Gene delivery of TIPE2 inhibits breast cancer development and metastasis via CD8+ T and NK cell-mediated antitumor responses

MDSC checkpoint blockade therapy: a new breakthrough point overcoming immunosuppression in cancer immunotherapy

Despite the success of cancer immunotherapy in treating hematologic malignancies, their efficacy in solid tumors remains limited due to the immunosuppressive tumor microenvironment (TME), which is mainly formed by myeloid-derived suppressor cells (MDSCs). MDSCs not only exert potent immunosuppressive effects that hinder the success of immune checkpoint inhibitors (ICIs) and adaptive cellular therapies, but they also promote tumor advancement through non-immunological pathways, including promoting angiogenesis, driving epithelial-mesenchymal transition (EMT), and contributing to the establishment of pre-metastatic environments. While targeting MDSCs alone or in combination with conventional therapies has shown limited success, emerging evidence suggests that MDSC checkpoint blockade in combination with other immunotherapies holds great promise in overcoming both immunological and non-immunological barriers. In this review, we discussed the dual roles of MDSCs, with a particular emphasis on their underexplored checkpoints blockade strategies. We discussed the rationale behind combination strategies, their potential advantages in overcoming MDSC-mediated immunosuppression, and the challenges associated with their development. Additionally, we highlight future research directions aimed at optimizing combination immunotherapies to enhance cancer therapeutic effectiveness, particularly in solid tumor therapies where MDSCs are highly prevalent.

Transcription Factor E2F7 Hampers the Killing Effect of NK Cells against Colorectal Cancer Cells via Activating RAD18 Transcription

As a pivotal defensive line against multitudinous malignant tumors, natural killer (NK) cells exist in the tumor microenvironment (TME). RAD18 E3 Ubiquitin Protein Ligase (RAD18) has been reported to foster the malignant progression of multiple cancers, but its effect on NK function has not been mined. Here, the study was designed to mine the mechanism by which RAD18 regulates the killing effect of NK cells on colorectal cancer (CRC) cells. Expression of E2F Transcription Factor 7 (E2F7) and RAD18 in CRC tissues, their correlation, binding sites, and RAD18 enrichment pathway were analyzed by bioinformatics. Expression of E2F7 and RAD18 in cells was assayed by qRT-PCR and western blot. Dual-luciferase assay and chromatin immunoprecipitation (ChIP) assay verified the regulatory relationship between E2F7 and RAD18. CCK-8 assay was utilized to assay cell viability, colony formation assay to detect cell proliferation, lactate dehydrogenase (LDH) test to assay NK cell cytotoxicity, ELISA to assay levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), and immunofluorescence to detect expression of toxic molecules perforin and granzyme B. High expression of RAD18 and E2F7 was found in CRC tissues and cells. Silencing RAD18 could hamper the proliferation of CRC cells, foster viability and cytotoxicity of NK cells, and increase the secretion of GM-CSF, TNF-α, IFN-γ as well as the expression of perforin and granzyme B. Additionally, ChIP and dual-luciferase reporter assay ascertained the binding relationship between RAD18 promoter region and E2F7. E2F7 could activate the transcription of RAD18, and silencing RAD18 reversed the inhibitory effect of E2F7 overexpression on NK cell killing. This work clarified the inhibitory effect of the E2F7/RAD18 axis on NK cell killing in CRC, and proffered a new direction for immunotherapy of CRC in targeted immune microenvironment.

Checkpoint TIPE2 Limits the Helper Functions of NK Cells in Supporting Antitumor CD8+ T Cells

Natural killer (NK) cells not only are innate effector lymphocytes that directly participate in tumor surveillance but are also essential helpers in the antitumor CD8⁺ T-cell response. However, the molecular mechanisms and potential checkpoints regulating NK cell helper functions remain elusive. Here, it is shown that the T-bet/Eomes-IFN-γ axis in NK cells is essential for CD8⁺ T cell-dependent tumor control, whereas T-bet-dependent NK cell effector functions are required for an optimal response to anti-PD-L1 immunotherapy. Importantly, NK cell-expressed TIPE2 (tumor necrosis factor-alpha-induced protein-8 like-2) represents a checkpoint molecule for NK cell helper function, since Tipe2 deletion in NK cells not only enhances NK-intrinsic antitumor activity but also indirectly improves the antitumor CD8⁺ T cell response by promoting T-bet/Eomes-dependent NK cell effector functions. These studies thus reveal TIPE2 as a checkpoint for NK cell helper function, whose targeting might boost the antitumor T cell response in addition to T cell-based immunotherapy.

