Ching Shyang Chen

Overexpression and Activation of the α9-Nicotinic Receptor During Tumorigenesis in Human Breast Epithelial Cells

BACKGROUND Large epidemiological cohort studies in the United States have indicated that active and passive smoking are associated with increased breast cancer risk. However, there was no direct evidence of an effect of tobacco carcinogens on the cellular molecules involved in breast tumorigenesis. METHODS Reverse transcription-polymerase chain reaction was used to determine the expression of all of the nicotinic acetylcholine receptor (nAChR) subunits in 50 human breast cancer samples and to determine the expression of the alpha9-nAChR subunit in 276 surgical and laser capture microdissected breast tumor vs normal tissue pairs. Stable MDA-MB-231 breast cancer cell lines were established in which expression of the alpha9-nAChR subunit was inhibited using short interfering RNA. MCF-10A normal human breast epithelial cells were established in which the alpha9-nAChR subunit could be conditionally overexpressed by removal of doxycycline from the culture fluid. Cell proliferation and soft agar assays and tumor growth in nude mice were used as measures of cell transformation. All statistical tests were two-sided. RESULTS In 186 (67.3%) of the 276 paired samples, alpha9-nAChR mRNA was expressed at (mean 7.84-fold) higher levels in breast cancers than in surrounding normal tissue. Stable expression of alpha9-nAChR short interfering RNA in MDA-MB-231 cells attenuated nicotine-stimulated proliferation and growth in soft agar and reduced tumor volume when the cells were introduced as xenografts in SCID mice (n = 5 mice per group; mean tumor volume at 6 weeks treatment in mice injected with Si alpha9 cells = 995.6 mm(3), in mice injected with parental cells = 2993.2 mm(3), difference = 1997.6 mm(3), 95% confidence interval [CI] = 1705 to 2290.2 mm(3), P = .009). Long-term treatment of MCF-10A normal breast epithelial cells with either nicotine or its active metabolite, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, triggered precancerous transformation as defined by soft agar assay. Inducible overexpression of alpha9-nAChR in MCF-10A cell xenografts in nude mice substantially increased tumor growth (n = 5 mice per group; DOX+, mean tumor volume without nicotine vs with nicotine = 266.2 vs 501.6 mm(3), difference = 235.4 mm(3), 95% CI = 112.7 to 358 mm(3), P = .009; DOX-, mean tumor volume without nicotine vs with nicotine = 621.2 vs 898.6 mm(3), difference = 277.4 mm(3), 95% CI = 98.1 to 456.7 mm(3), P = .016; mean tumor volume in the presence of nicotine, DOX+ vs DOX- = 501.6 vs 898.6 mm(3), difference = 397 mm(3), 95% CI = 241.3 to 552.6 mm(3), P = .009). CONCLUSION The alpha9-nAChR is important for nicotine-induced transformation of normal human breast epithelial cells.

Tea polyphenol (−)‐epigallocatechin‐3‐gallate inhibits nicotine‐ and estrogen‐induced α9‐nicotinic acetylcholine receptor upregulation in human breast cancer cells

SCOPE The aim of this research was to explore whether the tea-polyphenol (-)-epigallocatechin-3-gallate (EGCG) could be used as a potential agent for blocking smoking (nicotine, Nic)- or hormone (estradiol, E2)-induced breast cancer cell proliferation through inhibition of a common signaling pathway. METHODS AND RESULTS To explore whether Nic (>0.1 μM, 24 h) and E2 (>1 nM, 24 h) significantly increased α9-nicotinic acetylcholine (α9-nicotinic acetylcholine receptor (nAChR)) mRNA and protein expression levels, real-time PCR and immunoblotting analysis experiments were performed in human breast cancer (MCF-7) cells. Luciferase promoter activity experiment was performed to test the α9-nAChR promoter activity affected by Nic, E2 or EGCG. The results indicate that treatment with EGCG (1 μM) profoundly decreases Nic- and E2-induced MCF-7 proliferation by down regulating α9-nAChR expression. The α9-nAChR promoter activity is significantly induced by 24-h treatment with Nic (10 μM) or E2 (10 nM) (>1.8 and ∼2.3-fold, respectively) in MCF-7 cells. Pretreatment with EGCG eliminated the Nic- and E2-induced α9-nAChR promoter-dependent luciferase activity. We further demonstrate that combined treatment with EGCG profoundly inhibits [3H]-Nic/ α9-nAChR binding activity in breast cancer cells. CONCLUSIONS We found that the EGCG could be used as an agent for blocking smoking (Nic)- or hormone (E2)-induced breast cancer cell proliferation by inhibiting of α9-nAChR signaling pathway. This study reveals the novel antitumor mechanisms of EGCG, and these results may have significant applications for chemopreventive purposes in human breast cancer.

