Rhein activated Fas-induced apoptosis pathway causing cardiotoxicity in vitro and in vivo.

Rhein, one of the main active components of rhubarb (Dahuang) and Polygonum multiflorum (Heshouwu), has a wide range of effective pharmacological effects. Recently, increasing studies have focused on its potential hepatorenal toxicity, but the cardiotoxicity is unknown. In this study, we found that the IC50 of rhein to H9c2 cells at 24 h and 48 h were 94.5 and 45.9µmol/L, respectively, with positive correlation of dose-toxicity and time-toxicity. After the treatment of rhein (106, 124 and 132µmol/L), the number of H9c2 cells decreased significantly, and the morphology of H9c2 cells showed atrophy, round shape and wall detachment. Moreover, the proportion of apoptotic cells in H9c2 cells treated with rhein was significantly increased in a dose-dependent manner. And rhein induced S phase arrest of H9c2 cells and inhibited cell proliferation. Rhein up-regulated ROS, LDH levels and low MMP but down-regulated SOD content in H9c2 cells. Additionally, the results showed that the cardiac function LVEF and LVFS of rhein high-medium-low dose groups (350, 175, 87.5 mg/kg) were significantly reduced. And the contents of Ca2+, cTnT, CK and LDH in serum of KM mice were significantly up-regulated by rhein. Furthermore, western blot results suggested that rhein the above effects via promoting Fas-induced apoptosis pathway in vitro and in vivo. In general, rhein may cause cardiotoxicity via Fas-induced apoptosis pathway in vivo and in vitro, which provides reference for the safe use of medicinal plant containing rhein and its preparations.

Erianin inhibits human lung cancer cell growth via PI3K/Akt/mTOR pathway in vitro and in vivo.

Erianin is a small-molecule compound that is isolated from Dendrobium chrysotoxum Lindl. In recent years, it has been found to have evident antitumor activity in various cancers, such as bladder cancer, cervical cancer, and nasopharyngeal carcinoma. In this study, we assessed the effect of erianin on lung cancer in terms of cell growth inhibition and the related mechanism. First, erianin at a concentration of less than 1 nmol/L exhibited cytotoxicity in H1975, A549, LLC lung cancer cells, did not cause marked growth inhibition in normal lung and kidney cells, induced obvious apoptosis and G2/M phase arrest of cells, and inhibited the migration and invasion of lung cancer cells in vitro. Second, in a mouse xenograft model of lewis lung cancer (LLC), oral administration of erianin (50, 35, and 10 mg kg-1  day-1 for 12 days) substantially inhibited nodule growth, reduced the fluorescence counts of lewis cells and the percentage vascularity of tumor tissues, increased the number of apoptotic tumor cells, the thymus indices, up-regulated the levels of interleukin (IL)-2 and tumor necrosis factor-α (TNF-α), decreased IL-10 levels and the spleen index, and enhanced immune function. Lastly, the possible targets of erianin were determined by molecular docking and verified via western blot assay. The results indicated that erianin may achieve the above effects via inhibiting the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway in vitro and vivo. Taken together, the results showed that erianin had obvious antitumor effects via inhibiting the PI3K/Akt/mTOR pathway in vitro and vivo and may have potential clinical value for the treatment of lung cancer.

miR-29a regulated ER-positive breast cancer cell growth and invasion and is involved in the insulin signaling pathway.

Increasing amounts of evidence show that insulin can activate different insulin signaling pathways to promote breast cancer growth and invasion. miR-29a plays crucial roles in decreasing glucose-stimulated insulin secretion, as well as in regulating breast cancer cell proliferation and EMT. However, the mechanism responsible for the regulatory effects of miR-29a on breast cancer growth and invasion and the relationship between these effects and insulin signaling remains unclear. Herein, we showed that human insulin increased miR-29a expression in ER-positive breast cancer cells and that miR-29a facilitated the ability of insulin to promote breast cancer cell proliferation and migration. We found that miR-29a-induced cell proliferation and metastasis acceleration occurred primarily through ERK phosphorylation. The IGF-1R is the upstream target gene of miR-29a, while CDC42 and p85α are the downstream target genes of miR-29a. These results have provided us with information regarding the molecular mechanisms by which hyperinsulinemia promotes breast cancer occurrence and development and thus leads to a poor prognosis in breast cancer patients and indicate that miR-29a plays an important role in breast cancer development and invasion.

