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B G Pogo - One of the best experts on this subject based on the ideXlab platform.

  • detection of murine mammary tumor virus mmtv Env Gene like sequences in breast cancer from argentine patients
    Medicina-buenos Aires, 2002
    Co-Authors: S Melana, J F Holland, Maria Alejandra Picconi, Carlos Rossi, Juan Mural, Lidia Virginia Alonio, Angelica Teyssie, B G Pogo
    Abstract:

    In the last years research on the possible viral etiology of human breast cancer has been revised. Previous studies have demonstrated the presence of a Mouse Mammary Tumor Virus (MMTV) Env Gene-like sequence in about 38% of breast cancers from American and Italian women; these sequences are Generally absent in other tumors and in normal mammary tissue. In the present study we have analyzed the presence of a 250-bp sequence of the MMTV Env Gene in breast cancer biopsies from Argentine patients. The retroviral fragment was present in 31% (23/74) of the tumors, only in one normal mammary tissue and in none of the fibroadenomas analYzed. Peripheral blood mononuclear cells (PBMC) from 46 cancer patients were also analyzed; the sequence was found in 17% (2/12) of the PBMC from Env positive tumor patients and in 3% (1/34) of the Env negatives. The results from Argentine samples are similar to those from USA and Italy, where the breast cancer incidence is alike. These findings support the hypothesis of a viral agent involved in the Genesis of this neoplasia and encourage the continuation of these studies.

  • MMTV-like Env Gene sequences in human breast cancer.
    Archives of virology, 2001
    Co-Authors: Y Wang, J F Holland, S Melana, I Pelisson, B G Pogo
    Abstract:

    We have previously detected an MMTV Env Gene-like 660 bp sequence in 38% of human breast cancers, but not in normal tissues or other tumors. In this communication we report the sequences from eleven tumors and three breast cancer cell lines, and compare them to four strains of MMTV and to the known endogenous retroviral sequences. The breast cancer sequences were highly homogenous to the MMTV’s, but not to the endogenous sequences suggesting an exogenous origin.

  • Sequences homologous to the mouse mammary tumor virus Env Gene in human breast carcinoma correlate with overexpression of laminin receptor.
    Clinical cancer research : an official journal of the American Association for Cancer Research, 1999
    Co-Authors: B G Pogo, J F Holland, S Melana, John F. Mandeli, Silvana Pilotti, Patrizia Casalini, Sylvie Ménard
    Abstract:

    We previously reported that a 660-bp sequence that is homologous to the Env Gene of the mouse mammary tumor virus (MMTV) but not to endogenous retroviruses or to other known Genes was present in 38% of human breast cancers and in some breast cancer cell lines studied (Y. Wang et al. , Cancer Res., 55: 5173–5179, 1995). Here, we have investigated whether the MMTV-like sequences were associated with the clinical, pathological, and molecular parameters that have been reported to define two subsets of human breast cancers. Archival breast carcinoma samples were analyzed for four clinical parameters, obtained from patients’ records, and for six pathological characteristics. Expression of c-erbB-2, p53, bcl-2, progesterone receptor, laminin receptor, and cathepsin D was detected by immunochemistry using monoclonal antibodies. PCRs were used to amplify 250 bp of the MMTV Env Gene-like sequence. The χ 2 , log-rank, and Generalized Wilcoxon tests were used to analyze the data. The MMTV Env Gene-like sequence was detected in 37.7% of the samples. The presence of this sequence was not significantly associated with any of the pathological clinical or biological parameters studied. It did correlate, however, with expression of the laminin receptor, a marker for invasiveness and poor prognosis. This is the first phenotypic characterization of human breast cancers containing retroviral sequences.

