Mannan-Decorated Lipid Calcium Phosphate Nanoparticle Vaccine Increased the Antitumor Immune Response by Modulating the Tumor Microenvironment.

With the rapid development of tumor immunotherapy, nanoparticle vaccines have attracted much attention as potential therapeutic strategies. A systematic review and analysis must be carried out to investigate the effect of mannose modification on the immune response to nanoparticles in regulating the tumor microenvironment, as well as to explore its potential clinical application in tumor therapy. Despite the potential advantages of nanoparticle vaccines in immunotherapy, achieving an effective immune response in the tumor microenvironment remains a challenge. Tumor immune escape and the overexpression of immunosuppressive factors limit its clinical application. Therefore, our review explored how to intervene in the immunosuppressive mechanism in the tumor microenvironment through the use of mannan-decorated lipid calcium phosphate nanoparticle vaccines to improve the efficacy of immunotherapy in patients with tumors and to provide new ideas and strategies for the field of tumor therapy.

Tartrolon D induces immunogenic cell death in melanoma.

Tartrolon D (TRL) is produced by Teredinibacter turnerae, a symbiotic cellulose-degrading bacteria in shipworm gills. Immunogenic cell death (ICD) induction contributes to a better and longer-lasting response to anticancer treatment. Tumor cells undergoing ICD trigger activation of the immune system, as a vaccine. AIMS: This study aimed to evaluate ICD induction by TRL. MAIN METHODS: Cell viability was evaluated by SRB assay. Cell stress, cell death, ICD features and antigen-presenting molecules were evaluated by flow cytometry and immunoblot. KEY FINDINGS: TRL showed antiproliferative activity on 7 tumor cell lines (L929, HCT 116, B16-F10, WM293A, SK-MEL-28, PC-3M, and MCF-7) and a non-tumor cell (HEK293A), with an inhibition concentration mean (IC50) ranging from 0.03 µM to 13 µM. Metastatic melanomas, SK-MEL-28, B16-F10, and WM293A, were more sensitive cell lines, with IC50 ranging from 0.07 to 1.2 µM. TRL induced apoptosis along with autophagy and endoplasmic reticulum stress and release of typical damage-associated molecular patterns (DAMPs) of ICD such calreticulin, ERp57, and HSP70 exposure, and HMGB1 release. Additionally, melanoma B16-F10 exposed to TRL increased expression of antigen-presenting molecules MHC II and CD1d and induced activation of splenocytes of C57BL/6 mice. SIGNIFICANCE: In spite of recent advances provided by target therapy and immunotherapy, advanced metastatic melanoma is incurable for more than half of patients. ICD inducers yield better and long-lasting responses to anticancer treatment. Our findings shed light on an anticancer candidate of marine origin that induces ICD in melanoma.

Temperature-sensitive nanogels combined with polyphosphate and cisplatin for the enhancement of tumor artery embolization by coagulation activation.

Transcatheter arterial chemoembolization (TACE) is the first-line therapy for hepatocellular carcinoma (HCC). However, the exacerbated hypoxia microenvironment induces tumor relapse and metastasis post-TACE. Here, temperature-sensitive block polymer complexed with polyphosphate-cisplatin (Pt-P@PND) was prepared for the enhancement of tumor artery embolization by coagulation activation. After supra-selective infusion into the tumor vessels, Pt-P@PND nanogels performed efficient embolization of tumor arteries by sol-gel transition at body temperature. Meanwhile, coagulation cascade was evoked to form blood clots in the peripheral arteries inaccessible to the nanogels by released PolyP. The blood clots-filled hydrogel networks composed of gel and clots showed a denser structure and higher modulus, thereby achieving long-term embolization of all levels of tumor arteries. Pt-P@PND nanogels efficiently inhibited tumor growth and reduced the expression of HIF-1α, VEGF, CD31, and MMP-9 on VX2 tumor-bearing rabbit model. The released Nitro-Pt stimulated the immunogenic cell death of tumor cells, thus enhancing the antitumor immune response to suppress tumor relapse and metastasis post-TACE. It is hoped that Pt-P@PND nanogels can be developed as a promising embolic agent with procoagulant activity for enhancing the antitumor immune response through a combination of embolism, coagulation, and chemotherapy. STATEMENT OF SIGNIFICANCE: Clinical embolic agents, such as Lipiodol and polyvinyl alcohol (PVA) microspheres, are limited by their rapid elimination or larger size, thus lead to incomplete embolization of trans-catheter arterial chemoembolization (TACE). Herein, temperature-sensitive Pt-P@PND nanogels were developed to achieve long-term embolization of all levels of tumor arteries by gel/clot generation. The released Nitro-Pt induced immunogenic cell death in tumor cells, which improved the antitumor immune microenvironment by the maturation of DCs and lymphocytic infiltration. Pt-P@PND nanogels successfully inhibited tumor growth and activated an antitumor immune response to curb the recurrence and metastasis of residual tumor cells both in VX2 tumor-bearing rabbit model and 4T1 tumor-bearing mouse model. These findings suggested that Pt-P@PND could be developed as an ideal embolic agent for clinical TACE treatment.

