Efficacy, Safety, and Challenges of CAR T-Cells in the Treatment of Solid Tumors

Immunotherapy has been the fifth pillar of cancer treatment in the past decade. Chimeric antigen receptor (CAR) T-cell therapy is a newly designed adoptive immunotherapy that is able to target and further eliminate cancer cells by engaging with MHC-independent tumor-antigens. CAR T-cell therapy has exhibited conspicuous clinical efficacy in hematological malignancies, but more than half of patients will relapse. Of note, the efficacy of CAR T-cell therapy has been even more disappointing in solid tumors. These challenges mainly include (1) the failures of CAR T-cells to treat highly heterogeneous solid tumors due to the difficulty in identifying unique tumor antigen targets, (2) the expression of target antigens in non-cancer cells, (3) the inability of CAR T-cells to effectively infiltrate solid tumors, (4) the short lifespan and lack of persistence of CAR T-cells, and (5) cytokine release syndrome and neurotoxicity. In combination with these characteristics, the ideal CAR T-cell therapy for solid tumors should maintain adequate T-cell response over a long term while sparing healthy tissues. This article reviewed the status, clinical application, efficacy, safety, and challenges of CAR T-cell therapies, as well as the latest progress of CAR T-cell therapies for solid tumors. In addition, the potential strategies to improve the efficacy of CAR T-cells and prevent side effects in solid tumors were also explored.

IFNγ enhances cytotoxic efficiency of the cytotoxic T lymphocytes against human glioma cells

Cytotoxic T lymphocytes (CTLs) are a key player in cancer immunotherapies, and MHC class I molecules on the cell surface are crucial for cellular recognition. However, the aberrant expression of MHC class I molecules is frequently found in various malignancies. IFNγ has dual functions in cancer progression, and its effect on tumor immunity is controversial. To investigate whether IFNγ can enhance cytotoxic efficiency of the tumor antigen-specific CTLs, we generated the CTLs using modified human dendritic cells as antigen presenting cells, then studied the activities of CTLs on human leukocyte antigen (HLA)-A2 positive glioma cells treated with, or without IFNγ. The results from both ELISpot and cytotoxicity assays demonstrated that the CTLs recognized and eliminated the HLA-A2 positive glioma cells treated with IFNγ more effectively when compared to the glioma cells deprived of IFNγ treatment. In addition, in vitro experiments showed that the levels of MHC class I molecules were upregulated in all of the HLA-A2 positive glioma cells. Using the publicly accessed TCGA data of low-grade glioma, we found significantly positive associations between IFNγ and both MHC class I molecules and CD8+ T cell activation score (p<0.0001). Furthermore, we found a significantly reduced risk of death in the glioma patients with high T cell activation score in comparison to those with low score (p=0.022). These findings suggest that a clinical application of IFNγ treatment may have potential benefits.

In vitro biological activities of transmembrane superantigen staphylococcal enterotoxin A fusion protein

The bacterial superantigen staphylococcal enterotoxin A (SEA) stimulates T cells bearing certain TCR Vbeta domains when binding to MHC II molecules, and is a potent inducer of CTL activity and cytokine production. Antibody-targeted SEA such as C215 Fab-SEA and C242 Fab-SEA has been investigated for cancer therapy in recent years. We have previously reported significant tumor inhibition and prolonged survival time in tumor-bearing mice treated with a combination of both C215Fab-SEA and Ad IL-18 (Wang et al., Gene Therapy 8:542-550, 2001). In order to develop SEA as an universal biological preparation in cancer therapy, we first cloned a SEA gene from S. aureus (ATCC 13565) and a transmembrane (TM) sequence from a c- erb-b2 gene derived from human ovarian cancer cell line HO-8910, then generated a TM-SEA fusion gene by using the splice overlap extension method, and constructed the recombinant expression vector pET-28a-TM-SEA. Fusion protein TM-SEA was expressed in E. coli BL21(DE3)pLysS and purified by using the histidine tag in this vector. Purified TM-SEA spontaneously associated with cell membranes as detected by flow cytometry. TM-SEA stimulated the proliferation of both human PBLs and splenocytes derived from C57BL/6 (H-2b) mice in vitro. This study thus demonstrated a novel strategy for anchoring superantigen SEA onto the surfaces of tumor cells without any genetic manipulation.

