Immune-resistant mechanisms in cancer immunotherapy

CD155 expression and co-expression with PD-L1 are not associated with poor prognosis in patients with stage II and III lung adenocarcinoma undergoing surgical resection

BACKGROUND

CD155 has been identified as a ligand for T-cell immunoreceptor with Ig and ITIM domains. Herein, we investigated the relationship between the expressions of CD155 and programmed cell death-ligand 1 (PD-L1) and clinical outcomes in patients with surgically resected lung adenocarcinoma.

METHODS

This study included 426 patients diagnosed with pathological stage (pStage) I-III lung adenocarcinoma who underwent surgery at Kyushu University Hospital. The number of tumor cells expressing CD155 and PD-L1 was assessed by immunohistochemistry, and the clinical significance of CD155 expression and CD155/PD-L1 co-expression in prognosis was investigated.

RESULTS

Among the enrolled cohort, 320 (75.1%), 60 (14.1%), and 46 (10.8%) patients were diagnosed with pStage I, II, and III, respectively. Tissues from 112 patients (26.3%) were classified as having high CD155 expression. Co-expression of CD155 and PD-L1 was observed in 44 patients (10.3%). The High CD155 and CD155/PD-L1 co-expression groups had significantly poorer prognosis in pStage I-III lung adenocarcinoma. However, subgroup analysis revealed that the clinical significance of both CD155 expression and CD155/PD-L1 co-expression differed widely between patients with pStage I and II-III. Multivariate Cox proportional hazards regression analyses showed that high CD155 expression and CD155/PD-L1 co-expression were not independent poor prognostic factors in pStage II-III lung adenocarcinoma.

CONCLUSION

Our findings suggest that neither CD155 expression or CD155/PD-L1 co-expression are associated with poor prognosis in pStage II-III lung adenocarcinoma.

Immune response recalibration using immune therapy and biomimetic nano-therapy against high-grade gliomas and brain metastases

Although with aggressive standards of care like surgical resection, chemotherapy, and radiation, high-grade gliomas (HGGs) and brain metastases (BM) treatment has remained challenging for more than two decades. However, technological advances in this field and immunotherapeutic strategies have revolutionized the treatment of HGGs and BM. Immunotherapies like immune checkpoint inhibitors, CAR-T targeting, oncolytic virus-based therapy, bispecific antibody treatment, and vaccination approaches, etc., are emerging as promising avenues offering new hope in refining patient's survival benefits. However, selective trafficking across the blood-brain barrier (BBB), immunosuppressive tumor microenvironment (TME), metabolic alteration, and tumor heterogeneity limit the therapeutic efficacy of immunotherapy for HGGs and BM. Furthermore, to address this concern, the NanoBioTechnology-based bioinspired delivery system has been gaining tremendous attention in recent years. With technological advances such as Trojan horse targeting and infusing/camouflaging nanoparticles surface with biological molecules/cells like immunocytes, erythrocytes, platelets, glioma cell lysate and/or integrating these strategies to get hybrid membrane for homotypic recognition. These biomimetic nanotherapy offers advantages over conventional nanoparticles, focusing on greater target specificity, increased circulation stability, higher active loading capacity, BBB permeability (inherent inflammatory chemotaxis of neutrophils), decreased immunogenicity, efficient metabolism-based combinatorial effects, and prevention of tumor recurrence by induction of immunological memory, etc. provide new age of improved immunotherapies outcomes against HGGs and BM. In this review, we emphasize on neuro-immunotherapy and the versatility of these biomimetic nano-delivery strategies for precise targeting of hard-to-treat and most lethal HGGs and BM. Moreover, the challenges impeding the clinical translatability of these approaches were addressed to unmet medical needs of brain cancers.

Targeting HGF/c-MET signaling to regulate the tumor microenvironment: Implications for counteracting tumor immune evasion

The hepatocyte growth factor (HGF) along with its receptor (c-MET) are crucial in preserving standard cellular physiological activities, and imbalances in the c-MET signaling pathway can lead to the development and advancement of tumors. It has been extensively demonstrated that immune checkpoint inhibitors (ICIs) can result in prolonged remission in certain patients. Nevertheless, numerous preclinical studies have shown that MET imbalance hinders the effectiveness of anti-PD-1/PD-L1 treatments through various mechanisms. Consequently, clarifying the link between the c-MET signaling pathway and the tumor microenvironment (TME), as well as uncovering the effects of anti-MET treatment on ICI therapy, is crucial for enhancing the outlook for tumor patients. In this review, we examine the impact of abnormal activation of the HGF/c-MET signaling pathway on the control of the TME and the processes governing PD-L1 expression in cancer cells. The review thoroughly examines both clinical and practical evidence regarding the use of c-MET inhibitors alongside PD-1/PD-L1 inhibitors, emphasizing that focusing on c-MET with immunotherapy enhances the effectiveness of treating MET tumors exhibiting elevated PD-L1 expression.

Hyperprogressive disease induced by PD-1 inhibitor monotherapy in lung adenocarcinoma with HER2 exon 20 insertion: report of two cases and review of literature

Monotherapy with anti-programmed cell death protein 1 (PD-1) monoclonal antibody has been approved for the treatment of advanced non-small cell lung cancer with positive programmed cell death-ligand 1 (PD-L1) expression and oncogene wild type, which revealed survival benefit compared with chemotherapy. Nevertheless, certain patients develop rapid progression on anti-PD-1 inhibitor monotherapy. This novel pattern is called hyperprogressive disease (HPD), and the underlying mechanism and molecular characteristics still leaves not clear. Here, we reported two heavily pretreated advanced lung adenocarcinoma cases with HER2 exon 20 insertion who presented HPD after two cycles of anti-PD-1 inhibitor sintilimab monotherapy, and they both carried co-alterations in the PI3K/AKT/mTOR and cell cycle signaling pathway. We speculated that HER2 exon 20 insertion might be viewed as a potential biomarker to avoid single-agent immunotherapy in certain patients with driver mutations, or timely guide proper treatment strategies.

Efficacy of pembrolizumab in microsatellite-stable, tumor mutational burden-high metastatic colorectal cancer: genomic signatures and clinical outcomes

BACKGROUND

Pembrolizumab, an immune checkpoint inhibitor (ICI), shows significant survival benefits in patients with microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC), but its efficacy in microsatellite-stable (MSS) mCRC is limited. Although ICIs are effective in tumor mutational burden-high (TMB-H) solid tumors, the impact on MSS-TMB-H mCRC, a rare subset within MSS mCRC, remains unclear.

MATERIALS AND METHODS

We conducted a retrospective analysis using clinical and genomic data from the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) repository in Japan. Patients with MSS-TMB-H mCRC who underwent tissue-based comprehensive genomic profiling and were treated with pembrolizumab or other later-line therapies were included. Pembrolizumab's efficacy was compared with that of trifluridine/tipiracil (FTD/TPI) and regorafenib. Genomic profiles of MSS-TMB-H, MSI-H-TMB-H, and MSS-TMB-low (TMB-L) CRCs were analyzed across 71 cancer-related genes.

RESULTS

Among 127 TMB-H mCRC cases treated with pembrolizumab in the C-CAT repository, 77 were MSS and 50 were MSI-H. Pembrolizumab showed significantly shorter time to treatment failure (TTF) and overall survival (OS) in patients with MSS-TMB-H mCRC compared with those with MSI-H-TMB-H mCRC [median TTF 2.0 versus 10.6 months; hazard ratio (HR) 4.79, 95% confidence interval (CI) 2.65-8.64, median OS 4.5 versus 33.6 months; HR 9.86, 95% CI 3.93-24.77, both P < 0.0001]. Among MSS-TMB-H mCRC patients, 19 received pembrolizumab, 73 received FTD/TPI (±bevacizumab), and 18 received regorafenib as their first later-line therapy. Pembrolizumab showed significantly shorter TTF and OS compared with FTD/TPI (median TTF 1.6 versus 4.1 months; HR 2.66, 95% CI 1.41-5.02, P = 0.0017, median OS 5.4 versus 13.8 months; HR 2.42, 95% CI, 1.09-5.38, P = 0.025). Genomic analysis of 6737 CRCs revealed that MSS-TMB-H CRCs harbored fewer pathogenic alterations than MSI-H-TMB-H CRCs but had a profile similar to MSS-TMB-L CRCs.