TMPRSS2 is a tumor suppressor and its downregulation promotes antitumor immunity and immunotherapy response in lung adenocarcinoma.

BACKGROUND: TMPRSS2, a key molecule for SARS-CoV-2 invading human host cells, has an association with cancer. However, its association with lung cancer remains insufficiently unexplored. METHODS: In five bulk transcriptomics datasets, one single-cell RNA sequencing (scRNA-seq) dataset and one proteomics dataset for lung adenocarcinoma (LUAD), we explored associations between TMPRSS2 expression and immune signatures, tumor progression phenotypes, genomic features, and clinical prognosis in LUAD by the bioinformatics approach. Furthermore, we performed experimental validation of the bioinformatics findings. RESULTS: TMPRSS2 expression levels correlated negatively with the enrichment levels of both immune-stimulatory and immune-inhibitory signatures, while they correlated positively with the ratios of immune-stimulatory/immune-inhibitory signatures. It indicated that TMPRSS2 levels had a stronger negative correlation with immune-inhibitory than with immune-stimulatory signatures. TMPRSS2 downregulation correlated with increased proliferation, stemness, genomic instability, tumor progression, and worse survival in LUAD. We further validated that TMPRSS2 was downregulated with tumor progression in the LUAD cohort we collected from Jiangsu Cancer Hospital, China. In vitro and in vivo experiments verified the association of TMPRSS2 deficiency with increased tumor cell proliferation and invasion and antitumor immunity in LUAD. Moreover, in vivo experiments demonstrated that TMPRSS2-knockdown tumors were more sensitive to BMS-1, an inhibitor of PD-1/PD-L1. CONCLUSIONS: TMPRSS2 is a tumor suppressor, while its downregulation is a positive biomarker of immunotherapy in LUAD. Our data provide a potential link between lung cancer and pneumonia caused by SARS-CoV-2 infection.

Potential Benefits of Combining Proton or Carbon Ion Therapy with DNA Damage Repair Inhibitors.

The use of charged particle radiotherapy is currently increasing, but combination therapy with DNA repair inhibitors remains to be exploited in the clinic. The high-linear energy transfer (LET) radiation delivered by charged particles causes clustered DNA damage, which is particularly effective in destroying cancer cells. Whether the DNA damage response to this type of damage is different from that elicited in response to low-LET radiation, and if and how it can be targeted to increase treatment efficacy, is not fully understood. Although several preclinical studies have reported radiosensitizing effects when proton or carbon ion irradiation is combined with inhibitors of, e.g., PARP, ATR, ATM, or DNA-PKcs, further exploration is required to determine the most effective treatments. Here, we examine what is known about repair pathway choice in response to high- versus low-LET irradiation, and we discuss the effects of inhibitors of these pathways when combined with protons and carbon ions. Additionally, we explore the potential effects of DNA repair inhibitors on antitumor immune signaling upon proton and carbon ion irradiation. Due to the reduced effect on healthy tissue and better immune preservation, particle therapy may be particularly well suited for combination with DNA repair inhibitors.

Sialic Acids Blockade-Based Chemo-Immunotherapy Featuring Cancer Cell Chemosensitivity and Antitumor Immune Response Synergies.

