No abstract

Cancer is believed to arise primarily through accumulation of genetic mutations. Although induced pluripotent stem cell (iPSC) generation does not require changes in genomic sequence, iPSCs acquire unlimited growth potential, a characteristic shared with cancer cells. Here, we describe a murine system in which reprogramming factor expression in vivo can be controlled temporally with doxycycline (Dox). Notably, transient expression of reprogramming factors in vivo results in tumor development in various tissues consisting of undifferentiated dysplastic cells exhibiting global changes in DNA methylation patterns. The Dox-withdrawn tumors arising in the kidney share a number of characteristics with Wilms tumor, a common pediatric kidney cancer. We also demonstrate that iPSCs derived from Dox-withdrawn kidney tumor cells give rise to nonneoplastic kidney cells in mice, proving that they have not undergone irreversible genetic transformation. These findings suggest that epigenetic regulation associated with iPSC derivation may drive development of particular types of cancer.

Purpose: (À)-Epigallocatechin gallate (EGCG) inhibits activation of the epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor-2 (HER2) and multiple downstream signaling pathways in cancer cell lines. In this study we compared the cellular and molecular effects of EGCG with a well-standardized decaffeinated green tea catechin mixture Polyphenon E (Poly E) on human colon cancer cell lines. Experimental Design and Results: Both EGCG and Poly E preferentially inhibited growth of the Caco2, HCT116, HT29, SW480, and SW837 colon cancer cells when compared with the FHC normal human fetal colon cell line. The EGFR and HER2 proteins were overexpressed and constitutively activated in all of the colon cancer cell lines when compared with the FHC cell line. Treatment of HT29 cells with EGCG or Poly E caused an increase of cells in G 1 and induced apoptosis. Both EGCG and Poly E caused a decrease in the phosphorylated forms of EGFR and HER2 proteins, and subsequently caused a decrease in the phosphorylated forms of the extracellular signal-regulated kinase and Akt proteins. Similar effects of these compounds were seen when the cells were stimulated with transforming growth factor a. Reporter assays indicated that both EGCG and Poly E inhibited the transcriptional activity of the activator protein 1 (AP-1), c-fos, nuclear factor nB, and cyclin D1promoters.The combination of only 1 Mg/mL of epicatechin plus 10 Mg/mL of EGCG displayed synergistic effects on growth inhibition and induction of apoptosis. Furthermore, when treatment was prolonged for 96 hours, 1 Mg/mL of EGCG or Poly E was sufficient to inhibit growth, reduce activation of EGFR and HER2, and induce apoptosis. Conclusion: Our findings suggest that EGCG or Poly E may be useful in the chemoprevention and/or treatment of colon cancer. Poly E contains about 60% EGCG, yet pure EGCG and Poly E had similar potencies (expressed as Mg/mL). Poly E may be preferable because it is easier to prepare and this mixture of catechins may exert synergistic effects.

Skeletal muscle depletion is an independent prognostic factor. Intervention to prevent muscle wasting might be an effective strategy for improving the outcome of HCC.

Background We previously reported that the incidence of hepatocellular carcinoma (HCC) with non-viral etiologies increased rapidly between 1991 and 2010 in Japan. Methods To update this investigation, we enrolled patients who were initially diagnosed as having non-B, non-C HCC at participating hospitals between 2011 and 2015. In addition to the patient characteristics investigated in the previous report, we also investigated the duration of alcohol consumption. The overall survival rate was analyzed using the Kaplan–Meier method, and the hazard function against the body mass index (BMI) was plotted using cubic splines. Results A total of 2087 patients were enrolled. The proportion of patients with non-viral etiologies has continued to increase from 10.0% in 1991 to 32.5% in 2015. Patients were also older (median ages, 70–73 years) and more obese (median BMIs, 23.9–24.2 kg/m 2 ), and the proportions of patients with diabetes mellitus (46.1% to 51.6%), hypertension (42.7% to 58.6%), dyslipidemia (14.6% to 22.9%), and fatty liver (24.0% to 28.8%) had all increased significantly. There was a significant inverse relationship between the duration and the amount of daily alcohol consumption. The improvement in the overall survival was relatively small, with a decreased proportion of patients under surveillance (41.3% to 31.6%). A hazard function plot showed a curve similar to that in our previous report, with a lowest hazard of ~ 26 kg/m 2 . Conclusions The proportion of HCC patients with non-viral etiologies continues to increase in Japan. Lifetime total amount of alcohol consumption may be a risk factor. Electronic supplementary material The online version of this article (10.1007/s00535-018-1532-5) contains supplementary material, which is available to authorized users.