Background Recent studies have suggested that B7-H6, a new member of the B7 family of ligands, not only is a crucial regulator of NK cell-mediated immune responses but also has important clinical ...implications due to its abnormal expression in many human cancers. We have previously reported that higher B7-H6 expression levels in ovarian cancer tissues are positively correlated with tumor metastasis and cancer progression. To date, the expression of B7-H6 in human hepatocellular carcinoma (HCC) and the clinical significance of B7-H6 expression still remain elusive. Methods In the present study, the expression level of B7-H6 was examined in both HCC tissues and HCC cell lines (HepG2 and SMMC-7721). And the clinical significance of B7-H6 was analyzed as well. Results Our results revealed that B7-H6 was expressed abnormally in HCC tissues, which was greatly related to tumor size. The TCGA data also showed that the B7-H6 mRNA expression level was significantly negatively correlated with the survival of HCC patients. Next, to investigate the functions of B7-H6 in HCC, we successfully constructed B7-H6 knockdown expression human HCC cell lines using the RNA interference technology. Our studies showed that reduced expression of B7-H6 in HepG2 and SMMC-7721 cells significantly attenuated cell proliferation as well as cell migration and invasion. Besides, depletion of B7-H6 greatly induced cell cycle arrest at G1 phase. And also B7-H6 knockdown in HCC cell lines dramatically decreased the C-myc, C-fos and Cyclin-D1 expression. Conclusions Our present findings suggested that B7-H6 played an important role in oncogenesis of HCC on cellular level, and B7-H6 could be employed to develop immunotherapeutic approaches targeting this malignancy.
BackgroundRegulatory T cells (Treg) are an integral part of the tumor immune tolerance. Carcinoma-associated fibroblasts (CAFs) is a pivotal driver for accumulation of Treg cells in the tumor ...microenvironment (TME). The molecular nature underpinning Treg cells and CAFs coupling needs to be further defined.MethodsThe Il1r2flox/floxFoxp3Cre mice were generated to establish the conditional knock-out of Il1r2 in Foxp3+ Tregs in vivo. Using the MC38 tumor model, we evaluated the antitumor efficacy of immune checkpoint inhibitors (ICIs) and further analyzed the immune profiling of the TME by multicolor flow cytometry. Single-cell RNA sequencing of the whole tumor tissues, TCR repertoire analysis of sorted CD3+ TILs were also performed.ResultsWe showed that IL1 receptor 2 (IL1R2), a decoy receptor that neutralizes IL1, was highly expressed in Treg cells in the TME. In addition, we found that Il1r1 was largely expressed in the CAFs, suggesting IL1R2 plays a role in modulating crosstalk between Tregs and CAFs. We further demonstrated that Il1r2 deficiency in Treg cells led to greater antitumor efficacy of ICI, decreased Tregs and increased CD8+ T cells in the TME, as well as reduced levels of T cell dysfunction. Mechanistically, we showed that IL1 inhibited major histocompatibility complex class II (MHC-II) expression on fibroblasts and Treg-specific Il1r2 deletion led to a decrease in genes associated with MHC-II antigen presentation in CAFs.ConclusionsOur study established a critical role of IL1 signaling in inhibiting Treg-mediated tumor immune suppression through downregulating MHC-II antigen presentation in CAFs.
This study was to investigate the mechanism and role of Kif4A in doxorubicin-induced apoptosis in breast cancer. Using two human breast cancer cell lines MCF-7 (with wild-type p53) and MDA-MB-231 ...(with mutant p53), we quantitated the expression levels of kinesin super-family protein 4A (Kif4A) and poly (ADP-ribose) Polymerase-1 (PARP-1) by Western blot after doxorubicin treatment and examined the apoptosis by flow cytometry after treatment with doxorubicin and PARP-1 inhibitor, 3-Aminobenzamide (3-ABA). Our results showed that doxorubicin treatment could induce the apoptosis of MCF-7 and MDA-MB-231 cells, the down-regulation of Kif4A and upregulation of poly(ADP-ribose) (PAR). The activity of PARP-1 or PARP-1 activation was significantly elevated by doxorubicin treatment in dose- and time-dependent manners (P < 0.05), while doxorubicin treatment only slightly elevated the level of cleaved fragments of PARP-1 (P > 0.05). We further demonstrated that overexpression of Kif4A could reduce the level of PAR and significantly increase apoptosis. The effect of doxorubicin on apoptosis was more profound in MCF-7 cells compared with MDA-MB-231 cells (P < 0.05). Taken together, our results suggest that the novel role of Kif4A in doxorubicin-induced apoptosis in breast cancer cells is achieved by inhibiting the activity of PARP-1.
