Comparative efficacy of extracts from Lycium barbarum bark and fruit on estrogen receptor positive human mammary carcinoma MCF-7 cells.

Chemo-endocrine therapy for estrogen receptor positive (ER(+)) breast cancer exhibits acquired tumor resistance. Herbal medicines provide integrative support for breast cancer patients. Present study compared the efficacy of aqueous extracts from Lycium barbarum bark (LBB) and Lycium barbarum fruit (LBF) on ER(+) MCF-7 cells. Cellular growth and 17ß-estradiol (E2) metabolism quantified the efficacy. MCF-7 cells maintained in serum depleted medium+ E2 exhibited increased anchorage-dependent and anchorage-independent growth. LBB exhibited greater potency than LBF (95% reduction in IC50). LBB produced a 6.8-fold increase, 40% decrease, and a 3.7-fold increase in 2-hydroxyestrone (2-OHE1), 16α-hydroxyestrone (16α-OHE1), and estriol (E3) formation. The corresponding values for LBF were 3.9, 33, and 10.5. LBB produced a16.3-fold and a twofold increase in 2-OHE1:16α-OHE1 and E3:16α-OHE1 ratios, whereas LBF produced a sixfold and a 2.9-fold increase. The efficacy of LBB is due to increased 2-OHE1 formation, whereas that of LBF is due to accelerated conversion of 16α-OHE1 to E3. Specific growth inhibitory profiles of LBB and LBF may be due to their distinct chemical composition and their complementary actions on E2 metabolism. This study validates a mechanistic approach to identify efficacious herbal extracts for clinical ER(+) breast cancer.

Growth Inhibitory Efficacy of Chinese Herbs in a Cellular Model for Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is characterized by the absence of estrogen receptor-α progesterone receptor and human epidermal growth factor receptor-2. Treatment for this breast cancer subtype is restricted to multidrug chemotherapy and survival pathway-based molecularly targeted therapy. The long-term treatment options are associated with systemic toxicity, spontaneous and/or acquired tumor resistance and the emergence a of drug-resistant stem cell population. These limitations lead to advanced stage metastatic cancer. Current emphasis is on research directions that identify efficacious, naturally occurring agents representing an unmet need for testable therapeutic alternatives for therapy resistant breast cancer. Chinese herbs are widely used in traditional Chinese medicine in women for estrogen related health issues and also for integrative support for cancer treatment. This review discusses published evidence on a TNBC model for growth inhibitory effects of several mechanistically distinct nontoxic Chinese herbs, most of them nutritional in nature, and identifies susceptible pathways and potential molecular targets for their efficacy. Documented anti-proliferative and pro-apoptotic effects of these herbs are associated with downregulation of RB, RAS, PI3K, and AKT signaling, modulation of Bcl-2/BAX protein expressions and increased caspase activity. This review provides a proof of concept for Chinese herbs as testable alternatives for prevention/therapy of TNBC.

Lycium barbarum inhibits growth of estrogen receptor positive human breast cancer cells by favorably altering estradiol metabolism.

Selective estrogen receptor modulators represent accepted therapy for estrogen receptor positive (ER+) breast cancer, exhibit adverse side effects, and reduce patient compliance. The use of phytoestrogen containing herbal medicines is limited because of efficacy and safety concerns. The ER+ MCF-7 model examined growth inhibitory effects of the medicinal herb Lycium barbarum (LB) and identified mechanistic leads for its efficacy. The MCF-7 cells maintained in 0.7% serum (17beta-estradiol, E2 < 1 nM) exhibited 11%-87% increased growth after treatment with 1nM to 20 nM E2. Growth promotion with 20 nM E2 exhibited 5.2-fold increased estrone (E1), 35.7% increased 2-hydroxyestrone (2-OHE1), 15.4% increased 16alpha-hydroxyestrone (16alpha-OHE1), and eightfold increased estriol (E3) formation. Treatment of E2 stimulated cells with LB exhibited a dose-dependent growth inhibition of 9.5%-42.8% at Day 3 and 33.9%-83.9% at Day 7. The 3-day inhibitory response to 1% LB (maximum cytostatic concentration) exhibited 84.8% increased E1, 3.6-fold increased 2-OHE1, 33.3% decreased 16alpha-OHE1, and 9.2-fold increased E3 formation. Thus, MCF-7 cells retain their mitogenic and metabolic response to E2 and LB downregulates E2-stimulated growth via the formation of antiproliferative 2-OHE1 and accelerated conversion of mitogenic 16alpha-OHE1 to antimitogenic E3.

