Is the HERV-K HML-2 Xq21.33, an endogenous retrovirus mutated by gene conversion of chromosome X in a subset of African populations, associated with human breast cancer?

The human endogenous retroviruses HERV-K HML-2 have been considered a possible cause of human breast cancer (BrC). A HERV-K HML-2 fully intact provirus Xq21.33 was recently identified in some West African people.

Structural variation of centromeric endogenous retroviruses in human populations and their impact on cutaneous T-cell lymphoma, Sézary syndrome, and HIV infection.

Background: Human Endogenous Retroviruses type K HML-2 (HK2) are integrated into 117 or more areas of human chromosomal arms while two newly discovered HK2 proviruses, K111 and K222, spread extensively in pericentromeric regions, are the first retroviruses discovered in these areas of our genome.

Methods: We use PCR and sequencing analysis to characterize pericentromeric K111 proviruses in DNA from individuals of diverse ethnicities and patients with different diseases.

Results: We found that the 5' LTR-gag region of K111 proviruses is missing in certain individuals, creating pericentromeric instability.

Characterization of human endogenous retroviral elements in the blood of HIV-1-infected individuals.

We previously reported finding the RNA of a type K human endogenous retrovirus, HERV-K (HML-2), at high titers in the plasma of HIV-1-infected and cancer patients (R. Contreras-Galindo et al., J.

Human endogenous retrovirus K (HML-2) elements in the plasma of people with lymphoma and breast cancer.

Actively replicating endogenous retroviruses entered the human genome millions of years ago and became a stable part of the inherited genetic material. They subsequently acquired multiple mutations, leading to the assumption that these viruses no longer replicate. However, certain human tumor cell lines have been shown to release endogenous retroviral particles.

Partially unspliced and fully spliced ELF3 mRNA, including a new Alu element in human breast cancer.

Using modified representational difference analysis, a DNA fragment (GC3) was isolated as a difference between a breast cancer and a normal cell line from the same patient. GC3 proved to be a fragment of intron 7 of the ELF3 gene, an ets family transcription factor, amplified in the breast cancer cell line. Using genomic walking technology, a new Alu (Alu(kwd)) was found downstream of GC3 in an antisense position between nt 8762 and nt 8763 within intron 8 of the ELF3 gene.