IFN-γ and CD38 in Hyperprogressive Cancer Development

ZDHHC9-mediated CD38 palmitoylation stabilizes CD38 expression and promotes pancreatic cancer growth

The cluster of differentiation 38 (CD38) is a multifunctional transmembrane protein involved in numerous physiological and pathological processes including aging, neurodegenerative diseases, and tumorigenesis, hence is an attractive drug target. However, the mechanisms underlying the regulation of CD38 expression remain enigmatic. Herein, we report for the first time that CD38 is palmitoylated at Cys16, and that S-palmitoylation is required to maintain CD38 protein expression in tumor cells. Furthermore, we identify DHHC9 as the palmitoyl transferase and APT1 as the acylprotein thioesterase responsible for this crucial post-translational modification. Finally, we designed a competitive peptide of CD38 palmitoylation that decreases CD38 expression in tumor cells and suppresses tumor progression in vivo. These findings provide novel insight into CD38 regulation and highlight potential therapeutic strategies targeting CD38 palmitoylation for cancer treatment.

Multiple mechanisms and applications of tertiary lymphoid structures and immune checkpoint blockade

BACKGROUND

Immune checkpoint blockade (ICB) inhibits tumor immune escape and has significantly advanced tumor therapy. However, ICB benefits only a minority of patients treated and may lead to many immune-related adverse events. Therefore, identifying factors that can predict treatment outcomes, enhance synergy with ICB, and mitigate immune-related adverse events is urgently needed.

MAIN TEXT

Tertiary lymphoid structures (TLS) are ectopic lymphoid tissues that arise from the tumor periphery. They have been found to be associated with better prognosis and improved clinical outcomes after ICB therapy. TLS may help address the problems associated with ICB. The multiple mechanisms of action between TLS and ICB remain unknown. This paper described potential mechanisms of interaction between the two and explored their potential applications.

PD-L1 and IFN-γ modulate Non-Small Cell Lung Cancer (NSCLC) cell plasticity associated to immune checkpoint inhibitor (ICI)-mediated hyperprogressive disease (HPD)

BACKGROUND

Non-Small Cell Lung Cancer (NSCLC) is the leading cause of cancer death worldwide. Although immune checkpoint inhibitors (ICIs) have shown remarkable clinical efficacy, they can also induce a paradoxical cancer acceleration, known as hyperprogressive disease (HPD), whose causative mechanisms are still unclear.

METHODS

This study investigated the mechanisms of ICI resistance in an HPD-NSCLC model. Two primary cell cultures were established from samples of a NSCLC patient, before ICI initiation ("baseline", NSCLC-B) and during HPD ("hyperprogression", NSCLC-H). The cell lines were phenotypically and molecularly characterized through immunofluorescence, Western Blotting and RNA-Seq analysis. To assess cell plasticity and aggressiveness, cellular growth patterns were evaluated both in vitro and in vivo through 2D and 3D cell growth assays and patient-derived xenografts establishment. In vitro investigations, including the evaluation of cell sensitivity to interferon-gamma (IFN-γ) and cell response to PD-L1 modulation, were conducted to explore the influence of these factors on cell plasticity regulation.

RESULTS

NSCLC-H exhibited increased expression of specific CD44 isoforms and a more aggressive phenotype, including organoid formation ability, compared to NSCLC-B. Plastic changes in NSCLC-H were well described by a deep transcriptome shift, that also affected IFN-γ-related genes, including PD-L1. IFN-γ-mediated cell growth inhibition was compromised in both 2D-cultured NSCLC-B and NSCLC-H cells. Further, the cytokine induced a partial activation of both type I and type II IFN-pathway mediators, together with a striking increase in NSCLC-B growth in 3D cell culture systems. Finally, low IFN-γ doses and PD-L1 modulation both promoted plastic changes in NSCLC-B, increasing CD44 expression and its ability to produce spheres.

CONCLUSIONS

Our findings identified plasticity as a relevant hallmark of ICI-mediated HPD by demonstrating that ICIs can modulate the IFN-γ and PD-L1 pathways, driving tumor cell plasticity and fueling HPD development.

