Search

Cholangiocarcinoma is the most common biliary duct malignancy and the second most common primary liver cancer, accounting for 10‑20% of hepatic malignancies. With high mortality and poor prognosis, the 5‑year survival rate of cholangiocarcinoma is only 10%. A previous study demonstrated a significant association between aspirin use and a decreased risk of cholangiocarcinoma. However, the effect of aspirin on cholangiocarcinoma remains unknown. Therefore, the aim of the present study was to investigate the effects of aspirin on cholangiocarcinoma in vitro and in vivo. Three cholangiocarcinoma cell lines were used to analyze the effect of aspirin on cell proliferation, cell cycle progression, apoptosis, and the regulation of microRNAs. MicroRNAs are known to regulate the development and progression of various types of cancer. An HuCCT‑1 xenograft model was used for the in vivo study. It was determined that aspirin inhibited the proliferation of human cholangiocarcinoma cells (except TKKK cells). Aspirin induced cell cycle arrest in the G0/G1 phase and regulated cell‑cycle related proteins in cholangiocarcinoma cells (HuCCT‑1 cells) but did not induce apoptosis. The expression of miR‑340‑5p was significantly upregulated after treatment, and overexpression of miR‑340‑5p inhibited the proliferation of HuCCT‑1 cells and decreased the levels of cyclin D1. TKKK cells had low miR‑340‑5p expression, which may explain why aspirin had no effect on their proliferation. In vivo, aspirin reduced the growth of xenografted tumors. In conclusion, the present study indicated that aspirin partially inhibited cholangiocarcinoma cell proliferation and tumor growth by inducing G0/G1 phase cell cycle arrest, potentially through the miR‑340‑5p/cyclin D1 axis.

Recent studies have reported that immune checkpoint inhibitors are effective against various defective mismatch repair (dMMR)/microsatellite instability-high (MSI-H) cancers. A limited number of reports are available on the frequency of dMMR/MSI-H carcinoma in biliary tract cancer (BTC), describing its clinicopathological characteristics and prognosis. The latter carcinoma is also associated with Lynch syndrome (LS). The present study was performed to investigate the frequency of patients with dMMR/MSI-H in BTC and the clinical characteristics of BTC with dMMR/MSI-H in a single institution in Japan. A total of 116 patients with BTC who underwent curative surgical resection at Kagawa University Hospital between January 2008 and December 2017 were included. The protein expression levels of the mismatch repair (MMR) genes [mutL homolog 1 (MLH1), mismatch repair endonuclease PMS2 (PMS2), MutS homolog (MSH)2 and MSH6] were assessed by immunohistochemistry (IHC) using formalin-fixed paraffin-embedded tissue specimens. Subsequently, MSI testing was performed on patients who exhibited loss of MMR protein expression. Loss of expression of one or more proteins was detected in five cases (4.3%). Loss of MLH1/PMS2 expression was observed in one case of intrahepatic cholangiocarcinoma, whereas loss of PMS2 expression was noted in one case of perihilar cholangiocarcinoma. Loss of MSH2/MSH6 and MSH6 expression was noted in two cases of distal cholangiocarcinoma and loss of PMS2 expression in one case of ampullary carcinoma. Out of the five patients, two demonstrated MSI-H. Microsatellite stability was observed in two cases and for one case, no data were available. Two MSI-H cases were patients with loss of expression of MLH1/PMS2 and MSH2/MSH6. None of the five patients exhibited a past medical history or family history of suspected LS. The frequency of dMMR in BTC was ~5%, which was similar to that reported by similar studies performed in other countries. In the present study, IHC appeared to be more useful than MSI testing for detecting MMR abnormalities with regards to the detection rate. Furthermore, there may only be a limited number of patients with BTCs who are likely to benefit from the therapeutic effects of treatment with immune checkpoint inhibitors.

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.

