Transforming Growth Factor-β and Axl Induce CXCL5 and Neutrophil Recruitment in Hepatocellular Carcinoma

CXCL5 expression is associated with active signals of macrophages in the microenvironment of papillary thyroid carcinoma

BACKGROUND

C-X-C motif chemokine ligand 5 (CXCL5) is a chemokine molecule that is secreted by immune cells in attracting granulocytes. Studies showed that CXCL5 was related to the progression of papillary thyroid carcinoma (PTC) tumor cells. However, the in vivo effects of CXCL5 on PTC tumor cells and their microenvironment have not been elucidated. The present study aimed to investigate the biological effects of CXCL5 on tumor cells, microenvironment, and clinical progression of PTC.

MATERIALS AND METHODS

The PTC patients from The Human Cancer Genome Atlas (TCGA) - thyroid carcinoma (THCA) were retrieved. There were a total of 500 patients who met the criteria of our study. Differential expression (DEA) and pathway analyses were used to explore the biological effects of CXCL5 gene expression.

RESULTS

In DEA, we found that CXCL5 was mostly associated with PBPP, SLC11A1, and MRC1 (adjusted p<0.001). Samples with CXCL5 FPKM≥1 were related to a different immune profile (p<0.001). In pathway analyses, samples with higher CXCL5 expression possessed higher activities of RAS-RAF, NF-kB, PRC2, IL2, IL5, and Wnt pathways (adjusted p<0.001). In microenvironment analysis, CXCL5 was highly correlated with the activity of macrophage (Rho=0.76; adjusted p<0.001). Clinically, high level of CXCL5 expression was an indicator of tumor stages (p<0.001), nodal metastasis (AUC=0.68), and prognosis (p=0.001).

CONCLUSION

CXCL5 was a significant biomarker of PTC. CXCL5 was highly associated with tumor immunology and microenvironment. Samples with higher CXCL5 expression had more advanced disease status and worse prognosis. CXCL5 target therapy is potentially helpful in advanced PTC.

Signaling molecules in the microenvironment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major fatal cancer that is known for its high recurrence and metastasis. An increasing number of studies have shown that the tumor microenvironment is closely related to the metastasis and invasion of HCC. The HCC microenvironment is a complex integrated system composed of cellular components, the extracellular matrix (ECM), and signaling molecules such as chemokines, growth factors, and cytokines, which are generally regarded as crucial molecules that regulate a series of important processes, such as the migration and invasion of HCC cells. Considering the crucial role of signaling molecules, this review aims to elucidate the regulatory effects of chemokines, growth factors, and cytokines on HCC cells in their microenvironment to provide important references for clarifying the development of HCC and exploring effective therapeutic targets.

The Role of Adipocytes Recruited as Part of Tumor Microenvironment in Promoting Colorectal Cancer Metastases

Adipose tissue dysfunction, which is associated with an increased risk of colorectal cancer (CRC), is a significant factor in the pathophysiology of obesity. Obesity-related inflammation and extracellular matrix (ECM) remodeling promote colorectal cancer metastasis (CRCM) by shaping the tumor microenvironment (TME). When CRC occurs, the metabolic symbiosis of tumor cells recruits adjacent adipocytes into the TME to supply energy. Meanwhile, abundant immune cells, from adipose tissue and blood, are recruited into the TME, which is stimulated by pro-inflammatory factors and triggers a chronic local pro-inflammatory TME. Dysregulated ECM proteins and cell surface adhesion molecules enhance ECM remodeling and further increase contractibility between tumor and stromal cells, which promotes epithelial-mesenchymal transition (EMT). EMT increases tumor migration and invasion into surrounding tissues or vessels and accelerates CRCM. Colorectal symbiotic microbiota also plays an important role in the promotion of CRCM. In this review, we provide adipose tissue and its contributions to CRC, with a special emphasis on the role of adipocytes, macrophages, neutrophils, T cells, ECM, and symbiotic gut microbiota in the progression of CRC and their contributions to the CRC microenvironment. We highlight the interactions between adipocytes and tumor cells, and potential therapeutic approaches to target these interactions.

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.

MFAP2 induces epithelial-mesenchymal transformation of osteosarcoma cells by activating the Notch1 pathway

Background

Osteosarcoma (OS) is a malignancy originating from mesenchymal tissue. Microfibril-associated protein 2 (MFAP2) plays a crucial role in cancer, notably promoting epithelial-mesenchymal transition (EMT). However, its involvement in OS remains unexplored.

Methods

MFAP2 was silenced in U2OS cells using shRNA targeting MFAP2 (sh-MFAP2) and validated by quantitative real-time polymerase chain reaction (qRT-PCR). We extracted gene chip data of MFAP2 from multiple databases (GSE28424, GSE42572, and GSE126209). Correlation analyses between MFAP2 and the Notch1 pathway identified through the gene set variation analysis (GSVA) enrichment analysis were conducted using the Pearson correlation method. Cellular behaviors (viability, migration, and invasion) were assessed via the Cell Counting Kit-8 (CCK-8), wound healing, and Transwell assays. EMT markers (N-cadherin, vimentin, and β-catenin) and Notch1 levels were examined by western blotting and qRT-PCR. Cell morphology was observed microscopically to evaluate EMT. Finally, the role of MFAP2 in OS was validated through a xenograft tumor model.

Results

OS cell lines exhibited higher MFAP2 mRNA expression than normal osteoblasts. MFAP2 knockdown in U2OS cells significantly reduced viability, migration, and invasion, along with downregulation of N-cadherin and vimentin, as well as upregulation of β-catenin. MFAP2 significantly correlated with the Notch1 pathway in OS and its knockdown inhibited Notch1 protein expression. Furthermore, Notch1 activation reversed the inhibitory effects of MFAP2 knockdown on the malignant characteristic of U2OS cells. Additionally, MFAP2 knockdown inhibited tumor growth, expression levels of EMT markers, and Notch1 expression in OS tumor tissues.

Conclusions

Our study revealed that MFAP2 was an upstream regulator of the Notch1 signaling pathway to promote EMT in OS. These findings suggested MFAP2 as a potential OS therapy target.

Heterogeneity of myeloid cells in common cancers: Single cell insights and targeting strategies

Tumor microenvironment (TME), is characterized by a complex and heterogenous composition involving a substantial population of immune cells. Myeloid cells comprising over half of the solid tumor mass, are undoubtedly one of the most prominent cell populations associated with tumors. Studies have unambiguously established that myeloid cells play a key role in tumor development, including immune suppression, pro-inflammation, promote tumor metastasis and angiogenesis, for example, tumor-associated macrophages promote tumor progression in a variety of common tumors, including lung cancer, through direct or indirect interactions with the TME. However, due to previous technological constraints, research on myeloid cells often tended to be conducted as studies with low throughput and limited resolution. For example, the conventional categorization of macrophages into M1-like and M2-like subsets based solely on their anti-tumor and pro-tumor roles has disregarded their continuum of states, resulting in an inadequate analysis of the high heterogeneity characterizing myeloid cells. The widespread adoption of single-cell RNA sequencing (scRNA-seq) in tumor immunology has propelled researchers into a new realm of understanding, leading to the establishment of novel subsets and targets. In this review, the origin of myeloid cells in high-incidence cancers, the functions of myeloid cell subsets examined through traditional and single-cell perspectives, as well as specific targeting strategies, are comprehensively outlined. As a result of this endeavor, we will gain a better understanding of myeloid cell heterogeneity, as well as contribute to the development of new therapeutic approaches.

Anti-PD-L1 antibodies promote cellular proliferation by activating the PD-L1-AXL signal relay in liver cancer cells

BACKGROUND

Immune checkpoint inhibitors (ICIs) are emerging treatments for advanced hepatocellular carcinoma (HCC); however, evidence has shown they may induce hyperprogressive disease via unexplained mechanisms.

METHODS

In this study, we investigated the possible stimulative effect of ICIs on programmed cell death-ligand 1 (PD-L1)-harboring liver cancer cells under immunocompetent cell-free conditions.