TIPE2 sensitizes breast cancer cells to paclitaxel by suppressing drug-induced autophagy and cancer stem cell properties

Drug resistance is a great obstacle to the clinical application of paclitaxel (PTX) in breast cancer treatment. Chemoresistance can be either primary or acquired. Multifarious factors are related to drug resistance. Among these factors, drug-induced autophagy has been shown to contribute to acquired chemoresistance in cancer cells. Additionally, cancer stem cells (CSCs) drive primary chemoresistance. Recent advances regarding TIPE2 demonstrate that TIPE2 enhances osteosarcoma and non-small cell lung cancer cell sensitivity to cisplatin. However, the role of TIPE2 in PTX resistance in breast cancer cells has not been elucidated. Here, the in vitro and in vivo study demonstrated that TIPE2 sensitized breast cancer cells to PTX by suppressing drug-induced autophagy and CSC properties. Mechanistically, we found that TIPE2 activated the AKT/mTOR signalling pathway and inhibited the TAK1/MAPK signalling pathway to suppress drug-induced autophagy. Moreover, TIPE2 inhibited TAK1/NF-κB activation to reduce breast CSC properties. Collectively, our results first elucidated the inhibitory role of TIPE2 in breast cancer chemoresistance. Thus, TIPE2 may be a new target for breast cancer chemotherapy.

TIPE2 acts as a tumor suppressor and correlates with tumor microenvironment immunity in epithelial ovarian cancer

BACKGROUND

Epithelial ovarian cancer (EOC) is one of the deadliest gynecologic cancers. The etiology of EOC has still not been elucidated thoroughly. Tumor necrosis factor-α-induced protein 8-like2 (TNFAIP8L2, TIPE2), an important regulator of inflammation and immune homeostasis, plays a critical role in the progression of various cancers. This study aims to investigate the role of TIPE2 in EOC.

METHODS

Expression of TIPE2 protein and mRNA in EOC tissues and cell lines was examined using Western blot and quantitative real-time PCR (qRT-PCR). The functions of TIPE2 in EOC were investigated by cell proliferation assay, colony assay, transwell assay, and apoptosis analysis in vitro. To further investigate the regulatory mechanisms of TIPE2 in EOC, RNA-seq and western blot were performed. Finally, the CIBERSORT algorithm and databases including Tumor Immune Single-cell Hub (TISCH), Tumor Immune Estimation Resource (TIMER), Tumor-Immune System Interaction (TISIDB), and The Gene Expression Profiling Interactive Analysis (GEPIA) were used to elucidate its potential role in regulating tumor immune infiltration in the tumor microenvironment (TME).

RESULTS

TIPE2 expression was shown to be considerably lower in both EOC samples and cell lines. Overexpression of TIPE2 suppressed EOC cell proliferation, colony formation, and motility in vitro. Mechanistically, TIPE2 suppressed EOC by blocking the PI3K/Akt signaling pathway, according to bioinformatics analysis and western blot in TIPE2 overexpression EOC cell lines, and the anti-oncogenic potentials of TIPE2 in EOC cells could be partially abrogated by the PI3K agonist, 740Y-P. Finally, TIPE2 expression was positively associated with various immune cells and possibly involved in the regulation of macrophage polarization in ovarian cancer.

CONCLUSIONS

We detail the regulatory mechanism of TIPE2 in EOC carcinogenesis, as well as how it correlates with immune infiltration, emphasizing its potential as a therapeutic target in ovarian cancer.

The crosstalk between the gut microbiota and tumor immunity: Implications for cancer progression and treatment outcomes

The gastrointestinal tract is inhabited by trillions of commensal microorganisms that constitute the gut microbiota. As a main metabolic organ, the gut microbiota has co-evolved in a symbiotic relationship with its host, contributing to physiological homeostasis. Recent advances have provided mechanistic insights into the dual role of the gut microbiota in cancer pathogenesis. Particularly, compelling evidence indicates that the gut microbiota exerts regulatory effects on the host immune system to fight against cancer development. Some microbiota-derived metabolites have been suggested as potential activators of antitumor immunity. On the contrary, the disequilibrium of intestinal microbial communities, a condition termed dysbiosis, can induce cancer development. The altered gut microbiota reprograms the hostile tumor microenvironment (TME), thus allowing cancer cells to avoid immunosurvelliance. Furthermore, the gut microbiota has been associated with the effects and complications of cancer therapy given its prominent immunoregulatory properties. Therapeutic measures that aim to manipulate the interplay between the gut microbiota and tumor immunity may bring new breakthroughs in cancer treatment. Herein, we provide a comprehensive update on the evidence for the implication of the gut microbiota in immune-oncology and discuss the fundamental mechanisms underlying the influence of intestinal microbial communities on systemic cancer therapy, in order to provide important clues toward improving treatment outcomes in cancer patients.

