Yi-Hung Kuo

Metastatic lymph node ratio is a more precise predictor of prognosis than number of lymph node metastases in stage III colon cancer

ObjectiveThe objective of this study is to assess the value of metastatic lymph node ratio (LNR) in predicting disease-free survival (DFS) in patients with stage III adenocarcinoma of the colon.Materials and methodsFrom 1995 to 2003 inclusively, a total of 624 patients featuring stage III adenocarcinoma of the colon underwent curative resection. Of the 624 patients, an adequate number of lymph nodes (n ≥ 12) had been harvested in 490 patients. These patients were stratified into LNR groups 1 (LNR ≤ 0.4), 2 (0.4 < LNR ≤ 0.7), and 3 (LNR > 0.7). Kaplan–Meier survival curve and log-rank test were used to evaluate the prognostic value of LNR. A Cox regression model was used for multivariate analyses.ResultsThe 5-year DFS rate was 66.7% for patients with LNR1, 35.1% for those with LNR2, and 0% for patients with LNR3 (p < 0.0001). In T3/4LNR1 patients (n = 411), there was no difference in survival between those with N1 stage and those with N2 stage. Cox proportional hazards regression analysis revealed that N stage (number of positive lymph nodes) was not a significant factor when LNR was taken into consideration.ConclusionsLNR is a more precise predictor of 5-year DFS than number of positive lymph nodes (N stage) in patients with stage III colon cancer.

Proteomic analysis of the effects of baicalein on colorectal cancer cells.

Baicalein is the flavonoids with multiple pharmacological activities. The aim of our study was to investigate the effects of baicalein on colorectal cancer (CRC) and to recognize the targets of baicalein treatment. To better understand baicaleins target, proteomic approaches were used to purify and identify the protein substrates using 2D difference gel electrophoresis (2D SDS‐PAGE) to elucidate proteins differential display. Results from this study investigate that baicalein treatment of CRC cells results in reduced cell proliferation. As a result, differential protein displays between baicalein‐treated and untreated CRC were determined and validated. There were 11 differentially expressed proteins between baicalein‐treated and untreated CRC. Furthermore, we demonstrate that baicalein inhibits cancer cell proliferation and reduced reactive oxygen species (ROS) by up‐regulating the levels of peroxiredoxin‐6 (PRDX6). Knockdown of PRDX6 in baicalein‐treated CRC cells by specific small interfering RNA resulted in ROS production and proliferation, opposite of the baicalein treatment scenario as indicated by cell cycle distribution. These results illustrate that baicalein up‐regulates the expression of PRDX6, which attenuates the generation of ROS and inhibits the growth of CRC cells, whereas baicalein treatment have no effect on normal epithelial cells.

Resistin-induced stromal cell-derived factor-1 expression through Toll-like receptor 4 and activation of p38 MAPK/ NFκB signaling pathway in gastric cancer cells

BackgroundStromal cell-derived factor-1 (SDF-1) (CXC chemokine ligand-12)/CXC chemokine receptor 4 (CXCR4) is involved in the carcinogenesis of human gastric cancer, where it stimulates angiogenesis and favors metastasis of tumor cells to distant organs. In addition, resistin is suggested to be an important link between obesity and the development of gastric cancer. Resistin has identified as an important player in inflammatory responses, and emerged as a mediator in inflammation-associated cancer. A limited number of studies have investigated the association of resistin and SDF-1 with gastric cancer. Herein, we investigated the molecular mechanisms by which resistin influences the expression of SDF-1 in gastric carcinoma cells.ResultsHuman gastric cancer cell lines were exposed to doses of resistin; SDF-1 expression and secretion levels were then determined. Real-time polymerase chain reaction and western blotting analyses were performed to clarify molecular changes. Inhibition of Toll-like receptor 4 (TLR4) by a competitive antagonist inhibited resistin-induced SDF-1 expression. Pharmacological inhibitors and small interfering RNA (siRNA) demonstrated that activation of the p38 mitogen-activated protein kinase (MAPK) pathway is critical for resistin-induced SDF-1 expression mediated by TLR4. The promoter activity and transcription factor enzyme-linked immunosorbent assay revealed that resistin induced expression of SDF-1 mediated by NF-κB in gastric cancer cells. Inhibition of p38 MARK activation blocked the SDF-1-induced expression and the SDF-1 promoter activity in the cancer gastric cells. Chromatin immunoprecipitation assay revealed that inhibition of p38 MARK activation also blocked the resistin-increased NF-κB-DNA-binding activity.ConclusionsResistin-induced SDF-1 upregulation by activation of TLR4, p38 MARK and NF-κB may explain a new role of resistin in the link of obesity and gastric cancer.

