RESUMEN
BACKGROUND: In Mexico City, the incidence of childhood acute lymphoblastic leukemia (ALL) is one of the highest in the world; epidemiologic evidence suggests that infectious agents could be involved in the genesis of this disease. Early transmitted oncogenic retroviruses infecting lymphocytes are important candidates. METHODS: PCR-based assays were used to screen viral genomic sequences of human T-cell lymphotrophic virus, type 1 (HTLV1) and mouse mammary tumor virus (MMTV)-like virus (MMTV-LV) in leukemic cells from 67 pediatric patients with ALL. RESULTS: Viral genomic sequences were not detected in any sample by neither standard nor nested PCR. CONCLUSIONS: Because of the methodologic strictness and high statistical power of the study, these results suggest that HTLV1 and MMTV-LV are not involved in the genesis of childhood ALL in Mexican children. IMPACT: To our knowledge, this is the first work exploring the direct participation of HTLV1 and MMTV-LV retroviruses in childhood ALL development.
Asunto(s)
Virus Linfotrópico T Tipo 1 Humano/aislamiento & purificación , Virus del Tumor Mamario del Ratón/aislamiento & purificación , Leucemia-Linfoma Linfoblástico de Células Precursoras/virología , Adolescente , Niño , Preescolar , Femenino , Virus Linfotrópico T Tipo 1 Humano/genética , Humanos , Incidencia , Lactante , Masculino , Virus del Tumor Mamario del Ratón/genética , Reacción en Cadena de la PolimerasaRESUMEN
BACKGROUND: Previous studies have reported on the presence of Murine Mammary Tumor Virus (MMTV)-like gene sequences in human cancer tissue specimens. Here, we search for MMTV-like gene sequences in lung diseases including carcinomas specimens from a Mexican population. This study was based on our previous study reporting that the INER51 lung cancer cell line, from a pleural effusion of a Mexican patient, contains MMTV-like env gene sequences. RESULTS: The MMTV-like env gene sequences have been detected in three out of 18 specimens studied, by PCR using a specific set of MMTV-like primers. The three identified MMTV-like gene sequences, which were assigned as INER6, HZ101, and HZ14, were 99%, 98%, and 97% homologous, respectively, as compared to GenBank sequence accession number AY161347. The INER6 and HZ-101 samples were isolated from lung cancer specimens, and the HZ-14 was isolated from an acute inflammatory lung infiltrate sample. Two of the env sequences exhibited disruption of the reading frame due to mutations. CONCLUSION: In summary, we identified the presence of MMTV-like gene sequences in 2 out of 11 (18%) of the lung carcinomas and 1 out of 7 (14%) of acute inflamatory lung infiltrate specimens studied of a Mexican Population.
Asunto(s)
Neoplasias de la Mama/virología , Carcinoma/virología , Genes env , Virus del Tumor Mamario del Ratón/genética , Neumonía/virología , Infecciones por Retroviridae/virología , Infecciones Tumorales por Virus/virología , Animales , Secuencia de Bases , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Carcinoma/epidemiología , Carcinoma/genética , Carcinoma/patología , Cartilla de ADN , ADN Viral/genética , Bases de Datos Genéticas , Femenino , Pruebas Genéticas , Humanos , Virus del Tumor Mamario del Ratón/aislamiento & purificación , México/epidemiología , Ratones , Datos de Secuencia Molecular , Mutación , Derrame Pleural Maligno/química , Neumonía/epidemiología , Neumonía/genética , Neumonía/patología , Reacción en Cadena de la Polimerasa , Infecciones por Retroviridae/epidemiología , Infecciones por Retroviridae/genética , Infecciones por Retroviridae/patología , Análisis de Secuencia de ADN , Homología de Secuencia de Ácido Nucleico , Infecciones Tumorales por Virus/epidemiología , Infecciones Tumorales por Virus/genética , Infecciones Tumorales por Virus/patologíaRESUMEN
It is well known that the etiology of human breast cancer is significantly affected by environmental factors. Virus-associated cancer refers to a cancer where viral infection results in the malignant transformation of the host's infected cells. Human papillomaviruses (HPV), mouse mammary tumor virus (MMTV) and Epstein-Barr (EBV) virus are prime candidate viruses as agents of human breast cancer. The precise role that viruses play in tumorigenesis is not clear, but it seems that they are responsible for causing only one in a series of steps required for cancer development. The idea that a virus could cause breast cancer has been investigated for quite some time, even though breast cancer could be a hereditary disease; however, hereditary breast cancer is estimated to account for a small percentage of all breast cancer cases. Based on current research, this review present at moment, substantial, but not conclusive, evidence that HPV, EBV and MMTV may be involved in breast cancer.
Asunto(s)
Neoplasias de la Mama/virología , Animales , Neoplasias de la Mama/etiología , Neoplasias de la Mama/patología , Femenino , Herpesvirus Humano 4/aislamiento & purificación , Herpesvirus Humano 4/patogenicidad , Humanos , Neoplasias Mamarias Animales/virología , Virus del Tumor Mamario del Ratón/aislamiento & purificación , Virus del Tumor Mamario del Ratón/patogenicidad , Ratones , Papillomaviridae/aislamiento & purificación , Papillomaviridae/patogenicidadRESUMEN
BACKGROUND: Previous reports related the presence of mouse mammary tumor virus (MMTV)-like gene sequences to human breast carcinoma. The aim of this study was to determine whether MMTV-like env gene sequences are present in breast cancer samples of Mexican women and in breast and lung cancer cell lines. METHODS: Using specific primers for MMTV, we tested 3 breast cancer cell lines, 4 non-small lung cancer cell lines and 119 breast cancer samples from Mexican women. RESULTS: MMTV-like gene sequences were amplified in the lung cancer cell INER-51, but not in the MCF-7 cell line that has been used as a positive control in other reports and in 5 of 119 (4.2%) breast cancer biopsy tissues. Furthermore, the identity of sequences of PCR products from INER-51 and a breast cancer-positive sample are 98 and 99% when compared with the env region of MMTV (GenBank accession No. AY161347). CONCLUSION: These results indicate that MMTV-like gene sequences are present in the Mexican population.
Asunto(s)
Neoplasias de la Mama/virología , Genes env , Virus del Tumor Mamario del Ratón/genética , Virus del Tumor Mamario del Ratón/aislamiento & purificación , Neoplasias de la Mama/patología , Línea Celular , Cartilla de ADN , ADN de Neoplasias/análisis , Femenino , Humanos , México , Datos de Secuencia MolecularRESUMEN
A convenient method for purifying RNA tumor viruses is described. Viruses banded in isopycnic gradients are contaminated with membranes that can be removed by velocity sedimentation in glycerol gradients. On sodium dodecyl sulfate (SDS) gel electrophoresis, the particles purified by these procedures from mouse mammary tumor tissue show protein profiles typical of those observed with virus purified from milk.