Interferons and the Immunogenic Effects of Cancer Therapy

CBX3 antagonizes IFNγ/STAT1/PD-L1 axis to modulate colon inflammation and CRC chemosensitivity

As an important immune stimulator and modulator, IFNγ is crucial for gut homeostasis and its dysregulation links to diverse colon pathologies, such as colitis and colorectal cancer (CRC). Here, we demonstrated that the epigenetic regulator, CBX3 (also known as HP1γ) antagonizes IFNγ signaling in the colon epithelium by transcriptionally repressing two critical IFNγ-responsive genes: STAT1 and CD274 (encoding Programmed death-ligand 1, PD-L1). Accordingly, CBX3 deletion resulted in chronic mouse colon inflammation, accompanied by upregulated STAT1 and CD274 expressions. Chromatin immunoprecipitation indicated that CBX3 tethers to STAT1 and CD274 promoters to inhibit their expression. Reversely, IFNγ significantly reduces CBX3 binding to these promoters and primes gene expression. This antagonist effect between CBX3 and IFNγ on STAT1/PD-L1 expression was also observed in CRC. Strikingly, CBX3 deletion heightened CRC cells sensitivity to IFNγ, which ultimately enhanced their chemosensitivity under IFNγ stimulation in vitro with CRC cells and in vivo with a syngeneic mouse tumor model. Overall, this work reveals that by negatively tuning IFNγ-stimulated immune genes' transcription, CBX3 participates in modulating colon inflammatory response and CRC chemo-resistance.

Inhibition of SIRT7 promotes STAT1 activation and STAT1-dependent signaling in hepatocellular carcinoma

The signal transducer and activator of transcription 1 (STAT1) plays a crucial role in regulating tumor progression. However, the mechanisms governing its phosphorylation and biological functions remain incompletely understood. Here, we present compelling evidence indicating that knockdown of SIRT7 inhibits Smurf1-induced ubiquitination of STAT1, consequently impeding the proteasome pathway degradation of STAT1. This inhibition leads to increased stability of STAT1 and enhanced binding to JAK1. Importantly, SIRT7 exerts a negative regulatory effect on STAT1 activation and IFN-γ/STAT1 signaling in hepatocellular carcinoma (HCC). Etoposide treatment not only facilitates STAT1 activation but also downregulates SIRT7 expression. Notably, knockdown of STAT1 in SIRT7-deficient cells attenuates the increase in cell apoptosis induced by Etoposide treatment. In conclusion, our data shed light on the intricate interplay between ubiquitination, STAT1, SIRT7, and Smurf1, elucidating their impact on STAT1-related signaling. These insights contribute to a more comprehensive understanding of the molecular mechanisms involved in STAT1 regulation and suggest potential avenues for the development of targeted therapies against cancer.

TNF-α-induced down-regulation of type I interferon receptor contributes to acquired resistance of cervical squamous cancer to Cisplatin

We aimed to investigate the effects of tumor necrosis factor (TNF)-α on the expression of interferon α/β receptor subunit 1 (IFNAR1) and cervical squamous cancer (CSCC) resistance to Cisplatin, as well as the underlying mechanisms. Kaplan-Meier analysis was used to plot the overall survival curves. SiHa cells were treated with 20 ng/ml TNF-α to determine cell proliferation in human CSCC cells and the expression of IFNAR1. The effects of TNF-α on the downstream signaling pathway, including casein kinase 1α (CK1α), were investigated using the caspase protease inhibitor FK009, the c-Jun kinase inhibitor SP600125, and the nuclear factor kappa-B inhibitor ammonium pyrrolidinedithiocarbamate (PDTC). TNF-α induced down-regulation of IFNAR1 in human CSCC cells and promoted proliferation of SiHa cells. SiHa cells were transfected with the catalytic inactive mutant CK1α K49A, and the ability of TNF-α to induce down-regulation of IFNAR1 expression was found to be significantly diminished in this context. FK009 and PDTC had no obvious effect on the expression of CK1α, however, SP600125 significantly reduced the expression of CK1α in the presence of TNF-α. SiHa cells treated with TNF-α showed reduced sensitivity to Cisplatin and exhibited higher cell viability, while the sensitivity of SiHa cells to Cisplatin was restored after treatment with CK1α inhibitor D4476. Additionally, we constructed a TNF-α overexpressing SiHa cell line and a transplanted tumor model. The results were similar to those of in vitro efficacy. We demonstrate that TNF-α-induced down-regulation of type I interferon receptor contributes to acquired resistance of cervical squamous cancer to Cisplatin.

Identification and validation of a seven cuproptosis-associated lncRNA signature to predict the prognosis of endometrial cancer

OBJECTIVE

Endometrial cancer (EC) is one of the most prevalent cancers in women. Long non-coding RNAs (lncRNAs) are potential diagnostic biomarkers in patients with EC.

METHODS

We obtained clinical information and transcriptome data for 552 patients with EC from The Cancer Genome Atlas database. Cuproptosis-associated lncRNAs were obtained through Pearson's correlation analysis. Univariate and multivariate Cox regression analyses were applied and a signature predicting overall survival (OS) among patients with EC was constructed. We also analyzed the tumor immune microenvironment and drug sensitivity. The results were validated by quantitative real time-polymerase chain reaction, and 5-ethynyl-2'-deoxyuridine and wound-healing assays.

RESULTS

Seven cuproptosis-associated lncRNAs related to prognosis were screened out and a signature was constructed. OS was significantly superior in the low-risk group. In addition, patients in the low-risk group had more CD8+ T cell infiltration, a stronger type II interferon response, and greater cisplatin sensitivity. Expression levels of some of the lncRNAs were significantly increased by cuproptosis. Furthermore, silencing of lncRNA AC084117.1 significantly inhibited the proliferation and migration of EC cells.

CONCLUSION

We constructed a seven cuproptosis-associated lncRNA signature to predict the prognosis of patients with EC with good predictive power.

Localization, tissue biology and T cell state - implications for cancer immunotherapy

Tissue localization is a critical determinant of T cell immunity. CD8+ T cells are contact-dependent killers, which requires them to physically be within the tissue of interest to kill peptide-MHC class I-bearing target cells. Following their migration and extravasation into tissues, T cells receive many extrinsic cues from the local microenvironment, and these signals shape T cell differentiation, fate and function. Because major organ systems are variable in their functions and compositions, they apply disparate pressures on T cells to adapt to the local microenvironment. Additional complexity arises in the context of malignant lesions (either primary or metastatic), and this has made understanding the factors that dictate T cell function and longevity in tumours challenging. Moreover, T cell differentiation state influences how cues from the microenvironment are interpreted by tissue-infiltrating T cells, highlighting the importance of T cell state in the context of tissue biology. Here, we review the intertwined nature of T cell differentiation state, location, survival and function, and explain how dysfunctional T cell populations can adopt features of tissue-resident memory T cells to persist in tumours. Finally, we discuss how these factors have shaped responses to cancer immunotherapy.

