Targeting KDM4C enhances CD8+ T cell mediated antitumor immunity by activating chemokine CXCL10 transcription in lung cancer

Research advances on signaling pathways regulating the polarization of tumor-associated macrophages in lung cancer microenvironment

Lung cancer (LC) is one of the most common cancer worldwide. Tumor-associated macrophages (TAMs) are important component of the tumor microenvironment (TME) and are closely related to the stages of tumor occurrence, development, and metastasis. Macrophages are plastic and can differentiate into different phenotypes and functions under the influence of different signaling pathways in TME. The classically activated (M1-like) and alternatively activated (M2-like) represent the two polarization states of macrophages. M1 macrophages exhibit anti-tumor functions, while M2 macrophages are considered to support tumor cell survival and metastasis. Macrophage polarization involves complex signaling pathways, and blocking or regulating these signaling pathways to enhance macrophages' anti-tumor effects has become a research hotspot in recent years. At the same time, there have been new discoveries regarding the modulation of TAMs towards an anti-tumor phenotype by synthetic and natural drug components. Nanotechnology can better achieve combination therapy and targeted delivery of drugs, maximizing the efficacy of the drugs while minimizing side effects. Up to now, nanomedicines targeting the delivery of various active substances for reprogramming TAMs have made significant progress. In this review, we primarily provided a comprehensive overview of the signaling crosstalk between TAMs and various cells in the LC microenvironment. Additionally, the latest advancements in novel drugs and nano-based drug delivery systems (NDDSs) that target macrophages were also reviewed. Finally, we discussed the prospects of macrophages as therapeutic targets and the barriers to clinical translation.

A pan-cancer interrogation of intronic polyadenylation and its association with cancer characteristics

3'UTR-APAs have been extensively studied, but intronic polyadenylations (IPAs) remain largely unexplored. We characterized the profiles of 22 260 IPAs in 9679 patient samples across 32 cancer types from the Cancer Genome Atlas cohort. By comparing tumor and paired normal tissues, we identified 180 ~ 4645 dysregulated IPAs in 132 ~ 2249 genes in each of 690 patient tumors from 22 cancer types that showed consistent patterns within individual cancer types. We selected 2741 genes that showed consistently patterns across cancer types, including 1834 pan-cancer tumor-enriched and 907 tumor-depleted IPA genes; the former were amply represented in the functional pathways such as deoxyribonucleic acid damage repair. Expression of IPA isoforms was associated with tumor mutation burden and patient characteristics (e.g. sex, race, cancer stages, and subtypes) in cancer-specific and feature-specific manners, and could be a more accurate prognostic marker than gene expression (summary of all isoforms). In summary, our study reveals the roles and the clinical relevance of tumor-associated IPAs.

CXCL5 impedes CD8+ T cell immunity by upregulating PD-L1 expression in lung cancer via PXN/AKT signaling phosphorylation and neutrophil chemotaxis

BACKGROUND

Lung cancer remains one of the most prevalent cancer types worldwide, with a high mortality rate. Upregulation of programmed cell death protein 1 (PD-1) and its ligand (PD-L1) may represent a key mechanism for evading immune surveillance. Immune checkpoint blockade (ICB) antibodies against PD-1 or PD-L1 are therefore widely used to treat patients with lung cancer. However, the mechanisms by which lung cancer and neutrophils in the microenvironment sustain PD-L1 expression and impart stronger inhibition of CD8+ T cell function remain unclear.

METHODS

We investigated the role and underlying mechanism by which PD-L1+ lung cancer and PD-L1+ neutrophils impede the function of CD8+ T cells through magnetic bead cell sorting, quantitative real-time polymerase chain reaction (RT-PCR), western blotting, enzyme-linked immunosorbent assays, confocal immunofluorescence, gene silencing, flow cytometry, etc. In vivo efficacy and safety studies were conducted using (Non-obeseDiabetes/severe combined immune deficiency) SCID/NOD mice. Additionally, we collected clinical and prognostic data from 208 patients who underwent curative lung cancer resection between 2017 and 2018.

RESULTS

We demonstrated that C-X-C motif chemokine ligand 5 (CXCL5) is markedly overexpressed in lung cancer cells and is positively correlated with a poor prognosis in patients with lung cancer. Mechanistically, CXCL5 activates the phosphorylation of the Paxillin/AKT signaling cascade, leading to upregulation of PD-L1 expression and the formation of a positive feedback loop. Moreover, CXCL5 attracts neutrophils, compromising CD8+ T cell-dependent antitumor immunity. These PD-L1+ neutrophils aggravate CD8+ T cell exhaustion following lung cancer domestication. Combined treatment with anti-CXCL5 and anti-PD-L1 antibodies significantly inhibits tumor growth in vivo.

CONCLUSIONS

Our findings collectively demonstrate that CXCL5 promotes immune escape through PD-L1 upregulation in lung cancer and neutrophils chemotaxis through autocrine and paracrine mechanisms. CXCL5 may serve as a potential therapeutic target in synergy with ICBs in lung cancer immunotherapy.