Stromal cell‐derived factor‐1/CXC receptor 4 and β1 integrin interaction regulates urokinase‐type plasminogen activator expression in human colorectal cancer cells

The stromal cell‐derived factor‐1 (SDF‐1)/CXC receptor 4 (CXCR4) axis has been shown to play a role in colorectal cancer progression. In addition, the protease urokinase‐type plasminogen activator (uPA) is an important factor in tumor cell invasion and metastasis. However, the mechanism by which SDF‐1 mediates uPA expression in human colorectal cancer cells remains unknown. We investigated the molecular mechanism governing the interaction between SDF‐1 stimulation and uPA expression in three human colon cancer cell lines (DLD‐1, SW48, and COLO 205). We found that SDF‐1 stimulation led to an increase in the expression and secretion of uPA in these cells. Experiments involving specific inhibitors and small interfering RNA demonstrated that the activation of p38 mitogen‐activated protein kinase (MAPK) and phosphatidylinositol 3‐kinase (PI3K)/Akt pathways are critical for SDF‐1‐induced uPA expression. Analysis of transcription factor binding using ELISA and chromatin immunoprecipitation assays revealed that SDF‐1 increased Sp1‐ and AP‐1‐DNA‐binding activities in DLD‐1 cells. Inhibition of Sp1 and AP‐1 activation blocked the SDF‐1‐induced expression and activity of the uPA promoter. The effect of SDF‐1 on DLD‐1 signaling and uPA expression was mediated by the CXCR4/β1 integrin axis. In summary, our findings elucidate the mechanisms of SDF‐1/CXCR4 downstream signaling and provide insights into the function of SDF‐1 in colon cancer cells. J. Cell. Physiol. 227: 1114–1122, 2012.

Role of body mass index in colon cancer patients in Taiwan

AIM To determine the effect of body mass index (BMI) on the characteristics and overall outcome of colon cancer in Taiwan. METHODS From January 1995 to July 2003, 2138 patients with colon cancer were enrolled in this study. BMI categories (in kg/m²) were established according to the classification of the Department of Health of Taiwan. Postoperative morbidities and mortality, and survival analysis including overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS) were compared across the BMI categories. RESULTS There were 164 (7.7%) underweight (BMI < 18.5 kg/m²), 1109 (51.9%) normal-weight (BMI = 18.5-23.9 kg/m²), 550 (25.7%) overweight (BMI = 24.0-26.9 kg/m²), and 315 (14.7%) obese (BMI ≥ 27 kg/m²) patients. Being female, apparently anemic, hypoalbuminemic, and having body weight loss was more likely among underweight patients than among the other patients (P < 0.001). Underweight patients had higher mortality rate (P = 0.007) and lower OS (P < 0.001) and DFS (P = 0.002) than the other patients. OS and DFS did not differ significantly between normal-weight, overweight, and obese patients, while CSS did not differ significantly with the BMI category. CONCLUSION In Taiwan, BMI does not significantly affect colon-CSS. Underweight patients had a higher rate of surgical mortality and a worse OS and DFS than the other patients. Obesity does not predict a worse survival.

