Regulatory mechanisms of interleukin-8 production induced by tumour necrosis factor-α in human hepatocellular carcinoma cells

Prognostic signature for hepatocellular carcinoma based on 4 pyroptosis-related genes

BACKGROUND

Hepatocellular carcinoma (HCC) is a cancer with a poor prognosis. Many recent studies have suggested that pyroptosis is important in tumour progression. However, the role of pyroptosis-related genes (PRGs) in HCC remains unclear.

MATERIALS AND METHODS

We identified differentially expressed PRGs in tumours versus normal tissues. Through univariate, LASSO, and multivariate Cox regression analyses, a prognostic PRG signature was established. The signature effectiveness was evaluated by time-dependent receiver operating characteristic (t-ROC) curve and Kaplan-Meier (KM) survival analysis. The signature was validated in the ICGC (LIRI-JP) cohort. In addition, single-sample gene enrichment analysis (ssGSEA) showed the infiltration of major immune cell types and the activity of common immune pathways in different subgroups.

RESULTS

Twenty-nine pyroptosis-related DEGs from The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) dataset were detected, and four genes (CTSV, CXCL8, MKI67 and PRF1) among them were selected to construct a prognostic signature. Then, the patients were divided into high- and low-risk groups. The pyroptosis-related signature was significantly associated with overall survival (OS). In addition, the patients in the high-risk group had lower levels of immune infiltration.

CONCLUSION

The prognostic signature for HCC based on 4 pyroptosis-related genes has reliable prognostic and predictive value for HCC patients.

Identification of immune infiltration-related genes as prognostic indicators for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has a high degree of malignancy and a poor prognosis. Immune infiltration-related genes have shown good predictive value in the prognosis of many solid tumours. In this study, we established and verified prognostic biomarkers consisting of immune infiltration-related genes in HCC. Gene expression data and clinical data were downloaded from The Cancer Genome Atlas (TCGA) database. Differential gene expression analysis, univariate Cox regression analysis and the least absolute shrinkage and selection operator (LASSO) regression algorithm were used to screen prognostic immune infiltration-related genes and to construct a risk scoring model. Kaplan-Meier (KM) survival plots and receiver operating characteristic (ROC) curve analysis were used to evaluate the prognostic performance of the risk scoring model in the TCGA-HCC cohort. In addition, a nomogram model with a risk score was established, and its predictive performance was verified by ROC analysis and calibration plot analysis in the TCGA-HCC cohort. Gene set enrichment analysis (GSEA) identified pathways and biological processes that may be enriched in the high-risk group. Finally, immune infiltration analysis was used to explore the characteristics of the tumour microenvironment related to the risk score. We identified 17 immune infiltration-related genes with prognostic value and constructed a risk scoring model. ROC analysis showed that the risk scoring model can accurately predict the 1-year, 3-year, and 5-year overall survival (OS) of HCC patients in the TCGA-HCC cohort. KM analysis showed that the OS of the high-risk group was significantly lower than that of the low-risk group (P < 0.001). The nomogram model effectively predicted the OS of HCC patients in the TCGA-HCC cohort. GSEA indicated that the immune infiltration-related genes may be involved in biological processes such as amino acid and lipid metabolism, matrisome and small molecule transportation, immune system regulation, and hepatitis virus infection. Immune infiltration analysis showed that the level of immune cell infiltration in the high-risk group was low, and the risk score was negatively correlated with infiltrating immune cells. Our prognostic model based on immune infiltration-related genes in HCC could help the prognostic assessment of HCC patients and provide potential targets for HCC inhibition.

Gene knockdown of CCR3 reduces eosinophilic inflammation and the Th2 immune response by inhibiting the PI3K/AKT pathway in allergic rhinitis mice

The CCR3 gene plays a critical role in allergic airway inflammation, such as allergic rhinitis (AR), and there is an inflammatory signal link between the nasal cavity and the CCR3 gene in bone marrow. However, the effects of the CCR3 gene in bone marrow cells on AR are not clear. The present study investigated the roles and underlying mechanisms of the bone marrow CCR3 gene in AR mice. Conditional knockout of the bone marrow CCR3 gene (CKO) in mice was generated using the Cre-LoxP recombination system, and offspring genotypes were identified using polymerase chain reaction (PCR). An ovalbumin-induced AR model was established in CKO and wild-type mice to measure eosinophilic inflammation and the Th2 immune response. The following mechanisms were explored using a specific PI3K/AKT pathway inhibitor (Ly294002). We successfully constructed and bred homozygous CKO mice and confirmed a significant increase in CCR3 expression and PI3K/AKT pathway activity in AR mice. Deficiency of the bone marrow CCR3 gene caused a remarkable reduction of CCR3 expression and the PI3K/AKT signaling pathway activity, inhibited histopathological lesions and eosinophil infiltration of the nasal cavity, and reduced the production of Th2 cytokines in serum, which led to the remission of allergic symptoms in AR mice. Ly294002 treatment also decreased these inflammatory indexes in a concentration-dependent manner and blocked inflammatory signals from CCR3, but it did not affect the high expression of CCR3 in AR mice. Collectively, our results suggest that conditional knockout of the bone marrow CCR3 gene can reduce eosinophilic inflammation and the Th2 immune response, which may be due to inhibition of the PI3K/AKT pathway.

Up-regulation of CXCL8 expression is associated with a poor prognosis and enhances tumor cell malignant behaviors in liver cancer

CXCL8, a member of CXC chemokines, was constitutively expressed in many types of human cancers, and its overexpression has been shown to play a critical role in promoting tumorigenesis. The purpose of the present study was to determine CXCL8 expression in a commercial human liver tissue microarray, and elucidate the effects and underlying mechanisms by which CXCL8 is involved in the malignant progression of human liver cancer. Our data showed that high level expression of CXCL8 in tissues with liver cancer was identified as compared with non-cancer tissues, and its up-regulation was closely associated with clinical stage and tumor infiltration. In vitro, exogenous CXCL8 at concentrations of 10, 20 or 40 ng/ml obviously stimulated the proliferation abilities of HepG2 cells. Coupled with this, 10, 20 or 40 ng/ml of exogenous CXCL8 also triggered a significant elevation in HepG2 cells migration. Additionally, overexpression of CXCL8 in HepG2 cells also resulted in increased cell proliferation and migration capacities. Finally, Western blotting analysis showed that overexpression of CXCL8 increased the expression of ERK, p-ERK and survivin, decreased the expression of caspase-3 and BAX at protein level.

