engleski

Expression of the epidermal growth factor (EGF) receptor family of receptor tyrosine kinases in sporadic cardiac myxoma cases

AIMS: The epidermal growth factor receptor family (EGFR) consisting of four tyrosine kinas receptors, EGFR1/c-erbB1, c-erbB2, cerbB3 and cerbB4. They are involved in tumor cell proliferation, differentiation, survival and angiogenesis. Co-expressed in the same neoplastic cell source with accompanying hetero-dimerization they further enhance pathologically important signaling transduction pathways. In the presented study, we analyzed the expression and cellular distribution of EGFR family members in sporadic cardiac myxoma lesions of human heart. METHODS AND RESULTS: The study included 36 patients, who were treated with surgical excision of the lesion. Expression of EGFR1/c-erbB1, c-erbB2, cerbB3 and cerbB4 was studied by immunohistochemical staining and QRT-PCR. The patient population was comprised of 27 (75%) women and 9 (25%) men. The mean age of the patients were 63 years, with an age range of 34 to 87 years. All study cases were sporadic myxomas. All lesions were located in the left atrium. Majority of examined cardiac myxoma cases demonstrate moderateto- strong and overlapping expression of EGFR family protein members in all commonly present histological types of neoplastic myxoma cells except the c-erbb2 which was immunohistochemically negative in all cases. c-erbB4 showed the highest and statistically significant decrease in expression on mRNA level compared to normal left atrial tissue. Compared relative quantities of EGFR protein members with each other that c-erbB3 and crbB2 are the only ones exhibiting statistically significant (r=0.721, p=0.01304), and positive correlation. CONCLUSION: EGFR1/c-erbB1, cerbB3 and cerbB4 are co-expressed in cardiac myxoma lesions and may play a distinct role in their pathogenesis.

Cardiac myxoma; EGFR1/c-erbB1; c-erbB2; cerbB3; cerbB4: co-expression; left

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