The involvement of nuclear factor-kappa B in cyclooxygenase-2 overexpression in murine colon cancer cells transduced with herpes simplex virus thymidine kinase gene (original) (raw)
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Cancer Gene Therapy, 2004
Transduction of tumor cells with herpes simplex virus thymidine kinase (HSV-tk) gene and subsequent treatment with the prodrug ganciclovir (GCV) is the most common system utilized to date for ''suicide'' gene therapy of cancer. In the current report, we show that HSV-tk gene transduction enhances tumor growth rate of murine colon cancer cells, that are implanted subcutaneously in syngeneic mice, and enhances cyclooxygenase-2 (COX-2) protein expression and prostaglandin E 2 (PGE 2 ) release in vitro and in vivo. It is further shown that the observed phenomenon is related to the presence of the HSV-tk sequence insert in the retroviral vector used for HSV-tk gene delivery. Transduction of murine colon cancer cells with control vector, carrying the neomycinresistance gene alone, failed to increase tumor growth rate and COX-2 protein expression or PGE 2 production. On the contrary, it even decreased tumor growth, COX-2 protein expression and PGE 2. The growth rate of HSV-tk-transduced murine tumors was significantly reduced by treatment with the selective COX-2 inhibitor nimesulide. Additionally, we demonstrate herein that both enhanced growth rate of HSV-tk-transduced murine tumors and increased levels of PGE 2 in HSV-tk-transduced cells persist upon the development of GCV resistance. Taken together, these results provide a better understanding of the direct effect of HSV-tk gene transduction on tumor cell biology and target tumor development.
Tumorigenesis and Aberrant Signaling in Transgenic Mice Expressing the Human Herpesvirus-8 K1 Gene
CancerSpectrum Knowledge Environment, 2002
Background: The K1 gene of human herpesvirus-8 (HHV-8; also known as Kaposi's sarcoma-associated herpesvirus) encodes a transmembrane signaling protein that elicits cellular activation events. To evaluate the potential role of K1 in HHV-8-associated pathogenesis, we produced transgenic mice expressing the HHV-8 K1 gene under the transcriptional control of the simian virus 40 promoter. Methods: Three independent heterozygous transgenic K1 mouse lines were generated from founder mice. Mouse splenic and thymic lymphocytes and tumor tissues were analyzed for the expression of cytokines involved in inflammatory and immune responses, including tumor necrosis factor-␣ (TNF-␣), interleukin 6 (IL-6), basic fibroblast growth factor (bFGF), and interleukin 12 (IL-12); for the activation of the transcription factors nuclear factor-B (NF-B) and the B cellspecific transcription factor Oct-2; and for the activation of the Src and Syk family kinases, components of B-cell receptor-induced signal-transduction pathways. Results: Expression of bFGF was increased in K1-transgenic mice as compared with nontransgenic mice, whereas expression of TNF-␣ and IL-6 did not differ using reverse transcriptasepolymerase chain reaction. K1-transgenic mice showed substantially less serum IL-12 induction than did nontransgenic mice when challenged with a lipopolysaccharide. B lymphocytes from K1-transgenic mice but not from nontransgenic mice showed constitutive activation of NF-B and Oct-2. K1 expression in human B lymphocytes stimulated NF-B-dependent promoter activity. B lymphocytes from K1-transgenic mice also showed increased phosphorylation of Lyn, a Src family tyrosine kinase, and enhanced Lyn activity. Tumors in K1-transgenic mice showed features indicative of a spindle-cell sarcomatoid tumor and a malignant plasmablastic lymphoma. The pattern of cytokine, transcription factor, and Lyn kinase activity in the lymphoma was similar to that in B lymphocytes from K1-transgenic mice. Conclusion: K1 may be involved in the activation of NF-B signaling. The enhanced NF-B activity in nonmalignant lymphocytes of K1 mice and its persistence in lymphoma tumors of these mice suggest that the K1 mouse may be a model of premalignancy. [J Natl Cancer Inst 2002;94: 926-35]
NF-kappaB is essential for the progression of KSHV- and EBV-infected lymphomas in vivo
Blood, 2006
Activated NF-kappaB is a critical mechanism by which lymphoma cells infected by Epstein-Barr virus (EBV/HHV-4) and Kaposi sarcoma herpesvirus (KSHV/HHV-8) are protected from apoptotic stress. Selective pharmacologic inhibition of constitutive NF-kappaB activity induces apoptosis in KSHV- and EBV-infected lymphoma cells. In both tumor types, pharmacologic inhibition of NF-kappaB in vitro induced identical mitochondrially mediated apoptosis cascades. Assessment of gene regulation by microarray analysis revealed that the inhibition of NF-kappaB in tumor cells results in the down-regulation of a distinct group of prosurvival genes, including cIAP-1, cIAP-2, cFLIP, and IL-6. Using EBV- and KSHV-associated lymphomas in a murine system, we demonstrated that Bay 11-7082, a selective pharmacologic inhibitor of NF-kappaB, prevents or delays tumor growth and prolongs disease-free survival. Inhibition of NF-kappaB activity and tumor growth responses were further documented using a traceable rep...