Exploring the Frequency and Risk Factors of Hyperprogressive Disease in Patients with Advanced Melanoma Treated with Immune Checkpoint Inhibitors

Hyperprogressive disease (HPD) is described as the unexpected rapid growth of a tumour accompanied by a decline in performance status. While immune checkpoint inhibitors (ICIs) have improved outcomes in advanced melanoma, HPD remains a significant challenge in a subset of patients. Although HPD has been extensively studied in various solid tumours, research specifically focusing on advanced melanoma remains limited. We analysed 158 advanced melanoma patients, with 66.5% (n = 105) receiving anti-PD-1 and 33.5% (n = 53) receiving nivolumab plus ipilimumab. The median overall survival was 4.9 months for patients with HPD compared to 8.9 months for those with progressive disease without HPD (p = 0.014). Factors associated with HPD included liver metastasis (p = 0.002), three or more metastatic sites (p < 0.001), elevated lactate dehydrogenase levels (p = 0.004), and Eastern cooperative oncology group performance status ≥2 (p = 0.023). Multivariate analysis identified the Royal Marsden Hospital score (HR 3.675, 95% CI: 1.166-11.580, p = 0.026) as an independent risk factor for HPD, with the MDA-ICI score also trending towards significance (HR 4.466, 95% CI: 0.947-21.061, p = 0.059). This study provides valuable insights into the frequency and factors associated with HPD in advanced melanoma patients treated with ICIs, highlighting the relevance of clinical markers and scoring systems in predicting HPD risk.

A CD38-directed, single-chain T-cell engager targets leukemia stem cells through IFN-γ-induced CD38 expression

ABSTRACT

Treatment resistance of leukemia stem cells (LSCs) and suppression of the autologous immune system represent major challenges to achieve a cure in acute myeloid leukemia (AML). Although AML blasts generally retain high levels of surface CD38 (CD38pos), LSCs are frequently enriched in the CD34posCD38neg blast fraction. Here, we report that interferon gamma (IFN-γ) reduces LSCs clonogenic activity and induces CD38 upregulation in both CD38pos and CD38neg LSC-enriched blasts. IFN-γ-induced CD38 upregulation depends on interferon regulatory factor 1 transcriptional activation of the CD38 promoter. To leverage this observation, we created a novel compact, single-chain CD38-CD3 T-cell engager (BN-CD38) designed to promote an effective immunological synapse between CD38pos AML cells and both CD8pos and CD4pos T cells. We demonstrate that BN-CD38 engages autologous CD4pos and CD8pos T cells and CD38pos AML blasts, leading to T-cell activation and expansion and to the elimination of leukemia cells in an autologous setting. Importantly, BN-CD38 engagement induces the release of high levels of IFN-γ, driving the expression of CD38 on CD34posCD38neg LSC-enriched blasts and their subsequent elimination. Critically, although BN-CD38 showed significant in vivo efficacy across multiple disseminated AML cell lines and patient-derived xenograft models, it did not affect normal hematopoietic stem cell clonogenicity and the development of multilineage human immune cells in CD34pos humanized mice. Taken together, this study provides important insights to target and eliminate AML LSCs.

Hyperprogression of buccal squamous cell carcinoma accompanied by carotid sinus syndrome: A case report

Buccal squamous cell carcinoma (BSCC) is a highly malignant oral cancer with high recurrence rates, poor prognosis, and significant mortality. Most patients are diagnosed at a locally advanced or metastatic stage, requiring a combination of treatments such as surgery, radiotherapy, chemotherapy, and immunotherapy. Hyperprogression refers to rapid tumor growth increased tumor burden, and worsening patient condition, representing a severe adverse effect of immunotherapy in BSCC is extremely rare, with limited salvage treatment options and poor prognosis. In October 2021, a locally advanced BSCC patient was treated at the Second Xiangya Hospital of Central South University. After undergoing radical surgery, the patient experienced rapid recurrence with cervical lymph node and bilateral lung metastases. Following two cycles of chemotherapy combined with immunotherapy, the primary buccal lesion, cervical lymph nodes, and pulmonary metastases significantly increased, indicative of hyperprogression. Concurrently, the patient developed carotid sinus syndrome, characterized by frequent bradycardia, hypotension, and altered consciousness, leading to an overall survival of 4 months. Understanding the causes and high-risk factors of hyperprogression and developing strategies for its prevention remain critical challenges in the era of cancer immunotherapy.