CONCLUSIONS

Pembrolizumab may be less effective than FTD/TPI in later-line treatment of MSS-TMB-H mCRC, potentially due to genomic similarities between MSS-TMB-H and MSS-TMB-L CRC, suggesting the need for alternative therapeutic strategies in this subgroup.

Advancements in immunotherapy for colorectal cancer treatment: a comprehensive review of strategies, challenges, and future prospective

PURPOSE

Colorectal cancer (CRC) remains one of the leading causes of cancer-related mortality worldwide. Metastatic colorectal cancer (mCRC) continues to present significant challenges, particularly in patients with proficient mismatch repair/microsatellite stable (pMMR/MSS) tumors. This narrative review aims to provide recent developments in immunotherapy for CRC treatment, focusing on its efficacy and challenges.

METHODS

This review discussed the various immunotherapeutic strategies for CRC treatment, including immune checkpoint inhibitors (ICIs) targeting PD-1 and PD-L1, combination therapies involving ICIs with other modalities, chimeric antigen receptor T-cell (CAR-T) cell therapy, and cancer vaccines. The role of the tumor microenvironment and immune evasion mechanisms was also explored to understand their impact on the effectiveness of these therapies.

RESULTS

This review provides a comprehensive update of recent advancements in immunotherapy for CRC, highlighting the potential of various immunotherapeutic approaches, including immune checkpoint inhibitors, combination therapies, CAR-T therapy, and vaccination strategies. The results of checkpoint inhibitors, particularly in patients with MSI-H/dMMR tumors, which have significant improvements in survival rates have been observed. Furthermore, this review also addresses the challenges faced in treating pMMR/MSS CRC, which remains resistant to immunotherapy.

CONCLUSION

Immunotherapy plays a significant role in the treatment of CRC, particularly in patients with MSI-H/dMMR tumors. However, many challenges remain, especially in treating pMMR/MSS CRC. This review discussed the need for further research into combination therapies, biomarker development, CAR-T cell therapy, and a deeper understanding of immune evasion mechanisms for CRC treatment.

The Novel HDAC Inhibitor OBP-801 Promotes MHC Class I Presentation Through LMP2 Upregulation, Enhancing the PD-1-Targeting Therapy in Clear Cell Renal Cell Carcinoma

BACKGROUND

Histone deacetylase (HDAC) inhibitors have been reported to exhibit immunomodulatory activities, including the upregulation of major histocompatibility complex class I (MHC class I). Although the immunoproteasome plays a pivotal role in MHC class I antigen presentation, its effect on immunotherapy for clear cell renal cell carcinoma (ccRCC) remains unclear.

METHODS

This study assessed whether OBP-801, a novel HDAC inhibitor, affects the expression of immunoproteasome subunits and subsequently the MHC class-I-mediated anti-cancer immunity in ccRCC. We analyzed the data of 531 patients with ccRCC from the Cancer Genome Atlas Kidney Clear Cell Carcinoma database. We further evaluated the treatment efficacy of the combination of OBP-801 and anti-PD-1 in a ccRCC mouse model.

RESULTS

Low molecular mass polypeptide (LMP) 2 was correlated most positively with CD3E, CD8A, and CD8B expression and estimated CD8+ T cell number. In vitro studies showed that OBP-801 upregulated MHC class I presentation by inducing LMP2 expression in the ccRCC cell lines RENCA, 786-O, and Caki-1. In vivo studies in a syngeneic mouse model with subcutaneous implantation of RENCA cells showed that OBP-801 treatment increased the percentage of CD45+CD3e+ T cells in tumor-infiltrating lymphocytes. The combination of anti-PD-1 antibody and OBP-801 enhanced the anti-tumor effect, LMP2 protein expression, and MHC class I presentation in tumor cells. MHC class I presentation in the tumors of each mouse was positively correlated with the percentage of CD45+CD3e+ T cells.

CONCLUSIONS

Our results demonstrate that OBP-801 promotes MHC class I presentation through LMP2 upregulation in tumor cells and thereby potentiates PD-1-targeting therapy. These data suggest that the combination of OBP-801 and anti-PD-1 treatment is a promising therapeutic strategy for ccRCC.

CD155 Expression in Early-Stage Lung Adenocarcinoma

BACKGROUND

Cluster of differentiation (CD) 155 is a transmembrane protein that belongs to the nectin-like molecule family, which is widely overexpressed in several types of cancer. However, the clinical significance of CD155 in pathologic stage I lung adenocarcinoma remains poorly understood.

METHODS

We analyzed 320 patients diagnosed with pathologic stage I lung adenocarcinoma who underwent surgical treatment at Kyushu University Hospital between 2006 and 2015. The number of tumor cells expressing CD155 was assessed by immunohistochemistry, and patients were categorized into high and low CD155 expression groups. We compared the clinical and pathologic characteristics and clinical outcomes between these groups.

RESULTS

Mutation status of the epidermal growth factor receptor gene (EGFR) was determined in 237 patients. A total of 106 patients (33.1%) had EGFR wild-type, and 131 patients (40.9%) had EGFR mutant-type. CD155 expression was classified as high in 77 patients (24.1%) and as low in 243 (75.9%) as low. Multivariate analysis identified pleural invasion and EGFR wild-type as independent predictors of high CD155 expression. The Kaplan-Meier plot demonstrated significantly poorer recurrence-free survival and overall survival in the high CD155 group compared with the low CD155 group. Multivariate analysis showed high CD155 expression was an independent poor prognostic factor for recurrence-free and overall survival. Subgroup analyses revealed that a prognostic difference related to CD155 expression was observed only in patients with EGFR wild-type but not in those with EGFR mutant-type.

CONCLUSIONS

Our findings suggest that high expression of CD155 is associated with EGFR wild-type and could serve as a valuable prognostic marker in pathologic stage I lung adenocarcinoma, particularly in cases without EGFR mutation.

The role of programmed death receptor (PD-)1/PD-ligand (L)1 in periodontitis and cancer

The programmed-death-ligand-1 (PD-L1) is an immune-modulating molecule that is constitutively expressed on various immune cells, different epithelial cells and a multitude of cancer cells. It is a costimulatory molecule that may impair T-cell mediated immune response. Ligation to the programmed-death-receptor (PD)-1, on activated T-cells and further triggering of the related signaling pathways can induce T-cells apoptosis or anergy. The upregulation of PD-L1 in various cancer types, including oral squamous cell carcinomas, was demonstrated and has been linked to immune escape of tumors and poor prognosis. A bidirectional relationship exists between the increased PD-L1 expression and periodontitis as well as the epithelial-mesenchymal transition (EMT), a process of interconversion of epithelial cells to mesenchymal cells that may induce immune escape of tumors. Interaction between exosomal PD-L1 and PD-1 on T-cells may cause immunosuppression by blocking the activation and proliferation of T-cells. The efficacy and importance of treatment with PD-1/PD-L1 checkpoint inhibitors and their prognostic influence on human cancers was demonstrated. Regarding PD-1/PD-L1 checkpoint inhibitors, resistances exist or may develop, basing on various factors. Further investigations of the underlying mechanisms will help to overcome the therapeutic limitations that result from resistances and to develop new strategies for the treatment of cancer.