Combination Treatment with Luteolin and Quercetin Enhances Antiproliferative Effects in Nicotine-Treated MDA-MB-231 Cells by Down-regulating Nicotinic Acetylcholine Receptors

Large-scale epidemiological cohort studies performed in the United States indicate that breast cancer risk is associated with active and passive smoking. As of yet, however, there is no direct evidence of antitumor effects by agents that block the effect of tobacco compound nicotine (Nic) on relevant nicotinic receptors (nAChR) involved in breast tumorigenesis. In the present study, the expression profiles of different nAChR subunits in the human breast cancer cell line (MDA-MB-231) were characterized by RT-PCR. Nic (>0.1 microM, 6 h) significantly increased alpha9-nAChR mRNA and protein expression levels in human breast cancer cells (MDA-MB-231 cells). On the other hand, combined treatment with luteolin (Lut, 0.5 microM) and quercetin (Que, 0.5 microM) profoundly decreased MDA-MB-231 proliferation by down-regulating alpha9-nAChR expression. MDA-MB-231 cells were cultured in soft agar to evaluate anchorage-independent colony formation; combined treatment of Lut+Que inhibited Nic-induced MDA-MB-231 colony formation. Interestingly, the number of colonies formed was profoundly reduced in alpha9-nAChR knockdown (Si alpha9) cells in the combined (Lut+Que)-treated group as compared to the relevant control groups. Such results show that Lut- or Que-induced antitransforming activities were not limited to specific inhibition of the alpha9-nAChR receptor. Both alpha5- and alpha9-nAChR appear to be important molecular targets for Lut- and Que-induced antitumor effects in human breast cancer cells.

NF-κB-activated tissue transglutaminase is involved in ethanol-induced hepatic injury and the possible role of propolis in preventing fibrogenesis

The increased expression and cross-linking activity of tissue transglutaminase (tTG) have been demonstrated in acute liver injury and fibrosis. We focused on the molecular mechanisms that contribute to ethanol-induced tTG expression and investigated the efficacy of propolis components in preventing both the tTG expression in vitro and fibrogenesis in vivo. We demonstrate herein that both ERK1/2 and PI3K/Akt pathways can regulate the effects of ethanol on NF-kappaB-dependent transcription and these signaling pathways may be involved in activation of ethanol-mediated tTG expression. We also found that administration of pinocembrin (PIN), one of the major components of propolis, inhibited tTG activation and significantly prevented the development of thioacetamide (TAA)-induced liver cirrhosis. The present study suggests that tTG may be an important member of the cascade of factors necessary for ethanol-induced liver fibrogenesis and PIN could serve as an anti-fibrogenic agent.

Mucinous cystadenocarcinoma of the breast coexisting with infiltrating ductal carcinoma

A recently described and rare variant of breast carcinoma, mucinous cystadenocarcinoma (MCA), is reported in a 65‐year‐old post‐menopausal woman. She presented with a gradually enlarged breast tumor. A well‐circumscribed tumor measuring about 3 cm in diameter was noted in the mammographic and ultrasonographic examinations. The mammographic and ultrasonographic findings were indistinguishable from more common mucinous carcinoma (colloid carcinoma) of the breast. The gross appearance of the tumor was well‐defined and cystic, consisting of abundant transparent to bloody mucin, as well as whitish solid parts. Microscopically, the tumor was characterized by abundant extracellular and intracellular mucin. It looked like a mucinous cystic neoplasm of the ovary and pancreas. Particularly, few microscopic foci of ordinary intermediate‐grade infiltrating ductal carcinoma (IDC) and ductal carcinoma in situ (DCIS) were observed around the main lesion in this case. A transition from ordinary DCIS to MCA in situ was found. It might indicate MCA derives from a metaplasia process of ordinary DCIS. MCA can be easily differentiated from mucinous carcinoma by quite different histologic and immunohistochemical findings. According to the previously reported and present cases, MCA of the breast more commonly affects elderly women and has a relatively favorable prognosis.

