ACOX2 deficiency: A disorder of bile acid synthesis with transaminase elevation, liver fibrosis, ataxia, and cognitive impairment

Acyl CoA Oxidase 2 (ACOX2) encodes branched-chain acyl-CoA oxidase, a peroxisomal enzyme believed to be involved in the metabolism of branched-chain fatty acids and bile acid intermediates. Deficiency of this enzyme has not been described previously. We report an 8-y-old male with intermittently elevated transaminase levels, liver fibrosis, mild ataxia, and cognitive impairment. Exome sequencing revealed a previously unidentified homozygous premature termination mutation (p.Y69*) in ACOX2 Immunohistochemistry confirmed the absence of ACOX2 expression in the patient's liver, and biochemical analysis showed marked elevation of intermediate bile acids upstream of ACOX2. These findings define a potentially treatable inborn error of bile acid biosynthesis caused by ACOX2 deficiency

Small cell lung cancer stem cells display mesenchymal properties and exploit immune checkpoint pathways in activated cytotoxic T lymphocytes

Small cell lung cancer (SCLC) is an aggressive tumor type with early dissemination and distant metastasis capacity. Even though optimal chemotherapy responses are observed initially in many patients, therapy resistance is almost inevitable. Accordingly, SCLC has been regarded as an archetype for cancer stem cell (CSC) dynamics. To determine the immune-modulatory influence of CSC in SCLC, this study focused on the characterization of CD44(+)CD90(+) CSC-like subpopulations in SCLC. These cells displayed mesenchymal properties, differentiated into different lineages and further contributed to CD8(+) cytotoxic T lymphocytes (CTL) responses. The interaction between CD44(+)CD90(+) CSC-like cells and T cells led to the upregulation of checkpoint molecules PD-1, CTLA-4, TIM-3, and LAG3. In the patient-derived lymph nodes, CD44(+) SCLC metastases were also observed with T cells expressing PD-1, TIM-3, or LAG3. Proliferation and IFN-γ expression capacity of TIM-3 and LAG3 co-expressing CTLs are adversely affected over long-time co-culture with CD44(+)CD90(+) CSC-like cells. Moreover, especially through IFN-γ secreted by the T cells, the CSC-like SCLC cells highly expressed PD-L1 and PD-L2. Upon a second encounter with immune-experienced, IFN-γ-stimulated CSC-like SCLC cells, both cytotoxic and proliferation capacities of T cells were hampered. In conclusion, our data provide evidence for the superior potential of the SCLC cells with stem-like and mesenchymal properties to gain immune regulatory capacities and cope with cytotoxic T cell responses. With their high metastatic and immune-modulatory assets, the CSC subpopulation in SCLC may serve as a preferential target for checkpoint blockade immunotherapy

A novel Bifidobacterium infantis-mediated TK/GCV suicide gene therapy system exhibits antitumor activity in a rat model of bladder cancer

Bladder cancer is the ninth most common malignancy in the world. Successful clinical management remains a challenge. In order To search for novel targeted and efficacious treatment, we sought to investigate anti-tumor activity of BI-TK suicide gene therapy system in a rat model of bladder tumors. We first constructed and tested an anaerobic Bifidobacterium infantis-mediated thymidine kinase (BI-TK) suicide gene therapy system. To test the in vivo efficacy of this system, we established a rat model of bladder tumors, which was induced by N-methyl-nitrosourea perfusion. Bifidobacterium infantis containing the HSV-TK (i.e., BI-TK) were constructed by transformation of recombinant plasmid pGEX - TK. The engineered BI-TK was injected into tumor-bearing rats via tail vein, followed by intraperitoneal injection of ganciclovir (GCV). Using the rat model of bladder tumors, we found that bladder tumor burdens were significantly lower in the rats treated with BI-TK/GCV group than that treated with normal saline control group (p <0.05). While various degrees of apoptosis of the tumor cells were detected in all groups using in situ TUNEL assay, apoptosis was mostly notable in the BI-TK/GCV treatment group. Immunohistochemical staining further demonstrated that the BI-TK/GCV treatment group had the highest level of caspase3 protein expression than that of the empty plasmid group and normal saline group (p < 0.05). Thus, our results demonstrate that the Bifidobacterium infantis-mediated TK/GCV suicide gene therapy system can effectively inhibit rat bladder tumor growth, possibly through increasing caspase 3 expression and inducing apoptosis

Human Tumour Immune Evasion via TGF-β Blocks NK Cell Activation but Not Survival Allowing Therapeutic Restoration of Anti-Tumour Activity

Immune evasion is now recognized as a key feature of cancer progression. In animal models, the activity of cytotoxic lymphocytes is suppressed in the tumour microenvironment by the immunosuppressive cytokine, Transforming Growth Factor (TGF)-β. Release from TGF-β-mediated inhibition restores anti-tumour immunity, suggesting a therapeutic strategy for human cancer. We demonstrate that human natural killer (NK) cells are inhibited in a TGF-β dependent manner following chronic contact-dependent interactions with tumour cells in vitro. In vivo, NK cell inhibition was localised to the human tumour microenvironment and primary ovarian tumours conferred TGF-β dependent inhibition upon autologous NK cells ex vivo. TGF-β antagonized the interleukin (IL)-15 induced proliferation and gene expression associated with NK cell activation, inhibiting the expression of both NK cell activation receptor molecules and components of the cytotoxic apparatus. Interleukin-15 also promotes NK cell survival and IL-15 excluded the pro-apoptotic transcription factor FOXO3 from the nucleus. However, this IL-15 mediated pathway was unaffected by TGF-β treatment, allowing NK cell survival. This suggested that NK cells in the tumour microenvironment might have their activity restored by TGF-β blockade and both anti-TGF-β antibodies and a small molecule inhibitor of TGF-β signalling restored the effector function of NK cells inhibited by autologous tumour cells. Thus, TGF-β blunts NK cell activation within the human tumour microenvironment but this evasion mechanism can be therapeutically targeted, boosting anti-tumour immunity

