Upregulation of C/EBPα Inhibits Suppressive Activity of Myeloid Cells and Potentiates Antitumor Response in Mice and Patients with Cancer

Clinical landscape of macrophage-reprogramming cancer immunotherapies

Tumour-associated macrophages (TAMs) sustain a tumour-supporting and immunosuppressive milieu and therefore aggravate cancer prognosis. To modify TAM behaviour and unlock their anti-tumoural potential, novel TAM-reprogramming immunotherapies are being developed at an accelerating rate. At the same time, scientific discoveries have highlighted more sophisticated TAM phenotypes with complex biological functions and contradictory prognostic associations. To understand the evolving clinical landscape, we reviewed current and past clinically evaluated TAM-reprogramming cancer therapeutics and summarised almost 200 TAM-reprogramming agents investigated in more than 700 clinical trials. Observable overall trends include a high frequency of overlapping strategies against the same therapeutic targets, development of more complex strategies to improve previously ineffective approaches and reliance on combinatory strategies for efficacy. However, strong anti-tumour efficacy is uncommon, which encourages re-directing efforts on identifying biomarkers for eligible patient populations and comparing similar treatments earlier. Future endeavours will benefit from considering the shortcomings of past treatment strategies and accommodating the emerging complexity of TAM biology.

Impact of Pulmonary microbiota on lung cancer treatment-related pneumonia

Background: The use of immunotherapy is progressively expanding for the treatment of lung cancer, either alone or in combination with radiotherapy. However, treatment-related adverse events, especially pneumonia, significantly limit the drug's effectiveness in treating lung cancer. The occurrence of lung cancer, immunotherapy, and pulmonary radiotherapy can all contribute to the imbalance in the pulmonary microbiota, rendering the lungs more susceptible to inflammatory reactions. Methods: Mouse models of lung transplantation tumor were treated with either PD-1 monoclonal antibody or radiotherapy alone, or in combination. The differences in lung inflammation among the different treatment groups were regularly observed by micro-CT. Further, bronchoalveolar lavage fluid was extracted for macrogenomic and cytokine detection. The transcriptional genome of tumor-filled lung tissue was also sequenced. Results: When treated with a combination of PD-1 and radiotherapy, the CT scans showed more severe pulmonary inflammation. However, with the addition of continuously administered antibiotics, no exacerbation of pneumonia signs was observed. Moreover, the differential gene expression and cytokine profiles in the combination treatment group differed from those in the PD-1 monotherapy group and the radiotherapy monotherapy group. This discrepancy does not seem to be a straightforward superimposition of radiation-induced pneumonia and immune-related pneumonia. Further exploration of changes in pulmonary microbiota revealed specific bacterial interactions with DEGs and cytokines. Conclusions: The underlying causes of this susceptibility are intricate and may be associated with the complexity of pulmonary microbiota imbalance, along with fluctuations in the abundance of specific microbiota species.

Understanding the immunosuppressive microenvironment of glioma: mechanistic insights and clinical perspectives

Glioblastoma (GBM), the predominant and primary malignant intracranial tumor, poses a formidable challenge due to its immunosuppressive microenvironment, thereby confounding conventional therapeutic interventions. Despite the established treatment regimen comprising surgical intervention, radiotherapy, temozolomide administration, and the exploration of emerging modalities such as immunotherapy and integration of medicine and engineering technology therapy, the efficacy of these approaches remains constrained, resulting in suboptimal prognostic outcomes. In recent years, intensive scrutiny of the inhibitory and immunosuppressive milieu within GBM has underscored the significance of cellular constituents of the GBM microenvironment and their interactions with malignant cells and neurons. Novel immune and targeted therapy strategies have emerged, offering promising avenues for advancing GBM treatment. One pivotal mechanism orchestrating immunosuppression in GBM involves the aggregation of myeloid-derived suppressor cells (MDSCs), glioma-associated macrophage/microglia (GAM), and regulatory T cells (Tregs). Among these, MDSCs, though constituting a minority (4-8%) of CD45+ cells in GBM, play a central component in fostering immune evasion and propelling tumor progression, angiogenesis, invasion, and metastasis. MDSCs deploy intricate immunosuppressive mechanisms that adapt to the dynamic tumor microenvironment (TME). Understanding the interplay between GBM and MDSCs provides a compelling basis for therapeutic interventions. This review seeks to elucidate the immune regulatory mechanisms inherent in the GBM microenvironment, explore existing therapeutic targets, and consolidate recent insights into MDSC induction and their contribution to GBM immunosuppression. Additionally, the review comprehensively surveys ongoing clinical trials and potential treatment strategies, envisioning a future where targeting MDSCs could reshape the immune landscape of GBM. Through the synergistic integration of immunotherapy with other therapeutic modalities, this approach can establish a multidisciplinary, multi-target paradigm, ultimately improving the prognosis and quality of life in patients with GBM.

Macrophages Orchestrate the Liver Tumor Microenvironment

Liver cancer is one of the leading causes of cancer-related mortality. Hepatocellular carcinoma and cholangiocarcinoma are the most common types, and despite numerous advances, therapeutic options still remain poor for these cancer patients. Tumor development and progression strictly depend on a supportive tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are the most abundant immune cells population within a tumorigenic liver; they sustain cancer cells' growth and invasiveness, and their presence is correlated with a poor prognosis. Furthermore, TAM cross-talk with cells and components of the TME promotes immunosuppression, a desmoplastic response, and angiogenesis. In this review, we summarize the latest advances in understanding TAM heterogeneity and function, with a particular focus on TAM modulation of the TME. We also discuss the potential of targeting macrophage subpopulations and how this is now being exploited in current clinical trials for the treatment of liver cancer.

Engineering and Targeting Neutrophils for Cancer Therapy

Neutrophils are the most abundant white blood cells in the circulation and act as the first line of defense against infections. Increasing evidence suggests that neutrophils possess heterogeneous phenotypes and functional plasticity in human health and diseases, including cancer. Neutrophils play multifaceted roles in cancer development and progression, and an N1/N2 paradigm of neutrophils in cancer is proposed, where N1 neutrophils exert anti-tumor properties while N2 neutrophils display tumor-supportive and immune-suppressive functions. Selective activation of beneficial neutrophil population and targeted inhibition or re-polarization of tumor-promoting neutrophils has shown an important potential in tumor therapy. In addition, due to the natural inflammation-responsive and physical barrier-crossing abilities, neutrophils and their derivatives (membranes and extracellular vesicles (EVs)) are regarded as advanced drug delivery carriers for enhanced tumor targeting and improved therapeutic efficacy. In this review, the recent advances in engineering neutrophils for drug delivery and targeting neutrophils for remodeling tumor microenvironment (TME) are comprehensively presented. This review will provide a broad understanding of the potential of neutrophils in cancer therapy.

Hepatocyte-specific CCAAT/enhancer binding protein α restricts liver fibrosis progression

Metabolic dysfunction-associated steatohepatitis (MASH) - previously described as nonalcoholic steatohepatitis (NASH) - is a major driver of liver fibrosis in humans, while liver fibrosis is a key determinant of all-cause mortality in liver disease independent of MASH occurrence. CCAAT/enhancer binding protein α (CEBPA), as a versatile ligand-independent transcriptional factor, has an important function in myeloid cells, and is under clinical evaluation for cancer therapy. CEBPA is also expressed in hepatocytes and regulates glucolipid homeostasis; however, the role of hepatocyte-specific CEBPA in modulating liver fibrosis progression is largely unknown. Here, hepatic CEBPA expression was found to be decreased during MASH progression both in humans and mice, and hepatic CEBPA mRNA was negatively correlated with MASH fibrosis in the human liver. CebpaΔHep mice had markedly enhanced liver fibrosis induced by a high-fat, high-cholesterol, high-fructose diet or carbon tetrachloride. Temporal and spatial hepatocyte-specific CEBPA loss at the progressive stage of MASH in CebpaΔHep,ERT2 mice functionally promoted liver fibrosis. Mechanistically, hepatocyte CEBPA directly repressed Spp1 transactivation to reduce the secretion of osteopontin, a fibrogenesis inducer of hepatic stellate cells. Forced hepatocyte-specific CEBPA expression reduced MASH-associated liver fibrosis. These results demonstrate an important role for hepatocyte-specific CEBPA in liver fibrosis progression, and may help guide the therapeutic discoveries targeting hepatocyte CEBPA for the treatment of liver fibrosis.