Immune checkpoint blockade (ICB) has significantly improved the prognosis of patients with cancer, although the majority of such patients achieve low response rates; consequently, new therapeutic approaches are urgently needed. The upregulation of sialic acid-containing glycans is a common characteristic of cancer-related glycosylation, which drives disease progression and immune escape via numerous pathways. Herein, the development of self-assembled core-shell nanoscale coordination polymer nanoparticles loaded with a sialyltransferase inhibitor, referred to as NCP-STI which effectively stripped diverse sialoglycans from cancer cells, providing an antibody-independent pattern to disrupt the emerging Siglec-sialic acid glyco-immune checkpoint is reported. Furthermore, NCP-STI inhibits sialylation of the concentrated nucleoside transporter 1 (CNT1), promotes the intracellular accumulation of anticancer agent gemcitabine (Gem), and enhances Gem-induced immunogenic cell death (ICD). As a result, the combination of NCP-STI and Gem (NCP-STI/Gem) evokes a robust antitumor immune response and exhibits superior efficacy in restraining the growth of multiple murine tumors and pulmonary metastasis. Collectively, the findings demonstrate a novel form of small molecule-based chemo-immunotherapy approach which features sialic acids blockade that enables cooperative effects of cancer cell chemosensitivity and antitumor immune responses for cancer treatment.

Synergistic antitumor immune response mediated by paclitaxel-conjugated nanohybrid oncolytic adenovirus with dendritic cell therapy.

Dendritic cell (DC)-based vaccines have emerged as a promising strategy in cancer immunotherapy due to low toxicity. However, the therapeutic efficacy of DC as a monotherapy is insufficient due to highly immunosuppressive tumor environment. To address these limitations of DC as immunotherapeutic agent, we have developed a polymeric nanocomplex incorporating (1) oncolytic adenovirus (oAd) co-expressing interleukin (IL)-12 and granulocyte-macrophage colony-stimulating factor (GM-CSF) and (2) arginine-grafted bioreducible polymer with PEGylated paclitaxel (APP) to restore antitumor immune surveillance function in tumor milieu and potentiate immunostimulatory attributes of DC vaccine. Nanohybrid complex (oAd/APP) in combination with DC (oAd/APP+DC) induced superior expression level of antitumor cytokines (IL-12, GM-CSF, and interferon gamma) than either oAd/APP or DC monotherapy in tumor tissues, thus resulting in superior intratumoral infiltration of both endogenous and exogenous DCs. Furthermore, oAd/APP+DC treatment led superior migration of DC to secondary lymphoid organs, such as draining lymph nodes and spleen, in comparison with either monotherapy. Superior migration profile of DCs in oAd/APP+DC treatment group resulted in more prolific activation of tumor-specific T cells in these lymphoid organs and greater intratumoral infiltration of T cells. Additionally, oAd/APP+DC treatment led to lower subset of tumor infiltrating lymphocytes and splenocytes being immunosuppressive regulatory T cells than any other treatment groups. Collectively, oAd/APP+DC led to superior induction of antitumor immune response and amelioration of immunosuppressive tumor microenvironment to elicit potent tumor growth inhibition than either monotherapy.

Tumor microenvironment-modulating oncolytic adenovirus combined with GSK-3ß inhibitor enhances antitumor immune response against bladder cancer.

Bladder cancer is a common type of cancer around the world, and the majority of patients are diagnosed with non-muscle-invasive bladder cancer (NMIBC). Although low-risk NMIBC has a good prognosis, the disease recurrence rate and development of treatment-refractory disease remain high in intermediate- to high-risk NMIBC patients. To address these challenges for the treatment of NMIBC, a novel combination therapy composed of an oncolytic adenovirus (oAd) co-expressing interleukin (IL)-12, granulocyte-macrophage colony-stimulating factor (GM-CSF), and relaxin (RLX; HY-oAd) and a clinical-stage glycogen synthase kinase (GSK)-3ß inhibitor (9-ING-41; elraglusib) was investigated in the present report. Our findings demonstrate that HY-oAd and 9-ING-41 combination therapy (HY-oAd+9-ING-41) exerted superior inhibition of tumor growth compared with respective monotherapy in a syngeneic NMIBC tumor model. HY-oAd+9-ING-41 induced high-level tumor extracellular matrix (ECM) degradation and a more potent antitumor immune response than the respective monotherapy. In detail, HY-oAd+9-ING-41 induced superior accumulation of intratumoral T cells, prevention of immune cell exhaustion, and induction of tumor-specific adaptive immune response compared to either monotherapy. Collectively, these results demonstrate that the combination of HY-oAd and 9-ING-41 may be a promising approach to elicit a potent antitumor immune response against bladder cancer.