Artificial human antigen-presenting cells are superior to dendritic cells at inducing cytotoxic T-cell responses

Peptide recognition through the MHC class I molecule by cytotoxic T lymphocytes (CTLs) leads to the killing of cancer cells. A potential challenge for T-cell immunotherapy is that dendritic cells (DCs) are exposed to the MHC class I-peptide complex for an insufficient amount of time. To improve tumour antigen presentation to T cells and thereby initiate a more effective T-cell response, we generated artificial antigen-presenting cells (aAPCs) by incubating human immature DCs (imDCs) with poly(lactic-co-glycolic) acid nanoparticles (PLGA-NPs) encapsulating tumour antigenic peptides, followed by maturation with lipopolysaccharide. Tumour antigen-specific CTLs were then induced using either peptide-loaded mature DCs (mDCs) or aAPCs, and their activities were analysed using both ELISpot and cytotoxicity assays. We found that the aAPCs induced significantly stronger tumour antigen-specific CTL responses than the controls, which included both mDCs and aAPCs loaded with empty nanoparticles. Moreover, frozen CTLs that were generated by exposure to aAPCs retained the capability to eradicate HLA-A2-positive tumour antigen-bearing cancer cells. These results indicated that aAPCs are superior to DCs when inducing the CTL response because the former are capable of continuously presenting tumour antigens to T cells in a sustained manner. The development of aAPCs with PLGA-NPs encapsulating tumour antigenic peptides is a promising approach for the generation of effective CTL responses in vitro and warrants further assessments in clinical trials.

In silico designed mRNA vaccines targeting CA-125 neoantigen in breast and ovarian cancer

Somatic mutation-derived neoantigens are associated with patient survival in breast and ovarian cancer. These neoantigens are targets for cancer, as shown by the implementation of neoepitope peptides as cancer vaccines. The success of cost-effective multi-epitope mRNA vaccines against SARS-Cov-2 in the pandemic established a model for reverse vaccinology. In this study, we aimed to develop an in silico pipeline designing an mRNA vaccine of the CA-125 neoantigen against breast and ovarian cancer, respectively. Using immuno-bioinformatics tools, we predicted cytotoxic CD8+ T cell epitopes based on somatic mutation-driven neoantigens of CA-125 in breast or ovarian cancer, constructed a self-adjuvant mRNA vaccine with CD40L and MHC-I -targeting domain to enhance cross-presentation of neoepitopes by dendritic cells. With an in silico ImmSim algorithm, we estimated the immune responses post-immunization, showing IFN-γ and CD8+ T cell response. The strategy described in this study may be scaled up and implemented to design precision multi-epitope mRNA vaccines by targeting multiple neoantigens.

Inflammation-driven deaminase deregulation fuels human pre-leukemia stem cell evolution

Inflammation-dependent base deaminases promote therapeutic resistance in many malignancies. However, their roles in human pre-leukemia stem cell (pre-LSC) evolution to acute myeloid leukemia stem cells (LSCs) had not been elucidated. Comparative whole-genome and whole-transcriptome sequencing analyses of FACS-purified pre-LSCs from myeloproliferative neoplasm (MPN) patients reveal APOBEC3C upregulation, an increased C-to-T mutational burden, and hematopoietic stem and progenitor cell (HSPC) proliferation during progression, which can be recapitulated by lentiviral APOBEC3C overexpression. In pre-LSCs, inflammatory splice isoform overexpression coincides with APOBEC3C upregulation and ADAR1p150-induced A-to-I RNA hyper-editing. Pre-LSC evolution to LSCs is marked by STAT3 editing, STAT3β isoform switching, elevated phospho-STAT3, and increased ADAR1p150 expression, which can be prevented by JAK2/STAT3 inhibition with ruxolitinib or fedratinib or lentiviral ADAR1 shRNA knockdown. Conversely, lentiviral ADAR1p150 expression enhances pre-LSC replating and STAT3 splice isoform switching. Thus, pre-LSC evolution to LSCs is fueled by primate-specific APOBEC3C-induced pre-LSC proliferation and ADAR1-mediated splicing deregulation.

