Yu-Ching Wen

Inhibition of MDA-MB-231 breast cancer cell proliferation and tumor growth by apigenin through induction of G2/M arrest and histone H3 acetylation-mediated p21WAF1/CIP1 expression

Apigenin (4′,5,7‐trihydroxyflavone), a flavonoid commonly found in fruits and vegetables, has anticancer properties in various malignant cancer cells. However, the molecular basis of the anticancer effect remains to be elucidated. In this study, we investigated the cellular mechanisms underlying the induction of cell cycle arrest by apigenin. Our results showed that apigenin at the nonapoptotic induction concentration inhibited cell proliferation and induced cell cycle arrest at the G2/M phase in the MDA‐MB‐231 breast cancer cell line. Immunoblot analysis indicated that apigenin suppressed the expression of cyclin A, cyclin B, and cyclin‐dependent kinase‐1 (CDK1), which control the G2‐to‐M phase transition in the cell cycle. In addition, apigenin upregulated p21WAF1/CIP1 and increased the interaction of p21WAF1/CIP1 with proliferating cell nuclear antigen (PCNA), which inhibits cell cycle progression. Furthermore, apigenin significantly inhibited histone deacetylase (HDAC) activity and induced histone H3 acetylation. The subsequent chromatin immunoprecipitation (ChIP) assay indicated that apigenin increased acetylation of histone H3 in the p21WAF1/CIP1 promoter region, resulting in the increase of p21WAF1/CIP1 transcription. In a tumor xenograft model, apigenin effectively delayed tumor growth. In these apigenin‐treated tumors, we also observed reductions in the levels of cyclin A and cyclin B and increases in the levels of p21WAF1/CIP1 and acetylated histone H3. These findings demonstrate for the first time that apigenin can be used in breast cancer prevention and treatment through epigenetic regulation.

Nonautophagic cytoplasmic vacuolation death induction in human PC-3M prostate cancer by curcumin through reactive oxygen species -mediated endoplasmic reticulum stress

The antiapoptotic and antiautophagic abilities of cancer cells constitute a major challenge for anticancer drug treatment. Strategies for triggering nonapoptotic or nonautophagic cell death may improve therapeutic efficacy against cancer. Curcumin has been reported to exhibit cancer chemopreventive properties. Herein, we report that curcumin induced apoptosis in LNCaP, DU145, and PC-3 cells but triggered extensive cytoplasmic vacuolation in PC-3M cells. Electron microscopic images showed that the vacuoles lacked intracellular organelles and were derived from the endoplasmic reticulum (ER). Moreover, curcumin-induced vacuolation was not reversed by an apoptosis- or autophagy-related inhibitor, suggesting that vacuolation-mediated cell death differs from classical apoptotic and autophagic cell death. Mechanistic investigations revealed that curcumin treatment upregulated the ER stress markers CHOP and Bip/GRP78 and the autophagic marker LC3-II. In addition, curcumin induced ER stress by triggering ROS generation, which was supported by the finding that treating cells with the antioxidant NAC alleviated curcumin-mediated ER stress and vacuolation-mediated death. An in vivo PC-3M orthotopic prostate cancer model revealed that curcumin reduced tumor growth by inducing ROS production followed by vacuolation-mediated cell death. Overall, our results indicated that curcumin acts as an inducer of ROS production, which leads to nonapoptotic and nonautophagic cell death via increased ER stress.

Snail as a potential marker for predicting the recurrence of prostate cancer in patients at stage T2 after radical prostatectomy

BACKGROUND We retrospectively investigated the relationship between immunohistochemical staining of radical prostatectomy (RP) specimens for snail and cancer recurrence. METHODS Seventy-six patients with prostate cancer who underwent RP were enrolled, and 53 patients were ultimately collected whose cancer was pathologically defined as T2. We detected the expression of snail using tissue microarrays. The snail image score was determined by the intensity×tumor percentage, and a high score was defined as 8 (1-12 points). RESULTS The snail image scores and Gleason score sums were correlated with recurrence-free survival according to a log-rank test (p<0.05). In a Cox proportional hazard model, only a high snail image score (≥8) (hazard ratio (HR): 3.04, p=0.036) but not a high Gleason score sum (≥7) (HR: 1.33, p=0.215), and a more-advanced pathological T stage (T2c) (HR: 1.5, p=0.461) were significantly correlated with worse recurrence-free survival. The snail image score was determined to be an independent factor for predicting prostate cancer recurrence after RP. CONCLUSION In patients with pathological localized prostate cancer and a high snail image score in cancer tissue, adjuvant therapy might be suggested to prevent early biochemical failure.