Muramyl dipeptide CD10 monoclonal antibody immunoconjugates inhibited acute leukemia in nude mice

Minimal residual disease (MRD) is one of the causes of leukemia recurrence. Previously, we developed anti-CD10 mAb conjugated to muramyl dipeptide immunoconjugate (MDP-Ab) for immune enhancement. The present study aimed to investigate anti-leukemia effect of MDP-Ab administered via different methods in leukemia ectopic graft nude mouse model. BALB/c nude mice were injected with Nalm-6 cells subcutaneously to establish leukemia xenografts in nude mice as a model. MDP-Ab or/and human lymphocytes (LYM) was injected into different sites of the nude mice. Immunohistochemistry staining of CDs in the bone marrow, liver and spleen was performed. IFN-γ was detected by ELISA. We detected the metastasis of leukemia cells to the liver, spleen and bone marrow in nude mouse leukemia model. MDP-Ab and LYM inhibited the growth of tumors, and simultaneous injection of MDP-Ab and LYM into the tumor inhibited the growth of tumors. IFN-γ levels in MDP-Ab (ca) + h-LYM (ca) group, MDP-Ab (ca) + h-LYM (ip) group, MDP-Ab (iv) + h-LYM (ip) group and PBS (ca) + h-LYM (ca) group were significantly higher than those in control group, while IFN-γ level in MDP-Ab (ca) + h-LYM (ca) group was the highest. Moreover, MDP-Ab and h-LYM promoted the expression of hCD4 and hCD8, with the highest expression in MDP-Ab (ca) + h-LYM (ca) group. In conclusion, MDP-Ab effectively promoted the production of IFN-γ, enhanced the antitumor immunity of T lymphocytes and inhibited leukemia.

Evolving roles of CD38 metabolism in solid tumour microenvironment

Given that plenty of clinical findings and reviews have already explained in detail on the progression of CD38 in multiple myeloma and haematological system tumours, here we no longer give unnecessary discussion on the above progression. Though therapeutic antibodies have been regarded as a greatest breakthrough in multiple myeloma immunotherapies due to the durable anti-tumour responses in the clinic, but the role of CD38 in the immunologic regulation and evasion of non-hematopoietic solid tumours are just initiated and controversial. Therefore, we will focus on the bio-function of CD38 enzymatic substrates or metabolites in the variety of non-hematopoietic malignancies and the potential therapeutic value of targeting the CD38-NAD+ or CD38-cADPR/ADPR signal axis. Though limited, we review some ongoing researches and clinical trials on therapeutic approaches in solid tumour as well.

Multiplex immunofluorescence and single-cell transcriptomic profiling reveal the spatial cell interaction networks in the non-small cell lung cancer microenvironment

BACKGROUND

Conventional immunohistochemistry technologies were limited by the inability to simultaneously detect multiple markers and the lack of identifying spatial relationships among cells, hindering understanding of the biological processes in cancer immunology.

METHODS

Tissue slices of primary tumours from 553 IA∼IIIB non-small cell lung cancer (NSCLC) cases were stained by multiplex immunofluorescence (mIF) assay for 10 markers, including CD4, CD38, CD20, FOXP3, CD66b, CD8, CD68, PD-L1, CD133 and CD163, evaluating the amounts of 26 phenotypes of cells in tumour nest and tumour stroma. StarDist depth learning model was utilised to determine the spatial location of cells based on mIF graphs. Single-cell RNA sequencing (scRNA-seq) on four primary NSCLC cases was conducted to investigate the putative cell interaction networks.

RESULTS

Spatial proximity among CD20+ B cells, CD4+ T cells and CD38+ T cells (r2  = 0.41) was observed, whereas the distribution of regulatory T cells was associated with decreased infiltration levels of CD20+ B cells and CD38+ T cells (r2  = -0.45). Univariate Cox analyses identified closer proximity between CD8+ T cells predicted longer disease-free survival (DFS). In contrast, closer proximity between CD133+ cancer stem cells (CSCs), longer distances between CD4+ T cells and CD20+ B cells, CD4+ T cells and neutrophils, and CD20+ B cells and neutrophils were correlated with dismal DFS. Data from scRNA-seq further showed that spatially adjacent N1-like neutrophils could boost the proliferation and activation of T and B lymphocytes, whereas spatially neighbouring M2-like macrophages showed negative effects. An immune-related risk score (IRRS) system aggregating robust quantitative and spatial prognosticators showed that high-IRRS patients had significantly worse DFS than low-IRRS ones (HR 2.72, 95% CI 1.87-3.94, p < .001).