Growth inhibitory efficacy of Cornus officinalis in a cell culture model for triple-negative breast cancer.

Triple-negative breast cancer (TNBC) lacks the expressions of estrogen receptor-α, progesterone receptor and human epidermal growth factor receptor-2. The treatment options for TNBC include anthracyclin/taxol based conventional chemotherapy and small molecular inhibitor based targeted therapy. However, the therapeutic efficacy is limited by systemic toxicity and acquired tumor resistance; identification of less toxic testable alternatives is urgently required. Non-toxic nutritional herbs are commonly used in traditional Chinese herbal medicine for general health management and may additionally represent a testable therapeutic alternative for TNBC. The present study examined the growth inhibitory efficacy of the nutritional herb Cornus officinalis (CO) in MDA-MB-231 cells, which represent a cell culture model for TNBC, and identified potential mechanistic leads. In MDA-MB-231 cells, CO induced dose-dependent cytostatic growth arrest [inhibitory concentration (IC)50, 0.1% and IC90, 0.5%], and inhibited anchorage independent colony formation. Mechanistically, CO inhibited G1 to S phase transition leading to G1 arrest and decreased the expression of cyclin D1 and phosphorylated-retinoblastoma proteins. CO additionally altered apoptosis specific BCL-2 associated X protein/B-cell lymphoma-2 expression and upregulated pro-apoptotic caspase-3/7 activity. Collectively, these data provided mechanistic evidence for the efficacy of CO, and validated a mechanism-based approach to prioritize efficacious nutritional herbs as testable alternatives for secondary prevention/treatment of TNBC.

Growth inhibitory efficacy and anti-aromatase activity of Tabebuia avellanedae in a model for post-menopausal Luminal A breast cancer.

Aromatase inhibitors (AIs) represent a treatment option for post-menopausal estrogen receptor-positive (ER+) breast cancer as monotherapy, or in combination with cyclin-dependent kinase 4/6 or mTOR inhibitors. Long-term treatment with these agents leads to dose-limiting toxicity and drug resistance. Natural substances provide testable alternatives to current therapy. Tabebuia avellanedae (TA) tree is indigenous to the Amazon rainforest. The inner bark of TA represents a medicinal dietary supplement known as Taheebo. Non-fractionated aqueous extract from TA is an effective growth inhibitor in the Luminal A and triple negative breast cancer models. The quinone derivative naphthofurandione (NFD) is a major bioactive agent in TA. The present study examined the efficacy of finely ground powder from the inner bark of TA, available under the name of Taheebo-NFD-Marugoto (TNM). The ER+ MCF-7 cells stably transfected with the aromatase gene MCF-7AROM represented a model for aromatase-expressing post-menopausal breast cancer. Anchorage-independent colony formation, cell cycle progression, pro-apoptotic caspase 3/7 activity, apoptosis-specific gene expression, aromatase activity and select estradiol (E2) target gene expression represented the mechanistic end points. Treatment of MCF-7AROM cells with TNM induced a dose-dependent reduction in E2-promoted anchorage-independent colony number. Mechanistic assays on TNM-treated MCF-7AROM cells demonstrated that TNM at a concentration of 10 µg (NFD content: 2 ng), induced S-phase arrest, increased pro-apoptotic caspase 3/7 activity, increased pro-apoptotic BAX and decreased anti-apoptotic BCL-2 gene expression, and inhibited aromatase activity. Additionally, TNM treatment downregulated ESR-1 (gene for ER-α), aromatase and progesterone gene expression and reduced mRNA levels of E2 target genes pS2, GRB2 and cyclin D1. Inhibition of aromatase activity, based on the NFD content of TNM was superior to the clinical AIs Letrozole and Exemestane. These data demonstrated the potential efficacy of TNM as a nutritional alternative for current therapy of aromatase positive, post-menopausal breast cancer.