  • expression of mouse mammary tumor virus like Env Gene sequences in human breast cancer
    Clinical Cancer Research, 1998
    Co-Authors: Y Wang, J F Holland, S Melana, B G Pogo
    Abstract:

    We have reported previously (Wang et al, Cancer Res., 55: 5173-5179, 1995) the presence of a 660-bp sequence that is 90-98% homologous to the Env Gene of mouse mammary tumor virus in 38% of 314 unselected breast cancer samples, in some breast cancer cell lines, and in 1.8% of the 107 normal breast specimens from reduction mammoplasties. In this communication, we have investigated whether the 660-bp sequence or a smaller 256-bp sequence within the 660 bp were expressed in breast tumors, normal breasts, and breast cancer cell lines by means of reverse transcription-PCR. The results indicated that expression of the 660-bp sequence was detected in 66% of the sequence-positive breast tumors studied and in none of the negative tumors or normal breasts and that the 256-bp sequence was expressed in all of the Env-positive breast cancer cell lines tested. Sequence analysis revealed that the expressed 660-bp sequence is 98% homologous to the Env Gene of mouse mammary tumor virus with only one small stretch of 46 bp homologous to endogenous viral sequences. The presence and expression of this sequence is related to a group of human breast cancers in which the concept of a retroviral etiology can be entertained.

  • Detection of mammary tumor virus Env Gene-like sequences in human breast cancer.
    Cancer research, 1995
    Co-Authors: Y Wang, J F Holland, I J Bleiweiss, S Melana, X Liu, I Pelisson, A Cantarella, K Stellrecht, S Mani, B G Pogo
    Abstract:

    Mouse mammary tumor virus (MMTV) has been related to human breast cancer (BC) in previous studies. Although suggestive sequence homology to MMTV has been described in BC DNA, the presence of human endogenous retroviruses (HERs) confounded these results. We have selected a 660-bp sequence of the MMTV Env Gene with very low homology to HER or to any other human or viral Gene. We have searched for sequences homologous to it using the polymerase chain reaction. DNA was extracted from fresh or frozen tissues using primers and probes constructed to detect 660 bp; for paraffin-embedded tissues, we sought 250-bp sequences by similar methodology. The 660-bp sequence was detected in 121 (38.5%) of the 314 unselected BC samples, in cultured BC cells, in 2 (6.9%) of 29 breast fibroadenomas and in 2 (1.8%) of 107 breast specimens from reduction mammoplastias. The sequence was not found in normal tissues including breast, lymphocytes from BC patients, nor in other human cancers or cell lines. The 250-bp sequence was detected in 60 (39.7%) of the 151 BCs, and in 1 of 27 normal breast samples assayed from paraffin-embedded sections. Cloning and sequencing of the 660 bp and 250 bp demonstrated that they are 95-99% homologous to MMTV Env Gene, but not to the known HERs nor to other viral or human Genes (< 18%). Southern blot analysis using labeled cloned sequences showed that the 660-bp sequences were present in low copy number as a 7-8-kb EcoRI fragment only in breast cancer samples and two breast cancer cell lines that were positive by PCR. These data indicate that 38-40% of human breast cancers contain Gene sequences homologous to the MMTV Env Gene that are absent from other tumors and tissues. These MMTV Env Gene-like sequences may play a role in the etiology of a large proportion of human breast cancer.

Y Wang - One of the best experts on this subject based on the ideXlab platform.

  • high prevalence of mmtv like Env Gene sequences in gestational breast cancer
    Medical Oncology, 2003
    Co-Authors: Y Wang, J F Holland, S Melana, B Baker, Ira J Bleiweiss, Mariana Fernandezcobo, J F Mandeli, Bgt Pogo
    Abstract:

    Gestational breast cancer (BC) is Generally associated with rapid growth and increased mortality. Because the presence of MMTV-like sequences in BC has been associated with laminin receptor expression, a marker of poor prognosis, gestational BCs were analyzed for MMTV Env Gene-like sequences to explore whether MMTV-like sequences were also associated with its adverse outcome. Whereas 30-38% of sporadic BC have the sequences, in gestational BC the prevalence is 62%. We suggest that hormonal response elements present in the MMTV-like LTR may play a role in promoting cell growth, as they do in the mouse system.

  • MMTV-like Env Gene sequences in human breast cancer.
    Archives of virology, 2001
    Co-Authors: Y Wang, J F Holland, S Melana, I Pelisson, B G Pogo
    Abstract:

    We have previously detected an MMTV Env Gene-like 660 bp sequence in 38% of human breast cancers, but not in normal tissues or other tumors. In this communication we report the sequences from eleven tumors and three breast cancer cell lines, and compare them to four strains of MMTV and to the known endogenous retroviral sequences. The breast cancer sequences were highly homogenous to the MMTV’s, but not to the endogenous sequences suggesting an exogenous origin.

