Epstein Barr Virus-positive large T-cell lymphoma presenting as acute appendicitis 17 years after cadaveric renal transplant: a case report

<p>Abstract</p> <p>Introduction</p> <p>The majority of post-transplant lymphoproliferative disorders in renal transplant patients are of the B-cell phenotype, while the T-cell phenotype is rare. We report a case of Epstein Barr Virus-positive, T-cell lymphoma in a renal transplant patient, presenting unusually as acute appendicitis.</p> <p>Case presentation</p> <p>A 45-year-old Hispanic male renal transplant patient presented with right-side abdominal pain 17 years after transplant. The laboratory studies were unremarkable. Laparoscopic exploration showed an inflamed appendix so a laparoscopic appendectomy was performed. Pathology of the appendix showed large cells positive for CD3, CD56 and Epstein Barr Virus-encoded RNA staining, and negative for CD20 and CD30. The tissue tested positive for T-cell receptor gene rearrangement by polymerase chain reaction analysis. Treatment management involved reduction of immunosuppression and initiation of chemotherapy with cisplatin, etoposide, gemcitabine, and solumedrol followed by cyclophosphamide, hydroxydaunorubicin, vincristine and prednisone). He recovered and the allo-grafted kidney is fully functional.</p> <p>Conclusion</p> <p>We report a rare case of post-renal transplant large T-cell lymphoma, with an unusual presentation of acute appendicitis and Epstein Barr Virus-positivity, which responded well to chemotherapy.</p

Inducible Caspase9-mediated suicide gene for MSC-based cancer gene therapy

Cellular therapies based on mesenchymal stromal/stem cells (MSC) are promising strategies in regenerative medicine and oncology. Despite encouraging results, there is still some level of concerns on inoculating MSC in cancer patients. To face this issue, one possibility resides in engineering MSC by incorporating a suicide gene in order to control their fate once infused. Strategies based on Herpes Simplex Virus Thymidine Kinase (HSV-TK) and the Cytosine Deaminase genes have been developed and more recently a novel suicide gene, namely, iCasp9, has been proposed. This approach is based on a variant of human Caspase9 that binds with high affinity to a synthetic, bioinert small molecule (AP20187) leading to cell death. Based on this technology so far marginally applied to MSC, we tested the suitability of iCasp9 suicide strategy in MSC to further increase their safety. MSC have been transfected by a lentiviral vector carrying iCasp9 gene and then tested for viability after AP20187 treatment in comparison with mock-transfected cells. Moreover, accounting our anti-tumor approaches based on MSC expressing potent anti-cancer ligand TNF-Related Apoptosis-Inducing Ligand (TRAIL), we generated adipose MSC co-expressing iCasp9 and TRAIL successfully targeting an aggressive sarcoma type. These data show that anti-cancer and suicide mechanisms can coexist without affecting cells performance and hampering the tumoricidal activity mediated by TRAIL. In conclusion, this study originally indicates the suitability of combining a MSC-based anti-cancer gene approach with iCasp9 demonstrating efficiency and specificity

The significance of peroxisomes in secondary metabolite biosynthesis in filamentous fungi

Peroxisomes are ubiquitous organelles characterized by a protein-rich matrix surrounded by a single membrane. In filamentous fungi, peroxisomes are crucial for the primary metabolism of several unusual carbon sources used for growth (e.g. fatty acids), but increasing evidence is presented that emphasize the crucial role of these organelles in the formation of a variety of secondary metabolites. In filamentous fungi, peroxisomes also play a role in development and differentiation whereas specialized peroxisomes, the Woronin bodies, play a structural role in plugging septal pores. The biogenesis of peroxisomes in filamentous fungi involves the function of conserved PEX genes, as well as genes that are unique for these organisms. Peroxisomes are also subject to autophagic degradation, a process that involves ATG genes. The interplay between organelle biogenesis and degradation may serve a quality control function, thereby allowing a continuous rejuvenation of the organelle population in the cells

Human cytomegalovirus latency-associated proteins elicit immune-suppressive IL-10 producing CD4⁺ T cells.

