We found that: 1) a significant number of patients with APA had somatic mutations of the KCNJ5 gene; 2) KCNJ5 mRNA levels were higher in the APA with KCNJ5 mutations; and 3) the expression of KCNJ5 mRNA was significantly higher in APA than cortisol-producing adenomas and pheochromocytomas.

Nuclear magnetic resonance spectroscopy has detected elevated phosphocholine levels in human tumor tissues and cells, and in cells that were transformed with the activated Ha-ras gene and stimulated in vitro with growth-promoting factors such as platelet-derived growth factor, epidermal growth factor, and phorbol ester. However, the mechanism of the elevation and the function of the increased phosphocholine levels have not been clearly demonstrated. We studied phosphocholine levels enzymatically and analyzed the activity of choline kinase, which catalyzes the phosphorylation of choline to produce phosphocholine, in human colon cancer and adenoma. Both choline kinase activity and phosphocholine levels were increased in colon cancer and adenoma tissue. The activation of choline kinase and the increased levels of choline kinase α α α α were partly responsible for the elevated phosphocholine levels. This study suggests that choline kinase might play a role in growth promotion or signal transduction in carcinogenesis.Key words: Choline kinase -Phosphocholine -Human colon cancerCancer of the colon is one of the most common cancers in developed countries and its prevention is of great interest throughout the world. It is thought that the accumulation of certain mutated genes, including oncogenes, tumor suppressor genes, genes for DNA-repair enzymes, and invasion/metastasis-related genes, is necessary for the onset and progression of cancer. Mutation may cause further malignant changes in cellular proliferation, especially in enzymatic properties and activity.1-3) Some of the changes in enzymatic properties and activity with proliferation may be advantageous to the cancer cells. [4][5][6][7] Studying the cellular properties of cancer cells improves our understanding of the mechanism of cellular growth control and sheds further light on cancer prevention and treatment. 8) Choline kinase is the first enzyme in the cytidine 5′-diphosphate (CDP)-choline pathway for the synthesis of phosphatidylcholine, and phosphorylates choline to phosphocholine using adenosine 5′-triphosphate (ATP) as the phosphate donor. [9][10][11] In vitro studies of oncogenic ras proteins, and products and growth factors have shown that phosphocholine contributes to cellular growth regulation and intracellular signal transduction. Ras proteins play a pivotal role in cellular signal transduction, and help regulate cellular proliferation and terminal differentiation. [12][13][14] Microinjecting the oncogenic Ha-ras gene product p21 ras into Xenopus oocytes causes meiosis, 15) quickly activates choline kinase and elevates phosphocholine levels. 16)Transforming fibroblastic cells with oncogenic Ha-ras also activates choline kinase. [17][18][19] Growth factors essential for cellular growth also activate choline kinase, elevating the intracellular phosphocholine level. Prolactin is one such growth factor for Nb 2 rat node lymphoma cells.20) It has been suggested that platelet-derived growth factor might use a choline kinase-phosphocholine route to promote c...

FR167653 administration decreased serum TNF-alpha and IL-1beta concentrations, which was associated with decreased lung injury and lethality. The mechanism responsible for the decreased TNF-alpha and IL-1 may be related to the inhibitory effect of FR167653 on p38 MAP kinase activation.

We have shown that angiotensin II (Ang II)-induced hypertrophy of vascular smooth muscle cells is dependent on the balance between proliferatlve and antlproliferative growth factors, specifically basic fibroblast growth factor and transforming growth factor-/31 (TGF-01), respectively. We now present evidence, based on two phenotypically distinct cell cultures, that the ability to secrete the biologically active form of TGF-/31 is central to the growth response to Ang II. Two separate cultures were examined, one in which Ang II induces hypertrophy and the other in which Ang II induces hyperplasia. Ang II induces the expression of basic fibroblast growth factor twofold to fivefold in both cultures. Furthermore, both cultures express TGF-/J1. In the culture that responds with hypertrophy, Ang II induces the expression of the active form of TGF-/31 twofold to threefold. However, in the culture that responds with hyperplasia, no active TGF-/J1 was detected either at baseline or after Ang II exposure. Interestingly, all the TGF-01 present was in the inactive, latent form. In the culture that responded with hyperplasia, Ang II induced a fourfold to fivefold increase in DNA synthesis. This increase could be abolished by the addition of active TGF-01. Thus in these two cultures the ability to activate TGF-01 dictates the cellular response to Ang II. These results support our hypothesis that a balance of proliferative and antiproliferative autocrine signals mediates the growth control of vascular smooth muscle cells. 1 For example, hypertension results in vascular hypertrophy that in large conduit vessels, is due primarily to cellular hypertrophy, 2 whereas in resistance arteries hyperplasia predominates.3 In atherosclerosis, vascular smooth muscle proliferation within the intima is a major cause of plaque formation.1 Moreover, the vascular response to injury after mechanical trauma such as balloon angioplasty 4 also involves smooth muscle proliferation. The understanding of the mechanisms behind abnormal, uncontrolled proliferation is central to attempts to inhibit or control lesion formation.Among the factors responsible for the regulation of vascular smooth muscle growth, vasoactive substances play a major role. Angiotensin II (Ang II) has been used as a paradigm for these studies. In vivo, angiotensin converting enzyme (ACE) inhibitors attenuate the development of hypertension-induced vascular hypertro-