  • expression of mouse mammary tumor virus like Env Gene sequences in human breast cancer
    Clinical Cancer Research, 1998
    Co-Authors: Y Wang, J F Holland, S Melana, B G Pogo
    Abstract:

    We have reported previously (Wang et al, Cancer Res., 55: 5173-5179, 1995) the presence of a 660-bp sequence that is 90-98% homologous to the Env Gene of mouse mammary tumor virus in 38% of 314 unselected breast cancer samples, in some breast cancer cell lines, and in 1.8% of the 107 normal breast specimens from reduction mammoplasties. In this communication, we have investigated whether the 660-bp sequence or a smaller 256-bp sequence within the 660 bp were expressed in breast tumors, normal breasts, and breast cancer cell lines by means of reverse transcription-PCR. The results indicated that expression of the 660-bp sequence was detected in 66% of the sequence-positive breast tumors studied and in none of the negative tumors or normal breasts and that the 256-bp sequence was expressed in all of the Env-positive breast cancer cell lines tested. Sequence analysis revealed that the expressed 660-bp sequence is 98% homologous to the Env Gene of mouse mammary tumor virus with only one small stretch of 46 bp homologous to endogenous viral sequences. The presence and expression of this sequence is related to a group of human breast cancers in which the concept of a retroviral etiology can be entertained.

  • Detection of mammary tumor virus Env Gene-like sequences in human breast cancer.
    Cancer research, 1995
    Co-Authors: Y Wang, J F Holland, I J Bleiweiss, S Melana, X Liu, I Pelisson, A Cantarella, K Stellrecht, S Mani, B G Pogo
    Abstract:

    Mouse mammary tumor virus (MMTV) has been related to human breast cancer (BC) in previous studies. Although suggestive sequence homology to MMTV has been described in BC DNA, the presence of human endogenous retroviruses (HERs) confounded these results. We have selected a 660-bp sequence of the MMTV Env Gene with very low homology to HER or to any other human or viral Gene. We have searched for sequences homologous to it using the polymerase chain reaction. DNA was extracted from fresh or frozen tissues using primers and probes constructed to detect 660 bp; for paraffin-embedded tissues, we sought 250-bp sequences by similar methodology. The 660-bp sequence was detected in 121 (38.5%) of the 314 unselected BC samples, in cultured BC cells, in 2 (6.9%) of 29 breast fibroadenomas and in 2 (1.8%) of 107 breast specimens from reduction mammoplastias. The sequence was not found in normal tissues including breast, lymphocytes from BC patients, nor in other human cancers or cell lines. The 250-bp sequence was detected in 60 (39.7%) of the 151 BCs, and in 1 of 27 normal breast samples assayed from paraffin-embedded sections. Cloning and sequencing of the 660 bp and 250 bp demonstrated that they are 95-99% homologous to MMTV Env Gene, but not to the known HERs nor to other viral or human Genes (< 18%). Southern blot analysis using labeled cloned sequences showed that the 660-bp sequences were present in low copy number as a 7-8-kb EcoRI fragment only in breast cancer samples and two breast cancer cell lines that were positive by PCR. These data indicate that 38-40% of human breast cancers contain Gene sequences homologous to the MMTV Env Gene that are absent from other tumors and tissues. These MMTV Env Gene-like sequences may play a role in the etiology of a large proportion of human breast cancer.

S Melana - One of the best experts on this subject based on the ideXlab platform.

  • high prevalence of mmtv like Env Gene sequences in gestational breast cancer
    Medical Oncology, 2003
    Co-Authors: Y Wang, J F Holland, S Melana, B Baker, Ira J Bleiweiss, Mariana Fernandezcobo, J F Mandeli, Bgt Pogo
    Abstract:

    Gestational breast cancer (BC) is Generally associated with rapid growth and increased mortality. Because the presence of MMTV-like sequences in BC has been associated with laminin receptor expression, a marker of poor prognosis, gestational BCs were analyzed for MMTV Env Gene-like sequences to explore whether MMTV-like sequences were also associated with its adverse outcome. Whereas 30-38% of sporadic BC have the sequences, in gestational BC the prevalence is 62%. We suggest that hormonal response elements present in the MMTV-like LTR may play a role in promoting cell growth, as they do in the mouse system.

