibition is responsible for promoting apoptosis and upregulating of programmed cell death ligand 1 (PD-L1). The HDAC class I inhibitor chidamide significantly increases PD-L1 expression, increased the infiltration of CD8+ T cells and reduced the number of MDSCs in the tumor microenvironment. The combination of chidamide with an anti-PD-1 antibody significantly promotes tumor regression and improves survival in a murine model. Moreover, chidamide combined with the anti-PD-1 antibody toripalimab is effective in patients with advanced and metastatic sarcoma, and the side effects are tolerable. Mechanistically, chidamide increases histone acetylation at the PD-L1 gene through the activation of the transcriptional factor STAT1. CONCLUSIONS: The combination of chidamide and anti-programmed cell death 1 (PD-1) therapy represents a potentially important strategy for STS.

Multi-omics analysis of copy number variations of RNA regulatory genes in soft tissue sarcoma.

AIMS: RNA regulatory genes were closely associated with tumorigenesis and prognosis in multiple tumors. Copy number variation (CNV) is a frequent characteristic in soft tissue sarcomas (STS). However, little is known regarding their possible roles in STS. MAIN METHODS: RNA sequence profiles and CNV data of 255 STS patients were downloaded from the Cancer Genome Atlas (TCGA). The correlation analysis involved CNVs of RNA regulatory genes, patient survival, immune infiltration, and DNA methylation. Drug sensitivity (IC50) was analyzed and validated by MTT assays in STS cell lines. KEY FINDINGS: CNV events were frequently observed in all kinds (m6A, m5C, ac4C, m1A, m3C, m6Am, m7G, and Ψ) of RNA regulatory genes. Diploid copy number (CN) of METTL4 was associated with better overall survival (OS) in STS and the subtypes (leiomyosarcoma, LMS; dedifferentiated liposarcoma, DDLPS). In STS and LMS, diploid CN of METTL4 was significantly associated with higher infiltration fraction of resting mast cells. In STS and DDLPS, diploid CN of METTL4 possessed lower methylation level in CpG site of cg12105018, which represented better OS. Besides, sensitive drugs for STS cell lines were analyzed according to lower IC50 for the loss CN of METTL4. Temozolomide and Olaparib were identified. Further validation by MTT assays demonstrated that GCT was the most sensitive cell line to both Temozolomide and Olaparib. SIGNIFICANCE: CNV of METTL4 could be a prognostic biomarker for STS by potentially influencing mast cell infiltration and DNA methylation. Besides, STS with loss CN of METTL4 would be sensitive to Temozolomide and Olaparib.

Time to Local Recurrence as a Predictor of Survival in Patients With Soft Tissue Sarcoma of the Extremity and Abdominothoracic Wall.

OBJECTIVE: The purpose of this retrospective study was to identify the prognostic significance of time to local recurrence (TLR) with regard to overall survival (OS) and survival after local recurrence (SAR) in patients with soft tissue sarcoma (STS) of the extremity and abdominothoracic wall. METHODS: We identified 477 patients who underwent R0 resection for localized STS of the extremity and abdominothoracic wall, from January 1995 to December 2016, of whom 190 patients developed local recurrence as their first recurrent event. Based on TLR, patients were divided into two groups: early local recurrence (ELR, <12 months) and late local recurrence (LLR, ≥12 months). The Kaplan-Meier method and Cox regression analysis were used to estimate the OS and SAR, and to identify factors associated with patient outcomes. RESULTS: The median follow-up time for the entire cohort was 118.4 months, and was 118.5 months for the 190 patients who developed local recurrence. Deep tumor location (HR 1.73, 95% CI 1.27-2.37, P = 0.001) and tumor grade ≥2 (G2 vs. G1: HR 1.75, 95% CI 1.21-2.53, G3 vs. G1: HR 2.57, 95% CI 1.66-3.98, P < 0.001) were associated with a higher rate of local recurrence. There were 99 patients in the ELR group and 91 in the LLR group, with a median TLR of 10.8 months for the entire cohort. Patients from the ELR group had a shorter OS and a lower 5-year OS rate than the LLR group. Univariate and multivariate analyses demonstrated TLR as an independent prognostic factor for SAR and OS, in addition to tumor grade. Also, surgical treatment and absence of metastasis after local recurrence were associated with longer SAR. CONCLUSIONS: In patients with STS of the extremity and abdominothoracic wall, ELR after R0 resection indicated a worse prognosis than those with LLR, and TLR can be considered an independent prognostic factor for OS and SAR. Furthermore, local recurrence was significantly influenced by the depth and the histopathological grading of the primary tumor, and reoperation after local recurrence could improve survival, which means salvage surgery may still be the preferred treatment when there are surgical indications after recurrence.

