DNA Damage Signals Induction of Fas Ligand in Tumor Cells

1999 ◽  
Vol 55 (2) ◽  
pp. 216-222 ◽  
Author(s):  
Yin-Yuan Mo ◽  
William T. Beck
Keyword(s):  
1999 ◽  
Vol 189 (8) ◽  
pp. 1285-1294 ◽  
Author(s):  
Laurie L. Hill ◽  
Vijay K. Shreedhar ◽  
Margaret L. Kripke ◽  
Laurie B. Owen-Schaub

Induction of antigen-specific suppression elicited by environmental insults, such as ultraviolet (UV)-B radiation in sunlight, can inhibit an effective immune response in vivo and may contribute to the outgrowth of UV-induced skin cancer. Although UV-induced DNA damage is known to be an initiating event in the immune suppression of most antigen responses, the underlying mechanism(s) of such suppression remain undefined. In this report, we document that Fas ligand (FasL) is critical for UV-induced systemic immune suppression. Normal mice acutely exposed to UV exhibit a profound suppression of both contact hypersensitivity and delayed type hypersensitivity (DTH) reactions and the development of transferable antigen-specific suppressor cells. FasL-deficient mice exposed to UV lack both transferable suppressor cell activity and primary suppression to all antigens tested, with the exception of the DTH response to allogeneic spleen cells. Interestingly, suppression of this response is also known to occur independently of UV-induced DNA damage. Delivery of alloantigen as protein, rather than intact cells, restored the requirement for FasL in UV-induced immune suppression of this response. These results substantiate that FasL/Fas interactions are essential for systemic UV-induced suppression of immune responses that involve host antigen presentation and suggest an interrelationship between UV-induced DNA damage and FasL in this phenomenon. Collectively, our results suggest a model whereby UV-induced DNA damage disarms the immune system in a manner similar to that observed in immunologically privileged sites.


Tumor Biology ◽  
2017 ◽  
Vol 39 (3) ◽  
pp. 101042831769501 ◽  
Author(s):  
Isha Rani ◽  
Bhoomika Sharma ◽  
Sandeep Kumar ◽  
Satinder Kaur ◽  
Navneet Agnihotri

5-Fluorouracil has been considered as a cornerstone therapy for colorectal cancer; however, it suffers from low therapeutic response rate and severe side effects. Therefore, there is an urgent need to increase the clinical efficacy of 5-fluorouracil. Recently, fish oil rich in n-3 polyunsaturated fatty acids has been reported to chemosensitize tumor cells to anti-cancer drugs. This study is designed to understand the underlying mechanisms of synergistic effect of fish oil and 5-fluorouracil by evaluation of tumor cell–associated markers such as apoptosis and DNA damage. The colon cancer was developed by administration of N,N-dimethylhydrazine dihydrochloride and dextran sulfate sodium salt. Further these animals were treated with 5-fluorouracil, fish oil, or a combination of both. In carcinogen-treated animals, a decrease in DNA damage and apoptotic index was observed. There was also a decrease in the expression of Fas, FasL, caspase 8, and Bax, and an increase in Bcl-2. In contrast, administration of 5-fluorouracil and fish oil as an adjuvant increased both DNA damage and apoptotic index by activation of both extrinsic and intrinsic apoptotic pathways as compared to the other groups. The increased pro-apoptotic effect by synergism of 5-fluorouracil and fish oil may be attributed to the incorporation of n-3 polyunsaturated fatty acids in membrane, which alters membrane fluidity in cancer cells. In conclusion, this study highlights that the induction of apoptotic pathway by fish oil may increase the susceptibility of tumors to chemotherapeutic regimens.


Viruses ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 393 ◽  
Author(s):  
Liqian Zhu ◽  
Xiaotian Fu ◽  
Chen Yuan ◽  
Xinyi Jiang ◽  
Gaiping Zhang

Bovine herpesvirus 1 (BoHV-1) is an important pathogen of cattle that causes lesions in mucosal surfaces, genital tracts and nervous systems. As a novel oncolytic virus, BoHV-1 infects and kills numerous human tumor cells. However, the mechanisms underlying the virus-induced cell damages are not fully understood. In this study, we demonstrated that virus infection of MDBK cells induced high levels of DNA damage, because the percentage of comet tail DNA (tailDNA%) determined by comet assay, a direct indicator of DNA damage, and the levels of 8-hydroxyguanine (8-oxoG) production, an oxidative DNA damage marker, consistently increased following the virus infection. The expression of 8-oxoguanine DNA glycosylase (OGG-1), an enzyme responsible for the excision of 8-oxoG, was significantly decreased due to the virus infection, which corroborated with the finding that BoHV-1 infection stimulated 8-oxoG production. Furthermore, the virus replication in human tumor cells such as in A549 cells and U2OS cells also induced DNA damage. Chemical inhibition of reactive oxidative species (ROS) production by either ROS scavenger N-Acetyl-l-cysteine or NOX inhibitor diphenylene iodonium (DPI) significantly decreased the levels of tailDNA%, suggesting the involvement of ROS in the virus induced DNA lesions. Collectively, these results indicated that BoHV-1 infection of these cells elicits oxidative DNA damages, providing a perspective in understanding the mechanisms by which the virus induces cell death in both native host cells and human tumor cells.