Tumor eradication by triplet therapy with BRAF inhibitor, TLR 7 agonist, and PD-1 antibody for BRAF-mutated melanoma

Programmed death 1 (PD-1)/programmed death-ligand 1 inhibitors are commonly used to treat various cancers, including melanoma. However, their efficacy as monotherapy is limited, and combination immunotherapies are being explored to improve outcomes. In this study, we investigated a combination immunotherapy involving an anti-PD-1 antibody that blocks the major adaptive immune-resistant mechanisms, a BRAF inhibitor that inhibits melanoma cell proliferation, and multiple primary immune-resistant mechanisms, such as cancer cell-derived immunosuppressive cytokines, and a Toll-like receptor 7 agonist that enhances innate immune responses that promote antitumor T-cell induction and functions. Using a xenogeneic nude mouse model implanted with human BRAF-mutated melanoma, a BRAF inhibitor vemurafenib was found to restore T-cell-stimulatory activity in conventional dendritic cells by reducing immunosuppressive cytokines, including interleukin 6, produced by human melanoma. Additionally, intravenous administration of the Toll-like receptor 7 agonist DSR6434 enhanced tumor growth inhibition by vemurafenib through stimulating the plasmacytoid dendritic cells/interferon-α/natural killer cell pathways and augmenting the T-cell-stimulatory activity of conventional dendritic cells. In a syngeneic mouse model implanted with murine BRAF-mutated melanoma, the vemurafenib and DSR6434 combination synergistically augmented the induction of melanoma antigen gp100-specific T cells and inhibited tumor growth. Notably, only triplet therapy with vemurafenib, DSR6434, and the anti-PD-1 antibody resulted in complete regression of SIY antigen-transduced BRAF-mutated melanoma in a CD8 T-cell-dependent manner. These findings indicate that a triple-combination strategy targeting adaptive and primary resistant mechanisms while enhancing innate immune responses that promote tumor-specific T cells may be crucial for effective tumor eradication.

Utility of neutrophil-to-lymphocyte ratio as an indicator of tumor immune status in non-small cell lung cancer

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) has been reported as a prognostic biomarker in non-small cell lung cancer (NSCLC); however, the underlying biological rationale remains unclear. The present study aimed to explore the potential utility of NLR as a surrogate biomarker for immune response to cancer and to elucidate the underlying mechanism.

METHODS

This retrospective study included the medical records of 120 patients with NSCLC who underwent surgery at the study institution in 2012. NLR in peripheral blood was determined from blood test within 30 days before surgery. Tumor immune status was evaluated using immunohistochemical staining to identify CD3+, CD8+ and FOXP3+ tumor-infiltrating lymphocytes (TILs), and the relationship of NLR, with clinicopathologic characteristics including 5-year overall survival (OS), and the tumor immune status was investigated. The median values of NLR and TIL count were used as cutoff points.

RESULTS

The 5-year OS was significantly better in patients with low NLR (<2.2) than in those with high NLR (≥2.2) (70.1% vs. 56.8%, P = 0.042) and in patients with high CD3+ TIL count (≥242) than in those with low CD3+ TIL count (<242) (70% vs. 56.8%, P = 0.019). Additionally, the CD3+ TIL count was negatively correlated with preoperative NLR (P = 0.005).

CONCLUSION

NLR might potentially reflect the immune status of tumor microenvironment, explaining its impact on prognosis of patients with NSCLC.

Pt-Te-Nanorod-Based Photothermal Chemokine Immunotherapy for All Stages of Cancer via Adaptive and Innate Immunity

The chemokine (C-X-C) motif ligand 9 (CXCL9) is one of the lymphocyte-traffic-involved chemokines. Despite the immunotherapeutic potential of CXCL9 for recruiting effector T cells (cluster of differentiation 4+ (CD4+) and CD8+ T cells) and natural killer cells (NK cells) around the tumors, practical applications of CXCL9 have been limited because of its immune toxicity and lack of stability in vivo. To overcome these limitations, we designed and synthesized Pt-Te nanorods (PtTeNRs), which exhibited excellent photothermal conversion efficiency with stable CXCL9 payload characteristics under the physiological conditions of in vivo environments. We developed a CXCL9-based immunotherapy strategy by utilizing the unique physicochemical properties of developed PtTeNRs. The investigation revealed that the PtTeNR-loaded CXCL9 was effectively accumulated in the tumor, subsequently released in a sustained manner, and successfully recruited effector T cells for immunotherapy of the designated tumor tissue. In addition, a synergistic effect was observed between the photothermal (PT) therapy and antiprogrammed cell death protein 1 (aPD-1) antibody. In this study, we demonstrated that PtTeNR-based CXCL9, PT, and aPD-1 antibody trimodal therapy delivers an outstanding tumor suppression effect in all stages of cancer, including phases 1-4 and tumor recurrence.

Advancing non-small cell lung cancer treatment: the power of combination immunotherapies

Non-small cell lung cancer (NSCLC) remains an unsolved challenge in oncology, signifying a substantial global health burden. While considerable progress has been made in recent years through the emergence of immunotherapy modalities, such as immune checkpoint inhibitors (ICIs), monotherapies often yield limited clinical outcomes. The rationale behind combining various immunotherapeutic or other anticancer agents, the mechanistic underpinnings, and the clinical evidence supporting their utilization is crucial in NSCLC therapy. Regarding the synergistic potential of combination immunotherapies, this study aims to provide insights to help the landscape of NSCLC treatment and improve clinical outcomes. In addition, this review article discusses the challenges and considerations of combination regimens, including toxicity management and patient selection.

Further knowledge and developments in resistance mechanisms to immune checkpoint inhibitors

The past decade has witnessed a revolution in cancer treatment, shifting from conventional drugs (chemotherapies) towards targeted molecular therapies and immune-based therapies, in particular immune-checkpoint inhibitors (ICIs). These immunotherapies release the host's immune system against the tumor and have shown unprecedented durable remission for patients with cancers that were thought incurable, such as metastatic melanoma, metastatic renal cell carcinoma (RCC), microsatellite instability (MSI) high colorectal cancer and late stages of non-small cell lung cancer (NSCLC). However, about 80% of the patients fail to respond to these immunotherapies and are therefore left with other less effective and potentially toxic treatments. Identifying and understanding the mechanisms that enable cancerous cells to adapt to and eventually overcome therapy can help circumvent resistance and improve treatment. In this review, we describe the recent discoveries on the onco-immunological processes which govern the tumor microenvironment and their impact on the resistance to PD-1/PD-L1 checkpoint blockade.

Improving combination cancer immunotherapy by manipulating dual immunomodulatory signals with enzyme-triggered, cell-penetrating peptide-mediated biomodulators

Immunosuppressive tumor microenvironments challenge the effectiveness of protein-based biopharmaceuticals in cancer immunotherapy. Reestablishing tumor cell immunogenicity by enhancing calreticulin (CRT) exposure is expected to improve tumor immunotherapy. Given that CRT translocation is inherently modulated by phosphorylated eIF2α, the selective inhibition of protein phosphatase 1 (PP1) emerges as an effective strategy to augment tumor immunogenicity. To harness the PP1-disrupting potential of GADD34-derived motifs and address their limited intracellular delivery, we integrated these sequences into an enzyme-triggered, cell-penetrating peptide-mediated chimeric protein scaffold. This design not only facilitates efficient cytoplasmic delivery of these immunostimulatory motifs to induce "eat-me" signaling, but also provides a versatile platform for combination immunotherapy. Fabrication of biomodulators with cytotoxic BLF1 provides additional "eat-me" signaling through phosphatidylserine exposure or that with an immunomodulatory designed ankyrin repeat protein disables "don't-find-me" signaling by antagonizing PD-L1. Notably, these bifunctional biomodulators exhibit remarkable ability to induce macrophage phagocytosis, dendritic cell maturation, and CD8+ T activation, ultimately substantially inhibiting tumor growth. This study presents a modular genetic coding strategy for PP1-centered therapies that enables seamless integration of immunostimulatory sequences into protein-based anti-tumor cocktail therapies, thereby offering novel alternatives for improving antitumor efficacy.

A Vaccine against Cancer: Can There Be a Possible Strategy to Face the Challenge? Possible Targets and Paradoxical Effects

Is it possible to have an available vaccine that eradicates cancer? Starting from this question, this article tries to verify the state of the art, proposing a different approach to the issue. The variety of cancers and different and often unknown causes of cancer impede, except in some cited cases, the creation of a classical vaccine directed at the causative agent. The efforts of the scientific community are oriented toward stimulating the immune systems of patients, thereby preventing immune evasion, and heightening chemotherapeutic agents effects against cancer. However, the results are not decisive, because without any warning signs, metastasis often occurs. The purpose of this paper is to elaborate on a vaccine that must be administered to a patient in order to prevent metastasis; metastasis is an event that leads to death, and thus, preventing it could transform cancer into a chronic disease. We underline the fact that the field has not been studied in depth, and that the complexity of metastatic processes should not be underestimated. Then, with the aim of identifying the target of a cancer vaccine, we draw attention to the presence of the paradoxical actions of different mechanisms, pathways, molecules, and immune and non-immune cells characteristic of the tumor microenvironment at the primary site and pre-metastatic niche in order to exclude possible vaccine candidates that have opposite effects/behaviors; after a meticulous evaluation, we propose possible targets to develop a metastasis-targeting vaccine. We conclude that a change in the current concept of a cancer vaccine is needed, and the efforts of the scientific community should be redirected toward a metastasis-targeting vaccine, with the increasing hope of eradicating cancer.

