ABSTRACT
Cancers are characterized by unrestricted cell division and independency of growth factor and other external signal responsiveness. Eukaryotic parental cells of tumors, on the other hand, constitute tissues and other higher structures like organs and systems and are capable of performing various functions in a highly co-ordinated fashion. Hence, cancer cells may be considered as entities capable of incessant growth and cell division but lacking any evolutionarily advanced intracellular or intercellular regulation. Since receptor tyrosine kinases are highly altered and exist in deregulated/constitutively active forms in cancer cells - achieved through various epigenetic mechanisms - we hypothesize the functional RTKs in cancer cells to resemble their counterparts in more primitive species. Analysis of RTK sequences of various species and of cancer is, therefore, expected to prove this hypothesis. Association rule in data mining can reveal the hidden biological information. This study utilizes the Boolean association rule to mine the occurrence pattern of glycine, arginine and alanine in receptor tyrosine kinases (RTKs) of invertebrates, vertebrates and cancer related vertebrate RTKs based on protein sequence informations. The results reveal that vertebrate cancer RTKs resembles prokaryotes and invertebrate RTKs showing an increasing trend of glycine, alanine and decreasing trend in arginine composition. The aminoacid compositions of vertebrates: invertebrates: prokaryotes: vertebrate cancer with respect to Glycine (>=6.1) were 42.86: 50.0: 85.71: 100%, Alanine (>=6.2) were 10.72: 66.67: 85.71: 100%, whereas Arginine (>=5.9) were 21.43: 16.67: 14.29: 0%, respectively. In conclusion, results from this study supports our hypothesis that cancer cells may resemble lower organisms since functionally cancer cells are unresponsive to external signals and various regulatory mechanisms typically found in higher eukaryotes are largely absent.