  • detection of murine mammary tumor virus mmtv Env Gene like sequences in breast cancer from argentine patients
    Medicina-buenos Aires, 2002
    Co-Authors: S Melana, J F Holland, Maria Alejandra Picconi, Carlos Rossi, Juan Mural, Lidia Virginia Alonio, Angelica Teyssie, B G Pogo
    Abstract:

    In the last years research on the possible viral etiology of human breast cancer has been revised. Previous studies have demonstrated the presence of a Mouse Mammary Tumor Virus (MMTV) Env Gene-like sequence in about 38% of breast cancers from American and Italian women; these sequences are Generally absent in other tumors and in normal mammary tissue. In the present study we have analyzed the presence of a 250-bp sequence of the MMTV Env Gene in breast cancer biopsies from Argentine patients. The retroviral fragment was present in 31% (23/74) of the tumors, only in one normal mammary tissue and in none of the fibroadenomas analYzed. Peripheral blood mononuclear cells (PBMC) from 46 cancer patients were also analyzed; the sequence was found in 17% (2/12) of the PBMC from Env positive tumor patients and in 3% (1/34) of the Env negatives. The results from Argentine samples are similar to those from USA and Italy, where the breast cancer incidence is alike. These findings support the hypothesis of a viral agent involved in the Genesis of this neoplasia and encourage the continuation of these studies.

  • MMTV-like Env Gene sequences in human breast cancer.
    Archives of virology, 2001
    Co-Authors: Y Wang, J F Holland, S Melana, I Pelisson, B G Pogo
    Abstract:

    We have previously detected an MMTV Env Gene-like 660 bp sequence in 38% of human breast cancers, but not in normal tissues or other tumors. In this communication we report the sequences from eleven tumors and three breast cancer cell lines, and compare them to four strains of MMTV and to the known endogenous retroviral sequences. The breast cancer sequences were highly homogenous to the MMTV’s, but not to the endogenous sequences suggesting an exogenous origin.

  • Sequences homologous to the mouse mammary tumor virus Env Gene in human breast carcinoma correlate with overexpression of laminin receptor.
    Clinical cancer research : an official journal of the American Association for Cancer Research, 1999
    Co-Authors: B G Pogo, J F Holland, S Melana, John F. Mandeli, Silvana Pilotti, Patrizia Casalini, Sylvie Ménard
    Abstract:

    We previously reported that a 660-bp sequence that is homologous to the Env Gene of the mouse mammary tumor virus (MMTV) but not to endogenous retroviruses or to other known Genes was present in 38% of human breast cancers and in some breast cancer cell lines studied (Y. Wang et al. , Cancer Res., 55: 5173–5179, 1995). Here, we have investigated whether the MMTV-like sequences were associated with the clinical, pathological, and molecular parameters that have been reported to define two subsets of human breast cancers. Archival breast carcinoma samples were analyzed for four clinical parameters, obtained from patients’ records, and for six pathological characteristics. Expression of c-erbB-2, p53, bcl-2, progesterone receptor, laminin receptor, and cathepsin D was detected by immunochemistry using monoclonal antibodies. PCRs were used to amplify 250 bp of the MMTV Env Gene-like sequence. The χ 2 , log-rank, and Generalized Wilcoxon tests were used to analyze the data. The MMTV Env Gene-like sequence was detected in 37.7% of the samples. The presence of this sequence was not significantly associated with any of the pathological clinical or biological parameters studied. It did correlate, however, with expression of the laminin receptor, a marker for invasiveness and poor prognosis. This is the first phenotypic characterization of human breast cancers containing retroviral sequences.