MicroRNA-326 negatively regulates CD155 expression in lung adenocarcinoma

Treatment with immune checkpoint inhibitors induces a durable response in some patients with non-small-cell lung cancer, but eventually gives rise to drug resistance. Upregulation of CD155 expression is implicated as one mechanism of resistance to programmed death receptor-1 (PD-1)/PD-1 ligand (PD-L1) inhibitors, and it is therefore important to characterize the mechanisms underlying regulation of CD155 expression in tumor cells. The aim of this study was to identify microRNAs (miRNAs) that might regulate CD155 expression at the posttranscriptional level in lung cancer. Comprehensive miRNA screening with target prediction programs and a dual-luciferase reporter assay identified miR-346, miR-328-3p, miR-326, and miR-330-5p as miRNAs that bind to the 3'-UTR of CD155 mRNA. Forced expression of these miRNAs suppressed CD155 expression in lung cancer cell lines. Immunohistochemical staining of CD155 in tissue specimens from 57 patients with lung adenocarcinoma revealed the median tumor proportion score for CD155 to be 68%. The abundance of miR-326 in these specimens with a low level of CD155 expression was significantly greater than in specimens with a high level (p < 0.005). Our results thus suggest that miR-326 negatively regulates CD155 expression in lung adenocarcinoma and might therefore play a role in the development of resistance to PD-1/PD-L1 inhibitors.

Regulatory miRNAs and lncRNAs in Skin Cancer: A Narrative Review

Non-coding RNAs (ncRNAs) have a significant regulatory role in the pathogenesis of skin cancer, despite the fact that protein-coding genes have generally been the focus of research efforts in the field. We comment on the actions of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in the current review with an eye toward potential therapeutic treatments. LncRNAs are remarkably adaptable, acting as scaffolding, guides, or decoys to modify key signaling pathways (i.e., the Wnt/β-catenin pathway) and gene expression. As post-transcriptional gatekeepers, miRNAs control gene expression by attaching to messenger RNAs and causing their degradation or suppression during translation. Cell cycle regulation, cellular differentiation, and immunological responses are all affected by the dysregulation of miRNAs observed in skin cancer. NcRNAs also show promise as diagnostic biomarkers and prognostic indicators. Unraveling the complexity of the regulatory networks governed by ncRNAs in skin cancer offers unprecedented opportunities for groundbreaking targeted therapies, revolutionizing the landscape of dermatologic care.

Comprehensive analyses of genome-wide methylation and RNA epigenetics identify prognostic biomarkers, regulating the tumor immune microenvironment in lung adenocarcinoma

The aim of our study was to identify a signature of immune-regulated molecules and reveal its prognostic role in lung adenocarcinoma (LUAD). We downloaded RNA-Sequencing data and DNA methylation data from the Gene Expression Omnibus (GEO) database. GEO2R was used to analyze differentially expressed mRNAs (DEmRNAs). we used "factoextra" R package to do the principal component analysis (PCA) of DEmRNAs. "Limma" R package was used to identify DEmRNAs, differentially expressed miRNAs (DEmiRNAs), differentially expressed lncRNAs (DElncRNAs) from The Cancer Genome Atlas (TCGA) database. Three R packages "org.Hs.eg.db", "clusterProfiler", "ggplot2″ were used to show enrichment results. Considering about methylation and mutation data, TEK and SOX17 mediated cancer signaling pathways. Through tumor-immune system interactions database (TISIDB) and Tumor Immune Estimation Resource (TIMER), higher methylated and lower expressed TEK may act as a prognostic marker, regulating the tumor immunity in LUAD. Through four databases (MEXPRESS, DNMIVD, MethSurv, Firehose), we further verified the methylation (P = 2.33e-23) and mutation about TEK. A signature of immune-associated TEK to predict survival of LUAD patients was validated. Prognostic, methylation, immune microenvironment analysis showed new light on potential novel therapeutic targets in LUAD.

Orchestrating smart therapeutics to achieve optimal treatment in small cell lung cancer: recent progress and future directions

Small cell lung cancer (SCLC) is a recalcitrant malignancy with elusive mechanism of pathogenesis and dismal prognosis. Over the past decades, platinum-based chemotherapy has been the backbone treatment for SCLC. However, subsequent chemoresistance after initial effectiveness urges researchers to explore novel therapeutic targets of SCLC. Recent years have witnessed significant improvements in targeted therapy in SCLC. New molecular candidates such as Ataxia telangiectasia and RAD3-related protein (ATR), WEE1, checkpoint kinase 1 (CHK1) and poly-ADP-ribose polymerase (PARP) have shown promising therapeutic utility in SCLC. While immune checkpoint inhibitor (ICI) has emerged as an indispensable treatment modality for SCLC, approaches to boost efficacy and reduce toxicity as well as selection of reliable biomarkers for ICI in SCLC have remained elusive and warrants our further investigation. Given the increasing importance of precision medicine in SCLC, optimal subtyping of SCLC using multi-omics have gradually applied into clinical practice, which may identify more drug targets and better tailor treatment strategies to each individual patient. The present review summarizes recent progress and future directions in SCLC. In addition to the emerging new therapeutics, we also focus on the establishment of predictive model for early detection of SCLC. More importantly, we also propose a multi-dimensional model in the prognosis of SCLC to ultimately attain the goal of accurate treatment of SCLC.

Research progress of biomarkers in the prediction of anti-PD-1/PD-L1 immunotherapeutic efficiency in lung cancer

Currently, anti-PD-1/PD-L1 immunotherapy using immune checkpoint inhibitors is widely used in the treatment of multiple cancer types including lung cancer, which is a leading cause of cancer death in the world. However, only a limited proportion of lung cancer patients will benefit from anti-PD-1/PD-L1 therapy. Therefore, it is of importance to predict the response to immunotherapy for the precision treatment of patients. Although the expression of PD-L1 and tumor mutation burden (TMB) are commonly used to predict the clinical response of anti-PD-1/PD-L1 therapy, other factors such as tumor-specific genes, dMMR/MSI, and gut microbiome are also promising predictors for immunotherapy in lung cancer. Furthermore, invasive peripheral blood biomarkers including blood DNA-related biomarkers (e.g., ctDNA and bTMB), blood cell-related biomarkers (e.g., immune cells and TCR), and other blood-related biomarkers (e.g., soluble PD-L1 and cytokines) were utilized to predict the immunotherapeutic response. In this review, the current achievements of anti-PD-1/PD-L1 therapy and the potential biomarkers for the prediction of anti-PD-1/PD-L1 immunotherapy in lung cancer treatment were summarized and discussed.

Melanoma antigens recognized by T cells and their use for immunotherapy

Melanoma has been a prototype for cancer immunology research, and the mechanisms of anti-tumor T-cell responses have been extensively investigated in patients treated with various immunotherapies. Individual differences in cancer-immune status are defined mainly by cancer cell characteristics such as DNA mutations generating immunogenic neo-antigens, and oncogene activation causing immunosuppression, but also by patients' genetic backgrounds such as HLA types and genetic polymorphisms of immune related molecules, and environmental and lifestyle factors such as UV rays, smoking, gut microbiota and concomitant medications; these factors have an influence on the efficacy of immunotherapy. Recent comparative studies on responders and non-responders in immune-checkpoint inhibitor therapy using various new technologies including multi-omics analyses on genomic DNA, mRNA, metabolites and microbiota and single cell analyses of various immune cells have led to the advance of human tumor immunology and the development of new immunotherapy. Based on the new findings from these investigations, personalized cancer immunotherapies along with appropriate biomarkers and therapeutic targets are being developed for patients with melanoma. Here, we will discuss one of the essential subjects in tumor immunology: identification of immunogenic tumor antigens and their effective use in various immunotherapies including cancer vaccines and adoptive T-cell therapy.