Developing a prognostic model for skin melanoma based on the persistent tumor mutation burden and determining IL17REL as a therapeutic target

BACKGROUND

One popular and well-established marker for the immune checkpoint blockade (ICB) response is tumor mutation burden (TMB). Persistent TMB (pTMB), a subset of TMB, provides a better indicator to predict patient ICB therapy outcomes, as shown by some studies. Immune checkpoint drugs have significantly changed how melanoma is treated in recent years.

METHODS

In this study, we integrated the TCGA-SKCM database and data of pTMB of TCGA from the paper that first mentioned pTMB and analyzed mutational and Immune characteristics associated with pTMB level in SKCM. Next, the predictive DEGs were identified the subgroups of pTMB by Cox regression and LASSO analyses to construct a pTMB-related signature. Finally, the expression and Biological functions of signature genes was detected, and further validated in vitro assay.

RESULTS

In the current research, we explored the mutational and immunological features related to the level of TMB in cutaneous melanoma (CM). The high-pTMB subgroup exhibited an increasing incidence of gene changes and higher levels of immune cell infiltration. Subsequently, we established a pTMB-related signature based on the predictive DEGs and found the biological features and immune-associated variables between two distinct risk groups. Lastly, the results of the clinical sample validation demonstrated that the expression of IL17REL was down-regulated in the collected samples of individuals with CM. The in vitro assay results indicated that IL17REL effectively suppressed the proliferation, clonality, and migration of CM cells.

CONCLUSION

In conclusion, we have developed a prediction model associated with TMB and subsequently validated the potential influence of IL17REL on Overall Survival (OS) in patients diagnosed with melanoma.

DC-derived CXCL10 promotes CTL activation to suppress ovarian cancer

This study investigates the role of dendritic cells (DCs), with a focus on their CXCL10 marker gene, in the activation of cytotoxic T lymphocytes (CTLs) within the ovarian cancer microenvironment and its impact on disease progression. Utilizing scRNA-seq data and immune infiltration analysis, we identified a diminished DC presence in ovarian cancer. Gene analysis pinpointed CXCL10 as a key regulator in OV progression via its influence on DCs and CTLs. Prognostic analysis and in vitro experiments substantiated this role. Our findings reveal that DC-derived CXCL10 significantly affects CTL activation and proliferation. Reduced CXCL10 levels hinder CTL cytotoxicity, promoting ovarian cancer cell migration and invasion. Experimental studies using animal models have provided further evidence that the capacity of CTLs to suppress tumor development is significantly diminished when treated with DCs that have low expression of CXCL10. Dendritic cell-derived CXCL10 emerges as a pivotal factor in restraining ovarian cancer growth and metastasis through the activation of cytotoxic T lymphocytes. This study sheds light on the crucial interplay within the ovarian cancer microenvironment, offering potential therapeutic targets for ovarian cancer treatment.

USP9X-mediated REV1 deubiquitination promotes lung cancer radioresistance via the action of REV1 as a Rad18 molecular scaffold for cystathionine γ-lyase

BACKGROUND

Radioresistance is a key clinical constraint on the efficacy of radiotherapy in lung cancer patients. REV1 DNA directed polymerase (REV1) plays an important role in repairing DNA damage and maintaining genomic stability. However, its role in the resistance to radiotherapy in lung cancer is not clear. This study aims to clarify the role of REV1 in lung cancer radioresistance, identify the intrinsic mechanisms involved, and provide a theoretical basis for the clinical translation of this new target for lung cancer treatment.

METHODS

The effect of targeting REV1 on the radiosensitivity was verified by in vivo and in vitro experiments. RNA sequencing (RNA-seq) combined with nontargeted metabolomics analysis was used to explore the downstream targets of REV1. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to quantify the content of specific amino acids. The coimmunoprecipitation (co-IP) and GST pull-down assays were used to validate the interaction between proteins. A ubiquitination library screening system was constructed to investigate the regulatory proteins upstream of REV1.

RESULTS

Targeting REV1 could enhance the radiosensitivity in vivo, while this effect was not obvious in vitro. RNA sequencing combined with nontargeted metabolomics revealed that the difference result was related to metabolism, and that the expression of glycine, serine, and threonine (Gly/Ser/Thr) metabolism signaling pathways was downregulated following REV1 knockdown. LC-MS/MS demonstrated that REV1 knockdown results in reduced levels of these three amino acids and that cystathionine γ-lyase (CTH) was the key to its function. REV1 enhances the interaction of CTH with the E3 ubiquitin ligase Rad18 and promotes ubiquitination degradation of CTH by Rad18. Screening of the ubiquitination compound library revealed that the ubiquitin-specific peptidase 9 X-linked (USP9X) is the upstream regulatory protein of REV1 by the ubiquitin-proteasome system, which remodels the intracellular Gly/Ser/Thr metabolism.

CONCLUSION

USP9X mediates the deubiquitination of REV1, and aberrantly expressed REV1 acts as a scaffolding protein to assist Rad18 in interacting with CTH, promoting the ubiquitination and degradation of CTH and inducing remodeling of the Gly/Ser/Thr metabolism, which leads to radioresistance. A novel inhibitor of REV1, JH-RE-06, was shown to enhance lung cancer cell radiosensitivity, with good prospects for clinical translation.

