Expression levels of the focal adhesion-associated proteins paxillin and p130CAS in canine and feline mammary tumors

International audiencePaxillin and p130$^{{\rm CAS}}$ are two adaptor proteins localized at the focal adhesions which play an important role in cell signaling, cell motility and oncogenic transformation. In this study we evaluated the levels of paxillin and p130$^{{\rm CAS}}$ in feline and canine mammary tumor tissues at different stages of malignancy. The results obtained by Western blotting analysis showed no significant differences in the amounts of paxillin and p130$^{{\rm CAS}}$ between normal and non-invasive tumor tissues. By contrast, mammary tumor tissues with the invasive phenotype showed lower levels of paxillin $P < 0.01$ and higher levels of p130$^{{\rm CAS}}$ $P < 0.001$ than normal tissues. The decrease $P < 0.001$ of the amount of paxillin and the increase $P < 0.001$ of p130$^{{\rm CAS}}$ levels were correlated with the progression stage of malignancy. Since paxillin and p130$^{{\rm CAS}}$ are involved in regulating cell migration, our results suggest that low levels of paxillin together with high levels of p130$^{{\rm CAS}}$ expression may cause certain breast cancers to be more motile and possibly more aggressive. Thus, both paxillin and p130$^{{\rm CAS}}$ may represent useful prognosticators of feline and canine breast cancer malignancy

Expression levels of the focal adhesion-associated proteins paxillin and p130CAS^{{\rm CAS}} in canine and feline mammary tumors

Paxillin and p130$^{{\rm CAS}}$ are two adaptor proteins localized at the focal adhesions which play an important role in cell signaling, cell motility and oncogenic transformation. In this study we evaluated the levels of paxillin and p130$^{{\rm CAS}}$ in feline and canine mammary tumor tissues at different stages of malignancy. The results obtained by Western blotting analysis showed no significant differences in the amounts of paxillin and p130$^{{\rm CAS}}$ between normal and non-invasive tumor tissues. By contrast, mammary tumor tissues with the invasive phenotype showed lower levels of paxillin $P < 0.01$ and higher levels of p130$^{{\rm CAS}}$ $P < 0.001$ than normal tissues. The decrease $P < 0.001$ of the amount of paxillin and the increase $P < 0.001$ of p130$^{{\rm CAS}}$ levels were correlated with the progression stage of malignancy. Since paxillin and p130$^{{\rm CAS}}$ are involved in regulating cell migration, our results suggest that low levels of paxillin together with high levels of p130$^{{\rm CAS}}$ expression may cause certain breast cancers to be more motile and possibly more aggressive. Thus, both paxillin and p130$^{{\rm CAS}}$ may represent useful prognosticators of feline and canine breast cancer malignancy