We have previously reported that the higher expression of TF in human esophageal cancer tissues was significantly associated with tumor invasion, intratumoral microvessel density and patients' ...postoperative prognoses. Besides its trans-membranous form, TF also has alternatively spliced transcripts. In the present study, the transcripts of the two TF isoforms, flTF and asTF, in human gastric cancer tissues were determined by real-time PCR, and the correlation between the expression of TF isoforms and patient's clinicopathological features was also analyzed. Our results showed that the relative mRNA expression levels of flTF and asTF in human gastric cancer tissues was significantly higher than those in normal tissues (
=0.035 and
=0.006, respectively). The relative mRNA expression level of asTF was significantly associated with age (
=0.018), meanwhile, we could not find that flTF or asTF expression level was correlated with any other characteristics of the patients, including gender, TNM stage, pathological grade, tumor size, histological type, or chemotherapy sensitivity. Univariate analysis demonstrated that the overall survival rate of gastric cancer patients with lower flTF or asTF expression level was greater than those with higher expression level (
=0.018 and =0.038, respectively). Multivariate COX model analysis also demonstrated that flTF expression (
=0.048) or asTF expression (
=0.002) could be used as independent prognostic predictors in human gastric cancer. Thus, both flTF and asTF mRNA expression levels in cancer tissues could be used as useful risk factors for evaluating the prognoses of patients suffering from gastric cancer.
Evidence suggests that fatty acid receptor FFAR4 plays a tumor-promoting role in adipose tissue-adjacent malignancies, but its clinical relevance remains unexplored. Here, we investigated the ...clinical significance and underlying mechanisms of FFAR4 in hormone receptor-positive breast cancer (HRPBC).
FFAR4 expression was assessed by immunohistochemistry in an exploration cohort of 307 breast cancer cases collected from two independent institutes. Two public breast cancer microarray datasets served as validation cohorts. Gas chromatography-mass spectrometry was employed to identify FFAR4 ligands in normal and cancerous breast tissues. Survival analyses were performed in all cohorts and designated molecular subgroups. Mechanistic studies were performed in vitro in hormone receptor-positive breast cancer cell lines MCF-7 and T-47D.
Aberrant FFAR4 expression and endogenous FFAR4 ligands were identified in breast cancer tissues, five FFAR4 ligands showed significantly elevated proportions in cancerous versus normal tissues. In the exploration cohort, FFAR4 was demonstrated as an independent prognostic factor for recurrences (HR: 2.183, 95% CI: 1.360-3.504, P = 0.001) and breast cancer-specific deaths (HR: 2.102, 95% CI: 1.173-3.766, P = 0.013) in HRPBC cases. In contrast, FFAR4 expression was not associated with prognosis in hormone receptor-negative cases. In the validation cohorts, FFAR4 mRNA levels were also observed to be associated with disease recurrence in estrogen receptor-positive cases, but not so in estrogen receptor-negative cases. FFAR4 activation by endogenous ligands and a synthetic ligand TUG891 significantly dampened tamoxifen's efficacy on HRPBC cells, whereas FFAR4 knockdown or antagonist AH7614 abrogated this effect. Furthermore, FFAR4-induced tamoxifen resistance was dependent on ERK and AKT pathways in HRPBC.
Our results establish a novel role of FFAR4 and its ligands in the complicated interactions between tissue lipid profile and cancer biology. FFAR4 signaling confers tamoxifen resistance in HRPBC cell line and FFAR4 expression can serve as a prognostic biomarker for tamoxifen-treated HRPBC patients. FFAR4 may serve as a potential target for anti-breast cancer therapies, especially in endocrine resistant cases.
T-bet, a member of the T-box family of transcription factors, is a key marker of type I immune response within the tumor microenvironment, and has been previously reported by us to serve as an ...important prognostic indicator for human gastric cancer patients and a potential biomarker for immunotherapy. In the present study, we aimed to assess the clinical significance and prognostic value of T-bet+ tumor-infiltrating lymphocytes in human epithelial ovarian cancer.