CXCL10 and IL15 co-expressing chimeric antigen receptor T cells enhance anti-tumor effects in gastric cancer by increasing cytotoxic effector cell accumulation and survival

Chimeric antigen receptor (CAR) T cells have demonstrated outstanding therapeutic success in hematological malignancies. Yet, their efficacy against solid tumors remains constrained due to inadequate infiltration of cytotoxic T and CAR-T cells in the tumor microenvironment (TME), a factor correlated with poor prognosis in patients with solid tumors. To overcome this limitation, we engineered CAR-T cells to secrete CXCL10 and IL15 (10 × 15 CAR-T), which sustain T cell viability and enhance their recruitment, thereby amplifying the long-term cytotoxic capacity of CAR-T cells in vitro. In a xenograft model employing NUGC4-T21 cells, mice receiving 10 × 15 CAR-T cells showed superior tumor reduction and extended survival rates compared to those treated with second-generation CAR-T cells. Histopathological evaluations indicated a pronounced increase in cytotoxic T cell accumulation in the TME post 10 × 15 CAR-T cell treatment. Therefore, the synergistic secretion of CXCL10 and IL15 in these CAR-T cells enhances T cell recruitment and adaptability within tumor tissues, improving tumor control. This approach may offer a promising strategy for advancing CAR-T therapies in the treatment of solid tumors.

Exercise accelerates recruitment of CD8+ T cell to promotes anti-tumor immunity in lung cancer via epinephrine

BACKGROUND AND PURPOSE

In recent years, there has been extensive research on the role of exercise as an adjunctive therapy for cancer. However, the potential mechanisms underlying the anti-tumor therapy of exercise in lung cancer remain to be fully elucidated. As such, our study aims to confirm whether exercise-induced elevation of epinephrine can accelerate CD8+ T cell recruitment through modulation of chemokines and thus ultimately inhibit tumor progression.

METHOD

C57BL/6 mice were subcutaneously inoculated with Lewis lung cancer cells (LLCs) to establish a subcutaneous tumor model. The tumor mice were randomly divided into different groups to performed a moderate-intensity exercise program on a treadmill for 5 consecutive days a week, 45 min a day. The blood samples and tumor tissues were collected after exercise for IHC, RT-qPCR, ELISA and Western blot. In addition, another group of mice received daily epinephrine treatment for two weeks (0.05 mg/mL, 200 µL i.p.) (EPI, n = 8) to replicate the effects of exercise on tumors in vivo. Lewis lung cancer cells were treated with different concentrations of epinephrine (0, 5, 10, 20 µM) to detect the effect of epinephrine on chemokine levels via ELISA and RT-qPCR.

RESULTS

This study reveals that both pre- and post-cancer exercise effectively impede the tumor progression. Exercise led to an increase in EPI levels and the infiltration of CD8+ T cell into the lung tumor. Exercise-induced elevation of EPI is involved in the regulation of Ccl5 and Cxcl10 levels further leading to enhanced CD8+ T cell infiltration and ultimately inhibiting tumor progression.

CONCLUSION

Exercise training enhance the anti-tumor immunity of lung cancer individuals. These findings will provide valuable insights for the future application of exercise therapy in clinical practice.

PARP inhibitor plus radiotherapy reshape the immune suppressive microenvironment and potentiate the efficacy of immune checkpoint inhibitors in tumors with IDH1 mutation

Isocitrate dehydrogenase 1 mutant (IDH1mut) tumors respond poorly to immunotherapy, but are more sensitive to chemoradiotherapy and poly (ADP-ribose) polymerase inhibition (PARPi). Accordingly, some efforts have aimed to capitalize on the IDH1 mutation rather than reverse it. Moreover, radiotherapy (RT) and PARPi can stimulate antitumor immunity, raising the possibility of reversing the immunosuppression caused by IDH1 mutation while killing the tumor. To assess this possibility, we treated IDH1mut tumors and cells with RT + PARPi. RT + PARPi showed enhanced efficacy over either modality alone both in vitro and in vivo. RT + PARPi induced more DNA damage and activated the cGAS-STING pathway more. IFNβ, CXCL10, and CCL5 were also more highly expressed at both the mRNA and protein levels. In two different tumor models, RT + PARPi increased infiltration and cytolytic function of CD8+ T cells, with one model also showing increased CD8+T cell proliferation. RT+PARPi also increased PD-L1 expression and enhanced checkpoint inhibition. Knocking out cGAS reversed the increased CD8+ T cell infiltration and the antitumor effect of RT+PARPi. We conclude that RT + PARPi reshapes the IDH1mut tumor immunosuppressive microenvironment, thereby augmenting checkpoint inhibition.

CDKL1 potentiates the antitumor efficacy of radioimmunotherapy by binding to transcription factor YBX1 and blocking PD-L1 expression in lung cancer

BACKGROUND

The evasion of the immune response by tumor cells through programmed death-ligand 1 (PD-L1) has been identified as a factor contributing to resistance to radioimmunotherapy in lung cancer patients. However, the precise molecular mechanisms underlying the regulation of PD-L1 remain incompletely understood. This study aimed to investigate the role of cyclin-dependent kinase-like 1 (CDKL1) in the modulation of PD-L1 expression and the response to radioimmunotherapy in lung cancer.