Dual effects of radiotherapy on tumor microenvironment and its contribution towards the development of resistance to immunotherapy in gastrointestinal and thoracic cancers

Successful clinical methods for tumor elimination include a combination of surgical resection, radiotherapy, and chemotherapy. Radiotherapy is one of the crucial components of the cancer treatment regimens which allow to extend patient life expectancy. Current cutting-edge radiotherapy research is focused on the identification of methods that should increase cancer cell sensitivity to radiation and activate anti-cancer immunity mechanisms. Radiation treatment activates various cells of the tumor microenvironment (TME) and impacts tumor growth, angiogenesis, and anti-cancer immunity. Radiotherapy was shown to regulate signaling and anti-cancer functions of various TME immune and vasculature cell components, including tumor-associated macrophages, dendritic cells, endothelial cells, cancer-associated fibroblasts (CAFs), natural killers, and other T cell subsets. Dual effects of radiation, including metastasis-promoting effects and activation of oxidative stress, have been detected, suggesting that radiotherapy triggers heterogeneous targets. In this review, we critically discuss the activation of TME and angiogenesis during radiotherapy which is used to strengthen the effects of novel immunotherapy. Intracellular, genetic, and epigenetic mechanisms of signaling and clinical manipulations of immune responses and oxidative stress by radiotherapy are accented. Current findings indicate that radiotherapy should be considered as a supporting instrument for immunotherapy to limit the cancer-promoting effects of TME. To increase cancer-free survival rates, it is recommended to combine personalized radiation therapy methods with TME-targeting drugs, including immune checkpoint inhibitors.

SMYD2 inhibition-mediated hypomethylation of Ku70 contributes to impaired nonhomologous end joining repair and antitumor immunity

DNA damage repair (DDR) is a double-edged sword with different roles in cancer susceptibility and drug resistance. Recent studies suggest that DDR inhibitors affect immune surveillance. However, this phenomenon is poorly understood. We report that methyltransferase SMYD2 plays an essential role in nonhomologous end joining repair (NHEJ), driving tumor cells adaptive to radiotherapy. Mechanically, in response to DNA damage, SMYD2 is mobilized onto chromatin and methylates Ku70 at lysine-74, lysine-516, and lysine-539, leading to increased recruitment of Ku70/Ku80/DNA-PKcs complex. Knockdown of SMYD2 or its inhibitor AZ505 results in persistent DNA damage and improper repair, which sequentially leads to accumulation of cytosolic DNA, and activation of cGAS-STING pathway and triggers antitumor immunity via infiltration and activation of cytotoxic CD8⁺ T cells. Our study reveals an unidentified role of SMYD2 in regulating NHEJ pathway and innate immune responses, suggesting that SMYD2 is a promising therapeutic target for cancer treatment.

Radiotherapy and Immunotherapy in Lung Cancer

The emergence of immune checkpoint inhibitors (ICIs) as a pillar of cancer treatment has emphasized the immune system's integral role in tumor control and progression through cancer immune surveillance. ICIs are being investigated and incorporated into the treatment paradigm for lung cancers across stages and histology. To date, definitive concurrent chemoradiotherapy followed by consolidative durvalumab is the only National Comprehensive Cancer Network's recommended treatment paradigm including radiotherapy with ICI in lung cancers, although there are other recommendations for ICI with chemotherapy and/or surgery. This narrative review provides an overall view of the evolving integration and synergistic role of immunotherapy and radiotherapy and outlines the use of immunotherapy with radiotherapy for the management of small cell lung cancer and non-small cell lung cancer. It also reviews selected, practice-changing clinical trials that led to the current standard of care for lung cancers.

Incidence and risk factors for second malignancies among patients with myeloproliferative neoplasms

OBJECTIVE

The clinical characteristics and survival of patients with myeloproliferative neoplasms (MPNs) with secondary cancer were analyzed to explore the possible risk factors for secondary cancer in MPN patients.

METHODS

The clinical characteristics of 1060 Chinese patients with MPN were retrospectively analyzed. The Kaplan-Meier method was used to analyze the survival. The Cox multivariate regression model was used to analyze the risk factors for developing secondary cancer in patients with MPNs.

RESULTS

The 1060 patients with MPN had a median follow-up of 10 years (range 1-50) and a median age of 55 years (range 21-86), and 497 (45.2%) were male. The proportion of PV, ET, and PMF was 52.2%, 33.5%, and 14.3%, respectively. About 28.1% (298/1060) of 1060 MPN patients died. The median survival times of the PV, ET, and PMF groups were 20, 24, and 12 years, respectively (p < 0.0001). In age- and sex-matched healthy Chinese patients, the standardized incidence ratio (SIR) value of developing secondary cancer in MPN patients was 6.41 (95% CI: 4.90-9.48). The median survival time was 14 years in the MPN with secondary cancer group. The Cox multivariate analysis showed that age ≥ 65 years (p < 0.0001, HR = 5.027, 95% CI [2.823, 8.952]), MF-1 (p = 0.001, HR = 2.887, 95% CI [1.503, 5.545]) were risk factors for developing secondary cancer.

CONCLUSIONS

The survival of MPN patients with secondary cancer was significantly worse than that of patients without secondary cancer. Compared with normal subjects, MPN patients had a 6.41-fold increased risk of developing secondary cancer, and age ≥ 65 years and MF-1 were risk factors for developing secondary cancer in MPN patients.

The transcription factor IRF2 drives interferon-mediated CD8+ T cell exhaustion to restrict anti-tumor immunity

Type I and II interferons (IFNs) stimulate pro-inflammatory programs that are critical for immune activation, but also induce immune-suppressive feedback circuits that impede control of cancer growth. Here, we sought to determine how these opposing programs are differentially induced. We demonstrated that the transcription factor interferon regulatory factor 2 (IRF2) was expressed by many immune cells in the tumor in response to sustained IFN signaling. CD8+ T cell-specific deletion of IRF2 prevented acquisition of the T cell exhaustion program within the tumor and instead enabled sustained effector functions that promoted long-term tumor control and increased responsiveness to immune checkpoint and adoptive cell therapies. The long-term tumor control by IRF2-deficient CD8+ T cells required continuous integration of both IFN-I and IFN-II signals. Thus, IRF2 is a foundational feedback molecule that redirects IFN signals to suppress T cell responses and represents a potential target to enhance cancer control.