Comprehensive analysis of tumor necrosis factor-α-inducible protein 8-like 2 (TIPE2): A potential novel pan-cancer immune checkpoint

Tumor necrosis factor-α-inducible protein 8-like 2 (TIPE2) is encoded by TNFAIP8L2 and is a newly identified negative regulator of natural and acquired immunity that plays a critical function in maintaining immune homeostasis. Recently, CAR-NK immune cell therapy has been a focus of major research efforts as a novel cancer therapeutic strategy. TIPE2 is a potential checkpoint molecule for immune cell maturation and antitumor immunity that could be used as a novel NK cell-based immunotherapeutic approach. In this study, we explored the expression of TNFAIP8L2 across various tumor types and found that TNFAIP8L2 was highly expressed in most tumor types and correlated with prognosis. Survival analysis showed that TNFAIP8L2 expression was predictive of improved survival in cervical-squamous-cell-carcinoma (CESC), sarcoma (SARC) and skin-cutaneous-melanoma (SKCM). Conversely, TNFAIP8L2 expression predicted poorer survival in acute myeloid leukemia (LAML), lower-grade-glioma (LGG), kidney-renal-clear-cell-carcinoma (KIRC) and uveal-melanoma (UVM). Analysis of stemness features and immune cell infiltration indicated that TNFAIP8L2 was significantly associated with cancer stem cell index and increased macrophage and dendritic cell infiltration. Our data suggest that TNFAIP8L2 may be a novel immune checkpoint biomarker across different tumor types, particularly in LAML, LGG, KIRC and UVM, and may have further utility as a potential target for immunotherapy.

Gene therapy: A promising approach for breast cancer treatment

Breast cancer (BC) is the most prevalent malignancy and the second leading cause of death among women worldwide that is caused by numerous genetic and environmental factors. Hence, effective treatment for this type of cancer requires new therapeutic approaches. The traditional methods for treating this cancer have side effects, therefore so much research have been performed in last decade to find new methods to alleviate these problems. The study of the molecular basis of breast cancer has led to the introduction of gene therapy as an effective therapeutic approach for this cancer. Gene therapy involves sending genetic material through a vector into target cells, which is followed by a correction, addition, or suppression of the gene. In this technique, it is necessary to target tumour cells without affecting normal cells. In addition, clinical trial studies have shown that this approach is less toxic than traditional therapies. This study will review various aspects of breast cancer, gene therapy strategies, limitations, challenges and recent studies in this area.

Modulation of the tumor microenvironment (TME) by melatonin

The tumor microenvironment (TME) includes a number of non-cancerous cells that affect cancer cell survival. Although CD8+ T lymphocytes and natural killer (NK) cells suppress tumor growth through induction of cell death in cancer cells, there are various immunosuppressive cells such as regulatory T cells (Tregs), tumor-associated macrophages (TAMs), cancer-associated fibroblasts (CAFs), myeloid-derived suppressor cells (MDSCs), etc., which drive cancer cell proliferation. These cells may also support tumor growth and metastasis by stimulating angiogenesis, epithelial-mesenchymal transition (EMT), and resistance to apoptosis. Interactions between cancer cells and other cells, as well as molecules released into EMT, play a key role in tumor growth and suppression of antitumoral immunity. Melatonin is a natural hormone that may be found in certain foods and is also available as a drug. Melatonin has been demonstrated to modulate cell activity and the release of cytokines and growth factors in TME. The purpose of this review is to explain the cellular and molecular mechanisms of cancer cell resistance as a result of interactions with TME. Next, we explain how melatonin affects cells and interactions within the TME.

Immunomodulation: An immune regulatory mechanism in carcinoma therapeutics

Cancer has been generally related to the possession of numerous mutations which interrupt important signaling pathways. Nevertheless, deregulated immunological signaling is considered as one of the key factors associated with the development and progression of cancer. The signaling pathways operate as modular network with different components interacting in a switch-like fashion with two proteins interplaying between each other leading to direct or indirect inhibition or stimulation of down-stream factors. Genetic, epigenetic, and transcriptomic alterations maintain the pathological conduit of different signaling pathways via affecting diverse mechanisms including cell destiny. At present, immunotherapy is one of the best therapies opted for cancer treatment. The cancer immunotherapy strategy includes harnessing the specificity and killing mechanisms of the immunological system to target and eradicate malignant cells. Targeted therapies utilizing several little molecules including Galunisertib, Astragaloside-IV, Melatonin, and Jervine capable of regulating key signaling pathways can effectively help in the management of different carcinomas.

TIPE2 Suppresses Malignancy of Pancreatic Cancer Through Inhibiting TGFβ1 Mediated Signaling Pathway

