Interaction of viruses with tumor promotors

Yamamoto, Naoki

doi:10.1007/bfb0027695

Cited by 14 publications

(4 citation statements)

References 192 publications

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“…From this result the authors concluded that HTLV not only immortalizes but also malignantly transforms rat T-cells in vitro. This observation may be important in considering the role of HTLV in ATL leukaemogenesis in relation to a multi-step carcinogenesis model (Yamamoto, 1984).…”

Section: Experimental Infection Of Animals With Htl V[a Tl Vmentioning

confidence: 86%

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Viral Aetiology of Adult T-Cell Leukaemia

Yamamoto

Hinuma

1985

Journal of General Virology

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Section: Experimental Infection Of Animals With Htl V[a Tl Vmentioning

confidence: 86%

“…Such factors can be assumed to be both exogenous and endogenous. It appears to us that ATL carcinogenesis results from the interaction of HTLV/ATLV with various biological, physical and chemical factors in the environment (Yamamoto, 1984).…”

Section: Overall Conclusionmentioning

confidence: 99%

Viral Aetiology of Adult T-Cell Leukaemia

Yamamoto

Hinuma

1985

Journal of General Virology

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“…3) correlate well with their capabilities to induce in NC37 and Raji cells early antigen of EBV (Table 8). Most recently it was shown that also some of the new indole alkaloid type promoters (see above) induce EBV synthesis in much the same way as TPA (Yamamoto, 1984;Yamamoto et al, 1981). To what extent these findings may be generalized for all structural types of tumour promoters (Takada & zur Hausen, 1984) remains to be seen.…”

Section: Cancer Of the Nasopharynx In South China-another Aetiolou Ofmentioning

confidence: 95%

Tumour promoters of the irritant diterpene ester type as risk factors of cancer in man

Hecker

1987

Botanical Journal of the Linnean Society

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Tumour promoters of the irritant diterpene ester type as risk factors of cancer in man. It is widely accepted in experimental and epidemiologic oncology that in real human life multifactorial causation of cancer is the rule and classical unifactorial causation the exception. This current and comprehensive concept of the aetiology of cancer has evolved essentially from in‐depth investigations of tumour promoters of the irritant DTE type, found occurring in the Euphorbiales (Euphorbiaceae, Thymelaeaceae) in about the last 20 years. Moreover, the irritant DTEs are most powerful tools in experimental cell and cancer research, as illustrated by current results of investigations of their toxicokinetics and toxicodynamics. Quantitative chemical and toxicologic investigations indicate that life‐style oesophageal cancer, prevalent on Curasao, is the first case of cocarcinogens of the DTE type (‘Welensalifactors’ from Croton flavens L.) shown to be the principal risk factor in a multifactorial human cancer, in conjunction with initiators of the solitary carcinogenic PAH type. The typical tigliane type DTE Welensalifactor F, was isolated, also from the tung oil tree (Aleuritesfordii). It was shown that DTEs of the tigliane, ingenane and daphnane types activate certain human tumour viruses, e.g. the Epstein‐Barr virus. The latter virus is known to be associated with nasopharyngeal carcinoma (NPC) prevalent in South China. It is concluded that uncontrolled utilization of Euphorbiaceae‐derived materials, e.g. as (ethno‐medicinal) drugs, or as technological raw materials, may be responsible for high incidence rates of certain human cancers due to DTE type risk factors of the promoter type. The identification of well defined cocarcinogens of the DTE type as a new, non‐classical group of risk factors in terms of ‘per se essentially non‐carcinogenic amplifiers’ of carcinogenesis adds a new dimension to the aetiology of cancer in man. Together with the multifactorial concept of carcinogenesis, it may allow a more refined assessment of the cancer risk.