Micro-RNA193a-3p Inhibits Breast Cancer Cell Driven Growth of Vascular Endothelial Cells by Altering Secretome and Inhibiting Mitogenesis: Transcriptomic and Functional Evidence

Breast cancer (BC) cell secretome in the tumor microenvironment (TME) facilitates neo-angiogenesis by promoting vascular endothelial cell (VEC) growth. Drugs that block BC cell growth or angiogenesis can restrict tumor growth and are of clinical relevance. Molecules that can target both BC cell and VEC growth as well as BC secretome may be more effective in treating BC. Since small non-coding microRNAs (miRs) regulate cell growth and miR193a-3p has onco-suppressor activity, we investigated whether miR193a-3p inhibits MCF-7-driven growth (proliferation, migration, capillary formation, signal transduction) of VECs. Using BC cells and VECs grown in monolayers or 3D spheroids and gene microarrays, we demonstrate that: pro-growth effects of MCF-7 and MDA-MB231 conditioned medium (CM) are lost in CM collected from MCF-7/MDA-MB231 cells pre-transfected with miR193a-3p (miR193a-CM). Moreover, miR193a-CM inhibited MAPK and Akt phosphorylation in VECs. In microarray gene expression studies, miR193a-CM upregulated 553 genes and downregulated 543 genes in VECs. Transcriptomic and pathway enrichment analysis of differentially regulated genes revealed downregulation of interferon-associated genes and pathways that induce angiogenesis and BC/tumor growth. An angiogenesis proteome array confirmed the downregulation of 20 pro-angiogenesis proteins by miR193a-CM in VECs. Additionally, in MCF-7 cells and VECs, estradiol (E2) downregulated miR193a-3p expression and induced growth. Ectopic expression of miR193a-3p abrogated the growth stimulatory effects of estradiol E2 and serum in MCF-7 cells and VECs, as well as in MCF-7 and MCF-7+VEC 3D spheroids. Immunostaining of MCF-7+VEC spheroid sections with ki67 showed miR193a-3p inhibits cell proliferation. Taken together, our findings provide first evidence that miR193a-3p abrogates MCF-7-driven growth of VECs by altering MCF-7 secretome and downregulating pro-growth interferon signals and proangiogenic proteins. Additionally, miR193a-3p inhibits serum and E2-induced growth of MCF-7, VECs, and MCF-7+VEC spheroids. In conclusion, miRNA193a-3p can potentially target/inhibit BC tumor angiogenesis via a dual mechanism: (1) altering proangiogenic BC secretome/TME and (2) inhibiting VEC growth. It may represent a therapeutic molecule to target breast tumor growth.

E2F1 Affects the Therapeutic Response to Neoadjuvant Therapy in Breast Cancer

This study is aimed at screening genes for predicting the sensitivity response and favorable outcome of neoadjuvant therapy in breast cancer. We downloaded neoadjuvant therapy genetic data of breast cancer and separated it into the pathological complete response (pCR) group and the non-pCR group. Differential expression analysis was performed to select the differentially expressed genes (DEGs). After that, we investigated the enriched biological processes and pathways of DEGs. Then, core up/down protein-protein interaction (PPI) network was, respectively, constructed to identify the hub genes. A transcription factor-target gene regulation network was built to screen core transcription factors (TFs). We found one upregulated DEG (KLHDC7B) and four downregulated DEGs (TFF1, LOC440335, SLC39A6, and MLPH) overlapped in three datasets. All DEGs were mainly enriched in pathways related to DNA biosynthesis, cell cycle, immune response, metabolism, and angiogenesis. The hub genes were KRT18, IL7R, HIST1H1A, and E2F1. The core TFs were HOXA9, SPDEF, FOXA1, E2F1, and PGR. RT-qPCR suggested that E2F1 was overexpressed in MCF-7, but HOXA9 was low-expressed. Western blot suggested that the MAPK signal pathway was inhibited in MCF-7/ADR. That is to say, some genes and core TFs can predict the sensitivity response of neoadjuvant therapy in breast cancer. And E2F1 may be involved in the process of drug resistance by regulating the MAPK signaling pathway. These might be useful as sensitive genes for the efficacy evaluation of neoadjuvant chemotherapy in breast cancer.

Apoptotic caspase inhibits innate immune signaling by cleaving NF-κBs in both Mammals and Flies

Host organisms use different innate immune mechanisms to defend against pathogenic infections, while tight control of innate immunity is essential for proper immune induction and balance. Here, we reported that apoptotic induction or caspase-3 overexpression caused dramatic reduction of differently triggered cytokine signalings in human cells, murine primary cells and mouse model, while the loss of caspase-3 or inhibiting apoptosis markedly enhances these immune signalings. Furthermore, caspase-3 can mediate the cleavage of NF-κB members p65/RelA, RelB, and c-Rel via its protease activity. And the caspase-3-resistant p65/RelA, RelB, or c-Rel mutant mostly restored the caspase-3-induced suppression of cytokine production. Interestingly, we further uncovered that apoptotic induction also dramatically inhibited Toll immune signaling in Drosophila, and the Drosophila effector caspases, drICE and DCP-1, also mediated the degradation of DIF, the NF-κB of Toll signaling. Together, our findings demonstrate apoptotic effector caspases, including mammalian caspase-3 and fly drICE/DCP-1, can function as repressors of NF-κB-mediated innate immune signalings.

Targeting PARP11 to avert immunosuppression and improve CAR T therapy in solid tumors

Evasion of antitumor immunity and resistance to therapies in solid tumors are aided by an immunosuppressive tumor microenvironment (TME). We found that TME factors, such as regulatory T cells and adenosine, downregulated type I interferon receptor IFNAR1 on CD8⁺ cytotoxic T lymphocytes (CTLs). These events relied upon poly-ADP ribose polymerase-11 (PARP11), which was induced in intratumoral CTLs and acted as a key regulator of the immunosuppressive TME. Ablation of PARP11 prevented loss of IFNAR1, increased CTL tumoricidal activity and inhibited tumor growth in an IFNAR1-dependent manner. Accordingly, genetic or pharmacologic inactivation of PARP11 augmented the therapeutic benefits of chimeric antigen receptor T cells. Chimeric antigen receptor CTLs engineered to inactivate PARP11 demonstrated a superior efficacy against solid tumors. These findings highlight the role of PARP11 in the immunosuppressive TME and provide a proof of principle for targeting this pathway to optimize immune therapies.

EMT alterations in the solute carrier landscape uncover SLC22A10/A15 imposed vulnerabilities in pancreatic cancer

The involvement of membrane-bound solute carriers (SLCs) in neoplastic transdifferentiation processes is poorly defined. Here, we examined changes in the SLC landscape during epithelial-mesenchymal transition (EMT) of pancreatic cancer cells. We show that two SLCs from the organic anion/cation transporter family, SLC22A10 and SLC22A15, favor EMT via interferon (IFN) α and γ signaling activation of receptor tyrosine kinase-like orphan receptor 1 (ROR1) expression. In addition, SLC22A10 and SLC22A15 allow tumor cell accumulation of glutathione to support EMT via the IFNα/γ-ROR1 axis. Moreover, a pan-SLC22A inhibitor lesinurad reduces EMT-induced metastasis and gemcitabine chemoresistance to prolong survival in mouse models of pancreatic cancer, thus identifying new vulnerabilities for human PDAC.

The oncoprotein BCL6 enables solid tumor cells to evade genotoxic stress

Genotoxic agents remain the mainstay of cancer treatment. Unfortunately, the clinical benefits are often countered by a rapid tumor adaptive response. Here, we report that the oncoprotein B cell lymphoma 6 (BCL6) is a core component that confers solid tumor adaptive resistance to genotoxic stress. Multiple genotoxic agents promoted BCL6 transactivation, which was positively correlated with a weakened therapeutic efficacy and a worse clinical outcome. Mechanistically, we discovered that treatment with the genotoxic agent etoposide led to the transcriptional reprogramming of multiple pro-inflammatory cytokines, among which the interferon-α and interferon-γ responses were substantially enriched in resistant cells. Our results further revealed that the activation of interferon/signal transducer and activator of transcription 1 axis directly upregulated BCL6 expression. The increased expression of BCL6 further repressed the tumor suppressor PTEN and consequently enabled resistant cancer cell survival. Accordingly, targeted inhibition of BCL6 remarkably enhanced etoposide-triggered DNA damage and apoptosis both in vitro and in vivo. Our findings highlight the importance of BCL6 signaling in conquering solid tumor tolerance to genotoxic stress, further establishing a rationale for a combined approach with genotoxic agents and BCL6-targeted therapy.