BRCA1 mRNA expression modifies the effect of T cell activation score on patient survival in breast cancer

BACKGROUND

Effector CD8+ T cell activation and its cytotoxic function to eradicate tumor cells depend on the T cell recognition of tumor neoantigens, and are positively associated with improved survival in breast cancer. Tumor suppressor BRCA1 and cell cycle regulator CCND1 play a critical role in maintaining genome integrity and tumorigenesis, respectively. However, it is still unclear how BRCA1 and CCND1 expression levels affect the effect of T cell activation on breast cancer patient survival.

METHODS

The interactions between T cell activation status and either BRCA1 or CCND1 expression were evaluated using Kaplan-Meier survival curves and multivariate Cox regression models in a public dataset with 1088 breast cancer patients.

RESULTS

Among the patients with low BRCA1 or CCND1 expression, the Activation group showed better overall survival than the Exhaustion group. Adjusted hazards ratios were 0.43 (95% CI: 0.20-0.93) in patients with a low BRCA1 level, and 0.39 (95% CI: 0.19-0.81) in patients with a low CCND1 level, respectively. There was a significant trend in both subgroups (p-trend = 0.011 in the low BRCA1 group, and p-trend = 0.009 in the low CCND1 group). In contrast, there is no significant association in patients with either high BRCA1 or high CCND1 levels. There is a significant interaction between T cell activation status and BRCA1 level (p = 0.009), but not between T cell activation status and CCND1 level (p = 0.135).

CONCLUSIONS

BRCA1 expression modified the effect of T cell activation status on patient survival in breast cancer, suggesting that the existence of neoantigens and the enhancement of neoantigen presentation in combination with immune checkpoint blockade may have synergistic effects on patient outcome.

Potent antitumor effect elicited by superantigen-linked tumor cells transduced with heat shock protein 70 gene

Heat shock proteins (HSP) induce antitumor-specific immunity via a unique mechanism, but HSP alone fails to produce a satisfactory antitumor efficacy. We considered that the potent immune-activation of superantigen (SAg) might assist HSP to elicit a strong tumor-antigen-specific immunity. We initially prepared B16 melanoma cells linked to SAg SEA via a fusion protein with a transmembrane sequence (TM), and demonstrated that SEA thus anchored on the tumor cell surface could elicit strong antitumor immunity. We then prepared cells transduced with an inducible heat shock protein 70 (HSP70) gene, and bearing SEA-TM fusion protein on the cell surface, and used these cells as a dual-modified vaccine. In this study, either in a therapeutic setting or in a pre-immune model, the SEA-anchored vaccine or the HSP70 gene-modified vaccine induced marked tumor suppression, prolonged survival, augmented lymphocyte proliferation and higher NK and CTL activity in C57BL/6 mice compared with their controls (P < 0.01), though they were less effective than the dual-modified vaccine. Among these vaccines, the dual-modified vaccine showed the best therapeutic efficacy in B16 melanoma-bearing mice and gave the greatest protection against wild-type B16 melanoma challenge. The results indicated that the dual-modified vaccine could induce a potent tumor-antigen-specific immune response in addition to an increase of non-specific immunity. This study offers a novel approach to bridging specific and non-specific immunity for cancer therapy.

A novel approach for cancer immunotherapy: tumor cells with anchored superantigen SEA generate effective antitumor immunity

Murine B16 melanoma cell line is poorly immunogenic and highly aggressive. We recently reported that the transmembrane staphylococcal enterotoxin A (TM-SEA) anchors onto B16 cells and stimulates lymphocyte proliferation. The purpose of the study was to investigate whether vaccination with B16 cells bearing membrane-anchored TM-SEA fusion protein could cause tumor-specific immunity. Mice in the therapeutic vaccination group received B16 tumor inoculations, followed by treatment with B16-TM-SEA vaccine or control vaccines. Mice in the prophylactic vaccination group were given B16-TM-SEA vaccine or control vaccines, followed by challenge with wild type B16 or control EL4 cells. Significant tumor growth inhibition, prolongation of survival, and marked augmentation of NK and CTL activities were observed in mice which received B16-TM-SEA vaccine as compared to controls. Overall, our results suggest that the TM-SEA cellular vaccine is a novel and effective strategy for cancer immunotherapy.

