Although hepatitis C virus (HCV) mainly affects hepatocytes, infection is widespread and involves immunologically privileged sites. Whether lymphoid cells represent further targets of early HCV infection, or whether other cells in the hematopoietic microenvironment may serve as a potential virus reservoir, is still unclear. We studied whether pluripotent hematopoietic CD34+ cells support productive HCV infection and can be used to establish an in vitro infection system for HCV. Six patients were selected as part of a cohort of HCV chronic carriers who developed a neoplastic disease. Reverse transcriptase-polymerase chain reaction (RT-PCR) and branched DNA signal amplification assays were used to detect and quantitate HCV RNA in extracted nucleic acids from purified bone marrow and peripheral blood CD34+ cells. Direct in situ RT-PCR, flow cytometry analysis, and immunocytochemistry were applied to demonstrate specific viral genomic sequences and structural and nonstructural virus-related proteins in intact cells. Results indicated that both positive and negative HCV RNA strands and viral proteins were present in CD34+ cells from all HCV-positive patients and in none of the controls. Additional experiments showed that a complete viral cycle took place in CD34+ cells in vitro. Spontaneous increases in viral titers indicated that virions were produced by infected hematopoietic progenitor cells. To further define the cellular tropism, we attempted to infect CD34+ cells in vitro. We were unable to demonstrate viral uptake by cells. These findings suggest that HCV replication can occur in the early differentiation stages of hematopoietic progenitor cells, and that they may be an important source of virus production. © 1998 by The American Society of Hematology.
Gastric cancer (GC) is characterized by extreme heterogeneity due to histopathological differences, molecular characteristics, and immune gene expression signature. Until recently, several targeted therapies failed due to this complexity. The recent immunotherapy resulted in more effective and safe approaches in several malignancies. All tumors could be considered potentially immunogenic and the new knowledge regarding the interactions among tumor cells, immune cells, and tumor microenvironment (TME) allowed to reverse possible immune resistance. The immune response is a complex multisteps process that finely regulates the balance between the recognition of non-self and the prevention of autoimmunity. Cancer cells can use these pathways to suppress tumor immunity as a major mechanism of immune resistance. The recent molecular classifications of GCs by The Cancer Genome Atlas (TCGA) and by the Asian Cancer Research (ACRG) networks, together with the identification of multiple biomarkers, open new perspectives for stratification of patients who might benefit from a long-term immune checkpoint therapy. One of the major processes that contribute to an immunosuppressive microenvironment is represented by tumor angiogenesis. The cellular mechanisms inducing both angiogenesis and immunosuppressive responses are often reached by the same cell types and soluble factors, such as vascular endothelial growth factor A (VEGFA). Recent studies point out that combinatorial strategies should be adapted as useful therapeutic approach to reverse the immunosuppressive status of microenvironment occurring in a relevant percentage of gastric tumors.
Extracellular vesicles (EVs) are involved in intercellular communication during the carcinogenesis. Our attention has been focused on small EVs (sEVs) protein content in colorectal and gastric cancer (CRC and GC). Frizzled (FZD) proteins, a family of receptors comprised in the Wnt signaling pathway, play an important role in the carcinogenesis of CRC and GC. Here, the expression of a specific FZD protein, namely, FZD-10, was investigated in the sEVs extracted from plasma of patients affected by CRC and GC as involved in canonical and noncanonical Wnt signaling in cancer stem cells with a subsequent modification of cellular heterogeneity, omics reprogramming, and tumor plasticity. The expression of FZD-10 protein in the sEVs extracted from plasma of patients affected by CRC and GC and sEVs from plasma of healthy subjects was evaluated against the level of protein Hsp70, established as EVs specific markers along with CD63 and ALIX proteins. The FZD-10 extract from sEVs isolated from plasma of the controls and the CRC or GC subjects indicated that its expression in oncological patients was higher than in the control group, while, at the end of the treatment, it reached values comparable with the average level of controls. Furthermore, the level of FZD-10 in the whole plasma was found comparable with its level in the sEVs extract. The level of FZD-10 in the sEVs represents a potential reliable biomarker with a valuable prognostic function for the diagnosis of CRC and GC and for monitoring the treatment response.
High LDH and FBG levels correlated with prognosis. A significant correlation between bevacizumab-based chemotherapy-induced reduction in LDH serum levels and response to treatment was observed within the high LDH group. These results, if confirmed in larger prospective studies, could be helpful for early identification of patients responsive to bevacizumab-based chemotherapy or candidate to more aggressive treatments.
Ramucirumab is approved both as monotherapy and in combination with paclitaxel for advanced gastric cancer in patients with disease progression after chemotherapy. in tumor cells, the VeGfA-VEGFR2 binding activates autocrine survival and migration signaling in angiogenesis independent manner. the present in vitro study investigated the effects of single and combined treatments with Ramucirumab and paclitaxel on cell growth and migration highlighting the mechanisms underlying the interaction between the two drugs in gastric cancer cells. cell growth and motility were investigated in human gastric cancer cell lines characterized by different tumorigenicity. The inhibitory effect on cell growth exerted by both drugs was potentiated by their combination and was synergistic. Ramucirumab was able to enhance the inhibitory effect exerted by Paclitaxel on cell cycle progression. A synergistic action was also observed in the expression of proteins crucial for cell motility, microtubule organization and epithelial-mesenchymal transition. Furthermore, synergistic inhibition of VEGFR2 expression was obtained by the drug combination. These findings highlighted the importance of the combined treatment to strongly inhibit all the main molecules of both PI3K/Akt/mTOR and MAPK pathways thus preventing possible reactivations due to cross-talk phenomena. The combined treatment with Ramucirumab seems to be a promising option to overcome the paclitaxel resistance.VEGFR2 plays a crucial role in gastric cancer pathogenesis and progression and Ramucirumab (Ram), a monoclonal antibody against VEGFR2, is the first antiangiogenic agent with demonstrated activity against advanced gastric cancer. Based on the results obtained by two different phase III studies, Ram is approved both as monotherapy and in combination with Paclitaxel (PTX) for this malignancy in patients with disease in progression after a preceding therapy based on platinum and fluoropyrimidin 1-5 .The proangiogenic actions of VEGFs in endothelial cells are mediated primarily through the binding and activation of VEGFR2 6 and retrospective studies considered VEGF and its receptors as possible biomarkers in gastric carcinoma 7-9 . Moreover, the recent discovery of the production of different VEGF ligands and of the expression of VEGFR1, VEGFR2 and VEGFR3 in epithelial cancer cells, suggests a direct role for these ligands and their receptors in the autocrine control of some biological processes. In epithelial tumor cells, the binding of VEGFA, the main ligand of VEGFR2, activates downstream survival and migration signaling pathways represented by PI3K/ Akt/mTOR and MAPK cascades in a cell autonomous and angiogenesis independent manner 10-13 .The combined treatment with Ram seems to be a promising option to prevent the resistance to PTX also in recurrent and metastatic gastric cancer patients receiving taxane-based first-line palliative chemotherapy 14 . PTX is known to interfere with microtubule architecture by binding to β-tubulin, thereby blocking cell cycle progression at th...
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