The prognostic role of the preoperative systemic immune-inflammation index and high-sensitivity modified Glasgow prognostic score in patients after radical operation for soft tissue sarcoma.

INTRODUCTION: The prognostic values of nutritional and immune-inflammatory indicators in non-metastatic soft tissue sarcoma (STS) patients are not clear. We investigated the utility of systemic immune-inflammation index (SII) and the high-sensitivity modified Glasgow prognostic score (Hs-mGPS) in the prediction of STS patient's prognosis. MATERIALS AND METHODS: Patients admitted between January 2000 and December 2016, who underwent R0 resection for STS at SYSUCC were carefully retrospectively reviewed, and 454 patients were enrolled. The laboratory data and clinical data were collected from the patient's record. ROC analysis is used to determine the optimal cutoff value. Survival curves were analysed by Kaplan-Meier method. Cox proportional hazard model was used to find out prognostic variables. RESULTS: Increased SII and Hs-mGPS values were significantly related to larger tumour size, deep tumour location, higher tumour grade and more advanced American Joint Committee on Cancer (AJCC) stage. Patients with an elevated SII had a shorter median survival time and a lower 5-year OS rate than those with a low SII. And patients with low Hs-mGPS had longer median OS and DFS. Multivariate analysis revealed that both the SII and the Hs-mGPS were independent predictive indicators for OS. And a joint model containing both the Hsm-GPS and the SII appeared to have the strongest predictive ability. CONCLUSION: Our findings indicated that malnutrition and systemic inflammation are risk factors for the survival of STS patients after operation, and early recognition and intervention of malnutrition and systemic inflammation may help to improve the survival of the patients.

The Impact of Unplanned Excision on the Outcomes of Patients With Soft Tissue Sarcoma of the Trunk and Extremity: A Propensity Score Matching Analysis.

BACKGROUND: Unplanned excision (UPE) of soft tissue sarcoma (STS) is often chosen in the early phase by general physicians without any radiological evaluation. PURPOSE: The present study aimed to evaluate the impact of UPE on the clinical outcomes of patients with STS of the trunk and extremity. MATERIALS AND METHODS: Patients with STS of the trunk and extremity who underwent R0 resection between 1998 and 2016 were included and divided into the UPE and planned excision (PE) groups. Propensity score matching (PSM) was used to control the selection bias. The endpoints were disease-specific survival (DSS), local recurrence-free survival (LRFS), and metastasis-free survival (MFS). RESULTS: In total, 458 patients (277 males, 181 females; median age: 43 years) were included: 329 (71.8%) in the PE group and 129 (28.2%) in the UPE group. The follow-up time ranged from 7.1 to 313.78 months, with a median of 112.18 months. UPE patients were more likely to have a smaller or superficial lesion and were more frequently administered adjuvant therapy. After PSM, compared with the PE group, the UPE group had a longer LRFS (P=0.015), but there was no difference between the two groups regarding DSS and MFS. Residual disease was observed in 77.5% of the re-resected specimens in the UPE group and was a risk factor for DSS (P = 0.046) and MFS (P = 0.029) but was not associated with local recurrence (LR) (P=0.475) or LRFS (P=0.334). Moreover, we found no difference in DSS, LRFS or MFS according to the interval from UPE to definitive resection. CONCLUSION: STS treated with UPE had distinct characteristics. Patients who undergo UPE followed by an additional wide R0 resection have similar oncological survival compared to patients who undergo an initial PE, although the high incidence of residual tumor in the UPE group leads to an unfavorable clinical course.