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>

Effects of Akt inhibitor MK2206 on proliferation and apoptosis of breast cancer cells / 肿瘤

Objective: To study the effects of Akt inhibitor MK2206 on the proliferation and apoptosis of human breast cancer cell lines T47D and MDA-MB-231, and to elucidate the possible mechanism of such effects. Methods: Human breast cancer T47D and MDA-MB-231 cells were treated with different concentrations of MK2206, respectively. The inhibitory effect of MK2206 on cell proliferation was examined by MTT assay. The apoptosis rates of T47D and MDA-MB-231 cells induced by MK2206 were detected by flow cytometry (FCM). The expression levels of caspase-3, poly (ADP-ribose) polymerase (PARP), bcl-2, bax, phosphorate-AKT (p-AKT) and total Akt (T-Akt) proteins were detected by Western blotting. Results: The proliferation of T47D and MDA-MB-231 cells were inhibited after treatment with MK2206 at 0.1, 1, 10 and 100 nmol/L for 24 h, respectively. The apoptosis rates of T47D and MDAMB-231 cells were increased induced by MK2206. The expression levels of caspase-3, PARP and bax proteins were up-regulated, while the expression levels of bcl-2 and p-Akt proteins were downregulated. All of these effects occurred in a dose-dependent manner. MK2206 had no significant effect on the expression of T-Akt. Conclusion: MK2206 can inhibit the proliferation and induce the apoptosis in human breast cancer cell lines T47D and MDA-MB-231. These effects may be related with the downregulation of p-AKT and the inhibition of PI3K-Akt signaling pathway.

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>