METHODS

The tumorigenic roles of CDKL1 were assessed via cell growth, colony formation, and EdU assays and an in vivo nude mouse xenograft model. The in vitro radiosensitization effect of CDKL1 was evaluated using a neutral comet assay, γH2AX foci formation analysis, and a clonogenic cell survival assay. The protein‒protein interactions were confirmed via coimmunoprecipitation and GST pulldown assays. The regulation of PD-L1 by CDKL1 was evaluated via chromatin immunoprecipitation (ChIP), real-time quantitative PCR, and flow cytometry analysis. An in vitro conditioned culture model and an in vivo C57BL/6J mouse xenograft model were developed to detect the activation markers of CD8+ T cells and evaluate the efficacy of CDKL1 overexpression combined with radiotherapy (RT) and an anti-PD-L1 antibody in treating lung cancer.

RESULTS

CDKL1 was downregulated and suppressed the growth and proliferation of lung cancer cells and increased radiosensitivity in vitro and in vivo. Mechanistically, CDKL1 interacted with the transcription factor YBX1 and decreased the binding affinity of YBX1 for the PD-L1 gene promoter, which consequently inhibits the expression of PD-L1, ultimately leading to the activation of CD8+ T cells and the inhibition of immune evasion in lung cancer. Moreover, the combination of CDKL1 overexpression, RT, and anti-PD-L1 antibody therapy exhibited the most potent antitumor efficacy against lung cancer.

CONCLUSIONS

Our findings demonstrate that CDKL1 plays a crucial role in regulating PD-L1 expression, thereby enhancing the antitumor effects of radioimmunotherapy. These results suggest that CDKL1 may be a promising therapeutic target for the treatment of lung cancer.

Silencing PinX1 enhances radiosensitivity and antitumor-immunity of radiotherapy in non-small cell lung cancer

BACKGROUND

We aimed to investigate the effects of PinX1 on non-small cell lung cancer(NSCLC) radiosensitivity and radiotherapy-associated tumor immune microenvironment and its mechanisms.

METHODS

The effect of PinX1 silencing on radiosensitivity in NSCLC was assessed by colony formation and CCK8 assay, immunofluorescence detection of γ- H2AX and micronucleus assay. Western blot was used to assess the effect of PinX1 silencing on DNA damage repair pathway and cGAS-STING pathway. The nude mouse and Lewis lung cancer mouse model were used to assess the combined efficacy of PinX1 silencing and radiotherapy in vivo. Changes in the tumor immune microenvironment were assessed by flow cytometry for different treatment modalities in the Lewis luuse model. The interaction protein RBM10 was screened by immunoprecipitation-mass spectrometry.

RESULTS

Silencing PinX1 enhanced radiosensitivity and activation of the cGAS-STING pathway while attenuating the DNA damage repair pathway. Silencing PinX1 further increases radiotherapy-stimulated CD8+ T cell infiltration and activation, enhances tumor control and improves survival in vivo; Moreover, PinX1 downregulation improves the anti-tumor efficacy of radioimmunotherapy, increases radioimmune-stimulated CD8+ T cell infiltration, and reprograms M2-type macrophages into M1-type macrophages in tumor tissues. The interaction of PinX1 and RBM10 may promote telomere maintenance by assisting telomerase localization to telomeres, thereby inhibiting the immunostimulatory effects of IR.

CONCLUSIONS

In NSCLC, silencing PinX1 significantly contributed to the radiosensitivity and promoted the efficacy of radioimmunotherapy. Mechanistically, PinX1 may regulate the transport of telomerase to telomeres through interacting with RBM10, which promotes telomere maintenance and DNA stabilization. Our findings reveal that PinX1 is a potential target to enhance the efficacy of radioimmunotherapy in NSCLC patients.

CircMAPK1 promoted CD8 + T cell infiltration in LUAD by improving the IGF2BP1 dependent CCL5 upregulation

Lung adenocarcinoma (LUAD) is the most common pathological subtype of lung cancer and has a poor prognosis. Immune Checkpoint Blockage (ICB) have been shown to improve the survival of LUAD in the last decade. CD8 + T cell infiltration is significantly related to LUAD prognosis and plays a critical role in ICB response efficiency. Chemokines expressed and secreted by tumor and microenvironment cells regulate the recruitment of CD8 + T cells. A cytoplasm-dominant circRNA, termed circMAPK1, was found to be down-regulated in LUAD and dramatically suppressed the growth of LUAD upon circMAPK1 overexpression in immunocompetent mice. Meanwhile, it was found that circMAPK1 significantly promoted the CD8 + T cell intratumoral infiltration in vitro and in vivo. CircMAPK1 was identified as binding IGF2BP1 in the cytoplasm and inducing IGF2BP1 to occupy the 3'UTR of CCL5 mRNA, resulting in retained stability of CCL5 mRNA. In general, circMAPK1 is a microenvironment-associated circRNA that recruits CD8 + T cells in LUAD. CircMAPK1 is an effective microenvironment regulator and a potential nucleic acid drug that can be combined with ICB to improve immunotherapy response efficiency.

