Taiga Chiyo

Antidiabetic drug metformin inhibits esophageal adenocarcinoma cell proliferation in vitro and in vivo.

Esophageal carcinoma is the eighth most common cancer worldwide and the sixth leading cause of cancer-related deaths, with one of the worst prognoses of any form of cancer. Treatment with the anti-diabetic drug metformin has been associated with reduced cancer incidence in patients with type 2 diabetes. This study therefore evaluated the effects of metformin on the proliferation, in vitro and in vivo, of human esophageal adenocarcinoma cells, as well as the microRNAs associated with the antitumor effects of metformin. Metformin inhibited the proliferation of the esophageal adenocarcinoma cell lines OE19, OE33, SK-GT4 and OACM 5.1C, blocking the G0 to G1 transition in the cell cycle. This was accompanied by strong reductions in G1 cyclins, especially cyclin D1, cyclin-dependent kinase (Cdk)4, and Cdk6, and decreases in retinoblastoma protein phosphorylation. In addition, metformin reduced the phosphorylation of epidermal growth factor receptor and insulin-like growth factor and insulin-like growth factor-1 receptor, as well as angiogenesis-related proteins, such as vascular endothelial growth factor, tissue inhibitor of metalloproteinases (TIMP)-1, and TIMP-2. Metformin also markedly altered microRNA expression. Treatment with metformin of athymic nude mice bearing xenograft tumors reduced tumor proliferation. These findings suggest that metformin may have clinical use in the treatment of esophageal adenocarcinoma.

Outcomes of gastrointestinal defect closure with an over-the-scope clip system in a multicenter experience: An analysis of a successful suction method

AIM To demonstrate the clinical outcomes of a multicenter experience and to suggest guidelines for choosing a suction method. METHODS This retrospective study at 5 medical centers involved 58 consecutive patients undergoing over-the-scope clips (OTSCs) placement. The overall rates of technical success (TSR), clinical success (CSR), complications, and procedure time were analyzed as major outcomes. Subsequently, 56 patients, excluding two cases that used the Anchor device, were divided into two groups: 14 cases of simple suction (SS-group) and 42 cases using the Twin Grasper (TG-group). Secondary evaluation was performed to clarify the predictors of OTSC success. RESULTS The TSR, CSR, complication rate, and median procedure time were 89.7%, 84.5%, 1.8%, and 8 (range 1-36) min, respectively, demonstrating good outcomes. However, significant differences were observed between the two groups in terms of the mean procedure time (5.9 min vs 14.1 min). The CSR of the SS- and TG-groups among cases with a maximum defect size ≤ 10 mm and immediate or acute refractory bleeding was 100%, which suggests that SS is a better method than TG in terms of time efficacy. The CSR in the SS-group (78.6%), despite the technical success of the SS method (TSR, 100%), tended to decrease due to delayed leakage compared to that in the TG-group (TSR, CSR; 88.1%), indicating that TG may be desirable for leaks and fistulae with defects of the entire layer. CONCLUSION OTSC system is a safe and effective therapeutic option for gastrointestinal defects. Individualized selection of the suction method based on particular clinical conditions may contribute to the improvement of OTSC success.

Galectin-9 suppresses the proliferation of gastric cancer cells in vitro

Gastric cancer is the second-leading cause of cancer-related mortality worldwide, and the prognosis of advanced gastric cancer remains poor. Galectin-9 (Gal-9) is a tandem-repeat-type galectin that has recently been demonstrated to exert anti-proliferative effects on various types of cancer cells. The aim of our present study was to evaluate the effects of Gal-9 on human gastric cancer cells and the expression levels of microRNAs (miRNAs) associated with the antitumor effects of Gal-9 in vitro. In our initial experiments, Gal-9 suppressed the proliferation of gastric cancer cell lines in vitro. Our data further revealed that Gal-9 increased caspase-cleaved keratin 18 (CCK18) levels in gastric cancer cells. Additionally, Gal-9 reduced the phosphorylation of vascular endothelial growth factor receptor-3 (VEGFR-3) and insulin-like growth factor-1 receptor (IGF-1R). Furthermore, miRNA expression levels were markedly altered with Gal-9 treatment in vitro. In conclusion, Gal-9 suppressed the proliferation of human gastric cancer cells by inducing apoptosis. These findings suggest that Gal-9 could be a potential therapeutic target in the treatment of gastric cancer.