Quercetin simultaneously induces G0/G1‐phase arrest and caspase‐mediated crosstalk between apoptosis and autophagy in human leukemia HL‐60 cells

Quercetin is a plant‐derived bioflavonoid with high anticancer activity in various tumors. Herein, the molecular mechanisms by which quercetin exerts its anticancer effects against HL‐60 acute myeloid leukemia (AML) cells were investigated. Results showed that quercetin suppressed cell proliferation in the HL‐60 cell line in vitro and in vivo. Quercetin‐induced G0/G1‐phase arrest occurred when expressions of cyclin‐dependent kinase (CDK)2/4 were inhibited and the CDK inhibitors, p16 and p21, were induced. Moreover, quercetin treatment not only activated proapoptotic signaling like poly (ADP ribose) polymerase (PARP)−1 cleavage and caspase activation but also triggered autophagy events as shown by the increased expression of light chain 3 (LC3)‐II, decreased expression of p62, and formation of acidic vesicular organelles. Interestingly, it was found that use of the autophagy inhibitor, 3‐methyladenine, significantly enhanced quercetin‐mediated apoptotic cell death as analyzed by MTS and DNA fragmentation assays. Moreover, pretreatment of HL‐60 cells with the pan‐caspase inhibitor, Z‐VAD‐fmk, dramatically reversed quercetin‐mediated apoptotic and autophagic cell death. Although apoptosis and autophagy are two independent cell death pathways, our findings indicated that quercetin can activate caspases to trigger these two pathways, and both pathways played contrary roles in quercetin‐mediated HL‐60 cell death. In conclusion, besides promoting apoptosis, quercetin also induced cytoprotective autophagy in HL‐60 cells, and inhibition of autophagy may be a novel strategy to enhance the anticancer activity of quercetin in AML.

Akt activation correlates with snail expression and potentially determines the recurrence of prostate cancer in patients at stage T2 after a radical prostatectomy

Our previous work demonstrated the epithelial-mesenchymal transition factor, Snail, is a potential marker for predicting the recurrence of localized prostate cancer (PCa). Akt activation is important for Snail stabilization and transcription in PCa. The purpose of this study was to retrospectively investigate the relationship between the phosphorylated level of Akt (p-Akt) in radical prostatectomy (RP) specimens and cancer biochemical recurrence (BCR). Using a tissue microarray and immunohistochemistry, the expression of p-Akt was measured in benign and neoplastic tissues from RP specimens in 53 patients whose cancer was pathologically defined as T2 without positive margins. Herein, we observed that the p-Akt level was higher in PCa than in benign tissues and was significantly associated with the Snail level. A high p-Akt image score (≥8) was significantly correlated with a higher histological Gleason sum, Snail image score, and preoperative prostate-specific antigen (PSA) value. Moreover, the high p-Akt image score and Gleason score sum (≥7) showed similar discriminatory abilities for BCR according to a receiver-operator characteristic curve analysis and were correlated with worse recurrence-free survival according to a log-rank test (p < 0.05). To further determine whether a high p-Akt image score could predict the risk of BCR, a Cox proportional hazard model showed that only a high p-Akt image score (hazard ratio (HR): 3.12, p = 0.05) and a high Gleason score sum (≥7) (HR: 1.18, p = 0.05) but not a high preoperative PSA value (HR: 0.62, p = 0.57) were significantly associated with a higher risk of developing BCR. Our data indicate that, for localized PCa patients after an RP, p-Akt can serve as a potential prognostic marker that improves predictions of BCR-free survival.

A Large Urinary Bladder Hemangioma Mimicking Urachal Cancer: A Case Report and Literature Review

Urinary bladder hemangiomas are rare, especially in children and adolescents. We present a case of a 17-year-old young man with persistent gross hematuria for 1 month. Computed tomography revealed a 3.6 cm mass on the superior anterior wall of the urinary bladder, which was highly suspected as an urachal tumor. We carried out an en bloc resection of the urachus and bladder tumor. The pathologic report indicated a cavernous hemangioma of the urinary bladder. No tumor recurrence or bleeding was found during the 2-year follow-up. Urinary bladder hemangioma is an important differential diagnosis in young patients with hematuria.

Do 5α-reductase inhibitors prevent secondary benign prostate hyperplasia-related urinary retention?