C/EBPα mediates the maturation and antitumor functions of macrophages in human hepatocellular carcinoma

Recent studies have suggested that therapeutic upregulation of CCAAT/enhancer binding protein α (C/EBPα) prevents hepatocellular carcinoma (HCC) progression. However, the mechanisms underlying this outcome are not fully understood. In this study, we investigated the expression and functional roles of C/EBPα in human HCC, with a focus on monocytes/macrophages (Mφs). Paraffin-embedded tissues were used to visualize C/EBPα expression and analyze the prognostic value of C/EBPα+ monocytes/Mφs in HCC patients. The underlying regulatory mechanisms were examined using human monocyte-derived Mφs. The results showed that the expression of C/EBPα on monocytes/Mφs was significantly decreased in intra-tumor tissues compared to the corresponding peri-tumor tissues. C/EBPα+ monocytes/Mφs displayed well-differentiation and antitumor capacities, and the accumulation of these cells in tissue was associated with antitumor immune responses and predicted longer overall survival (OS) of HCC patients. Mechanistic studies demonstrated that C/EBPα was required for Mφ maturation and HLA-DR, CD169 and CD86 expression, which initiates antitumor cytotoxic T-cell responses; however, these effects were inhibited by monocyte autocrine IL-6- and IL-1β-induced suppression of mTOR1 signaling. Reprogramming Mφs via the upregulation of C/EBPα may provide a novel strategy for cancer immunotherapy in patients with HCC.

CEBPA facilitates LOXL2 and LOXL3 transcription to promote BCL-2 stability and thus enhances the growth and metastasis of lung carcinoma cells in vitro

Lung carcinoma (LC) is a complicated and highly heterogeneous disease with high morbidity and mortality. Both lysyl oxidase-like (LOXL) 2 and 3 act in cancer progression. This work endeavors to illustrate the influence of LOXL2/LOXL3 on LC progression and the underlying mechanisms. LOXL family genes and CCAAT enhancer binding protein A (CEBPA) were analyzed in the TCGA database for their expression patterns in LC patients and their correlations with the patient's prognosis. CEBPA, LOXL2, and LOXL3 expression levels were determined in LC cells. Gain- and loss-of-function assays were conducted, followed by assays for cell proliferation, epithelial-mesenchymal transition (EMT), apoptosis, invasion, and migration. The binding of CEBPA or B cell lymphoma protein (BCL)-2 to LOXL2/LOXL3 was verified. The ubiquitination level of BCL-2 and histone acetylation level of LOXL2/LOXL3 in LC cells were analyzed. Database analyses revealed that LC patients had high CEBPA, LOXL2, and LOXL3 expression, which were related to poor prognosis. LC cells also exhibited high CEBPA, LOXL2, and LOXL3 levels. LOXL2/LOXL3 knockdown subdued EMT, proliferation, migration, and invasion while enhancing the apoptosis of LC cells. LOXL2/LOXL3 could bind to CEBPA and BCL-2. LOXL2/LOXL3 knockdown upregulated BCL-2 ubiquitination level and diminished BCL-2 expression in LC cells. CEBPA recruited Tip60 to enhance histone acetylation and transcription of LOXL2/LOXL3 in LC cells. BCL-2 overexpression abolished the impacts of LOXL2/LOXL3 knockdown on LC cells. In conclusion, CEBPA boosts LOXL2 and LOXL3 transcription to facilitate BCL-2 stability by recruiting Tip60 and thus contributes to LC cell growth and metastasis.

Myeloid-derived suppressor cells in cancer and cancer therapy

Anticancer agents continue to dominate the list of newly approved drugs, approximately half of which are immunotherapies. This trend illustrates the considerable promise of cancer treatments that modulate the immune system. However, the immune system is complex and dynamic, and can have both tumour-suppressive and tumour-promoting effects. Understanding the full range of immune modulation in cancer is crucial to identifying more effective treatment strategies. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of myeloid cells that develop in association with chronic inflammation, which is a hallmark of cancer. Indeed, MDSCs accumulate in the tumour microenvironment, where they strongly inhibit anticancer functions of T cells and natural killer cells and exert a variety of other tumour-promoting effects. Emerging evidence indicates that MDSCs also contribute to resistance to cancer treatments, particularly immunotherapies. Conversely, treatment approaches designed to eliminate cancer cells can have important additional effects on MDSC function, which can be either positive or negative. In this Review, we discuss the interplay between MDSCs and various other cell types found in tumours as well as the mechanisms by which MDSCs promote tumour progression. We also discuss the relevance and implications of MDSCs for cancer therapy.

Reciprocal relationship between cancer stem cells and myeloid-derived suppressor cells: implications for tumor progression and therapeutic strategies

Recently, there has been an increased focus on cancer stem cells (CSCs) due to their resilience, making them difficult to eradicate. This resilience often leads to tumor recurrence and metastasis. CSCs adeptly manipulate their surroundings to create an environment conducive to their survival. In this environment, myeloid-derived suppressor cells (MDSCs) play a crucial role in promoting epithelial-mesenchymal transition and bolstering CSCs' stemness. In response, CSCs attract MDSCs, enhancing their infiltration, expansion and immunosuppressive capabilities. This interaction between CSCs and MDSCs increases the difficulty of antitumor therapy. In this paper, we discuss the interplay between CSCs and MDSCs based on current research and highlight recent therapeutic strategies targeting either CSCs or MDSCs that show promise in achieving effective antitumor outcomes.

Emerging roles of MITF as a crucial regulator of immunity

Microphthalmia-associated transcription factor (MITF), a basic helix-loop-helix leucine zipper transcription factor (bHLH-Zip), has been identified as a melanocyte-specific transcription factor and plays a critical role in melanocyte survival, differentiation, function, proliferation and pigmentation. Although numerous studies have explained the roles of MITF in melanocytes and in melanoma development, the function of MITF in the hematopoietic or immune system-beyond its function in melanin-producing cells-is not yet fully understood. However, there is convincing and increasing evidence suggesting that MITF may play multiple important roles in immune-related cells. Therefore, this review is focused on recent advances in elucidating novel functions of MITF in cancer progression and immune responses to cancer. In particular, we highlight the role of MITF as a central modulator in the regulation of immune responses, as elucidated in recent studies.

The Roles of Myeloid-Derived Suppressor Cells in Liver Disease

Liver disease-related mortality is a major cause of death worldwide. Hepatic innate and adaptive immune cells play diverse roles in liver homeostasis and disease. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells. MDSCs can be broadly divided into monocytic MDSCs and polymorphonuclear or granulocytic MDSCs, and they functionally interact with both liver parenchymal and nonparenchymal cells, such as hepatocytes and regulatory T cells, to impact liver disease progression. The infiltration and activation of MDSCs in liver disease can be regulated by inflammatory chemokines and cytokines, tumor-associated fibroblasts, epigenetic regulation factors, and gut microbiota during liver injury and cancer. Given the pivotal roles of MDSCs in advanced liver diseases, they can be targeted to treat primary and metastatic liver cancer, liver generation, alcoholic and nonalcoholic liver disease, and autoimmune hepatitis. Currently, several treatments such as the antioxidant and anti-inflammatory agent berberine are under preclinical and clinical investigation to evaluate their therapeutic efficacy on liver disease and their effect on MDSC infiltration and function. Phenotypic alteration of MDSCs in different liver diseases that are in a model-dependent manner and lack special markers for distinct MDSCs are challenges for targeting MDSCs to treat liver disease. Multi-omics study is an option to uncover the features of disease-specific MDSCs and potential gene or protein targets for liver disease treatment. In summary, MDSCs play important roles in the pathogenesis and progression of liver disease by regulating both intrahepatic innate and adaptive immune responses.