CONCLUSIONS

We developed a framework to analyse the cell interaction networks in tumour microenvironment, revealing the spatial architecture and intricate interplays between immune and tumour cells.

Hyperprogressive disease in non-small cell lung cancer treated with immune checkpoint inhibitor therapy, fact or myth?

The therapeutic landscape for patients with non-small cell lung cancer (NSCLC) has dramatically evolved with the development and adoption of immune checkpoint inhibitors (ICI) as front-line therapy. These novel antibodies target the interactions in immunoregulatory pathways, between programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1), or cytotoxic T-lymphocyte antigen 4 (CTLA-4) and B7, resulting in the activation of T cells and cytotoxic response to induce an immunologic response. ICIs have demonstrated significant survival benefits and sustained responses in the treatment of NSCLC leading to the long-term survival of up to 5 year. One unusual response to ICI is a phenomenon termed Hyperprogressive Disease (HYD), which occurs in a subset of patients for whom ICI therapy can induce rapid disease growth, which ultimately leads to poorer outcomes with an incidence rate ranging from 5 to 37% in NSCLC patients. Prior reviews demonstrated that HYD can be defined by rapid tumor progression, deterioration of patient’s symptoms or new onset of disease. The mechanism of HYD could be related to genomic and tumor microenvironment changes and altered immune response. It will be important to establish a common definition of HYD for future research and clinical care.

Tumor-intrinsic NLRP3-HSP70-TLR4 axis drives premetastatic niche development and hyperprogression during anti-PD-1 immunotherapy

The tumor-intrinsic NOD-, LRR- and pyrin domain-containing protein-3 (NLRP3) inflammasome-heat shock protein 70 (HSP70) signaling axis is triggered by CD8⁺ T cell cytotoxicity and contributes to the development of adaptive resistance to anti-programmed cell death protein 1 (PD-1) immunotherapy by recruiting granulocytic polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) into the tumor microenvironment. Here, we demonstrate that the tumor NLRP3-HSP70 axis also drives the accumulation of PMN-MDSCs into distant lung tissues in a manner that depends on lung epithelial cell Toll-like receptor 4 (TLR4) signaling, establishing a premetastatic niche that supports disease hyperprogression in response to anti-PD-1 immunotherapy. Lung epithelial HSP70-TLR4 signaling induces the downstream Wnt5a-dependent release of granulocyte colony-stimulating factor (G-CSF) and C-X-C motif chemokine ligand 5 (CXCL5), thus promoting myeloid granulopoiesis and recruitment of PMN-MDSCs into pulmonary tissues. Treatment with anti-PD-1 immunotherapy enhanced the activation of this pathway through immunologic pressure and drove disease progression in the setting of Nlrp3 amplification. Genetic and pharmacologic inhibition of NLRP3 and HSP70 blocked PMN-MDSC accumulation in the lung in response to anti-PD-1 therapy and suppressed metastatic progression in preclinical models of melanoma and breast cancer. Elevated baseline concentrations of plasma HSP70 and evidence of NLRP3 signaling activity in tumor tissue specimens correlated with the development of disease hyperprogression and inferior survival in patients with stage IV melanoma undergoing anti-PD-1 immunotherapy. Together, this work describes a pathogenic mechanism underlying the phenomenon of disease hyperprogression in melanoma and offers candidate targets and markers capable of improving the management of patients with melanoma.