The immunohistochemistry was used to analyze the infiltration density of T-bet+ lymphoid cells in human epithelial ovarian cancer tissues, and the flow cytometry analysis was used to further analyze the presence of T-bet+ tumor-infiltrating lymphocytes subgroups in cancer tissues.
Our immunohistochemistry analysis showed increased number of T-bet+ lymphoid cells in the human epithelial ovarian cancer tissues, and the flow cytometry analysis further demonstrated the presence of T-bet+ tumor-infiltrating lymphocytes subgroups including CD4+ , CD8+ T cells and NK cells. In addition, we also observed a significant association of T-bet+ tumor-infiltrating lymphocytes density in the tumor nest of cancer with not only serum CA125 levels but also with distant metastasis. However no association was observed with other characteristics like patients' age, pathological type, FIGO stage, tumor site and tumor size. Furthermore, the survival analysis showed that higher density of T-bet+ tumor-infiltrating lymphocytes both in tumor nest and tumor stroma of cancer tissues was significantly associated with better patient survival. In addition, the density of T-bet+ tumor-infiltrating lymphocytes in tumor nest appeared to be an independent risk factor for predicting patients' postoperative prognoses.
Our data indicated that the key transcription factor T-bet might play an important role in the type I immune cells mediated antitumor response, and the density of T-bet+ lymphocytes in human epithelial ovarian cancer tissues could serve as a prognostic predictor for ovarian cancer patients.
The present study examined programmed death-1 ligand-1 (PD-L1) detected by immunohistochemical labeling in 102 cases of human gastric carcinoma, 10 adenoma and 10 normal tissues. The relationship ...between PD-L1 immunolocalization and clinical pathological features, as well as the prognosis of gastric carcinoma, was explored. There was no PD-L1 detectable in normal gastric tissues and very weak immunolabeling in gastric adenomas, but it could be detected in 42.2% of gastric carcinoma tissues. There was no correlation between PD-L1 immunolocalization and patient age, sex, tumor location or the degree of tumor differentiation in the gastric carcinomas. However, PD-L1 immunodetection was significantly correlated to tumor size, invasion, lymph node metastasis and survival time of patients. PD-L1 immunolabeling was significantly enhanced (
P
<
0.01
) when the tumor infiltrated into the deep muscular layers, with lymph node metastasis or survival time of less than 2 years, Moreover, multivariate analysis demonstrated that PD-L1 immunodetection could be used as an independent factor to evaluate the prognosis of gastric carcinoma.
In the present study, we aimed to investigate the role of epidermal growth factor receptor (EGFR) pathway in the up-regulation of programmed death ligand-1 (PD-L1) caused by radiotherapy (RT).
Tissue ...microarrays (TMA) consisting of glioma cancer specimens from 64 patients were used to examine the correlation between PD-L1 and EGFR levels. Furthermore, we performed in vitro experiments to assess the role of EGFR pathway in RT-upregulated PD-L1 expression using human glioma cell lines U87 and U251.
Our data demonstrated that the PD-L1 expression was significantly correlated with EGFR expression in glioma specimens (χ2=5.00, P=0.025). The expressions of PD-L1 at the protein and mRNA levels were both significantly up-regulated by RT (P<0.05). The expressions of phosphorylated EGFR and janus kinase 2 (JAK2) were also induced by RT (P<0.05). Besides, inhibition of EGFR pathway could abrogate the RT-triggered PD-L1 up-regulation (P>0.05). The combination of RT with EGFR inhibitor exhibited the same effect on antitumor immune response compared with the combination of RT with PD-L1 neutralizing antibody (Ab).
RT could up-regulate the PD-L1 expression through the pathways downstream of EGFR in glioma.
•The PD-L1 expression was significantly correlated with EGFR expression in glioma specimens.•RT promoted the phosphorylation of EGFR to activate the JAK2 pathway, which resulted in the upregulation of PD-L1.•Inhibition of EGFR pathway could abrogate the RT-triggered PD-L1 up-regulation.
Glioma is a highly lethal and common central nervous system tumor with poor 5-year survival rate. It is still urgently necessary to develop more effective therapeutic strategies for glioma. We found radiotherapy up-regulated the PD-L1 expression through the pathways downstream of EGFR in glioma. This finding provides new evidence for the combination of RT with PD-1/PD-L1 or EGFR-TKI inhibitor. That may contribute to the development of new therapeutic strategy for glioma.
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