Selective β2-AR Blockage Suppresses Colorectal Cancer Growth Through Regulation of EGFR-Akt/ERK1/2 Signaling, G1-Phase Arrest, and Apoptosis.

The stress‐upregulated catecholamines‐activated β1‐ and β2‐adrenergic receptors (β1/2‐ARs) have been shown to accelerate the progression of cancers such as colorectal cancer (CRC). We investigated the underlying mechanism of the inhibition of β1/2‐ARs signaling for the treatment of CRC and elucidated the significance of β2‐AR expression in CRC in vitro and in clinical samples. The impacts of β1/2‐AR antagonists in CRC in vitro and CRC‐xenograft in vivo were examined. We found that repression of β2‐AR but not β1‐AR signaling selectively suppressed cell viability, induced G1‐phase cell cycle arrest, caused both intrinsic and extrinsic pathways‐mediated apoptosis of specific CRC cells and inhibited CRC‐xenograft growth in vivo. Moreover, the expression of β2‐AR was not consistent with the progression of CRC in vitro or in clinical samples. Our data evidence that the expression profiles, signaling, and blockage of β2‐AR have a unique pattern in CRC comparing to other cancers. β2‐AR antagonism selectively suppresses the growth of CRC accompanying active β2‐AR signaling, which potentially carries wild‐type KRAS, in vitro and in vivo via the inhibition of β2‐AR transactivated EFGR‐Akt/ERK1/2 signaling pathway. Thus, β2‐AR blockage might be a potential therapeutic strategy for combating the progressions of β2‐AR‐dependent CRC. J. Cell. Physiol. 231: 459–472, 2016.

The Association of CXC Receptor 4 Mediated Signaling Pathway with Oxaliplatin-Resistant Human Colorectal Cancer Cells.

The stromal cell–derived factor-1 (SDF-1)/CXC receptor 4 (CXCR4) axis plays an important role in tumor angiogenesis and invasiveness in colorectal cancer (CRC) progression. In addition, metastatic CRC remains one of the most difficult human malignancies to treat because of its chemoresistant behavior. However, the mechanism by which correlation occurs between CXCR4 and the clinical response of CRC to chemotherapy remains unknown. We generated chemoresistant cells with increasing doses of oxaliplatin (OXA) and 5-Fluorouracil (5FU) to develop resistance at a clinical dose. We found that the putative markers did not change in the parental cells, but HCT-116/OxR and HCT-116/5-FUR were more aggressive and had higher tumor growth (demonstrated by wound healing, chemotaxis assay, and a nude mice xenograft model) with the use of oxaliplatin. Apoptosis induced by oxaliplatin treatment was significantly decreased in HCT-116/OxR compared to the parental cells. Moreover, HCT-116/OxR cells displayed increased levels of p-gp, p-Akt p-ERK, p-IKBβ, CXCR4, and Bcl-2, but they also significantly inhibited the apoptotic pathways when compared to the parental strain. We evaluated the molecular mechanism governing the signaling pathway associated with anti-apoptosis activity and the aggressive status of chemoresistant cells. Experiments involving specific inhibitors demonstrated that the activation of the pathways associated with CXCR4, ERK1/2 mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3-kinase (PI3K)/Akt is critical to the functioning of the HCT-116/OxR and HCT-116/5-FUR characteristics of chemosensitivity. These findings elucidate the mechanism of CXCR4/PI3K/Akt downstream signaling and provide strategies to inhibit CXCR4 mediated signaling pathway in order to overcome CRC’s resistance to chemotherapy.