RESULTS

The sarcomatous HAK-5 cell line displayed the highest expression of PD-L1 among 11 human liver cancer cell lines used in this study. HLF showed moderate expression, while HepG2, Hep3B, and HuH-7 did not show any. Moreover, sarcomatous HCC tissues expressed high levels of PD-L1. We observed approximately 20% increase in cell proliferation in HAK-5 cells treated with anti-PD-L1 antibodies, such as durvalumab and atezolizumab, for 48 h compared with that of those treated with the control IgG and the anti-PD-1 antibody pembrolizumab. No response to durvalumab or atezolizumab was shown in PD-L1-nonexpressing cells. Loss-of-function and gain-of-function experiments for PD-L1 in HAK-5 and HepG2 cells resulted in a significant decrease and increase in cell proliferation, respectively. Phosphorylated receptor tyrosine kinase array and immunoprecipitation revealed direct interactions between PD-L1 and AXL in tumor cells. This was stabilized by extrinsic anti-PD-L1 antibodies in a glycosylated PD-L1-dependent manner. Activation of AXL, triggering signal relay to the Akt and Erk pathways, boosted tumor cell proliferation both in vitro and in xenografted tumors in NOD/SCID mice.

CONCLUSION

Collectively, this suggests that anti-PD-L1 antibodies stimulate cell proliferation via stabilization of the PD-L1-AXL complex in specific types of liver cancer, including in HCC with mesenchymal components.

SIGNIFICANCE

Therapeutic anti-PD-L1 antibodies promote cell proliferation by stabilizing the PD-L1-AXL complex in PD-L1-abundant neoplasms, including in HCC with mesenchymal components. Such a mechanism may contribute to the development of hyperprogressive disease.

Peptide Transporter 1-Mediated Dipeptide Transport Promotes Hepatocellular Carcinoma Metastasis by Activating MAP4K4/G3BP2 Signaling Axis

Cancer metastasis is the leading cause of mortality in patients with hepatocellular carcinoma (HCC). To meet the rapid malignant growth and transformation, tumor cells dramatically increase the consumption of nutrients, such as amino acids. Peptide transporter 1 (PEPT1), a key transporter for small peptides, has been found to be an effective and energy-saving intracellular source of amino acids that are required for the growth of tumor cells. Here, the role of PEPT1 in HCC metastasis and its underlying mechanisms is explored. PEPT1 is upregulated in HCC cells and tissues, and high PEPT1 expression is associated with poor prognosis in patients with HCC. PEPT1 overexpression dramatically promoted HCC cell migration, invasion, and lung metastasis, whereas its knockdown abolished these effects both in vitro and in vivo. Mechanistic analysis revealed that high PEPT1 expression increased cellular dipeptides in HCC cells that are responsible for activating the MAP4K4/G3BP2 signaling pathway, ultimately facilitating the phosphorylation of G3BP2 at Thr227 and enhancing HCC metastasis. Taken together, these findings suggest that PEPT1 acts as an oncogene in promoting HCC metastasis through dipeptide-induced MAP4K4/G3BP2 signaling and that the PEPT1/MAP4K4/G3BP2 axis can serve as a promising therapeutic target for metastatic HCC.

Tumor-Extrinsic Axl Expression Shapes an Inflammatory Microenvironment Independent of Tumor Cell Promoting Axl Signaling in Hepatocellular Carcinoma

The activation of the receptor tyrosine kinase Axl by Gas6 is a major driver of tumorigenesis. Despite recent insights, tumor cell-intrinsic and -extrinsic Axl functions are poorly understood in hepatocellular carcinoma (HCC). Thus, we analyzed the cell-specific aspects of Axl in liver cancer cells and in the tumor microenvironment. We show that tumor-intrinsic Axl expression decreased the survival of mice and elevated the number of pulmonary metastases in a model of resection-based tumor recurrence. Axl expression increased the invasion of hepatospheres by the activation of Akt signaling and a partial epithelial-to-mesenchymal transition (EMT). However, the liver tumor burden of Axl+/+ mice induced by diethylnitrosamine plus carbon tetrachloride was reduced compared to systemic Axl-/- mice. Tumors of Axl+/+ mice were highly infiltrated with cytotoxic cells, suggesting a key immune-modulatory role of Axl. Interestingly, hepatocyte-specific Axl deficiency did not alter T cell infiltration, indicating that these changes are independent of tumor cell-intrinsic Axl. In this context, we observed an upregulation of multiple chemokines in Axl+/+ compared to Axl-/- tumors, correlating with HCC patient data. In line with this, Axl is associated with a cytotoxic immune signature in HCC patients. Together these data show that tumor-intrinsic Axl expression fosters progression, while tumor-extrinsic Axl expression shapes an inflammatory microenvironment.

Neutrophils in cancer: dual roles through intercellular interactions

Neutrophils, the most abundant immune cells in human blood, play crucial and diverse roles in tumor development. In the tumor microenvironment (TME), cancer cells regulate the recruitment and behaviors of neutrophils, transforming some of them into a pro-tumor phenotype. Pro-tumor neutrophils interact with cancer cells in various ways to promote cancer initiation, growth, and metastasis, while anti-tumor neutrophils interact with cancer cells to induce senescence and death. Neutrophils can also interact with other cells in TME, including T cells, macrophages, stromal cells, etc. to exert anti- or pro-tumor functions. In this review, we will analyze the anti- and pro-tumor intercellular interactions mediated by neutrophils, with a focus on generalizing the mechanisms underlying the interaction of neutrophils with tumor cells and T cells. Furthermore, we will provide an overview of cancer treatment strategies targeting neutrophil-mediated cellular interactions.

Intratumoral CXCR4hi neutrophils display ferroptotic and immunosuppressive signatures in hepatoblastoma

Pediatric hepatoblastoma (HB) is the most common primary liver malignancy in infants and children. With great diversity and plasticity, tumor-infiltrating neutrophils were one of the most determining factors for poor prognosis in many malignant tumors. In this study, through bulk RNA sequencing for sorted blood and tumor-infiltrated neutrophils and comparison of neutrophils in tumor and para-tumor tissue by single-cell sequencing, we found that intratumoral neutrophils were composed of heterogenous functional populations at different development stages. Our study showed that terminally differentiated neutrophils with active ferroptosis prevailed in tumor tissue, whereas, in para-tumor, pre-fate naïve neutrophils were dominant and ferroptotic neutrophils dispersed in a broad spectrum of cell maturation. Gene profiling and in vitro T-cell coculture experiment confirmed that one of main functional intratumoral neutrophils was mainly immunosuppressive, which relied on the activation of ferroptosis. Combining the bulk RNA-seq, scRNA-seq data, and immunochemistry staining of tumor samples, CXCL12/CXCR4 chemotaxis pathway was suggested to mediate the migration of neutrophils in tumors as CXCR4 highly expressed by intratumoral neutrophils and its ligand CXCL12 expressed much higher level in tumor than that in para-tumor. Moreover, our study pinpointed that infiltrated CXCR4hi neutrophils, regardless of their differential distribution of cell maturation status in HB tumor and para-tumor regions, were the genuine perpetrators for immune suppression. Our data characterized the ferroptosis-dependent immunosuppression energized by intratumoral CXCR4 expression neutrophils and suggest a potential cell target for cancer immunotherapies.

GAS6/TAM Axis as Therapeutic Target in Liver Diseases

TAM (TYRO3, AXL, and MERTK) protein tyrosine kinase membrane receptors and their vitamin K-dependent ligands GAS6 and protein S (PROS) are well-known players in tumor biology and autoimmune diseases. In contrast, TAM regulation of fibrogenesis and the inflammation mechanisms underlying metabolic dysfunction-associated steatohepatitis (MASH), cirrhosis, and, ultimately, liver cancer has recently been revealed. GAS6 and PROS binding to phosphatidylserine exposed in outer membranes of apoptotic cells links TAMs, particularly MERTK, with hepatocellular damage. In addition, AXL and MERTK regulate the development of liver fibrosis and inflammation in chronic liver diseases. Acute hepatic injury is also mediated by the TAM system, as recent data regarding acetaminophen toxicity and acute-on-chronic liver failure have uncovered. Soluble TAM-related proteins, mainly released from activated macrophages and hepatic stellate cells after hepatic deterioration, are proposed as early serum markers for disease progression. In conclusion, the TAM system is becoming an interesting pharmacological target in liver pathology and a focus of future biomedical research in this field.