  • expression of mouse mammary tumor virus like Env Gene sequences in human breast cancer
    Clinical Cancer Research, 1998
    Co-Authors: Y Wang, J F Holland, S Melana, B G Pogo
    Abstract:

    We have reported previously (Wang et al, Cancer Res., 55: 5173-5179, 1995) the presence of a 660-bp sequence that is 90-98% homologous to the Env Gene of mouse mammary tumor virus in 38% of 314 unselected breast cancer samples, in some breast cancer cell lines, and in 1.8% of the 107 normal breast specimens from reduction mammoplasties. In this communication, we have investigated whether the 660-bp sequence or a smaller 256-bp sequence within the 660 bp were expressed in breast tumors, normal breasts, and breast cancer cell lines by means of reverse transcription-PCR. The results indicated that expression of the 660-bp sequence was detected in 66% of the sequence-positive breast tumors studied and in none of the negative tumors or normal breasts and that the 256-bp sequence was expressed in all of the Env-positive breast cancer cell lines tested. Sequence analysis revealed that the expressed 660-bp sequence is 98% homologous to the Env Gene of mouse mammary tumor virus with only one small stretch of 46 bp homologous to endogenous viral sequences. The presence and expression of this sequence is related to a group of human breast cancers in which the concept of a retroviral etiology can be entertained.

J F Holland - One of the best experts on this subject based on the ideXlab platform.

  • high prevalence of mmtv like Env Gene sequences in gestational breast cancer
    Medical Oncology, 2003
    Co-Authors: Y Wang, J F Holland, S Melana, B Baker, Ira J Bleiweiss, Mariana Fernandezcobo, J F Mandeli, Bgt Pogo
    Abstract:

    Gestational breast cancer (BC) is Generally associated with rapid growth and increased mortality. Because the presence of MMTV-like sequences in BC has been associated with laminin receptor expression, a marker of poor prognosis, gestational BCs were analyzed for MMTV Env Gene-like sequences to explore whether MMTV-like sequences were also associated with its adverse outcome. Whereas 30-38% of sporadic BC have the sequences, in gestational BC the prevalence is 62%. We suggest that hormonal response elements present in the MMTV-like LTR may play a role in promoting cell growth, as they do in the mouse system.

  • detection of murine mammary tumor virus mmtv Env Gene like sequences in breast cancer from argentine patients
    Medicina-buenos Aires, 2002
    Co-Authors: S Melana, J F Holland, Maria Alejandra Picconi, Carlos Rossi, Juan Mural, Lidia Virginia Alonio, Angelica Teyssie, B G Pogo
    Abstract:

    In the last years research on the possible viral etiology of human breast cancer has been revised. Previous studies have demonstrated the presence of a Mouse Mammary Tumor Virus (MMTV) Env Gene-like sequence in about 38% of breast cancers from American and Italian women; these sequences are Generally absent in other tumors and in normal mammary tissue. In the present study we have analyzed the presence of a 250-bp sequence of the MMTV Env Gene in breast cancer biopsies from Argentine patients. The retroviral fragment was present in 31% (23/74) of the tumors, only in one normal mammary tissue and in none of the fibroadenomas analYzed. Peripheral blood mononuclear cells (PBMC) from 46 cancer patients were also analyzed; the sequence was found in 17% (2/12) of the PBMC from Env positive tumor patients and in 3% (1/34) of the Env negatives. The results from Argentine samples are similar to those from USA and Italy, where the breast cancer incidence is alike. These findings support the hypothesis of a viral agent involved in the Genesis of this neoplasia and encourage the continuation of these studies.

  • MMTV-like Env Gene sequences in human breast cancer.
    Archives of virology, 2001
    Co-Authors: Y Wang, J F Holland, S Melana, I Pelisson, B G Pogo
    Abstract:

    We have previously detected an MMTV Env Gene-like 660 bp sequence in 38% of human breast cancers, but not in normal tissues or other tumors. In this communication we report the sequences from eleven tumors and three breast cancer cell lines, and compare them to four strains of MMTV and to the known endogenous retroviral sequences. The breast cancer sequences were highly homogenous to the MMTV’s, but not to the endogenous sequences suggesting an exogenous origin.