Infection of tumor cells with Salmonella typhimurium mimics immunogenic cell death and elicits tumor-specific immune responses

Some properties of Salmonella-infected cells overlap with immunogenic cell death. In this study, we demonstrated that intracellular infection of melanoma with Salmonella typhimurium induced high immunogenicity in melanoma cells, leading to antitumor effects with melanoma-antigen-specific T-cell responses. Murine B16F10 melanoma cells were infected with tdTomato-expressing attenuated S. typhimurium (VNP20009; VNP-tdT), triggering massive cell vacuolization. VNP-tdT-infected B16F10 cells were phagocytosed efficiently, which induced the activation of antigen-presenting cells with CD86 expression in vitro. Subcutaneous coimplantation of uninfected and VNP-tdT-infected B16F10 cells into C57BL/6 mice significantly suppressed tumor growth compared with the implantation of uninfected B16F10 cells alone. Inoculation of mice with VNP-tdT-infected B16F10 cells elicited the proliferation of melanoma-antigen (gp100)-specific T cells, and it protected the mice from the second tumor challenge of uninfected B16F10 cells. These results suggest that Salmonella-infected tumor cells acquire effective adjuvanticity, leading to ideal antitumor immune responses.

FEN1 inhibitor SC13 promotes CAR-T cells infiltration into solid tumours through cGAS-STING signalling pathway

It is well known that chimeric antigen receptor T-cell immunotherapy (CAR-T-cell immunotherapy) has excellent therapeutic effect in haematological tumours, but it still faces great challenges in solid tumours, including inefficient T-cell tumour infiltration and poor functional persistence. Flap structure-specific endonuclease 1 (FEN1), highly expressed in a variety of cancer cells, plays an important role in both DNA replication and repair. Previous studies have reported that FEN1 inhibition is an effective strategy for cancer treatment. Therefore, we hypothesized whether FEN1 inhibitors combined with CAR-T-cell immunotherapy would have a stronger killing effect on solid tumours. The results showed that low dose of FEN1 inhibitors SC13 could induce an increase of double-stranded broken DNA (dsDNA) in the cytoplasm. Cytosolic dsDNA can activate the cyclic GMP-AMP synthase-stimulator of interferon gene signalling pathway and increase the secretion of chemokines. In vivo, under the action of FEN1 inhibitor SC13, more chemokines were produced at solid tumour sites, which promoted the infiltration of CAR-T cells and improved anti-tumour immunity. These findings suggest that FEN1 inhibitors could enable CAR-T cells to overcome poor T-cell infiltration and improve the treatment of solid tumours.

Tespa1 deficiency reduces the antitumour immune response by decreasing CD8+T cell activity in a mouse Lewis lung cancer model

Thymocyte-expressed, positive selection-associated 1 (Tespa1) is a key molecule in T-cell development and has been linked to immune diseases. However, its role in antitumour CD8+T cell immunity remains unclear. Here, we demonstrated that Tespa1 plays an important role in antitumour CD8+T cell immunity. First, compared with wild-type (WT) mice, Lewis lung cancer cells grew faster in Tespa1 knockout (Tespa1-/-) mice, with reduced apoptosis, and decreased CD8+T cells in peripheral blood and tumor tissues. Second, the proportion of CD8+T and Th1 cells in the splenocytes of Tespa1-/- mice was lower than that in WT mice. Third, Tespa1-/- CD8+ tumor-infiltrating lymphocytes (TILs) showed weakened proliferation, invasion, cytotoxicity, and protein expression of IL-2 signalling pathway components compared to WT CD8+TILs. Furthermore, PD-1 expression in CD8+TILs was higher in Tespa1-/- than in WT mice. Lastly, CD8+TILs in WT mice improved the antitumour ability of Tespa1-/- mice. In conclusion, these findings suggest that Tespa1 plays a critical role in the tumor immune system by regulating CD8+T cells.

GAS-STING: a classical DNA recognition pathways to tumor therapy

Cyclic GMP-AMP synthetase (cGAS), recognized as the primary DNA sensor within cells, possesses the capability to identify foreign DNA molecules along with free DNA fragments. This identification process facilitates the production of type I IFNs through the activator of the interferon gene (STING) which induces the phosphorylation of downstream transcription factors. This action characterizes the most archetypal biological functionality of the cGAS-STING pathway. When treated with anti-tumor agents, cells experience DNA damage that triggers activation of the cGAS-STING pathway, culminating in the expression of type I IFNs and associated downstream interferon-stimulated genes. cGAS-STING is one of the important innate immune pathways,the role of type I IFNs in the articulation between innate immunity and T-cell antitumour immunity.type I IFNs promote the recruitment and activation of inflammatory cells (including NK cells) at the tumor site.Type I IFNs also can promote the activation and maturation of dendritic cel(DC), improve the antigen presentation of CD4+T lymphocytes, and enhance the cross-presentation of CD8+T lymphocytes to upregulating anti-tumor responses. This review discussed the cGAS-STING signaling and its mechanism and biological function in traditional tumor therapy and immunotherapy.