From MASH to HCC: the role of Gas6/TAM receptors

Metabolic dysfunction-associated steatohepatitis (MASH) is the replacement term for what used to be called nonalcoholic steatohepatitis (NASH). It is characterized by inflammation and injury of the liver in the presence of cardiometabolic risk factors and may eventually result in the development of hepatocellular carcinoma (HCC), the most common form of primary liver cancer. Several pathogenic mechanisms are involved in the transition from MASH to HCC, encompassing metabolic injury, inflammation, immune dysregulation and fibrosis. In this context, Gas6 (Growth Arrest-Specific 6) and TAM (Tyro3, Axl, and MerTK) receptors may play important roles. The Gas6/TAM family is involved in the modulation of inflammation, lipid metabolism, fibrosis, tumor progression and metastasis, processes which play an important role in the pathophysiology of acute and chronic liver diseases. In this review, we discuss MASH-associated HCC and the potential involvement of the Gas6/TAM system in disease development and progression. In addition, since therapeutic strategies for MASH and HCC are limited, we also speculate regarding possible future treatments involving the targeting of Gas6 or TAM receptors.

Influence of serum Gas6 levels on prognosis in patients with hepatocellular carcinoma

OBJECTIVE

The prediction of prognosis in hepatocellular carcinoma patients is important for switching treatment. The association between circulating growth arrest-specific 6 levels and prognosis in hepatocellular carcinoma patients is unknown.

METHODS

We retrospectively analysed the association between serum growth arrest-specific 6 levels and clinical findings in 132 patients with hepatocellular carcinoma. Serum growth arrest-specific 6 levels were measured using enzyme-linked immunosorbent assay.

RESULTS

Amongst 132 patients, the Barcelona Clinic Liver Cancer stage was classified as 0, A, B, C and D in 19, 48, 41, 18 and 6 patients, respectively. Serum growth arrest-specific 6 levels in hepatocellular carcinoma patients were higher than those in healthy controls (28.4 ng/mL vs. 19.6 ng/mL, P < 0.001), and growth arrest-specific 6 levels were positively correlated with soluble Axl levels. In the entire cohort, high growth arrest-specific 6 levels were associated with a shorter survival period (hazard ratio: 1.78 per 20 ng/mL, 95% confidence interval: 1.01-3.16, P = 0.045). In early and intermediate-stage hepatocellular carcinoma patients treated with transcatheter arterial chemoembolization (n = 59), we determined a cut-off value of 36.4 ng/mL based on the receiver operating characteristic curve to predict death within 3 years, and high growth arrest-specific 6 levels were associated with a high cumulative incidence of portal vein tumour thrombosis (Gray's test: P = 0.010) and shorter overall survival (log-rank: P = 0.005).

CONCLUSIONS

Serum growth arrest-specific 6 levels were associated with prognosis in hepatocellular carcinoma patients. In early and intermediate-stage hepatocellular carcinoma patients who underwent transcatheter arterial chemoembolization, high growth arrest-specific 6 levels were associated with a high incidence of portal vein tumour thrombosis. Circulating growth arrest-specific 6 levels may be a useful prognostic marker in hepatocellular carcinoma patients.

TGFβ1 induces CXCL1 to promote stemness features in lung cancer

Chemokines critically orchestrate the tumorigenesis, metastasis, and stemness features of cancer cells that lead to poor outcomes. High plasma levels of transforming growth factor-β1 (TGFβ1) correlate with poor prognostic features in advanced lung cancer patients, thus suggesting the importance of TGFβ1 in the lung tumor microenvironment. However, the role of chemokines in TGFβ1-induced tumor stemness features remains unclear. Here, we clarify the previously undocumented role of CXCL1 in TGFβ1-induced lung cancer stemness features. CXCL1 and its receptor CXCR2 were significantly upregulated in TGFβ1-induced lung cancer stem cells (CSCs). CXCL1 silencing (shCXCL1) suppressed stemness gene expression, tumorsphere formation, colony formation, drug resistance, and in vivo tumorigenicity in TGFβ1-induced lung tumorspheres. Immunohistochemistry staining showed that patients with stage II/III lung cancer had higher expression levels of CXCL1. The levels of CXCL1 were positively associated with lymph node metastasis and correlated with the expression of the CSC transcription factor Oct-4. Furthermore, online database analysis revealed that CXCL1 expression was negatively correlated with lung cancer survival in patients. Patients with high TGFβ1/CXCL1/CD44 co-expression had a worse survival rate. We suggest that CXCL1 serves as a crucial factor in TGFβ1-induced stemness features of lung cancer.

IGFBP2 drives epithelial-mesenchymal transition in hepatocellular carcinoma via activating the Wnt/β-catenin pathway

Metastasis has emerged as a major impediment to achieve successful therapeutic outcomes in hepatocellular carcinoma (HCC). Nonetheless, the intricate molecular mechanisms governing the progression of HCC remain elusive. Herein, we present evidence highlighting the influence exerted by insulin-like growth factor-binding protein 2 (IGFBP2) as a potent oncogene driving the malignant phenotype. Our investigation reveals a marked elevation of IGFBP2 expression in primary tumors, concomitant with the presence of mesenchymal biomarkers in HCC. Through in vitro and in vivo experimentation, we demonstrate that the overexpression of IGFBP2 expedites the progression of epithelial-mesenchymal transition (EMT) and facilitates the metastatic potential of HCC cells, chiefly mediated by the Wnt/β-catenin signaling pathway. Notably, knockdown of IGFBP2 significantly decreased the expression of total and nuclear β-catenin, N-cadherin and vimentin in the treatment of the specific activator of Wnt/β-catenin CHIR-99021. Collectively, our findings identify IGFBP2 as a pivotal regulator within the HCC EMT axis, whereby its overexpression confers the distinctly aggressive clinical features characteristic of the disease.

Neutrophil membrane-based nanotherapeutics: Propitious paradigm shift in the management of cancer

Cancer is the leading cause of death across the globe, with 19.3 million new cancer cases and 10 million deaths in the year 2020. Conventional treatment modalities have numerous pitfalls, such as off-site cytotoxicity and poor bioavailability. Nanocarriers (NCs) have been explored to deliver various therapeutic moieties such as chemotherapeutic agents and photothermal agents, etc. However, several limitations, such as rapid clearance by the reticuloendothelial system, poor extravasation into the tumor microenvironment, and low systemic half-life are roadblocks to successful clinical translation. To circumvent the pitfalls of currently available treatment modalities, neutrophil membrane (NM)-based nanotherapeutics have emerged as a promising platform for cancer management. Their versatile features such as natural tumor tropism, tumor-specific accumulation, and prevention from rapid clearance owing to their autologous nature make them an effective anticancer NCs. In this manuscript, we have discussed various methods for isolation, coating and characterization of NM. We have discussed the role of NM-coated nanotherapeutics as neoadjuvant and adjuvant in different treatment modalities, such as chemotherapy, photothermal and photodynamic therapies with rationales behind their inclusion. Clinical hurdles faced during the bench-to-bedside translation with possible solutions have been discussed. We believe that in the upcoming years, NM-coated nanotherapeutics will open a new horizon in cancer management.

Immune System and Hepatocellular Carcinoma (HCC): New Insights into HCC Progression

According to the WHO's recently released worldwide cancer data for 2020, liver cancer ranks sixth in morbidity and third in mortality among all malignancies. Hepatocellular carcinoma (HCC), the most common kind of liver cancer, accounts approximately for 80% of all primary liver malignancies and is one of the leading causes of death globally. The intractable tumor microenvironment plays an important role in the development and progression of HCC and is one of three major unresolved issues in clinical practice (cancer recurrence, fatal metastasis, and the refractory tumor microenvironment). Despite significant advances, improved molecular and cellular characterization of the tumor microenvironment is still required since it plays an important role in the genesis and progression of HCC. The purpose of this review is to present an overview of the HCC immune microenvironment, distinct cellular constituents, current therapies, and potential immunotherapy methods.

Collagen-induced DDR1 upregulates CXCL5 to promote neutrophil extracellular traps formation and Treg infiltration in breast cancer

Neutrophil extracellular traps (NETs) have been implicated in many cancers, but the regulatory mechanisms in the context of breast cancer have not been thoroughly discussed. This study proposed a mechanism based on collagen-activated DDR1/CXCL5 for NET formation in breast cancer. Through TCGA and GEO-based bioinformatics analysis, we examined the DDR1 expression and the correlation of CXCL5 with immune cell infiltration in breast cancer. It was found that high DDR1 expression was correlated with poor prognosis of patients with breast cancer, and CXCL5 was positively correlated with neutrophil and Treg infiltration. Expression of DDR1 and CXCL5 was determined in collagen-treated breast cancer cells, the malignant phenotypes of which were evaluated by ectopic expression and knockdown methods. Collagen-activated DDR1 upregulated CXCL5 expression, resulting in augmented malignant phenotypes of breast cancer cells in vitro. The formation of NETs caused promotion in the differentiation and immune infiltration of Tregs in breast cancer. A in situ breast cancer mouse model was constructed, where NET formation and lung metastasis of breast cancer cells were observed. The differentiation of CD4+ T cells isolated from the mouse model was induced into Tregs, followed by Treg infiltration assessment. It was further confirmed in vivo that DDR1/CXCL5 induced the formation of NETs to promote immune infiltration of Tregs, driving tumor growth and metastasis. Accordingly, our results provided new mechanistic insights for an understanding of the role of collagen-mediated DDR1/CXCL5 in formation of NETs and Treg infiltration, revealing potential targets for therapeutic intervention of breast cancer.