Granulocytic subset of myeloid derived suppressor cells in rats with mammary carcinoma

Item does not contain fulltextLimited knowledge is available on myeloid derived suppressor cells (MDSCs) of rat origin. We examined the myeloid cells from peripheral blood, bone marrow and spleens of healthy and mammary tumor bearing rats employing a novel immunophenotyping strategy with CD172a, HIS48, and Rp-1 antibodies. We addressed rat granulocytes by Rp-1 positivity and used HIS48 in discrimination of two mononuclear cell subsets. An expansion of granulocyte numbers was detected in peripheral blood and spleens of mammary tumor-bearing animals. The purified granulocytes were able to impair antigen-specific helper T-cell proliferation, and therefore nominated as granulocytic MDSCs of this rat tumor model. HIS48+ mononuclear cell numbers were also increased in the blood and spleens of mammary tumor bearing rats with a lower MHC class II positivity. Despite the lack of an antigen specific suppression of CD4+ T cells, HIS48+ monocytes resemble monocytic MDSCs with their inflammatory phenotype. Together, these results provide evidence for the existence and phenotypic characterization of a granulocytic MDSC subset in a rat model of mammary carcinoma

Coexistence of different tissue tumourigenesis in an N-methyl-N-nitrosourea-induced mammary carcinoma model: a histopathological report in Sprague-Dawley rats

Esendagli, Gunes/0000-0003-4865-2377;WOS: 000262991000009PubMed: 18987061N-methyl-N-nitrosourea (MNU), a highly potent carginogen, is widely used to generate mammary tumours in murine species. In a model of MNU-induced mammary carcinogenesis using immature female Sprague-Dawley rats, large mammary tumours (largest dimension >= 0.5 cm) were obtained within a very short period of time. In addition, in the rats bearing MNU-induced mammary carcinomas, there were a number of tumours whose origins were not from mammary tissue but from several different tissues and from mammary non-epithelial tissue. The tumours were of mesenchymal or epithelial origin and they were located in the inguinal region. These tumours were diagnosed as fibroadenoma, combined tubular adenoma and fibroadenoma, hyperkeratotic papilloma, keratinous cyst and malignant peripheral nerve sheath tumour (MPNST) with smooth muscle differentiation. The occurrence of these other tumours in addition to the development of the mammary carcinomas may be attributed to a direct local effect of the intraperitoneal administration of MNU during the sexual development of the immature rats. In the MNU-induced mammary tumour model, coexistence of tumourigenesis in various non-mammary tissues should be considered an important factor that may interfere with experimental procedures and results and also the quality of life of the tumour-bearing animals.Eczacibasi Scientific Research and Award Fund; Hacettepe University Scientific Research UnitHacettepe University [05DO3104001]This study was supported by grants from the Eczacibasi Scientific Research and Award Fund and the Hacettepe University Scientific Research Unit (project no. 05DO3104001). We Wish to thank Dr Sibel Percinel for her helpful supervision in the histopathological evaluations

pTARGET vector carrying IL-18 or CD40L genes for attenuated Salmonella typhimurium mediated gene therapy.

45th Annual Meeting of the American-Society-of-Hematology -- DEC 06-09, 2003 -- SAN DIEGO, CALIFORNIAEsendagli, Gunes/0000-0003-4865-2377;WOS: 000186537101986…Amer Soc Hemato

Salmonella typhimurium aroB-encoding murine IL-18 or CD40L: evaluation for gene therapy

31st Congress of the Federation-of-European-Biochemical-Societies (FEBS) -- JUN 24-29, 2006 -- Istanbul, TURKEYEsendagli, Gunes/0000-0003-4865-2377;WOS: 000238914000163…Federat European Biochem So

Liver resection modulates hepatic chemokine levels in breast cancer

BACKGROUND: Resection of metastatic hepatic tumors of breast cancer may result in the acceleration of hepatic and extrahepatic tumor progression due to the microenvironmental circulation of chemokines. This study aimed to investigate the effect of hepatectomy on a large panel of chemokines, liver regeneration, and myeloid cell levels in an experimental breast cancer model. METHODS: The 4T1 breast cancer cells were inoculated, and 30% to 40% hepatectomy was performed. Mice without tumors or only laparotomy (no hepatectomy) served as control groups. After 14 days (short-term) and 21 days (long-term), tissue samples were obtained from the regions near and distant from the resection site. Chemokine levels were evaluated by enzyme-linked immunosorbent assay arrays. Myeloid infiltration in the liver and the primary tumor and hepatic regeneration status were also histopathologically evaluated. RESULTS: The levels of pro-tumorigenic chemokines such as CCL2, CCL3, CCL4, and CCL5 were elevated in hepatectomized tumor-bearing animals. This observation was consistent with the presence of hepatic metastases. Liver regeneration and myeloid cell infiltration showed significant differences between the tumor-bearing hepatectomized groups followed in the short and long term. CONCLUSION: Our study showed elevation and variations in chemokines after hepatectomy, with a prominent increase in pro-tumorigenic chemokines. These results can be associated with the acceleration of metastasis after liver resection. However, further prospective studies are required to better define the impact of resection, which may transform the liver into a favorable site for metastasis