Phase IB study of sorafenib and evofosfamide in patients with advanced hepatocellular and renal cell carcinomas (NCCTG N1135, Alliance)

Background Sorafenib (Sor) remains a first-line option for hepatocellular carcinoma (HCC) or refractory renal cell carcinomas (RCC). PLC/PRF/5 HCC model showed upregulation of hypoxia with enhanced efficacy when Sor is combined with hypoxia-activated prodrug evofosfamide (Evo). Methods This phase IB 3 + 3 design investigated 3 Evo dose levels (240, 340, 480 mg/m² on days 8, 15, 22), combined with Sor 200 mg orally twice daily (po bid) on days 1-28 of a 28-day cycle. Primary objectives included determining maximum tolerated dose (MTD) and recommended phase II dose (RP2D) of Sor + Evo. Results Eighteen patients were enrolled (median age 62.5 years; 17 male /1 female; 12 HCC/6 RCC) across three dose levels (DL0: Sor 200 mg bid/Evo 240 mg/m² [n = 6], DL1:Sor 200 mg bid/Evo 480 mg/m² [n = 5], DL1a: Sor 200 mg bid/Evo 340 mg/m² [n = 7]). Two dose-limiting toxicities (DLTs) were reported with Evo 480 mg/m² (grade 3 mucositis, grade 4 hepatic failure). Grade 3 rash DLT was observed in one patient at Evo 240 mg/m². No DLTs were observed at Evo 340 mg/m². MTD and RP2D were established as Sor 200 mg/Evo 340 mg/m² and Sor 200/Evo 240 mg/m², respectively. The most common treatment-related adverse events included fatigue, hand-foot syndrome, hypertension, and nausea/vomiting. Two partial responses were observed, one each at DL0 and DL1a.; disease control rate was 55%. Conclusions RP2D was established as sorafenib 200 mg bid + Evo 240 mg/m². While preliminary anti-tumor activity was observed, future development must account for advances in immunotherapy in HCC/RCC.

Integrin αVβ5/Akt/Sp1 pathway participates in matrix stiffness-mediated effects on VEGFR2 upregulation in vascular endothelial cells

Our previous study has validated that higher matrix stiffness obviously improves vascular endothelial growth factor (VEGF) expression in HCC cells, highlighting a linkage between matrix stiffness and HCC angiogenesis. However, the effects of matrix stiffness on vascular endothelial cells in HCC and its underlying mechanism remain largely uncharacterized. Here we further analyzed the expression of vascular endothelial growth factor receptor 2 (VEGFR2) in human umbilical vein endothelial cells (HUVECs) grown on different stiffness substrates and explored its regulatory mechanism for better understanding matrix stiffness-regulated angiogenesis in HCC. Our results revealed that increased matrix stiffness significantly upregulated the expression of VEGFR2 in HUVECs, and the expression level of VEGFR2 was positively correlated with the expression levels of COL1 and lysyl oxidase in human HCC tissues and rat HCC tissue, moreover VEGFR2 and CD34 were co-localized at blood vessel of HCC tissues, indicating an obvious regulation role of matrix stiffness in VEGFR2 expression. Simultaneously, increased matrix stiffness also elevated the phosphorylation level of Akt and the expressions of integrin αV/β5 and nuclear Sp1 in HUVECs. Inhibition of integrin αVβ5 remarkably reversed the expression of VEGFR2 and phosphorylation level of Akt in HUVECs grown on higher stiffness substrate. Except that, PI3K inhibitor also suppressed the phosphorylation level of Akt and the expressions of VEGFR2 and nuclear Sp1 evidently. Taken together, higher matrix stiffness increased VEGFR2 expression in HUVECs, and integrin αVβ5/Akt/Sp1 pathway participated in stiffness-mediated effects on VEGFR2 upregulation. This study combining with our previous report discloses a new paradigm in which higher matrix stiffness as an initiator drives HCC angiogenesis via upregulating both VEGFR2 expression in vascular endothelial cells and VEGF expression in HCC cells.

Regulatory B Cells and Their Cytokine Profile in HCV-Related Hepatocellular Carcinoma: Association with Regulatory T Cells and Disease Progression

Although regulatory B cells (Bregs) have been proven to play a suppressive role in autoimmune diseases, infections and different tumors, little is known regarding hepatocellular carcinoma (HCC), especially in hepatitis C-related settings. Herein, we analyzed the frequency of circulating Bregs, serum levels of IL-10, IL-35 and B-cell activating factor (BAFF) and investigated their association with regulatory T cells (Tregs) and disease progression in HCV-related HCC. For comparative purposes, four groups were enrolled; chronic HCV (CHC group, n = 35), HCV-related liver cirrhosis (HCV-LC group, n = 35), HCV-related HCC (HCV-HCC group, n = 60) and an apparently healthy control (Control-group, n = 20). HCC diagnosis and staging were in concordance with the Barcelona Clinic Liver Cancer (BCLC) staging system. Analysis of the percentage of Breg cells and peripheral lymphocyte subsets (Treg) was performed by flow cytometry. Serum cytokine levels of IL-10, IL-35 and B-cell activating factor (BAFF) were measured by ELISA. The frequency of Bregs was significantly higher in the HCV-HCC group compared to the other groups and controls. A significant increase was noted in late-HCC versus those in the early stages. The frequency of Bregs was positively correlated with Tregs, serum IL-10, IL-35 and BAFF. In conclusion, Peripheral Bregs were positively correlated with the frequency of Tregs, IL-10, IL-35 and BAFF, and may be associated with HCV-related HCC progression.

Inflammatory response in repeat breeder buffaloes

The aim of this study was to investigate the repeat breeding condition in Italian Mediterranean buffaloes that failed to conceive after at least 300 days in milk. The trial was carried out on 40 pluriparous Italian Mediterranean buffaloes with more than 300 days in milk. All the animals underwent ultrasound examination to assess endometrial thickness and oestrus synchronization by the Ovsynch-TAI Program. On the day of oestrus, blood samples were collected for the haemocytometric cell count and biochemical assay, and the animals were slaughtered in a local abattoir. A post-mortem uterine flushing was performed using sterile saline for microbiological analyses. Furthermore, uterine biopsies were carried out for histopathological assessment. Finally, endometrial samples were used for real-time PCR (RT-PCR) analysis to evaluate the expression of genes involved in innate immune recognition of pathogens and the inflammatory response, such as Toll-like receptor (TLR)1, TLR8, interleukin (IL)-1β, IL-6, IL-8, COL4A2, connective tissue growth factor (CTGF), and cysteine-rich angiogenic inducer 61 (CYR61). Statistical analysis was performed by one-way ANOVA. Based on the infiltration of lymphocytes and plasma cells or endometrial gland, lymphatic, and blood vessel ectasia recorded in the histopathological examination, the animals were classified into three groups: healthy (H Group; n = 5), moderate endometritis (M Group; n = 25), and severe endometritis (S Group; n = 10). A significantly greater (P < 0.01) endometrial thickness was recorded in the S Group compared to that in the H and M Group (1.07 ± 0.03 vs. 0.70 ± 0.07 and 0.81 ± 0.04 cm in the S, H, and M Group, respectively). The white blood cell count was lower in the H Group compared to that in the M and S Group (6.3 ± 0.6 vs. 9.3 ± 0.4 and 10.5 ± 0.5 in the H, M, and S Group, respectively). To perform RT-PCR analysis, five animals from groups M and S were randomly selected in order to have balanced results. A higher (P < 0.01) expression of TLR1, together with a lower expression of COL4A2, IL-1β, IL-6, IL-8, and CYR61, was recorded in the H Group, compared to both the M and S Groups. In conclusion, about 90% of repeat breeder buffaloes show moderate or severe endometritis, associated with an altered histopathological endometrial profile and altered mRNA expression of pro-inflammatory and fibrotic factors.