Pancreatic cancer is one of the major reasons of cancer-associated deaths due to poor diagnosis, high metastasis and drug resistance. Therefore, it is important to understand the cellular and molecular mechanisms of pancreatic cancer to identify new targets for the treatment. TIPE2 is an essential regulator of tumor apoptosis, inflammation and immune homeostasis. However, the role of TIPE2 is still not fully understood in pancreatic cancer. In this study, we found the expression of TIPE2 was decreased in pancreatic cancer tissues compare to paracancerous tissues, which was negatively correlated with tumor size in patients. Overexpression of TIPE2 significantly decreased cell proliferation, metastasis and increased apoptotic events in pancreatic cancer cell lines. Moreover, the results obtained from real time PCR and western blot revealed that TIPE2 was also involved in inhibiting MMPs and N-Cadherin expression while increasing Bax expression in pancreatic cancer cells. Similarly, TIPE2 could inhibit tumor growth in vivo, decrease the expression of Ki-67 and N-Cadherin, and increase the expression of Bax by IHC analysis in tumor tissues isolated from tumor-bearing mice. Mechanistic studies exhibited that TIPE2 might suppress pancreatic cancer development through inhibiting PI3K/AKT and Raf/MEK/ERK signaling pathways triggered by TGFβ1. Moreover, the tumor-infiltrating lymphocytes from tumor-bearing mice were analyzed by flow cytometry, and showed that TIPE2 could promote T cell activation to exert an anti-tumor effect possibly through activation of DCs in a TGFβ1 dependent manner. In general, we described the multiple regulatory mechanisms of TIPE2 in pancreatic tumorigenesis and tumor microenvironment, which suggested TIPE2 may act as a potential therapeutic target in pancreatic cancer.

Tumor Necrosis Factor-α-Induced Protein 8-Like 2 Negatively Regulates Innate Immunity Against RNA Virus by Targeting RIG-I in Macrophages

A systematic and flexible immunoregulatory network is required to ensure the proper outcome of antiviral immune signaling and maintain homeostasis during viral infection. Tumor necrosis factor-α-induced protein 8-like 2 (TIPE2), a novel immunoregulatory protein, has been extensively studied in inflammatory response, apoptosis, and cancer. However, the function of TIPE2 in antiviral innate immunity is poorly clarified. In this study, we reported that the expression of TIPE2 declined at the early period and then climbed up in macrophages under RNA virus stimulation. Knockout of TIPE2 in the macrophages enhanced the antiviral capacity and facilitated type I interferon (IFN) signaling after RNA viral infection both in vitro and in vivo. Consistently, overexpression of TIPE2 inhibited the production of type I IFNs and pro-inflammatory cytokines, and thus promoted the viral infection. Moreover, TIPE2 restrained the activation of TBK1 and IRF3 in the retinoic acid inducible gene-I (RIG-I)-like receptors (RLR) signaling pathway by directly interacting with retinoic acid inducible gene-I (RIG-I). Taken together, our results suggested that TIPE2 suppresses the type I IFN response induced by RNA virus by targeting RIG-I and blocking the activation of downstream signaling. These findings will provide new insights to reveal the immunological function of TIPE2 and may help to develop new strategies for the clinical treatment of RNA viral infections.

The expression and clinical significance of signal transducer and activator of transcription 3, tumor necrosis factor α induced protein 8-like 2, and runt-related transcription factor 1 in breast cancer patients

BACKGROUND

This study explored the expression and clinical significance of signal transducer and activator of transcription 3 (STAT3), tumor necrosis factor α induced protein 8-like 2 (TIPE2), and runt-related transcription factor 1 (RUNX1) in breast cancer tissue.

METHODS

From October 2014 to October 2017, 68 breast cancer patients (68 breast cancer tissue specimens) who underwent a radical mastectomy in our hospital were set as the observation group and the corresponding normal tissue 3 cm away from the cancer tissue was selected as the control group. The expression levels of STAT3, TIPE2, and RUNX1 in the two groups were compared via immunohistochemical staining. Multiple logistic regression was then used to analyze the related risk factors affecting the 2-year prognosis of breast cancer patients. The receiver operating characteristic (ROC) curve was then plotted and the area under the ROC curve was calculated. The predictive values of STAT3, TIPE2, and RUNX1, and the predictive value of the three transcription factors combined on the 2-year prognostic survival of breast cancer patients were determined.

RESULTS

(I) In the observation group, the positive expression of STAT3 and the negative expression of TIPE2 and RUNX1 were significantly higher than those in the control group (P<0.05). (II) Of the 68 patients, 51 survived within 2 years and 17 patients died. Positive STAT3 expression, negative TIPE2 expression, negative RUNX1 expression, poor histological differentiation, TNM stage III-IV, and distant metastasis were all identified as factors that can affect the 2-year prognosis of breast cancer patients (P<0.05). (III) The ROC curve analysis examining the 2-year prognostic survival of breast cancer patients showed that the area under the curve achieved the largest value when the predictive values of STAT3, TIPE2, RUNX1 were combined.

CONCLUSIONS

The levels of STAT3, TIPE2, and RUNX1 expression in breast cancer tissues were significantly different from that in adjacent normal tissues. This suggested that the combined detection of STAT3, TIPE2, and RUNX1 may improve the rate of early breast cancer diagnosis. Furthermore, STAT3, TIPE2, and RUNX1 may be useful in evaluating the prognosis of the patients with breast cancer.