Visceral adipose tissue contributes to the pathophysiology of metabolic syndrome. Metformin has been reported to suppress lipogenesis in a murine preadipocyte cell line. However, the effect of metformin on the differentiation of human visceral adipose tissue remains unknown. MicroRNAs (miRNAs or miRs) have been suggested as therapeutic targets because of their involvement in the differentiation and maturation of fatty cells. The aim of this study was to determine whether metformin suppresses the differentiation of human preadipocytes and to identify miRNAs associated with the regulation of lipid metabolism. Human visceral preadipocytes (HPrAD-vis) were preincubated in growth media and then cultured with differentiation media containing metformin for 1 or 2 weeks. Adipogenic differentiation of the cells was assessed by Oil Red O staining, and soluble adiponectin in the culture media was measured using an enzyme-linked immunosorbent assay. Cell proliferation was assessed using a WST-8 assay, and the gene and protein expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT‑enhancer-binding protein α (C/EBPα) was determined by RT-qPCR and western blot analysis, respectively. miRNAs were profiled using human miRNA Oligo chips after total RNA was extracted and labeled. Oil Red O staining showed that metformin suppressed the accumulation of lipid droplets in HPrAD-vis cells. The adiponectin concentration in the culture media was also decreased in metformin-treated cells. The WST-8 assay revealed no effect on proliferation or growth inhibition following metformin treatment, although metformin suppressed the expression of PPARγ and C/EBPα. miRNA profiling further revealed differences between the metformin-treated group and control HPrAD-vis cells. Thus, the findings of the present study demonstrated that metformin suppressed the differentiation of human preadipocytes in vitro and altered the miRNA profile of these cells. Thus, the miRNAs whose expression levels were altered by metformin may contribute to the observed suppression of HPrAD-vis cell differentiation.

Linitis plastica is a gastric cancer of diffuse histotype that presents in the fundic gland area, and is characterized by thickening of the stomach wall and deformation of the stomach, resulting in a leather bottle-like appearance. A 66-year-old female was admitted to Kagawa University Hospital (Kagawa, Japan) with epigastric pain. X-ray examination revealed reduced gastric distension and deformation of the stomach, which exhibited a leather bottle-like appearance. Endoscopy indicated a depressed lesion in the gastric antrum, and abnormal folds, which crossed to form a waffle-like appearance in the upper gastric body. Analysis of biopsy specimens from the depressed lesion revealed a poorly differentiated adenocarcinoma. Morphological changes in the gastric folds indicated that the tumor had invaded the upper gastric body, therefore, a total gastrectomy was performed. Subsequent pathological findings demonstrated that the tumor had spread from the primary lesion to the upper gastric body. Therefore, the present report recommends that the diagnosis of the spread of linitis plastica-type gastric cancer should include assessments of the primary lesion, as well as evaluation of morphological changes in the gastric folds.

Percutaneous radiofrequency ablation (RFA) enables cauterization of liver cancer in a limited number of sessions without major complications. In contrast to the efficacy of this technique, the size of coagulation necrosis is limited due to increased impedance. D-sorbitol has been used as an irrigating fluid during transurethral resection of the prostate, since it is considered to be a dielectric fluid. In order to determine whether D-sorbitol enhances the effect of RFA, RFA was performed by slowly injecting 3% D-sorbitol near the tip of the RFA needle. The maximum of the total injected volume of D-sorbitol was 20 ml and RFA was terminated if the threshold of impedance was exceeded. RFA and D-sorbitol RFA were performed in 5 different parts of pig livers and dog livers in vivo. The total volumes of coagulation necrosis in the D-sorbitol RFA group were significantly higher compared with those in the RFA group. The total delivered energy in the D-sorbitol RFA group was also higher compared with that in the RFA group, due to the suppression of impedance elevation. No significant complications, such as bleeding or damage, were observed during the D-sorbitol RFA procedure in the in vivo model. In conclusion, RFA combined with D-sorbitol increases the total volume of coagulation necrosis through controlling impedance in the ablated liver and, therefore, D-sorbitol may be useful for the treatment of liver cancers.