Ephrin (Eph) receptor A1, A4, A5 and A7 expression in human non-small cell lung carcinoma: associations with clinicopathological parameters, tumor proliferative capacity and patients’ survival

Abstract

BackgroundEphrin (Eph) receptors are frequently overexpressed in a wide variety of human malignant tumors, being associated with tumor growth, invasion, metastasis and angiogenesis. The present study aimed to evaluate the clinical significance of EphA1, A4, A5 and A7 protein expression in non-small cell lung carcinoma (NSCLC).MethodsEphA1, A4, A5 and A7 protein expression was assessed immunohistochemically in tissue microarrays of 88 surgically resected NSCLC and was analyzed in relation with clinicopathological characteristics and patients’ survival.ResultsElevated EphA4 expression was significantly associated with low histopathological stage and presence of inflammation (p = 0.047 and p = 0.026, respectively). Elevated EphA7 expression was significantly associated with older patients’ age, presence of fibrosis and smaller tumor size (p = 0.036, p = 0.029 and p = 0.018, respectively). EphA1, A5 and A7 expression were positively associated with tumor proliferative capacity (p = 0.047, p = 0.002 and p = 0.046, respectively). Elevated EphA4, A5 and A7 expression were identified as predictors of favourable patients’ survival at both univariate (Log-rank test, 0 = 0.019, p = 0.006 and p = 0.012, respectively) and multivariate levels (Cox-regression analysis, p = 0.029, p = 0.068 and p = 0.044, respectively).ConclusionsThe present study supported evidence that Ephs may be involved in lung cancer progression, reinforcing their utility as clinical biomarkers for patients’ management and prognosis, as also as potential targets for future therapeutic interventions.

Clinical Significance of EphB4 and EphB6 Expression in Human Malignant and Benign Thyroid Lesions

“…Finally, the expression of EphB4 and EphB6 was classified as low; if the total score was 0 or 2 and high; if the total score was ≥3. In this way, we ensure that each group has a sufficient and more homogeneous number of cases in order to be comparable with the other groups [17][18][19][20]. Ki-67 immunoreactivity was classified according to the percentage of positively stained follicular cells exceeded the median percentage value into two categories (below and over mean value), as previously reported [17][18][19][20].…”

“…Specimens were considered "positive" for EphB4 and EphB6 when more than 5 % of tumour cells within the section were positively stained [17][18][19][20]. The immunoreactivity of the tumor cells for EphB4 and EphB6 was scored according to the percentage of EphB4 and EphB6 positive tumor cells as 0: negative staining-0-4 % of tumor cells positive; 1: 5-24 % of tumor cells positive; 2: 25-49 % of tumor cells positive; 3: 50-100 % of tumor cells positive, and its intensity as 0: negative staining, 1: mild staining; 2: intermediate staining; 3: intense staining [17][18][19][20]. Finally, the expression of EphB4 and EphB6 was classified as low; if the total score was 0 or 2 and high; if the total score was ≥3.…”

“…Appropriate negative controls were performed by omitting the primary antibody and/or substituting it with an irrelevant anti-serum. The follicular cells' proliferative capacity was assessed by Ki-67 immunohistochemical expression, as previously described [17][18][19][20].…”

“…Immunostainings for EphB4 and EphB6 were performed on formalin-fixed, paraffin-embedded tissue sections using commercially available rabbit polyclonal EphB4 (H-200, sc-5536) and EphB6 (H-90, sc-25461) primary IgG antibodies (Santa Cruz Biochemicals, Santa Cruz, CA, USA) for 1 h, at a dilution 1:150 and 1:200, respectively, as previously described [17][18][19][20]. As positive control, breast cancer tissue sections with known increased EphB4 and EphB6 positivity were used.…”

“…The most comprehensive data so far is mainly restricted to EphA subfamily [6,7,[17][18][19][20]. In the last few years, the clinical significance of EphB subfamily members has also been assessed in several human malignancies [21][22][23][24][25][26].…”