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The poor prognosis of hepatocellular carcinoma (HCC) has been associated with recurrence and metastasis. Recently, we established a pair of HCC cell lines from a primary (H2-P) and its matched metastatic (H2-M) HCC tumors. A high density of cDNA microarray with 9184 human cDNA was used to identify the differentially expressed genes between H2-P and H2-M. Comparing with H2-P, eight upregulated and six downregulated genes were detected in H2-M. One interesting finding is the overexpression of Vimentin (VIM), a well-defined intermediate filament, which has been linked to a more aggressive status in various tumors. The correlation of overexpression of VIM and HCC metastasis was studied by immunohistochemistry using a tissue microarray with 200 primary HCCs and 60 pairs of primary and matched metastatic HCC samples. Tissue microarray demonstrated that the overexpression of VIM was significantly associated with HCC metastasis (Po0.01). This finding strongly suggests that the overexpression of VIM may play an important role in the metastasis of HCC.

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The proteins encoded by chromosomal homologues of the parA and parB genes of many bacterial plasmids have been implicated in chromosome partitioning. Unlike their plasmid counterparts, mutant phenotypes produced by deleting these genes have so far been elusive or weakly expressed, except during sporulation. Here the properties of Pseudomonas putida strains with mutations in parA and parB are described. These mutants do not give rise to elevated levels of anucleate bacteria when grown in rich medium under standard conditions. However, in M9-minimal medium different parA and parB mutations gave between 5 and 10 % anucleate cells during the transition from exponential phase to stationary phase. Comparison of the DNA content of bacteria at different stages of the growth curve, in batch culture in L-broth and in M9-minimal medium, suggests that the par genes are particularly important for chromosome partitioning when cell division reduces the chromosome copy number per cell from two to one. This transition occurs in P. putida during the entry into stationary phase in M9-minimal medium, but not in L-broth. It is proposed that the partition apparatus is important to ensure proper chromosome segregation primarily when the bacteria are undergoing cell division in the absence of ongoing DNA replication.

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Most colorectal carcinomas (CRCs) arise from adenomas through an archetypal pathogenic pathway, the adenomacarcinoma-metastasis sequence. Aberrant expression of ␤-catenin, p16, E-cadherin and c-myc appears to have played important roles in the development and/or progression of CRC, but their precise distribution pattern and associations in different pathologic loci along CRC's pathogenic pathway have not been thoroughly examined. In this study, a tissue microarray (TMA) containing 85 advanced CRCs in different Dukes stages was constructed. In each of 85 cases, tissue specimens from normal mucosa and primary carcinomas in different layers of the bowel wall were included in the TMA. Tissue specimens from matched adenoma, lymph node metastases and distant metastases were obtained from 22, 21 and 21 cases, respectively. Expression patterns of ␤-catenin, p16, E-cadherin and c-myc were evaluated by immunohistochemistry. The results revealed that nuclear expression of ␤-catenin, p16 and c-myc was quantitatively increased from normal mucosa to premalignant adenoma, primary carcinoma and lymph node metastatic carcinoma; the frequency of nuclear overexpression of ␤-catenin and p16 in lymph node metastases was significantly higher than that in distant metastases (p < 0.05). These results suggest an association between nuclear overexpression of ␤-catenin and/or p16 and CRC lymph node metastasis but not distant metastasis. The results also showed that correlative high nuclear expression of ␤-catenin and c-myc was observed in primary carcinomas involving the serosa and lymph node metastases (p < 0.05) but not in other pathologic regions of CRCs, suggesting that the tumor microenvironment in different pathologic loci of colorectal tumorigenesis and progression may influence cmyc responsiveness to ␤-catenin/Tcf activation. © 2003 Wiley-Liss, Inc. Key words: colorectal carcinoma; heterogeneity; immunohistochemistry; fluorescence in situ hybridizationColorectal carcinoma (CRC) is one of the most common malignancies and a major cause of cancer death in the developed countries. 1 The incidence of CRC varies greatly around the world, with the highest incidence in the Western world and the lowest in India. 2 In urban Shanghai, China, the incidence of CRC increased rapidly and doubled over a 23-year period (1972-1994). 3 It is now widely accepted that most CRCs arise from adenomas through a process described as the adenoma-carcinoma-metastasis sequence. Tumorigenesis and progression of CRC is believed to be influenced by the genetic accumulation of abnormalities of numerous tumor suppressor genes and oncogenes, including nuclear overexpression of ␤-catenin, p16 and c-myc and loss expression of membranous E-cadherin. 4 -8 However, it is well known that the distribution pattern of gene expression detected by immunohistochemistry in tumor tissue, especially in certain histologically and genetically heterogeneous tumors, is often substantially varied. Germane to the present study, previous studies have documented heterogeneous expression ...

Mesangial cell (MC) phenotypic transition is crucial for the progression of diabetic nephropathy. A major stimulus mediating high glucose-induced MC phenotypic transition is TGF-β1. Our current study focuses on microRNA-215 (miR-215) and investigates its role in TGF-β1-mediated MC phenotypic transition. Using real-time quantitative PCR (qRT-PCR) and northern blotting, we determined that the miR-192/215 family is dramatically upregulated under diabetic conditions both in vitro and in vivo. Gain- and loss-of-function approaches demonstrated that miR-215 inhibition significantly inhibited TGF-β1-induced mouse mesangial cell (MMC) phenotypic transition, whereas miR-215 upregulation promoted MMC phenotypic transition. Interestingly, these changes were not detected in cells that were treated with TGF-β1 and miR-192 mimics or inhibitors. These results suggest that miR-215 participates in TGF-β1-induced MMC phenotypic transition. Luciferase reporter assays were used to identify whether catenin-beta interacting protein 1 (CTNNBIP1) is a direct target of miR-215, which was predicted by bioinformatic analysis. Mechanistic studies revealed that CTNNBIP1 suppresses Wnt/β-catenin signaling and that miR-215 promotes β-catenin activation and upregulates α-SMA and fibronectin expression in TGF-β1-treated MMCs by targeting CTNNBIP1. In addition, in vivo miR-215 silencing with a specific antagomir significantly increased CTNNBIP1 protein expression, resulting in reduced β-catenin activity and decreased α-SMA and fibronectin expression in db/db mouse kidney glomeruli. Taken together, our findings indicate that miR-215 plays an essential role in MC phenotypic transition by regulating the CTNNBIP1/β-catenin pathway, which is related to the pathogenesis of diabetic nephropathy.

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