Effect of gefitinib on the migration of triple-negative breast cancer cell line MDA-MB-231 cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the effect of gefitinib on the migration of triple-negative breast cancer cell line MDA-MB-231 cells.</p><p><b>METHODS</b>Gefitinib was used in concentrations of 0 micromol/L, 0.1 micromol/L, 1 micromol/L, 10 micromol/L and 20 micromol/L, respectively. Phosphorylation levels of EGFR and Akt were analyzed by Western blot. The capability of migration was measured by scratch test and Boyden chamber assay. Microfilaments (cell skeleton ) remolding and polarization were evaluated by immunofluorescence microscopy.</p><p><b>RESULTS</b>Comparing with the control group (0 micromol/L gefitinib), gefitinib effectively inhibited the phosphorylation of EGFR and its downstream key proteins, and the effect displayed an obvious dose-effect relationship. At 24 hours after wound scratch, the cell migration distance of each group with 0, 0.1, 1, 10, 20 micromol/L gefitinib was (36.3 +/- 4.0) microm, (30.3 +/- 3.8) microm, (26.8 +/- 3.3) microm, (17.0 +/- 2.6) microm, and (11.0 +/- 2.5) microm, respectively. At 3.5 hours after Boyden chamber assay, the cell count of each group with 0, 0.1, 1, 10, 20 micromol/L gefitinib was 69.2 +/- 7.0, 51.8 +/- 7.5, 43.8 +/- 8.7, 30.6 +/- 4.8, and 28.4 +/- 3.4, respectively. Compared with the control group (0 micromol/L gefitinib), gefitinib could significantly prolong the wound-healing time and decrease the migrating cell count (P < 0.05), and significantly inhibit the lamellipodium formation, cell skeleton remolding and changes of the cytoskeleton polarization.</p><p><b>CONCLUSIONS</b>Gefitinib can reduce the migration capacity of triple-negative breast cancer cells through inhibiting phosphorylation of EGFR/PI3K/Akt pathway, suppressing the cell skeleton (microfilaments) remolding and changes of its polarization.</p>

Bcl-2 inhibitor ABT-737 enhances the cisplatin-induced apoptosis in breast cancer T47D cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the effect of ABT-737 combined with cisplatin on apoptosis of breast cancer cell line T47D cells.</p><p><b>METHODS</b>T47D cells cultured in vitro was used for this experiment. Cell proliferation was measured by MTT assay. The expression of apoptosis-related protein was determined by Western blot. Morphological changes of apoptotic cells were observed by fluorescence microscopy. The apoptosis rate was examined by flow cytometry.</p><p><b>RESULTS</b>The MTT assay showed that ABT-737 significantly decreased the IC(50) of cisplatin in T47D cells [(26.00 ± 1.41) µmol/L of single cisplatin vs. (13.00 ± 1.11) µmol/L of combination (ABT-737 + cisplatin)]. As a single agent, ABT-737 did not inhibit the proliferation of T47D cells, but enhanced the inhibitory effect of cisplatin in a dose-dependent manner. The detection of the cleavage of PARP showed that ABT-737 lowered the doses of cisplatin to induce apoptosis and shortened the induction time of apoptosis in T47D cells. Compared with the single use of cisplatin, the combination of ABT-737 and cisplatin accelerated the cleavage of PARP and caspase3, but did not alter the expression levels of Bcl-2, Bcl-X(L), and Bax. Both flow cytometry and fluorescence microscopy showed that ABT-737 combined with cisplatin significantly increased the apoptosis induction in T47D cells (2.3% ± 0.1 % in the control, 30.0% ± 0.8% in the cisplatin alone, and 49.0% ± 0.5% in the cisplatin + ABT-737 groups, P < 0.05).</p><p><b>CONCLUSION</b>The Bcl-2 inhibitor ABT-737 can significantly enhance cisplatin-induced apoptosis in human breast cancer T47D cells in vitro.</p>

Clinical impact of extracapsular extension of axillary lymph node metastases in breast cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the clinical significance of extracapsular extension (ECE) of axillary lymph node metastases in breast cancer.</p><p><b>METHODS</b>The clinicopathological data of 1230 cases of nodal positive breast cancer treated in our department from 1989 to 1995 were analyzed retrospectively.</p><p><b>RESULTS</b>486 (39.5%) from the 1230 cases were ECE positive. There was a higher incidence of ECE in postmenopausal women than premenopausal ones (47.5% versus 35.5%, respectively, P < 0.001). The patients in ECE positive group had a larger tumor size (5.11 +/- 2.53 cm versus 3.90 +/- 1.80 cm, P < 0.001). 18.3% of patients with stage T1 were ECE positive, stage T2 were 36.4%, and stage T3 were 54.4%, and the difference was significant (P < 0.001). ECE was correlated with the number of positive axillary lymph nodes. The ECE positive group had more positive nodes than ECE negative group (16.96 +/- 12.16 versus 5.24 +/- 6.60, P < 0.001). 6.1% of patients with 1 positive node were ECE positive, 13.5% with 2 - 3, 35.8% with 4 - 9, 62.3% with 10 - 19, and 84.0% with more than 20 positive axillary nodes, and there was a significant difference among those groups (P < 0.001). ECE had no association with ER/PR status (P = 0.706). ECE was a risk factor of local-regional recurrence, but the relapse time had no significant difference (P = 0.559). ECE was also a risk factor of distant metastasis, and the relapse time had a significant difference (P < 0.001). The median metastasis free time was 30.0 (2 approximately 172) months in ECE positive group, while 37.5 (2 approximately 170) months in ECE negative group (P = 0.006). CE occurred in 60.4% of the patients with firstly diagnosed bone, skin and distant lymph node metastasis, but in 42.0% of the patients with firstly diagnosed visceral metastasis (P = 0.001). The metastasis-free survival rate, locoregional recurrence-free survival rate and overall survival rate of the ECE positive group were much shorter than that of the ECE negative group. COX proportional hazard regression single factor analysis and multi-factor analysis suggested that ECE is an independent factor of metastasis-free survival, locoregional free recurrence and overall survival.</p><p><b>CONCLUSION</b>The presence of ECE in breast cancer is positively related with tumor size and the number of positive lymph nodes. It is also a risk factor of locoregional recurrence and distant metastasis. ECE positive group has a much shorter metastasis-free survival, locoregional recurrence-free survival and overall survival. ECE is a risk factor of those three indexes.</p>