Resistance to immune checkpoint inhibitors and the tumor microenvironment

Immune checkpoint inhibitors (ICIs) have contributed significantly to the treatment of various types of cancer, including skin cancer. However, not all patients respond; some patients do not respond at all (primary resistance), while others experience recurrence after the initial response (acquired resistance). Therefore, overcoming ICI resistance is an urgent priority. Numerous ICI resistance mechanisms have been reported. They are seemingly quite complex, varying from patient to patient. However, most involve T-cell activation processes, especially in the tumor microenvironment (TME). ICIs exert their effects in the TME by reactivating suppressed T cells through inhibition of immune checkpoint molecules, such as cytotoxic T-lymphocyte antigen-4 (CTLA-4) and programmed cell death protein 1 (PD-1). Thus, this review focuses on the resistance mechanisms based on the T-cell activation process. Here, we classify the main mechanisms of ICI resistance into three categories based on (1) antigen recognition, (2) T-cell migration and infiltration, and (3) effector functions of T cells. By identifying and understanding these resistance mechanisms individually, including unknown mechanisms, we seek to contribute to the development of novel treatments to overcome ICI resistance.

lncRNA-mediated ceRNA network in bladder cancer

Bladder cancer is a common disease associated with high rates of morbidity and mortality. Although immunotherapy approaches such as adoptive T-cell therapy and immune checkpoint blockade have been investigated for the treatment of bladder cancer, their off-target effects and ability to affect only single targets have led to clinical outcomes that are far from satisfactory. Therefore, it is important to identify novel targets that can effectively control tumor growth and metastasis. It is well known that long noncoding RNAs (lncRNAs) are powerful regulators of gene expression. Increasing evidence has shown that dysregulated lncRNAs in bladder cancer are involved in cancer cell proliferation, migration, invasion, apoptosis, and epithelial-mesenchymal transition (EMT). In this review, we focus on the roles and underlying mechanisms of lncRNA-mediated competing endogenous RNA (ceRNA) networks in the regulation of bladder cancer progression. In addition, we discuss the potential of targeting lncRNA-mediated ceRNA networks to overcome cancer treatment resistance and its association with clinicopathological features and outcomes in bladder cancer patients. We hope this review will stimulate research to develop more effective therapeutic approaches for bladder cancer treatment.

Mechanisms of resistance to immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) are effective for various types of cancer, and their application has led to paradigm shifts in cancer treatment. While many patients can obtain clinical benefits from ICI treatment, a large number of patients are primarily resistant to such treatment or acquire resistance after an initial response. Thus, elucidating the resistance mechanisms is warranted to improve the clinical outcomes of ICI treatment. ICIs exert their antitumor effects by activating T cells in the tumor microenvironment. There are various resistance mechanisms, such as insufficient antigen recognition by T cells, impaired T-cell migration and/or infiltration, and reduced T-cell cytotoxicity, most of which are related to the T-cell activation process. Thus, we classify them into three main mechanisms: resistance mechanisms related to antigen recognition, T-cell migration and/or infiltration, and effector functions of T cells. In this review, we summarize these mechanisms of resistance to ICIs related to the T-cell activation process and progress in the development of novel therapies that can overcome resistance.

Interactome battling of lncRNA CCDC144NL-AS1: Its role in the emergence and ferocity of cancer and beyond

Long non-coding RNAs (lncRNAs) were, once, viewed as "noise" for transcription. Recently, many lncRNAs are functionally linked to several human disorders, including cancer. Coiled-Coil Domain Containing 144 N-Terminal-Like antisense1 (CCDC144NL-AS1) is a newly discovered cytosolic lncRNA. Aberrant CCDC144NL-AS1 expression was discovered in hepatocellular carcinoma (HCC), ovarian cancer (OC), gastric cancer (GC), non-small cell lung cancer (NSCLC), and osteosarcoma. CCDC144NL-AS1 could be a promising prognostic biological marker and therapeutic target for cancer. In this review, we will collect and highlight the available information about CCDC144NL-AS1 role in various cancers. Moreover, we will discuss the diagnostic and prognostic utility of CCDC144NL-AS1 as a new molecular biomarker for several human malignancies, besides its potential therapeutic importance.

The role of PD-1/PD-L1 and application of immune-checkpoint inhibitors in human cancers

Programmed cell death protein-1 (PD-1) is a checkpoint receptor expressed on the surface of various immune cells. PD-L1, the natural receptor for PD-1, is mainly expressed in tumor cells. Studies have indicated that PD-1 and PD-L1 are closely associated with the progression of human cancers and are promising biomarkers for cancer therapy. Moreover, the interaction of PD-1 and PD-L1 is one of the important mechanism by which human tumors generate immune escape. This article provides a review on the role of PD-L1/PD-1, mechanisms of immune response and resistance, as well as immune-related adverse events in the treatment of anti-PD-1/PD-L1 immunotherapy in human cancers. Moreover, we summarized a large number of clinical trials to successfully reveal that PD-1/PD-L1 Immune-checkpoint inhibitors have manifested promising therapeutic effects, which have been evaluated from different perspectives, including overall survival, objective effective rate and medium progression-free survival. Finally, we pointed out the current problems faced by PD-1/PD-L1 Immune-checkpoint inhibitors and its future prospects. Although PD-1/PD-L1 immune checkpoint inhibitors have been widely used in the treatment of human cancers, tough challenges still remain. Combination therapy and predictive models based on integrated biomarker determination theory may be the future directions for the application of PD-1/PD-L1 Immune-checkpoint inhibitors in treating human cancers.

Immune Cells in Hyperprogressive Disease under Immune Checkpoint-Based Immunotherapy

Immunotherapy, an antitumor therapy designed to activate antitumor immune responses to eliminate tumor cells, has been deeply studied and widely applied in recent years. Immune checkpoint inhibitors (ICIs) are capable of preventing the immune responses from being turned off before tumor cells are eliminated. ICIs have been demonstrated to be one of the most effective and promising tumor treatments and significantly improve the survival of patients with multiple tumor types. However, low effective rates and frequent atypical responses observed in clinical practice limit their clinical applications. Hyperprogressive disease (HPD) is an unexpected phenomenon observed in immune checkpoint-based immunotherapy and is a challenge facing clinicians and patients alike. Patients who experience HPD not only cannot benefit from immunotherapy, but also experience rapid tumor progression. However, the mechanisms of HPD remain unclear and controversial. This review summarized current findings from cell experiments, animal studies, retrospective studies, and case reports, focusing on the relationships between various immune cells and HPD and providing important insights for understanding the pathogenesis of HPD.

Oncolytic Adenoviral Vector-Mediated Expression of an Anti-PD-L1-scFv Improves Anti-Tumoral Efficacy in a Melanoma Mouse Model

Oncolytic virotherapy is an emerging therapeutic approach based on replication-competent viruses able to selectively infect and destroy cancer cells, inducing the release of tumor-associated antigens and thereby recruiting immune cells with a subsequent increase in antitumoral immune response. To increase the anticancer activity, we engineered a specific oncolytic adenovirus expressing a single-chain variable fragment of an antibody against PD-L1 to combine blockage of PD-1/PD-L1 interaction with the antitumoral activity of Onc.Ad5. To assess its efficacy, we infected B16.OVA cells, a murine model of melanoma, with Ad5Δ24 -anti-PD-L1-scFv and then co-cultured them with C57BL/6J naïve splenocytes. We observed that the combinatorial treatments were significantly more effective in inducing cancer cell death. Furthermore, we assessed the efficacy of intratumoral administrations of Ad5Δ24-anti-PD-L1-scFv in C57BL/6J mice engrafted with B16.OVA and compared this treatment to that of the parental Ad5Δ24 or placebo. Treatment with the scFv-expressing Onc.Ad induced a marked reduction of tumor growth concerning the parental Onc.Ad. Additionally, the evaluation of the lymphocytic population infiltrating the treated tumor reveals a favorable immune profile with an enhancement of the CD8+ population. These data suggest that Onc.Ad-mediated expression of immune checkpoint inhibitors increases oncolytic virotherapy efficacy and could be an effective and promising tool for cancer treatments, opening a new way into cancer therapy.