NMI: a potential biomarker for tumor prognosis and immunotherapy

N-Myc and STAT Interactor protein (NMI) is an interferon inducible protein participating in various cellular activities, and is widely involved in the process of tumorigenesis and progression. Studies have shown that the loss of NMI expression in breast cancer can promote its progression by inducing epithelial-mesenchymal transition (EMT). However, the expression level of NMI in other tumors and its impact on immune cell infiltration, patient prognosis, and drug treatment are still unclear. Here, we analyzed the role of NMI in pan-cancer through multiple omics data. We found that NMI was abnormally expressed in a variety of tumor tissues. The expression of NMI was closely related to the unique molecular and immunotyping, diagnosis and prognosis of various tumor tissues. In addition, we identified the main proteins that interact with NMI, and focused on the relationship between the clinical parameters of lower grade glioma (LGG) and NMI expression. Subsequently, we found that the expression of NMI was correlated with the infiltration of multiple immune cells and the expression of immune checkpoints. Finally, we also found that the expression of NMI was correlated with the sensitivity to multiple antitumor drugs. In conclusion, our comprehensive pan-cancer analysis of NMI revealed that it is a potential molecular marker for tumor diagnosis and treatment, plays an important role in tumor immunity, and is a promising molecular target for cancer treatment.

Myeloid-derived Suppressor Cells Activate Liver Natural Killer Cells in a Murine Model in Uveal Melanoma

OBJECTIVE

Elevated myeloid-derived suppressor cells (MDSCs) in many malignancies are associated with the increased risk for metastases and poor prognosis. Therefore, a mouse model of intraocular melanoma was established to explore how MDSCs influence liver metastases.

METHODS

In this study, murine B16LS melanoma cells were transplanted into the posterior compartment (PC) of the eye of C57BL/6 mice. Leucocytes from the liver of naive mice and mice bearing melanoma liver metastasis were isolated using isotonic Percoll centrifugation, examined by flow cytometry for their expression of Gr1, CD11b, F4/80, RAE-1, and Mult-1, and further isolated for MDSCs and natural killer (NK) cells. The effects of MDSCs on NK cells were tested by coculturing and assessing the ability of NK cells to produce interferon-gamma (IFN-γ) by ELISA and NK cell cytotoxicity by ³H-thymidine incorporation assay. The impact of IFN-γ on liver metastases was examined via selectively depleting IFN-γ in vivo.

RESULTS

The results showed that mice with liver metastases had increased levels of CD11b⁺Gr1⁺F4/80⁺ as well as CD11b⁺Gr1⁺F4/80^- MDSCs. MDSCs significantly enhanced the generation of IFN-γ together with the cytotoxicity of the NK cells. Furthermore, these effects were cell-cell contact-dependent. Although IFN-γ was not of a toxic nature to the melanoma cells, it profoundly inhibited B16LS cell proliferation. Depleting IFN-γ in vivo led to increased liver metastases.

CONCLUSION

All these findings first revealed that MDSCs accumulated in liver metastasis of intraocular melanoma could activate the NK cells to produce an effective anti-tumor immune response. Thus, the MDSCs' performance in different tumor models would need more investigation to boost current immunotherapy modalities.

Engineered DBCO+PD-1 Nanovesicles Carrying 1-MT for Cancer-Targeted Immunotherapy

Liver cancer cells evade immune surveillance and anticancer response through various pathways, including the programmed death-ligand 1 (PD-L1)/programmed death-1 (PD-1) immune checkpoint axis that exhausts CD8⁺ T cells. Inhibitors or antibodies of the PD-L1/PD-1 signaling axis are considered promising drugs for cancer immunotherapy and exhibit favorable clinical responses. However, adverse effects, immune tolerance, and delivery barriers of most patients limit the clinical application of PD-L1/PD-1 antibodies. Thus, it is critical to develop a novel delivery strategy to enhance anticancer immunotherapy. In this study, we bioengineered cell membrane-derived nanovesicles (NVs) presenting PD-1 proteins and dibenzocyclooctyne (DBCO) to encapsulate 1-methyltryptophan (1-MT) (DBCO+PD-1@1-MT NVs). DBCO can specifically interact with N-azidoacetylmannosamine-tetraacetylate (Ac₄ManN₃) labeled onto metabolic cells for targeted killing of cancers. We next explored the effects of DBCO+PD-1@1-MT NVs on anticancer Hepa1-6 cells in vitro and in vivo. Results showed that PD-1@1-MT NVs dramatically inhibited Hepa1-6 proliferation, promoted peripheral blood mononuclear cell (PBMC) expansion, and strengthened anticancer therapy via blockading the PD-1/PD-L1 immune checkpoint axis, owing to the 1-methyltryptophan (1-MT) enhancement of anticancer immunotherapy efficacy through suppressing the activity of indoleamine 2,3-dioxygenase (IDO). Thus, 1-MT was encapsulated into PD-1 NVs to synergistically enhance cancer immunotherapy. Results have shown that PD-1@1-MT NVs obviously attenuated tumor growth, promoting IFN-γ production, increasing the T cells infiltration in tumors and spleens, and improving the survival period of tumor-bearing mice compared to monotherapy. Therefore, we propose a promising delivery strategy of the combination of DBCO+PD-1 NVs and 1-MT for specific and effective cancer-targeted immunotherapy.