Non-immune cell components in tumor microenvironment influencing lung cancer Immunotherapy

Lung cancer (LC) is one of the leading causes of cancer-related deaths worldwide, with a significant morbidity and mortality rate, endangering human life and health. The introduction of immunotherapies has significantly altered existing cancer treatment strategies and is expected to improve immune responses, objective response rates, and survival rates. However, a better understanding of the complex immunological networks of LC is required to improve immunotherapy efficacy further. Tumor-associated antigens (TAAs) and tumor-specific antigens (TSAs) are significantly expressed by LC cells, which activate dendritic cells, initiate antigen presentation, and activate lymphocytes to exert antitumor activity. However, as tumor cells combat the immune system, an immunosuppressive microenvironment forms, enabling the enactment of a series of immunological escape mechanisms, including the recruitment of immunosuppressive cells and induction of T cell exhaustion to decrease the antitumor immune response. In addition to the direct effect of LC cells on immune cell function, the secreting various cytokines, chemokines, and exosomes, changes in the intratumoral microbiome and the function of cancer-associated fibroblasts and endothelial cells contribute to LC cell immune escape. Accordingly, combining various immunotherapies with other therapies can elicit synergistic effects based on the complex immune network, improving immunotherapy efficacy through multi-target action on the tumor microenvironment (TME). Hence, this review provides guidance for understanding the complex immune network in the TME and designing novel and effective immunotherapy strategies for LC.

Immune checkpoint therapy for solid tumours: clinical dilemmas and future trends

Immune-checkpoint inhibitors (ICBs), in addition to targeting CTLA-4, PD-1, and PD-L1, novel targeting LAG-3 drugs have also been approved in clinical application. With the widespread use of the drug, we must deeply analyze the dilemma of the agents and seek a breakthrough in the treatment prospect. Over the past decades, these agents have demonstrated dramatic efficacy, especially in patients with melanoma and non-small cell lung cancer (NSCLC). Nonetheless, in the field of a broad concept of solid tumours, non-specific indications, inseparable immune response and side effects, unconfirmed progressive disease, and complex regulatory networks of immune resistance are four barriers that limit its widespread application. Fortunately, the successful clinical trials of novel ICB agents and combination therapies, the advent of the era of oncolytic virus gene editing, and the breakthrough of the technical barriers of mRNA vaccines and nano-delivery systems have made remarkable breakthroughs currently. In this review, we enumerate the mechanisms of each immune checkpoint targets, associations between ICB with tumour mutation burden, key immune regulatory or resistance signalling pathways, the specific clinical evidence of the efficacy of classical targets and new targets among different tumour types and put forward dialectical thoughts on drug safety. Finally, we discuss the importance of accurate triage of ICB based on recent advances in predictive biomarkers and diagnostic testing techniques.

Carcinogenesis promotion in oral squamous cell carcinoma: KDM4A complex-mediated gene transcriptional suppression by LEF1

Oral squamous cell carcinoma (OSCC) is the most prevalent cancer of the mouth, characterised by rapid progression and poor prognosis. Hence, an urgent need exists for the development of predictive targets for early diagnosis, prognosis determination, and clinical therapy. Dysregulation of lymphoid enhancer-binding factor 1 (LEF1), an important transcription factor involved in the Wnt-β-catenin pathway, contributes to the poor prognosis of OSCC. Herein, we aimed to explore the correlation between LEF1 and histone lysine demethylase 4 A (KDM4A). Results show that the KDM4A complex is recruited by LEF1 and specifically binds the LATS2 promoter region, thereby inhibiting its expression, and consequently promoting cell proliferation and impeding apoptosis in OSCC. We also established NOD/SCID mouse xenograft models using CAL-27 cells to conduct an in vivo analysis of the roles of LEF1 and KDM4A in tumour growth, and our findings show that cells stably suppressing LEF1 or KDM4A have markedly decreased tumour-initiating capacity. Overall, the results of this study demonstrate that LEF1 plays a pivotal role in OSCC development and has potential to serve as a target for early diagnosis and treatment of OSCC.

Histone demethylases in the regulation of immunity and inflammation

Pathogens or danger signals trigger the immune response. Moderate immune response activation removes pathogens and avoids excessive inflammation and tissue damage. Histone demethylases (KDMs) regulate gene expression and play essential roles in numerous physiological processes by removing methyl groups from lysine residues on target proteins. Abnormal expression of KDMs is closely associated with the pathogenesis of various inflammatory diseases such as liver fibrosis, lung injury, and autoimmune diseases. Despite becoming exciting targets for diagnosing and treating these diseases, the role of these enzymes in the regulation of immune and inflammatory response is still unclear. Here, we review the underlying mechanisms through which KDMs regulate immune-related pathways and inflammatory responses. In addition, we also discuss the future applications of KDMs inhibitors in immune and inflammatory diseases.

RNA demethylase ALKBH5 suppresses tumorigenesis via inhibiting proliferation and invasion and promoting CD8+ T cell infiltration in colorectal cancer

BACKGROUND

ALKBH5 belongs to the ALKB family consists of a Fe (II) and a-ketoglutarate-dependent dioxygenase. ALKBH5 directly catalyzes the oxidative demethylation of m6A-methylated adenosine. ALKBH5 involves in tumorigenesis and tumor progression, and is often dysregulated in a wide range of cancers, including colorectal cancer. Emerging evidence indicates that the expression of ALKBH5 is associated with the abundance of infiltrating immune cells in the microenvironment. However, how ALKBH5 affects immune cell infiltration in the microenvironment in colorectal cancer (CRC) has not been reported. The aim of this study was to identify how the expression of ALKBH5 affects the biological behaviors of CRC cell lines and regulates the effects on infiltrating CD8⁺ T cells in CRC microenvironment with its specific mechanism.