Challenges of the Immunotherapy: Perspectives and Limitations of the Immune Checkpoint Inhibitor Treatment

Immunotherapy is a quickly developing type of treatment and the future of therapy in oncology. This paper is a review of recent findings in the field of immunotherapy with an emphasis on immune checkpoint inhibitors. The challenges that immunotherapy might face in near future, such as primary and acquired resistance and the irAEs, are described in this article, as well as the perspectives such as identification of environmental modifiers of immunity and development of anti-cancer vaccines and combined therapies. There are multiple factors that may be responsible for immunoresistance, such as genomic factors, factors related to the immune system cells or to the cancer microenvironment, factors emerging from the host cells, as well as other factors such as advanced age, biological sex, diet, many hormones, existing comorbidities, and the gut microbiome.

Immune Microenvironment Characteristics of Urachal Carcinoma and Its Implications for Prognosis and Immunotherapy

Urachal carcinoma (UrC) is an exceedingly rare tumor and lacks effective treatment. Herein, we characterized an immune microenvironment characteristic of UrC in detail and identified its implications for prognosis and immunotherapy. In total, 37 resections of UrC were stained for CD20, CD3, CD4, CD8, FOXP3, CD68, HLA-DR, CD163, PD1, and PD-L1, as well as mismatch repair protein including MSH2, MSH6, MLH1, and PMS2 by immunohistochemistry. Intratumoral and peritumoral immune cell densities or the proportion of PD1 and PD-L1 expression alongside MSH2, MSH6, MLH1, and PMS2 status were manually evaluated using the whole slide. UrC patients with the number of tertiary lymphoid structures (TLS) per slide tended to be higher in tumors with dMMR (p = 0.1919), and tumors with higher number of TLS tended to have longer OS (p = 0.0940) and DFS (p = 0.0700). High densities of CD3+ T, CD8+ T, and CD68+ cells were significantly associated with worse OS and DFS (both p<0.05). Increased intratumoral (p = 0.0111) and peritumoral (p = 0.0485) CD8+ T cell densities were significantly associated with PD-L1 expression or increasing proportion of PD-L1 expression on immune cells. Similarly, increased intratumoral (p = 0.0008) and peritumoral (p = 0.063) CD8+ T cell densities were significantly associated with increasing proportion of PD1 expression on immune cells. Tumors with PD-L1 positive expression on immune cells had a significantly increased proportion of PD1 expression (p = 0.0121). High peritumoral CD8+ T cell density (>73.7/mm²) was significantly associated with worse OS (p = 0.0120) and DFS (p = 0.00095). The number of TLS seems to be considered not only as histopathological characteristics in predicting MMR status of UrC, but also as a prognostic or therapeutic biomarker, and we also provide some important suggestions for targeting PD-1/PD-L1 checkpoint in UrC.

HBI-8000, HUYABIO Lead Clinical Program, Is a Selective Histone Deacetylase Inhibitor With Therapeutic Benefits in Leukemia and in Solid Tumors

HBI-8000 is a small molecule inhibitor of class I HDACs and has been approved for the treatment of PTCL, ATL and, in combination with exemestane, in a subpopulation of breast cancer. Given the roles of HDACs in normal and cancerous cells, there are currently multiple clinical trials, by HUYABIO International, to test the efficacy of HBI-8000 in monotherapy or in combination settings in leukemias and in solid tumors. The current review is focused on the applications of HDACi HBI-8000 in cancer therapy and its potential in combination with DDR agents.

KRAS(G12D) can be targeted by potent inhibitors via formation of salt bridge

KRAS mutation occurs in nearly 30% of human cancers, yet the most prevalent and oncogenic KRAS(G12D) variant still lacks inhibitors. Herein, we designed a series of potent inhibitors that can form a salt bridge with KRAS’s Asp12 residue. Our ITC results show that these inhibitors have similar binding affinity with both GDP-bound and GTP-bound KRAS(G12D), and our crystallographic studies reveal the structural basis of inhibitor binding-induced switch-II pocket in KRAS(G12D), experimentally confirming the formation of a salt bridge between the piperazine moiety of the inhibitors and the Asp12 residue of the mutant protein. Among KRAS family proteins and mutants, both ITC and enzymatic assays demonstrate the selectivity of the inhibitors for KRAS(G12D); and the inhibitors disrupt the KRAS–CRAF interaction. We also observed the inhibition of cancer cell proliferation as well as MAPK signaling by a representative inhibitor (TH-Z835). However, since the inhibition was not fully dependent on KRAS mutation status, it is possible that our inhibitors may have off-target effects via targeting non-KRAS small GTPases. Experiments with mouse xenograft models of pancreatic cancer showed that TH-Z835 significantly reduced tumor volume and synergized with an anti-PD-1 antibody. Collectively, our study demonstrates proof-of-concept for a strategy based on salt-bridge and induced-fit pocket formation for KRAS(G12D) targeting, which warrants future medicinal chemistry efforts for optimal efficacy and minimized off-target effects.

Long Non-Coding RNAs (lncRNAs) in Response and Resistance to Cancer Immunosurveillance and Immunotherapy

Long non-coding RNAs (lncRNAs) are critical regulatory elements in cellular functions in states of both normalcy and disease, including cancer. LncRNAs can influence not only tumorigenesis but also cancer features such as metastasis, angiogenesis and resistance to chemo-and immune-mediated apoptotic signals. Several lncRNAs have been demonstrated to control directly or indirectly the number, type and activities of distinct immune cell populations of adaptive and innate immunities within and without the tumor microenvironment. The disruption of lncRNA expression in both cancer and immune cells may reflect alterations in tumor responses to cancer immunosurveillance and immunotherapy, thus providing new insights into lncRNA biomarker-based prognostic and therapeutic cancer assessment. Here we present an overview on lncRNAs’ functions and underlying molecular mechanisms related to cancer immunity and conventional immunotherapy, with the expectation that any elucidations may lead to a better understanding and management of cancer immune escape and response to current and future immunotherapeutics.

TIGIT/CD155 axis mediates resistance to immunotherapy in patients with melanoma with the inflamed tumor microenvironment

BACKGROUND

Patients with cancer benefit from treatment with immune checkpoint inhibitors (ICIs), and those with an inflamed tumor microenvironment (TME) and/or high tumor mutation burden (TMB), particularly, tend to respond to ICIs; however, some patients fail, whereas others acquire resistance after initial response despite the inflamed TME and/or high TMB. We assessed the detailed biological mechanisms of resistance to ICIs such as programmed death 1 and/or cytotoxic T-lymphocyte-associated protein 4 blockade therapies using clinical samples.

METHODS

We established four pairs of autologous tumor cell lines and tumor-infiltrating lymphocytes (TILs) from patients with melanoma treated with ICIs. These tumor cell lines and TILs were subjected to comprehensive analyses and in vitro functional assays. We assessed tumor volume and TILs in vivo mouse models to validate identified mechanism. Furthermore, we analyzed additional clinical samples from another large melanoma cohort.

RESULTS

Two patients were super-responders, and the others acquired resistance: the first patient had a non-inflamed TME and acquired resistance due to the loss of the beta-2 microglobulin gene, and the other acquired resistance despite having inflamed TME and extremely high TMB which are reportedly predictive biomarkers. Tumor cell line and paired TIL analyses showed high CD155, TIGIT ligand, and TIGIT expression in the tumor cell line and tumor-infiltrating T cells, respectively. TIGIT blockade or CD155-deletion activated T cells in a functional assay using an autologous cell line and paired TILs from this patient. CD155 expression increased in surviving tumor cells after coculturing with TILs from a responder, which suppressed TIGIT⁺ T-cell activation. Consistently, TIGIT blockade or CD155-deletion could aid in overcoming resistance to ICIs in vivo mouse models. In clinical samples, CD155 was related to resistance to ICIs in patients with melanoma with an inflamed TME, including both primary and acquired resistance.

CONCLUSIONS

The TIGIT/CD155 axis mediates resistance to ICIs in patients with melanoma with an inflamed TME, promoting the development of TIGIT blockade therapies in such patients with cancer.