Hypoxia-Regulated Tumor-Derived Exosomes and Tumor Progression: A Focus on Immune Evasion

Tumor cells express a high quantity of exosomes packaged with unique cargos under hypoxia, an important characteristic feature in solid tumors. These hypoxic tumor-derived exosomes are, crucially, involved in the interaction of cancer cells with their microenvironment, facilitating not only immune evasion, but increased cell growth and survival, enhanced angiogenesis, epithelial–mesenchymal transition (EMT), therapeutic resistance, autophagy, pre-metastasis, and metastasis. This paper explores the tumor microenvironment (TME) remodeling effects of hypoxic tumor-derived exosome towards facilitating the tumor progression process, particularly, the modulatory role of these factors on tumor cell immune evasion through suppression of immune cells, expression of surface recognition molecules, and secretion of antitumor soluble factor. Tumor-expressed exosomes educate immune effector cells, including macrophages, monocytes, T cells, natural killer (NK) cells, dendritic cells (DCs), γδ T lymphocytes, regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), mast cells, and B cells, within the hypoxic TME through the release of factors that regulate their recruitment, phenotype, and function. Thus, both hypoxia and tumor-derived exosomes modulate immune cells, growth factors, cytokines, receptor molecules, and other soluble factors, which, together, collaborate to form the immune-suppressive milieu of the tumor environment. Exploring the contribution of exosomal cargos, such as RNAs and proteins, as indispensable players in the cross-talk within the hypoxic tumor microenvironmental provides a potential target for antitumor immunity or subverting immune evasion and enhancing tumor therapies.

Hyperprogression under treatment with immune-checkpoint inhibitors in patients with gastrointestinal cancer: A natural process of advanced tumor progression?

Immunotherapy has shown great promise in treating various types of malignant tumors. However, some patients with gastrointestinal cancer have been known to experience rapid disease progression after treatment, a situation referred to as hyperprogressive disease (HPD). This minireview focuses on the definitions and potential mechanisms of HPD, natural disease progression in gastrointestinal malignancies, and tumor immunological microenvironment.

Hyperprogression, a challenge of PD-1/PD-L1 inhibitors treatments: potential mechanisms and coping strategies

Immunotherapy is now a mainstay in cancer treatments. Programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) immune checkpoint inhibitor (ICI) therapies have opened up a new venue of advanced cancer immunotherapy. However, hyperprogressive disease (HPD) induced by PD-1/PD-L1 inhibitors caused a significant decrease in the overall survival (OS) of the patients, which compromise the efficacy of PD-1/PD-L1 inhibitors. Therefore, HPD has become an urgent issue to be addressed in the clinical uses of PD-1/PD-L1 inhibitors. The mechanisms of HPD remain unclear, and possible predictive factors of HPD are not well understood. In this review, we summarized the potential mechanisms of HPD and coping strategies that can effectively reduce the occurrence and development of HPD.

