The Chinese hamster embryo fibroblast cell line CHEF/18 is readily transfected by plasmid DNA. In the present transfection studies with CHEF/18 cells, focus formation induced by plasmids containing the mutant human c-Ha-ras gene EJ was compared with that of control plasmids without the EJ insert. The focus-forming activity of the transfected plasmid J132, a recombinant of the Harvey murine sarcoma virus LTR and the normal human c-Ha-ras1 in pBR322, also was assessed. Foci were recovered after transfection with either pSV2gpt or pSV2neo at about 10% the frequency obtained with the EJ-containing plasmids, and J132 gave a similar frequency, all well above background obtained with salmon sperm DNA. Whereas foci from transfection with EJ-containing plasmids contained the EJ DNA, no plasmid DNA was detected in either tumorigenic or tumor-derived cells from foci transfected with pSVgpt, pSVneo, or J132. Evidence that genomic changes were induced by plasmid transfection is based on finding chromosomal aberrations in all expanded foci and tumor-derived cells examined. The results suggest the occurrence of "hit-and-run" tumorigenesis induced by transient plasmid transfection.
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http://dx.doi.org/10.1073/pnas.82.9.2839 | DOI Listing |
Int J Biochem Cell Biol
April 2024
Department of Medical Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Electronic address:
The crucial role of high mobility group AT-hook 1 (HMGA1) proteins in nuclear processes such as gene transcription, DNA replication, and chromatin remodeling is undeniable. Elevated levels of HMGA1 have been associated with unfavorable clinical outcomes and adverse differentiation status across various cancer types. HMGA1 regulates a diverse array of biological pathways, including tumor necrosis factor-alpha/nuclear factor-kappa B (TNF-α/NF-κB), epidermal growth factor receptor (EGFR), Hippo, Rat sarcoma/extracellular signal-regulated kinase (Ras/ERK), protein kinase B (Akt), wingless-related integration site/beta-catenin (Wnt/beta-catenin), and phosphoinositide 3-kinase/protein kinase B (PI3-K/Akt).
View Article and Find Full Text PDFCurr Top Microbiol Immunol
January 2024
Institute of Microbial Chemistry, Laboratory of Microbial Carcinogenesis, Microbial Chemistry Research Foundation, 3-14-23 Kamiosaki, Shinagawa-Ku, Tokyo, 141-0021, Japan.
Helicobacter pylori CagA is the first and only bacterial oncoprotein etiologically associated with human cancer. Upon delivery into gastric epithelial cells via bacterial type IV secretion, CagA acts as a pathogenic/pro-oncogenic scaffold that interacts with and functionally perturbs multiple host proteins such as pro-oncogenic SHP2 phosphatase and polarity-regulating kinase PAR1b/MARK2. Although H.
View Article and Find Full Text PDFFuture Oncol
February 2023
Medical Oncology Unit, Fondazione IRCCS Policlinico San Matteo, Viale Camillo Golgi 19, Pavia, 27100, Italy.
J Pathol
June 2023
Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Epstein-Barr virus (EBV) is one of the major drivers of gastric carcinogenesis. EBV infection is established before tumour initiation and is generally maintained throughout tumour development; however, the significance of EBV in tumour maintenance and progression remains to be elucidated. Here, we report eight cases of EBV-associated gastric carcinoma (EBVaGC) with intratumoural heterogenous expression of EBV-encoded small RNA (EBER), a highly expressed latent gene of EBV, and demonstrate clinicopathological characteristics of these rare cases.
View Article and Find Full Text PDFPathogens
December 2022
Clinic of Gynecology and Obstetrics, Jessenius Faculty of Medicine, Comenius University in Bratislava, 03601 Martin, Slovakia.
Some estimates place the proportion of human malignancies attributable to viruses at between 15 and 20 percent. Viruses including the human papillomavirus are considered an interesting but controversial etiological risk factor for breast cancer. HPV infection is anticipated to be an early trigger in breast cancer carcinogenesis, followed by cumulative alterations over time ("hit and run" mechanism) through synergy with other environmental factors.
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