The liver cancer immune microenvironment: Therapeutic implications for hepatocellular carcinoma

The liver is the sixth most common site of primary cancer in humans and the fourth leading cause of cancer-related death in the world. Hepatocellular carcinoma (HCC) accounts for 90% of liver cancers. HCC is a prevalent disease with a progression that is modulated by the immune system. Half of the patients with HCC receive systemic therapies, traditionally sorafenib or lenvatinib, as a first-line therapy. In the last few years, immune-checkpoint inhibitors (ICIs) have revolutionized cancer therapy and have gained an increased interest in the treatment of HCC. In 2020, the combination of atezolizumab (anti-programmed death-ligand 1) and bevacizumab (anti-vascular endothelial growth factor) improved overall survival over sorafenib, resulting in Food and Drug Administration (FDA) approval as a first-line treatment for patients with advanced HCC. Despite these major advances, a better molecular and cellular characterization of the tumor microenvironment is still needed because it has a crucial role in the development and progression of HCC. Inflamed (hot) and noninflamed (cold) HCC tumors and genomic signatures have been associated with response to ICIs. However, there are no additional biomarkers to guide clinical decision-making. Other immune-targeting strategies, such as adoptive T-cell transfer, vaccination, and virotherapy, are currently under development. This review provides an overview on the HCC immune microenvironment, different cellular players, current available immunotherapies, and potential immunotherapy modalities.

Extracellular alkaline pH enhances migratory behaviors of hepatocellular carcinoma cells as a caution against the indiscriminate application of alkalinizing drug therapy: In vitro microscopic studies

The migratory process is a highly organized, differentiated, and polarized stage by which many signaling pathways are regulated to control cell migration. Since the significant evidence of migrating cells is the reorganization of the cytoskeleton. In the recent study, the cell migration model was assessed on the fact that any disruption obtained in the cellular monolayer confluent, may cause stimulation for surrounding cells to migrate. We attempt to demonstrate the morphological alterations associated with these migrating cells. In this case, sterilized 1 N NaOH (1 µl) was used as alkaline burnt. It leads to scratching the monolayer of hepatocellular carcinoma (HLF cell line) allowing cells to lose their connection. Scanning electron microscopy (SEM), fluorescence microscopy, light inverted microscopy, and dark field were used for discovering the morphological alterations associated with migrating cancer cells. The findings show that cells exhibited distinctive alterations including a polarizing stage, accumulation of the actin nodules in front of the nucleus, and protrusions. Nuclei appeared as lobulated shapes during migration. Lamellipodia and uropod were extended as well. Additionally, TGFβ1 proved its expression in HLF and SNU449 after their stimulation. It is demonstrated that hepatocellular carcinoma cells can migrate after their stimulation and there is a caution against the indiscriminate application of alkalinizing drug therapy.

PRAME Is a Novel Target of Tumor-Intrinsic Gas6/Axl Activation and Promotes Cancer Cell Invasion in Hepatocellular Carcinoma

(1) Background: Activation of the receptor tyrosine kinase Axl by Gas6 fosters oncogenic effects in hepatocellular carcinoma (HCC), associating with increased mortality of patients. The impact of Gas6/Axl signaling on the induction of individual target genes in HCC and its consequences is an open issue. (2) Methods: RNA-seq analysis of Gas6-stimulated Axl-proficient or Axl-deficient HCC cells was used to identify Gas6/Axl targets. Gain- and loss-of-function studies as well as proteomics were employed to characterize the role of PRAME (preferentially expressed antigen in melanoma). Expression of Axl/PRAME was assessed in publicly available HCC patient datasets and in 133 HCC cases. (3) Results: Exploitation of well-characterized HCC models expressing Axl or devoid of Axl allowed the identification of target genes including PRAME. Intervention with Axl signaling or MAPK/ERK1/2 resulted in reduced PRAME expression. PRAME levels were associated with a mesenchymal-like phenotype augmenting 2D cell migration and 3D cell invasion. Interactions with pro-oncogenic proteins such as CCAR1 suggested further tumor-promoting functions of PRAME in HCC. Moreover, PRAME showed elevated expression in Axl-stratified HCC patients, which correlates with vascular invasion and lowered patient survival. (4) Conclusions: PRAME is a bona fide target of Gas6/Axl/ERK signaling linked to EMT and cancer cell invasion in HCC.

HtrA2 Independently Predicts Poor Prognosis and Correlates with Immune Cell Infiltration in Hepatocellular Carcinoma

High-temperature requirement protein A2 (HtrA2), a mitochondrial protein, is related to apoptosis regulation. However, the role of HtrA2 in hepatocellular carcinoma (HCC) remains unclear. In the present study, we explored the prognostic value and expression pattern of HtrA2 in HCC and confirmed its independent value for predicting outcomes via Cox analyses. LinkedOmics and GEPIA2 were used to construct the coexpression and functional networks of HtrA2. Additionally, the data obtained from TCGA was analyzed to investigate the relationship between the infiltration of immune cells and HtrA2 mRNA expression. Finally, the expression pattern of HtrA2 in HCC was confirmed by wet-lab experiments. The results showed high HtrA2 expression (P < 0.001) presented in tumor tissues in TCGA-HCC. Moreover, high HtrA2 expression was confirmed to be associated with poor HCC patient survival (P < 0.05). HtrA2 has also been recognized as an essential risk factor for overall survival (P=0.01, HR = 1.654, 95% CI 1.128-2.425), disease-specific survival (P=0.004, HR = 2.204, 95% CI 1.294-3.753), and progression-free interval (P=0.007, HR = 1.637, 95% CI 1.145-2.341) of HCC. HCC patients with low HtrA2 methylation had worse overall survival than patients with high methylation (P=0.0019). Functional network analysis suggests that HtrA2 regulates mitochondrial homeostasis through pathways involving multiple microRNAs and transcription factors in HCC. In addition, HtrA2 expression correlated with infiltrating levels of multiple immune cell populations. At last, increased expression of HtrA2 in HCC was confirmed using wet-lab experiments. Our study provides evidence that the upregulation of HtrA2 in HCC is an independent predictor of prognosis. Our results provide the foundation for further study on the roles of HtrA2 in HCC tumorigenesis.

Diverse Neutrophil Functions in Cancer and Promising Neutrophil-Based Cancer Therapies

Neutrophils represent the most abundant cell type of leukocytes in the human blood and have been considered a vital player in the innate immune system and the first line of defense against invading pathogens. Recently, several studies showed that neutrophils play an active role in the immune response during cancer development. They exhibited both pro-oncogenic and anti-tumor activities under the influence of various mediators in the tumor microenvironment. Neutrophils can be divided into several subpopulations, thus contradicting the traditional concept of neutrophils as a homogeneous population with a specific function in the innate immunity and opening new horizons for cancer therapy. Despite the promising achievements in this field, a full understanding of tumor-neutrophil interplay is currently lacking. In this review, we try to summarize the current view on neutrophil heterogeneity in cancer, discuss the different communication pathways between tumors and neutrophils, and focus on the implementation of these new findings to develop promising neutrophil-based cancer therapies.

Therapy-induced modulation of extracellular vesicles in hepatocellular carcinoma

Despite rapid development of anti-tumorigenic treatments, the clinical outcome for hepatocellular carcinoma (HCC) is still far from satisfactory. With a deeper understanding about tumor microenvironment (TME), the critical role of extracellular vesicles (EVs) as intercellular liaison has come into spotlight. The dynamic functionality of these nanoparticles revealed cancer cells can employ both tumor and non-tumorous components for their own benefit, so as to mediate cell-to-cell communication and interchange of oncogenic biomolecules. Increasing studies on HCC-derived EVs have identified various irregulated biomolecules, that may serve as biomarkers or therapeutic targets. In this review, we first introduce the current knowledge about EVs and how they operate to maintain a healthy liver microenvironment. We then summarize some of the aberrant observations reported on HCC-derived EVs and how they contribute to HCC pathogenesis. Finally, we describe how current treatments for HCC alter behavior of EVs, which may shed light for potential prognostic markers and therapeutic strategies.