Dendritic Polymer-Based Nanomedicines Remodel the Tumor Stroma: Improve Drug Penetration and Enhance Antitumor Immune Response.

The dense extracellular matrix (ECM) in solid tumors, contributed by cancer-associated fibroblasts (CAFs), hinders penetration of drugs and diminishes their therapeutic outcomes. A sequential treatment strategy of remodeling the ECM via a CAF modifier (dasatinib, DAS) is proposed to promote penetration of an immunogenic cell death (ICD) inducer (epirubicin, Epi) via apoptotic vesicles, ultimately enhancing the treatment efficacy against breast cancer. Dendritic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA)-based nanomedicines (poly[OEGMA-Dendron(G2)-Gly-Phe-Leu-Gly-DAS] (P-DAS) and poly[OEGMA-Dendron(G2)-hydrazone-Epi] (P-Epi)) are developed for sequential delivery of DAS and Epi, respectively. P-DAS reprograms CAFs to reduce collagen by downregulating collagen anabolism and energy metabolism, thereby reducing the ECM deposition. The regulated ECM can enhance tumor penetration of P-Epi to strengthen its ICD effect, leading to an amplified antitumor immune response. In breast cancer-bearing mice, this approach alleviates the ECM barrier, resulting in reduced tumor burden and increased cytotoxic T lymphocyte infiltration, and more encouragingly, synergizes effectively with anti-programmed cell death 1 (PD-1) therapy, significantly inhibiting tumor growth and preventing lung metastasis. Furthermore, systemic toxicity is barely detectable after sequential treatment with P-DAS and P-Epi. This approach opens a new avenue for treating desmoplastic tumors by metabolically targeting CAFs to overcome the ECM barrier.

Inhibition of MER proto-oncogene tyrosine kinase by an antisense oligonucleotide enhances treatment efficacy of immunoradiotherapy.

BACKGROUND: The combination of radiotherapy and immunotherapy (immunoradiotherapy) has been increasingly used for treating a wide range of cancers. However, some tumors are resistant to immunoradiotherapy. We have previously shown that MER proto-oncogene tyrosine kinase (MerTK) expressed on macrophages mediates resistance to immunoradiotherapy. We therefore sought to develop therapeutics that can mitigate the negative impact of MerTK. We designed and developed a MerTK specific antisense oligonucleotide (ASO) and characterized its effects on eliciting an anti-tumor immune response in mice. METHODS: 344SQR cells were injected into the right legs on day 0 and the left legs on day 4 of 8-12 weeks old female 129sv/ev mice to establish primary and secondary tumors, respectively. Radiation at a dose of 12 Gy was given to the primary tumors on days 8, 9, and 10. Mice received either anti-PD-1, anti-CTLA-4 or/and MerTK ASO starting from day 1 post tumor implantation. The composition of the tumor microenvironment and the level of MerTK on macrophages in the tumor were evaluted by flow cytometry. The expression of immune-related genes was investigated with NanoString. Lastly, the impact of MerTK ASO on the structure of the eye was histologically evaluated. RESULTS: Remarkably, the addition of MerTK ASO to XRT+anti-PD1 and XRT+anti-CTLA4 profoundly slowed the growth of both primary and secondary tumors and significantly extended survival. The ASO significantly reduced the expression of MerTK in tumor-associated macrophages (TAMs), reprograming their phenotype from M2 to M1. In addition, MerTK ASO increased the percentage of Granzyme B+ CD8+ T cells in the secondary tumors when combined with XRT+anti-CTLA4. NanoString results demonstrated that the MerTK ASO favorably modulated immune-related genes for promoting antitumor immune response in secondary tumors. Importantly, histological analysis of eye tissues demonstrated that unlike small molecules, the MerTK ASO did not produce any detectable pathology in the eyes. CONCLUSIONS: The MerTK ASO can significantly downregulate the expression of MerTK on TAMs, thereby promoting antitumor immune response. The combination of MerTK ASO with immunoradiotherapy can safely and significantly slow tumor growth and improve survival.

