Xiaoli Kong

Huaier aqueous extract inhibits proliferation of breast cancer cells by inducing apoptosis

Aqueous extract of Trametes robiniophila murr (Huaier) has been commonly used in China for cancer complementary therapy in recent years; however, the mechanisms of its anticancer effects are largely unknown. In the present study, we aim to investigate its inhibitory effect on both MCF‐7 and MDA‐MB‐231 cells, and explore the possible mechanisms of its anticancer effect. Cell viability and motility were measured by MTT and invasive assays, migration and scratch assays in vitro, respectively. The distribution of cell cycle, PI‐Annexin‐V staining and Rhodamine 123 assay were analyzed by flow cytometry, and western blot were used to test the apoptotic pathways. We found that Huaier extract could strongly inhibit cell viability of MCF‐7 and MDA‐MB‐231 cells in a time‐ and dose‐dependent manner; however, MDA‐MB‐231 cells showed more susceptibility to the treatment. Furthermore, cell invasiveness and migration were also suppressed with exposure to Huaier extract. We also indicated that Huaier could induce G0/G1 cell‐cycle arrest, p53 accumulation and activation selectively in MCF‐7 cells. Inspiringly, the PI‐Annexin‐V staining assay and western blot analysis confirmed cell apoptosis executed by caspase‐3. Decreased mitochondrial membrane potential by Rhodamine 123 assay and down‐regulation of Bcl‐2 and up‐regulation of BCL2‐associated X protein (BAX) indicated that Huaier induced apoptosis through the mitochondrial pathway. Caspase activation during Huaier‐induced apoptosis was confirmed by pan‐caspase inhibitor, Z‐VAD‐fmk. As expected, the inhibitor decreased Huaier‐induced apoptosis in both cell lines. Based on our findings, Huaier can induce cell apoptosis in both ER‐positive and ER‐negative breast cancer cell lines and is an effective complementary agent for breast cancer treatment. (Cancer Sci 2010; 101: 2375–2383)

Metadherin enhances the invasiveness of breast cancer cells by inducing epithelial to mesenchymal transition

The epithelial–mesenchymal transition (EMT) is a process in which polarized epithelial cells are converted into motile mesenchymal cells. During cancer development, EMT is conducive to tumor dissemination and metastatic spread. While overexpression of metadherin (MTDH) in breast cancer cell lines and tissues has been found to be associated with aggressive tumor behavior, its precise role in invasion and metastasis is largely unknown. Here we report that MTDH overexpression could significantly enhance the invasion and migration of breast cancer cells by inducing EMT. Metadherin overexpression led to upregulation of mesenchymal marker fibronectin, downregulation of epithelial marker E‐cadherin, and the nuclear accumulation of beta‐catenin. Also, transcription factors Snail and Slug were upregulated in breast cancer cells overexpressing MTDH. Overexpression of MTDH enhanced the invasiveness and migration ability of breast cancer cells in vitro. In addition, overexpression of MTDH led to increased acquisition of CD44+/CD24−/low markers that are characteristic of breast cancer stem cells. We also showed that NF‐kappa was involved in the expression of EMT‐related markers. Taken together, our results suggest that MTDH could promote EMT in breast cancer cells in driving the progression of their aggressive behavior. (Cancer Sci 2011; 102: 1151–1157)

Metadherin Mediates Lipopolysaccharide-Induced Migration and Invasion of Breast Cancer Cells

Background Breast cancer is the most prevalent cancer in women worldwide and metastatic breast cancer has very poor prognosis. Inflammation has been implicated in migration and metastasis of breast cancer, although the exact molecular mechanism remains elusive. Principal Findings We show that the pro-inflammatory endotoxin Lipopolysaccharide (LPS) upregulates the expression of Metadherin (MTDH), a recently identified oncogene, in a number of breast cancer lines. Stable knockdown of MTDH by shRNA in human breast MDA-MB-231 cells abolishes LPS-induced cell migration and invasion as determined by several in vitro assays. In addition, knockdown of MTDH diminishes Nuclear Factor-kappa B (NF-κB) activation by LPS and inhibited LPS-induced IL-8 and MMP-9 production. Conclusions These results strongly suggest that MTDH is a pivotal molecule in inflammation-mediated tumor metastasis. Since NF-κB, IL-8 and MMP-9 play roles in LPS-induced invasion or metastasis, the mechanism of MTDH-promoted invasion and metastasis may be through the activation of NF-κB, IL-8 and MMP-9, also suggesting a role of MTDH in regulating both inflammatory responses and inflammation-associated tumor invasion. These findings indicate that MTDH is involved in inflammation-induced tumor progression, and support that MTDH targeting therapy may hold promising prospects in treating breast cancer.