Objective: The objective of this study is to determine whether 5α-reductase inhibitors (5ARIs) prevent secondary benign prostate hyperplasia (BPH)-related acute urinary retention (AUR) after the first episode of urine retention. Materials and Methods: In total, 1161 patients were enrolled using the International Classification of Diseases, Ninth Revision (ICD-9) codes as having AUR (ICD-9 code 788.20) and BPH, with or without lower urinary tract symptoms (ICD-9 codes 600.0 and 600.1) between January 2006 and June 2016. After excluding patients with bladder and external sphincter dysfunction, we enrolled 128 patients in this study. Patients were divided into two groups: Group 1 comprising 33 patients receiving 5ARI (dutasteride) and α-blocker treatment, and Group 2 comprising 95 patients receiving α-blocker treatment alone. Patient characteristics, namely, age, prostate size, maximal urinary flow rate (Qmax), prostate-specific antigen (PSA) level, and duration of dutasteride treatment, were recorded and compared. Patients were followed for at least 6 months to a maximum period of 24 months if no event occurred. Events of secondary BPH-related AUR and surgery were recorded. Results: All patient characteristics, except for prostate size, were similar between the two groups (Group 1 vs. Group 2: 65.0 vs. 36.9 mL, P = 0.001). In total, 43 patients (32%) experienced secondary AUR within 24 months. The rate of secondary BPH-related AUR was significantly lower in the Group 1 than in the Group 2 (18.2% vs. 39.4%, P = 0.030). The rate of BPH-related surgery was lower in the Group 1 (9.1% vs. 14.9%, P = 0.410), although the difference was not significant. Prostate size and PSA levels were significantly lower in the Group 1 (23.5%) than in the Group 2 (60.4%) (P < 0.001). Conclusions: Using 5ARIs to treat patients with first episodes of BPH-related AUR significantly prevents secondary AUR.

Dopamine receptor D2 genetic variations is associated with the risk and clinicopathological variables of urothelial cell carcinoma in a Taiwanese population

Dopamine receptor D2 (DRD2) is overexpressed in several kinds of cancers and was correlated with the prognosis of these cancers. Polymorphisms within the DRD2 gene were shown to be associated with lung and colon cancers. The purpose of this study was to explore effects of DRD2 gene polymorphisms on the susceptibility to and clinicopathological characteristics of urothelial cell carcinoma (UCC). In total, 369 patients diagnosed with UCC and 738 healthy controls were enrolled to analyze DRD2 genotypes at four loci (rs1799732, -141C>del; rs1079597, TaqIB; rs6277, 957C>T; and rs1800497, TaqIA) using a TaqMan-based real-time polymerase chain reaction (PCR). We found a significantly lower risk for UCC in individuals with the DRD2 rs6277 CT genotype compared to those with the wild-type CC genotype (adjusted odds ratio (AOR)=0.405, 95% confidence interval (CI): 0.196~0.837, p=0.015). In 124 younger patients (aged < 65 years) of the recruited UCC cohort, patients who carried at least one T allele of DRD2 rs1800497 were at higher risk (AOR=2.270, 95% CI: 1.060~4.860, p=0.033) of developing an invasive stage (pT2~pT4). In 128 female patients of the recruited UCC cohort, patients who carried at least one deletion allele of DRD2 rs1799732 showed a higher incidence of having an invasive stage (AOR=2.585, 95% CI: 1.066~6.264, p=0.032) and a large tumor (AOR=2.778, 95% CI: 1.146~6.735, p=0.021). Further analyses of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets revealed correlations of the expression of DRD2 with an invasive tumor, tumor metastasis, and the lower survival rate in patients with UCC. Our findings suggest that DRD2 levels might affect the progression of UCC, and the polymorphisms rs6277, rs1800497, and rs1799732 of DRD2 are probably associated with the susceptibility and clinicopathologic development of UCC in a Taiwanese population.

N-α-acetyltransferase 10 protein promotes metastasis by stabilizing matrix metalloproteinase-2 protein in human osteosarcomas

N-α-Acetyltransferase 10 protein (Naa10p) mediates N-terminal acetylation of nascent proteins. Oncogenic or tumor suppressive roles of Naa10p were reported in cancers. Here, we report an oncogenic role of Naa10p in promoting metastasis of osteosarcomas. Higher NAA10 transcripts were observed in metastatic osteosarcoma tissues compared to non-metastatic tissues and were also correlated with a worse prognosis of patients. Knockdown and overexpression of Naa10p in osteosarcoma cells respectively led to decreased and increased cell migratory/invasive abilities. Re-expression of Naa10p, but not an enzymatically inactive mutant, relieved suppression of the invasive ability in vitro and metastasis in vivo imposed by Naa10p-knockdown. According to protease array screening, we identified that matrix metalloproteinase (MMP)-2 was responsible for the Naa10p-induced invasive phenotype. Naa10p was directly associated with MMP-2 protein through its acetyltransferase domain and maintained MMP-2 protein stability via NatA complex activity. MMP-2 expression levels were also significantly correlated with Naa10p levels in osteosarcoma tissues. These results reveal a novel function of Naa10p in the regulation of cell invasiveness by preventing MMP-2 protein degradation that is crucial during osteosarcoma metastasis.