A 2,3-diphenylpyrido[1,2-a] pyrimidin-4-one derivative inhibits specific angiogenic factors induced by TNF-α

Low-grade chronic inflammation is a key process of angiogenesis in tumour progression. We investigated whether a synthetic analogue of apigenin, the 2-(3,4-dimethoxyphenyl)-3-phenyl-4H-pyrido[1,2-a] pyrimidin-4-one (called DB103), interfered with the mechanisms involved in the angiogenic process induced by the inflammatory cytokine tumour necrosis factor (TNFα). In endothelial cells, DB103 but not apigenin reduced the TNFα-induced oxidative stress. DB103 inhibited the activation of ERK1/2 but not JNK, p38 and Akt kinases, while apigenin was not so selective because it inhibited essentially all examined kinases. Similarly, apigenin inhibited the TNFα-induced transcription factors CREB, STAT3, STAT5 and NF-κB, while DB103 acted only on NF-κB. DB103 inhibited the induced-release of angiogenic factors such as monocyte chemotactic protein-1, interleukin-6 (IL-6) and angiopoietin-2 but not IL-8, while apigenin reduced the IL-6 and IL-8 release. DB103 revealed a better ability than apigenin to modulate proangiogenic responses induced by an inflammatory microenvironment.

High interleukin-8 and/or extracellular signal-regulated kinase 2 expression predicts poor prognosis in patients with hepatocellular carcinoma

Interleukin (IL)-8 and extracellular signal-regulated kinase (ERK) 2 play key roles in tumor progression, but the relationship between IL-8 and/or ERK2 expression in hepatocellular carcinoma (HCC) tissues and postoperative recurrence or survival is unclear. The expression levels of IL-8 and ERK2 in both HCC tissues and non-tumor liver tissues were analyzed using the Oncomine™ database and immunohistochemistry assay. Reverse transcription-quantitative PCR was then used to evaluate the expression levels of IL-8 and ERK2 in the tumor tissues of 67 patients with HCC undergoing radical hepatectomy. Pearson's correlation, Kaplan-Meier, Cox univariate and multivariate survival analyses were utilized to determine the correlation between IL-8 and ERK2 expression in HCC tissues, and their potential prognostic significance. As indicated by the data from the Oncomine™ database, and the patient samples, IL-8 and ERK2 were expressed at significantly higher levels in HCC tissues than in non-tumor liver tissues (P<0.05). The rates of high IL-8 and ERK2 expression in HCC tissues were 43.28 (29/67) and 34.33% (23/67), respectively, and the IL-8 and ERK2 expression levels were positively correlated (r=0.764; P<0.001). Both ERK2 expression and IL-8/ERK2 co-expression were significantly associated with tumor size and differentiation (P<0.05). Additionally, high expression levels of IL-8, ERK2 and IL-8/ERK2 co-expression were all significantly associated with poor overall survival (OS; P<0.05) and disease-free survival (DFS; P<0.05). Multivariate Cox regression analysis also showed that high expression levels of IL-8, ERK2, and IL-8 and ERK2 were independent prognostic factors for OS and DFS (P<0.05). The results of the present study indicate a significant increase in the risk of recurrence and mortality in HCC patients with high expression levels of IL-8 and/or ERK2, compared with patients with low expression. Therefore, IL-8 and ERK2 may be predictors of postoperative prognosis in patients with HCC.

N‑acetyl cysteine protects HUVECs against lipopolysaccharide‑mediated inflammatory reaction by blocking the NF‑κB signaling pathway

The purpose of the study was to explore the potential protective effects of N‑acetylcysteine (NAC) against lipopolysaccharide (LPS)‑induced inflammatory injury to human umbilical vein endothelial cells (HUVECs). It was also assessed whether the underlying mechanism of this protective effect is mediated via suppression of the nuclear factor‑kappa B (NF‑κB) signaling pathway. Cell viability of HUVECs treated with different concentrations of NAC was assessed using Cell Counting Kit‑8 (CCK‑8) assay. The mRNA expression of inflammatory factors [interleukin‑8 (IL‑8), tumor necrosis factor α (TNF‑α), inducible nitric oxide synthase (iNOS), and intercellular cell adhesive molecule 1 (ICAM‑1)] were assessed using real time semi‑quantitative polymerase chain reaction. Protein expression levels of TNF‑α and IL‑8 were assessed using enzyme‑linked immunosorbent assay. Protein expression levels of ICAM‑1 and the NF‑κB signaling pathway were assessed using western blotting. Nitric reductase method was used to quantify nitric oxide (NO) and iNOS. LPS stimulated the production of TNF‑α, IL‑8, NO, and ICAM‑1 by HUVECs. Moreover, LPS induced activation of the NF‑κB signaling pathway and increased the protein expression of phosphorylated p65. However, pretreatment of HUVECs with NAC significantly attenuated the increase in the expression of inflammatory factors and the level of phosphorylated p65; this indicated that NAC prevented the activation of the NF‑κB signaling pathway. The present findings indicated that NAC protects HUVECs against LPS‑mediated inflammatory reaction and alleviates inflammation. The underlying mechanism is related to the NF‑κB signaling pathway. NAC appears to be a promising agent for prevention and treatment of inflammatory diseases.