Construction of a New Tumor Immunity-Related Signature to Assess and Classify the Prognostic Risk of Colorectal Cancer

Purpose

Although immunotherapy and checkpoint inhibitors contribute to the treatment of colorectal cancer (CRC), few patients can benefit from these treatments. Therefore, our goal was to develop a marker based on immune-related genes to predict the prognosis of patients with CRC to guide treatment strategies.

Methods

Gene expression data from colorectal cancer patients in the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas were analyzed systematically. We used Cox regression to identify immune-related genes with potential prognostic value. The expression of immune genes, infiltration level of immune cells, and several immune-related molecules were further compared between the high-risk and low-risk groups. Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway analyses were used for functional analysis.

Results

Five GEO datasets were integrated into a merged GEO dataset, which showed obvious survival in StromalScore and ESTIMATEScore. WGCNA showed that 749 genes of the pink module are related to immunity, 95 of which are related to prognosis, correlating with cytokine–cytokine receptor interaction and natural killer cell-mediated cytotoxicity. Among these genes, an 11-gene signature was developed through stability selection and LASSO Cox regression. Univariate and multifactorial Cox regression analyses demonstrated that gene signature was an independent prognostic factor for predicting survival in patients with colorectal cancer. Samples from the low-risk group may be more sensitive to immunotherapy. In addition, the nomogram risk prediction model effectively predicted the prognosis of CRC patients by appropriately stratifying the risk scores.

Conclusion

In conclusion, we developed a novel immune-related gene signature that may be useful in predicting cancer progression and prognosis, thus contributing to the individualized management of colorectal cancer patients.

The epigenetic immunomodulator, HBI-8000, enhances the response and reverses resistance to checkpoint inhibitors

Background

Treatment with immune checkpoint inhibitors (ICIs) targeting CTLA-4 and the PD-1/PD-L1 axis is effective against many cancer types. However, due in part to unresponsiveness or acquired resistance, not all patients experience a durable response to ICIs. HBI-8000 is a novel, orally bioavailable class I selective histone deacetylase inhibitor that directly modifies antitumor activity by inducing apoptosis, cell cycle arrest, and resensitization to apoptotic stimuli in adult T cell lymphoma patients. We hypothesized that HBI-8000 functions as an epigenetic immunomodulator to reprogram the tumor microenvironment from immunologically cold (nonresponsive) to hot (responsive).

Method

Mice bearing syngeneic tumors (MC38 and CT26 murine colon carcinoma and A20 B-cell lymphoma were treated daily with HBI-8000 (orally), alone or in combination with PD-1, PD-1 L, or CTLA-4 antibodies. MC38 tumors were also analyzed in nanoString gene expression analysis.

Results

HBI-8000 augmented the activity of ICI antibodies targeting either PD-1, PD-L1 or CTLA-4, and significantly increased tumor regression (p < 0.05) in the above models. Gene expression analysis of the treated MC38 tumors revealed significant changes in mRNA expression of immune checkpoints, with enhanced dendritic cell and antigen-presenting cell functions, and modulation of MHC class I and II molecules.

Conclusions

These findings suggest that HBI-8000 mediates epigenetic modifications in the tumor microenvironment, leading to improved efficacy of ICIs, and provide strong rationale for combination therapies with ICIs and HBI-8000 in the clinical setting.

Precis

As an HDACi, HBI-8000 plays an important role in priming the immune system in the tumor microenvironment. The current preclinical data further justifies testing combination of HBI-8000 and ICIs in the clinic.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08702-x.

Engineered hypoxia-responding Escherichia coli carrying cardiac peptide genes, suppresses tumor growth, angiogenesis and metastasis in vivo

Development of engineered non-pathogenic bacteria, capable of expressing anti-cancer proteins under tumor-specific conditions, is an ideal approach for selectively eradicating proliferating cancer cells. Herein, using an engineered hypoxia responding nirB promoter, we developed an engineered Escherichia coli BW25133 strain capable of expressing cardiac peptides and GFP signaling protein under hypoxic condition for spatiotemporal targeting of mice mammary tumors. Following determination of the in vitro cytotoxicity profile of the engineered bacteria, selective accumulation of bacteria in tumor microenvironment was studied 48 h after tail vein injection of 108 cfu bacteria in animals. For in vivo evaluation of antitumoral activities, mice with establishment mammary tumors received 3 consecutive intravenous injections of transformed bacteria with 4-day intervals and alterations in expression of tumor growth, invasion and angiogenesis specific biomarkers (Ki-67, VEGFR, CD31and MMP9 respectively), as well as fold changes in concentration of proinflammatory cytokines were examined at the end of the 24-day study period. Intravenously injected bacteria could selectively accumulate in tumor site and temporally express GFP and cardiac peptides in response to hypoxia, enhancing survival rate of tumor bearing mice, suppressing tumor growth rate and expression of MMP-9, VEGFR2, CD31 and Ki67 biomarkers. Applied engineered bacteria could also significantly reduce concentrations of IL-1β, IL-6, GC-SF, IL-12 and TNF-α proinflammatory cytokines while increasing those of IL-10, IL-17A and INF-γ. Overall, administration of hypoxia-responding E. coli bacteria, carrying cardiac peptide expression construct could effectively suppress tumor growth, angiogenesis, invasion and metastasis and enhance overall survival of mice bearing mammary tumors.

Hot or cold: Bioengineering immune contextures into in vitro patient-derived tumor models

In the past decade, immune checkpoint inhibitors (ICI) have proven to be tremendously effective for a subset of cancer patients. However, it is difficult to predict the response of individual patients and efforts are now directed at understanding the mechanisms of ICI resistance. Current models of patient tumors poorly recapitulate the immune contexture, which describe immune parameters that are associated with patient survival. In this Review, we discuss parameters that influence the induction of different immune contextures found within tumors and how engineering strategies may be leveraged to recapitulate these contextures to develop the next generation of immune-competent patient-derived in vitro models.

Gene Expression Profiling of Olfactory Neuroblastoma Helps Identify Prognostic Pathways and Define Potentially Therapeutic Targets

Simple Summary

The gene expression profile of ONB defines a group of patients with a dismal prognosis and identifies potentially targetable pathways. Better prognostic stratification may offer new tailored approaches for the treatment and follow-up of ONB. The integration of new therapeutic agents with standard surgical and RT strategies may improve the outcomes in cases with worse prognoses. Furthermore, the ontogenesis of ONB in basal and neural subtypes is mirrored by different transcriptional pathways, paving the way towards different therapeutic approaches.

Abstract

Olfactory neuroblastoma (ONB) is a rare sinonasal neoplasm with a peculiar behavior, for which limited prognostic factors are available. Herein, we investigate the transcriptional pathways altered in ONB and correlate them with pathological features and clinical outcomes. We analyze 32 ONB patients treated with curative intent at two independent institutions from 2001 to 2019 for whom there is available pathologic and clinical data. We perform gene expression profiling on primary ONB samples and carry out functional enrichment analysis to investigate the key pathways associated with disease-free survival (DFS). The median age is 53.5 years; all patients undergo surgery and a pure endoscopic approach is adopted in the majority of cases (81.2%). Most patients have advanced disease (stages III–IV, 81.2%) and 84.4% undergo adjuvant (chemo)radiotherapy. The median follow-up is 35 months; 11 (26.8%) patients relapse. Clinical characteristics (gender, stage and Hyams’ grade) are not associated with the outcomes. In contrast, TGF-beta binding, EMT, IFN-alpha response, angiogenesis, IL2-STAT5 and IL6-JAK-STAT3 signaling pathways are enriched in patients experiencing recurrence, and significantly associated with shorter DFS. Clustering of transcriptional profiles according to pathological features indicates two distinct molecular groups, defined by either cytokeratin-positive or -negative immunostaining. Definition of the characterizing ONB transcriptomic pathways may pave the way towards tailored treatment approaches.