Blood ◽  
1998 ◽  
Vol 91 (11) ◽  
pp. 4273-4281 ◽  
Author(s):  
Inge Tinhofer ◽  
Ingrid Marschitz ◽  
Marion Kos ◽  
Traudl Henn ◽  
Alexander Egle ◽  
...  

Abstract B-chronic lymphocytic leukemia (B-CLL) is characterized by cellular and humoral immune defects resulting in increased rates of infection and disturbed immune surveillance against cancer cells as well as by the expansion of slowly proliferating tumor cells. We found increased Fas receptor (FasR) expression in peripheral blood CD4+and CD8+ cells of B-CLL patients compared with the equivalent cells of healthy donors. Although increased Fas receptor expression was significant in both T-lymphocytic subsets, only CD4+ cells from B-CLL patients underwent apoptosis after treatment with the agonistic Fas antibody CH11. In CD4+cells of B-CLL patients, the Fas-sensitivity also correlated with a CD4+/CD8+ ratio below the lower threshold of healthy individuals (<1.0). By contrast, FasR expression in the CD19+ fraction of B-CLL patients was downregulated compared with normal controls, and this was associated with an insensitivity to CH11-induced apoptosis. The B-CLL cell line EHEB as well as CD19+ cells from B-CLL patients constitutively expressed Fas ligand (FasL). The FasL was functionally active, as the B-CLL cell line as well as T-cell–depleted CD19+ B-CLL fractions were able to kill target T-acute lymphatic leukemia (T-ALL) cells in vitro. This effect was inhibited by the antagonistic FasR-antibody ZB4, the neutralizing anti-FasL monoclonal antibody (MoAb) NOK-2 or by transfection of the caspase inhibitor crmA. These data point to the fact that expression of FasL on CD19+B-CLL cells, together with enhanced susceptibility of CD4+ T cells toward FasL-bearing effector cells, are causally linked to the relative reduction of CD4+ cells occurring during B-CLL progression. These findings could explain the inversion of the ratio of CD4+/CD8+ cell numbers, which may be causally linked to the immune deficiency observed in these patients and to the expansion of the neoplastic clone in B-CLL.


2013 ◽  
Vol 33 (1) ◽  
pp. 3-13 ◽  
Author(s):  
SC Semprebon ◽  
 de Fátima ◽  
SR Lepri ◽  
D Sartori ◽  
LR Ribeiro ◽  
...  

(R)-Goniothalamin (R-GNT) is a secondary metabolite isolated from the plants of the genus Goniothalamus. This molecule has attracted the attention of researchers because of its selective cytotoxicity against tumor cells and its ability to induce apoptosis. (S)-Goniothalamin (S-GNT) is a synthetic enantiomer of R-GNT, and its mechanism of action is largely unknown. In this study, we investigated the activity of S-GNT in a human non-small cell lung cancer NCI-H460 cells. We observed that the cells exposed to this compound exhibited cytotoxicity in a concentration-dependent manner. Based on the data obtained through the assessment of apoptosis induction in situ and the comet assay, we suggest that this cytotoxicity occurs due to the potential ability of this molecule to induce DNA damage with the consequent induction of cell death via apoptosis. A significant reduction in the messenger RNA levels of baculoviral inhibitor of apoptosis repeat-containing 5 ( BIRC5) gene that encodes the survivin protein was found. This novel finding may explain the inhibition of cell proliferation and induction of apoptosis in tumor cells caused by this compound.


Author(s):  
Michael Glei ◽  
Stefanie Klenow ◽  
Julia Sauer ◽  
Uta Wegewitz ◽  
Konrad Richter ◽  
...  

2014 ◽  
Vol 97 (1) ◽  
pp. 379-380 ◽  
Author(s):  
Heriberto Prado-Garcia ◽  
Susana Romero-Garcia ◽  
Jose Sullivan Lopez-Gonzalez

2014 ◽  
Vol 7 (4) ◽  
pp. 1083-1087 ◽  
Author(s):  
JIANGUO LI ◽  
YAN WANG ◽  
LIQING DU ◽  
CHANG XU ◽  
JIA CAO ◽  
...  

2013 ◽  
Vol 288 (23) ◽  
pp. 16212-16224 ◽  
Author(s):  
Elvira Crescenzi ◽  
Zelinda Raia ◽  
Francesco Pacifico ◽  
Stefano Mellone ◽  
Fortunato Moscato ◽  
...  

Premature or drug-induced senescence is a major cellular response to chemotherapy in solid tumors. The senescent phenotype develops slowly and is associated with chronic DNA damage response. We found that expression of wild-type p53-induced phosphatase 1 (Wip1) is markedly down-regulated during persistent DNA damage and after drug release during the acquisition of the senescent phenotype in carcinoma cells. We demonstrate that down-regulation of Wip1 is required for maintenance of permanent G2 arrest. In fact, we show that forced expression of Wip1 in premature senescent tumor cells induces inappropriate re-initiation of mitosis, uncontrolled polyploid progression, and cell death by mitotic failure. Most of the effects of Wip1 may be attributed to its ability to dephosphorylate p53 at Ser15 and to inhibit DNA damage response. However, we also uncover a regulatory pathway whereby suppression of p53 Ser15 phosphorylation is associated with enhanced phosphorylation at Ser46, increased p53 protein levels, and induction of Noxa expression. On the whole, our data indicate that down-regulation of Wip1 expression during premature senescence plays a pivotal role in regulating several p53-dependent aspects of the senescent phenotype.


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