High TNF-α and/or p38MAPK expression predicts a favourable prognosis in patients with T1N0M0 hepatocellular carcinoma: An immunohistochemical study

Tumour necrosis factor α (TNF-α) and p38 mitogen-activated protein kinase (p38MAPK) serve an important role in regulating tumour cell apoptosis. However, a limited number of studies have investigated the predictive value of both TNF-α and p38MAPK in hepatocellular carcinoma (HCC). An integrated bioinformatics analysis was initially performed using two datasets available from the Oncomine™ database to determine the association between TNF-α and/or p38MAPK expression and prognosis of patients with HCC. Subsequently, TNF-α and p38MAPK expression in tissue samples from 83 patients with HCC classified as T1N0M0, using the Tumour-Node-Metastasis (TNM) staging system, was investigated using immunohistochemistry. The associations between clinicopathological characteristics and different TNF-α and p38MAPK expression levels in HCC were investigated using the χ2 test. Kaplan-Meier and Cox univariate/multivariate survival analyses were performed to explore the predictive significance of TNF-α and/or p38MAPK expression in patients with HCC. Using the Oncomine™ database, it was revealed that TNF-α and/or p38MAPK expression was not significantly associated with overall survival (OS) or disease-free survival (DFS) rates; however, TNF-α and p38MAPK expression levels were positively associated (P<0.05), and high p38MAPK expression was significantly associated with low aspartate aminotransferase levels (P<0.05). Compared with low expression levels of TNF-α and p38MAPK together, high expression of TNF-α alone, p38MAPK alone and TNF-α and p38MAPK together were significantly associated with improved OS and DFS rates (P<0.05). Additionally, multivariate Cox regression models suggested that high expression levels of TNF-α alone, p38MAPK alone, or TNF-α and p38MAPK together in the HCC microenvironment were independent predictive factors for OS and DFS rates (P<0.05). Patients with T1N0M0 HCC with high TNF-α and/or p38MAPK expression had a significantly lower risk of recurrence and mortality compared with patients with low TNF-α and p38MAPK expression. Consequently, TNF-α and p38MAPK could serve as predictive biomarkers or potential therapeutic targets for T1N0M0 HCC treatment.

TM6SF2 E167K Variant Overexpression Promotes Expression of Inflammatory Cytokines in the HCC Cell Line HEPA 1-6

Background and Aims: Accumulated evidence has shown that chronic liver inflammation is one of the main risks of hepatocellular carcinoma (HCC), and E167K variant of the transmembrane 6 superfamily member 2 (TM6SF2) plays an important role in the progression of chronic liver diseases and HCC. The aim of this study was to explore effects of the TM6SF2 E167K variant on expression of the inflammatory cytokines TNF-α, IL-2, IL-6 and IL-8 in the HCC cell line HEPA 1-6. Methods: HEPA 1-6 cells were infected with lentivirus containing either the TM6SF2 E167K variant or TM6SF2 wild-type, or control plasmids. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were conducted to analyze the expression of the inflammatory cytokines TNF-α, IL-2, IL-6 and IL-8. A t-test was used for statistical analysis. Results: Compared with the control group and TM6SF2 overexpression group, the relative expression of IL-2 and IL-6 mRNAs were significantly elevated in the TM6SF2 E167K overexpression group (p < 0.05). The relative mRNA expression of IL-8 in the TM6SF2 and TM6SF2 E167K overexpression groups were increased compared to the control group (p < 0.05). No obvious differences were observed for the expression of TNF-α in each group. The expression of TNF-α, IL-2, IL-6 and IL-8 that was tested by western blotting showed the same trends as the qRT-PCR results. Conclusions: In conclusion, the E167K variant of the TM6SF2 gene could promote the expression of inflammatory cytokines IL-2 and IL-6 in HEPA 1-6 cells, suggesting that the TM6SF2 E167K variant may accelerate the progression of HCC.

Synergistic effect of carbon nuclei and polyaromatic hydrocarbons on respiratory and immune responses

Particulate matter with aerodynamic diameter ≤2.5 μm (PM_2.5 ) is generally composed of carbon nuclei associated with various organic carbons, metals, ions and biological materials. Among these components, polyaromatic hydrocarbons (PAHs) such as benzo(a)pyrene (BaP) and quinones have detrimental effects on airway epithelial cells and immunodisrupting effects, which leads to the exacerbation of respiratory allergies. The effects of PAHs and the carbon nuclei, separately as well as in combination, remain to be established. We investigated the effects of BaP, 9,10-phenanthroquinone (9,10-PQ), and 1,2-napthoquinone (1,2-NQ) and their combined effects with heated diesel exhaust particle (H-DEP) as carbon nuclei of typical PM_2.5 . We exposed human airway epithelial cells (BEAS-2B), murine bone marrow-derived antigen-presenting cells (APCs), and murine splenocytes to BaP, 9,10-PQ, or 1,2-NQ in the presence and absence of H-DEP. Several important inflammatory cytokines and cell surface molecules were measured. PAHs alone did not have apparent cytotoxic effects on BEAS-2B, whereas combined exposure with H-DEP induced noticeable detrimental effects which mainly reflected the action of H-DEP itself. BaP increased CD86 expression as an APC surface molecule regardless of the presence or absence of H-DEP. None of the BaP, 9,10-PQ, or 1,2-NQ exposure alone or their combined exposure with H-DEP resulted in any significant activation of splenocytes. These results suggest that PAHs and carbon nuclei show additive effects, and that BaP with the carbon nuclei may contribute to exacerbations of allergic respiratory diseases including asthma by PM_2.5 , especially via antigen-presenting cell activation.

HOXB7 promotes tumor progression via bFGF-induced activation of MAPK/ERK pathway and indicated poor prognosis in hepatocellular carcinoma

The homeobox-containing gene HOXB7 plays an important role in the pathogenesis and progression of many cancers, yet its role in hepatocellular carcinoma (HCC) remains unclear. This study comprehensively analyzed the expression and clinical significance of HOXB7 in HCC and explored its potential mechanism in tumor progression. We found HOXB7 was highly expressed in HCC cell lines with highly metastatic potential and cancerous tissues from patients with tumor recurrence. The abilities of proliferation, migration, and invasion were notably decreased by depletion of HOXB7, and were enhanced by its enforced expression in vitro. HOXB7 expression was positively correlated with tumor progression and lung metastasis in vivo. The gene microarray data implied that HOXB7 affects biological functions of HCC cells through MAPK/ERK pathway activation. Further study confirmed that the effect of HOXB7 in activating MAPK/ERK pathway via induction of basic fibroblast growth factor (bFGF) secretion, and the inhibition of bFGF secretion could abolish MAPK/ERK pathway activation after ectopic expression of HOXB7. Chromatin immunoprecipitation experiments and luciferase reporter assays confirmed that HOXB7 promoted bFGF secretion via binding its promoter directly. Furthermore, the clinical significance of HOXB7 expression was confirmed using tissue microarrays containing 394 HCC tissue specimens. Patients with high HOXB7 expression showed shorter survival times and higher recurrence rates, and HOXB7 was an independent indicator for survival and recurrence. Overall, HOXB7 promotes HCC cell proliferation, migration, and invasion through the bFGF-induced MAPK/ERK pathway activation. It might be a novel prognostic factor in HCC and a promising therapeutic target for tumor metastasis and recurrence.