Fas-Fas Ligand Interplay in the Periphery of Salivary Gland Carcinomas as a New Checkpoint Predictor for Disease Severity and Immunotherapy Response

Salivary gland carcinomas (SGCs) are extremely morphologically heterogeneous, and treatment options for this disease are limited. Immunotherapy with immune checkpoint inhibitors (ICIs) represents a revolutionary treatment approach. However, SGCs remain largely resistant to this therapy. An increasing body of evidence suggests that resistance to ICI therapy is modulated by the Fas (CD95)–Fas ligand (FasL, CD178) interplay between tumor cells and immune cells. In this study, we examined the Fas–FasL interplay between tumor cells and tumor-infiltrating immune cells (TIICs) in the center and periphery of SGCs from 62 patients. We found that the Fas-expressing tumor cells accumulated in the center of SGC tumors with increasing tumor stage. Furthermore, this accumulation occurred regardless of the presence of TIICs expressing high levels of FasL. On the contrary, a loss of Fas-expressing TIICs with increasing tumor stage was found in the tumor periphery, whereas FasL expression in tumor cells in the tumor periphery correlated with tumor stage. These data suggest that SGC cells are resistant to FasL-induced apoptosis by TIICs but could utilize FasL to eliminate these cells in high-stage tumors to provide resistance to immunotherapy.

Inhibition of vascular adhesion protein-1 enhances the anti-tumor effects of immune checkpoint inhibitors

Modulation of the immunosuppressive tumor microenvironment (TME) is essential for enhancing the anti‐tumor effects of immune checkpoint inhibitors (ICIs). Adhesion molecules and enzymes such as vascular adhesion protein‐1 (VAP‐1), which are expressed in some cancers and tumor vascular endothelial cells, may be involved in the generation of an immunosuppressive TME. In this study, the role of VAP‐1 in TME was investigated in 2 murine colon cancer models and human cancer cells. Intraperitoneal administration of the VAP‐1‐specific inhibitor U‐V296 inhibited murine tumor growth by enhancing IFN‐γ‐producing tumor antigen‐specific CD8⁺ T cells. U‐V296 exhibited significant synergistic anti‐tumor effects with ICIs. In the TME of mice treated with U‐V296, the expression of genes associated with M2‐like macrophages, Th2 cells (Il4, Retnla, and Irf4), angiogenesis (Pecam1), and fibrosis (Acta2, Loxl2) were significantly decreased, and the Th1/Th2 balance was increased. H₂O₂, an enzymatic product of VAP‐1, which promoted the production of IL‐4 by mouse Th2 and inhibited IFN‐γ by mouse Th1 and human tumor‐infiltrating lymphocytes, was decreased in tumors and CD31⁺ tumor vascular endothelial cells in the TMEs of mice treated with VAP‐1 inhibitor. TCGA database analysis showed that VAP‐1 expression was a negative prognostic factor in human cancers, exhibiting a significant positive correlation with IL‐4, IL4R, and IL‐13 expression and a negative correlation with IFN‐γ expression. These results indicated that VAP‐1 is involved in the immunosuppressive TMEs through H₂O₂‐associated Th2/M2 conditions and may be an attractive target for the development of combination cancer immunotherapy with ICIs.

Immune Checkpoint Molecules-Inherited Variations as Markers for Cancer Risk

In recent years, immunotherapy has been revolutionized by a new approach that works by blocking receptors called immune checkpoints (IC). These molecules play a key role in maintaining immune homeostasis, mainly by suppressing the immune response and by preventing its overactivation. Since inhibition of the immune response by IC can be used by cancer to avoid recognition and destruction by immune system, blocking them enhances the anti-tumor response. This therapeutic approach has brought spectacular clinical effects. The ICs present heterogeneous expression patterns on immune cells, which may affect the effectiveness of immunotherapy. The inherited genetic variants in regulatory regions of ICs genes can be considered as potential factors responsible for observed inter-individual differences in ICs expression levels on immune cells. Additionally, polymorphism located in exons may introduce changes to ICs amino acid sequences with potential impact on functional properties of these molecules. Since genetic variants may affect both expression and structure of ICs, they are considered as risk factors of cancer development. Inherited genetic markers such as SNPs may also be useful in stratification patients into groups which will benefit from particular immunotherapy. In this review, we have comprehensively summarized the current understanding of the relationship between inherited variations of CTLA-4, PDCD1, PD-L1, BTLA, TIM-3, and LAG-3 genes in order to select SNPs which can be used as predictive biomarkers in personalized evaluation of cancer risk development and outcomes as well as possible response to immunotherapy.

Mechanisms of hyperprogressive disease after immune checkpoint inhibitor therapy: what we (don't) know

Immune checkpoint inhibitors (ICIs) have made a breakthrough in the treatment of different types of tumors, leading to improvement in survival, even in patients with advanced cancers. Despite the good clinical results, a certain percentage of patients do not respond to this kind of immunotherapy. In addition, in a fraction of nonresponder patients, which can vary from 4 to 29% according to different studies, a paradoxical boost in tumor growth after ICI administration was observed: a completely unpredictable novel pattern of cancer progression defined as hyperprogressive disease. Since this clinical phenomenon has only been recently described, a universally accepted clinical definition is lacking, and major efforts have been made to uncover the biological bases underlying hyperprogressive disease. The lines of research pursued so far have focused their attention on the study of the immune tumor microenvironment or on the analysis of intrinsic genomic characteristics of cancer cells producing data that allowed us to formulate several hypotheses to explain this detrimental effect related to ICI therapy. The aim of this review is to summarize the most important works that, to date, provide important insights that are useful in understanding the mechanistic causes of hyperprogressive disease.

New insights into the interaction of the immune system with non-small cell lung carcinomas

The basis of current and future lung cancer immunotherapy depends mainly on our knowledge of the molecular mechanisms of interactions between cancer and immune cells (ICs), as well as on interactions occurring between the different populations of intra-tumor ICs. These interactions are very complex, as virtually all immune cell types, including macrophages, neutrophils, mast cells, natural killer (NK) cells, dendritic cells and T and B lymphocytes can infiltrate lung cancer tissues at the same time. Moreover these interactions lead to progressive emergence of an imbalance in ICs. Initially ICs have an anti-tumor effect but then induce immune tolerance and eventually tumor progression and dissemination. All the cells of innate and adaptive intra-tumor immunity engage in this progressive phenotypic switch. A majority of non-small cell lung carcinoma (NSCLC) patients do not benefit from the expected positive responses associated with current immunotherapy. Thus, there is urgent need to better understand the different roles of the associated cancer ICs. This review summarizes some of the new insights into this domain, with particular focus on: the myeloid cell population associated with tumors, the tertiary lymphoid structures (TLSs), the role of the P2 purinergic receptors (P2R) and ATP, and the new concept of the “liquid microenvironment” implying blood circulating ICs.

Avelumab and axitinib combination therapy for the treatment of advanced renal cell carcinoma

Owing to an improved understanding of the immunobiological profile of renal cell carcinoma (RCC), the past few years have ushered in significant changes in systemic therapies for advanced stage RCC. First-line treatment with single-agent tyrosine kinase inhibitors (TKI) has been virtually replaced for most patients by immunotherapy combinations. The first of such treatments was the dual immune checkpoint inhibitor combination of ipilimumab and nivolumab. More recently, the combination of an immune checkpoint inhibitor and a TKI has also moved into the first-line setting. This review summarizes the pharmacologic properties, evidence for use and safety of avelumab, a PD-L1 inhibitor and axitinib a small-molecule TKI, each as monotherapy, and in combination for the management of metastatic RCC.

The humanized mouse: Emerging translational potential

The humanized mouse (HM) has emerged as a valuable animal model in cancer research. Engrafted with components of a human immune system and subsequently implanted with tumor tissue from cell lines or in the form of patient-derived xenografts, the HM provides a unique platform in which the tumor microenvironment (TME) can be evaluated in vivo. This model may also be beneficial in the assessment of potential cancer treatments including immune checkpoint inhibitors. However, to maximize its utility, researchers need to understand the critical factors necessary to ensure that the tumor immune interactions in the HM are representative of those within cancer patients. In most current HM models, the human T cells residing in the HM are educated in a murine thymus, allogeneic to implanted tumor tissue, and/or alloreactive to mouse tissues, making their interaction and reactivity with tumor cells suspect. There are several strategies underway to harmonize the immune-tumor environment in the HM. Once the essential components of the HM-tumor TME interface have been identified and understood, the HM model will permit not only the discovery of effective immunotherapy treatments, but it can be used to predict patient responses to great clinical benefit.