Low-dose radiation-induced epithelial-mesenchymal transition through NF-κB in cervical cancer cells

Cervical cancer is the leading cause of death from cancer among women. Radiotherapy for cervical cancer is an effective treatment method; however, the response to radiotherapy varies among patients. Epithelial-mesenchymal transition (EMT) is a morphogenesis process involved in embryonic and organismal development. During tumour progression, EMT may enhance cancer cell invasion, promoting tumour metastasis. We hypothesised that EMT was involved in the enhanced invasiveness of cervical cancer cells after low-dose radiation and aimed to elucidate the underlying mechanism of this process in low-dose radiation of cervical cancer. The irradiated cells (FIR cells) were derived from the parental cells (N cells) with a cumulative dose of 75 Gy. After resting and reorganisation, the effect of low-dose radiation on the FIR cells was analysed. The expression of E-cadherin, N-cadherin and p65 was detected by real-time qPCR and western blotting in parental cancer cells and irradiated cancer cells. Motility was detected using the migration/invasion assay. After silencing of NF-κB p65 expression using siRNA against p65, the expression of E-cadherin and N-cadherin was examined by real‑time qPCR and western blotting. We found that low-dose radiation induced morphological changes of cells. The expression of epithelial markers was downregulated and mesenchymal markers were induced in irradiated cells, both of which are characteristics of EMT. Additionally, in irradiated cells, migration and invasion were enhanced and the expression of p65 was increased. To investigate whether p65 was involved in EMT, we silenced the expression of p65 in irradiated cells using siRNA and found that the features of EMT were suppressed. In summary, p65-regulated EMT induced by low-dose irradiation of cervical cancer cell lines promoted the invasiveness and metastasis of cervical cancer cells. The reversal of EMT may be a new therapeutic target for improving the effectiveness of radiotherapy for cervical cancer.

Trail resistance induces epithelial-mesenchymal transition and enhances invasiveness by suppressing PTEN via miR-221 in breast cancer.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively induce apoptosis of cancer cells and is verified effective to various cancers. However, a variety of breast cancer cell lines are resistant to TRAIL and the mechanisms of resistance are largely unknown. In our present experiment, we successfully utilized breast cancer cell line MDA-MB-231 to establish TRAIL-resistant cell line. We found resistance to TRAIL could induce epithelial-mesenchymal transition (EMT) and enhance invasiveness. We further demonstrated PTEN was down-regulated in TRAIL-resistant cells. Silencing miR-221, PTEN expression was up-regulated, the process of EMT could be reversed, and the ability of migration and invasion were correspondingly weakened. We also demonstrated knockdown of miR-221 could reverse resistance to TRAIL partially by targeting PTEN. Our findings suggest that resistance to TRAIL could induce EMT and enhance invasiveness by suppressing PTEN via miR-221. Re-expression of miR-221 or targeting PTEN might serve as potential therapeutic approaches for the treatment of Trail-resistant breast cancer.

Inhibition of metadherin sensitizes breast cancer cells to AZD6244

The development of systemic therapy drug resistance for breast cancer treatment is an ongoing problem, thus, so are the potential molecular mechanisms of it. AZD6244 is a novel ATP-uncompetitive inhibitor to MAP/ERK kinase (MEK) 1/2 which has been demonstrated to be potent, selective and safe in the clinical trials and previous studies. However, the precise role of resistance to AZD6244 is largely unknown. We and other groups have reported that the novel oncogene Metadherin (MTDH) is associated with multiple drug resistance, but there is no report about its role in treatment of AZD6244. Here we report that the resistance to AZD6244 can be reserved by downregulating MTDH in breast cancer cell lines. When the MTDH was downregulated, the breast cancer cells exhibited a significantly increased sensitivity to AZD6244 as measured by MTT assay. After treated with AZD6244 the MTDH-knockdown cells showed more apoptosis rate and growth inhibition. We also showed that knockdown of MTDH cannot only increase expression of FOXO3a but also activate it by promoting its translocation via MTDH/ERK1/2/FOXO3a pathway rather than MTDH/AKT/FOXO3a pathway. In conclusion knockdown MTDH can enhance the breast cancer cells sensitivity to AZD6244 via regulating the expression and activity of FOXO3a. These indicate us that MTDH is a candidate marker to predict the clinical efficacy of AZD6244 and targeting MTDH could overcome the resistance to AZD6244 in breast cancer cells.

Delay in Diagnosis and Treatment of Symptomatic Breast Cancer in China

AbstractBackground Delay in diagnosis and treatment of cancer may lead to advanced tumor characteristics and poor prognosis. Research and investigation from economically developing countries such as China are warranted to support these conclusions, so we studied the impact on prognosis of delays and factors predicting delay in symptomatic breast cancer patients in China.MethodsMedical records and follow-up information were collected. Variables including demographic data, and clinical and tumor characteristics, including patient age, menstrual status, residential status, initial symptom, profession, comorbidities, tumor size, lymph node metastasis, distant metastasis, history of breast disease, and family history of breast cancer, were analyzed, as was survival information.ResultsA total of 1,431 women diagnosed with breast cancers between 1998 and 2005 in Qilu Hospital were enrolled and studied. Delays in diagnosis and treatment were correlated with larger tumor size, lymph node metastasis, late tumor stage, and worse disease-free survival, as assessed by multivariate logistic regression and Kaplan–Meier regression models. Patient residential status, initial symptom, menopausal status, and history of breast disease were independent predictors of delay. Stratified multivariate analyses confirmed that age was not associated with delay.ConclusionsDelay in diagnosis and treatment predicts worse clinical outcomes. Improvement of medical service in rural areas, especially for premenopausal women, can decrease delays and benefit breast cancer patients.