Hepatoma cell functions modulated by NEK2 are associated with liver cancer progression

NEK2 (NIMA-related expressed kinase 2) is a serine/threonine centrosomal kinase that acts as a critical regulator of centrosome structure and function. Aberrant NEK2 activities lead to failure in regulating centrosome duplication. NEK2 overexpression promotes tumorigenesis and is associated with poor prognosis in several cancers. Increased NEK2 expression during the late pathological stage has been detected in the Oncomine liver dataset and hepatocellular carcinoma (HCC) specimens. Elevated NEK2 protein is associated with poor overall survival in patients with HCC. However, the precise roles and mechanisms of NEK2 in liver cancer progression remain largely unknown. An earlier functional study revealed that NEK2 mediates drug resistance (cisplatin or lipo-doxorubicin) via expression of an ABCC10 transporter. Active angiogenesis and metastasis underlie the rapid recurrence and poor survival of HCC. Results from the current study showed that NEK2 mediates tumor growth, metastasis and angiogenesis in vivo. NEK2-mediated drug resistance was blocked by a specific PI3K or AKT inhibitor. Moreover, NEK2 mediated liver cancer cell migration via pAKT/NF-κB signaling and matrix metalloproteinase (MMP) activation. Angiogenesis was induced via the same signaling pathway and IL-8 stimulation. Our findings collectively indicate that NEK2 modulates hepatoma cell functions, including growth, drug resistance, metastasis and angiogenesis via downstream genes activation.

Therapeutic targeting of replicative immortality

One of the hallmarks of malignant cell populations is the ability to undergo continuous proliferation. This property allows clonal lineages to acquire sequential aberrations that can fuel increasingly autonomous growth, invasiveness, and therapeutic resistance. Innate cellular mechanisms have evolved to regulate replicative potential as a hedge against malignant progression. When activated in the absence of normal terminal differentiation cues, these mechanisms can result in a state of persistent cytostasis. This state, termed "senescence," can be triggered by intrinsic cellular processes such as telomere dysfunction and oncogene expression, and by exogenous factors such as DNA damaging agents or oxidative environments. Despite differences in upstream signaling, senescence often involves convergent interdependent activation of tumor suppressors p53 and p16/pRB, but can be induced, albeit with reduced sensitivity, when these suppressors are compromised. Doses of conventional genotoxic drugs required to achieve cancer cell senescence are often much lower than doses required to achieve outright cell death. Additional therapies, such as those targeting cyclin dependent kinases or components of the PI3K signaling pathway, may induce senescence specifically in cancer cells by circumventing defects in tumor suppressor pathways or exploiting cancer cells' heightened requirements for telomerase. Such treatments sufficient to induce cancer cell senescence could provide increased patient survival with fewer and less severe side effects than conventional cytotoxic regimens. This positive aspect is countered by important caveats regarding senescence reversibility, genomic instability, and paracrine effects that may increase heterogeneity and adaptive resistance of surviving cancer cells. Nevertheless, agents that effectively disrupt replicative immortality will likely be valuable components of new combinatorial approaches to cancer therapy.

A multi-targeted approach to suppress tumor-promoting inflammation

Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes.

CXCR2-CXCL1 axis is correlated with neutrophil infiltration and predicts a poor prognosis in hepatocellular carcinoma

Background & aims

Inflammation is a hallmark of cancer, yet the mechanisms that regulate immune cell infiltration into tumors remain poorly characterized. This study attempted to characterize the composition, distribution, and prognostic value of CXCR2⁺ cells in hepatocellular carcinoma (HCC) and to examine the CXCR2 ligands that are responsible for local immune infiltration in different areas of HCC tumors.

Methods

Immunohistochemistry and immunofluorescene were used to identify CXCR2⁺ cells in HCC tissues. Kaplan–Meier analysis and Cox regression models were applied to estimate recurrence-free survival (RFS) and overall survival (OS) for 259 HCC patients. The expression levels of CXCR2 ligands (CXCL-1, −2, −5, and −8) were measured by real-time PCR and compared with local immune cell density. The combined prognostic value of the CXCR2–CXCL1 axis was further evaluated.

Results

In HCC tissues, CXCR2⁺ cells were mainly neutrophils that were enriched in the peri-tumoral stroma (PS) region. Kaplan–Meier survival analysis showed that increased CXCR2⁺_PS cells were associated with reduced RFS and OS (P = 0.015 for RFS; P = 0.002 for OS). Multivariate Cox proportional hazards analysis identified CXCR2⁺_PS cell density as an independent prognostic factor for OS (hazard ratio [HR] = 1.737, 95 % confidence interval [CI] = 1.167–2.585, P = 0.006). Furthermore, we detected a positive correlation between the density of CD15⁺ neutrophils and CXCL1 levels in both the peri-tumoral stroma and intra-tumoral regions. The combination of CXCR2 and CXCL1 expression levels represented a powerful predictor of a poor prognosis for patients with HCC.

Conclusions

Our data showed that the CXCR2⁺ cell density was an independent prognostic factor for predicting OS for HCC patients. The CXCR2–CXCL1 axis can regulate neutrophil infiltration into HCC tumor tissues and might represent a useful target for anti-HCC therapies.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-015-0247-1) contains supplementary material, which is available to authorized users.

Formylpeptide receptor 1 mediates the tumorigenicity of human hepatocellular carcinoma cells

G protein-coupled chemoattractant receptors (GPCRs) have been implicated in cancer progression. Formylpeptide receptor 1 (FPR1) was originally identified as a GPCR mediating anti-microbial host defense. However, the role of FPR1 in tumorigenesis remains poorly understood. The current study aims to investigate the potential of FPR1 to regulate human hepatoma growth and invasion. We found the FPR1 gene and protein expression in human intratumoral and peritumoral tissues of hepatocellular carcinoma (HCC) specimens and in human hepatoma cell lines. FPR1 activation mediated the migration, calcium mobilization and ERK-dependent IL-8 production by hepatic cancer cells. FPR1 knockdown substantially reduced the tumorigenicity of hepatoma cells in nude mice. Necrotic hepatic tumor cells released factor(s) that activated FPR1 in live tumor cells. Our results indicate a critical role of FPR1 in the progression of malignant human hepatic cancer. FPR1 thus may represent a molecular target for the development of novel anti-hepatoma therapeutics.