Metastasis at the Colostomy Site: A Rare Case Report

Metastasis at the colostomy site is rare. Most reported patients with such metastases undergo abdominoperineal resection and this kind of metastases happened after a longer period post-cancer surgery. In our patient, because it happened during a short interval between rectal cancer surgery and stoma closure, colostomy site metastasis probably occurred owing to ablative cancer cell reflux and seeding from the obstruction during decompressive colostomy rather than local, lymphatic or haematogenous spread. Meticulous histologic analyses to rule out undetected, concomitant polyps and metachronous cancer are very important for patients with obstructive colorectal cancer who undergo decompressive colostomy. The potential risk of colostomy site metastasis during staged surgery for obstructive colorectal cancer remains uncertain; however, the result from this case report raises the question of such a risk for further studies in a greater number of patients.

CIL-102-Induced Cell Cycle Arrest and Apoptosis in Colorectal Cancer Cells via Upregulation of p21 and GADD45

CIL-102 (1-[4-(furo[2,3-b]quinolin-4-ylamino)phenyl]ethanone) is a well-known, major active agent of the alkaloid derivative of Camptotheca acuminata with valuable biological properties, including anti-tumorigenic activity. In this study, we investigated the molecular mechanisms by which CIL-102 mediated the induction of cell death, and we performed cell cycle G2/M arrest to clarify molecular changes in colorectal cancer cells (CRC). Treatment of DLD-1 cells with CIL-102 resulted in triggering the extrinsic apoptosis pathway through the activation of Fas-L, caspase-8 and the induction of Bid cleavage and cytochrome c release in a time-dependent manner. In addition, CIL-102 mediated apoptosis and G2/M arrest by phosphorylation of the Jun N-terminus kinase (JNK1/2) signaling pathway. This resulted in the expression of NFκB p50, p300 and CREB-binding protein (CBP) levels, and in the induction of p21 and GADD45 as well as the decreased association of cdc2/cyclin B. Furthermore, treatment with the JNK1/2 (SP600125), NFκB (PDTI) or the p300/CBP (C646) inhibitors abolished CIL-102-induced cell cycle G2/M arrest and reversed the association of cdc2 with cyclin B. Therefore, we demonstrated that there was an increase in the cellular levels of p21 and GADD45 by CIL-102 reduction in cell viability and cell cycle arrest via the activation of the JNK1/2, NFκB p50, p300 and CBP signaling modules. Collectively, our results demonstrated that CIL-102 induced cell cycle arrest and apoptosis of colon cancer cells by upregulating p21 and GADD45 expression and by activating JNK1/2, NFκB p50 and p300 to provide a new mechanism for CIL-102 treatment.

Interleukin-17 induces CC chemokine receptor 6 expression and cell migration in colorectal cancer cells.

The CC chemokine receptor 6 (CCR6) and its ligand CCL20 are involved in human colorectal cancer (CRC) carcinogenesis and can promote the progression of CRC. In addition, interleukin‐17 (IL‐17), produced by a T cell subset named “Th17,” has been identified as an important player in inflammatory responses, and has emerged as a mediator in inflammation‐associated cancer. However, the relevance of IL‐17 in the development and progression of CRC still remains to be explored. This study aimed to investigate the effect of IL‐17 on the cell migration of CRC cells. Human CRC HCT‐116 cells were used to study the effect of IL‐17 on CCR6 expression and cell migration in CRC cells. IL‐17 treatment induced migration of HCT‐116 cells across the Boyden chamber membrane and increased the expression level of the CCR6. Inhibition of CCR6 by small interfering RNA (siRNA) and neutralizing antibody inhibited IL‐17‐induced cell migration. By using specific inhibitors and short hairpin RNA (shRNA), we demonstrated that the activation of ERK and p38 pathways are critical for IL‐17‐induced CCR6 expression and cell migration. Promoter activity and transcription factor ELISA assays showed that IL‐17 increased NF‐κB‐DNA binding activity in HCT‐116 cells. Inhibition of NF‐κB activation by specific inhibitors and siRNA blocked the IL‐17‐induced CCR6 expression. Our findings support the hypothesis that CCR6 up‐regulation stimulated by IL‐17 may play an active role in CRC cell migration. J. Cell. Physiol. 230: 1430–1437, 2015.