Epithelial membrane protein 2: a novel biomarker for circulating tumor cell recovery in breast cancer

PURPOSE

EpCAM is a common marker used in the detection of circulating tumor cells (CTC). Disseminated cancer cells display the characteristics of epithelial-to-mesenchymal transition events. The purpose of this study was to assess the potential of epithelial membrane protein 2 (EMP2) as a novel biomarker for CTC retrieval in breast cancer.

METHODS

MCF7 and MDA-MB-231 cells were stained with either anti-EpCAM or anti-EMP2 mAbs, respectively, followed by flow cytometric assay to measure their expression levels. PBMCs isolated from healthy donors were used for breast cancer cell spiking. CD45-depleted PBMCs from breast cancer patients' blood were used for CTC capturing. Immunomagnetic separation was used to enrich breast cancer cells. Cytospin centrifugation was performed to concentrate the captured cells, followed by immunofluorescence staining with anti-CD45 mAb, anti-pan cytokeratin mAb and DAPI. Fluorescent images were taken using a confocal microscope for CTC counts.

RESULT

MDA-MB-231 cells had 2.56 times higher EMP2 expression than MCF7 cells, and EMP2 had a significantly higher capture efficiency than EpCAM for MCF7 cells. Furthermore, anti-EMP2 was capable of capturing MCF7 cells that escaped in the flow-through of anti-EpCAM. Likewise, EMP2 had a significantly higher capture efficiency on MDA-MB-231 cells when compared to MCF7 cells. Most importantly, EMP2 biomarker was successfully used for CTC capture in patients with primary breast cancer.

CONCLUSIONS

EMP2 is superior to EpCAM for capturing both MCF7 and MDA-MB-231 cells. Additionally, EMP2 is a novel biomarker and capable of capturing breast cancer cells in patient blood samples.

The prognostic value of adhesion molecule CD44v6 in women with primary breast carcinoma: a clinicopathologic study

AIMS

CD44 functions as an adhesion molecule. Within the family of CD44 isoforms, the spliced variant 6 has been causally associated with the development of metastases and poor prognosis in animal models and several human cancers. The aim of this study was to investigate the prognostic value of CD44v6 in women with primary breast carcinoma.

MATERIALS AND METHODS

The women with primary breast carcinoma in this study were followed up clinically for a period of 5 years. Clinicopathologic features, including tumour size, axillary nodal status, histological grade and pTNM stage, were determined for a cohort of 78 women presenting with primary breast carcinoma. Standard immunohistochemistry was used to explore CD44v6 expression. The data obtained were analysed by univariate and multivariate analyses.

RESULTS

Forty-three out of 78 (55%) women with breast carcinoma were CD44v6-positive (i.e. over 5% of tumour cells exhibited positive staining). Significant sequential increase of CD44v6 expression was observed in women with metastases of axillary nodes, tumour size more than 2 cm, advanced pTNM stage and survival period less than 5 years. Univariate analysis showed that axillary nodal status, primary tumour size, histological grade, and pTNM stage were associated with 5-year survival, and CD44v6 expression was associated with primary tumour size, axillary nodal status, pTNM stage and 5-year survival. In multivariate analysis, using the Cox-regression model, CD44v6 expression was not an independent prognostic factor.

CONCLUSIONS

CD44v6 expression was correlated with tumour size, metastases of axillary nodes, pTNM stage, and 5-year survival; however, multivariate analysis revealed that CD44v6 expression failed to be an independent predictor of patient prognosis.

Biomarker discovery in hepatocellular carcinoma (HCC) for personalized treatment and enhanced prognosis

Hepatocellular carcinoma (HCC) is a leading contributor to cancer-related deaths worldwide and presents significant challenges in diagnosis and treatment due to its heterogeneous nature. The discovery of biomarkers has become crucial in addressing these challenges, promising early detection, precise diagnosis, and personalized treatment plans. Key biomarkers, such as alpha fetoprotein (AFP) glypican 3 (GPC3) and des gamma carboxy prothrombin (DCP) have shown potential in improving clinical results. Progress in proteomic technologies, including next-generation sequencing (NGS), mass spectrometry, and liquid biopsies detecting circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), has deepened our understanding of HCC's molecular landscape. Immunological markers, like PD-L1 expression and tumor-infiltrating lymphocytes (TILs), also play a crucial role in guiding immunotherapy decisions. Despite these advancements, challenges remain in biomarker validation, standardization, integration into clinical practice, and cost-related barriers. Emerging technologies like single-cell sequencing and machine learning offer promising avenues for further exploration. Continued investment in research and collaboration among researchers, healthcare providers, and policymakers is vital to harness the potential of biomarkers fully, ultimately revolutionizing HCC management and improving patient outcomes through personalized treatment approaches.