KIAA1199 drives immune suppression to promote colorectal cancer liver metastasis by modulating neutrophil infiltration

BACKGROUND AND AIMS

Metastasis is the primary cause of cancer mortality, and colorectal cancer (CRC) frequently metastasizes to the liver. Our previous studies demonstrated the critical role of KIAA1199 in tumor invasion and metastasis in CRC. In the present study, we described an immune regulatory effect of KIAA1199 that creates a permissive environment for metastasis.

APPROACH AND RESULTS

Flow cytometry was used to examine the effects of KIAA1199 on the infiltration of tumor immune cells. Neutrophils and T cells were isolated, stimulated, and/or cultured for in vitro function assays. In the patients with CRC, high expression levels of KIAA1199 were associated with an increased neutrophil infiltration into the liver. This result was further validated in mouse metastasis models. The increased influx of neutrophils contributed to the KIAA1199-driven CRC liver metastasis. Mechanistically, KIAA1199 activated the TGFβ signaling pathway by interacting with the TGFBR1/2 to stimulate CXCL1 and CXCL3 production, thereby driving the aggregation of immunosuppressive neutrophils. Genetic blockade or pharmacologic inhibition of KIAA1199 restored tumor immune infiltration, impeded tumor progression, and potentiated response to immune checkpoint blockade (ICB).

CONCLUSIONS

These findings indicated that KIAA1199 could facilitate the liver infiltration of immunosuppressive neutrophils via the TGFβ-chemokine (C-X-C motif) ligand (CXCL)3/1-CXCR2 axis, which might be clinically targeted for the treatment of hepatic metastasis.

The immunosuppressive tumor microenvironment in hepatocellular carcinoma-current situation and outlook

Hepatocellular carcinoma (HCC) is one of the most severe malignant tumors that threaten human health, and its incidence is still on the rise recently. In spite of the current emerging treatment strategies, the overall prognosis of liver cancer remains worrying. Currently, immunotherapy has become a new research-active spot. The emergence of immune checkpoints and targeted immune cell therapy can significantly improve the prognosis of HCC. To a large extent, the effect of this immunotherapy depends on the tumor immune microenvironment (TME), an intricate system in which cancer cells and other non-cancer cells display various interactions. Understanding the immunosuppressive situation of these cells, along with the malignant behavior of cancer cells, can assist us to design new therapeutic approaches against tumors. Therefore, it is necessary to clarify the TME of HCC for further improvement of clinical treatment. This review discussed the functions of several immunosuppressive cells and exosomes in the latest research progress of HCC, including cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs) and tumor-associated neutrophils (TANs) interacted actively to facilitate tumor progression. It further describes the treatment methods targeting them and the potential that needs to be explored in the future.

Neutrophils: Musketeers against immunotherapy

Neutrophils, the most copious leukocytes in human blood, play a critical role in tumorigenesis, cancer progression, and immune suppression. Recently, neutrophils have attracted the attention of researchers, immunologists, and oncologists because of their potential role in orchestrating immune evasion in human diseases including cancer, which has led to a hot debate redefining the contribution of neutrophils in tumor progression and immunity. To make this debate fruitful, this review seeks to provide a recent update about the contribution of neutrophils in immune suppression and tumor progression. Here, we first described the molecular pathways through which neutrophils aid in cancer progression and orchestrate immune suppression/evasion. Later, we summarized the underlying molecular mechanisms of neutrophil-mediated therapy resistance and highlighted various approaches through which neutrophil antagonism may heighten the efficacy of the immune checkpoint blockade therapy. Finally, we have highlighted several unsolved questions and hope that answering these questions will provide a new avenue toward immunotherapy revolution.

Cardiac fibroblast heat shock protein 47 aggravates cardiac fibrosis post myocardial ischemia–reperfusion injury by encouraging ubiquitin specific peptidase 10 dependent Smad4 deubiquitination

Despite complications were significantly reduced due to the popularity of percutaneous coronary intervention (PCI) in clinical trials, reperfusion injury and chronic cardiac remodeling significantly contribute to poor prognosis and rehabilitation in AMI patients. We revealed the effects of HSP47 on myocardial ischemia–reperfusion injury (IRI) and shed light on the underlying molecular mechanism. We generated adult mice with lentivirus-mediated or miRNA (mi1/133TS)-aided cardiac fibroblast-selective HSP47 overexpression. Myocardial IRI was induced by 45-min occlusion of the left anterior descending (LAD) artery followed by 24 h reperfusion in mice, while ischemia-mediated cardiac remodeling was induced by four weeks of reperfusion. Also, the role of HSP47 in fibrogenesis was evaluated in cardiac fibroblasts following hypoxia–reoxygenation (HR). Extensive HSP47 was observed in murine infarcted hearts, human ischemic hearts, and cardiac fibroblasts and accelerated oxidative stress and apoptosis after myocardial IRI. Cardiac fibroblast-selective HSP47 overexpression exacerbated cardiac dysfunction caused by chronic myocardial IRI and presented deteriorative fibrosis and cell proliferation. HSP47 upregulation in cardiac fibroblasts promoted TGFβ1–Smad4 pathway activation and Smad4 deubiquitination by recruiting ubiquitin-specific peptidase 10 (USP10) in fibroblasts. However, cardiac fibroblast specific USP10 deficiency abolished HSP47-mediated fibrogenesis in hearts. Moreover, blockage of HSP47 with Col003 disturbed fibrogenesis in fibroblasts following HR. Altogether, cardiac fibroblast HSP47 aggravates fibrosis post-myocardial IRI by enhancing USP10-dependent Smad4 deubiquitination, which provided a potential strategy for myocardial IRI and cardiac remodeling.

CXCL5: A coachman to drive cancer progression

Chemokines are a class of pro-inflammatory cytokines that can recruit and activate chemotactic cells. C‐X‐C motif chemokine ligand 5 (CXCL5) is a member of the chemokine family binding CXCR2 (C-X-C Motif Chemokine Receptor 2), a G-protein coupled receptor. Accumulated evidence has shown that dysregulated CXCL5 participates in tumor metastasis and angiogenesis in human malignant tumors. In this review, we summarized the advances in research on CXCL5, including its dysregulation in different tumors and the mechanism associated with tumor behavior (formation of the immunosuppressive microenvironment, promotion of tumor angiogenesis, and metastasis). We also summarized and discussed the perspective about the potential application of CXCL5 in tumor therapy targeting the tumor inflammatory microenvironment.

Tumor-associated neutrophils and neutrophil-targeted cancer therapies

Neutrophils are the frontline cells in response to microbial infections and are involved in a range of inflammatory disorders in the body. In recent years, neutrophils have gained considerable attention in their involvement of complex roles in tumor development and progression. Tumor-associated neutrophils (TANs) that accumulate in local region could be triggered by external stimuli from tumor microenvironment (TME) and switch between anti- and pro-tumor phenotypes. The anti-tumor neutrophils kill tumor cells through direct cytotoxic effects as well as indirect effects by activating adaptive immune responses. In contrast, the pro-tumor phenotype of neutrophils might be associated with cell proliferation, angiogenesis, and immunosuppression in TME. More recently, neutrophils have been proposed as a potential target in cancer therapy for their ability to diminish the pro-tumor pathways, such as by immune checkpoint blockade. This review discusses the complex roles of neutrophils in TME and highlights the strategies in neutrophil targeting in cancer treatment with a particular focus on the progresses of ongoing clinical trials involving neutrophil-targeted therapies.