METHODS

Firstly, the transcriptional expression profiles of CRC were downloaded from TCGA database and integrated via R software (4.1.2). Between CRC and normal colorectal tissues, ALKBH5 mRNA expressions were compared (Wilcoxon rank-sum). We further identified the expression levels of ALKBH5 in CRC tissues and cell lines through quantitative PCR, western blot, and immunohistochemistry. Then, how ALKBH5 affects the biological behaviors of CRC cells were confirmed by gain- and loss-of-function analysis. Furthermore, the relationship between ALKBH5 level and 22 tumor-infiltrating immune cells was examined through CIBERSORT in R software. Furthermore, we explored the correlation between ALKBH5 expression and tumor-infiltrated CD8⁺, CD4⁺ and regulatory T cells by utilizing the TIMER database. Finally, the association between chemokines and CD8⁺ T cells infiltration in CRC was analyzed using GEPIA online database. qRT-PCR, WB and IHC were used to further determine the effect of ALKBH5 on NF-κB-CCL5 signaling axis and CD8⁺ T cells infiltration.

RESULTS

Clinically, ALKBH5 expression was downregulated in CRC and low levels of ALKBH5 expression were correlated with poor overall survival (OS). Functionally, overexpression of ALKBH5 reduced the proliferation, migration and invasion of CRC cells, and vice versa. Overexpression of ALKBH5 suppresses NF-κB pathway, thus reduces CCL5 expression and promotes CD8⁺ T cells infiltration in CRC microenvironment.

CONCLUSIONS

ALKBH5 is poorly expressed in CRC, and overexpression of ALKBH5 attenuates CRC malignant progression by inhibiting CRC cell proliferation, migration, invasion and promoting CD8⁺ T cells infiltration in the tumor microenvironment through NF-κB-CCL5 axis.

KDM4C silencing inhibits cell migration and enhances radiosensitivity by inducing CXCL2 transcription in hepatocellular carcinoma

KDM4C, which is a histone lysine demethylase, has been proposed to participate in the malignant transformation and progression of several types of cancer. However, its roles in hepatocellular carcinoma (HCC) remain poorly understood. Here, we find that KDM4C protein expression is increased in HCC and promotes HCC cell growth, proliferation and migration. Furthermore, we provide evidence that depletion of KDM4C leads to a defective G2/M checkpoint, increases radiation-induced DNA damage, impairs DNA repair and enhances radiosensitivity in HCC cells. Using RNA sequencing, we identify that the chemokine CXCL2 is a downstream effector of KDM4C. KDM4C knockdown increases the binding of H3K36me3 to the promoter of CXCL2, thus upregulating CXCL2 expression and promoting CXCL2 secretion in HCC cells. Importantly, the observed effects of KDM4C depletion in HCC cells can be partially rescued by CXCL2 silencing. Thus, our findings reveal that KDM4C is involved in cell migration and radiosensitivity by modulating CXCL2 transcription, indicating that KDM4C may be a potential therapeutic target in HCC.

The role of histone methylase and demethylase in antitumor immunity: A new direction for immunotherapy

Epigenetic modifications may alter the proliferation and differentiation of normal cells, leading to malignant transformation. They can also affect normal stimulation, activation, and abnormal function of immune cells in the tissue microenvironment. Histone methylation, coordinated by histone methylase and histone demethylase to stabilize transcription levels in the promoter area, is one of the most common types of epigenetic alteration, which gained increasing interest. It can modify gene transcription through chromatin structure and affect cell fate, at the transcriptome or protein level. According to recent research, histone methylation modification can regulate tumor and immune cells affecting anti-tumor immune response. Consequently, it is critical to have a thorough grasp of the role of methylation function in cancer treatment. In this review, we discussed recent data on the mechanisms of histone methylation on factors associated with immune resistance of tumor cells and regulation of immune cell function.

Anlotinib enhances the antitumor immunity of radiotherapy by activating cGAS/STING in non-small cell lung cancer

Radiation resistance and unsatisfactory efficacy of radioimmunotherapy are important barriers to non-small cell lung cancer (NSCLC) treatment. The impacts of anlotinib on radiation and tumor immune microenvironment (TIME) in NSCLC remain to be resolved. Here, we find anlotinib enhances radiosensitivity, and further increases radiotherapy-stimulated CD8+ T cell infiltration and activation via triggering cGAS/STING pathway. Moreover, anlotinib shows significant effects on radioimmunotherapy (radiotherapy plus anti-PD-L1). The addition of anlotinib alleviates CD8+ T cell exhaustion, promotes the cytotoxicity and proliferation of CD8+ T cells, and boosts immune memory activation. Our work reveals the crucial role of anlotinib in antitumor immunity, and provides preclinical evidence for the application of anlotinib combined with radioimmunotherapy in NSCLC treatment.