A pooled analysis of bone marrow micrometastasis in breast cancer.

BACKGROUND: We assessed the prognostic significance of the presence of micrometastasis in the bone marrow at the time of diagnosis of breast cancer by means of a pooled analysis. METHODS: We combined individual patient data from nine studies involving 4703 patients with stage I, II, or III breast cancer. We evaluated patient outcomes over a 10-year follow-up period (median, 5.2 years), using a multivariable piecewise Cox regression model. RESULTS: Micrometastasis was detected in 30.6 percent of the patients. As compared with women without bone marrow micrometastasis, patients with bone marrow micrometastasis had larger tumors and tumors with a higher histologic grade and more often had lymph-node metastases and hormone receptor-negative tumors (P<0.001 for all variables). The presence of micrometastasis was a significant prognostic factor with respect to poor overall survival and breast-cancer-specific survival (univariate mortality ratios, 2.15 and 2.44, respectively; P<0.001 for both outcomes) and poor disease-free survival and distant-disease-free survival during the 10-year observation period (incidence-rate ratios, 2.13 and 2.33, respectively; P<0.001 for both outcomes). In the multivariable analysis, micrometastasis was an independent predictor of a poor outcome. In the univariate subgroup analysis, breast-cancer-specific survival among patients with micrometastasis was significantly shortened (P<0.001 for all comparisons) among those receiving adjuvant endocrine treatment (mortality ratio, 3.22) or cytotoxic therapy (mortality ratio, 2.32) and among patients who had tumors no larger than 2 cm in diameter without lymph-node metastasis and who did not receive systemic adjuvant therapy (mortality ratio, 3.65). CONCLUSIONS: The presence of micrometastasis in the bone marrow at the time of diagnosis of breast cancer is associated with a poor prognosis.

The nutritional herb Epimedium grandiflorum inhibits the growth in a model for the Luminal A molecular subtype of breast cancer.

The Luminal A subtype of breast cancer expresses the estrogen receptor (ER)-α and progesterone receptor (PR), but not the human epidermal growth factor receptor (HER)-2 oncogene. This subtype of breast cancer responds to endocrine therapy involving the use of selective estrogen receptor modulators and/or inhibitors of estrogen biosynthesis. However, these therapeutic agents are frequently associated with long-term systemic toxicity and acquired tumor resistance, emphasizing the need to identify non-toxic alternative treatments for chemo-endocrine therapy responsive breast cancer. The present study utilized the human mammary carcinoma-derived, ER+/PR+/HER-2- MCF-7 cell line as a model of the Luminal A subtype of breast cancer to examine the growth inhibitory effect of the Chinese nutritional herb Epimedium grandiflorum (EG) and determine the mechanisms underlying this effect. MCF-7 cells maintained in a serum-depleted culture medium retained their ability to grow in response to 17ß-estradiol (E2). Treatment of the MCF-7 cells with EG resulted in dose-dependent inhibition of E2-promoted growth. Mechanistically, EG inhibited E2-promoted cell cycle progression through G1 stage arrest and modulated the cellular metabolism of E2, increasing the formation of the anti-proliferative metabolites 2-hydroxyestrone and estriol. Long-term treatment of MCF-7 cells with EG inhibited E2-promoted anchorage independent growth, a surrogate in vitro biomarker of tumorigenesis. In conclusion, the results of the present study demonstrate the growth inhibitory effects of EG on MCF-7 cells and identified clinically relevant mechanistic leads for its anti-tumorigenic efficacy.