Proteomic and Metabolomic Characterization of SARS-CoV-2-Infected Cynomolgus Macaque at Early Stage

Although tremendous effort has been exerted to elucidate the pathogenesis of severe COVID-19 cases, the detailed mechanism of moderate cases, which accounts for 90% of all patients, remains unclear yet, partly limited by lacking the biopsy tissues. Here, we established the COVID-19 infection model in cynomolgus macaques (CMs), monitored the clinical and pathological features, and analyzed underlying pathogenic mechanisms at early infection stage by performing proteomic and metabolomic profiling of lung tissues and sera samples from COVID-19 CMs models. Our data demonstrated that innate immune response, neutrophile and platelet activation were mainly dysregulated in COVID-19 CMs. The symptom of neutrophilia, lymphopenia and massive "cytokines storm", main features of severe COVID-19 patients, were greatly weakened in most of the challenged CMs, which are more semblable as moderate patients. Thus, COVID-19 model in CMs is rational to understand the pathogenesis of moderate COVID-19 and may be a candidate model to assess the safety and efficacy of therapeutics and vaccines against SARS-CoV-2 infection.

Genomically Silent Refractory Gastric Cancer in a Young Patient Exhibits Overexpression of CXCL5

Gastric cancer is the third leading cause of cancer-related deaths, with more than one million new cases and approximately 841,000 deaths annually worldwide. We report a case of a young patient (25 years old) with an aggressive form of gastric cancer. The patient had previously been treated for Helicobacter pylori (H. pylori), which is a main risk factor for developing gastric cancer. Genetic testing showed an E-cadherin (CDH1) germline mutation of unknown significance. After eight cycles of chemotherapy, a positron emission tomography (PET) scan showed disease progression with an enlarging hypermetabolic right adnexal mass suspicious for metastatic disease. Tumor pathology demonstrated invasive and poorly differentiated gastric carcinoma. The analysis of the tumor biopsy indicated the very high expression of a chemokine, C-X-C motif chemokine 5 (CXCL5). The combination of H. pylori infection with an existence of a rare CDH1 mutation could have contributed to this aggressive gastric cancer.

Tumor-associated Exosomes Are Involved in Hepatocellular Carcinoma Tumorigenesis, Diagnosis, and Treatment

Hepatocellular carcinoma (HCC) has become a challenging disease worldwide. There are still limitations in the diagnosis and treatment of HCC, and its high metastatic capacity and high recurrence rate are the main reasons for its poor prognosis. The ability of extracellular vesicles (EVs) to transfer functionally-active substances and their widespread presence in almost all body fluids suggest their unprecedented potential in the study of various cancers. The unique physicochemical properties of EVs determine their potential as antitumor vaccines and drug carriers. In the last decade, the study of EVs in HCC has evolved from a single hot topic to a system with considerable scale. This paper summarizes the role of EVs, especially exosomes, in the occurrence, metastasis and tumor immunity of HCC, reviews their applications in tumor diagnosis, prognosis and treatment, describes the pros and cons of these studies, and looks forward towards the future research directions of EVs in HCC.

Neutrophil phenotypes and functions in cancer: A consensus statement

Neutrophils are the first responders to infection and inflammation and are thus a critical component of innate immune defense. Understanding the behavior of neutrophils as they act within various inflammatory contexts has provided insights into their role in sterile and infectious diseases; however, the field of neutrophils in cancer is comparatively young. Here, we summarize key concepts and current knowledge gaps related to the diverse roles of neutrophils throughout cancer progression. We discuss sources of neutrophil heterogeneity in cancer and provide recommendations on nomenclature for neutrophil states that are distinct in maturation and activation. We address discrepancies in the literature that highlight a need for technical standards that ought to be considered between laboratories. Finally, we review emerging questions in neutrophil biology and innate immunity in cancer. Overall, we emphasize that neutrophils are a more diverse population than previously appreciated and that their role in cancer may present novel unexplored opportunities to treat cancer.

Epithelial–mesenchymal transition: The history, regulatory mechanism, and cancer therapeutic opportunities

Epithelial–mesenchymal transition (EMT) is a program wherein epithelial cells lose their junctions and polarity while acquiring mesenchymal properties and invasive ability. Originally defined as an embryogenesis event, EMT has been recognized as a crucial process in tumor progression. During EMT, cell–cell junctions and cell–matrix attachments are disrupted, and the cytoskeleton is remodeled to enhance mobility of cells. This transition of phenotype is largely driven by a group of key transcription factors, typically Snail, Twist, and ZEB, through epigenetic repression of epithelial markers, transcriptional activation of matrix metalloproteinases, and reorganization of cytoskeleton. Mechanistically, EMT is orchestrated by multiple pathways, especially those involved in embryogenesis such as TGFβ, Wnt, Hedgehog, and Hippo, suggesting EMT as an intrinsic link between embryonic development and cancer progression. In addition, redox signaling has also emerged as critical EMT modulator. EMT confers cancer cells with increased metastatic potential and drug resistant capacity, which accounts for tumor recurrence in most clinic cases. Thus, targeting EMT can be a therapeutic option providing a chance of cure for cancer patients. Here, we introduce a brief history of EMT and summarize recent advances in understanding EMT mechanisms, as well as highlighting the therapeutic opportunities by targeting EMT in cancer treatment.

Neutrophils and polymorphonuclear myeloid-derived suppressor cells: an emerging battleground in cancer therapy

Neutrophils are central mediators of innate and adaptive immunity and first responders to tissue damage. Although vital to our health, their activation, function, and resolution are critical to preventing chronic inflammation that may contribute to carcinogenesis. Cancers are associated with the expansion of the neutrophil compartment with an escalation in the number of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) in the peripheral circulation and tumor microenvironment. Although phenotypically similar to classically activated neutrophils, PMN-MDSC is pathologically activated and immunosuppressive in nature. They dynamically interact with other cell populations and tissue components and convey resistance to anticancer therapies while accelerating disease progression and metastatic spread. Cancer-associated neutrophilia and tumor infiltration of neutrophils are significant markers of poor outcomes in many cancers. Recently, there has been significant progress in the identification of molecular markers of PMN-MDSC providing insights into the central role of PMN-MDSC in the local tumor microenvironment as well as the systemic immune response in cancer. Further advances in sequencing and proteomics techniques will improve our understanding of their diverse functionalities and the complex molecular mechanisms at play. Targeting PMN-MDSC is currently one of the major focus areas in cancer research and several signaling pathways representing possible treatment targets have been identified. Positive results from preclinical studies clearly justify the current investigation in drug development and thus novel therapeutic strategies are being evaluated in clinical trials. In this review, we discuss the involvement of PMN-MDSC in cancer initiation and progression and their potential as therapeutic targets and clinical biomarkers in different cancers.

A highly branched α-D-glucan facilitates antitumor immunity by reducing cancer cell CXCL5 expression

Tumor immunotherapy has emerged as a major pillar of anticancer therapeutic strategies. Natural polysaccharides, known for their strong immunomodulatory activities with relatively low cost and toxicity, are becoming promising prospects for cancer immunotherapy. In this study, we investigated the antitumor mechanism of JNY2PW, a highly branched α-D-glucan previously purified from the traditional marine Chinese medicine Arca inflata. JNY2PW was shown to enhance the sensitivity of tumor cells to co-culture macrophage supernatants by decreasing cancer cell CXCL5 expression. Furthermore, JNY2PW exerted antitumor effects without obvious toxic side effects in tumor-bearing mice by triggering the Akt/mTOR and ERK/GSK3β/β-catenin pathways and attenuating expression of CXCL5 in cancer cells. Remarkably, JNY2PW reduced tumor proliferation and dampened CXCL5 expression in tumor cells overexpressing CXCL5 both in vitro and in vivo. Additionally, JNY2PW blocked epithelial-mesenchymal transition (EMT) in both CXCL5-overexpressing and wild type tumor cells. Our data therefore uncovered a previously unrecognized antitumor mechanism for JNY2PW, suggesting that JNY2PW is a promising adjuvant as an immunomodulator for cancer immunotherapy.

Neutrophils as potential therapeutic targets in hepatocellular carcinoma

The success of atezolizumab plus bevacizumab treatment contributed to a shift in systemic therapies for hepatocellular carcinoma (HCC) towards combinations that include cancer immunotherapeutic agents. Thus far, the principal focus of cancer immunotherapy has been on interrupting immune checkpoints that suppress antitumour lymphocytes. As well as lymphocytes, the HCC environment includes numerous other immune cell types, among which neutrophils are emerging as an important contributor to the pathogenesis of HCC. A growing body of evidence supports neutrophils as key mediators of the immunosuppressive environment in which some cancers develop, as well as drivers of tumour progression. If neutrophils have a similar role in HCC, approaches that target or manipulate neutrophils might have therapeutic benefits, potentially including sensitization of tumours to conventional immunotherapy. Several neutrophil-directed therapies for patients with HCC (and other cancers) are now entering clinical trials. This Review outlines the evidence in support of neutrophils as drivers of HCC and details their mechanistic roles in development, progression and metastasis, highlighting the reasons that neutrophils are well worth investigating despite the challenges associated with studying them. Neutrophil-modulating anticancer therapies entering clinical trials are also summarized.