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“…In certain cells TPA may inhibit or stimulate differentiation, stimulate DNA synthesis, induce the production of various growth factors, hormones and other cellular secretions and induce proto-oncogenes (Yamamoto, 1984). TPA has been used in virus systems to enhance human immunodeficiency virus (HIV) replication in MT-4 ceils (Harada et al, 1986), to stimulate transcription from the simian virus 40 enhancer (Chiu et al, 1987) and to induce Epstein-Barr virus (EBV) replication in producer lymphoblastoid cell lines (zur Hausen et al, 1978;Laux et al, 1988).…”

mentioning

confidence: 99%

The Effects of 5-Azacytidine, 12-O-Tetradecanoylphorbol 13-acetate and Sodium n-butyrate on Reactivation of Alphaherpesvirus Saimiri from Explant Cultures of Latently Infected Rabbit Dorsal Root Ganglia

Mossman

Leib²,

McCarthy

1989

Journal of General Virology

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SUMMARYThe DNA hypomethylating agent 5-azacytidine greatly increased the reactivation of alphaherpesvirus saimiri-1 (~tHVS) from latently infected rabbit dorsal root ganglia, although it inhibited the virus yield and plaque formation efficiency of ~HVS in Veto cells. 12-O-Tetradecanoylphorbol 13-acetate (a protein kinase C activator) and sodium n-butyrate both had a stimulating action on replication in Vero cells but did not affect the release of ctHVS from latently infected rabbit dorsal root ganglia.Two isolates of alphaherpesvirus saimiri (c~HVS) (formerly herpesvirus tamarinus) have been shown to produce fatal encephalitis (KM91) (Leib et al., 1988) or to establish latency (KM322) in dorsal root ganglia (DRGs) (Tosolini et al., 1982) when injected intradermally into rabbits. These isolates are very closely related in terms of restriction endonuclease digest patterns, polypeptide immunoprecipitation and growth characteristics (Leib et al., 1987). Intradermal inoculation of rabbits in the flank with ~HVS KM322 produces an initial skin lesion followed by ganglionitis as manifested by areas of hypoaesthesia (Tosolini et al., 1982). This is followed by a period of prolonged latency during which spontaneous reactivation has never been observed (Tosolini et al., 1981) although virus can be recovered by cocultivation of DRGs with a monolayer of permissive cells. However a very low proportion of ganglia serving the inoculated dermatomes yield reactivating virus by cocultivation (< 20 %), thus necessitating the sacrifice of a high number of rabbits to produce statistically significant results. In order to improve the sensitivity of detection of latent virus a number of agents known to stimulate other virus systems were incorporated into explant culture media. Since the molecular mechanisms involved in maintaining the latent state and in triggering reactivation are ill understood the agents used were selected for their different modes of action.5-Azacytidine (5-AzaC) is a DNA hypomethylating agent. The level of methylation of cytosine in CpG dinucleotides in DNA has been implicated as a means of cellular and viral gene control in a number of systems (reviewed by Doerfler, 1983). Generally a high degree of DNA methylation correlates with gene inactivation whereas low levels of methylation are associated with active parts of the genome. Inverse correlations between DNA methylation and gene expression have been observed in a number of virus replication systems including those of herpesviruses. In an in vitro latency system Youssoufian et al. (1982) showed latent herpes simplex virus type 1 (HSV-1) DNA to be extensively methylated, but this was not the case in actively replicating virus. In gammaherpesvirus saimiri (a virus not closely related to ~HVS) DNA is methylated in non-producing lymphoid cell lines but not in producing lines (Desrosiers et al., 1979). Also, the experimental induction of a previously inactive thymidine kinase gene in HSV-I is associated with concurrent demethylation of the gene promoter (Clough et ...

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Interaction of viruses with tumor promotors

Cited by 14 publications

References 192 publications

Viral Aetiology of Adult T-Cell Leukaemia

Viral Aetiology of Adult T-Cell Leukaemia

Tumour promoters of the irritant diterpene ester type as risk factors of cancer in man

The Effects of 5-Azacytidine, 12-O-Tetradecanoylphorbol 13-acetate and Sodium n-butyrate on Reactivation of Alphaherpesvirus Saimiri from Explant Cultures of Latently Infected Rabbit Dorsal Root Ganglia

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