Vaginal lubricants can reduce cervical cancer risk

Boffins have found that spermicides and vaginal lubricants control the growth of infection caused by human papillomavirus (HPV), which causes cervical cancer.

London, July 2 : Boffins have found that spermicides and vaginal lubricants control the growth of infection caused by human papillomavirus (HPV), which causes cervical cancer.

The study was conducted by a team of researchers led by John Schiller at the National Cancer Institute, Bethesda, Maryland.

The problem with doing the experiments was that HPV survive only in humans, making it difficult to form a mouse model, and also the virus does not replicate properly in cell cultures.

However, in the first stages of infection, when the virus enters the cell, it is not species specific.

As part of the study, researchers experimented on mice with early stages of HPV infection by forming an HPV 'pseudovirus' which had the same protein coat as HPV but a different genome, and could replicate in cell cultures.

The pseudovirus was also marked with a fluorescent tag, which enabled scientists to follow the growth of infection.

"The pseudovirus mimics the initial phases of infection well. No model is perfect, but we feel that ours is by far the best," Nature quoted Schiller, as saying.

Researchers then treated the model with spermicide nonoxynol-9 and vaginal lubricants.

The study found that nonoxynol-9 increased the risk of HPV infection in mouse, while vaginal lubricant carrageenan hindered the virus by stopping the infection.

Nonoxynol-9 is believed to worsen the cells in the lining of the vaginal tract that might allows the virus to cause infection by reaching the underlying membrane.

According to Lesley Walker, of Cancer Research UK in Hull, the study could help treat cervical cancer.

"It could be key in understanding the early events in the development of cervical cancer," Walker said.

The study noted that intact cells in the genital tract lining were HPV resistant and would not bind to the virus.

"The crucial step for infection seems to be the virus binding to the basement membrane that underlies these cells," Schiller said.

ANI