The Bright and the Dark Side of TGF-β Signaling in Hepatocellular Carcinoma: Mechanisms, Dysregulation, and Therapeutic Implications

Simple Summary

Transforming growth factor β (TGF-β) signaling is a preeminent regulator of diverse cellular and physiological processes. Frequent dysregulation of TGF-β signaling has been implicated in cancer. In hepatocellular carcinoma (HCC), the most prevalent form of primary liver cancer, the autocrine and paracrine effects of TGF-β have paradoxical implications. While acting as a potent tumor suppressor pathway in the early stages of malignancy, TGF-β diverts to a promoter of tumor progression in the late stages, reflecting its bright and dark natures, respectively. Within this context, targeting TGF-β represents a promising therapeutic option for HCC treatment. We discuss here the molecular properties of TGF-β signaling in HCC, attempting to provide an overview of its effects on tumor cells and the stroma. We also seek to evaluate the dysregulation mechanisms that mediate the functional switch of TGF-β from a tumor suppressor to a pro-tumorigenic signal. Finally, we reconcile its biphasic nature with the therapeutic implications.

Abstract

Hepatocellular carcinoma (HCC) is associated with genetic and nongenetic aberrations that impact multiple genes and pathways, including the frequently dysregulated transforming growth factor β (TGF-β) signaling pathway. The regulatory cytokine TGF-β and its signaling effectors govern a broad spectrum of spatiotemporally regulated molecular and cellular responses, yet paradoxically have dual and opposing roles in HCC progression. In the early stages of tumorigenesis, TGF-β signaling enforces profound tumor-suppressive effects, primarily by inducing cell cycle arrest, cellular senescence, autophagy, and apoptosis. However, as the tumor advances in malignant progression, TGF-β functionally switches to a pro-tumorigenic signal, eliciting aggressive tumor traits, such as epithelial–mesenchymal transition, tumor microenvironment remodeling, and immune evasion of cancer cells. On this account, the inhibition of TGF-β signaling is recognized as a promising therapeutic strategy for advanced HCC. In this review, we evaluate the functions and mechanisms of TGF-β signaling and relate its complex and pleiotropic biology to HCC pathophysiology, attempting to provide a detailed perspective on the molecular determinants underlying its functional diversion. We also address the therapeutic implications of the dichotomous nature of TGF-β signaling and highlight the rationale for targeting this pathway for HCC treatment, alone or in combination with other agents.

Role of Exosomes in Immune Microenvironment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. Since most patients with HCC are diagnosed at the intermediate or advanced stage and because HCC has a high incidence of metastasis and recurrence, it is one of the leading causes of cancer death. Exosomes are a subtype of extracellular vesicles and are typically 30–150 nm in diameter. Originating from endosomes, they can be secreted by almost all living cells. They are widely present in various body fluids and serve as an important medium for the interactions between cells. A series of studies have revealed that exosomes-mediated intercellular transfer of proteins, nucleic acids, and metabolites plays a crucial role in the initiation and progression of HCC, hypoxia and angiogenesis, chemotherapy sensitivity, and cell death mode and regulates the immune microenvironment. In this paper, we reviewed the recent researches on the multiple roles of tumor-associated exosomes in the progression of HCC. We laid particular focus on those researches that reveal how exosomes regulate the tumor immune microenvironment (TIME) and how exosomal cargos affect the progression of HCC. Besides, we emphasize some prospective directions to achieve a more accurate and complete analysis of the HCC immune microenvironment.

TAM Receptors in the Pathophysiology of Liver Disease

TAM receptors (Tyro3, Axl and MerTK) are a family of tyrosine kinase receptors that are expressed in a variety of cell populations, including liver parenchymal and non-parenchymal cells. These receptors are vital for immune homeostasis, as they regulate the innate immune response by suppressing inflammation via toll-like receptor inhibition and by promoting tissue resolution through efferocytosis. However, there is increasing evidence indicating that aberrant TAM receptor signaling may play a role in pathophysiological processes in the context of liver disease. This review will explore the roles of TAM receptors and their ligands in liver homeostasis as well as a variety of disease settings, including acute liver injury, steatosis, fibrosis, cirrhosis-associated immune dysfunction and hepatocellular carcinoma. A better understanding of our current knowledge of TAM receptors in liver disease may identify new opportunities for disease monitoring as well as novel therapeutic targets. Nonetheless, this review also aims to highlight areas where further research on TAM receptor biology in liver disease is required.

Impact of cancer cell-intrinsic features on neutrophil behavior

Neutrophils are multifaceted innate immune cells that play a significant role in the progression of cancer by exerting both pro- and anti-tumorigenic functions. The crosstalk between cancer cells and neutrophils is complex and emerging evidence is pointing at cancer cell-intrinsic programs regulating neutrophil abundance, phenotype and function. Cancer cell-derived soluble mediators are key players in modulating the interaction with neutrophils. Here, we review how intrinsic features of cancer cells, including cancer cell genetics, epigenetics, signaling, and metabolism, manipulate neutrophil behavior and how to target these processes to impact cancer progression. A molecular understanding of cancer cell-intrinsic properties that shape the crosstalk with neutrophils will provide novel therapeutic strategies for personalized immunomodulation in cancer patients.

Neutrophil Extracellular Traps (NETs) in Cancer Metastasis

Metastasis is the leading cause of cancer related morbidity and mortality. The metastatic process involves several identifiable biological stages, including tumor cell dissemination, intravasation, and the extravasation of circulating cancer cells to facilitate colonization at a distant site. Immune cell infiltration and inflammation within the tumor microenvironment coincide with tumor progression and metastatic spread and are thought to be the key mediators of this complex process. Amongst many infiltrating cells, neutrophils have recently emerged as an important player in fueling tumor progression, both in animal models and cancer patients. The production of Neutrophil Extracellular Traps (NETs) is particularly important in the pathogenesis of the metastatic cascade. NETs are composed of web-like DNA structures with entangled proteins that are released in response to inflammatory cues in the environment. NETs play an important role in driving tumor progression both in experimental and clinical models. In this review, we aim to summarize the current advances in understanding the role of NETs in cancer, with a specific focus on their role in promoting premetastatic niche formation, interaction with circulating cancer cells, and in epithelial to mesenchymal transition during cancer metastasis. We will furthermore discuss the possible role and different treatment options for targeting NETs to prevent tumor progression.

Resveratrol inhibits the migration, invasion and epithelial-mesenchymal transition in liver cancer cells through up- miR-186-5p expression

To investigate the molecular mechanism of resveratrol inhibiting the metastasis of liver cancer . HepG2 and Huh7 cells were treated with different concentrations of resveratrol, and the cell viability was determined by CCK-8 assay to determine the optimal concentration of resveratrol for subsequent experiments. The expressions of miR-186-5p in liver cancer tissues and liver cancer cells were determined by quantitative real-time RT-PCR. The migration and invasion of HepG2 and Huh7 cells were detected by wound healing assay and Transwell assay, and the expression levels of epithelial-mesenchymal transition (EMT) related proteins were determined by Western blotting. Resveratrol with concentration of had no effect on the viability of HepG2 and Huh7 cells, so the concentration of resveratrol in subsequent experiments was 6.25 μmol/L. Resveratrol inhibited the wound healing and invasion of liver cancer cells; increased the expression of E-cadherin, and decreased the expression of vimentin and Twist1. The expression of miR-186-5p was significantly down-regulated in liver cancer tissues and cells compared with the adjacent tissues and normal liver cells (both <0.05). Furthermore, resveratrol induced the expression of miR-186-5p in liver cancer cells (both <0.01). Overexpression of miR-186-5p suppressed the migration, invasion and EMT of liver cancer cells. Knockdown of miR-186-5p blocked the inhibition effects of resveratrol on the migration, invasion and EMT of liver cancer cells. Resveratrol could inhibit the metastasis of liver cancer , which might be associated with up-regulating miR-186-5p.