Bioluminescence Imaging Applications in Cancer: A Comprehensive Review

Bioluminescence imaging (BLI), an optical preclinical imaging modality, is an invaluable imaging modality due to its low-cost, high throughput, fast acquisition times, and functional imaging capabilities. BLI is being extensively used in the field of cancer imaging, especially with the recent developments in genetic-engineering, stem cell, and gene therapy treatments. The purpose of this paper is to provide a comprehensive review of the principles, developments, and current status of BLI in cancer research. This paper covers the fundamental BLI concepts including BLI reporters and enzyme-substrate systems, data acquisition, and image characteristics. It reviews the studies discussing the use of BLI in cancer research such as imaging tumor-characteristic phenomena including tumorigenesis, metastasis, cancer metabolism, apoptosis, hypoxia, and angiogenesis, and response to cancer therapy treatments including chemotherapy, radiotherapy, immunotherapy, gene therapy, and stem cell therapy. The key advantages and disadvantages of BLI compared to other common imaging modalities are also discussed.

Regulatory Roles of Tumor Necrosis Factor-α-Induced Protein 8 Like-Protein 2 in Inflammation, Immunity and Cancers: A Review

Tumor necrosis factor-alpha (TNF-α)-induced protein 8 (TNFAIP8/TIPE) family, including TNFAIP8 (TIPE), TNFAIP8 like-protein 1 (TNFAIP8L1/TIPE1), TNFAIP8 like-protein 2 (TNFAIP8L2/TIPE2), and TNFAIP8 like-protein 3 (TNFAIP8L3/TIPE3), plays a vital role in regulating inflammatory responses, immune homeostasis, and cancer development. Over the last decade, studies have shown that TIPE2 protein is differentially expressed in diverse cells and tissues. The dysregulation of TIPE2 protein can lead to dysregulation of inflammatory responses and immune homeostasis, and change the basic characteristics of cancers. In consideration of the immeasurable values of TIPE2 in diagnosis, treatment, and prognosis of various human diseases, this review will focus on the expression pattern, structure, and regulatory roles of TIPE2 in inflammation, immunity, and cancers.

Improving therapeutic potential of non-viral minimized DNA vectors

The tragic deaths of three patients in a recent AAV-based X-linked myotubular myopathy clinical trial highlight once again the pressing need for safe and reliable gene delivery vectors. Non-viral minimized DNA vectors offer one possible way to meet this need. Recent pre-clinical results with minimized DNA vectors have yielded promising outcomes in cancer therapy, stem cell therapy, stem cell reprograming, and other uses. Broad clinical use of these vectors, however, remains to be realized. Further advances in vector design and production are ongoing. An intriguing and promising potential development results from manipulation of the specific shape of non-viral minimized DNA vectors. By improving cellular uptake and biodistribution specificity, this approach could impact gene therapy, DNA nanotechnology, and personalized medicine.

Natural killer and NKT cells in the male reproductive tract

Natural killer (NK) cells are important effector lymphocytes that play a pivotal role in the innate and adaptive immune responses to tumors and viral infection. NKT cells are a heterogeneous group of T cells that share properties with both T cells and NK cells. They display immunoregulatory properties as they facilitate the cell-mediated immune response to tumors and infectious diseases, and inhibit cell-mediated immunity associated with autoimmune diseases and allograft rejection. However, the roles of NK and NKT cells in the male reproductive tract remain largely unexplored, in particular, NKT cells, tissue distribution, and state of health or disease. Infection and inflammation of the male genital tract are thought to be the primary etiological factors of male infertility. In this review, we considered this complex and rapidly growing field. We summarize the recent findings and the characterization and roles of NK and NKT cells in the male reproductive tract, including the testis, epididymis, prostate, seminal vesicle, and semen, to enhance our understanding of the immunological mechanisms of male infertility and for the design effective vaccines for male reproductive health in the future.

Immune Negative Regulator TIPE2 Inhibits Cervical Squamous Cancer Progression Through Erk1/2 Signaling

Tumor necrosis factor (TNF)-α-induced protein-8-like 2, or TIPE2, is a newly found immune negative regulatory molecule. This study further investigated the role of TIPE2 on proliferation and invasion of cervical squamous cancer cells. Expression of TIPE2 was compared in cervical squamous cancer tissues and adjacent normal tissues by Western blot and immunohistochemistry (IHC). Cervical squamous cancer cell lines, SiHa and C33A, were transfected with recombinant plasmid encoding TIPE2 and tested for cytologic characteristics. The impact of TIPE2 on phosphorylation of extracellular signal-regulated kinase (Erk) signaling pathway was also tested by Western blot analysis of key factors. TIPE2 expression was higher in cervical cancer tissues than that in normal tissue. IHC score of tumor tissue was negatively associated with lymphatic metastasis. Over expression of TIPE2 effectively inhibited the proliferation of cervical cancer cells. Wound healing and transwell assay showed that over expression of TIPE2 suppressed cell migration and invasion in vitro. Meanwhile, phosphorylation of Erk1/2 and upstream mitogen-activated protein kinase kinase (MEK) 1/2 was reduced by TIPE2. TIPE2 is negatively related with development of cervical squamous cancer. TIPE2 is an inhibitory factor of proliferation and invasion of cervical squamous cancer cells, probably through inhibiting Erk signaling pathway.

