BACKGROUND: S100 A2 and hnRNP A2/B1 (heterogeneous ribonucleoprotein A2/B1) with its splicing variant hnRNP B1 are proteins which are involved in cellular proliferation, differentiation and protein synthesis and are up-regulated in non-small cell lung cancer (NSCLC). Since previous studies using paraffin-embedded tissues indicated a high potential of these markers for diagnosis and screening the present analysis intended to validate these data applying cryostat sections. METHODS: 78 tumor-infiltrated lung cancer specimens and 66 adjacent histologically tumor-free tissues were analyzed; 11 autopsy specimens from patients who did not suffer from a malignant disease served as a control group. Cryostat sections were stained with monoclonal antibodies against hnRNP A2/B1, hnRNP B1 and S100 A2 and were compared with the previously established immunohistochemical profile of the same patients including EGFR, EGFRvIII, pEGFR, c-erbB-2, c-erbB-3, p53, Ki-67, bcl-2, p120 and microvessel density. Furthermore, these results were correlated with clinical parameters. RESULTS: Expression of hnRNP A2/B1, hnRNP B1 and S100 A2 was increased in the tumor group when compared with the microscopic tumor-free specimens in 10% versus 5% (n.s.), 91% versus 5% and 65% versus 6%, respectively. Increased S100 and A2 hnRNP A2/B1 expressions were negative prognostic factors. With the exception of an increased EGFR expression in hnRNP A2/B1 negative cases the three analyzed markers did not correlate with the immunohistochemical parameters tested previously. CONCLUSION: Comparison between tumor probes and tumor-free specimens of NSCLC patients failed to approve the diagnostic relevance of hnRNP A2/B1 shown in previous studies, whereas hnRNP B1 revealed a high tumor specificity that could be helpful for tumor cell screening. Moreover, S100 A2 and hnRNP A2/B1 confirmed to be valuable prognostic parameters.
BACKGROUND:S100 A2 and hnRNP A2/B1 (heterogeneous ribonucleoprotein A2/B1) with its splicing variant hnRNP B1 are proteins which are involved in cellular proliferation, differentiation and protein synthesis and are up-regulated in non-small cell lung cancer (NSCLC). Since previous studies using paraffin-embedded tissues indicated a high potential of these markers for diagnosis and screening the present analysis intended to validate these data applying cryostat sections. METHODS: 78 tumor-infiltrated lung cancer specimens and 66 adjacent histologically tumor-free tissues were analyzed; 11 autopsy specimens from patients who did not suffer from a malignant disease served as a control group. Cryostat sections were stained with monoclonal antibodies against hnRNP A2/B1, hnRNP B1 and S100 A2 and were compared with the previously established immunohistochemical profile of the same patients including EGFR, EGFRvIII, pEGFR, c-erbB-2, c-erbB-3, p53, Ki-67, bcl-2, p120 and microvessel density. Furthermore, these results were correlated with clinical parameters. RESULTS: Expression of hnRNP A2/B1, hnRNP B1 and S100 A2 was increased in the tumor group when compared with the microscopic tumor-free specimens in 10% versus 5% (n.s.), 91% versus 5% and 65% versus 6%, respectively. Increased S100 and A2 hnRNP A2/B1 expressions were negative prognostic factors. With the exception of an increased EGFR expression in hnRNP A2/B1 negative cases the three analyzed markers did not correlate with the immunohistochemical parameters tested previously. CONCLUSION: Comparison between tumor probes and tumor-free specimens of NSCLCpatients failed to approve the diagnostic relevance of hnRNP A2/B1 shown in previous studies, whereas hnRNP B1 revealed a high tumor specificity that could be helpful for tumor cell screening. Moreover, S100 A2 and hnRNP A2/B1 confirmed to be valuable prognostic parameters.