Tumor-derived extracellular vesicles regulate tumor-infiltrating regulatory T cells via the inhibitory immunoreceptor CD300a

Although tumor-infiltrating regulatory T (Treg) cells play a pivotal role in tumor immunity, how Treg cell activation are regulated in tumor microenvironments remains unclear. Here, we found that mice deficient in the inhibitory immunoreceptor CD300a on their dendritic cells (DCs) have increased numbers of Treg cells in tumors and greater tumor growth compared with wild-type mice after transplantation of B16 melanoma. Pharmacological impairment of extracellular vesicle (EV) release decreased Treg cell numbers in CD300a-deficient mice. Coculture of DCs with tumor-derived EV (TEV) induced the internalization of CD300a and the incorporation of EVs into endosomes, in which CD300a inhibited TEV-mediated TLR3–TRIF signaling for activation of the IFN-β-Treg cells axis. We also show that higher expression of CD300A was associated with decreased tumor-infiltrating Treg cells and longer survival time in patients with melanoma. Our findings reveal the role of TEV and CD300a on DCs in Treg cell activation in the tumor microenvironment.

Radiotherapy and immunotherapy: open questions and future strategies

Immune checkpoint blockade (ICB) improves outcomes for some patients with advanced or metastatic cancers. Despite demonstrable progress, many patients do not respond to ICB. Recently, clinical trials have focused on combinations of ICB with radiation therapy. Although two recent Phase III randomized trials demonstrated improved survival with adjuvant ICB following chemoradiation, other Phase I/II/III trials are either negative or inconclusive, but do yield suggestive results and promising insights into future therapeutic strategies. We provide a selective review of a subset of these trials and attempt to integrate with basic laboratory findings where relevant to define issues pertaining to the combination of radiotherapy and immunotherapy.

In vivo CRISPR screens identify the E3 ligase Cop1 as a modulator of macrophage infiltration and cancer immunotherapy target

Despite remarkable clinical efficacy of immune checkpoint blockade (ICB) in cancer treatment, ICB benefits for triple-negative breast cancer (TNBC) remain limited. Through pooled in vivo CRISPR knockout (KO) screens in syngeneic TNBC mouse models, we found that deletion of the E3 ubiquitin ligase Cop1 in cancer cells decreases secretion of macrophage-associated chemokines, reduces tumor macrophage infiltration, enhances anti-tumor immunity, and strengthens ICB response. Transcriptomics, epigenomics, and proteomics analyses revealed that Cop1 functions through proteasomal degradation of the C/ebpδ protein. The Cop1 substrate Trib2 functions as a scaffold linking Cop1 and C/ebpδ, which leads to polyubiquitination of C/ebpδ. In addition, deletion of the E3 ubiquitin ligase Cop1 in cancer cells stabilizes C/ebpδ to suppress expression of macrophage chemoattractant genes. Our integrated approach implicates Cop1 as a target for improving cancer immunotherapy efficacy in TNBC by regulating chemokine secretion and macrophage infiltration in the tumor microenvironment.

RNF2 ablation reprograms the tumor-immune microenvironment and stimulates durable NK and CD4+ T-cell-dependent antitumor immunity

Expanding the utility of immune-based cancer treatments is a clinical challenge due to tumor-intrinsic factors that suppress the immune response. Here we report the identification of tumoral ring finger protein 2 (RNF2), the core subunit of polycomb repressor complex 1, as a negative regulator of antitumor immunity in various human cancers, including breast cancer. In syngeneic murine models of triple-negative breast cancer, we found that deleting genes encoding the polycomb repressor complex 1 subunits Rnf2, BMI1 proto-oncogene, polycomb ring finger (Bmi1), or the downstream effector of Rnf2, remodeling and spacing factor 1 (Rsf1), was sufficient by itself to induce durable tumor rejection and establish immune memory by enhancing infiltration and activation of natural killer and CD4⁺ T cells, but not CD8⁺ T cells, into the tumor and enabled their cooperativity. These findings uncover an epigenetic reprogramming of the tumor-immune microenvironment, which fosters durable antitumor immunity and memory.

Actin Cytoskeleton Dynamics and Type I IFN-Mediated Immune Response: A Dangerous Liaison in Cancer?

Simple Summary

Actin cytoskeleton is a dynamic subcellular component critical for maintaining cell shape and for elaborating response to any stimulus converging on the cell. Cytoskeleton constantly interfaces with diverse cellular components and affects a wide range of processes important in homeostasis and disease. What has been clearly demonstrated to date is that pathogens modify and use host cytoskeleton to their advantage. What is now emerging is that in sterile conditions, when a chronic inflammation occurs as in cancer, the subversion of tissue homeostasis induces an alarm status which mimics infection. This activates cellular players similar to those that solve an infection, but their persistence may pave the way for tumor progression. Understanding molecular mechanisms engaged by cytoskeleton to induce this viral mimicry could improve our knowledge of processes governing tumor progression and resistance to therapy.

Abstract

Chronic viral infection and cancer are closely inter-related and are both characterized by profound alteration of tissue homeostasis. The actin cytoskeleton dynamics highly participate in tissue homeostasis and act as a sensor leading to an immune-mediated anti-cancer and anti-viral response. Herein we highlight the crucial role of actin cytoskeleton dynamics in participating in a viral mimicry activation with profound effect in anti-tumor immune response. This still poorly explored field understands the cytoskeleton dynamics as a platform of complex signaling pathways which may regulate Type I IFN response in cancer. This emerging network needs to be elucidated to identify more effective anti-cancer strategies and to further advance the immuno-oncology field which has revolutionized the cancer treatment. For a progress to occur in this exciting arena we have to shed light on actin cytoskeleton related pathways and immune response. Herein we summarize the major findings, considering the double sword of the immune response and in particular the role of Type I IFN pathways in resistance to anti-cancer treatment.

Type I Interferon Response in Radiation-Induced Anti-Tumor Immunity

The anti-tumor activity of interferons (IFNs) was first appreciated about half a century ago, and IFN-α2 was the first cancer immunotherapy approved by the US Food and Drug Administration. Radiation therapy (RT), one of the pillars of cancer treatment, directly causes DNA damage, which can lead to senescence and cell death in tumor cells. In recent years, however, RT-induced immunomodulatory effects have been recognized to play an indispensable role in achieving the optimum therapeutic effect of RT. Increasing evidence indicates that RT enhances adaptive anti-tumor immunity by augmenting the innate immune sensing of tumors in a type I IFN-dependent matter. This review briefly introduces the role of type I interferon in cancer and the available evidence on the overall effects of RT on tumor immunity mediated via type I IFN. Recent advances in deciphering the molecular mechanisms underlying the induction of type I IFNs triggered by RT, their clinical implications, and therapeutic opportunities will be highlighted.