Transcription factors in the development and treatment of immune disorders

Immune function is highly controlled at the transcriptional level by the binding of transcription factors (TFs) to promoter and enhancer elements. Several TF families play major roles in immune gene expression, including NF-κB, STAT, IRF, AP-1, NRs, and NFAT, which trigger anti-pathogen responses, promote cell differentiation, and maintain immune system homeostasis. Aberrant expression, activation, or sequence of isoforms and variants of these TFs can result in autoimmune and inflammatory diseases as well as hematological and solid tumor cancers. For this reason, TFs have become attractive drug targets, even though most were previously deemed "undruggable" due to their lack of small molecule binding pockets and the presence of intrinsically disordered regions. However, several aspects of TF structure and function can be targeted for therapeutic intervention, such as ligand-binding domains, protein-protein interactions between TFs and with cofactors, TF-DNA binding, TF stability, upstream signaling pathways, and TF expression. In this review, we provide an overview of each of the important TF families, how they function in immunity, and some related diseases they are involved in. Additionally, we discuss the ways of targeting TFs with drugs along with recent research developments in these areas and their clinical applications, followed by the advantages and disadvantages of targeting TFs for the treatment of immune disorders.

Transient receptor potential-related risk model predicts prognosis of hepatocellular carcinoma patients

BACKGROUND

Members of the transient receptor potential (TRP) protein family shape oncogenic development, but the specific relevance of TRP-related genes in hepatocellular carcinoma (HCC) has yet to be defined.

AIM

To investigate the role of TRP genes in HCC, their association with HCC development and treatment was examined.

METHODS

HCC patient gene expression and clinical data were downloaded from The Cancer Genome Atlas database, and univariate and least absolute shrinkage and selection operator Cox regression models were employed to explore the TRP-related risk spectrum. Based on these analyses, clinically relevant TRP family genes were selected, and the association between the key TRP canonical type 1 (TRPC1) gene and HCC patient prognosis was evaluated.

RESULTS

In total, 28 TRP family genes were screened for clinical relevance, with multivariate analyses ultimately revealing three of these genes (TRPC1, TRP cation channel subfamily M member 2, and TRP cation channel subfamily M member 6) to be significantly associated with HCC patient prognosis (P < 0.05). These genes were utilized to establish a TRP-related risk model. Patients were separated into low- and high-risk groups based on the expression of these genes, and high-risk patients exhibited a significantly poorer prognosis (P = 0.001). Functional analyses highlighted pronounced differences in the immune status of patients in these two groups and associated enriched immune pathways. TRPC1 was identified as a candidate gene in this family worthy of further study, with HCC patients expressing higher TRPC1 levels exhibiting poorer survival outcomes. Consistently, quantitative, immunohistochemistry, and western blot analyses revealed increased TRPC1 expression in HCC.

CONCLUSION

These three TRP genes help determine HCC patient prognosis, providing insight into tumor immune status and immunological composition. These findings will help design combination therapies including immunotherapeutic and anti-TRP agents.

The role of tumor-associated macrophages in hepatocellular carcinoma progression: A narrative review

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world, with complex etiology and mechanism, and a high mortality rate. Tumor-associated macrophages (TAMs) are an important part of the HCC tumor microenvironment. Studies in recent years have shown that TAMs are involved in multiple stages of HCC and are related to treatment and prognosis in HCC. The specific mechanisms between TAMs and HCC are gradually being revealed. This paper reviews recent advances in the mechanisms associated with TAMs in HCC, concentrating on an overview of effects of TAMs on drug resistance in HCC and the signaling pathways linked with HCC, providing clues for the treatment and prognosis determination of HCC.

Targeting the Heterogeneous Tumour-Associated Macrophages in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a prevalent and aggressive cancer that comprises a complex tumour microenvironment (TME). Tumour-associated macrophages (TAMs) are one of the most abundant immune cells present in the TME, and play a key role both in the development and in the progression of HCC. Thus, TAM-based immunotherapy has been presented as a promising strategy to complement the currently available therapies for HCC treatment. Among the novel approaches focusing on TAMs, reprogramming their functional state has emerged as a promising option for targeting TAMs as an immunotherapy in combination with the currently available treatment options. Nevertheless, a further understanding of the immunobiology of TAMs is still required. This review synthesizes current insights into the heterogeneous nature of TAMs in HCC and describes the mechanisms behind their pro-tumoural polarization focusing the attention on their interaction with HCC cells. Furthermore, this review underscores the potential involvement of TAMs' reprogramming in HCC therapy and highlights the urgency of advancing our understanding of these cells within the dynamic landscape of HCC.

Cancer Stem Cells and the Tumor Microenvironment in Tumor Drug Resistance

Although there has been some progress in the efficacy of anti-cancer drugs, drug resistance remains challenging. Cancer stem cells (CSCs) are self-renewing and differentiate into cancer tissues with tumor heterogeneity. CSCs are associated with the progression of breast, colon, and lung cancers. Hence, recent studies have focused on the role of CSCs in resistance to anti-cancer drugs. Increasing evidence suggests that CSCs interact with components of the tumor microenvironment (TME), such as vascular and immune cells, as well as various cytokines, and are regulated by multiple signaling pathways, thereby promoting drug resistance in various cancers. Therefore, it is important to clarify the mechanisms underlying the crosstalk between CSCs and the TME for the development of targeted anti-cancer therapies.

Comparative analyses of monocyte memory dynamics from mice to humans

BACKGROUND

Innate monocytes can adopt dynamic "memory" states ranging from low-grade inflammation to pathogenic exhaustion, dependent upon signal strength and history of challenges. Low-grade inflammatory monocytes facilitate the pathogenesis of chronic inflammatory diseases, while exhausted monocytes drive the pathogenesis of severe sepsis. Although clinical and basic studies suggest the conservation of key features of exhausted monocytes from human and murine sepsis, systems analyses of monocyte exhaustion among human and murine monocytes are lacking.

METHODS

We performed cross examination of septic monocytes scRNAseq data recently collected from human sepsis patients as well as experimental septic mice, in reference to monocytes experimentally exhausted in vitro. Furthermore, we performed pseudo-time analyses of in vitro programmed monocytes following prolonged challenges causing either low-grade inflammation or exhaustion. Additional comparative analyses of low-grade inflammatory monocytes were performed with scRNAseq data from selected human patients with chronic low-grade inflammatory diseases.

RESULTS

Our systems analyses reveal key features of monocyte exhaustion including reduced differentiation, pathogenic inflammation and immune suppression that are highly conserved in human and murine septic monocytes, and captured by in vitro experimental exhaustion. Pseudo-time analyses reveal that monocytes initially transition into a less-differentiated state with proliferative potential. The expansion of proliferative monocytes can be observed not only in experimentally challenged monocytes, but also in tissues of murine sepsis and human septic blood. We observed that monocytes similarly transition into the less-differentiated state when challenged with a subclinical dose endotoxin under chronic inflammatory conditions. Instead of being exhausted, monocytes with prolonged challenges with super-low dose endotoxin bifurcate into the low-grade inflammatory immune-enhancing or the chemotactic/adhesive state, often see in atherosclerosis or auto-immune diseases.

