There is a significant positive correlation between median velocity measured by using ARFI sonoelastography and severity of liver fibrosis in patients with NAFLD. The results of ARFI sonoelastography were similar to those of transient sonoelastography.

No abstract

The biguanide metformin is widely used for treating diabetes mellitus. We previously showed the chemopreventive effect of metformin in two rodent models of colorectal carcinogenesis. However, besides epidemiologic studies, little is known about the effects of metformin on human colorectal carcinogenesis. The objective of this pilot study was to evaluate the chemopreventive effect of metformin on rectal aberrant crypt foci (ACF), which are an endoscopic surrogate marker of colorectal cancer. We prospectively randomized 26 nondiabetic patients with ACF to treatment with metformin (250 mg/d, n = 12) or no treatment (control, n = 14); 23 patients were evaluable for end point analyses (9 metformin and 14 control); the two groups were similar in ACF number and other baseline clinical characteristics. Magnifying colonoscopy determined the number of rectal ACF in each patient at baseline and after 1 month in a blinded fashion (as were all laboratory end point analyses). We also examined proliferative activity in colonic epithelium (via proliferating cell nuclear antigen labeling index) and apoptotic activity (via terminal deoxynucleotidyl transferase dUTP nick-end labeling). At 1 month, the metformin group had a significant decrease in the mean number of ACF per patient (8.78 ± 6.45 before treatment versus 5.11 ± 4.99 at 1 month, P = 0.007), whereas the mean ACF number did not change significantly in the control group (7.23 ± 6.65 versus 7.56 ± 6.75, P = 0.609). The proliferating cell nuclear antigen index was significantly decreased and the apoptotic cell index remained unaltered in normal rectal epithelium in metformin patients. This first reported trial of metformin for inhibiting colorectal carcinogenesis in humans provides preliminary evidence that metformin suppresses colonic epithelial proliferation and rectal ACF formation in humans, suggesting its promise for the chemoprevention of colorectal cancer. Cancer Prev Res; 3(9);

Metformin is widely used for the treatment of diabetes mellitus. Adenosine monophosphate-activated protein kinase (AMPK) is known to be activated by metformin and to inhibit the mammalian target of rapamycin (mTOR) pathway. The mTOR pathway plays an important role in the protein translational machinery and cell proliferation. We examined the effect of metformin on the suppression of colorectal carcinogenesis in chemical carcinogen-induced models. Seven-wk-old BALB/c mice were intraperitoneally (i.p.) injected with azoxymethane (AOM, 10 mg/kg) and then treated with or without metformin (250 mg/kg/d) for 6 wk (for the investigation of aberrant crypt foci [ACF] formation) or 32 wk (for polyp formation). We next investigated colonic epithelial proliferation using bromodeoxyuridine (BrdU) and the proliferating cell nuclear antigen (PCNA) labeling indices. Furthermore, to examine the indirect effect of metformin, the insulin resistance status and the serum lipid levels were assessed. Treatment with metformin significantly reduced ACF formation. The effect of metformin on colon polyp inhibition was relatively modest. No significant difference in body weight or glucose concentration was observed. The BrdU and PCNA indices decreased in mice treated with metformin. A Western blot analysis revealed that the phosphorylated mTOR, S6 kinase, and S6 protein levels in the colonic mucosa decreased significantly in mice treated with metformin. In conclusion, metformin suppresses colonic epithelial proliferation via the inhibition of the mTOR pathway through the activation of AMPK. As metformin is already used daily as an antidiabetic drug, it might be a safe and promising candidate for the chemoprevention of colorectal cancer.

Metformin is a biguanide derivative that is widely used in the treatment of diabetes mellitus. One of the pharmacological targets of metformin is adenosine monophosphate-activated protein kinase (AMPK). We investigated the effect of metformin on the suppression of intestinal polyp formation in Apc