Publications by authors named "Teppei Onishi"

"Cell-in-cell" denotes an invasive phenotype in which one cell actively internalizes in another. The novel human T-cell line HOZOT, established from human umbilical cord blood, was shown to penetrate a variety of human cancer cells but not normal cells. Oncolytic viruses are emerging as biological therapies for human cancers; however, efficient viral delivery is limited by a lack of tumor-specific homing and presence of pre-existing or therapy-induced neutralizing antibodies.

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Tumor suppressor p53 is a multifunctional transcription factor that regulates diverse cell fates, including apoptosis and autophagy in tumor biology. p53 overexpression enhances the antitumor activity of oncolytic adenoviruses; however, the molecular mechanism of this occurrence remains unclear. We previously developed a tumor-specific replication-competent oncolytic adenovirus, OBP-301, that kills human osteosarcoma cells, but some human osteosarcoma cells were OBP-301-resistant.

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Autophagy is known to have a cytoprotective role under various cellular stresses; however, it also results in robust cell death as an important safeguard mechanism that protects the organism against invading pathogens and unwanted cancer cells. Autophagy is regulated by cell signalling including microRNA (miRNA), a post-transcriptional regulator of gene expression. Here, we show that genetically engineered telomerase-specific oncolytic adenovirus induced miR-7 expression, which is significantly associated with its cytopathic activity in human cancer cells.

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Trastuzumab, a humanized antibody targeting HER2, exhibits remarkable therapeutic efficacy against HER2-positive breast and gastric cancers; however, acquired resistance presents a formidable obstacle to long-term tumor responses in the majority of patients. Here, we show the mechanism of resistance to trastuzumab in HER2-positive human cancer cells and explore the molecular sensitization by exogenous expression of HER2-extracellular domain (ECD) in HER2-negative or trastuzumab-resistant human cancer cells. We found that long-term exposure to trastuzumab induced resistance in HER2-positive cancer cells; HER2 expression was downregulated, and antibody-dependent cellular cytotoxicity (ADCC) activity was impaired.

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Purpose: The combination of hepatitis B immunoglobulin (HBIg) and nucleos(t)ide analogues has been accepted as the best treatment to control hepatitis B recurrence after orthotopic liver transplantation (OLT). However, the optimal dose of HBIg remains unclear. We have previously reported that high-dose HBIg in the early period followed by low-dose HBIg with nucleos(t)ide analogues offers reliable and cost-effective control of hepatitis B recurrence.

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Background/purpose: We present the cases of two patients with hepatocellular carcinoma (HCC) beyond the Milan criteria (MC) who underwent living-donor liver transplantation (LDLT) combined with aggressive hepatic venacaval resection and replacement of the hepatic inferior vena cava (IVC) by an artificial vascular graft. The aim of the resection and replacement of the hepatic IVC was to resect completely a latent cancer adjacent to the hepatic IVC and to avoid micrometastasis via the hepatic veins during increased manipulation of the native liver with HCC.

Methods: First, the hepatic hilus was dissected and the infrahepatic IVC was encircled.

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