CONCLUSIONS

Key features of monocyte memory dynamics are identified and conserved in human and murine monocytes, which can be captured by prolonged challenges of innate signals with varying signal strength.

The new world of RNA diagnostics and therapeutics

The 5th Workshop IRE on Translational Oncology was held in Rome (Italy) on 27-28 March at the IRCCS Regina Elena National Cancer Institute. This meeting entitled "The New World of RNA diagnostics and therapeutics" highlightes the significant progress in the RNA field made over the last years. Research moved from pure discovery towards the development of diagnostic biomarkers or RNA-base targeted therapies seeking validation in several clinical trials. Non-coding RNAs in particular have been the focus of this workshop due to their unique properties that make them attractive tools for the diagnosis and therapy of cancer.This report collected the presentations of many scientists from different institutions that discussed recent oncology research providing an excellent overview and representative examples for each possible application of RNA as biomarker, for therapy or to increase the number of patients that can benefit from precision oncology treatment.In particular, the meeting specifically emphasized two key features of RNA applications: RNA diagnostic (Blandino, Palcau, Sestito, Díaz Méndez, Cappelletto, Pulito, Monteonofrio, Calin, Sozzi, Cheong) and RNA therapeutics (Dinami, Marcia, Anastasiadou, Ryan, Fattore, Regazzo, Loria, Aharonov).

Long non-coding RNA-targeting therapeutics: discovery and development update

INTRODUCTION

lncRNAs are major players in regulatory networks orchestrating multiple cellular functions, such as 3D chromosomal interactions, epigenetic modifications, gene expression and others. Due to progress in the development of nucleic acid-based therapeutics, lncRNAs potentially represent easily accessible therapeutic targets.

AREAS COVERED

Currently, significant efforts are directed at studies that can tap the enormous therapeutic potential of lncRNAs. This review describes recent developments in this field, particularly focusing on clinical applications.

EXPERT OPINION

Extensive druggable target range of lncRNA combined with high specificity and accelerated development process of nucleic acid-based therapeutics open new prospects for treatment in areas of extreme unmet medical need, such as genetic diseases, aggressive cancers, protein deficiencies, and subsets of common diseases caused by known mutations. Although currently wide acceptance of lncRNA-targeting nucleic acid-based therapeutics is impeded by the need for parenteral or direct-to-CNS administration, development of less invasive techniques and orally available/BBB-penetrant nucleic acid-based therapeutics is showing early successes. Recently, mRNA-based COVID-19 vaccines have demonstrated clinical safety of all aspects of nucleic acid-based therapeutic technology, including multiple chemical modifications of nucleic acids and nanoparticle delivery. These trends position lncRNA-targeting drugs as significant players in the future of drug development, especially in the area of personalized medicine.

Amplifying gene expression with RNA-targeted therapeutics

Many diseases are caused by insufficient expression of mutated genes and would benefit from increased expression of the corresponding protein. However, in drug development, it has been historically easier to develop drugs with inhibitory or antagonistic effects. Protein replacement and gene therapy can achieve the goal of increased protein expression but have limitations. Recent discoveries of the extensive regulatory networks formed by non-coding RNAs offer alternative targets and strategies to amplify the production of a specific protein. In addition to RNA-targeting small molecules, new nucleic acid-based therapeutic modalities that allow highly specific modulation of RNA-based regulatory networks are being developed. Such approaches can directly target the stability of mRNAs or modulate non-coding RNA-mediated regulation of transcription and translation. This Review highlights emerging RNA-targeted therapeutics for gene activation, focusing on opportunities and challenges for translation to the clinic.

Investigating the effects of long-term Aroclor 1260 exposure on fatty liver disease in a diet-induced obesity mouse model

Introduction

Polychlorinated biphenyls (PCBs) are persistent environmental toxicants that have been implicated in numerous health disorders including liver diseases such as non-alcoholic fatty liver disease (NAFLD). Toxicant-associated NAFLD, also known as toxicant-associated fatty liver disease (TAFLD), consists of a spectrum of disorders ranging from steatosis and steatohepatitis to fibrosis and hepatocellular carcinoma. Previously, our group demonstrated that 12-week exposure to the PCB mixture, Aroclor 1260, exacerbated steatohepatitis in high-fat diet (HFD)-fed mice; however, the longer-term effects of PCBs on TAFLD remain to be elucidated. This study aims to examine the longer-term effects of Aroclor 1260 (>30 weeks) in a diet-induced obesity model to better understand how duration of exposure can impact TAFLD.

Methods

Male C57BL/6 mice were exposed to Aroclor 1260 (20 mg/kg) or vehicle control by oral gavage at the beginning of the study period and fed either a low-fat diet (LFD) or HFD throughout the study period.

Results

Aroclor 1260 exposure (>30 weeks) led to steatohepatitis only in LFD-fed mice. Several Aroclor 1260 exposed LFD-fed mice also developed hepatocellular carcinoma (25%), which was absent in HFD-fed mice. The LFD+Aroclor1260 group also exhibited decreased hepatic Cyp7a1 expression and increased pro-fibrotic Acta2 expression. In contrast, longer term Aroclor 1260 exposure in conjunction with HFD did not exacerbate steatosis or inflammatory responses beyond those observed with HFD alone. Further, hepatic xenobiotic receptor activation by Aroclor 1260 was absent at 31 weeks post exposure, suggesting PCB redistribution to the adipose and other extra-hepatic tissues with time.

Discussion

Overall, the results demonstrated that longer-term PCB exposure worsened TAFLD outcomes independent of HFD feeding and suggests altered energy metabolism as a potential mechanism fueling PCB mediated toxicity without dietary insult. Additional research exploring mechanisms for these longer-term PCB mediated toxicity in TAFLD is warranted.

Interdisciplinary advances reshape the delivery tools for effective NASH treatment

BACKGROUND

Nonalcoholic steatohepatitis (NASH), a severe systemic and inflammatory subtype of nonalcoholic fatty liver disease, eventually develops into cirrhosis and hepatocellular carcinoma with few options for effective treatment. Currently potent small molecules identified in preclinical studies are confronted with adverse effects and long-term ineffectiveness in clinical trials. Nevertheless, highly specific delivery tools designed from interdisciplinary concepts may address the significant challenges by either effectively increasing the concentrations of drugs in target cell types, or selectively manipulating the gene expression in liver to resolve NASH.

SCOPE OF REVIEW

We focus on dissecting the detailed principles of the latest interdisciplinary advances and concepts that direct the design of future delivery tools to enhance the efficacy. Recent advances have indicated that cell and organelle-specific vehicles, non-coding RNA research (e.g. saRNA, hybrid miRNA) improve the specificity, while small extracellular vesicles and coacervates increase the cellular uptake of therapeutics. Moreover, strategies based on interdisciplinary advances drastically elevate drug loading capacity and delivery efficiency and ameliorate NASH and other liver diseases.

MAJOR CONCLUSIONS

The latest concepts and advances in chemistry, biochemistry and machine learning technology provide the framework and strategies for the design of more effective tools to treat NASH, other pivotal liver diseases and metabolic disorders.

