Metastatic colorectal cancer stimulates collagen synthesis by fibroblasts

We ascertained in vitro whether there were any differences in the growth of fibroblasts and the production of collagen (PIIIP), in relation to the presence of conditioning sera or tumor tissues from colorectal cancer (CRC) patients with disease progression or regression after surgery.

Fibroblasts were conditioned with: 1) 10% of control (n=20) or CRC patients' (n=57) sera; 2) 10% of tumor tissue homogenates obtained from CRC patients without (group A, n=6) or with (group B, n=5) liver metastases. After surgery, 29/57 patients (group 1) developed while 28/57 (group 2) did not develop a recurrent disease.

The ratio between cell growth and PIIIP production increases when fibroblasts were conditioned by group I (p<0.05), but not by controls or group 2 sera. Tumor homogenates from group B inhibited cell growth (p<0.001), while they induced PIIIP production (p<0.001) in comparison with results from group A.

CRC non-metastatic cancer cells induce mainly fibroblasts growth, while metastatic cells mainly induce collagen synthesis. This effect is probably caused by soluble mediators, which partly pass into the systemic circulation.