BACKGROUND: The loss of estrogen and progesterone receptors appears to be associated with a progression to less-differentiated and hormone-independent tumors. The gain of hormone independency over time even in estrogen receptor-positive tumors has become another obstacle to endocrine therapy for breast cancer. We tried to regain the hormone dependency in estrogen receptor-negative breast cancer cells by lipofecting estrogen receptor cDNA. MATERIALS AND METHODS: The mutant human estrogen receptor cDNA (pSG5-HE0) was lipofected into estrogen receptor-negative human breast cancer cell line MDA-MB-231, in an attempt to restore their sensitivity to antiestrogen. Then the effects if 17 beta -estradiol and tamoxifen were studied by counting viable cell numbers after treating the lipofected cell line with either one or together. RESULTS: The cell growth was most profoundly inhibited in 4 days after lipofection with mutant human estrogen receptor cDNA, which was overcome after that days. Tamoxifen, as an antiestrogen, showed a growth inhibitory effect slightly strong over combined conditions of tamoxifen and 17 beta estradiol compared to estrogen-treated group and to control. CONCLUSIONS: The temporary induction of estrogen receptor by lipofection with pSG5-HE0 on estrogen receptor-negative human breast cancer cell line MDA-MB-231 showed negative growth control on these cells by tamoxifen, indicating that liposome-mediated estrogen receptor transfection may be used as a novel therapeutic strategy for hormone independent human breast cancers in the near future.
Breast Neoplasms* ; Breast* ; Cell Count ; Cell Line ; DNA, Complementary ; Estradiol ; Estrogen Receptor Modulators ; Estrogens* ; Genetic Therapy ; Humans* ; Receptors, Progesterone ; Tamoxifen* ; Transfection

There are some controversial opinions on the prognostic value of metastasis-associated tumor markers in breast cancer. Out of them, the overexpression of c-erbB-2 proto-oncogene or CD44 gene has been debated on their activities in promoting metastatic potential. To determine the relationship between expression of both genes, and, clinicopathological parameters and disease outcomes including relapse and survival, 48 archival paraffin-embedded breast-cancer tissues were stained using monoclonal antibody against each gene product by immunohistochemical staining method, and the result was analyzed. The positive expression rates of c-erbB-2 and CD44 genes were 45.8% and 18.8%, respectively. The co-expression rates of both positives and both negatives were 14.6% and 50.0%, respectively. Except the statistically significant positive correlation between CD44 and tumor size (P=0.003), the expression rates of c-erbB-2 and CD44 had no significant relationship with tumor size, stge, lymph node status, and disease recurrence (p>0.05). In the positive expression cases for CD44, disease-free survival (DFS) and overall survival (OS) in months were shorter than the negative ones (53+/-8 vs. 64+/-5 and 67+/-8 vs. 77+/-5 S.E.) And, the c-erbB-2 positive cases had longer OS than the negative ones (78+/-6 vs. 71+/-6). The OS of positive co-expression cases with the c-erbB-2 and CD44 was shorter than that of one-gene expression ones (66+/-6 vs. 75+/-7). So the OS result observed in the expression of c-erbB-2 alone was reversed in the co-expression study. Though these results had no statistically significant level (p>0.05), we suggest a question that if there is any interaction or dependency between c-erbB-2 and CD44 expression in a view of disease process including OS. Finally, further randomized controlled studies are advisable for the reproducible and significant results.
Breast Neoplasms* ; Breast* ; Disease-Free Survival ; Genes, erbB-2 ; Lymph Nodes ; Recurrence ; Biomarkers, Tumor

BACKGROUND: Metastatic breast cancer is a systemic disease, and its treatment aims at the palliation or cure of the disease. In recent years, good results have been reported in the treatment of metastatic breast cancer by using single-agent paclitaxel chemotherapy. METHODS: We performed a retrospective study by analyzing the medical records of patients treated at Kangnam St. Mary's Hospital between May 1995 and May 1997. A total of 29 patients with metastatic breast cancer were treated by a 135-mg/m2, 3-hour infusion of paclitaxel. The results were reviewed with respect to the response rates and the toxicities of paclitaxel. RESULTS: The overall response rate was 13.8%: CR (complete response rate) 3.4% (1 out of 29) and PR (partial response rate) 10.3%(3 out of 29). The most common and severe toxicity was leukopenia. However, there was no mortality, and the patients were tolerated this therapy. CONCLUSIONS: Paclitaxel as a single-agent therapy for metastatic breast cancer is tolerable, but less effective, than reported.
Breast Neoplasms* ; Breast* ; Drug Therapy ; Humans ; Leukopenia ; Medical Records ; Mortality ; Paclitaxel* ; Retrospective Studies