A Novel Prognostic Chemokine-Related lncRNAs Signature Associated with Immune Landscape in Colon Adenocarcinoma

Chemokines have been reported to be involved in tumorigenesis and progression and can also modulate the tumor microenvironment. However, it is still unclear whether chemokine-related long noncoding RNAs (lncRNAs) can affect the prognosis of colon adenocarcinoma (COAD). We summarized chemokine-related genes and downloaded RNA-seq and clinical data from The Cancer Genome Atlas (TCGA) database. A total of 52 prognostic chemokine-related lncRNAs were screened by univariate Cox regression analysis; patients were grouped according to cluster analysis results. Lasso regression analysis was applied to determine chemokine-related lncRNAs to construct a risk model for further research. This study first investigated the differences between the prognosis and immune status of two chemokine-related lncRNAs clusters by consensus clustering. Then, using various algorithms, we obtained ten chemokine-related lncRNAs to construct a new prognostic chemokine-related lncRNAs risk model. The risk model's predictive efficiency, validity, and accuracy were further validated and determined in the test and training cohorts. Furthermore, this risk model played a vital role in predicting immune cell infiltration, immune checkpoint gene expression, tumor mutational burden (TMB), immunotherapy score, and drug sensitivity in COAD patients. These findings elucidated the critical role of novel prognostic chemokine-related lncRNAs in prognosis, immune landscape, and drug therapy, thereby providing valuable insights for prognosis assessment and personalized treatment strategies for COAD patients.

Analysis of immune status in gastric adenocarcinoma with different infiltrating patterns and origin sites

Tumor infiltration pattern (INF) and tumor origin site were reported to significantly affect the prognosis of gastric cancer (GC), while the immune status under these contexts is not clear. In this study, we correlated the density and phenotype of tumor-infiltrating lymphocytes (TILs) with INF and the tumor origin site to reflect the biological behavior of tumors from a new perspective and also determined their effects on overall survival (OS) and other related clinicopathological features in archival samples of 147 gastric cancers with 10-year follow-up data. We found that the INFc growth pattern (an invasive growth without a distinct border) of GC lacked immune cell infiltration, particularly the cytotoxic T cells and their activated form. It is also significantly associated with an unfavorable prognosis (P < 0.001) and proximal site (P = 0.001), positive lymph node metastasis (P = 0.002), and later tumor–node–metastasis stage (P < 0.001). Moreover, the density and sub-type of TILs infiltration were significantly different in disparate differentiated areas for the tumor tissue with INFb. Compared with distal gastric cancer, proximal gastric cancers were prone to grow in an INFc pattern (P = 0.001) and infiltrated with fewer TILs, experiencing a shorter survival time (P = 0.013). Multivariate analysis showed that only the INF and the density of TILs were demonstrated to be the independent prognostic factors of OS for the GC. We concluded that GC with an aggressive growth pattern arising from proximal sites always had a weak immune response and resulted in a poor prognosis. The interaction between them and their synergistic or antagonistic effects in the development of tumors need to be further studied. This study opens up a new perspective for research on the biological behavior of the tumor.

Activated amino acid response pathway generates apatinib resistance by reprograming glutamine metabolism in non-small-cell lung cancer

The efficacy of apatinib has been confirmed in the treatment of solid tumors, including non-small-cell lung cancer (NSCLC). However, the direct functional mechanisms of tumor lethality mediated by apatinib and the precise mechanisms of drug resistance are largely unknown. In this study, we demonstrated that apatinib could reprogram glutamine metabolism in human NSCLC via a mechanism involved in amino acid metabolic imbalances. Apatinib repressed the expression of GLS1, the initial and rate-limiting enzyme of glutamine catabolism. However, the broken metabolic balance led to the activation of the amino acid response (AAR) pathway, known as the GCN2/eIF2α/ATF4 pathway. Moreover, activation of ATF4 was responsible for the induction of SLC1A5 and ASNS, which promoted the consumption and metabolization of glutamine. Interestingly, the combination of apatinib and ATF4 silencing abolished glutamine metabolism in NSCLC cells. Moreover, knockdown of ATF4 enhanced the antitumor effect of apatinib both in vitro and in vivo. In summary, this study showed that apatinib could reprogram glutamine metabolism through the activation of the AAR pathway in human NSCLC cells and indicated that targeting ATF4 is a potential therapeutic strategy for relieving apatinib resistance.

Role of chemokine systems in cancer and inflammatory diseases

Chemokines are a large family of small secreted proteins that have fundamental roles in organ development, normal physiology, and immune responses upon binding to their corresponding receptors. The primary functions of chemokines are to coordinate and recruit immune cells to and from tissues and to participate in regulating interactions between immune cells. In addition to the generally recognized antimicrobial immunity, the chemokine/chemokine receptor axis also exerts a tumorigenic function in many different cancer models and is involved in the formation of immunosuppressive and protective tumor microenvironment (TME), making them potential prognostic markers for various hematologic and solid tumors. In fact, apart from its vital role in tumors, almost all inflammatory diseases involve chemokines and their receptors in one way or another. Modulating the expression of chemokines and/or their corresponding receptors on tumor cells or immune cells provides the basis for the exploitation of new drugs for clinical evaluation in the treatment of related diseases. Here, we summarize recent advances of chemokine systems in protumor and antitumor immune responses and discuss the prevailing understanding of how the chemokine system operates in inflammatory diseases. In this review, we also emphatically highlight the complexity of the chemokine system and explore its potential to guide the treatment of cancer and inflammatory diseases.