MicroRNAs: regulators of cancer metastasis and epithelial-mesenchymal transition (EMT).

Tumor metastasis is the main cause of death in patients with solid tumors. The epithelial-mesenchymal transition (EMT) process, in which epithelial cells are converted into mesenchymal cells, is frequently activated during cancer invasion and metastasis. MicroRNAs (miRNAs) are small, non-coding RNAs that provide widespread expressional control by repressing mRNA translation and inducing mRNA degradation. The fundamental roles of miRNAs in tumor growth and metastasis have been increasingly well recognized. A growing number of miRNAs are reported to regulate tumor invasion/metastasis through EMT-related and/or non-EMT- related mechanisms. In this review, we discuss the functional role and molecular mechanism of miRNAs in regulating cancer metastasis and EMT.

A Potential Model for Detecting Crowding-induced Epithelial Cell and Cancer Cell Extrusion.

Overcrowding and cell deformation lead to the shedding of apoptotic and live cells to maintain homeostasis in the epithelium. Recent studies have attempted to explain the effect of extrusion on epithelial homeostasis and tumor metastasis, but lack the requisite quantitative models for testing extrusion. Here, we designed a petri dish inversion model to detect the extrusion ability of both normal epithelial cells and epithelial cancer cells. Firstly, we found cell extrusion was observed in both normal epithelial cells (LO2 cells) and cancer cells; in confluent LO2 cell culture, certain cells were surrounded by their neighbors, suffered "collective attack", and were then made round in shape. Green fluorescent protein (GFP)-labeled cancer cells were also found to be squeezed by normal LO2 cells. Using the petri dish inversion model, we quantified the number of extrusion cells, and demonstrated that the ability of cancer cell extrusion was related to the metastatic potential of cancer cell lines. Our findings provide a novel model to detect crowding-induced epithelial cell and cancer cell extrusion. This novel model provides a quantitative method for research into apoptotic and cancer cell extrusion, particularly in human hepatocellular carcinoma.

Crystallization and preliminary crystallographic studies of human septin 1 with site-directed mutations.

Septin 1 is a member of an evolutionarily conserved family of GTP-binding and filament-forming proteins named septins, which function in diverse processes including cytokinasis, vesicle trafficking, apoptosis, remodelling of the cytoskeleton, infection, neurodegeneration and neoplasia. Human septin 1 has been expressed and purified, but suffers from severe aggregation. Studies have shown that septin 1 with site-directed mutations of five serine residues (Ser19, Ser206, Ser307, Ser312 and Ser315) has a much lower degree of aggregation and better structural homogeneity and that the mutations cause only slight perturbations in the secondary structure of septin 1. This septin 1 mutant was crystallized and diffraction data were collected to 2.5 A resolution. The space group is P422, with unit-cell parameters a = b = 106.028, c = 137.852 A.

Comparison of laparoscopic vs open liver lobectomy (segmentectomy) for hepatocellular carcinoma.

AIM: To investigate the effects of laparoscopic hepatectomy for the treatment of hepatocellular carcinoma (HCC). METHODS: From 2006 to January 2011, laparoscopic hepatectomies were performed on 30 cases of HCC at Northern Jiangsu People's Hospital. During this same time period, 30 patients elected to undergo conventional open hepatectomy over laparoscopic hepatectomy at the time of informed consent. The degree of invasiveness and outcomes of laparoscopic hepatectomy compared to open hepatectomy for HCC were evaluated. RESULTS: Both groups presented with similar blood loss amounts, operating times and complications. Patients in the laparoscopic hepatectomy group started walking and eating significantly earlier than those in the open hepatectomy group, and these more rapid recoveries allowed for shorter hospitalizations. There were no significant differences between procedures in survival rate. CONCLUSION: Laparoscopic hepatectomy is beneficial for patient quality of life if the indications are appropriately based on preoperative liver function and the location and size of the HCC.