Challenges and future perspectives of T cell immunotherapy in cancer

Since the formulation of the tumour immunosurveillance theory, considerable focus has been on enhancing the effectiveness of host antitumour immunity, particularly with respect to T cells. A cancer evades or alters the host immune response by various ways to ensure its development and survival. These include modifications of the immune cell metabolism and T cell signalling. An inhibitory cytokine milieu in the tumour microenvironment also leads to immune suppression and tumour progression within a host. This review traces the development in the field and attempts to summarize the hurdles that the approach of adoptive T cell immunotherapy against cancer faces, and discusses the conditions that must be improved to allow effective eradication of cancer.

Chemokines and their receptors play important roles in the development of hepatocellular carcinoma

The chemokine system consists of four different subclasses with over 50 chemokines and 19 receptors. Their functions in the immune system have been well elucidated and research during the last decades unveils their new roles in hepatocellular carcinoma (HCC). The chemokines and their receptors in the microenvironment influence the development of HCC by several aspects including: inflammation, effects on immune cells, angiogenesis, and direct effects on HCC cells. Regarding these aspects, pre-clinical research by targeting the chemokine system has yielded promising data, and these findings bring us new clues in the chemokine-based therapies for HCC.

Rosiglitazone via PPARγ-dependent suppression of oxidative stress attenuates endothelial dysfunction in rats fed homocysteine thiolactone

To explore whether rosiglitazone (RSG), a selective peroxisome proliferator-activated receptor γ (PPARγ) agonist, exerts beneficial effects on endothelial dysfunction induced by homocysteine thiolactone (HTL) and to investigate the potential mechanisms. Incubation of cultured human umbilical vein endothelial cells with HTL (1 mM) for 24 hrs significantly reduced cell viabilities assayed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, as well as enhanced productions of reactive oxygen species, activation of nuclear factor kappa B, and increased intercellular cell adhesion molecule-1 secretion. Pre-treatment of cells with RSG (0.001–0.1 mM), pyrollidine dithiocarbamate (PDTC, 0.1 mM) or apocynin (0.1 mM) for 1 hr reversed these effects induced by HTL. Furthermore, co-incubation with GW9662 (0.01 mM) abolished the protective effects of RSG on HTL-treated cells. In ex vivo experiments, exposure of isolated aortic rings from. rats to HTL (1 mM) for 1 hr dramatically impaired acetylcholine-induced endothelium-dependent relaxation, reduced release of nitric oxide and activity of superoxide dismutase, and increased malondialdehyde content in aortic tissues. Preincubation of aortic rings with RSG (0.1, 0.3, 1 mM), PDTC or apocynin normalized the disorders induced by HTL. In vivo analysis indicated that administration of RSG (20 mg/kg/d) remarkably suppressed oxidative stress and prevented endothelial dysfunction in rats fed HTL (50 mg/kg/d) for 8 weeks. RSG improves endothelial functions in rats fed HTL, which is related to PPARγ-dependent suppression of oxidative stress.

G31P, CXCR1/2 inhibitor, with cisplatin inhibits the growth of mice hepatocellular carcinoma and mitigates high‑dose cisplatin-induced nephrotoxicity

Cisplatin (DDP), a cytotoxic antitumor drug, functions in a dose-dependent manner. However, the pursuit for high‑dose therapeutic effects leads to more serious side effects including kidney toxicity. Nephrotoxicity caused due to endothelial cell dysfunction and neutrophils infiltration in kidneys. Interleukin-8 (IL-8) is an ELR+ chemokine binds with CXCR1/2 receptors and its role is primarily in neutrophils recruitment and also involved in invasion, angiogenesis and metastasis of different solid tumors including liver cancer. G31P, a CXCR1/2 antagonist, binds with CXCR1/2 with high affinity, and acts as an anti-inflammatory and antitumor agent. In the present study, we examined the antitumor effects of G31P and DDP on mouse liver cancer cells, and the effects exerted by G31P on cisplatin-induced renal injury. In vitro, effects of the G31P and DDP regimen on H22 cell proliferation were investigated by MTT assay. In vivo BALB/c mice were inoculated subcutaneously with 1x106 H22 cells and treated after one week with a high single dose of DDP with and without G31P on alternative days until the experiment was terminated. On the 15th day the mice were sacrificed, dissected and kidney tissues were analyzed using H&E staining. Myeloperoxidase (MPO) activity was assessed and RT-PCR was performed to detect inflammatory cytokines. Solid tumors were weighed for tumor growth and performed pathological examination, immunohistochemistry and western blotting were performed to detect tissue-related protein expressions in tumor tissue. The tumor inhibitory rate of DDP, G31P and DDP+G31P groups was 38.40, 40.74 and 74.80%, respectively, and the general state of mice in the DDP+G31P group was significantly improved as compared to the DDP group. The results indicated that G31P with DDP significantly inhibited the proliferation while the growth of H22 cell carnimona in vitro and in vivo enhanced the efficacy of cisplatin in cancer treatment with reduced side effects on acute renal failure.

Berberine hydrochloride IL-8 dependently inhibits invasion and IL-8-independently promotes cell apoptosis in MDA-MB-231 cells

Breast cancer, the leading cause of cancer-related mortality worldwide in females, has high metastastic and recurrence rates. The aim of the present study was to evaluate the anti-metastatic and anticancer in situ effect of berberine hydrochloride (BER) in MDA-MB-231 cells. BER dose-dependently inhibited proliferation and the IL-8 secretion of MDA-MB-231 cells. Additional experiments revealed that the inactivation of PI3K, JAK2, NF-κB and AP-1 by BER contributed to the decreased IL-8 secretion. BER abrogated cell invasion induced by IL-8 accompanied with the downregulation of the gene expression of MMP-2, EGF, E-cadherin, bFGF and fibronectin. In addition, BER reduced cell motility but induced G2/M arrest and cell apoptosis in an IL-8‑independent manner. BER modulated multiple signaling pathway molecules involved in the regulation of cell apoptosis, including activation of p38 MAPK and JNK and deactivation of JAK2, p85 PI3K, Akt and NF-κB. The enhanced cell apoptosis induced by BER was eliminated by inhibitors of p38 MAPK and JNK but was strengthened by activator of p38 MAPK. Thus, BER inhibited cell metastasis partly through the IL-8 mediated pathway while it induced G2/M arrest and promoted cell apoptosis through the IL-8 independent pathway. Apoptosis induced by BER was mediated by crosstalks of various pathways including activation of p38 MAPK and JNK pathways and inactivation of Jak2/PI3K/NF-κB/AP-1 pathways. The results suggested that BER may be an efficient and safe drug candidate for treating highly metastatic breast cancer.

