FIGURE 4.

Temporal association between bacterial infection and CRC progression. The development of colorectal tumors is schematically depicted from left (healthy) to right (invasive and metastasizing carcinomas). Hallmarks are a first mutation, mostly in the APC gene, resulting in immortal adenomas and a following mutation that transforms adenomas into carcinomas, often in the P53 gene. We hypothesize that adenomas and early carcinomas provide a preferred niche for S. bovis, which leads to an increased exposure to RpL7/L12 as monitored by increased serum antibodies against this bacterial antigen. By this, S. bovis and possibly related intestinal bacteria may specifically interfere with early colon carcinogenesis, whereas tumor progression may drive these bacteria out of advanced cancerous tissue (see text for details).