Therapeutic targeting of tumour myeloid cells

Myeloid cells are pivotal within the immunosuppressive tumour microenvironment. The accumulation of tumour-modified myeloid cells derived from monocytes or neutrophils - termed 'myeloid-derived suppressor cells' - and tumour-associated macrophages is associated with poor outcome and resistance to treatments such as chemotherapy and immune checkpoint inhibitors. Unfortunately, there has been little success in large-scale clinical trials of myeloid cell modulators, and only a few distinct strategies have been used to target suppressive myeloid cells clinically so far. Preclinical and translational studies have now elucidated specific functions for different myeloid cell subpopulations within the tumour microenvironment, revealing context-specific roles of different myeloid cell populations in disease progression and influencing response to therapy. To improve the success of myeloid cell-targeted therapies, it will be important to target tumour types and patient subsets in which myeloid cells represent the dominant driver of therapy resistance, as well as to determine the most efficacious treatment regimens and combination partners. This Review discusses what we can learn from work with the first generation of myeloid modulators and highlights recent developments in modelling context-specific roles for different myeloid cell subtypes, which can ultimately inform how to drive more successful clinical trials.

Nanotechnology-enabled gene delivery for cancer and other genetic diseases

INTRODUCTION

Despite gene therapy is ideal for genetic abnormality-related diseases, the easy degradation, poor targeting, and inefficiency in entering targeted cells are plaguing the effective delivery of gene therapy. Viral and non-viral vectors have been used for delivering gene therapeutics in vivo by safeguarding nucleic acid agents to target cells and to reach the specific intracellular location. A variety of nanotechnology-enabled safe and efficient systems have been successfully developed to improve the targeting ability for effective therapeutic delivery of genetic drugs.

AREAS COVERED

In this review, we outline the multiple biological barriers associated with gene delivery process, and highlight recent advances to gene therapy strategy in vivo, including gene correction, gene silencing, gene activation and genome editing. We point out current developments and challenges exist of non-viral and viral vector systems in association with chemical and physical gene delivery technologies and their potential for the future.

EXPERT OPINION

This review focuses on the opportunities and challenges to various gene therapy strategy, with specific emphasis on overcoming the challenges through the development of biocompatibility and smart gene vectors for potential clinical application.

Myeloid cells in the era of cancer immunotherapy: Top 3 unanswered questions

Myeloid cells are increasingly being recognized as central players orchestrating or suppressing antitumor immune responses. With the advent of high-resolution analytical methods such as single-cell technologies, we now appreciate the heterogeneity and complexity of the myeloid compartment in the context of cancer. Because of their highly plastic nature, targeting myeloid cells has shown promising results either as a monotherapy or in combination with immunotherapy in preclinical models and cancer patients. However, the complexity of myeloid cell cellular crosstalk and molecular networks contributes to our poor understanding of the different myeloid cell subsets in tumorigenesis, which makes targeting myeloid cells challenging. Here, we summarize varied myeloid cell subsets and their contribution to tumor progression with a main focus on mononuclear phagocytes. The top three unanswered questions challenging the field of myeloid cells and cancer in the era of cancer immunotherapy are addressed. Through these questions, we discuss how myeloid cell origin and identity influence their function and disease outcomes. Different therapeutic strategies used to target myeloid cells in cancer are also addressed. Finally, the durability of myeloid cell targeting is interrogated by examining the complexity of resultant compensatory cellular and molecular mechanisms.

RNAi in cell nuclei: potential for a new layer of biological regulation and a new strategy for therapeutic discovery

RNA interference is almost always associated with post-transcriptional silencing in the cytoplasm. MicroRNAs (miRNAs) and critical RNAi protein factors like argonaute (AGO) and trinucleotide repeat binding containing 6 protein (TNRC6), however, are also found in cell nuclei, suggesting that nuclear miRNAs may be targets for gene regulation. Designed small duplex RNAs (dsRNAs) can modulate nuclear processes such as transcription and splicing, suggesting that they can also provide leads for therapeutic discovery. The goal of this Perspective is to provide the background on nuclear RNAi necessary to guide discussions on whether nuclear RNAi can play a role in therapeutic development programs.

Advances in the study of myeloid-derived suppressor cells in infectious lung diseases

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature cells capable of inhibiting T-cell responses. MDSCs have a crucial role in the regulation of the immune response of the body to pathogens, especially in inflammatory response and pathogenesis during anti-infection. Pathogens such as bacteria and viruses use MDSCs as their infectious targets, and even some pathogens may exploit the inhibitory activity of MDSCs to enhance pathogen persistence and chronic infection of the host. Recent researches have revealed the pathogenic significance of MDSCs in pathogens such as bacteria and viruses, despite the fact that the majority of studies on MDSCs have focused on tumor immune evasion. With the increased prevalence of viral respiratory infections, the resurgence of classical tuberculosis, and the advent of medication resistance in common bacterial pneumonia, research on MDSCs in these illnesses is intensifying. The purpose of this work is to provide new avenues for treatment approaches to pulmonary infectious disorders by outlining the mechanism of action of MDSCs as a biomarker and therapeutic target in pulmonary infectious diseases.

Aging aggravates acetaminophen-induced acute liver injury and inflammation through inordinate C/EBPα-BMP9 crosstalk

BACKGROUND

Previous studies have shown that bone morphogenetic protein 9 (BMP9) is almost exclusively produced in the liver and reaches tissues throughout the body as a secreted protein. However, the mechanism of BMP9 action and its role in aging-associated liver injury and inflammation are still unclear.

RESULTS

Aging significantly aggravates acetaminophen (APAP)-induced acute liver injury (ALI). Increased expression of CCAAT/enhancer binding protein α (C/EBPα) and BMP9 was identified in aged livers and in hepatocytes and macrophages (MФs) isolated from aged mice. Further analysis revealed that excess BMP9 was directly related to APAP-induced hepatocyte injury and death, as evidenced by activated drosophila mothers against decapentaplegic protein 1/5/9 (SMAD1/5/9) signaling, an increased dead cell/total cell ratio, decreased levels of ATG3 and ATG7, blocked autophagy, increased senescence-associated beta-galactosidase (SA-β-Gal) activity, and a higher rate of senescence-associated secretory phenotype (SASP) acquisition. In contrast, Bmp9 knockout (Bmp9^-/-) partially alleviated the aforementioned manifestations of BMP9 overexpression. Moreover, BMP9 expression was found to be regulated by C/EBPα in vitro and in vivo. Notably, BMP9 also downregulated autophagy through its effect on autophagy-related genes (ATG3 and ATG7) in MΦs, which was associated with aggravated liver injury and SASP acquisition.

CONCLUSIONS

In summary, the present study highlights the crucial roles played by C/EBPα-BMP9 crosstalk and provides insights into the interrelationship between hepatocytes and MΦs during acute liver injury.

Myeloid leukemia factor 1: A "double-edged sword" in health and disease

The occurrence and development of malignancies are closely related to abnormal cell cycle regulation. Myeloid leukemia factor 1 (MLF1) is a small nucleocytoplasmic shuttling protein associated with cell cycle exit, apoptosis, and certain immune functions. Therefore, it is pertinent to explore the role of MLF1 in health and diseases. Studies to date have suggested that MLF1 could act as a double-edged sword, regulating biochemical activities directly or indirectly. In hematopoietic cells, it serves as a protective factor for the development of lineages, and in malignancies, it serves as an oncogenesis factor. The diversity of its functions depends on the binding partners, including tumor inhibitors, scaffolding molecules, mitochondrial membrane proteins, and transcription factors. Emerging evidence indicates that MLF1 influences immune responses as well. This paper reviews the structure, biological function, and research progress on MLF1 in health and diseases to provide new insights for future research.