Targeting metabolic reprogramming promotes the efficacy of transarterial chemoembolization in the rabbit VX2 liver tumor model.

Transarterial chemoembolization (TACE) may prolong the survival of patients with hepatocellular carcinoma (HCC); however, its efficacy is limited due to the high rate of incomplete embolization. Hypoxia after embolization can cause a series of changes in the tumor microenvironment, including lactate dehydrogenase A (LDHA) upregulation. Therefore, the current study assessed the antitumor effect and the underlying mechanism of the LDHA inhibitor, sodium oxamate (Ox), combined with TACE, using the rabbit VX2 liver tumor model. VX2 liver tumor models were created in the left liver lobe of rabbits, and after 14 days of treatments, the rabbits were sacrificed for the collection of the tumor tissues and blood samples. The antitumor effects of Ox, and the combination of Ox and TACE, and changes in the tumor microenvironment after treatments were assessed by histopathological evaluation, and the safety of the treatments was analyzed by measuring changes in the serum levels of alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen and creatinine. The results demonstrated that the combination of Ox and TACE notably improved antitumor effects compared with in the other groups, as it significantly inhibited tumor growth. Additionally, treatment with Ox + TACE downregulated vascular endothelial growth factor and matrix metalloproteinase-9, and enhanced the infiltration of CD3+ and CD8+ T cells into tumor tissues, thus suggesting that Ox + TACE may have a synergistic effect on increasing the infiltration of immune cells in the tumor microenvironment. With a well-tolerated and manageable impairment of hepatorenal function, targeting metabolic reprogramming could promote the efficacy of TACE, thus providing novel avenues for the future clinical management of patients with advanced HCC.

Potent CTLs can be induced against tumor cells in an environment of lower levels of systemic MFG-E8.

The direction and magnitude of immune responses are critically affected when dead cells are disposed of. Milk fat globule-epidermal growth factor-factor 8 (MFG-E8) promotes the engulfment of apoptotic normal and cancerous cells without inducing inflammation. We have previously reported that a certain proportion of the cancer cells express abundant MFG-E8, and that such expression is associated with the shorter survival of patients with esophageal cancer who had received chemotherapy before surgery. However, the influence of tumor-derived and systemically existing MFG-E8 on antitumor immune responses has not yet been fully investigated. Herein, we showed that CTL-dependent antitumor immune responses were observed in mice with no or decreased levels of systemic MFG-E8, and that such responses were enhanced further with the administration of anti-PD-1 antibody. In mice with decreased levels of systemic MFG-E8, the dominance of regulatory T cells in tumor-infiltrating lymphocytes was inverted to CD8+ T cell dominance. MFG-E8 expression by tumor cells appears to affect antitumor immune responses only when the level of systemic MFG-E8 is lower than the physiological status. We have also demonstrated in the clinical setting that lower levels of plasma MFG-E8, but not MFG-E8 expression in tumor cells, before the treatment was associated with objective responses to anti-PD-1 therapy in patients with non-small cell lung cancer. These results suggest that systemic MFG-E8 plays a critical role during the immunological initiation process of antigen-presenting cells to increase tumor-specific CTLs. Regulation of the systemic level of MFG-E8 might induce efficient antitumor immune responses and enhance the potency of anti-PD-1 therapy.

Combination of AAV-delivered tumor suppressor PTEN with anti-PD-1 loaded depot gel for enhanced antitumor immunity.

Recent clinical studies have shown that mutation of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene in cancer cells may be associated with immunosuppressive tumor microenvironment (TME) and poor response to immune checkpoint blockade (ICB) therapy. Therefore, efficiently restoring PTEN gene expression in cancer cells is critical to improving the responding rate to ICB therapy. Here, we screened an adeno-associated virus (AAV) capsid for efficient PTEN gene delivery into B16F10 tumor cells. We demonstrated that intratumorally injected AAV6-PTEN successfully restored the tumor cell PTEN gene expression and effectively inhibited tumor progression by inducing tumor cell immunogenic cell death (ICD) and increasing immune cell infiltration. Moreover, we developed an anti-PD-1 loaded phospholipid-based phase separation gel (PPSG), which formed an in situ depot and sustainably release anti-PD-1 drugs within 42 days in vivo. In order to effectively inhibit the recurrence of melanoma, we further applied a triple therapy based on AAV6-PTEN, PPSG@anti-PD-1 and CpG, and showed that this triple therapy strategy enhanced the synergistic antitumor immune effect and also induced robust immune memory, which completely rejected tumor recurrence. We anticipate that this triple therapy could be used as a new tumor combination therapy with stronger immune activation capacity and tumor inhibition efficacy.