TIPE2 Induced the Proliferation, Survival, and Migration of Lung Cancer Cells Through Modulation of Akt/mTOR/NF-κB Signaling Cascade

Lung cancer represents the most common cause of cancer deaths in the world, constituting around 11.6% of all new cancer cases and 18.4% of cancer-related deaths. The propensity for early spread, lack of suitable biomarkers for early diagnosis, as well as prognosis and ineffective existing therapies, contribute to the poor survival rate of lung cancer. Therefore, there is an urgent need to develop novel biomarkers for early diagnosis and prognosis which in turn can facilitate newer therapeutic avenues for the management of this aggressive neoplasm. TIPE2 (tumor necrosis factor-α-induced protein 8-like 2), a recently identified cytoplasmic protein, possesses enormous potential in this regard. Immunohistochemical analysis showed that TIPE2 was significantly upregulated in different stages and grades of lung cancer tissues compared to normal lung tissues, implying its involvement in the positive regulation of lung cancer. Further, knockout of TIPE2 resulted in significantly reduced proliferation, survival, and migration of human lung cancer cells through modulation of the Akt/mTOR/NF-κB signaling axis. In addition, knockout of TIPE2 also caused arrest in the S phase of the cell cycle of lung cancer cells. As tobacco is the most predominant risk factor for lung cancer, we therefore evaluated the effect of TIPE2 in tobacco-mediated lung carcinogenesis as well. Our results showed that TIPE2 was involved in nicotine-, nicotine-derived nitrosamine ketone (NNK)-, N-nitrosonornicotine (NNN)-, and benzo[a]pyrene (BaP)-mediated lung cancer through inhibited proliferation, survival, and migration via modulation of nuclear factor kappa B (NF-κB)- and NF-κB-regulated gene products, which are involved in the regulation of diverse processes in lung cancer cells. Taken together, TIPE2 possesses an important role in the development and progression of lung cancer, particularly in tobacco-promoted lung cancer, and hence, specific targeting of it holds an enormous prospect in newer therapeutic interventions in lung cancer. However, these findings need to be validated in the in vivo and clinical settings to fully establish the diagnostic and prognostic importance of TIPE2 against lung cancer.

Boosting immune system against cancer by melatonin: A mechanistic viewpoint

Cancer is a disease of high complexity. Resistance to therapy is a major challenge in cancer targeted therapies. Overcoming this resistance requires a deep knowledge of the cellular interactions within tumor. Natural killer (NK) cells and cytotoxic T lymphocytes (CTLs) are the main anti-cancer immune cells, while T regulatory cells (Tregs) and cancer associated fibroblasts (CAFs) facilitate immune escape of cancer cells. Melatonin is a natural agent with anti-cancer functions that has also been suggested as an adjuvant in combination with cancer therapy modalities such as chemotherapy, radiotherapy, immunotherapy and tumor vaccination. One of the main effects of melatonin is regulation of immune responses against cancer cells. Melatonin has been shown to potentiate the activities of anti-cancer immune cells, as well as attenuating the activities of Tregs and CAFs. It also has a potent effect on the mitochondria, which may change immune responses against cancer. In this review, we explain the mechanisms of immune regulation by melatonin involved in its anti-cancer effects.

Recruitment of stromal cells into tumour microenvironment promote the metastatic spread of breast cancer

Currently, metastasis remains the primary cause of death of patients with breast cancer despite the important advances in the treatment of this disease. In the complex tumour microenvironment network, several malignant and non-malignant cell types as well as components of extracellular matrix cooperate in promoting the metastatic spread of breast carcinoma. Many components of the stromal compartment are recruited from distant sites to the tumour including mesenchymal stem cells, endothelial cells, macrophages and other immune cells whereas other cells such as fibroblasts are already present in both primary and secondary lesions. When these cells come into contact with cancer cells they are "educated" and acquire a pro-tumoural phenotype, which support all the steps of the metastatic cascade. In this Review, we highlight the role played by each stromal component in guiding cancer cells in their venture towards colonizing metastatic sites.

TIPE2 as a potential therapeutic target in chronic viral hepatitis

Tumor necrosis factor-α-induced protein-8 like-2 (TIPE2) is a novel negative regulator of innate and adaptive immune responses by binding to caspase-8. The binding of TIPE2 and caspase-8 can inhibit the activity of activating protein-1(AP-1) and nuclear factor-κB (NF-κB), ultimately promoting Fas-induced apoptosis in immune cells. Therefore, TIPE2-caspase-8-NF-κB signaling might serve as a biomarker and a potential target for therapeutic intervention. Areas covered: This review summarizes the biological functions of TIPE2 in the regulation of immune homeostasis and the underlying mechanism by which TIPE2 is regulated in the human immune response. The molecular pathway of TIPE2-caspase-8 signaling in chronic infections of hepatitis B virus and hepatitis C virus is also explained. Expert opinion: Considering the essential role of TIPE2 in linking immunity and inflammation, this protein may be a promising therapeutic target in chronic viral hepatitis. However, studies are necessary to elucidate the molecular mechanism of TIPE2 in the immunogenesis of viral hepatitis and to develop potential interventions for breaking immune tolerance in chronic hepatitis B virus infection. Additional studies are required to understand how TIPE2 binds to caspase-8.

