Objective To explore the effect of membrane surface nucleolin （NCL） on activation of epidermal growth factor receptor （EGFR） signaling. Methods Immunohistochemistry was used to identify the expressions of membrane surface NCL or EGFR in pallilary thyroid carcinoma （PTC） tissues. The level of phosphorlated EGFR in TPC-1 cells was observed by Western blot. TPC-1 cells invasion capacity was detected by Transwell assay. Results The posi-tive expression rates of membrane surface NCL and EGFR in PTC tissues were 100% （56/56） and 80.4% （45/56） respe-ctively， while the expressions of NCL and EGFR were related with lymph node metastasis （P＜0.05）. There was posi-tive correlation between the expressions of NCL and EGFR （r=0.635， P＜0.01）. Western blot showed that anti-NCL or anti-EGFR of TPC-1 cells could inhibit the expression of phosphorlation EGFR （P＜0.01）. Transwell assay showed the number of membrane-invading cells were reduced significantly in anti-NCL group anti-EGFR group （P＜0.01）. Conclusions Membrane surface NCL may be a kind of indispensable component in activation of EGFR signaling， by which EGFR can participate in growth and invasion of tumors. NCL can be used as a target for developing a new field of tumor treatment.
ObjectiveTo investigate the expressions of Snail and N-cadherin protein in thyroid papillary carcinoma (PTC) tissues and cell lines, and then discuss the clinical value of Snail and N-cadherin expressions. MethodsImmunohis-tochemical SP technique was performed to detect the expressions of Snail and N-cadherin protein in 60 cases of PTC, and the relation between the expression of Snail or N-cadherin and clinicopathologic indicators was analyzed. Western blot was used to investigate the constitutive and inducible expressions of Snail and N-cadherin protein. Results①The positive rates of Snail and N-cadherin protein expressions were 85.0% (51/60) and 78.3% (47/60) respectively in the PTC tissues of 60 patients with PTC, which were significantly higher than those (0, 0, respectively) in the corresponding normal tissues adjacent to the cancer (P < 0.01).②The positive rates of Snail and N-cadherin protein expressions in the PTC with lymph node metastasis were significantly higher than those in the PTC without lymph node metastasis (P < 0.01), which were not related with the gender, age, tumor size of the patients (P > 0.01).③There was a positive correlation between Snail and N-cadherin protein positive expression (rs=0.721, P < 0.001).④The constitutive and inducible expressions of Snail and N-cadherin in the PTC tissues and cell lines further were identified by Western blot. ConclusionsSnail and N-cadherin could constitutively express in PTC, which might play important roles in the development and metastasis of PTC. Snail and N-cadherin might be used as effective indicators.