Aberrant cell fusion may initiate cancerous processes and tumour formation, shows a new study.
 
 The results explain how fusion of one normal cell with another triggers a "genomic catastrophe" that converts normal cells to cancer cells and enables tumours to form.
 
 The study provides the missing link between single cell fusion and multiple catastrophic genetic changes that transform normal cells into cancerous cells.
 
 "We believe one cell fusion event can both initiate malignancy and fuel evolution of the tumour that ensues," said lead author Xiaofeng Zhou from the University of Michigan's department of internal medicine.
 
 Researchers studied rat IEC-6 intestinal epithelial cells because such cells maintain a stable diploid genomic structure — two sets of chromosomes lack the cellular characteristics of cancer cells and replicate normally.
 
 When fused IEC-6 cells were transplanted into immunodeficient mice, aberrant cells formed tumours.
 
 Over the course of 12 weeks, these cells generated tumours in 61 percent (11/18) of the hosts whereas no tumours formed from the parental IEC-6 cells or IEC-6 cells that did not fuse.
 
 Cell fusion has been postulated as a possible cause for some cancers because it could explain the occurrence of multiple genetic changes thought to underlie cancer.
 
 The accumulation of spontaneous genetic changes, or mutations, that occur when cells divide can be quickened by exposure to carcinogens such as cigarette smoke in the case of lung cancer and infectious agents such as the papillomavirus cervical cancer.
 
 The study appeared in the American Journal of Pathology.