α- and β-tubulin Expression in Rectal Cancer Development

Background: Microtubules are involved in cell growth and division, motility, signalling and in the development and maintenance of cell shape. Consequently, the non-equilibrium dynamics of these microtubules can be crucial to cellular function, including cancer development. Although the involvement of tubulins in human development has been well investigated, the role of ·- and ‚-tubulins in human tumorigenesis still remains controversial. The aim of this study was to investigate ·- and ‚-tubulin protein expression in rectal cancer development. Patients and Methods: By immuno- histochemistry, using ·- and ‚-tubulin monoclonal antibodies, 66 patients were examined, 32 of whom (22 male, 10 female; range 31-60 years, mean age 49.5 years) had preneoplastic lesions discovered during endoscopic surveillance, which were classified as mild, moderate and severe dysplastic polyps of the rectum, and 34 had invasive adenocarcinomas (24 male, 10 female; range 39-60 years, mean 52 years) of the rectum, with no local or distant metastases at the time of surgical resection. Results: In preneoplastic lesions, no statistically significant relationship was found among ·- and ‚-tubulin protein expression, grade of dysplasia, or other clinical data. Statistical association among ·- and ‚-tubulin immunoreactivity and Dukes' stages B and C was found with p=0.017 and p=0.009, respectively. No statistical relationship was found between ·- and ‚-tubulin protein expression among different grades of dysplasia. On the contrary, a significant relationship was detected among tubulins in different stages of cancer. Conclusion: In this preliminary study a significant difference of ·- and ‚-tubulin protein expressions was found in polyps and invasive cancer of the rectum, indicating a possible role of tubulins in invasive, but not in preinvasive cancer development. This preliminary data suggest the possibility of performing ·- and ‚-tubulin protein expression in order to identify B stage versus C stage rectal cancer, before surgical treatment. Disorganization and pleomorphism, including structural changes in cell, nuclear, nucleolar and chromatin pattern, represent marks of cancer diagnosis and therapy decision. Dynamic structures of normal cells that involve equilibrium of the polymerization and depolymerization of many structural proteins are actins, intermediate keratins, tubulins and nuclear components such as lamins, collagens and cellular matrix. Microtubules and actin filaments are