miR-34a expression in human breast cancer is associated with drug resistance.

miR-34a is significantly down-regulated in breast cancer tissues and cell lines, which may be correlated with breast cancer multi-drug resistance (MDR). Here, we conducted cell-based experiments and clinical studies in a cohort of 113 breast cancer samples to analyze miR-34a expression and breast cancer MDR. Expression of miR-34a is down-regulated in the multi-drug resistant MDR-MCF-7 cells compared with its parental cells. Patients with miR-34a low expression had poorer overall survival (OS) and disease free survival (DFS) in comparison with those with high expression. Transfecting miR-34a mimics into MDR-MCF-7 breast cancer cells led to partial MDR reversal. Compared with the control group, miR-34a significantly reduced both the mRNA and protein expressions of BCL-2, CCND1 and NOTCH1, but no obvious changes were found in P53 or TOP-2a expression. In breast cancer tissue samples, the expression of miR-34a was related to BCL-2, CCND1 and NOTCH1, but not to HER-2, P53 and TOP-2a. Altogether, our findings suggest that miR-34a is an MDR and prognosis indicator of breast cancer, which may participate in the regulation of drug-resistant breast cancer by targeting BCL-2, CCND1, and NOTCH1.

[Correlation between Tau expression and clinicopathological characteristics of breast invasive ductal carcinomas].

OBJECTIVE: To explore the expression of Tau protein in breast invasive ductal carcinomas and examine the correlation between its expression and clinicopathological characteristics of breast cancer. METHODS: The clinicopathological data of 150 breast cancer patients at Third Municipal Hospital from October 2007 to June 2011 were collected and analyzed. Immunohistochemical method was used to detect the expressions of estrogen receptor (ER), progesterone receptor (PR), HER-2 and Tau protein. RESULTS: No correlations existed between the expression of Tau protein and age, tumor size or node metastasis of breast cancer patients (χ(2) = 0.02, P = 0.88; χ(2) = 0.55, P = 0.46; χ(2) = 1.02, P = 0.31). The expressions of Tau in ER positive patients were significantly higher than ER negative patients. And this trend extended to PR positive and HER-2 negative patients (χ(2) = 15.77, P = 0.00; χ(2) = 5.03, P = 0.03; χ(2) = 8.00, P = 0.01). The expression of Tau protein in Luminal A subtype was significantly higher than in Luminal B subtype, HER-2 over-expression subtype and basal like subtype (χ(2) = 7.26, P = 0.01). CONCLUSIONS: Over-expressed in breast cancer, Tau protein is associated with ER, PR and HER-2. However, the relation between Tau protein and prognosis of breast cancer requires further researches.

Tau proteins expressions in advanced breast cancer and its significance in taxane-containing neoadjuvant chemotherapy.

Tau is a microtubule-associated protein and expressed in normal breast epithelial cells and breast cancer. Tau expression in breast cancer may be important for chemotherapy optimization. This study is to investigate the expression of Tau in advanced breast cancer and its significance in taxane-containing neoadjuvant chemotherapy. Levels of Tau protein in advanced breast cancer were detected immunohistochemically. The chemotherapeutic efficacy indexes in Tau(-) group, which includes the remission rate, Miller-Payne pathological reactive grade, and pathologic complete response rate, were improved compared with that in Tau(+) group. There was difference in the efficacy indexes among ER+ subgroups but not among ER- patients. In addition, Tau expression was positively correlated (r = 0.32, P < 0.00). In multivariate analysis, when age, clinical stage, postoperative lymph node metastasis, ER, PR, HER2, Ki-67, TP53, or Tau status were included, postoperative lymph node metastasis and Tau-negative status were identified as independent predictors of pathologic complete response. In conclusion, negative Tau protein expression may be an effective predictor for taxane-containing neoadjuvant chemotherapy, especially in ER+ subgroups. Further study on the molecular mechanism and utility of Tau for individualizing adjuvant chemotherapy is warranted.