Human cytomegalovirus (HCMV) is a widely prevalent human herpesvirus, which, after primary infection, persists in the host for life. In healthy individuals, the virus is well controlled by the HCMV-specific T cell response. A key feature of this persistence, in the face of a normally robust host immune response, is the establishment of viral latency. In contrast to lytic infection, which is characterised by extensive viral gene expression and virus production, long-term latency in cells of the myeloid lineage is characterised by highly restricted expression of viral genes, including UL138 and LUNA. Here we report that both UL138 and LUNA-specific T cells were detectable directly ex vivo in healthy HCMV seropositive subjects and that this response is principally CD4⁺ T cell mediated. These UL138-specific CD4⁺ T cells are able to mediate MHC class II restricted cytotoxicity and, importantly, show IFNγ effector function in the context of both lytic and latent infection. Furthermore, in contrast to CDCD4⁺ T cells specific to antigens expressed solely during lytic infection, both the UL138 and LUNA-specific CD4⁺ T cell responses included CD4⁺ T cells that secreted the immunosuppressive cytokine cIL-10. We also show that cIL-10 expressing CD4⁺ T-cells are directed against latently expressed US28 and UL111A. Taken together, our data show that latency-associated gene products of HCMV generate CD4⁺ T cell responses in vivo, which are able to elicit effector function in response to both lytic and latently infected cells. Importantly and in contrast to CD4⁺ T cell populations, which recognise antigens solely expressed during lytic infection, include a subset of cells that secrete the immunosuppressive cytokine cIL-10. This suggests that HCMV skews the T cell responses to latency-associated antigens to one that is overall suppressive in order to sustain latent carriage in vivo

Role of nuclear Met receptor in hepatocellular carcinoma

Poster Session - Oncogenes, Growth Factors, and Signal Transducers 2: abstract no. 5266Met is a receptor tyrosine kinase encoded by c-Met proto-oncogene which triggers a wide range of normal physiological signaling cascades upon activation by hepatocyte growth factor (HGF). However, aberrant Met expression and activity are commonly found in human cancers. Emerging evidence has shown the presence of nuclear Met (nMet) in some cancerous tissues and cell lines, suggesting that nMet could have unexplored functions in the nucleus. Met is an attractive therapeutic target for human cancers. Indeed, therapeutic antibodies and inhibitors that antagonize dysregulated Met are currently in clinical trials. However, the classic therapeutic strategies against the Met surface receptor will unequivocally exhibit limitations in acting against nMet. Despite the oncogenic role of Met in hepatocellular carcinoma (HCC), the existence and functions of nMet in HCC has never been reported. In this study, we aim to evaluate the clinical relevance and characterize the functions of nMet in HCC. We studied nMet expression in 103 human HCC paired samples by immunohistochemistry. Our data showed that nMet was overexpressed in 89.3% of HCC tissues and its expression was progressively increased along HCC development. Nonetheless, nMet overexpression was significantly associated with venous invasion and poorer overall survival. We found that nMet, which has a lower molecular weight than Met, could only be detected using an antibody against the carboxyl terminus of Met (C28) in tumorous tissues. This finding suggests that nMet only comprises the carboxyl cytoplasmic region of full length Met. Immunofluorescence microscopy showed that juxtamembrane deletion of Met accumulates in the nucleus whereas truncated tyrosine kinase domain accumulates in the cytoplasm, implying a region important for nuclear localization of the cytoplasmic fragment. Cellular fractionation also confirmed the existence of nMet in the nuclear fraction of HCC cells. To explore the functional role of nMet, expression vector was constructed to express the cytoplasmic protein of Met in cells. In vitro functional study showed that overexpression of nMet augments the invasiveness of HCC cells suggesting the unexplored functional effect of nMet exerted within nucleus in promoting HCC invasiveness. Furthermore, we showed that nMet activates NF-kappaB reporter activity which might enhance the pro-metastatic gene expression to promote tumor invasiveness and aggressiveness.link_to_OA_fulltex

Clinical relevance and functional role of nuclear Met in hepatocellular carcinoma

Session title: Gastrointestinal Malignancies - Noncolorectal CancerECC 2013 includes: 17th ECCO - 38th ESMO - 32nd ESTRO European Cancer CongressPoster presentation, poster no. 2469Conference Theme: Reinforcing Multidisciplinarit

Role of nuclear Met-derived exosomes in hepatocellular carcinoma metastasis and lung premetastatic niche formation

