Heat shock protein gp96 drives natural killer cell maturation and anti-tumor immunity by counteracting Trim28 to stabilize Eomes.

The maturation process of natural killer (NK) cells, which is regulated by multiple transcription factors, determines their functionality, but few checkpoints specifically targeting this process have been thoroughly studied. Here we show that NK-specific deficiency of glucose-regulated protein 94 (gp96) leads to decreased maturation of NK cells in mice. These gp96-deficient NK cells exhibit undermined activation, cytotoxicity and IFN-γ production upon stimulation, as well as weakened responses to IL-15 for NK cell maturation, in vitro. In vivo, NK-specific gp96-deficient mice show increased tumor growth. Mechanistically, we identify Eomes as the downstream transcription factor, with gp96 binding to Trim28 to prevent Trim28-mediated ubiquitination and degradation of Eomes. Our study thus suggests the gp96-Trim28-Eomes axis to be an important regulator for NK cell maturation and cancer surveillance in mice.

Induction of Foxp3 and activation of Tregs by HSP gp96 for treatment of autoimmune diseases.

Upregulation and stabilization of Foxp3 expression in Tregs are essential for regulating Treg function and immune homeostasis. In this study, gp96 immunization showed obvious therapeutic effects in a Lyn -/- mouse model of systemic lupus erythematosus. Moreover, gp96 alleviated the initiation and progression of MOG-induced experimental autoimmune encephalomyelitis. Immunization of gp96 increased Treg frequency, expansion, and suppressive function. Gene expression profiling identified the NF-κB family member p65 and c-Rel as the key transcription factors for enhanced Foxp3 expression in Treg by gp96. Mutant gp96 within its Toll-like receptor (TLR) binding domain, TLR2 knockout mice, and mice with cell-specific deletion of MyD88, were used to demonstrate that gp96 activated Tregs and induced Foxp3 expression via a TLR2-MyD88-mediated NF-κB signaling pathway. Taken together, these results show that gp96 immunization restricted antibody-induced and Th-induced autoimmune diseases by integrating Treg expansion and activation, indicating its potential clinical usefulness against autoimmune diseases.

PD-L1 upregulation by IFN-α/γ-mediated Stat1 suppresses anti-HBV T cell response.

Programmed death ligand 1 (PD-L1) has been recently shown to be a major obstacle to antiviral immunity by binding to its receptor programmed death 1 (PD-1) on specific IFN-γ producing T cells in chronic hepatitis B. Currently, IFN-α is widely used to treat hepatitis B virus (HBV) infection, but its antiviral effect vary greatly and the mechanism is not totally clear. We found that IFN-α/γ induced a marked increase of PD-L1 expression in hepatocytes. Signal and activators of transcription (Stat1) was then identified as a major transcription factor involved in IFN-α/γ-mediated PD-L1 elevation both in vitro and in mice. Blockage of the PD-L1/PD-1 interaction by a specific mAb greatly enhanced HBV-specific T cell activity by the gp96 adjuvanted therapeutic vaccine, and promoted HBV clearance in HBV transgenic mice. Our results demonstrate the IFN-α/γ-Stat1-PD-L1 axis plays an important role in mediating T cell hyporesponsiveness and inactivating liver-infiltrating T cells in the hepatic microenvironment. These data raise further potential interest in enhancing the anti-HBV efficacy of IFN-α and therapeutic vaccines.

[Correlation of EBV Infection with Expression of TNF-α-Inducing Protein 3 Gene and A20 Protein in Hodgkin's Lmphoma].

OBJECTIVE: To analyze the correlation of EBV infection with expression of TNF-α-inducing protein 3 gene and A20 protein in Hodgkin lmphoma. METHODS: The clinical data and pathological specimens of 65 cases of Hodgkin's lymphoma in our hospital were analyzed retrospectively, and the tissue chips were made for the rich area of the tumor cells. The latent membrane protein 1 encoded by EBV was measured by immunohistochemical staining, and the RNA encoded by EBV was measured by in situ hybridization to analyze the infection state. The gene expression of tumor necrosis factor.α-induced protein 3 was detected by fluorescence in situ hybridization, and the expression of A20 protein encoded by EBV was detected by immunohistochemical staining. The obtained data were processed by SPSS 23.0 version statistical software. RESULTS: The positive rate of latent membrane protein 1 was 26.15% (17/65), the positive rate of EBV encoded RNA was 26.15% (17/65), and the coincidence rate was 100.00%. In 65 patients, A20 protein expression was lost in 18 cases (27.69%), and 14 cases (21.54%) showed homozygous or heterozygous deletion of tumor necrosis factorα protein 3 gene. Only 1 case showed A20 loss combined with homozygous deletion of TNFα inducible protein 3. Correlation analysis showed that EBV infection did not significantly relate with expression loss of A20 protein and the gene deletion of TNF-α inducing protein 3 (P>0.05). CONCLUSION: The expression loss of A20 protein and gene detection of TNFα inducing protein 3 are found in both EBV negative and positive patients with Hodgkin's lymphoma, however the results of immunohistochemical staining and fluorescence in situ hybridization are not complete consistant, the reason may closely relate with the technical factors.

Posttranscriptional upregulation of HER3 by HER2 mRNA induces trastuzumab resistance in breast cancer.