Immunopathological changes, complications, sequelae and immunological memory in COVID-19 patients

Confirmed SARS-CoV-2-caused disease (COVID-19) cases have reached 275.65 million worldwide. Although the majority of COVID-19 patients present mild to moderate symptoms, some have severe complications including death. We first reviewed the pathogenesis on ACE2, a binding receptor of SARS-CoV-2 expressed in multiple organs, and prevalent multinucleate syncytia in the lung tissues of COVID-19 patients. Then, we evaluated the pathological, immunological changes and sequelae in the major organs. Finally, we reviewed the immunological memory after SARS-CoV-2 infection and vaccination. The binding of SARS-Cov-2 to ACE2 receptor results in reduced ACE2 protein levels, which may lead to elevated susceptibility to inflammation, cell death, organ failure, and potentially severe illness. These damages increase the risk of health problems over a long period, which result in many complications. The complications in multiple organs lead to the increased risk of long-term health problems that require additional attention. A multidisciplinary care team is necessary for further management and recovery of the COVID-19 survivors. Many COVID-19 patients will probably make antibodies against SARS-CoV-2 virus for most of their lives, and the immunity against reinfection would last for 3-61 months.

Navigating the Immune Maze: Pioneering Strategies for Unshackling Cancer Immunotherapy Resistance

Cancer immunotherapy has ushered in a transformative era in oncology, offering unprecedented promise and opportunities. Despite its remarkable breakthroughs, the field continues to grapple with the persistent challenge of treatment resistance. This resistance not only undermines the widespread efficacy of these pioneering treatments, but also underscores the pressing need for further research. Our exploration into the intricate realm of cancer immunotherapy resistance reveals various mechanisms at play, from primary and secondary resistance to the significant impact of genetic and epigenetic factors, as well as the crucial role of the tumor microenvironment (TME). Furthermore, we stress the importance of devising innovative strategies to counteract this resistance, such as employing combination therapies, tailoring immune checkpoints, and implementing real-time monitoring. By championing these state-of-the-art methods, we anticipate a paradigm that blends personalized healthcare with improved treatment options and is firmly committed to patient welfare. Through a comprehensive and multifaceted approach, we strive to tackle the challenges of resistance, aspiring to elevate cancer immunotherapy as a beacon of hope for patients around the world.

Breast Cancer Patients: Who Would Benefit from Neoadjuvant Chemotherapies?

Neoadjuvant chemotherapy (NACT) was developed with the aims of shrinking tumors or stopping cancer cells from spreading before surgery. Unfortunately, not all breast cancer patients will benefit from NACT, and thus, patients must weigh the risks and benefits of treatment prior to the initiation of therapy. Currently, the data for predicting the efficacy of NACT is limited. Molecular testing, such as Oncotype DX, MammaPrint, and Curebest 95GC, have been developed to assist which breast cancer patients will benefit from the treatment. Patients with an increased level of Human Leukocyte Antigen-DR isotype, tumor-infiltrating lymphocytes, Fizzy-related protein homolog, and a decreased level of tumor-associated macrophages appear to benefit most from NACT.

Preparation of murine B7.1-glycosylphosphatidylinositol and transmembrane-anchored staphylococcal enterotoxin. A dual-anchored tumor cell vaccine and its antitumor effect

BACKGROUND

The authors have previously reported a tumor cell vaccine modified with superantigen staphylococcal enterotoxin A (SEA) and its antitumor effect. The tumor cell vaccines modified with multiple immune activators frequently elicited stronger immune responses against established tumors than single-modified vaccines.

METHODS

The authors explored the effectiveness of a tumor cell vaccine transduced with immune activators, dual-modified using the protein transfer technique. First, a glycosylphosphatidylinositol (GPI)-anchored murine B7.1 (mB7.1-GPI) and a transmembrane-anchored SEA (TM-SEA) were genetically generated. Then, the murine lymphoma EL4 cells were dual modified with the incorporation of mB7.1-GPI and TM-SEA onto the cell surface. Flow cytometry and laser confocal microscopy showed that the incorporation of B7.1 and SEA molecules onto EL4 cells was quite stable.