Targeting the Interplay between Epithelial-to-Mesenchymal-Transition and the Immune System for Effective Immunotherapy

Over the last decade, both early diagnosis and targeted therapy have improved the survival rates of many cancer patients. Most recently, immunotherapy has revolutionized the treatment options for cancers such as melanoma. Unfortunately, a significant portion of cancers (including lung and breast cancers) do not respond to immunotherapy, and many of them develop resistance to chemotherapy. Molecular characterization of non-responsive cancers suggest that an embryonic program known as epithelial-mesenchymal transition (EMT), which is mostly latent in adults, can be activated under selective pressures, rendering these cancers resistant to chemo- and immunotherapies. EMT can also drive tumor metastases, which in turn also suppress the cancer-fighting activity of cytotoxic T cells that traffic into the tumor, causing immunotherapy to fail. In this review, we compare and contrast immunotherapy treatment options of non-small cell lung cancer (NSCLC) and triple negative breast cancer (TNBC). We discuss why, despite breakthrough progress in immunotherapy, attaining predictable outcomes in the clinic is mostly an unsolved problem for these tumors. Although these two cancer types appear different based upon their tissues of origin and molecular classification, gene expression indicate that they possess many similarities. Patient tumors exhibit activation of EMT, and resulting stem cell properties in both these cancer types associate with metastasis and resistance to existing cancer therapies. In addition, the EMT transition in both these cancers plays a crucial role in immunosuppression, which exacerbates treatment resistance. To improve cancer-related survival we need to understand and circumvent, the mechanisms through which these tumors become therapy resistant. In this review, we discuss new information and complementary perspectives to inform combination treatment strategies to expand and improve the anti-tumor responses of currently available clinical immune checkpoint inhibitors.

RNA-Seq transcriptome analysis shows anti-tumor actions of melatonin in a breast cancer xenograft model

Melatonin is a pleiotropic anti-cancer molecule that controls cancer growth by multiple mechanisms. RNA-Seq can potentially evaluate therapeutic response and its use in xenograft tumor models can differentiate the changes that occur specifically in tumor cells or in the tumor microenvironment (TME). Melatonin actions were evaluated in a xenograft model of triple-negative breast cancer. Balb/c nude mice bearing MDA-MB-231 tumors were treated with melatonin or vehicle. RNA-Seq was performed on the Illumina HiSeq. 2500 and data were mapped against human and mouse genomes separately to differentiate species-specific expression. Differentially expressed (DE) genes were identified and Weighted Gene Co-expression Network Analysis (WGCNA) was used to detect clusters of highly co-expressed genes. Melatonin treatment reduced tumor growth (p < 0.01). 57 DE genes were identified in murine cells, which represented the TME, and were mainly involved in immune response. The WGCNA detected co-expressed genes in tumor cells and TME, which were related to the immune system among other biological processes. The upregulation of two genes (Tnfaip8l2 and Il1f6) by melatonin was validated in the TME, these genes play important roles in the immune system. Taken together, the transcriptomic data suggests that melatonin anti-tumor actions occur through modulation of TME in this xenograft tumor model.

Tumour necrosis factor-α-induced protein 8-like 2 is a novel regulator of proliferation, migration, and invasion in human rectal adenocarcinoma cells

Tumour necrosis factor‐α‐induced protein 8‐like 2 (TIPE2) is a tumour suppressor in many types of cancer. However, the mechanism of action of TIPE2 on the growth of rectal adenocarcinoma is unknown. Our results showed that the expression levels of TIPE2 in human rectal adenocarcinoma tissues were higher than those in adjacent non‐tumour tissues. Overexpression of TIPE2 reduced the proliferation, migration, and invasion of human rectal adenocarcinoma cells and down‐regulation of TIPE2 showed reverse effects. TIPE2 overexpression increased apoptosis through down‐regulating the expression levels of Wnt3a, phospho (p)‐β‐Catenin, and p‐glycogen synthase kinase‐3β in rectal adenocarcinoma cells, however, TIPE2 knockdown exhibited reverse trends. TIPE2 overexpression decreased autophagy by reducing the expression levels of p‐Smad2, p‐Smad3, and transforming growth factor‐beta (TGF‐β) in rectal adenocarcinoma cells, however, TIPE2 knockdown showed opposite effects. Furthermore, TIPE2 overexpression reduced the growth of xenografted human rectal adenocarcinoma, whereas TIPE2 knockdown promoted the growth of rectal adenocarcinoma tumours by modulating angiogenesis. In conclusion, TIPE2 could regulate the proliferation, migration, and invasion of human rectal adenocarcinoma cells through Wnt/β‐Catenin and TGF‐β/Smad2/3 signalling pathways. TIPE2 is a potential therapeutic target for the treatment of rectal adenocarcinoma.