  • Sequences homologous to the mouse mammary tumor virus Env Gene in human breast carcinoma correlate with overexpression of laminin receptor.
    Clinical cancer research : an official journal of the American Association for Cancer Research, 1999
    Co-Authors: B G Pogo, J F Holland, S Melana, John F. Mandeli, Silvana Pilotti, Patrizia Casalini, Sylvie Ménard
    Abstract:

    We previously reported that a 660-bp sequence that is homologous to the Env Gene of the mouse mammary tumor virus (MMTV) but not to endogenous retroviruses or to other known Genes was present in 38% of human breast cancers and in some breast cancer cell lines studied (Y. Wang et al. , Cancer Res., 55: 5173–5179, 1995). Here, we have investigated whether the MMTV-like sequences were associated with the clinical, pathological, and molecular parameters that have been reported to define two subsets of human breast cancers. Archival breast carcinoma samples were analyzed for four clinical parameters, obtained from patients’ records, and for six pathological characteristics. Expression of c-erbB-2, p53, bcl-2, progesterone receptor, laminin receptor, and cathepsin D was detected by immunochemistry using monoclonal antibodies. PCRs were used to amplify 250 bp of the MMTV Env Gene-like sequence. The χ 2 , log-rank, and Generalized Wilcoxon tests were used to analyze the data. The MMTV Env Gene-like sequence was detected in 37.7% of the samples. The presence of this sequence was not significantly associated with any of the pathological clinical or biological parameters studied. It did correlate, however, with expression of the laminin receptor, a marker for invasiveness and poor prognosis. This is the first phenotypic characterization of human breast cancers containing retroviral sequences.

  • expression of mouse mammary tumor virus like Env Gene sequences in human breast cancer
    Clinical Cancer Research, 1998
    Co-Authors: Y Wang, J F Holland, S Melana, B G Pogo
    Abstract:

    We have reported previously (Wang et al, Cancer Res., 55: 5173-5179, 1995) the presence of a 660-bp sequence that is 90-98% homologous to the Env Gene of mouse mammary tumor virus in 38% of 314 unselected breast cancer samples, in some breast cancer cell lines, and in 1.8% of the 107 normal breast specimens from reduction mammoplasties. In this communication, we have investigated whether the 660-bp sequence or a smaller 256-bp sequence within the 660 bp were expressed in breast tumors, normal breasts, and breast cancer cell lines by means of reverse transcription-PCR. The results indicated that expression of the 660-bp sequence was detected in 66% of the sequence-positive breast tumors studied and in none of the negative tumors or normal breasts and that the 256-bp sequence was expressed in all of the Env-positive breast cancer cell lines tested. Sequence analysis revealed that the expressed 660-bp sequence is 98% homologous to the Env Gene of mouse mammary tumor virus with only one small stretch of 46 bp homologous to endogenous viral sequences. The presence and expression of this sequence is related to a group of human breast cancers in which the concept of a retroviral etiology can be entertained.

A. T. Panganiban - One of the best experts on this subject based on the ideXlab platform.

  • The full-length Tat protein is required for TAR-independent, posttranscriptional trans activation of human immunodeficiency virus type 1 Env Gene expression.
    Journal of virology, 1993
    Co-Authors: Yeon-soon Kim, A. T. Panganiban
    Abstract:

    Tat is a protein that dramatically increases the expression of all Genes expressed from the human immunodeficiency virus type 1 (HIV-1) long terminal repeat through interaction with a cis-acting target sequence referred to as TAR (for trans-acting responsive region). The tat Gene is divided into two coding exons which, when translated, result in the synthesis of an 86-amino-acid protein. However, the 72-amino-acid segment encoded by the first coding exon of tat is sufficient to encode a fully active Tat protein in known assays. We examined expression of the Env Gene from an LTR that lacks TAR (designated dTAR-Env). Surprisingly, only the full-length Tat peptide trans activated expression of the Env Gene from dTAR-Env. Comparison of RNA and protein expression of the Env Gene in the presence of Tat indicated that the mechanism of trans activation is posttranscriptional rather than transcriptional. To test whether the TAR-independent Tat function is specific to the HIV-1 Env Gene, we analyzed expression of heterologous Genes from the long terminal repeat lacking TAR. These heterologous Genes were not trans activated by Tat in the absence of a TAR element, which suggests that the second-exon peptide of Tat has a sequence-specific role in TAR-independent trans activation of the HIV-1 Env Gene. Analysis of a mutant in the 5' end of the Env Gene was used to identify a cis-acting sequence required for Tat responsiveness.