Analysis of the amount of tissue sample necessary for mitotic count and Ki-67 index in gastrointestinal stromal tumor sampling

There are no established opinions concerning whether the amount of tissue affects the accuracy of histological analyses in gastrointestinal stromal tumors (GISTs). The aim of the present study was to investigate the appropriate amount of tissue sample needed for mitotic count based on the risk classification of GISTs and the Ki-67 index using the following three methods: endoscopic ultrasound-guided fine-needle aspiration (FNA), a novel sampling method called tunneling bloc biopsy (TBB), and biopsy forceps followed by TBB (Bf). Forty-three samples (12 FNA, 17 TBB and 14 Bf) diagnosed as GISTs by immunohistological analysis were utilized. The major and minor axes and overlay area of one piece of specimen (OPS) from the three sampling methods were measured using digital imaging software and were analyzed comparatively regarding the acquisition of histological data. The mean major and minor axes (mm) and overlay areas (mm2) were in the order of TBB > Bf > FNA. The evaluable rates by mitotic count and Ki-67 were, respectively, 75% (9/12) and 83.3% (10/12) for FNA samples, 100% (17/17) and 100% (17/17) for TBB samples, and 100% (14/14) and 100% (14/14) for Bf samples (P>0.05). Three FNA samples were judged unevaluable due to too small specimens in overall diagnosis including mitotic count and Ki-67, calculating the cut-off value for the overlay area of OPS as 0.17 mm2. Comparing the concordance rates between the pre- and post-operative samples, TBB samples was significantly better than FNA (P<0.05). Conclusively, while the amounts of tissues obtained by TBB and Bf are unnecessary for the histological assessment of mitotic count and Ki-67 index, developments of the FNA method are needed to minimize sample error. Considering the technical aspects, as well as the size of the specimens, could help to guide therapeutic planning and improve diagnostic yield for GI subepithelial tumors.

Angiotensin receptor blocker telmisartan inhibits cell proliferation and tumor growth of cholangiocarcinoma through cell cycle arrest

Cholangiocarcinoma (CCA) is at an advanced stage at the time of its diagnosis, and developing a more effective treatment of CCA would be desirable. Angiotensin II type 1 (AT1) receptor blocker (ARB), telmisartan may inhibit cancer cell proliferation, but the mechanisms by which telmisartan affects various cancers remain unknown. In this study, we evaluated the effects of telmisartan on human CCA cells and to assess the expression of microRNAs (miRNAs). We studied the effects of telmisartan on CCA cells using two cell lines, HuCCT-1 and TFK-1. In our experiments, telmisartan inhibited the proliferation of HuCCT-1 and TFK-1 cells. Additionally, telmisartan induced G0/G1 cell cycle arrest via blockade of the G0 to G1 cell cycle transition. Notably, telmisartan did not induce apoptosis in HuCCT-1 cells. This blockade was accompanied by a strong decrease in cell cycle-related protein, especially G1 cyclin, cyclin D1, and its catalytic subumits, Cdk4 and Cdk6. Telmisartan reduced the phosphorylation of EGFR (p-EGFR) and TIMP-1 by using p-RTK and angiogenesis array. Furthermore, miRNA expression was markedly altered by telmisartan in HuCCT-1. Telmisartan inhibits tumor growth in CCA xenograft model in vivo. In conclusion, telmisartan was shown to inhibit human CCA cell proliferation by inducing cell cycle arrest.