53BP1 sensitizes breast cancer cells to 5-fluorouracil.

Chemoresistance of breast cancer is a worldwide problem for breast cancer and the resistance to chemotherapeutic agents frequently led to the subsequent recurrence and metastasis. In our previous study, we have found that 53BP1 showed a gradual decrease during the progression of breast cancer and loss of 53BP1 was associated with metastasis and poor prognosis in breast cancer. Here we aimed to reveal whether 53BP1 could sensitize breast cancer to 5-Fu. We found that ectopic expression of 53BP1 can significantly sensitize breast cancer cells to 5-Fu while knockdown of 53BP1 conferred the resistance. The in vivo experiments confirmed that overexpression of 53BP1 in combination with 5-Fu markedly inhibited growth of xenotransplanted tumors in nude mice when compared to either agent alone. Furthermore, we demonstrated that 53BP1 regulated the sensitivity to 5-Fu through thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPYD). The present studies provide a new clue that combination of 5-Fu and 53BP1 could be a potential novel targeted strategy for overcoming breast cancer chemoresistance.

LncRNA-CDC6 promotes breast cancer progression and function as ceRNA to target CDC6 by sponging microRNA-215: KONG et al.

Rapid proliferation and metastasis of breast cancers resulted in poor prognosis in clinic. Recent studies have proved that long noncoding RNAs (lncRNAs) were involved in tumor progression. In this study, we aimed to determine the roles and mechanisms of lncRNA–cell division cycle 6 (CDC6) in regulating proliferation and metastasis of breast cancer. Clinically, lncRNA–CDC6 was highly expressed in tumor tissues and was positively correlated with clinical stages of breast cancers. Functionally, the ectopic expression of lncRNA–CDC6 promoted proliferation via regulation of G1 phase checkpoint, and further promoting the migration capability. Moreover, lncRNA–CDC6 could function as competitive endogenous RNA (ceRNA) via directly sponging of microRNA‐215 (miR‐215), which further regulating the expression of CDC6. Taken together, our results proved that lncRNA–CDC6 could function as ceRNA and promote the proliferation and metastasis of breast cancer cells, which provided a novel prognostic marker for breast cancers in clinic.

Precise intraoperative sentinel lymph node biopsies guided by lymphatic drainage in breast cancer

The purpose of this study was to present a novel surgical method for intraoperative precise sentinel lymph node biopsy (SLNB) and to determine its clinical efficacy and sensitivity in breast cancer patients. The sentinel lymph nodes (SLNs) were preoperatively evaluated by axillary ultrasound. The intraoperative detection of SLNs was guided by lymphatic drainage pathway. The lymphatic vessels and SLNs were visualized. During operation, we searched for all the true SLNs (trSLNs), para-SLNs (paSLNs) and post-SLNs (poSLNs) followed lymphatic drainage ducts. After precisely locating the lymphatic channels and lymph node, all the lymph nodes that firstly receive lymphatic drainage are designated as trSLNs. We precisely distinguished the trSLNs, paSLNs and poSLNs. We found the average number of trSLNs ranged from1 to 6. In addition, we assessed the novel technique in a total of 125 breast cancer patients. trSLNs were successfully identified in all patients (detection rate: 100 %). The accuracy of trSLNs is 99.2%. Data from our study strongly suggest that our method is a feasible and effective for the detection of precise trSLNs in breast cancer with real-time observations. (ClinicalTrials.gov number, NCT02651142).The purpose of this study was to present a novel surgical method for intraoperative precise sentinel lymph node biopsy (SLNB) and to determine its clinical efficacy and sensitivity in breast cancer patients. The sentinel lymph nodes (SLNs) were preoperatively evaluated by axillary ultrasound. The intraoperative detection of SLNs was guided by lymphatic drainage pathway. The lymphatic vessels and SLNs were visualized. During operation, we searched for all the true SLNs (trSLNs), para-SLNs (paSLNs) and post-SLNs (poSLNs) followed lymphatic drainage ducts. After precisely locating the lymphatic channels and lymph node, all the lymph nodes that firstly receive lymphatic drainage are designated as trSLNs. We precisely distinguished the trSLNs, paSLNs and poSLNs. We found the average number of trSLNs ranged from1 to 6. In addition, we assessed the novel technique in a total of 125 breast cancer patients. trSLNs were successfully identified in all patients (detection rate: 100 %). The accuracy of trSLNs is 99.2%. Data from our study strongly suggest that our method is a feasible and effective for the detection of precise trSLNs in breast cancer with real-time observations. (ClinicalTrials.gov number, NCT02651142).