Is Breast MRI Screening More Effective Than Digital Mammography in Asian Women

Background/Purpose The incidence of breast cancer in Taiwan is increasing, and this form of cancer has already become the number one malignancy. Taiwanese women share similar characteristics of breast cancer with other developed Asian countries such as a younger age at diagnosis. In addition, a large proportion of Asian women have dense glandular breast tissue, which lowers the sensitivity of mammography for cancer detection. In this study, we compared possible differences in image interpretation of digital mammography and a dedicated breast magnetic resonance imaging system (using spiral RODEO). Methods From March 2008 to April 2009, we retrospectively collected data on 106 Taiwanese women who received both digital mammography and dedicated breast magnetic resonance imaging examinations in the same period. We divided these cases into non-dense and dense groups according to breast density, and compared the image interpretations based on the different modalities. Results There were statistically significant differences (p Conclusion Mammography may be useful for screening in non-dense breast tissue, but breast magnetic resonance imaging should be an additional screening tool in populations with dense breast tissue.

Adjuvant Trastuzumab for 6 Months is Effective in Patients with HER2-positive Stage II or III Breast Cancer

OBJECTIVE The optimal duration of adjuvant trastuzumab treatment in patients with HER2-positive breast cancer is not known. The aim of this study was to evaluate the efficacy of 6 months of adjuvant trastuzumab treatment in patients with stage II or III HER2-positive breast cancer. METHODS The records of patients with HER2-positive stage II or III breast cancer who were admitted to the Breast Center of Taipei Medical University Hospital and Yuans General Hospital between 2000 and 2008 were reviewed. All patients received adjuvant trastuzumab at an initial dose of 4 mg/kg followed by a maintenance dose of 2 mg/kg/week for 22 weeks in combination with chemotherapy. RESULTS A total of 51 patients were included with a mean age of 46.9 years. Approximately 55% of the patients had stage III disease. The mean follow-up time from initiation of treatment was 45.2 months (range, 0.9 to 85 months). During follow-up, 46 patients (90.2%) did not experience tumor recurrence. The mean estimated disease free survival was 80.2 months. The estimated 1- , 2-, 5-, and 7-year survival rates were 97.9%, 93.1%, 93.1%, and 93.1%, respectively. The most common adverse effects were gastrointestinal symptoms (21.6%), chills (17.6%), dizziness (9.8%), and bone pain (7.8%). No cardiac or hematologic adverse events occurred. CONCLUSION Adjuvant therapy with trastuzumab for 6 months resulted in a clinical benefit in patients with HER2-positive breast cancer.

The in vivo antitumor effects on human COLO 205 cancer cells of the 4,7-dimethoxy-5-(2-propen-1-yl)-1,3-benzodioxole (apiole) derivative of 5-substituted 4,7-dimethoxy-5-methyl-l,3-benzodioxole (SY-1) isolated from the fruiting body of Antrodia camphorate.