The angiotensin II type 1 receptor antagonist telmisartan inhibits cell proliferation and tumor growth of esophageal adenocarcinoma via the AMPKα/mTOR pathway in vitro and in vivo

Telmisartan, a widely used antihypertensive drug, is an angiotensin II type 1 (AT1) receptor blocker (ARB). This drug inhibits cancer cell proliferation, but the underlying mechanisms in various cancers, including esophageal cancer, remain unknown. The aim of the present study was to evaluate the effects of telmisartan on human esophageal cancer cell proliferation in vitro and in vivo. We assessed the effects of telmisartan on human esophageal adenocarcinoma (EAC) cells using the cell lines OE19, OE33, and SKGT-4. Telmisartan inhibited the proliferation of these three cell lines via blockade of the G0 to G1 cell cycle transition. This blockade was accompanied by a strong decrease in cyclin D1, cyclin E, and other cell cycle-related proteins. Notably, the AMP-activated protein kinase (AMPK) pathway, a fuel sensor signaling pathway, was enhanced by telmisartan. Compound C, which inhibits the two catalytic subunits of AMPK, enhanced the expression of cyclin E, leading to G0/G1 arrest in human EAC cells. In addition, telmisartan reduced the phosphorylation of epidermal growth factor receptor (p-EGFR) and ERBB2 in vitro. In our in vivo study, intraperitoneal injection of telmisartan led to a 73.2% reduction in tumor growth in mice bearing xenografts derived from OE19 cells. Furthermore, miRNA expression was significantly altered by telmisartan in vitro and in vivo. In conclusion, telmisartan suppressed human EAC cell proliferation and tumor growth by inducing cell cycle arrest via the AMPK/mTOR pathway.

Differences in miRNA expression profiles between GIST and leiomyoma in human samples acquired by submucosal tunneling biopsy

Background and study aims: Small gastrointestinal stromal tumors (GISTs) rarely have malignant potential with poor prognosis. Using conventional imaging to differentiate between small GISTs and leiomyoma, which often have similar characteristics, is difficult but essential in daily practice. Although some studies have reported on the utility of serum c-kit as a biomarker for non-small GIST and specific miRNA, clinical aspects of such testing are controversial. The aim of this study was to identify differences between small GIST and leiomyoma through the investigation of miRNA expression patterns in human cases. Patients and methods: MiRNA expression was examined in nine GIST (less than low risk, mean 18 mm in size) samples and seven leiomyoma samples acquired by a novel sampling method, submucosal tunneling biopsy (STB), which produces tumor specimens of submucosal tumor (SMT) without contamination of sufficient size to be examined under direct vision. Total RNA was extracted from these tissues and analyzed for miRNA expression patterns by microarray. Subsequently, real-time quantitative polymerase chain reaction (qPCR) were used to confirm specific miRNA overexpression, comparing GISTs with leiomyomas. Results: Microarray analysis revealed upregulation of the miR-140 family up to 20 times higher in GISTs than in leiomyomas. Real-time qPCR revealed that the expression level of miR-140-5 p in GISTs was 27.86 times higher than in leiomyomas; miR-140-3 p was 12.24 times higher as well. Conclusions: The STB method provided suitable SMT samples for miRNA analysis. MiR-140 family members may serve as specific biomarkers to distinguish GIST from leiomyoma.

Telmisartan inhibits hepatocellular carcinoma cell proliferation in vitro by inducing cell cycle arrest