Combining Radiation with Immunotherapy: The University of Pennsylvania Experience

Immune checkpoint inhibitors have shown remarkable clinical benefit across a variety of cancer types. However, the majority of patients do not respond or develop relapse after therapy. Radiation can favorably modulate the immune system and enhance tumor antigen recognition and rejection. Thus, the combination of radiation and immune checkpoint blockade (ICB) has been recognized as a promising strategy to improve tumor response and broaden the clinical utility of immunotherapy. In this review, we highlight the preclinical and clinical experience at our institution aimed at understanding and promoting the immunostimulatory effect of radiation. We discuss the rationale, design, results, and lessons from our clinical trials in combining radiation with anti-CTLA4 and/or anti-PD-1 therapy. In parallel, our studies to understand the resistance mechanism to radiation and ICB have converged on interferon (IFN) signaling as a key regulatory pathway. Persistent IFN-γ signaling impairs anti-tumor immune responses which can be reversed by using JAK inhibitor to disrupt the IFN signaling. Lastly we discuss remaining challenges, ongoing studies, and future directions in combining radiation with immunotherapy.

The Yin and Yang of Type I IFNs in Cancer Promotion and Immune Activation

Type I Interferons (IFNs) are key regulators of natural and therapy-induced host defense against viral infection and cancer. Several years of remarkable progress in the field of oncoimmunology have revealed the dual nature of these cytokines. Hence, Type I IFNs may trigger anti-tumoral responses, while leading immune dysfunction and disease progression. This dichotomy relies on the duration and intensity of the transduced signaling, the nature of the unleashed IFN stimulated genes, and the subset of responding cells. Here, we discuss the role of Type I IFNs in the evolving relationship between the host immune system and cancer, as we offer a view of the therapeutic strategies that exploit and require an intact Type I IFN signaling, and the role of these cytokines in inducing adaptive resistance. A deep understanding of the complex, yet highly regulated, network of Type I IFN triggered molecular pathways will help find a timely and immune"logical" way to exploit these cytokines for anticancer therapy.

Double-edged effects of interferons on the regulation of cancer-immunity cycle

Interferons (IFNs) are a large family of pleiotropic cytokines that regulate both innate and adaptive immunity and show anti-cancer effects in various cancer types. Moreover, it was revealed that IFN signaling plays critical roles in the success of cancer therapy strategies, thereby enhancing their therapeutic effects. However, IFNs have minimal or even adverse effects on cancer eradication, and mediate cancer immune escape in some instances. Thus, IFNs have a double-edged effect on the cancer immune response. Recent studies suggest that IFNs regulate each step of the cancer immunity-cycle, consisting of cancer antigen release, presentation of antigens and activation of T cells, trafficking and infiltration of effector T cells into the tumor microenvironment, and recognition and killing of cancer cells, which contributes to our understanding of the mechanisms of IFNs in regulating cancer immunity. In this review, we focus on IFNs and cancer immunity and elaborate on the roles of IFNs in regulating the cancer-immunity cycle.

A Review of Repurposed Cancer Drugs in Clinical Trials for Potential Treatment of COVID-19

The pandemic of the coronavirus disease 2019 (COVID-19) represents an unprecedented challenge to identify effective drugs for prevention and treatment. While the world’s attention is focused on news of COVID-19 vaccine updates, clinical management still requires improvement. Due to the similarity of cancer-induced inflammation, immune dysfunction, and coagulopathy to COVID-19, anticancer drugs, such as Interferon, Pembrolizumab or Bicalutamide, are already being tested in clinical trials for repurposing, alone or in combination. Given the rapid pace of scientific discovery and clinical data generated by the large number of people rapidly infected, clinicians need effective medical treatments for this infection.

Tumor interferon signaling and suppressive myeloid cells are associated with CAR T-cell failure in large B-cell lymphoma

Axicabtagene ciloleucel (axi-cel) is a chimeric antigen receptor (CAR) T-cell therapy for relapsed or refractory large B-cell lymphoma (LBCL). This study evaluated whether immune dysregulation, present before CAR T-cell therapy, was associated with treatment failure. Tumor expression of interferon (IFN) signaling, high blood levels of monocytic myeloid-derived suppressor cells (M-MDSCs), and high blood interleukin-6 and ferritin levels were each associated with a lack of durable response. Similar to other cancers, we found that in LBCL tumors, IFN signaling is associated with the expression of multiple checkpoint ligands, including programmed cell death-ligand 1, and these were higher in patients who lacked durable responses to CAR-T therapy. Moreover, tumor IFN signaling and blood M-MDSCs associated with decreased axi-cel expansion. Finally, patients with high tumor burden had higher immune dysregulation with increased serum inflammatory markers and tumor IFN signaling. These data support that immune dysregulation in LBCL promotes axi-cel resistance via multiple mechanistic programs: insufficient axi-cel expansion associated with both circulating M-MDSC and tumor IFN signaling, which also gives rise to expression of immune checkpoint ligands.

Functional Interfaces, Biological Pathways, and Regulations of Interferon-Related DNA Damage Resistance Signature (IRDS) Genes

Interferon (IFN)-related DNA damage resistant signature (IRDS) genes are a subgroup of interferon-stimulated genes (ISGs) found upregulated in different cancer types, which promotes resistance to DNA damaging chemotherapy and radiotherapy. Along with briefly discussing IFNs and signalling in this review, we highlighted how different IRDS genes are affected by viruses. On the contrary, different strategies adopted to suppress a set of IRDS genes (STAT1, IRF7, OAS family, and BST2) to induce (chemo- and radiotherapy) sensitivity were deliberated. Significant biological pathways that comprise these genes were classified, along with their frequently associated genes (IFIT1/3, IFITM1, IRF7, ISG15, MX1/2 and OAS1/3/L). Major upstream regulators from the IRDS genes were identified, and different IFN types regulating these genes were outlined. Functional interfaces of IRDS proteins with DNA/RNA/ATP/GTP/NADP biomolecules featured a well-defined pharmacophore model for STAT1/IRF7-dsDNA and OAS1/OAS3/IFIH1-dsRNA complexes, as well as for the genes binding to GDP or NADP+. The Lys amino acid was found commonly interacting with the ATP phosphate group from OAS1/EIF2AK2/IFIH1 genes. Considering the premise that targeting IRDS genes mediated resistance offers an efficient strategy to resensitize tumour cells and enhances the outcome of anti-cancer treatment, this review can add some novel insights to the field.