RESULTS

The dual-modified tumor cell vaccine EL4/mB7.1-GPI + TM-SEA elicited significantly stronger antitumor immune responses both in vitro and in vivo when compared with the single-modified tumor cell vaccines EL4/mB7.1-GPI and EL4/TM-SEA.

CONCLUSIONS

The results of the current study validated the novel approach for preparing tumor cell vaccines modified with dual immune active molecules using the protein transfer technique, and supported the feasibility and effectiveness of the dual-modified tumor cell vaccine.

Metastasis-Associated Protein 1 Is Involved in Angiogenesis after Transarterial Chemoembolization Treatment

BACKGROUND

Transarterial chemoembolization (TACE), a well-established treatment for unresectable hepatocellular carcinoma (HCC), blocks the arterial blood supply to the tumor, which can be short-lived as development of collateral neovessels, leading to the failure of treatment. Metastasis-associated protein 1 (MTA1) is involved in development of tumors and metastases. However, the role of MTA1 in angiogenesis is still obscure.

METHODS

We detected the expression of MTA1 and hypoxia-inducible factor-1α (HIF-1α) and microvessel density (MVD) value in liver tumor tissues and tumor periphery before and after TACE treatment. Hepatocellular carcinoma cell line HepG2, tube formation assay, and chorioallantoic membrane (CAM) assay were applied to explore the mechanism of MTA1 in angiogenesis.

RESULTS

We found that expression of MTA1 increased after TACE treatment, especially in tumor periphery, which was accompanied by markedly elevated MVD value, indicating a significant correlation between MTA1 and MVD value. Moreover, MTA1 contributed to neovascularization of residual tumors. Cellular experiments further revealed that MTA1 increased the stability and the expression of HIF-1α, and overexpression of MTA1 enhanced tube formation and neovessels of chick embryos.

CONCLUSIONS

MTA1 is an active angiogenic regulator; our results shed light on better understanding in neovascularization, which are helpful to predict prognosis of TACE, and provide evidences for intervention to improve therapeutic effects on HCC.

Frontiers in pancreatic cancer on biomarkers, microenvironment, and immunotherapy

Pancreatic cancer remains one of the most challenging malignancies to treat due to its late-stage diagnosis, aggressive progression, and high resistance to existing therapies. This review examines the latest advancements in early detection, and therapeutic strategies, with a focus on emerging biomarkers, tumor microenvironment (TME) modulation, and the integration of artificial intelligence (AI) in data analysis. We highlight promising biomarkers, including microRNAs (miRNAs) and circulating tumor DNA (ctDNA), that offer enhanced sensitivity and specificity for early-stage diagnosis when combined with multi-omics panels. A detailed analysis of the TME reveals how components such as cancer-associated fibroblasts (CAFs), immune cells, and the extracellular matrix (ECM) contribute to therapy resistance by creating immunosuppressive barriers. We also discuss therapeutic interventions that target these TME components, aiming to improve drug delivery and overcome immune evasion. Furthermore, AI-driven analyses are explored for their potential to interpret complex multi-omics data, enabling personalized treatment strategies and real-time monitoring of treatment response. We conclude by identifying key areas for future research, including the clinical validation of biomarkers, regulatory frameworks for AI applications, and equitable access to innovative therapies. This comprehensive approach underscores the need for integrated, personalized strategies to improve outcomes in pancreatic cancer.

The prognostic relevance of preoperative transcatheter arterial chemoembolization (TACE) and PCNA/VEGF expression in patients with Wilms' tumour

BACKGROUND

Wilms' tumour is the most frequent renal tumour in children. Based on the SIOP strategy, children with Wilms' tumour may benefit from preoperative chemotherapy, but few publications address the effect of preoperative transcatheter arterial chemoembolization (TACE) on patients with Wilms' tumours. The aims of this study were to investigate the prognostic relevance of preoperative TACE followed by tumour resection, proliferating cell nuclear antigen (PCNA) and vascular endothelial growth factor (VEGF) expression in patients with Wilms' tumours.

