Suspicions that the sexually transmitted disease chlamydia increases the risk of abdominal cancer have been heightened by the discovery that an untreated infection can knock out the body’s first line of defence. Pictured is a human cell that has been freeze-fractured in the laboratory to reveal a colony of chlamydia bacteria, false coloured green, inside. This type of infection can damage DNA and when this happens, the cell’s response is to produce a protein called p53. This tumour-suppressing agent either repairs the DNA or, if the damage is too severe, triggers apoptosis – self-destruction of the cell to avoid it becoming malignant. Scientists discovered that chlamydia bacteria can destroy the p53 protein, leaving the cell with dangerously low levels. This ensures their survival by preventing the cell’s suicide, which would also destroy the colony.
Written by Mick Warwicker
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