The BRCA1 Pseudogene Negatively Regulates Antitumor Responses through Inhibition of Innate Immune Defense Mechanisms

Innate immune defense mechanisms play a pivotal role in antitumor responses. Recent evidence suggests that antiviral innate immunity is regulated not only by exogenous non-self-RNA but also by host-derived pseudogene RNAs. A growing body of evidence also indicates a biological role for pseudogenes as gene expression regulators or immune modulators. Here, we report an important role for BRCA1P1, the pseudogene of the BRCA1 tumor-suppressor gene, in regulating innate immune defense mechanisms in breast cancer cells. BRCA1P1 expresses a long-noncoding RNA (lncRNA) in breast cancer cells through divergent transcription. Expression of lncRNA-BRCA1P1 is increased in breast tumors compared with normal breast tissues. Depletion of BRCA1P1 induces an antiviral defense-like program, including the expression of antiviral genes in breast cancer cells. Furthermore, BRCA1P1-deficient cancer cells mimic virus-infected cells by stimulating cytokines and inducing cell apoptosis. Accordingly, depletion of BRCA1P1 increases host innate immune responses and restricts virus replication. In converse, overexpression of BRCA1P1 reduces cytokine expression in breast cancer cells. Mechanistically, lncRNA-BRCA1P1 is localized in the nucleus, binds to the NF-κB subunit RelA, and negatively regulates antiviral gene expression. Finally, in a xenograft mouse model of breast cancer, depletion of BRCA1P1 stimulates cytokine expression and local immunity, and suppresses tumor growth. Our results suggest an important role for BRCA1P1 in innate immune defense mechanisms and antitumor responses. This mechanism of antiviral immunity regulated by a host-derived pseudogene RNA may guide the development of novel therapies targeting immune responses in breast cancer. SIGNIFICANCE: This study identifies a novel mechanism of innate immunity driven by a host pseudogene RNA that inhibits innate immune defense mechanisms and antitumor responses through regulation of antiviral gene expression.

Immune Escape in Prostate Cancer: Known and Predicted Mechanisms and Targets

Complex immune evasion mechanisms and lack of biomarkers predicting responsiveness to immune checkpoint blockade therapies compromise immunotherapy's therapeutic efficacy for patients with prostate cancer. The authors review established and nominated immune evasion mechanisms in prostate cancer and discuss how the precise treatment strategies can be developed to improve efficacy of immunotherapy.

Interferons in cancer immunoediting: sculpting metastasis and immunotherapy response

Interferons (IFNs) are pleiotropic cytokines critical for regulation of epithelial cell functions and for immune system regulation. In cancer, IFNs contribute to tumor-intrinsic and -extrinsic mechanisms that determine the quality of antitumor immunity and response to immunotherapy. In this Review, we focus on the different types of tumor IFN sensitivity that determine dynamic tumor-immune interactions and their coevolution during cancer progression and metastasis. We extend the discussion to new evidence supporting immunotherapy-mediated immunoediting and the dual opposing roles of IFNs that lead to immune checkpoint blockade response or resistance. Understanding the intricate dynamic responses to IFN will lead to novel immunotherapeutic strategies to circumvent protumorigenic effects of IFN while exploiting IFN-mediated antitumor immunity.

Type I interferons in pancreatic cancer and development of new therapeutic approaches

Immunotherapy has emerged as a new treatment strategy for cancer. However, its promise in pancreatic cancer has not yet been realized. Understanding the immunosuppressive tumor microenvironment of pancreatic cancer, and identifying new therapeutic targets to increase tumor-specific immune responses, is necessary in order to improve clinical outcomes. Type I interferons, e.g. IFN-α and -β, are considered as an important bridge between the innate and adaptive immune system. Thereby, type I IFNs induce a broad spectrum of anti-tumor effects, including immunologic, vascular, as well as direct anti-tumor effects. While IFN therapies have been around for a while, new insights into exogenous and endogenous activation of the IFN pathway have resulted in new IFN-related cancer treatment strategies. Here, we focus on the pre-clinical and clinical evidence of novel ways to take advantage of the type I IFN pathway, such as IFN based conjugates and activation of the STING and RIG-I pathways.

Interferon-lambda (IFNL) germline variations and their significance for HCC and PDAC progression: an analysis of The Cancer Genome Atlas (TCGA) data

BACKGROUND

Hepatocellular carcinoma (HCC) and pancreatic ductal adenocarcinoma (PDAC) are malignancies with a leading lethality. With reference to interferons (IFNs) known to mediate antitumor activities, this study investigated the relationship between germline genetic variations in type III IFN genes and cancer disease progression from The Cancer Genome Atlas (TCGA) data. The genetic variations under study tag a gain-or-loss-of-function dinucleotide polymorphism within the IFNL4 gene, rs368234815 [TT/ΔG].

METHODS

The entirety of the TCGA sequencing data was used to assess genotypes of 187 patients with HCC and of 162 patients with PDAC matched for ethnicity. Stratified for IFNL genotypes, both cohorts were subjected to time-to-event analyses according to Kaplan-Meier with regard to the length of the specific progression free interval (PFI) and the overall survival (OS) time as two clinical endpoints for disease progression.

RESULTS

Logrank analysis revealed a significant relationship between IFNL genotypes and disease outcome for PDAC. This relationship was not found for HCC. A multiple Cox regression analysis employing patients' age, tumor grade and tumor stage as further covariates proved IFNL genotypes to be independent predictors for PDAC disease outcome.

CONCLUSION

This repository-based approach unveiled clinical evidence suggestive for an impact of IFNL germline variations for PDAC progression with an IFNL haplotype predisposing for IFNL4 expression being favorable.

Clonal tracing reveals diverse patterns of response to immune checkpoint blockade

BACKGROUND

Immune checkpoint blockade (ICB) therapy has improved patient survival in a variety of cancers, but only a minority of cancer patients respond. Multiple studies have sought to identify general biomarkers of ICB response, but elucidating the molecular and cellular drivers of resistance for individual tumors remains challenging. We sought to determine whether a tumor with defined genetic background exhibits a stereotypic or heterogeneous response to ICB treatment.

RESULTS

We establish a unique mouse system that utilizes clonal tracing and mathematical modeling to monitor the growth of each cancer clone, as well as the bulk tumor, in response to ICB. We find that tumors derived from the same clonal populations showed heterogeneous ICB response and diverse response patterns. Primary response is associated with higher immune infiltration and leads to enrichment of pre-existing ICB-resistant cancer clones. We further identify several cancer cell-intrinsic gene expression signatures associated with ICB resistance, including increased interferon response genes and glucocorticoid response genes. These findings are supported by clinical data from ICB treatment cohorts.

CONCLUSIONS

Our study demonstrates diverse response patterns from the same ancestor cancer cells in response to ICB. This suggests the value of monitoring clonal constitution and tumor microenvironment over time to optimize ICB response and to design new combination therapies. Furthermore, as ICB response may enrich for cancer cell-intrinsic resistance signatures, this can affect interpretations of tumor RNA-seq data for response-signature association studies.

Aggressive PDACs Show Hypomethylation of Repetitive Elements and the Execution of an Intrinsic IFN Program Linked to a Ductal Cell of Origin

Pancreatic ductal adenocarcinoma (PDAC) is characterized by extensive desmoplasia, which challenges the molecular analyses of bulk tumor samples. Here we FACS-purified epithelial cells from human PDAC and normal pancreas and derived their genome-wide transcriptome and DNA methylome landscapes. Clustering based on DNA methylation revealed two distinct PDAC groups displaying different methylation patterns at regions encoding repeat elements. Methylation^low tumors are characterized by higher expression of endogenous retroviral transcripts and double-stranded RNA sensors, which lead to a cell-intrinsic activation of an interferon signature (IFNsign). This results in a protumorigenic microenvironment and poor patient outcome. Methylation^low/IFNsign^high and Methylation^high/IFNsign^low PDAC cells preserve lineage traits, respective of normal ductal or acinar pancreatic cells. Moreover, ductal-derived Kras ^G12D/Trp53 ^-/- mouse PDACs show higher expression of IFNsign compared with acinar-derived counterparts. Collectively, our data point to two different origins and etiologies of human PDACs, with the aggressive Methylation^low/IFNsign^high subtype potentially targetable by agents blocking intrinsic IFN signaling. SIGNIFICANCE: The mutational landscapes of PDAC alone cannot explain the observed interpatient heterogeneity. We identified two PDAC subtypes characterized by differential DNA methylation, preserving traits from normal ductal/acinar cells associated with IFN signaling. Our work suggests that epigenetic traits and the cell of origin contribute to PDAC heterogeneity.This article is highlighted in the In This Issue feature, p. 521.