MATERIALS AND METHODS

Two therapeutic strategies including tumour resection only and TACE, followed by tumour resection were conducted in a cohort of 44 patients with Wilms' tumours. Clinical and follow-up data was analysed. Immunohistochemistry staining was used to explore PCNA and VEGF expression in the Wilms' tumour.

RESULTS

Two years tumour-free survival of the patients in the TACE group was significantly higher than that of the patients in the control group (P < 0.001) and recurrence and cases of death within one year in the TACE group was markedly lower than that in the control group (P < 0.001). Fifty-five percent of patients in the control group were PCNA-positive vs. 4.17% of patients in the TACE group (P < 0.001). Fifty percent of patients in the control group were VEGF-positive vs. 29.17% of patients in the TACE group (P > 0.05).

CONCLUSIONS

Patients with Wilms' tumours benefited from preoperative TACE treatment. PCNA expression was significantly lower in patients in the TACE group than those in the control group. There was no significant difference on VEGF expression between the patients in TACE and control groups.

Reversal of malignant ADAR1 splice isoform switching with Rebecsinib

Adenosine deaminase acting on RNA1 (ADAR1) preserves genomic integrity by preventing retroviral integration and retrotransposition during stress responses. However, inflammatory-microenvironment-induced ADAR1p110 to p150 splice isoform switching drives cancer stem cell (CSC) generation and therapeutic resistance in 20 malignancies. Previously, predicting and preventing ADAR1p150-mediated malignant RNA editing represented a significant challenge. Thus, we developed lentiviral ADAR1 and splicing reporters for non-invasive detection of splicing-mediated ADAR1 adenosine-to-inosine (A-to-I) RNA editing activation; a quantitative ADAR1p150 intracellular flow cytometric assay; a selective small-molecule inhibitor of splicing-mediated ADAR1 activation, Rebecsinib, which inhibits leukemia stem cell (LSC) self-renewal and prolongs humanized LSC mouse model survival at doses that spare normal hematopoietic stem and progenitor cells (HSPCs); and pre-IND studies showing favorable Rebecsinib toxicokinetic and pharmacodynamic (TK/PD) properties. Together, these results lay the foundation for developing Rebecsinib as a clinical ADAR1p150 antagonist aimed at obviating malignant microenvironment-driven LSC generation.

A novel anticancer approach: SEA-anchored tumor cells expressing heat shock protein 70 onto the surface elicit strong anticancer efficacy

Heat shock proteins (HSP) are attractive for their initiation of anticancer specific immunity via a distinct mechanism. To facilitate the induction process, we targeted HSP onto vaccine cell surface genetically. Then, SEA (a typical superantigen) was anchored on the cells by its fusion protein with transmembrane sequence, in order to produce immune-activated microsurrounding for further improvement of specific immunity. Thereby, the dual-modified vaccine, the surface-targeting-HSP70 and SEA-anchored vaccine, was developed successfully. Both in a therapeutic setting and in a pre-immune model, the mice vaccinated with the dual-modified vaccine displayed significant lymphocyte proliferation, higher NK and CTL activity, marked tumor suppression and prolonged survival when compared with those vaccinated with the vaccine modified alone with surface-targeting HSP70 or the SEA-anchored vaccine. Of all the vaccines, the dual-modified vaccine generated the best therapeutic efficacy on melanoma-bearing mice, the strongest protection against melanoma challenge. These results suggested that the dual-modified vaccine could induce more potent anticancer specific immunity while non-specific immunity was augmented.

Novel Survivin Peptides Screened With Computer Algorithm Induce Cytotoxic T Lymphocytes With Higher Cytotoxic Efficiency to Cancer Cells