JNCI Monographs, 2000
Background: The growing number of human immunodeficiency virus type 1 (HIV-1) infections worldwide and the increasing use of immunosuppressive modalities for organ transplantation have contributed to an epidemic of Kaposi's sarcoma (KS), which has been etiologically linked to human herpesvirus 8 (HHV8) or KS-associated virus. Since the onset of the acquired immunodeficiency syndrome epidemic, inflammation has been recognized as an essential component of KS pathology. HHV8 bears a gene (K1) encoding a transmembrane protein with an immunoreceptor tyrosine-based activation motif. This motif is present in receptors that mediate inflammation. Purpose: To dissect the cellular effects of K1 function and the eventual role of K1 in KS, we developed a cell model for studying K1 expression.
Journal of virology, 2014
Kaposi's sarcoma herpesvirus (KSHV) (or human herpesvirus 8) is the cause of Kaposi's sarcoma, primary effusion lymphoma (PEL), and the plasma cell variant of multicentric Castleman's disease (MCD). The transmembrane K15 protein, encoded by KSHV, has been shown to activate NF-κB and the mitogen-activated protein kinases (MAPKs) c-jun-N-terminal kinase (JNK) and extracellular signal-regulated kinase (Erk) as well as phospholipase C gamma (PLCγ) and to contribute to KSHV-induced angiogenesis. Here we investigate how the K15 protein activates the NF-κB pathway. We show that activation of NF-κB involves the recruitment of NF-κB-inducing kinase (NIK) and IKK α/β to result in the phosphorylation of p65/RelA on Ser536. A K15 mutant devoid in NIK/IKK recruitment fails to activate NF-κB but remains proficient in the stimulation of both NFAT- and AP1-dependent promoters, showing that the structural integrity of the mutant K15 protein has not been altered dramatically. Direct recru...
NKG2D ligands are cell surface proteins that activate NKG2D, a receptor used by natural killer (NK) cells to detect virus-infected and transformed cells. When tumour cells express high levels of NKG2D ligands, they are rejected by the immune system. Hence, reagents that increase NKG2D ligand expression on tumour cells can be important for tumour immunotherapy. To identify genes that regulate the NKG2D ligand H60a, we performed a microarray analysis of 3′-methylcholanthrene-induced sarcoma cell lines expressing high versus low H60a levels. A20, an inhibitor of nuclear factor-κB (NF-κB) activation, was differentially expressed in H60a-hi sarcoma cells. Correspondingly, treatment of tumour cells with inhibitors of NF-κB activation, such as sulfasalazine (slz), BAY-11-7085, or a non-phosphorylatable IκB, led to increased levels of H60a protein, whereas transduction of cells with an active form of IκB kinase-β (IKKβ) led to decreased levels of H60a. The regulation probably occurred at the transcriptional level, because NF-κB pathway inhibition led to increased H60a transcripts and promoter activity. Moreover, treatment of tumour cells with slz enhanced their killing by NK cells in vitro, suggesting that NF-κB inhibition can lead to tumour cell rejection. Indeed, when we blocked the NF-κB pathway specifically in tumour cells, there was decreased tumour growth in wild-type but not immune-deficient mice. Our results suggest that reagents that can block NF-κB activity specifically in the tumour and not the host immune cells would be efficacious for tumour therapy.
Human Gene Therapy, 2006
Activation of nuclear factor-B (NF-B) can promote or inhibit apoptosis. Oxidative stress is an important mechanism by which certain anticancer drugs kill cancer cells, and is also one of the mechanisms that activate NF-B. We therefore examined hepatic expression of the NF-B monomer p65 in human hepatocellular carcinoma (HCC) tissue samples from eight patients and compared it with their respective samples of surrounding liver tissues. We also studied the effect of NF-B inhibition in human HCC cells exposed to oxidative stress, by infecting HuH7 cells with a recombinant adenovirus carrying mutant IB␣ (mIB␣). Cultured HuH7 cells were infected with mIB␣ or -galactosidase (-Gal) for 24 hr followed by treatment with increasing concentrations of H 2 O 2. Cytotoxicity, NF-B translocation, NF-B DNA binding, cell proliferation, and apoptosis were determined. The monomer p65 was overexpressed in six of eight human HCC tissues. In HuH7 cells, introduction of mIB␣ potently inhibited the translocation, activation, and DNA binding of NF-B. In control (-Gal-infected) HuH7 cells, exposure to H 2 O 2 produced a dose-dependent increase in apoptosis, regardless of NF-B status. mIB␣-mediated inhibition of NF-B activation sensitized HuH7 cells to H 2 O 2-induced inhibition of cell growth, and further promoted cell death. Addition of H 2 O 2 (200-500 M) to control or mIB␣-infected HuH7 cells enhanced caspase-3 activity and cleavage. Adenovirus-mediated transfer of mIB␣ potently inhibits NF-B activity in HuH7 cells, and this enhances oxidative stress-induced cell killing.