Figure 5

A parsimonious model of 8p rearrangements. The different patterns of 8p rearrangement that would be expected in a sample of tumours based on the number and position of tumour suppressor genes (not to scale). Top is the pattern of rearrangements expected if there is a single tumour suppressor gene located in 8p12. Middle is the pattern of rearrangements predicted if there were at least two tumour suppressor genes located on 8p, one in 8p12 and one located close to the telomere in 8p23.3. This fits the common overall pattern of breaks in 8p12 with loss of distal 8p. Bottom is a representation of some of the atypical 8p rearrangements found in cancer cell lines including DU4475, HCC1500 and PMC42. These can be explained by the presence of other tumour suppressor genes in between those in 8p12 and 8p23.3; our results suggest at least one, at 8p22. Since each of these tumour suppressor genes is only lost in a proportion of cases a complex pattern of rearrangements encompassing some or all of these regions results. Loss of the whole of distal 8p will be the most common rearrangement as it removes all tumour suppressor genes as the result of a single event.