High expression level and nuclear localization of Sam68 are associated with progression and poor prognosis in colorectal cancer.

BACKGROUND: Src-associated in mitosis (Sam68; 68 kDa) has been implicated in the oncogenesis and progression of several human cancers. The aim of this study was to investigate the clinicopathologic significance of Sam68 expression and its subcellular localization in colorectal cancer (CRC). METHODS: Sam68 expression was examined in CRC cell lines, nine matched CRC tissues and adjacent noncancerous tissues using reverse transcription (RT)-PCR, quantitative RT-PCR and Western blotting. Sam68 protein expression and localization were determined in 224 paraffin-embedded archived CRC samples using immunohistochemistry. Statistical analyses were applied to evaluate the clinicopathologic significance. RESULTS: Sam68 was upregulated in CRC cell lines and CRC, as compared with normal tissues; high Sam68 expression was detected in 120/224 (53.6%) of the CRC tissues. High Sam68 expression correlated significantly with poor differentiation (P = 0.033), advanced T stage (P < 0.001), N stage (P = 0.023) and distant metastasis (P = 0.033). Sam68 nuclear localization correlated significantly with poor differentiation (P = 0.002) and T stage (P =0.021). Patients with high Sam68 expression or Sam68 nuclear localization had poorer overall survival than patients with low Sam68 expression or Sam68 cytoplasmic localization. Patients with high Sam68 expression had a higher risk of recurrence than those with low Sam68 expression. CONCLUSIONS: Overexpression of Sam68 correlated highly with cancer progression and poor differentiation in CRC. High Sam68 expression and Sam68 nuclear localization were associated with poorer overall survival.

microRNA-224 promotes cell proliferation and tumor growth in human colorectal cancer by repressing PHLPP1 and PHLPP2.

PURPOSE: To investigate the clinicopathologic significance, role, and mechanism of action of microRNA-224 (miR-224) in colorectal cancer. EXPERIMENTAL DESIGN: Real-time PCR was used to quantify miR-224 expression. The association of miR-224 with the clinicopathologic features and survival was evaluated in 110 colorectal cancer patients. The role of miR-224 in colorectal cancer was investigated using in vitro and in vivo assays. Luciferase reporter assays were conducted to confirm target gene associations. RESULTS: miR-224 was overexpressed in colorectal cancer. High-level expression of miR-224 was significantly associated with an aggressive phenotype and poor prognosis. Overexpression of miR-224 promoted colorectal cancer cell proliferation in vitro and tumor growth in vivo. Specifically, miR-224 accelerated the G1-S phase transition through activation of AKT/FOXO3a signaling, downregulation of p21Cip1 and p27Kip1, and upregulation of cyclin D1. Moreover, both PH domain leucine-rich-repeats protein phosphatase 1 (PHLPP1) and PHLPP2, antagonists of PI3K/AKT signaling, were confirmed as bona fide targets of miR-224. miR-224 directly targeted the 3'-untranslated regions of the PHLPP1 and PHLPP2 mRNAs and repressed their expression. CONCLUSION: This study reveals functional and mechanistic links between miRNA-224 and the tumor suppressors PHLPP1 and PHLPP2 in the pathogenesis of colorectal cancer. miR-224 not only plays important roles in the regulation of cell proliferation and tumor growth in colorectal cancer, but also has potential as a prognostic marker or therapeutic target for colorectal cancer.

Effects of two Lactobacillus strains on lipid metabolism and intestinal microflora in rats fed a high-cholesterol diet.

BACKGROUND: The hypocholesterolemic effects of lactic acid bacteria (LAB) have now become an area of great interest and controversy for many scientists. In this study, we evaluated the effects of Lactobacillus plantarum 9-41-A and Lactobacillus fermentum M1-16 on body weight, lipid metabolism and intestinal microflora of rats fed a high-cholesterol diet. METHODS: Forty rats were assigned to four groups and fed either a normal or a high-cholesterol diet. The LAB-treated groups received the high-cholesterol diet supplemented with Lactobacillus plantarum 9-41-A or Lactobacillus fermentum M1-16. The rats were sacrificed after a 6-week feeding period. Body weights, visceral organ and fat pad weights, serum and liver cholesterol and lipid levels, and fecal cholesterol and bile acid concentrations were measured. Liver lipid deposition and adipocyte size were evaluated histologically. RESULTS: Compared with rats fed a high-cholesterol diet but without LAB supplementation, serum total cholesterol, low-density lipoprotein cholesterol and triglycerides levels were significantly decreased in LAB-treated rats (p < 0.05), with no significant change in high-density lipoprotein cholesterol levels. Hepatic cholesterol and triglyceride levels and liver lipid deposition were significantly decreased in the LAB-treated groups (p < 0.05). Accordingly, both fecal cholesterol and bile acids levels were significantly increased after LAB administration (p < 0.05). Intestinal Lactobacillus and Bifidobacterium colonies were increased while Escherichia coli colonies were decreased in the LAB-treated groups. Fecal water content was higher in the LAB-treated groups. Compared with rats fed a high-cholesterol diet, administration of Lactobacillus plantarum 9-41-A resulted in decreases in the body weight gain, liver and fat pad weight, and adipocytes size (p < 0.05). CONCLUSIONS: This study suggests that LAB supplementation has hypocholesterolemic effects in rats fed a high-cholesterol diet. The ability to lower serum cholesterol varies among LAB strains. Our strains might be able to improve the intestinal microbial balance and potentially improve intestinal transit time. Although the mechanism is largely unknown, L. plantarum 9-41-A may play a role in fat metabolism.

[Analysis of clinical characteristics of 43 surgical patients with Crohn disease using the Montreal classification].

OBJECTIVE: To investigate the clinical features of Crohn disease according to the Montreal classification. METHODS: Clinical data of 43 surgical patients with Crohn disease (surgical group) and 125 non-surgical patients with Crohn disease (non-surgical group) were retrospectively analyzed and compared between two groups. The Montreal classification was used. RESULTS: In the surgical group, 28 patients (65.1%) were A2, 14 (32.6%) were A3 and only one was A1, which was not significantly different as compared to the non-surgery group. The proportions of L1, L2, L3, and L4 subtype in the surgical group were 41.9%, 25.6%, 30.2%, and 2.3%, respectively, which was not significantly different as compared to that in the non-surgery group. In the surgical group,B1 disease was found in 1 case (2.3%), B2 in 26 cases (60.5%), and B3 in 16 cases (37.2%), while in the non-surgical group, B1 was found in 79 cases (63.2%), B2 in 44 cases (35.2%) and B3 in 2 cases (1.6%). Differences were significant between two groups in disease behavior (P=0.001, P=0.004, P=0.001). CONCLUSIONS: Most surgical patients of Crohn disease are A2. L1 and L3 are the main lesion location. As disease behavior, B2 and B3 are the main reasons for operation.