title: Prevalence of HMTV in breast carcinomas and unaffected tissue from Mexican women.
abstract: BACKGROUND
  Breast cancer is a complex multifactorial genetic disease. Among other factors, race and, to an even greater extent, viruses are known to influence the development of this heterogeneous disease. It has been reported that MMTV-like (HMTV) gene sequences with a 90 to 98% homology to mouse mammary tumor virus are found in several populations with a prevalence range of 0 to 74%. In the Mexican population, 4.2% of patients with breast cancer exhibit the presence of HMTV (MMTV-like) sequences. The aim of this study was to evaluate the presence and current prevalence of retroviral HMTV (MMTV-like) sequences in breast cancer in Mexican women.
  
  
  METHODS
  We used nested PCR and real-time PCR with a TaqMan probe. As a positive control, we used the C3H MMTV strain inserted into pBR322 plasmid. To confirm that we had identified the HMTV sequences, we sequenced the amplicons and compared these sequences with those of MMTV and HMTV (GenBank AF033807 and AF346816).
  
  
  RESULTS
  A total of 12.4% of breast tumors were HMTV-positive, and 15.7% of the unaffected tissue samples from 458 patients were HMTV-positive. A total of 8.3% of the patients had both HMTV-positive tumor and adjacent tissues. The HMTV-positive samples presented 98% similarity to the reported HMTV sequence.
  
  
  CONCLUSIONS
  These results confirm that the HMTV sequence is present in breast tumors and non-affected tissues in the Mexican population. HMTV should be considered a prominent causative agent of breast cancer.
authors.forename: Alberto
authors.initials: A
authors.lastname: Cedro-Tanda
authors.forename: Alejandro
authors.initials: A
authors.lastname: Córdova-Solis
authors.forename: Teresa
authors.initials: T
authors.lastname: Juárez-Cedillo
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Pina-Jiménez
authors.forename: Marta E
authors.initials: ME
authors.lastname: Hernández-Caballero
authors.forename: Christian
authors.initials: C
authors.lastname: Moctezuma-Meza
authors.forename: Germán
authors.initials: G
authors.lastname: Castelazo-Rico
authors.forename: Alejandro
authors.initials: A
authors.lastname: Gómez-Delgado
authors.forename: Alejandro Cruz
authors.initials: AC
authors.lastname: Monsalvo-Reyes
authors.forename: Fabio A
authors.initials: FA
authors.lastname: Salamanca-Gómez
authors.forename: Diego J
authors.initials: DJ
authors.lastname: Arenas-Aranda
authors.affiliation: Medical Research Unit in Human Genetics, Pediatric Hospital, CMN S-XXI, IMSS, Mexico City, Mexico. normandgarcia@gmail.com.
authors.forename: Normand
authors.initials: N
authors.lastname: García-Hernández
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology* / Q000473:pathology; D003430:Cross-Sectional Studies; D004279:DNA, Viral; D005260:Female; D015686:Gene Products, env / Q000235:genetics; D006801:Humans; D042361:Mammary Glands, Human / Q000821:virology; D008324:Mammary Tumor Virus, Mouse / Q000145:classification / Q000235:genetics; D008800:Mexico / Q000453:epidemiology; D051379:Mice; D008875:Middle Aged; D010802:Phylogeny; D015995:Prevalence; D011446:Prospective Studies; D012192:Retroviridae Infections / Q000150:complications* / Q000821:virology; D014412:Tumor Virus Infections / Q000150:complications* / Q000821:virology
chemical_list: D004279:DNA, Viral; D015686:Gene Products, env