Profiling Tumor Immune Microenvironment of Non-Small Cell Lung Cancer Using Multiplex Immunofluorescence

This study attempted to profile the tumor immune microenvironment (TIME) of non-small cell lung cancer (NSCLC) by multiplex immunofluorescence of 681 NSCLC cases. The number, density, and proportion of 26 types of immune cells in tumor nest and tumor stroma were evaluated, revealing some close interactions particularly between intrastromal neutrophils and intratumoral regulatory T cells (Treg) (r² = 0.439, P < 0.001), intrastromal CD4+CD38+ T cells and CD20-positive B cells (r² = 0.539, P < 0.001), and intratumoral CD8-positive T cells and M2 macrophages expressing PD-L1 (r² = 0.339, P < 0.001). Three immune subtypes correlated with distinct immune characteristics were identified using the unsupervised consensus clustering approach. The immune-activated subtype had the longest disease-free survival (DFS) and demonstrated the highest infiltration of CD4-positive T cells, CD8-positive T cells, and CD20-positive B cells. The immune-defected subtype was rich in cancer stem cells and macrophages, and these patients had the worst prognosis. The immune-exempted subtype had the highest levels of neutrophils and Tregs. Intratumoral CD68-positive macrophages, M1 macrophages, and intrastromal CD4+ cells, CD4+FOXP3- cells, CD8+ cells, and PD-L1+ cells were further found to be the most robust prognostic biomarkers for DFS, which were used to construct and validate the immune-related risk score for risk stratification (high vs. median vs. low) and the prediction of 5-year DFS rates (23.2% vs. 37.9% vs. 43.1%, P < 0.001). In conclusion, the intricate and intrinsic structure of TIME in NSCLC was demonstrated, showing potency in subtyping and prognostication.

Hyperprogression of a mismatch repair-deficient colon cancer in a humanized mouse model following administration of immune checkpoint inhibitor pembrolizumab

Immunotherapy is an established treatment modality in oncology. However, in addition to primary or acquired therapy resistance with immune checkpoint blockade (ICB), hyperprogressive disease (HPD) or hyperprogression (HP) with acceleration of tumor growth occurs in a subset of patients receiving ICB therapy. A validated and predictive animal model would help investigate HPD/HP to develop new approaches for this challenging clinical entity. Using human cytotoxic T-cell line TALL-104 injected intraperitoneally into immunodeficient NCRU-nude athymic mice bearing mismatch repair-deficient (MMR-d) human colon carcinoma HCT116 p53-null (but not wild-type p53) tumor xenograft, we observed accelerated tumor growth after PD-1 blockade with pembrolizumab administration. There was increased colon tumor cell proliferation as determined by immunohistochemical Ki67 staining of tumor sections. There was no increase in MDM2 or MDM4/MDMX in the p53-null HCT116 cells versus the wild-type p53-expressing isogenic tumor cells, suggesting the effects in this model may be MDM2 or MDM4/MDMX-independent. Human cytokine profiling revealed changes in IFN-γ, TRAIL-R2/TNFRSF10B, TRANCE/TNFSF11/RANK L, CCL2/JE/MCP-1, Chitinase 3-like 1, IL-4 and TNF-α. This represents a novel humanized HPD mouse model with a link to deficiency of the p53 pathway of tumor suppression in the setting of MMR-d. Our novel humanized preclinical TALL-104/p53-null HCT116 mouse model implicates p53-deficiency in an MMR-d tumor as a possible contributor to HPD/HP and may help with evaluating therapeutic strategies in cancer immunotherapy to extend clinical benefits of ICB's in a broader patient population.

The Next-Generation of Combination Cancer Immunotherapy: Epigenetic Immunomodulators Transmogrify Immune Training to Enhance Immunotherapy

Cancer immunotherapy harnesses the immune system by targeting tumor cells that express antigens recognized by immune system cells, thus leading to tumor rejection. These tumor-associated antigens include tumor-specific shared antigens, differentiation antigens, protein products of mutated genes and rearrangements unique to tumor cells, overexpressed tissue-specific antigens, and exogenous viral proteins. However, the development of effective therapeutic approaches has proven difficult, mainly because these tumor antigens are shielded, and cells primarily express self-derived antigens. Despite innovative and notable advances in immunotherapy, challenges associated with variable patient response rates and efficacy on select tumors minimize the overall effectiveness of immunotherapy. Variations observed in response rates to immunotherapy are due to multiple factors, including adaptative resistance, competency, and a diversity of individual immune systems, including cancer stem cells in the tumor microenvironment, composition of the gut microbiota, and broad limitations of current immunotherapeutic approaches. New approaches are positioned to improve the immune response and increase the efficacy of immunotherapies, highlighting the challenges that the current global COVID-19 pandemic places on the present state of immunotherapy.