CONTEXT The compound 4,7-dimethoxy-5-(2-propen-1-yl)-1,3-benzodioxole (apiole) has been isolated from several different plant species, including Petroselinum sativum. Our recent study found that apiole is a chemical derivative of 4,7-dimethoxy-5-methyl-l,3-benzodioxole (SY-1), which has been isolated from dried Antrodia camphorata (AC ) fruiting bodies, a traditional Chinese medicine with antitumor properties. AIMS Our previous in vitro study demonstrated that apiole inhibits the growth of human colon (COLO 205) cancer cells through the arrest of the cell cycle in G0/G1 phase. The in vivo antitumor effects of apiole were evaluated in this study. SETTING AND DESIGN Apiole was administered to mice at 1-30 mg/kg body weight through intraperitoneal (I.P.) injection three times per week (defined as a dosage of 1×-30×). MATERIALS AND METHODS The in vivo antitumor effects of apiole were evaluated in mice with xenografts of COLO 205 cells. STATISTICAL ANALYSIS All of the data are reported as the means ± S.E. Comparisons were performed with a one-way analysis of variance (ANOVA) followed by a Fishers least significant difference test. Significance was defined as P < 0.05. RESULTS Apiole (> 1×) markedly decreased the growth of COLO 205 human colon cancer cell tumor xenografts in an athymic nude mouse model system through the up-regulation of cell cycle regulators, such as p53, p21/Cip1, and p27/Kip1. The apiole-induced increase in G0/G1 phase cell cycle regulators was also associated with a significant decrease in the expression of cyclins D1 and D3. Surprisingly, statistically significantly higher tumor volumes were observed in mice that received 5× apiole compared with 30× apiole-treated mice (P < 0.05). No gross signs of toxicity were observed (e.g., body weight changes, general appearance, or individual organ effects) in any group. CONCLUSIONS Our results show, for the first time, the promising antitumor effects of apiole against colon tumors in an in vivo xenograft model.

Can Breast Magnetic Resonance Imaging Demonstrate Characteristic Findings of Preoperative Ductal Carcinoma In Situ in Taiwanese Women

OBJECTIVE Magnetic resonance imaging (MRI) is more sensitive than mammography and sonography for breast cancer detection, but its diagnostic specificity is still being debated, and standardised criteria are lacking. METHODS This study used a dedicated breast MRI system with a Spiral RODEO pulse sequence, and applied postprocessing techniques including multiplanar reformation (MPR) with ductal orientation, early subtracted phase (ESP) and a postcontrast kinetic curve. We discuss the possible MRI/pathology correlations based on pathogenetic concepts. We retrospectively collected data from 13 cases of benign intraductal and early-stage malignant lesions to observe the capability of MPR, ESP and kinetic curve techniques to diagnose early lesions differentially. MRI features and pathological findings for these cases were collected. RESULTS Thirteen cases of ductal carcinoma in situ with MRI characteristics and pathological findings were identified. We analysed early ductal lesions, such as intraductal epithelial hyperplasia, intraductal papilloma, ductal carcinoma in situ and small focal invasive ductal carcinoma. Using MRI with MPR to demonstrate ductal orientation, we found 12 cases with a ductogram appearance and 6 with crossing-over glandular tissue. The tumour size estimated by MRI was accurate in 6 cases, but overestimated in seven. CONCLUSION Dedicated breast MRI with MPR, ESP and kinetic curve analyses might be helpful in defining some characteristics of early-stage malignant lesions.

Wound Closure after Thyroid and Parathyroid Surgery: A Meta-Analysis of Randomized Controlled Trials

Aims: Wound closure after thyroidectomy and parathyroidectomy is associated with patients’ satisfaction, perception of cosmetic appearance, and experience of postoperative pain. Subcutaneous sutures, clips, and tissue adhesive are the three major methods of wound closure. In this study, we conducted a meta-analysis of randomized controlled trials to evaluate the outcomes of these methods. Methods: Relevant studies published before December 2017 were identified from PubMed, Embase, Cochrane Library, Scopus, and the ClinicalTrials.gov registry. Individual effect sizes were standardized, and a meta-analysis was conducted to calculate the pooled effect size by using random-effect models. The primary outcome was the cosmetic appearance, which was evaluated 4 weeks, 6 weeks, and 6 months after surgery. The secondary outcomes were patient satisfaction, postoperative pain, and complications. Results: A total of nine trials with 612 patients were reviewed. No significant difference was observed in patient satisfaction, postoperative pain, and complications among the wound closure methods. However, according to surgeon assessment, the subcutaneous suture method resulted in a significantly more favorable cosmetic appearance than the clip method (mean difference: −1.47, 95% confidence interval: −2.72 to −0.23). Conclusion: In the current study, no differences were found in patient satisfaction and postoperative pain among the subcutaneous suture, clip, and tissue adhesive wound closure methods. However, surgeons provided a more favorable appraisal for the subcutaneous suture method because of the improved cosmetic appearance. The choice of the closure method should be based on surgeon’s preference and cost.