Histone lysine methyltransferase-related neurodevelopmental disorders: current knowledge and saRNA future therapies

Neurodevelopmental disorders encompass a group of debilitating diseases presenting with motor and cognitive dysfunction, with variable age of onset and disease severity. Advances in genetic diagnostic tools have facilitated the identification of several monogenic chromatin remodeling diseases that cause Neurodevelopmental disorders. Chromatin remodelers play a key role in the neuro-epigenetic landscape and regulation of brain development; it is therefore not surprising that mutations, leading to loss of protein function, result in aberrant neurodevelopment. Heterozygous, usually de novo mutations in histone lysine methyltransferases have been described in patients leading to haploinsufficiency, dysregulated protein levels and impaired protein function. Studies in animal models and patient-derived cell lines, have highlighted the role of histone lysine methyltransferases in the regulation of cell self-renewal, cell fate specification and apoptosis. To date, in depth studies of histone lysine methyltransferases in oncology have provided strong evidence of histone lysine methyltransferase dysregulation as a determinant of cancer progression and drug resistance. As a result, histone lysine methyltransferases have become an important therapeutic target for the treatment of different cancer forms. Despite recent advances, we still lack knowledge about the role of histone lysine methyltransferases in neuronal development. This has hampered both the study and development of precision therapies for histone lysine methyltransferases-related Neurodevelopmental disorders. In this review, we will discuss the current knowledge of the role of histone lysine methyltransferases in neuronal development and disease progression. We will also discuss how RNA-based technologies using small-activating RNAs could potentially provide a novel therapeutic approach for the future treatment of histone lysine methyltransferase haploinsufficiency in these Neurodevelopmental disorders, and how they could be first tested in state-of-the-art patient-derived neuronal models.

Modulating the expression of tumor suppressor genes using activating oligonucleotide technologies as a therapeutic approach in cancer

Tumor suppressor genes (TSGs) are frequently downregulated in cancer, leading to dysregulation of the pathways that they control. The continuum model of tumor suppression suggests that even subtle changes in TSG expression, for example, driven by epigenetic modifications or copy number alterations, can lead to a loss of gene function and a phenotypic effect. This approach to exploring tumor suppression provides opportunities for alternative therapies that may be able to restore TSG expression toward normal levels, such as oligonucleotide therapies. Oligonucleotide therapies involve the administration of exogenous nucleic acids to modulate the expression of specific endogenous genes. This review focuses on two types of activating oligonucleotide therapies, small-activating RNAs and synthetic mRNAs, as novel methods to increase the expression of TSGs in cancer.

Enhancing SIRT1 Gene Expression Using Small Activating RNAs: A Novel Approach for Reversing Metabolic Syndrome

Metabolic syndrome (MetS) is a pathological condition characterized by abdominal obesity, insulin resistance, hypertension, and hyperlipidemia. Sirtuin 1 (SIRT1), a highly conserved histone deacetylase, is characterized as a key metabolic regulator and protector against aging-associated pathologies, including MetS. In this study, we investigate the therapeutic potential of activating SIRT1 using small activating RNAs (saRNA), thereby reducing inflammatory-like responses and re-establishing normal lipid metabolism. SIRT1 saRNA significantly increased SIRT1 messenger RNA (mRNA) and protein levels in both lipopolysaccharide-stimulated and nonstimulated macrophages. SIRT1 saRNA significantly decreased inflammatory-like responses, by reducing mRNA levels of key inflammatory cytokines, such as Tumor Necrosis Factor alpha, Interleukin 1 beta (IL-1β), Interleukin 6 (IL-6), and chemokines Monocyte Chemoattractant Protein-1 and keratinocyte chemoattractant. SIRT1 overexpression also significantly reduced phosphorylation of nuclear factor-κB and c-Jun N-terminal kinase, both key signaling molecules for the inflammatory pathway. To investigate the therapeutic effect of SIRT1 upregulation, we treated a high-fat diet model with SIRT1 saRNA conjugated to a transferrin receptor aptamer for delivery to the liver and cellular internalization. Animals in the SIRT1 saRNA treatment arm demonstrated significantly decreased weight gain with a significant reduction in white adipose tissue, triglycerides, fasting glucose levels, and intracellular lipid accumulation. These suggest treatment-induced changes to lipid and glucose metabolism in the animals. The results of this study demonstrate that targeted activation of SIRT1 by saRNAs is a potential strategy to reverse MetS.

CIMT 2022: Report on the 19th Annual Meeting of the Association for Cancer Immunotherapy

The 19th Annual Meeting of the Association for Cancer Immunotherapy (CIMT), Europe's cancer immunotherapy meeting, was the first in-person event organized by CIMT since the beginning of the COVID-19 pandemic. As a hybrid event from May 10-12, the meeting attracted 920 academic and clinical professionals from over 40 countries, who met to discuss the latest advances in cancer immunology and immunotherapy research. This report summarizes the highlights of CIMT2022.

Effect and Mechanism Analysis of Pig FUT8 Gene on Resistance to Escherichia coli F18 Infection

Post-weaning diarrhea caused by enterotoxigenic Escherichia coli F18 (E. coli F18) causes significant economic losses for pig producers. Fucosyltransferase 8 (FUT8) is a glycosyltransferase that catalyzes core fucosylation; however, its role in mediating the resistance to E. coli F18 infection in pigs remains unknown. In this study, we systematically verified the relationship between FUT8 expression and E. coli resistance. The results showed that FUT8 was expressed in all detected tissues of Meishan piglets and that its expression was significantly increased in the duodenum and jejunum of E. coli F18-sensitive individuals when compared to E. coli F18-resistant individuals. FUT8 expression increased after exposure to E. coli F18 (p < 0.05) and decreased significantly after LPS induction for 6 h (p < 0.01). Then, the IPEC-J2 stable cell line with FUT8 interference was constructed, and FUT8 knockdown decreased the adhesion of E. coli F18ac to IPEC-J2 cells (p < 0.05). Moreover, we performed a comparative transcriptome study of IPEC-J2 cells after FUT8 knockdown via RNA-seq. In addition, further expression verification demonstrated the significant effect of FUT8 on the glycosphingolipid biosynthesis and Toll-like signaling pathways. Moreover, the core promoter of FUT8, which was located at −1213 bp to −673 bp, was identified via luciferase assay. Interestingly, we found a 1 bp C base insertion mutation at the −774 bp region, which could clearly inhibit the transcriptional binding activity of C/EBPα to an FUT8 promoter. Therefore, it is speculated that FUT8 acts in a critical role in the process of E. coli infection; furthermore, the low expression of FUT8 is conducive to the enhancement of E. coli resistance in piglets. Our findings revealed the mechanism of pig FUT8 in regulating E. coli resistance, which provided a theoretical basis for the screening of E. coli resistance in Chinese local pig breeds.

Strategies for Bottlenecks of rAAV-Mediated Expression in Skeletal and Cardiac Muscle of Duchenne Muscular Dystrophy

Gene therapy using the adeno-associated virus (rAAV) to deliver mini/micro- dystrophin is the current promising strategy for Duchenne Muscular Dystrophy (DMD). However, the further transformation of this strategy still faces many “bottlenecks”. Most gene therapies are only suitable for infants with strong muscle cell regeneration and immature immune system, and the treatment depends heavily on the high dose of rAAV. However, high-dose rAAV inevitably causes side effects such as immune response and acute liver toxicity. Therefore, how to reduce the degree of fibrosis and excessive immune response in older patients and uncouple the dependence association between therapeutic effect and high dose rAAV are crucial steps for the transformation of rAAV-based gene therapy. The article analyzes the latest research and finds that the application of utrophin, the homologous protein of dystrophin, could avoid the immune response associated with dystrophin, and the exploration of methods to improve the expression level of mini/micro-utrophin in striated muscle, combined with the novel MyoAAV with high efficiency and specific infection of striated muscle, is expected to achieve the same therapeutic efficacy under the condition of reducing the dose of rAAV. Furthermore, the delivery of allogeneic cardio sphere-derived cells (CDCs) with anti-inflammatory and anti-fibrotic characteristics combined with immune suppression can provide a continuous and appropriate “window period” for gene therapy. This strategy can expand the number of patients who could benefit from gene therapy.