Candidate tumour suppressor CCDC19 regulates miR-184 direct targeting of C-Myc thereby suppressing cell growth in non-small cell lung cancers

We previously reported and revised the nasopharyngeal epithelium specific protein CCDC19 and identified it as a potential tumour suppressor in nasopharyngeal carcinoma. The purpose of this study was to investigate the involvement of CCDC19 in the pathogenesis of human non-small cell lung cancers (NSCLC). Down-regulated CCDC19 expression was observed in NSCLC tissues and cells compared to normal tissues. However, reduced protein expression did not correlate with the status of NSCLC progression. Instead, we observed that patients with lower CCDC19 expression had a shorter overall survival than did patients with higher CCDC19 expression. Lentiviral-mediated CCDC19 overexpression significantly suppressed cell proliferation and cell cycle transition from G1 to S and G2 phases in NSCLC cells. Knocking down CCDC19 expression significantly restored the ability of cell growth in CCDC19 overexpressing NSCLC cells. Mechanistically CCDC19 functions as a potential tumour suppressor by stimulating miR-184 suppression of C-Myc thus blocking cell growth mediated by the PI3K/AKT/C-Jun pathway. Our studies are the first to demonstrate that reduced expression of CCDC19 is an unfavourable factor in NSCLC.

Novel PI3K and mTOR Inhibitor NVP-BEZ235 Radiosensitizes Breast Cancer Cell Lines under Normoxic and Hypoxic Conditions

In the present study, we assessed, if the novel dual phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibitor NVP-BEZ235 radiosensitizes triple negative (TN) MDA-MB-231 and estrogen receptor (ER) positive MCF-7 cells to ionizing radiation under various oxygen conditions, simulating different microenvironments as occurring in the majority of breast cancers (BCs). Irradiation (IR) of BC cells cultivated in hypoxic conditions revealed increased radioresistance compared to normoxic controls. Treatment with NVP-BEZ235 completely circumvented this hypoxia-induced effects and radiosensitized normoxic, reoxygenated, and hypoxic cells to similar extents. Furthermore, NVP-BEZ235 treatment suppressed HIF-1α expression and PI3K/mTOR signaling, induced autophagy, and caused protracted DNA damage repair in both cell lines in all tested oxygen conditions. Moreover, after incubation with NVP-BEZ235, MCF-7 cells revealed depletion of phospho-AKT and considerable signs of apoptosis, which were significantly enhanced by radiation. Our findings clearly demonstrate that NVP-BEZ235 has a clinical relevant potential as a radiosensitizer in BC treatment.

The role of EGF-EGFR signalling pathway in hepatocellular carcinoma inflammatory microenvironment

Epidermal growth factor (EGF) and their receptor (EGFR) play an important role in the development of cancer proliferation, and metastasis, although the mechanism remains unclear. The present study aimed at investigating the role of EGF-EGFR signalling pathway in the development of human hepatocellular carcinoma (HCC) inflammatory environment. Gene profiles of inflammatory cytokines from HCC were measured. Cell bio-behaviours of HCC with low or high metastasis were detected by the live cell monitoring system. Cell proliferation was measured by CCK8. The protein level of CXCL5 and CXCL8 was measured by ELISA. The phosphorylation of PI3K, ERK, MAPK was measured by western blot. EGF significantly induced cell proliferation in HepG2 cells, but not in HCCLM3 cells. EGF prompted the cell movement in both HepG2 and HCCLM3 and regulated the production of CXCL5 and CXCL8 from HCC, which were inhibited by EGFR inhibitor, Erk inhibitor (U0126), or PI3K inhibitors (BEZ-235 and SHBM1009). HCC proliferation, metastasis and production of inflammatory cytokines were regulated via EGF-EGFR signal pathways. CXCL5 could interact with CXCL8, possibly by CXCR2 or the cross-talk between CXCR2 and EGFR. EGF-EGFR signaling pathway can be the potential target of therapies for HCC.

Vascular endothelial cells facilitated HCC invasion and metastasis through the Akt and NF-κB pathways induced by paracrine cytokines

Background

It is well documented that cancer cells secrete angiogenic factors to recruit and sustain tumor vascular networks. However, little is known about the effects of endothelial cells on the behavior of tumor cells. The study here was to determine the roles of endothelial cells in HCC cell growth, migration and invasion.

Methods

A mixture of highly metastatic MHCC97H cells and HUVEC cells, as well as MHCC97H cells alone were subcutaneously injected into nude mice to observe the effects of HUVECs on HCC growth. The biological characteristics of MHCC97H cells respectively treated with conditioned medium (CM) derived from HUVECs and endothelial cell basal medium (EBM) in vitro, such as proliferation, migration and invasion, invasion/metastasis associated gene expression, were comparatively analyzed. Differential cytokines between CM and EBM were screened and identified using human cytokine array. Effects of the interested differential cytokine CCL2, IL-8 and CXCL16 and its related signaling pathways were further investigated in HCC cells.

Results

Subcutaneous tumorigenicity of MHCC97H cells in nude mice was promoted by HUVECs and its invasion/metastasis associated genes were significantly upregulated. The in vitro, proliferation, migration and invasion of HCC cells treated with CM were all significantly enhanced as compared to those with EBM stimulation. Simultaneously, PI3K/Akt and ERK1/2 pathway in HCC cells were activated by CM. Total of 25 differential cytokines were identified between CM and EBM such as angiopoietin-2, CCL2 (MCP-1), uPA, endostatin, CXCL16, IL-8, pentraxin 3 etc. The selected differential cytokines CCL2, IL-8 and CXCL16 all modulated the expressions of HCC invasion/metastasis genes, especially MMP2 and MMP9. In exposure to CCL2 or CXCL16 alone, upregulation in AKT phosphorylation but no change in ERK phosphorylation were found in MHCC97H cells, moreover the contents of nuclear transcription factor NF-κB were increased as compared to the control. However, no effects on the activation of Akt and ERK pathway in MHCC97H were found in exposure to IL-8.

Conclusion

This study expands the contribution of endothelial cells to the progression of HCC. It unveils a new paradigm in which endothelial cells function as initiators of molecular crosstalks that enhance survival, migration and invasion of HCC cells.

Rationale and Means to Target Pro-Inflammatory Interleukin-8 (CXCL8) Signaling in Cancer

It is well established that chronic inflammation underpins the development of a number of human cancers, with pro-inflammatory signaling within the tumor microenvironment contributing to tumor progression and metastasis. CXCL8 is an ELR⁺ pro-inflammatory CXC-chemokine which mediates its effects via signaling through two G protein-coupled receptors, CXCR1 and CXCR2. Elevated CXCL8-CXCR1/2 signaling within the tumor microenvironment of numerous cancers is known to enhance tumor progression via activation of signaling pathways promoting proliferation, angiogenesis, migration, invasion and cell survival. This review provides an overview of established roles of CXCL8-CXCR1/2 signaling in cancer and subsequently, discusses the possible strategies of targeting CXCL8-CXCR1/2 signaling in cancer, covering indirect strategies (e.g., anti-inflammatories, NFκB inhibitors) and direct CXCL8 or CXCR1/2 inhibition (e.g., neutralizing antibodies, small molecule receptor antagonists, pepducin inhibitors and siRNA strategies). Reports of pre-clinical cancer studies and clinical trials using CXCL8-CXCR1/2-targeting strategies for the treatment of inflammatory diseases will be discussed. The future translational opportunities for use of such agents in oncology will be discussed, with emphasis on exploitation in stratified populations.