Type I interferons and related pathways in cell senescence

This review article addresses the largely unanticipated convergence of two landmark discoveries. The first is the discovery of interferons, critical signaling molecules for all aspects of both innate and adaptive immunity, discovered originally by Isaacs and Lindenmann at the National Institute for Medical Research, London, in 1957 (Proceedings of the Royal Society of London. Series B: Biological Sciences, 1957, 147, 258). The second, formerly unrelated discovery, by Leonard Hayflick and Paul Moorhead (Wistar Institute, Philadelphia) is that cultured cells undergo an irreversible but viable growth arrest, termed senescence, after a finite and predictable number of cell divisions (Experimental Cell Research, 1961, 25, 585). This phenomenon was suspected to relate to organismal aging, which was confirmed subsequently (Nature, 2011, 479, 232). Cell senescence has broad‐ranging implications for normal homeostasis, including immunity, and for diverse disease states, including cancer progression and response to therapy (Nature Medicine, 2015, 21, 1424; Cell, 2019, 179, 813; Cell, 2017, 169, 1000; Trends in Cell Biology, 2018, 28, 436; Journal of Cell Biology, 2018, 217, 65). Here, we critically address the bidirectional interplay between interferons (focusing on type I) and cell senescence, with important implications for health and healthspan.

The Relationship Between Protein S-Nitrosylation and Human Diseases: A Review

S-nitrosylation (SNO) is a covalent post-translational oxidative modification. The reaction is the nitroso group (-NO) to a reactive cysteine thiol within a protein to form the SNO. In recent years, a variety of proteins in human body have been found to undergo thiol nitrosylation under specific conditions. Protein SNO, which is closely related to cardiovascular disease, Parkinson's syndrome, Alzheimer's disease and tumors, plays an important role in regulatory mechanism of protein function in both physiological and pathological pathways, such as in cellular homeostasis and metabolism. This review discusses possible molecular mechanisms protein SNO modification, such as the role of NO in vivo and the formation mechanism of SNO, with particular emphasis on mechanisms utilized by SNO to cause certain diseases of human. Importantly, the effect of SNO on diseases is multifaceted and multi-channel, and its critical value in vivo is not well defined. Intracellular redox environment is also a key factor affecting its level. Therefore, we should pay more attention to the equilibrium relationship between SNO and denitrosylation pathway in the future researches. These findings provide theoretical support for the improvement or treatment of diseases from the point of view of SNO.

Tackling Resistance to Cancer Immunotherapy: What Do We Know?

Cancer treatment has evolved tremendously in the last few decades. Immunotherapy has been considered to be the forth pillar in cancer treatment in addition to conventional surgery, radiotherapy, and chemotherapy. Though immunotherapy has resulted in impressive response, it is generally limited to a small subset of patients. Understanding the mechanisms of resistance toward cancer immunotherapy may shed new light to counter that resistance. In this review, we highlighted and summarized two major hurdles (recognition and attack) of cancer elimination by the immune system. The mechanisms of failure of some available immunotherapy strategies were also described. Moreover, the significance role of immune compartment for various established cancer treatments were also elucidated in this review. Then, the mechanisms of combinatorial treatment of various conventional cancer treatment with immunotherapy were discussed. Finally, a strategy to improve immune cancer killing by characterizing cancer immune landscape, then devising treatment based on that cancer immune landscape was put forward.

RIG-I-like receptors: their regulation and roles in RNA sensing

Retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) are key sensors of virus infection, mediating the transcriptional induction of type I interferons and other genes that collectively establish an antiviral host response. Recent studies have revealed that both viral and host-derived RNAs can trigger RLR activation; this can lead to an effective antiviral response but also immunopathology if RLR activities are uncontrolled. In this Review, we discuss recent advances in our understanding of the types of RNA sensed by RLRs in the contexts of viral infection, malignancies and autoimmune diseases. We further describe how the activity of RLRs is controlled by host regulatory mechanisms, including RLR-interacting proteins, post-translational modifications and non-coding RNAs. Finally, we discuss key outstanding questions in the RLR field, including how our knowledge of RLR biology could be translated into new therapeutics.

Interferons: role in cancer therapy

Interferons (IFNs) are a group of signaling cytokines, secreted by host cells to induce protection against various disorders. IFNs can directly impact on tumor cells or indirectly induce the immune system to protect host cells. The expression levels of IFNs and its functions of are excellently modulated in a way to protect host cells from probable toxicities caused by extreme responses. The efficacy of anticancer therapies is correlated to IFNs signaling. Although IFN signaling is involved in induction of antitumor responses, chronic stimulation of the IFN signaling pathway can induce resistance to various antineoplasm therapies. Hence, IFNs are expressed by both cancer and immune cells, and modulate their biological function. Understanding this mechanism of action might be a key target of combination therapies.

Cancer Immune Therapy for Philadelphia Chromosome-Negative Chronic Myeloproliferative Neoplasms

Philadelphia chromosome-negative chronic myeloproliferative neoplasms (MPN) are neoplastic diseases of the hematopoietic stem cells in the bone marrow. MPN are characterized by chronic inflammation and immune dysregulation. Of interest, the potent immunostimulatory cytokine interferon-α has been used to treat MPN for decades. A deeper understanding of the anti-cancer immune response and of the different immune regulatory mechanisms in patients with MPN has paved the way for an increased perception of the potential of cancer immunotherapy in MPN. Therapeutic vaccination targeting the driver mutations in MPN is one recently described potential new treatment modality. Furthermore, T cells can directly react against regulatory immune cells because they recognize proteins like arginase and programmed death ligand 1 (PD-L1). Therapeutic vaccination with arginase or PD-L1 therefore offers a novel way to directly affect immune inhibitory pathways, potentially altering tolerance to tumor antigens like mutant CALR and mutant JAK2. Other therapeutic options that could be used in concert with therapeutic cancer vaccines are immune checkpoint-blocking antibodies and interferon-α. For more advanced MPN, adoptive cellular therapy is a potential option that needs more preclinical investigation. In this review, we summarize current knowledge about the immune system in MPN and discuss the many opportunities for anti-cancer immunotherapy in patients with MPN.

miR-181a initiates and perpetuates oncogenic transformation through the regulation of innate immune signaling

Genomic instability (GI) predisposes cells to malignant transformation, however the molecular mechanisms that allow for the propagation of cells with a high degree of genomic instability remain unclear. Here we report that miR-181a is able to transform fallopian tube secretory epithelial cells through the inhibition of RB1 and stimulator-of-interferon-genes (STING) to propagate cells with a high degree of GI. MiR-181a targeting of RB1 leads to profound nuclear defects and GI generating aberrant cytoplasmic DNA, however simultaneous miR-181a mediated inhibition of STING allows cells to bypass interferon mediated cell death. We also found that high miR-181a is associated with decreased IFNγ response and lymphocyte infiltration in patient tumors. DNA oncoviruses are the only known inhibitors of STING that allow for cellular transformation, thus, our findings are the first to identify a miRNA that can downregulate STING expression to suppress activation of intrinsic interferon signaling. This study introduces miR-181a as a putative biomarker and identifies the miR-181a-STING axis as a promising target for therapeutic exploitation.