A Recombinant Oncolytic Influenza Virus Carrying GV1001 Triggers an Antitumor Immune Response.

Oncolytic viruses are able to lyse tumor cells selectively in the liver without killing normal hepatocytes, in addition to activating the immune response. Oncolytic virus therapy is expected to revolutionize the treatment of liver cancer, including hepatocellular carcinoma (HCC), one of the most frequent and fatal malignancies. In this study, reverse genetics techniques were exploited to load NA fragments of the A/PuertoRico/8/34 virus (PR8) with GV1001 peptides derived from human telomerase reverse transcriptase. An in vitro assessment of the therapeutic effect of the recombinant oncolytic virus was followed by an in vivo study in mice with HCC. The recombinant virus was verified by sequencing of the recombinant viral gene sequence, and viral virulence was detected by hemagglutination assays and based on the 50% tissue culture infectious dose (TCID50). The morphological structure of the virus was observed by electron microscopy, and GV1001 peptide was localized by cellular immunofluorescence. The selective cytotoxicity of the recombinant oncolytic virus in vitro was demonstrated in cultured HCC cells and normal hepatocytes, as only the tumor cells were killed; the normal cells were not significantly altered. Consistent with the in vitro results, the recombinant oncolytic influenza virus significantly inhibited liver tumor growth in mice in vivo, in addition to inducing an antitumor immune response, including an increase in the number of CD4+ and CD8+ T lymphocytes and, in turn, improving survival. Our results suggest that oncolytic influenza virus carrying GV1001 is a promising immunotherapy in patients with HCC.

Temperature-Sensitive Nanocarbon Hydrogel for Photothermal Therapy of Tumors.

Background: Intelligent hydrogels continue to encounter formidable obstacles in the field of cancer treatment. A wide variety of hydrogel materials have been designed for diverse purposes, but materials with satisfactory therapeutic effects are still urgently needed. Methods: Here, we prepared an injectable hydrogel by means of physical crosslinking. Carbon nanoparticle suspension injection (CNSI), a sentinel lymph node imaging agent that has been widely used in the clinic, with sodium ß-glycerophosphate (ß-GP) were added to a temperature-sensitive chitosan (CS) hydrogel (CS/GP@CN) as an agent for photothermal therapy (PTT). After evaluating the rheological, morphological, and structural properties of the hydrogel, we used 4T1 mouse breast cancer cells and B16 melanoma cells to assess its in vitro properties. Then, we intratumorally injected the hydrogel into BALB/c tumor-bearing mice to assess the in vivo PTT effect, antitumor immune response and the number of lung metastases. Results: Surprisingly, this nanocarbon hydrogel called CS/GP@CN hydrogel not only had good biocompatibility and a great PTT effect under 808nm laser irradiation but also facilitated the maturation of dendritic cells to stimulate the antitumor immune response and had an extraordinary antimetastatic effect in the lungs. Discussion: Overall, this innovative temperature-sensitive nanocarbon hydrogel, which exists in a liquid state at room temperature and transforms to a gel at 37 °C, is an outstanding local delivery platform with tremendous PTT potential and broad clinical application prospects.

Systemic Immunomodulatory Effects of Codonopsis pilosula Glucofructan on S180 Solid-Tumor-Bearing Mice.