Acidic deoxycholic acid and chenodeoxycholic acid induce interleukin-8 production through p38 mitogen-activated protein kinase and protein kinase A in a squamous epithelial model

BACKGROUND AND AIM

Immune-mediated mucosal inflammation characterized by the production of interleukin (IL)-8 is associated with the development of gastroesophageal reflux disease. The effects of bile acids, which are major components of reflux fluid, on the production of IL-8 and related mechanisms remain unclear. This study aimed to address these questions using an esophageal stratified squamous epithelial model.

METHODS

Normal human esophageal epithelial cells were seeded on the Transwell inserts and cultured with the air-liquid interface system to establish the model. Bile acids under different pH conditions were added to the apical compartment to examine their effects on IL-8 production and the underlying cellular signaling.

RESULTS

Conjugated bile acids under a neutral or acidic condition did not induce IL-8 production, and unconjugated bile acids, deoxycholic acid (DCA), and chenodeoxycholic acid (CDCA) all significantly induced IL-8 production, dose- and time-dependently, only under weakly acid conditions. Inhibition of p38 mitogen-activated protein kinase (p38 MAPK) and protein kinase A (PKA) attenuated the production of IL-8 induced by acidic DCA and CDCA. Inhibition of PKA did not block the bile acid-induced p38 MAPK activation.

CONCLUSIONS

Compared with conjugated bile acids, the unconjugated bile acids DCA and CDCA are more likely to induce IL-8 production in vivo, especially under weakly acid conditions. This process involves two independent signaling pathways, p38 MAPK and PKA.

Role of the microenvironment in the pathogenesis and treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver tumor and the third greatest cause of cancer-related death worldwide, and its incidence is increasing. Despite the significant improvement in management of HCC over the past 30 years, there are no effective chemoprevention strategies, and only one systemic therapy has been approved for patients with advanced tumors. This drug, sorafenib, acts on tumor cells and the stroma. HCC develops from chronically damaged tissue that contains large amounts of inflammation and fibrosis, which also promote tumor progression and resistance to therapy. Increasing our understanding of how stromal components interact with cancer cells and the signaling pathways involved could help identify new therapeutic and chemopreventive targets.

The inflammatory microenvironment in hepatocellular carcinoma: a pivotal role for tumor-associated macrophages

Hepatocellular carcinoma (HCC) is one of the most common and aggressive human cancers worldwide. HCC is an example of inflammation-related cancer and represents a paradigm of the relation occurring between tumor microenvironment and tumor development. Tumor-associated macrophages (TAMs) are a major component of leukocyte infiltrate of tumors and play a pivotal role in tumor progression of inflammation-related cancer, including HCC. Several studies indicate that, in the tumor microenvironment, TAMs acquire an M2-polarized phenotype and promote angiogenesis, metastasis, and suppression of adaptive immunity through the expression of cytokines, chemokines, growth factors, and matrix metalloproteases. Indeed, an established M2 macrophage population has been associated with poor prognosis in HCC. The molecular links that connect cancer cells and TAMs are not completely known, but recent studies have demonstrated that NF-κB, STAT-3, and HIF-1 signaling pathways play key roles in this crosstalk. In this paper, we discuss the current knowledge about the role of TAMs in HCC development, highlighting the role of TAM-derived cytokines, chemokines, and growth factors in the initiation and progression of liver cancer and outlining the signaling pathways involved in the interplay between cancer cells and TAMs.

Inflammatory immune responses in tumor microenvironment and metastasis of hepatocellular carcinoma

Metastasis is a multistage process that requires cancer cells to escape from the primary tumor, survive in the circulation, seed at distant sites and grow. Each of these processes involves rate-limiting steps that are influenced by non-malignant cells of the tumor microenvironment. There are growing evidences that tumors are sustained and promoted by inflammatory signals from the surrounding microenvironment. This review describes experimental data demonstrating the role of the inflammatory immune responses of microenvironment in metastases of hepatocellular carcinoma (HCC), points out the prospective areas for future research and possible new therapeutic approaches to control the metastasis of HCC.

Perioperative dynamic alterations in peripheral regulatory T and B cells in patients with hepatocellular carcinoma

Background

Intratumoral and circulating regulatory T cells (Tregs) have been shown to be critical in the pathogenesis of hepatocellular carcinoma (HCC). However there is limited knowledge on the alterations of regulatory B cells (Bregs). We here investigated perioperative dynamic alterations of peripheral circulating Tregs and Bregs in HCC patients to reveal the relationship between regulatory lymphocytes and its clinical implications.

Methods

36 patients with HCC, 6 with chronic hepatitis B infection and 10 healthy donors were enrolled for this study. Frequencies of peripheral Tregs and Bregs were measured by flow cytometry with antibodies against CD4, CD25, CD127, CD19 and IL-10 before, and after radical surgery. Then, clinical informatics of HCC patients was achieved through Digital Evaluation Score System (DESS) for the assessment of disease severity. Finally, we analysed correlations between digitalized clinical features and kinetics of circulating regulatory lymphocytes.

Results

Level of circulating CD4⁺CD25⁺CD127^- Tregs in HCC patients was significantly lower than that in healthy donors and patients with chronic hepatitis B infection before surgery, but was increased after surgery. Preoperative level of CD19⁺ IL-10⁺ Bregs in HCC patients was also significantly lower than the other groups. However it dramatically was elevated right after surgery and remained elevated compared to controls (about 7 days after surgery, P = 0.04). Frequency of circulating Tregs was correlated with circulating leukocytes, ferritin, and clinical features suggesting tumor aggressiveness including portal vein thrombosis, hepatic vein involvement and advanced clinical stages. Frequency of circulating Bregs was associated with Hepatitis B e Antigen (HBeAg) and Hepatitis B virus (HBV) DNA copy number. In addition, DESS was significantly and positively correlated with other staging systems.

Conclusion

Frequencies of peripheral Tregs and Bregs in HCC patients increased after surgery. These results suggest that a postoperative combination of therapies against Tregs and Bregs may be beneficial for better outcome of HCC patients after resection.