A human colon cancer cell line established from collagen matrix cultures transplanted into nude mice

Mitotic crossover - an evolutionary rudiment which promotes carcinogenesis of colorectal carcinoma

Mitotic crossover is a natural mechanism that is a main source of the genetic variability of primitive organisms. In complex organisms such as mammals, it represents an evolutionary rudiment which persisted as one of the numerous DNA repair mechanisms, and results in the production of homozygous allele combinations in all heterozygous genes located on the chromosome arm distal to the crossover. This event is familiar as loss of heterozygosity, which is one of the key mechanisms responsible for the development and progression of almost all cancers. We propose the hypothesis in which mitotic crossover is a principal source of the increased loss of heterozygosity that leads to the initiation and progression of colorectal carcinoma. The hypothesis could be tested by in vitro inhibition of Rad51 protein, orthotopic grafting of human colon cancer tissue into the gut of mice, and treatment with potential inhibitors. After these procedures, the frequency of mitotic crossover would be estimated. The development of selective inhibitors of mitotic crossover could stop further carcinogenesis of colorectal carcinoma, as well as many other neoplastic events. Loss of heterozygosity is an event responsible for carcinogenesis, its reduction by selective inhibitors of mitotic crossover could have a positive effect on cancer chemoprevention, as well as on growth reduction and a cessation in the progression of earlier developed tumors.

Multiplicity of fibronectin-binding alpha V integrin receptors in colorectal cancer

Current data from in vitro and in vivo animal models indicate that fibronectin-binding integrin receptors expressed by colon cancer cells may regulate tumour growth. While individual members of the beta 1 subfamily of integrins have now been clearly identified in colorectal cancer, little information exists with respect to the alpha V subfamily. In the present study we show that alpha V can associate with multiple and different beta subunits capable of binding fibronectin in this tumour type. This is likely to have functional implications for growth and spread of colorectal cancer.