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and the third leading cause of cancer-related death. Telmisartan, a widely used antihypertensive drug, is an angiotensin II type 1 (AT1) receptor blocker (ARB) that might inhibit cancer cell proliferation, but the mechanisms through which telmisartan affects various cancers remain unknown. The aim of the present study was to evaluate the effects of telmisartan on human HCC and to assess the expression of microRNAs (miRNAs). We studied the effects of telmisartan on HCC cells using the HLF, HLE, HepG2, HuH-7 and PLC/PRF/5 cell lines. In our experiments, telmisartan inhibited the proliferation of HLF, HLE and HepG2 cells, which represent poorly differentiated types of HCC cells. However, HuH-7 and PLC/PRF/5 cells, which represent well-differentiated types of HCC cells, were not sensitive to telmisartan. Telmisartan induced G0/G1 cell cycle arrest of HLF cells by inhibiting the G0-to-G1 cell cycle transition. This blockade was accompanied by a marked decrease in the levels of cyclin D1, cyclin E and other cell cycle-related proteins. Notably, the activity of the AMP-activated protein kinase (AMPK) pathway was increased, and the mammalian target of rapamycin (mTOR) pathway was inhibited by telmisartan treatment. Additionally, telmisartan increased the level of caspase-cleaved cytokeratin 18 (cCK18), partially contributed to the induction of apoptosis in HLF cells and reduced the phosphorylation of ErbB3 in HLF cells. Furthermore, miRNA expression was markedly altered by telmisartan in vitro. In conclusion, telmisartan inhibits human HCC cell proliferation by inducing cell cycle arrest.

MicroRNA profiles during galectin‑9‑induced apoptosis of pancreatic cancer cells

Pancreatic cancer is the eighth-leading cause of cancer-associated mortality in males and the ninth-leading cause in females worldwide. Even when diagnosed early enough to be potentially resectable, the prognosis of invasive pancreatic cancer is poor. Galectin-9 (Gal-9) is a tandem-repeat type galectin that has recently been demonstrated to possess an anti-proliferative effect on cancer cells. Therefore, the present study evaluated the effects of Gal-9 on the proliferation of human pancreatic cancer cells and examined the microRNAs that are associated with the antitumor effects of Gal-9. Gal-9 suppressed the proliferation of multiple pancreatic cancer cell lines. In addition, Gal-9 treatment increased the levels of caspase-cleaved keratin 18 and the expression of cytochrome c in pancreatic cancer cell lines. This data suggests that Gal-9 induces intrinsic apoptosis in pancreatic cancer cell lines through the caspase-dependent and caspase-independent pathways. In addition, Gal-9 reduced the expression levels of phosphorylated epidermal growth factor receptor and numerous receptor tyrosine kinases (RTKs). In conclusion, Gal-9 may suppress the growth of human pancreatic cancer cells in vitro. These findings suggest that Gal-9 may be a new therapeutic agent for the treatment of pancreatic cancer.

Flexible magnifying endoscopy with narrow band imaging for the diagnosis of uterine cervical tumors: A cooperative study among gastrointestinal endoscopists and gynecologists to explore a novel microvascular classification system

Narrow band imaging with magnifying endoscopy (NBI-ME), which is useful for the assessment of micro-vessels, has excellent diagnostic potential for early gastrointestinal epithelial neoplasia. Conventional diagnostic tools for uterine cervical epithelial tumors are still unsatisfactory. An accurate diagnostic tool for uterine cervical epithelial tumors is required to preserve the reproductive ability of young women with uterine cervical tumors. Flexible NBI-ME was performed in patients with cervical squamous cell lesions that required further examinations based on their Pap smear results (cytology ≥ low-grade squamous intraepithelial lesion) at Kagawa University Hospital between April 2014 and April 2015. NBI-ME results concordant with the punch biopsy sites were compared with the histological results. A retrospective review of the NBI-ME images identified abnormal NBI-ME results regarding micro-vascular patterns. All images were categorized as having abnormal features. NBI-ME revealed the following vascular pattern differences of different stage tumors: Dot-like vessels without irregular arrangements and high density in cervical intraepithelial neoplasia (CIN) CIN1-CIN2; dot-like vessels with irregular arrangements and high density in CIN3-carcinoma in situ; crawling vessels in minimum invasive cancer; and willow branch vessels and new tumor vessels in invasive cancer. NBI-ME may be an effective diagnostic tool for uterine cervical epithelial tumors, which may lead to the establishment of a novel classification system.