Knockdown of TIPE2 increases the proliferation in lipopolysaccharide-stimulated gastric cancer cells

Background

Gastric cancer (GC) is one of the most common malignant diseases with high morbidity and mortality, especially in Asian countries. During the GC developing progress, TIPE2, a member of TNF-alpha induced protein 8-like (TNFAIP8L) family, may play important roles. However, the molecular mechanisms of TIPE2 contributing to cell proliferation and tumor growth are poorly understood in GC. We performed flow cytometry to detect the cell cycle of TIPE2-knockdown GC cells under lipopolysaccharide (LPS) stimulation.

Methods

We measured TIPE2 expression in tumor samples from 46 human GC patients at mRNA level by Realtime PCR and in 68 pairs of GC tissues at protein level by immunohistochemistry. We established stable TIPE2 knockdown SGC7901 and BGC823 cell lines and performed CCK-8 and EdU proliferation assays under the stimulation of LPS. And then we analyzed AKT, IκBα and ERK phosphorylation levels, as well as cycle related proteins CDK4 and CyclinD3 in the stable TIPE2 knockdown SGC7901 and BGC823 cells.

Results

Our present studies indicated that the expression of TIPE2 was significantly decreased in tumor tissues compared to distant mucosa tissues in human GC patients. TIPE2 inhibited proliferation stimulated by LPS in SGC7901 and BGC823 cells. Silencing of TIPE2 significantly decreased cell G₀/G₁ phase ratio and increased G₂/M phase. TIPE2 knockdown SGC7901 and BGC823 cells declined AKT and IκBα phosphorylation. TIPE2’s action on GC cell cycle was.

Conclusions

Our results demonstrated that TIPE2 is a novel tumor suppressor gene that inhibits GC growth may mediated via AKT and IκBα phosphorylated activation. We revealed that TIPE2 may effectively interdict neoplasm development, which has potential clinical application values for GC targeted therapies.

TIPE2 inhibits GC via regulation of cell proliferation, apoptosis and inflammation

Gastric cancer (GC), a type of gastric mucosal epithelium disease caused by common malignant tumors, has become a major threat to human health and survival. Tumor necrosis factor-α-induced protein-8 like-2 (TIPE2) is a negative immune regulatory factor that is selectively expressed in immune organs, immune cells and various epithelial cells and serves an important role in the maintenance of human physiological immune homeostasis. In our preliminary study, we found that the expression of TIPE2 was downregulated or absent in GC tissues compared with normal gastric mucosa tissues, indicating that TIPE2 may play a significant role in the development of GC. To clarify the role of TIPE2 in the progression of human GC and to elucidate the underlying mechanism, the association between TIPE2 and phosphatidylinositol 3-kinase (PI3K)/AKT, the cell cycle, the caspase-related apoptosis pathway and the NF-κB signaling pathway were investigated through western blot and flow cytometric analysis. It was determined that TIPE2 inhibited GC cell proliferation mainly by reducing the expression of phosphorylated AKT and ERK, which caused subsequent inhibition of the PI3K-AKT and Ras-Raf-MEK-ERK1/2 signaling pathways. Additionally, we investigated the relationship between TIPE2 and GC and discovered that TIPE2 inhibited tumor progression via growth, apoptosis and inflammatory pathways. The results of the present study provided a theoretical basis for the development and application of TIPE2 as an antitumor agent.

H2S Donor NaHS Changes the Production of Endogenous H2S and NO in D-Galactose-Induced Accelerated Ageing

Aims. The study was designed to explore whether hydrogen sulphide (H₂S) and nitric oxide (NO) generation changed in D-galactose- (D-gal-) induced ageing, the possible effects of exogenous H₂S supplementation, and related mechanisms. Results. In D-gal-induced senescent mice, both H₂S and NO levels in the heart, liver, and kidney tissues were decreased significantly. A similar trend was observed in D-gal-challenged human umbilical vein endothelial cells (HUVECs). Sustained H₂S donor (NaHS) treatment for 2 months elevated H₂S and NO levels in these mice, and during this period, the D-gal-induced senescent phenotype was reversed. The protective effect of NaHS is associated with a decrease in reactive oxygen species levels and an increase in antioxidants, such as glutathione, and superoxide dismutase and glutathione peroxidase activities. Increased expression of the H₂S-producing enzymes cystathionine γ-lyase (CSE) and cystathionine-β-synthase (CBS) in the heart, liver, and kidney tissues was observed in the NaHS-treated groups. NaHS supplementation also significantly postponed D-gal-induced HUVEC senescence. Conclusions. Endogenous hydrogen sulphide production in both ageing mice and endothelial cells is insufficient. Exogenous H₂S can partially rescue ageing-related dysfunction by inducing endogenous H₂S and NO production and reducing oxidative stress. Restoring endogenous H₂S production may contribute to healthy ageing, and H₂S may have antiageing effects.