Tumor Microenvironment in Hepatocellular Carcinoma: Key Players for Immunotherapy

Hepatocellular carcinoma (HCC) remains a serious medical therapeutic challenge as conventional curative avenues such as surgery and chemotherapy only benefit for few patients with limited tumor burden. Immunotherapy achieves clinical progress in the treatment of this prevalent malignant disease by virtue of the development of tumor immunology; however, most patients have experienced minimal or no clinical benefit in terms of overall survival. The complexity and diversity of tumor microenvironment (TME) built by immune and stromal cell subsets has been considered to be responsible for the insufficiency of immunotherapy. The advance of bioanalytical technology boosts the exploration of the composition and differentiation of these infiltrated cells, which reflect the immune state of the TME and impact the efficacy of the antitumor immune response. Targeting these cells to remodel the TME is one of the important immunotherapeutic approaches to improve HCC treatment. In this review, we focused on the role of these non-cancerous cells in the tumor progression, and elaborated their function on cancer immunotherapy when manipulating them as potential targets.

Natural antisense transcripts as drug targets

The recent discovery of vast non-coding RNA-based regulatory networks that can be easily modulated by nucleic acid-based drugs has opened numerous new therapeutic possibilities. Long non-coding RNA, and natural antisense transcripts (NATs) in particular, play a significant role in networks that involve a wide variety of disease-relevant biological mechanisms such as transcription, splicing, translation, mRNA degradation and others. Currently, significant efforts are dedicated to harnessing these newly emerging NAT-mediated biological mechanisms for therapeutic purposes. This review will highlight the recent clinical and pre-clinical developments in this field and survey the advances in nucleic acid-based drug technologies that make these developments possible.

The complement system as a regulator of tumor-promoting activities mediated by myeloid-derived suppressor cells

Tumor progression relies on the interaction between tumor cells and their surrounding tumor microenvironment (TME), which also influences therapeutic responses. The complement system, an essential part of innate immunity, has been traditionally considered an effector arm against tumors. However, established tumors co-opt complement-mediated immune responses in the TME to support chronic inflammation, activate cancer-related signaling pathways and hamper antitumor immune responses. In this context, myeloid-derived suppressor cells (MDSCs), a heterogeneous population of myeloid progenitors with immunosuppressive functions, are recognized as major mediators of tumor-associated complement activities. This review focuses on the impact of complement activation within the TME, with a special emphasis on MDSC functions and the involvement of the C5a/C5aR1 axis. We also discuss the translation of these findings into therapeutic advances based on complement inhibition.

Tumor-associated macrophages in liver cancer: From mechanisms to therapy

Multidimensional analyses have demonstrated the presence of a unique tumor microenvironment (TME) in liver cancer. Tumor-associated macrophages (TAMs) are among the most abundant immune cells infiltrating the TME and are present at all stages of liver cancer progression, and targeting TAMs has become one of the most favored immunotherapy strategies. In addition, macrophages and liver cancer cells have distinct origins. At the early stage of liver cancer, macrophages can provide a niche for the maintenance of liver cancer stem cells. In contrast, cancer stem cells (CSCs) or poorly differentiated tumor cells are key factors modulating macrophage activation. In the present review, we first propose the origin connection between precursor macrophages and liver cancer cells. Macrophages undergo dynamic phenotypic transition during carcinogenesis. In this course of such transition, it is critical to determine the appropriate timing for therapy and block specific markers to suppress pro-tumoral TAMs. The present review provides a more detailed discussion of transition trends of such surface markers than previous reviews. Complex crosstalk occurs between TAMs and liver cancer cells. TAMs play indispensable roles in tumor progression, angiogenesis, and autophagy due to their heterogeneity and robust plasticity. In addition, macrophages in the TME interact with other immune cells by directing cell-to-cell contact or secreting various effector molecules. Similarly, tumor cells combined with other immune cells can drive macrophage recruitment and polarization. Despite the latest achievements and the advancements in treatment strategies following TAMs studies, comprehensive discussions on the communication between macrophages and cancer cells or immune cells in liver cancer are currently lacking. In this review, we discussed the interactions between TAMs and liver cancer cells (from cell origin to maturation), the latest therapeutic strategies (including chimeric antigen receptor macrophages), and critical clinical trials for hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA) to provide a rationale for further clinical investigation of TAMs as a potential target for treating patients with liver cancer.

Tumor immune contexture is a determinant of anti-CD19 CAR T cell efficacy in large B cell lymphoma

Axicabtagene ciloleucel (axi-cel) is an anti-CD19 chimeric antigen receptor (CAR) T cell therapy approved for relapsed/refractory large B cell lymphoma (LBCL) and has treatment with similar efficacy across conventional LBCL subtypes. Toward patient stratification, we assessed whether tumor immune contexture influenced clinical outcomes after axi-cel. We evaluated the tumor microenvironment (TME) of 135 pre-treatment and post-treatment tumor biopsies taken from 51 patients in the ZUMA-1 phase 2 trial. We uncovered dynamic patterns that occurred within 2 weeks after axi-cel. The biological associations among Immunoscore (quantification of tumor-infiltrating T cell density), Immunosign 21 (expression of pre-defined immune gene panel) and cell subsets were validated in three independent LBCL datasets. In the ZUMA-1 trial samples, clinical response and overall survival were associated with pre-treatment immune contexture as characterized by Immunoscore and Immunosign 21. Circulating CAR T cell levels were associated with post-treatment TME T cell exhaustion. TME enriched for chemokines (CCL5 and CCL22), γ-chain receptor cytokines (IL-15, IL-7 and IL-21) and interferon-regulated molecules were associated with T cell infiltration and markers of activity. Finally, high density of regulatory T cells in pre-treatment TME associated with reduced axi-cel–related neurologic toxicity. These findings advance the understanding of LBCL TME characteristics associated with clinical responses to anti-CD19 CAR T cell therapy and could foster biomarker development and treatment optimization for patients with LBCL.

Analysis of tumor biopsies from the pivotal phase 1/2 ZUMA-1 trial identifies pre-treatment T cell–related characteristics that are associated with clinical response and neurologic toxicity after anti-CD19 CAR T cell therapy in patients with large B cell lymphoma.

Targeted Nanocarrier Delivery of RNA Therapeutics to Control HIV Infection

Our understanding of HIV infection has greatly advanced since the discovery of the virus in 1983. Treatment options have improved the quality of life of people living with HIV/AIDS, turning it from a fatal disease into a chronic, manageable infection. Despite all this progress, a cure remains elusive. A major barrier to attaining an HIV cure is the presence of the latent viral reservoir, which is established early in infection and persists for the lifetime of the host, even during prolonged anti-viral therapy. Different cure strategies are currently being explored to eliminate or suppress this reservoir. Several studies have shown that a functional cure may be achieved by preventing infection and also inhibiting reactivation of the virus from the latent reservoir. Here, we briefly describe the main HIV cure strategies, focussing on the use of RNA therapeutics, including small interfering RNA (siRNA) to maintain HIV permanently in a state of super latency, and CRISPR gRNA to excise the latent reservoir. A challenge with progressing RNA therapeutics to the clinic is achieving effective delivery into the host cell. This review covers recent nanotechnological strategies for siRNA delivery using liposomes, N-acetylgalactosamine conjugation, inorganic nanoparticles and polymer-based nanocapsules. We further discuss the opportunities and challenges of those strategies for HIV treatment.