The Recruitment of Neutrophils to the Tumor Microenvironment Is Regulated by Multiple Mediators

Neutrophils sense and migrate towards chemotactic factors released at sites of infection/inflammation and contain the affected area using a variety of effector mechanisms. Aside from these established immune defense functions, neutrophils are emerging as one of the key tumor-infiltrating immune cells that influence cancer progression and metastasis. Neutrophil recruitment to the tumor microenvironment (TME) is mediated by multiple mediators including cytokines, chemokines, lipids, and growth factors that are secreted from cancer cells and cancer-associated stromal cells. However, the molecular mechanisms that underlie the expression and secretion of the different mediators from cancer cells and how neutrophils integrate these signals to reach and invade tumors remain unclear. Here, we discuss the possible role of the epithelial to mesenchymal transition (EMT) program, which is a well-established promoter of malignant potential in cancer, in regulating the expression and secretion of these key mediators. We also summarize and review our current understanding of the machineries that potentially control the secretion of the mediators from cancer cells, including the exocytic trafficking pathways, secretory autophagy, and extracellular vesicle-mediated secretion. We further reflect on possible mechanisms by which different mediators collaborate by integrating their signaling network, and particularly focus on TGF-β, a cytokine that is highly expressed in invasive tumors, and CXCR2 ligands, which are crucial neutrophil recruiting chemokines. Finally, we highlight gaps in the field and the need to expand current knowledge of the secretory machineries and cross-talks among mediators to develop novel neutrophil targeting strategies as effective therapeutic options in the treatment of cancer.

Identification and Validation of a Nine-Gene Amino Acid Metabolism-Related Risk Signature in HCC

Background: Hepatocellular carcinoma (HCC) is the world’s second most deadly cancer, and metabolic reprogramming is its distinguishing feature. Among metabolite profiling, variation in amino acid metabolism supports tumor proliferation and metastasis to the most extent, yet a systematic study on the role of amino acid metabolism-related genes in HCC is still lacking. An effective amino acid metabolism-related prediction signature is urgently needed to assess the prognosis of HCC patients for individualized treatment.

Materials and Methods: RNA-seq data of HCC from the TCGA-LIHC and GSE14520 (GPL3921) datasets were defined as the training set and validation set, respectively. Amino acid metabolic genes were extracted from the Molecular Signature Database. Univariate Cox and LASSO regression analyses were performed to build a predictive risk signature. K-M curves, ROC curves, and univariate and multivariate Cox regression were conducted to evaluate the predictive value of this risk signature. Functional enrichment was analyzed by GSEA and CIBERSORTx software.

Results: A nine-gene amino acid metabolism-related risk signature including B3GAT3, B4GALT2, CYB5R3, GNPDA1, GOT2, HEXB, HMGCS2, PLOD2, and SEPHS1 was constructed to predict the overall survival (OS) of HCC patients. Patients were separated into high-risk and low-risk groups based on risk scores and low-risk patients had lower risk scores and longer survival time. Univariate and multivariate Cox regression verified that this signature was an independent risk factor for HCC. ROC curves showed that this risk signature can effectively predict the 1-, 2-, 3- and 5-year survival times of patients with HCC. Additionally, prognostic nomograms were established based on the training set and validation set. These genes were closely correlated with the immune regulation.

Conclusion: Our study identified a nine-gene amino acid metabolism-related risk signature and built predictive nomograms for OS in HCC. These findings will help us to personalize the treatment of liver cancer patients.

Regulatory T cells promote innate inflammation after skin barrier breach via TGF-β activation

Regulatory T cells (T_regs) use multiple mechanisms to attenuate inflammation and prevent autoimmunity. T_regs residing in peripheral (i.e., nonlymphoid) tissues have specialized functions; specifically, skin T_regs promote wound healing, suppress dermal fibrosis, facilitate epidermal regeneration, and augment hair follicle cycling. Here, we demonstrated that skin T_regs were transcriptionally attuned to interact with their tissue environment through increased expression of integrin and TGF-β pathway genes that influence epithelial cell biology. We identified a molecular pathway where skin T_regs license keratinocytes to promote innate inflammation after skin barrier breach. Using a single-cell discovery approach, we identified preferential expression of the integrin αvβ8 on skin T_regs Upon skin injury, T_regs used this integrin to activate latent TGF-β, which acted directly on epithelial cells to promote CXCL5 production and neutrophil recruitment. Induction of this circuit delayed epidermal regeneration but provided protection from Staphylococcus aureus infection across a compromised barrier. Thus, αvβ8-expressing T_regs in the skin, somewhat paradoxical to their canonical immunosuppressive functions, facilitated inflammation acutely after loss of barrier integrity to promote host defense against infection.

Inflammation and tumor progression: signaling pathways and targeted intervention

Cancer development and its response to therapy are regulated by inflammation, which either promotes or suppresses tumor progression, potentially displaying opposing effects on therapeutic outcomes. Chronic inflammation facilitates tumor progression and treatment resistance, whereas induction of acute inflammatory reactions often stimulates the maturation of dendritic cells (DCs) and antigen presentation, leading to anti-tumor immune responses. In addition, multiple signaling pathways, such as nuclear factor kappa B (NF-kB), Janus kinase/signal transducers and activators of transcription (JAK-STAT), toll-like receptor (TLR) pathways, cGAS/STING, and mitogen-activated protein kinase (MAPK); inflammatory factors, including cytokines (e.g., interleukin (IL), interferon (IFN), and tumor necrosis factor (TNF)-α), chemokines (e.g., C-C motif chemokine ligands (CCLs) and C-X-C motif chemokine ligands (CXCLs)), growth factors (e.g., vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β), and inflammasome; as well as inflammatory metabolites including prostaglandins, leukotrienes, thromboxane, and specialized proresolving mediators (SPM), have been identified as pivotal regulators of the initiation and resolution of inflammation. Nowadays, local irradiation, recombinant cytokines, neutralizing antibodies, small-molecule inhibitors, DC vaccines, oncolytic viruses, TLR agonists, and SPM have been developed to specifically modulate inflammation in cancer therapy, with some of these factors already undergoing clinical trials. Herein, we discuss the initiation and resolution of inflammation, the crosstalk between tumor development and inflammatory processes. We also highlight potential targets for harnessing inflammation in the treatment of cancer.

Tumor-derived lactate inhibit the efficacy of lenvatinib through regulating PD-L1 expression on neutrophil in hepatocellular carcinoma

BACKGROUND

Neutrophils play a controversial role in tumor development. The function of programmed cell death-1 ligand (PD-L1⁺) neutrophils, however, may inhibit the cytotoxicity of anti-tumor immunity. In this study, we elucidate the stimulators of PD-L1⁺ neutrophils in tumor microenvironment (TME) and explore the optimal combination to enhance the effect of lenvatinib by inhibiting PD-L1⁺ neutrophils in hepatocellular carcinoma.

METHODS

Neutrophil infiltration after lenvatinib treatment was examined with RNA sequencing and multicolor flow cytometry analysis in patient samples, subcutaneous and orthotopic mouse models. Neutrophils and T cells were isolated from peripheral blood and tumor tissues and purified with magnetic beads for cytotoxicity assay. Metabolites and cytokines were detected by a biochemical analyzer manufactured by Yellow Springs Instrument (YSI) and proteome profiler cytokines array. In vitro screening of pathway inhibitors was used to identify possible candidates that could reduce PD-L1⁺ neutrophil infiltration. Further in vivo assays were used for verification.

RESULTS

Lenvatinib increased neutrophil recruitment by inducing CXCL2 and CXCL5 secretion in TME. After entering TME, neutrophils polarized toward N2 phenotype. PD-L1 expression was simultaneously upregulated. Thus, lenvatinib efficacy on tumor cells hindered. The increasing PD-L1⁺ neutrophils positively corelated with a suppressive T cell phenotype. Further investigation indicated that JAK/STAT1 pathway activated by immune-cell-derived interferon γ and MCT1/NF-kB/COX-2 pathway activated by high concentrations of tumor-derived lactate could induce PD-L1⁺ neutrophils. The latter could be significantly inhibited by COX-2 inhibitor celecoxib. Further in vivo assays verified that Celecoxib decreased the survival of lactate-stimulated PD-L1⁺ neutrophil and promoted the antitumor effect of lenvatinib.

CONCLUSIONS

PD-L1⁺ neutrophils decrease T cell cytotoxicity. Tumor-derived lactate induces PD-L1 expression on neutrophils via MCT1/NF-κB/COX-2 pathway. Thus, COX-2 inhibitor could reduce PD-L1⁺ neutrophil and restore T cell cytotoxicity. This may provide a potent addition to lenvatinib.