The identification of novel biomarkers and therapeutic targets in advanced cancer is critical for improving cancer diagnosis and therapeutics. Survivin (SV) is highly expressed predominantly in most cancer cells and tissues but is absent or undetectable in terminally differentiated normal adult tissues. Therefore, it functions as an almost universal tumor antigen. Peptides are short chains of amino acids linked by peptide bonds. To obtain novel SV decamers that are able to induce SV-specific cytotoxic T lymphocytes (CTLs) with a higher cytotoxic efficiency against cancer cells, major histocompatibility complex (MHC) peptide binding algorithms were conducted to predict nine modified SV95 decamers (from SV95-2 to SV95-10) based on the natural SV95-104 peptide sequence of ELTLGEFLKL (here defined as SV95-1). The fluorescent density of each SV95 peptide was determined by a MHC stability assay, followed by the generation of SV95-specific CTLs with each SV95 peptide (from SV95-1 to SV95-10) and human dendritic cells (DCs) loaded with Poly(lactic-co-glycolic) acid (PLGA) nanoparticles encapsulated with SV95 peptide. Finally, IFN-γ ELISpot and CytoTox 96® Non-Radioactive Cytotoxicity Assays were employed to verify their cytotoxic efficiency of the SV95-specific CTLs generated with the corresponding artificial antigen presenting cells (aAPCs) containing SV95 (SV95-1 to SV95-10) peptide. Furthermore, the cytotoxicity of the SV95 specific CTLs generated with nine mutated SV95 peptides was compared to the one generated with natural SV95-1 peptide and TIL2080 cells. The results indicated that the HLA-A2-restricted mutated SV95 epitope decamers (SV95-6 and SV95-7) showed significant higher binding ability compared to natural peptide SV95-1 in MHC stability assay. More importantly, SV95-specific CTLs with higher cytotoxicity were successfully induced with both SV95-6 and SV95-7 peptides, which significantly eliminated target cells (not only SV95-1 peptide pulsed T2 cells, but also both HLA-A2 and SV positive cancer cells) when compared to those generated with natural SV95-1 peptide and TIL2080 cells. These findings suggest that the SV95-6 and SV95-7 peptides are two novel HLA-A2-restricted CTL epitopes and may be useful for the immunotherapy for patients with survivin expressing cancer.

Malignant A-to-I RNA editing by ADAR1 drives T cell acute lymphoblastic leukemia relapse via attenuating dsRNA sensing

Leukemia-initiating cells (LICs) are regarded as the origin of leukemia relapse and therapeutic resistance. Identifying direct stemness determinants that fuel LIC self-renewal is critical for developing targeted approaches. Here, we show that the RNA-editing enzyme ADAR1 is a crucial stemness factor that promotes LIC self-renewal by attenuating aberrant double-stranded RNA (dsRNA) sensing. Elevated adenosine-to-inosine editing is a common attribute of relapsed T cell acute lymphoblastic leukemia (T-ALL) regardless of molecular subtype. Consequently, knockdown of ADAR1 severely inhibits LIC self-renewal capacity and prolongs survival in T-ALL patient-derived xenograft models. Mechanistically, ADAR1 directs hyper-editing of immunogenic dsRNA to avoid detection by the innate immune sensor melanoma differentiation-associated protein 5 (MDA5). Moreover, we uncover that the cell-intrinsic level of MDA5 dictates the dependency on the ADAR1-MDA5 axis in T-ALL. Collectively, our results show that ADAR1 functions as a self-renewal factor that limits the sensing of endogenous dsRNA. Thus, targeting ADAR1 presents an effective therapeutic strategy for eliminating T-ALL LICs.

Correction: BCMA peptide-engineered nanoparticles enhance induction and function of antigen-specific CD8+ cytotoxic T lymphocytes against multiple myeloma: clinical applications

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Intracellular delivery of tumor antigenic peptides in biodegradable-polymer adjuvant for enhancing cancer immunotherapy

Tumor antigenic peptides therapeutics is a promising field for cancer immunotherapy; advantages include convenient synthesis and modification of antigenic peptides, as well as little toxicity associated with its administration. Vaccination of the peptides derived from tumor-associated antigen (TAA) was specifically designed for T cells in the context of MHC molecules. In the past decades, tumor antigenic peptides have been examined in clinic but numbered success has been obtained because of the stability of peptide and delivery approaches, consequently leading to an inefficient antigen presentation and low response rates in cancer patients. Thus, the appropriate and efficient peptide vaccine carrier systems still continue to be a major obstacle. However, both sipuleucel-T vaccine and anti-CTLA-4 antibody have been approved by FDA for the treatment of metastatic prostate cancer and melanoma, respectively. PLGA has been recently used as the adjuvant to elicit enhanced immune responses while delivering tumor antigenic peptides. Intracellular delivery of the peptides derived from TAA into DCs would prolong antigen presentation of APC to T cells. This article aims to describe a new delivery method regarding tumor antigenic peptides and rationales of DCs-based vaccination.