BACKGROUND: HER2 gene amplification generates an enormous number of HER2 transcripts, but the global effects on endogenous miRNA targets including HER family members in breast cancer are unexplored. METHODS: We generated a HER2-3'UTR expressing vector to test the tumor-promoting properties in HER2 low expressing T47D and MCF7 cells. Through microarray analysis and real-time PCR analysis we identified genes that were regulated by HER2-3'UTR. Positive and negative manipulation of miRNA expression, response element mutational studies and transcript reporter assays were performed to explore the mechanism of competitive sequestration of miR125a/miRNA125b by HER2 3'UTR. To investigate if trastuzumab-induced upregulation of HER3 is also mediated through miRNA de-repression, we used the CRISPR/cas9 to mutate the endogenous HER2 mRNA in HER2 over-expressing Au565 cells. Finally, we looked at cohorts of breast cancer samples of our own and the TCGA to show if HER2 and HER3 mRNAs correlate with each other. RESULTS: The HER2 3'UTR pronouncedly promoted cell proliferation, colony formation, and breast tumor growth. High-throughput sequencing revealed a significant increase in HER3 mRNA and protein levels by the HER2 3'untranslated region (3'UTR). The HER2 3'UTR harboring a shared miR-125a/b response element induced miR-125a/b sequestration and thus resulted in HER3 mRNA derepression. Trastuzumab treatment upregulated HER3 via elevated HER2 mRNA expression, leading to trastuzumab resistance. Depletion of miR-125a/b enhanced the antitumor activity of trastuzumab. Microarray data from HER2-overexpressing primary breast cancer showed significant elevation of mRNAs for predicted miR-125a/b targets compared to non-targets. CONCLUSIONS: These results suggest that HER2 3'UTR-mediated HER3 upregulation is involved in breast cell transformation, increased tumor growth, and resistance to anti-HER2 therapy. The combinatorial targeting of HER3 mRNA or miR-125a/b may offer an effective tool for breast cancer therapy.

[Effect of Lymphocyte/Monocyte Ratio on Clinical Features and Prognosis of Patients with Primary Gastrointestinal Diffuse Large B Cell Lymphoma].

OBJECTIVE: To analyze the effect of lymphocyte/monocyte ratio(LMR) on clinical features and prognosis of patients with primary gastrointestinal diffuse large B cell lymphoma(PGI-DLBCL). METHODS: The clinical data of 38 PGI-DLBCL patients with complete follow-up data in our hospital were analyzed retrospectively. The absolute lymphocyte count(ALC), absolute monocyte count(AMC) and LMR were counted by automating complete blood cell count statistics in newly diagnosed patients, and then the LMR cut off value was obtained by ROC curve. All patients were divided into ≤3.9 group and >3.9 group according to cut off value. RESULTS: Out of 38 patients 21 male and 17 female with a median age 55 old years (29-73 years), 7 cases died, the clinical B symptom occurred in 7 cases (18.4%); the pathologic type of 13 cases (34.2%) belonged to germinal center B-cell like, the primary gastral and intestinal DLBCL were observed in 18 and 20 cases respectively. The chisquare test showed that the LMR associated with of clinical stage and tumor size of PGI-DLBCL. The median survival time was 44 months (7-100 months), and 5-year overrall survival(OS) rate was 78.3% for 38 PGI-DLBCL cases. The univariate analysis showed that age (P=0.021), stage (P=0.012), IPI score (P=0.001), LDH level (P<0.001), tumor size (P=0.037) and LMR (P=0.026) all associate with the 5 years OS rate(%), and the difference was between them statistically significant, but the multivariate analysis showed that only clinical staging is independent risk factors for the OS. CONCLUSION: LMR shows an important effect on clinical features and prognosis of PGI-DLBCL.

FoxO3 inactivation promotes human cholangiocarcinoma tumorigenesis and chemoresistance through Keap1-Nrf2 signaling.

UNLABELLED: FoxO transcription factors have been reported to play pivotal roles in tumorigenesis and drug resistance. The mechanisms underlying the tumor suppression function of FoxOs in human cancers remain largely unknown. Aberrant expression and activation of Nrf2 often correlate with chemoresistance and poor prognosis. Here, we report that FoxO3 directs the basal transcription of Kelch-like ECH-associated protein 1 (Keap1), an adaptor protein that bridges Nrf2 to Cul3 for degradation. FoxO3 depletion resulted in Keap1 down-regulation, thereby activating Nrf2 signaling. We further demonstrated that inhibition of the FoxO3-Keap1 axis accounts for Nrf2 induction and activation induced by constitutively active AKT signaling or tumor necrosis factor α treatment. Unlike previous findings, FoxO3 silencing led to decreased reactive oxygen species production, therefore protecting cells from oxidative stress-induced killing in an Nrf2-dependent manner. Importantly, FoxO3 deficiency strongly potentiated tumor formation in nude mice and rendered cholangiocarcinoma xenografts resistant to cisplatin-induced cell death by activating Nrf2. Additionally, we found that clinical cholangiocarcinoma samples displayed FoxO3-Keap1 down-regulation and Nrf2 hyperactivation, underscoring the essential roles of these proteins in cholangiocarcinoma development. CONCLUSION: Our results unravel a unique mechanism underlying the tumor suppressor function of FoxO3 through constraining Nrf2 signaling. (Hepatology 2016;63:1914-1927).

[Treatment analysis of 26 patients with breast ductal carcinoma in situ].

OBJECTIVE: To study the appropriate surgical treatment for breast ductal carcinoma in situ (DCIS). METHODS: Twenty-six such patients treated between 1992 and 2001 were retrospectively analyzed. Among them, 3 patients were treated by simple mastectomy, 23 patients by mastectomy and axillary lymph node dissection, 8 patients by chemotherapy and one patient by radiotherapy after operation. Median follow-up was 42 m (rang 12 - 112 m). RESULTS: Except 3 of these 26 patients lost in follow-up and 1 patient died from diabetes mellitus, all the other 22 patients survived over 5 years. All lymph nodes dissected from 23 patients were negative. After surgery, 3 patients developed lymph edema of the arm. CONCLUSION: DCIS, lacking the potential of metastasis, is not invasive. Conservative breast surgery without lymph node dissection is feasible for most DCIS patients.