Myeloid-derived suppressor cells promote tumor growth and sorafenib resistance by inducing FGF1 upregulation and fibrosis

Background

Methods

Results

Conclusions

Identification of a Novel Immune-Related lncRNA CTD-2288O8.1 Regulating Cisplatin Resistance in Ovarian Cancer Based on Integrated Analysis

Ovarian cancer (OC) is the most lethal gynecological malignancy, in which chemoresistance is a crucial factor leading to the poor prognosis. Recently, immunotherapy has brought new light for the treatment of solid tumors. Hence, as a kind of immunologically active cancer, it is reasonably necessary to explore the potential mechanism between immune characteristics and cisplatin resistance in OC. Our study focused on the important role of cisplatin resistance-related lncRNAs on mediating the OC tumor immune microenvironment (TIME) using an integrative analysis based on the Cancer Genome Atlas (TCGA) database. First, the cisplatin resistance-related differentially expressed lncRNAs (DELs) and mRNAs (DEMs) were preliminarily screened to construct a DEL–DEM co-expression network. Next, the protein–protein interaction (PPI) network and pivot analysis were performed to reveal the relevance of these lncRNAs with tumor immune response. Second, the novel lncRNA CTD-2288O8.1 was identified as a key gene for the OC cisplatin resistance formation by qRT-PCR and survival analysis. Gain- and loss-of-function assays (Cell Counting Kit-8 (CCK-8) assay, wound-healing scratch assay, transwell assay, and colony formation assay) further verified the activity of CTD-2288O8.1 in OC progression as well. Third, gene set enrichment analysis (GSEA) was applied along with the correlation analyses of CTD-2288O8.1 with ImmuneScore, tumor-infiltrating immune cells (TICs), and immune inhibitory checkpoint molecules, illustrating that CTD-2288O8.1 was strongly associated with the TIME and has the potential to predict the effect of OC immunotherapy. In addition, basic experiments demonstrated that the expression of CTD-2288O8.1 impacted the EGFR/AKT signal pathway activity of OC tumor cells. Of greater significance, it promoted the M2 polarization of macrophage, which is a type of the most important components of the TIME in solid tumor. Taking together, our study revealed cisplatin resistance-related lncRNAs closely linked with tumor immunity in OC, underscoring the potential mechanism of the TIME in conferring cisplatin resistance, which provided the research basis for further clinical treatment. CTD-2288O8.1 was identified to mediate cisplatin resistance and affect the response of immunotherapy, which could serve as a promising biomarker for guiding clinical treatment and improving prognosis in OC.

Identification of MAD2L1 as a Potential Biomarker in Hepatocellular Carcinoma via Comprehensive Bioinformatics Analysis

Background

Hepatocellular carcinoma (HCC) is widely acknowledged as a malignant tumor with rapid progression, high recurrence rate, and poor prognosis. At present, there is a paucity of reliable biomarkers at the clinical level to guide the management of HCC and improve patient outcomes. Our research is aimed at assessing the prognostic value of MAD2L1 in HCC.

Methods

Four datasets, GSE121248, GSE101685, GSE85598, and GSE62232, were selected from the GEO database to analyze differentially expressed genes (DEGs) between HCC and normal liver tissues. After functional analysis, we constructed a protein-protein interaction network (PPI) for DEGs and identified core genes in this network with high connectivity with other genes. We assessed the relationship between core genes and the pathogenesis and prognosis of HCC. Finally, we explored the gene regulatory signaling mechanisms involved in HCC pathogenesis.

Results

145 DEGs were screened from the intersection of the four GEO datasets. MAD2L1 was associated with most genes according to the PPI network and was selected as a candidate gene for further study. Survival analysis suggested that high MAD2L1 expression in HCC correlated with a worse prognosis. In addition, real-time quantitative PCR (RT-qPCR), western blot (WB), and immunohistochemistry (IHC) findings suggested that the expression of MAD2L1 was abnormally increased in HCC tissues and cells compared to paraneoplastic tissues and normal hepatocytes.

Conclusion

We found that high MAD2L1 expression in HCC was significantly associated with overall patient survival and clinical features. We also explored the potential biological properties of this gene.

The Systemic Inflammatory Response Identifies Patients with Adverse Clinical Outcome from Immunotherapy in Hepatocellular Carcinoma

Systemic inflammation is a hallmark of cancer, and it has a pivotal role in hepatocellular carcinoma (HCC) development and progression. We conducted a retrospective study including 362 patients receiving immune check-point inhibitors (ICIs) across three continents, evaluating the influence of neutrophiles to lymphocytes ratio (NLR), platelets to lymphocytes ratio (PLR), and prognostic nutritional index (PNI) on overall (OS), progression free survival (PFS), and radiologic responses. In our 362 patients treated with immunotherapy, median OS and PFS were 9 and 3.5 months, respectively. Amongst tested inflammatory biomarkers, patients with NLR ≥ 5 had shorter OS (7.7 vs. 17.6 months, p < 0.0001), PFS (2.1 vs. 3.8 months, p = 0.025), and lower objective response rate (ORR) (12% vs. 22%, p = 0.034); similarly, patients with PLR ≥ 300 reported shorter OS (6.4 vs. 16.5 months, p < 0.0001) and PFS (1.8 vs. 3.7 months, p = 0.0006). NLR emerged as independent prognostic factors for OS in univariate and multivariate analysis (HR 1.95, 95%CI 1.45-2.64, p < 0.001; HR 1.73, 95%CI 1.23-2.42, p = 0.002) and PLR remained an independent prognostic factor for both OS and PFS in multivariate analysis (HR 1.60, 95%CI 1.6-2.40, p = 0.020; HR 1.99, 95%CI 1.11-3.49, p = 0.021). Systemic inflammation measured by NLR and PLR is an independent negative prognostic factor in HCC patients undergoing ICI therapy. Further studies are required to understand the biological mechanisms underlying this association and to investigate the predictive significance of circulating inflammatory biomarkers in HCC patients treated with ICIs.

RNA Activation-A Novel Approach to Therapeutically Upregulate Gene Transcription

RNA activation (RNAa) is a mechanism whereby RNA oligos complementary to genomic sequences around the promoter region of genes increase the transcription output of their target gene. Small activating RNA (saRNA) mediate RNAa through interaction with protein co-factors to facilitate RNA polymerase II activity and nucleosome remodeling. As saRNA are small, versatile and safe, they represent a new class of therapeutics that can rescue the downregulation of critical genes in disease settings. This review highlights our current understanding of saRNA biology and describes various examples of how saRNA are successfully used to treat various oncological, neurological and monogenic diseases. MTL-CEBPA, a first-in-class compound that reverses CEBPA downregulation in oncogenic processes using CEBPA-51 saRNA has entered clinical trial for the treatment of hepatocellular carcinoma (HCC). Preclinical models demonstrate that MTL-CEBPA reverses the immunosuppressive effects of myeloid cells and allows for the synergistic enhancement of other anticancer drugs. Encouraging results led to the initiation of a clinical trial combining MTL-CEBPA with a PD-1 inhibitor for treatment of solid tumors.

Myeloid-Derived Suppressor Cells: A Propitious Road to Clinic

Myeloid-derived suppressor cells (MDSC) are important regulators of immune responses in cancer. They represent a relatively stable form of pathologic activation of neutrophils and monocytes and are characterized by distinct transcriptional, biochemical, functional, and phenotypical features. The close association of MDSCs with clinical outcomes in cancer suggests that these cells can be an attractive target for therapeutic intervention. However, the complex nature of MDSC biology represents a substantial challenge for the development of selective therapies. Here, we discuss the mechanisms regulating MDSC development and fate and recent research advances that have demonstrated opportunities for therapeutic regulation of these cells. SIGNIFICANCE: MDSCs are attractive therapeutic targets because of their close association with negative clinical outcomes in cancer and established biology as potent immunosuppressive cells. However, the complex nature of MDSC biology presents a substantial challenge for therapeutic targeting. In this review, we discuss those challenges and possible solutions.