Clinicopathological and prognostic significance and molecular mechanisms governing uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Although UM and cutaneous melanoma are derived from melanocytes, UM differs clinically and biologically from its more common skin counterparts. More than half of primary UMs metastasize. However, there is currently no effective treatment for metastatic UM. Therefore, studying mutations related to the metastasis, growth, proliferation, and survival of UM can help researchers understand its pathogenesis and metastatic mechanism, thereby leading to a more effective treatment. In addition, we provide an overview of the recent basic and clinical studies to provide a strong foundation for developing novel anti-carcinogenesis targets for future interventions.

Biological Factors behind Melanoma Response to Immune Checkpoint Inhibitors

Modern immunotherapy together with targeted therapy has revolutionized the treatment of advanced melanoma. Inhibition of immune checkpoints significantly improved the median overall survival and gave hope to many melanoma patients. However, this treatment has three serious drawbacks: high cost, serious side effects, and an effectiveness limited only to approximately 50% of patients. Some patients do not derive any or short-term benefit from this treatment due to primary or secondary resistance. The response to immunotherapy depends on many factors that fall into three main categories: those associated with melanoma cells, those linked to a tumor and its microenvironment, and those classified as individual ontogenic and physiological features of the patient. The first category comprises expression of PD-L1 and HLA proteins on melanoma cells as well as genetic/genomic metrics such as mutational load, (de)activation of specific signaling pathways and epigenetic factors. The second category is the inflammatory status of the tumor: “hot” versus “cold” (i.e., high versus low infiltration of immune cells). The third category comprises metabolome and single nucleotide polymorphisms of specific genes. Here we present up-to-date data on those biological factors influencing melanoma response to immunotherapy with a special focus on signaling pathways regulating the complex process of anti-tumor immune response. We also discuss their potential predictive capacity.

[Immunotherapy in head and neck squamous cell carcinoma : Abscopal effects in combination with radiotherapy, extraordinary responses in combination with chemotherapy, and pseudoprogression]

BACKGROUND

The clinical implementation of immunotherapy has broadened the therapeutic options for recurrent and/or metastatic head and neck squamous cell carcinoma (HNSCC). Until 2016, the only molecularly targeted therapy was epidermal growth factor receptor (EGFR) blockade. However, immune checkpoint inhibition has recently become part of first-line treatment in recurrent and/or metastatic HNSCC.

OBJECTIVES

The occurrence of abscopal effects of radiotherapy and synergisms between immunotherapy and chemotherapy as well as the phenomenon of pseudoprogression in HNSCC were investigated.

MATERIALS AND METHODS

Key publications of recent clinical trials and preclinical studies on the underlying biological mechanisms were analyzed.

RESULTS

As already observed in other tumor entities, synergistic effects upon combination of immunotherapy with radio- and/or chemotherapy are observed in the clinical management of recurrent and/or metastatic HNSCC, and this is mediated by (re)activation of host antitumor immune mechanisms. In selected patients, this may be radiologically detected as pseudoprogression. Reliable biomarkers for these phenomena have not yet been clinically established.

CONCLUSIONS

For recurrent and/or metastatic HNSCC, the occurrence of systemic effects upon radiochemoimmunotherapy in the clinic is on the rise. Hence, the identification of biomarkers for abscopal effects of radiotherapy and unexpected synergisms between chemotherapy and immunotherapy as well as for pseudoprogression is gaining in importance.

Comparison between the Interferon γ Release Assay-QuantiFERON Gold Plus (QFT-Plus)-and Tuberculin Skin Test (TST) in the Detection of Tuberculosis Infection in Immunocompromised Children

Background

Immunocompromised patients are at a higher risk of having latent tuberculosis infection (LTBI). QuantiFERON-TB Gold Plus (QFT-Plus) has been proven to perform effectively in LTBI detection among immunocompromised adults and can overcome the limitations of the tuberculin skin test (TST). However, the role of QFT-Plus in detecting LTBI in immunocompromised paediatric patients has not been well established. Therefore, the aim of this study was to assess the test agreement between QFT-Plus and the TST in LTBI detection among immunocompromised children.

Method

In this cross-sectional study, we enrolled immunocompromised paediatric patients, aged between 5 and 18 years, who were treated with corticosteroids and/or chemotherapy from June to November 2019. We categorized them into three groups based on the following diseases: hematologic malignancies and nephrological and immunological diseases. We recorded the patient characteristics and QFT-Plus and TST results, in which the positive result of the TST was induration ≥ 5 mm. Within the same group, comparisons between the two tests were performed using the McNemar test, and results were statistically significant for p values of <0.05. The kappa index was used to assess the agreement between the two test results.

Results

Among 71 patients (median age: 11.8 years) who underwent TST and QFT-Plus testing, 52% were females, and 69% had a normal nutritional status. Chemotherapy was the most common treatment modality for hematologic malignancy compared to other immunosuppressive treatments. The total number of patients with positive QFT-Plus and TST results was 11/71 (15.5%) and 4/71 (5.6%), respectively, among whom 3/11 patients had positive results in both tests, and one patient with positive TST results exhibited a discrepancy, as this was not followed by positive QFT-Plus results. QFT-Plus generated more positive results than the TST in immunocompromised children (McNemar, p = 0.039 (p < 0.05)). The diagnostic agreement between the tests was fair (K = 0.345, 95% CI: 0.05–0.745).

Conclusion

QFT-Plus detected LTBI more effectively than the TST in immunocompromised children.

Malignant cell-specific pro-tumorigenic role of type I interferon receptor in breast cancers

Within the microenvironment of solid tumors, stress associated with deficit of nutrients and oxygen as well as tumor-derived factors triggers the phosphorylation-dependent degradation of the IFNAR1 chain of type I interferon (IFN1) receptor and ensuing suppression of the IFN1 pathway. Here we sought to examine the importance of these events in malignant mammary cells. Expression of non-degradable IFNAR1^S526A mutant in mouse mammary adenocarcinoma cells stimulated the IFN1 pathway yet did not affect growth of these cells in vitro or ability to form subcutaneous tumors in the syngeneic mice. Remarkably, these cells exhibited a notably accelerated growth when transplanted orthotopically into mammary glands. Importantly, in human patients with either ER+ or ER- breast cancers, high levels of IFNAR1 were associated with poor prognosis. We discuss the putative mechanisms underlying the pro-tumorigenic role of IFNAR1 in malignant breast cells.