The immune functions of the body are intricately intertwined with the onset and advancement of tumors, and immunotherapy mediated by bioactive compounds has exhibited initial effectiveness in overcoming chemotherapy resistance and inhibiting tumor growth. However, the comprehensive interpretation of the roles played by immunologic components in the process of combating tumors remains to be elucidated. In this study, the Codonopsis pilosula glucofructan (CPG) prepared in our previous research was employed as an immunopotentiator, and the impacts of CPG on both the humoral and cellular immunity of S180 tumor-bearing mice were investigated. Results showed that CPG administration of 100 mg/kg could effectively inhibit tumor growth in mice with an inhibitory ratio of 45.37% and significantly improve the expression of Interleukin-2 (IL-2), Interferon-γ (IFN-γ), and Tumor Necrosis Factor-α (TNF-α). Additionally, CPG clearly enhanced B-cell-mediated humoral immunity and immune-cell-mediated cellular immunity, and, finally, induced S180 cell apoptosis by arresting cells in the G0/G1 phase, which might result from the IL-17 signaling pathway. These data may help to improve comprehension surrounding the roles of humoral and cellular immunity in anti-tumor immune responses.

Immunological Assessment of Recent Immunotherapy for Colorectal Cancer.

Colorectal cancer (CRC) is the third most prevalent malignancy with increased incidence and mortality rates worldwide. Traditional treatment approaches have attempted to efficiently target CRC; however, they have failed in most cases, owing to the cytotoxicity and non-specificity of these therapies. Therefore, it is essential to develop an effective alternative therapy to improve the clinical outcomes in heterogeneous CRC cases. Immunotherapy has transformed cancer treatment with remarkable efficacy and overcomes the limitations of traditional treatments. With an understanding of the cancer-immunity cycle and tumor microenvironment evolution, current immunotherapy approaches have elicited enhanced antitumor immune responses. In this comprehensive review, we outline the latest advances in immunotherapy targeting CRC and provide insights into antitumor immune responses reported in landmark clinical studies. We focused on highlighting the combination approaches that synergistically induce immune responses and eliminate immunosuppression. This review aimed to understand the limitations and potential of recent immunotherapy clinical studies conducted in the last five years (2019-2023) and to transform this knowledge into a rational design of clinical trials intended for effective antitumor immune responses in CRC.

SMYD3 represses tumor-intrinsic interferon response in HPV-negative squamous cell carcinoma of the head and neck.

Cancers often display immune escape, but the mechanisms are incompletely understood. Herein, we identify SMYD3 as a mediator of immune escape in human papilloma virus (HPV)-negative head and neck squamous cell carcinoma (HNSCC), an aggressive disease with poor response to immunotherapy with pembrolizumab. SMYD3 depletion induces upregulation of multiple type I interferon (IFN) response and antigen presentation machinery genes in HNSCC cells. Mechanistically, SMYD3 binds to and regulates the transcription of UHRF1, encoding for a reader of H3K9me3, which binds to H3K9me3-enriched promoters of key immune-related genes, recruits DNMT1, and silences their expression. SMYD3 further maintains the repression of immune-related genes through intragenic deposition of H4K20me3. In vivo, Smyd3 depletion induces influx of CD8+ T cells and increases sensitivity to anti-programmed death 1 (PD-1) therapy. SMYD3 overexpression is associated with decreased CD8 T cell infiltration and poor response to neoadjuvant pembrolizumab. These data support combining SMYD3 depletion strategies with checkpoint blockade to overcome anti-PD-1 resistance in HPV-negative HNSCC.

Nuanced role for dendritic cell intrinsic IRE1 RNase in the regulation of antitumor adaptive immunity.

In cancer, activation of the IRE1/XBP1s axis of the unfolded protein response (UPR) promotes immunosuppression and tumor growth, by acting in cancer cells and tumor infiltrating immune cells. However, the role of IRE1/XBP1s in dendritic cells (DCs) in tumors, particularly in conventional type 1 DCs (cDC1s) which are cellular targets in immunotherapy, has not been fully elucidated. Here, we studied the role of IRE1/XBP1s in subcutaneous B16/B78 melanoma and MC38 tumors by generating loss-of-function models of IRE1 and/or XBP1s in DCs or in cDC1s. Data show that concomitant deletion of the RNase domain of IRE1 and XBP1s in DCs and cDC1s does not influence the kinetics of B16/B78 and MC38 tumor growth or the effector profile of tumor infiltrating T cells. A modest effect is observed in mice bearing single deletion of XBP1s in DCs, which showed slight acceleration of melanoma tumor growth and dysfunctional T cell responses, however, this effect was not recapitulated in animals lacking XBP1 only in cDC1s. Thus, evidence presented here argues against a general pro-tumorigenic role of the IRE1/XBP1s pathway in tumor associated DC subsets.