Conference Theme: From basic research to precision medicineThis journal suppl. entitled: 24th Biennial Congress of the European Association for Cancer Research, 9–12 July 2016, Manchester, UKPoster Session: Cell and Tumour Biology 1: no. 321INTRODUCTION: Emerging evidences has shown that nuclear Met (nMet) is expressed in some cancerous tissues and cell lines, suggesting Met could have unexplored functions inside nucleus. Our previous study have provided the first evidence about the clinical relevance of nMet in hepatocellular carcinoma (HCC). The present study was aimed to assess the role of exosomes isolated from nMet overexpressing cell line in promoting HCC metastasis as well as formation of lung premetastatic niche. MATERIAL AND METHOD: Exosomes were isolated from metastatic MHCC97L HCC cell in which nMet was overexpressed using ExoQuick solution. The integrity and size of isolated exosomes were examined by both electron microscopy and NanoSight. Immunoblotting was performed to determine the exosomal marker of isolated exosomes. Normal liver and na¨ıve HCC cells were treated with isolated exosomes and functional assays including Transwell migration and invasion assays were performed. The uptake of nMet-exosomes were investigated by fluorescence microscopy. Nude mice were injected with nMet-exosomes to study the HCC metastasis and lung premetastatic niche formation. RESULTS AND DISCUSSION: In our present study, exosomes were isolated from conditioned media of control MHCC97L/Vec and MHCC97L/nMet cells. Transmission electron microscopy images of isolated exosomes revealed typical exosome structure with diameter of approximately 50−80 nm. Immunoblotting showed that the isolated exosomes were positive for exosomal markers (Alix, TSG101 and CD9) while depleted of the cytoskeletal protein alpha-tubulin, cis-Golgi marker GM130 and nucleoporin p62. Further functional assays showed that nMet-exosomes significantly augmented both migratory and invasive properties of normal liver (MIHA) and na¨ıve HCC cells (BEL7402 and MHCC97L). We also labeled exosomes with PKH26 and observed the uptake of exosomes by na¨ıve cells with fluorescence microscopy. Intravenous injection of nMet-exosomes was administered prior to orthotopic liver implantation of tumor xenograft in nude mice. nMet-exosomes treated mice displayed enhanced incidence of distant metastasis from HCC primary tumor to lungs when compared with control mice, suggesting the promoting effect of nMet-exosomes on distant metastasis and lung premetastatic niche formation. CONCLUSION: Our findings will provide useful evidences about tumor-derived exosomes in driving metastasis and yield novel mechanistic insights into liver cancer metastasis

Nuclear met is overexpressed and promotes tumorigenesis and metastasis in hepatocellular carcinoma

Congress Theme: Translating Discoveries into Prevention and Cure

Rab20 and Rab30 regulate hepatocellular carcinoma (HCC) for tumor suppression

Poster Session: Carcinogenesis 2: no. 204This journal suppl. entitled: 24th Biennial Congress of the European Association for Cancer Research, 9–12 July 2016, Manchester, UKConference Theme: From basic research to precision medicineRas related in brain 20 (Rab20) and Ras related in brain 30 (Rab30) are members of the Rab family of small GTP-binding proteins. Rab proteins contribute to the control of vesicular traffic in eukaryotic cells, by which they mainly regulate the precision of vesicle transportation along the biosynthesis/secretary pathway. Rab20 and Rab30 are low-weight GTPase that localise in the Golgi apparatus. Rab20 participates in apical endocytosis and phagosome functions, while Rab30 is important for controlling the structural integrity of the Golgi apparatus. Functions of Rab20/30 in cancer development have not been fully understood. Rab20 was identified to be upregulated in pancreatic cancer, and should be associated wih early stage of pancreatic carcinogenesis. However, roles of Rab30 has not been published in any cancer research. This drives us to investigate the potential roles of Rab20/30 in the development of hepatocellular carcinoma (HCC). In order to evaluvate the expression of Rab20 and Rab30 in HCC, 30 clinical cases were randomly selected for Real-time quantitative PCR using Rab20/30 TaqMan Gene Expression Assays (Applied Biosystem®). HPRT was selected as the internal control for normalization. Clinicopathological correlation and statistical analysis were performed to determine their expression ratios of tumorous to non-tumorous samples and potential roles in HCC development. Expessions of Rab20/30 were also determined in nine HCC cell lines through qPCR. Selected cell lines included MIHA, BEL7402, Hep3B, HLE, Huh7, PLC/PRF/5, SMMC7721, MHCC97L and MHCC-LM3. Our qPCR results reflected both Rab20 and Rab30 were significantly down-regulated in tumorous samples when compared to non-tumourous samples, with the p-value of 0.0115 and 0.0004, respectively. Regarding to tumor stage, underexpresssion of Rab20 was mainly observed in patients with stage III-IV, which is regarded as late stage. In contrast, apart from patients with stage III-IV, underexpression of Rab30 was also detected in patients with stage I-II. This suggested Rab20 maybe responsible for HCC progression by inhibiting invasive and metastatic properties of HCC, while Rab30 may play roles in the initiation of hepatocarcinogenesis. None of the clinicopathological parameters tested was significantly associated to the expression of Rab20/30. For HCC cell line panel, Rab20 was highly expressed in MIHA and BEL7402, but slightly expressed in other cell lines. There was no obvious expression pattern of Rab30 in HCC cell lines. Through qPCR, Rab20 and Rab30 were underexpressed in HCC, implying their potenital role in tumor suppression. Rab20 was mainly down-regulated in late stages, while underexpression of Rab30 may be an early event in hepatocarcinogenesis. Further experiments were needed to determine the functional significance of Rab20/30 in HCC initiation and progression