Cancer cells acquire particular characteristics that benefit their proliferation. We previously reported that human colon cancers examined had increased choline kinase activity and phosphocholine levels. The elevated phosphocholine levels were in part due to both activation of choline kinase and increased choline kinase α α α α protein levels. In this report, we analyzed choline kinase, which catalyzes the phosphorylation of choline to produce phosphocholine, in rat 1,2-dimethylhydrazine (DMH)-induced colon cancer. This study is the first to demonstrate increased choline kinase α α α α enzymatic activity, protein levels, and mRNA levels in DMH-induced colon cancer as well as human colon cancer, although phosphocholine was not increased in DMH-induced rat cancer. The increase in the mRNA level was partly due to an increase in the transcription of the choline kinase α α α α gene. The increased choline kinase activity may be a specific characteristic acquired by cancer cells that benefits their proliferation. Key words: Choline kinase -DMH -CancerCancer of the colon is one of the most common cancers in developed countries and its prevention is of great interest throughout the world. It is thought that an accumulation of mutated genes, including oncogenes, tumor suppressor genes, DNA-repair enzyme genes, and invasion/ metastasis-related genes, is necessary for the generation and progression of cancer. Mutation may cause further malignant changes in cellular proliferation, 1) especially when enzymatic activity and properties are affected. 2-4)Some of the changes that occur in enzymatic properties and activity with proliferation may favor the growth of cancer cells. [5][6][7] Studying the cellular properties of cancer cells furthers our understanding of the mechanisms of cellular growth control and provides clues to strategies for cancer prevention and treatment. 8) 1,2-Dimethylhydrazine (DMH) is widely used for experimental studies of specific colon carcinogenesis in rodents. 9) In the body, the metabolic product of DMH modifies DNA, causes mutation, and leads to carcinogenesis. 10)Choline kinase is the first enzyme in the CDP-choline pathway for the synthesis of phosphatidylcholine, and phosphorylates choline to phosphocholine using adenosine 5′-triphosphate (ATP) as the phosphate donor.11, 12) Ras proteins play a pivotal role in cellular signal transduction, and help regulate cellular proliferation and terminal differentiation. [13][14][15] Microinjection of the oncogenic Ha-ras gene product p21 ras into Xenopus oocytes, which causes meiosis, 16) quickly elevates the phosphocholine level and activates choline kinase.17) Transformation of fibroblastic cells with oncogenic Ha-ras activates choline kinase. [18][19][20] Growth factors essential for cellular growth also activate choline kinase, elevating the intracellular phosphocholine level. It has been suggested that platelet-derived growth factor might use a choline kinase-phosphocholine route to promote cell growth in NIH3T3 fibroblast cells. [21][22][23][24] We pr...

No abstract

Estrogen is a key regulator of the proliferation and differentiation of breast cancer cells. In addition to the estrogen supply from the ovary, estrogen is produced locally from androgen by aromatase. However, the regulation of aromatase gene expression in breast cancer has not yet been fully clarified. Retinoic acid receptor-related orphan receptor (ROR) ␣ plays an important role in the differentiation of many organs by regulating the transcription of target genes. Because aromatase and ROR␣ are expressed in breast cancer, the effect of ROR␣ on aromatase gene expression was studied. ROR␣ significantly augmented the expression of aromatase mRNA, particularly those containing exon I.4, in MCF7 cells, and aromatase activities in T47D and MCF7 cells. ROR␣ also stimulated the proliferation of these cells. Transient transfection-based reporter gene assays using the promoter at exon I.4 showed that ROR␣ augmented the transcription. A series of truncated mutation studies revealed that ROR␣ activated the transcription through ؊147 to ؉14 bp of the promoter I.4. Furthermore, ROR␣ bound to the fragment containing ؊119 to ؊107 bp of the promoter in vitro, indicating that this region may contain a novel ROR response element. Chromatin immunoprecipitation assay showed that ROR␣ bound to the region containing this site of the promoter I.4 in MCF7 cells. Moreover, we examined clinical samples and found a correlation between ROR␣ and aromatase expression. These results suggest that ROR␣ directly activates the aromatase expression to accelerate the local production of estrogen, which results in the proliferation of breast cancer cells.

In Japan, fine needle aspiration biopsy (FNA) of the breast has long been recognized as a useful diagnostic tool, and has been used in many institutions because it provides a rapid, accurate and cost-effective evaluation. However, the use of core needle biopsy (CNB) is increasing, and vacuum assisted biopsy devices have been developed to produce larger specimens for analysis. CNB is useful because the frequency of inadequate specimens is lower than in FNA, and it requires a less invasive procedure than open biopsy. CNB is also more widely used, compared to FNA, because it can provide a more definitive diagnosis of borderline lesions and can be used to distinguish between IDC and ILC. Therefore, the use of CNB with mammographic or ultrasonographic guidance is especially high for non-palpable tumors. FNA is a rapid and non-invasive procedure that is useful for mass lesions. The accuracy of FNA for non-palpable lesions is relatively low, and depends upon the skill of the aspirators, cytoscreeners and cytopathologists involved in the procedure. However, FNA for palpable masses, coupled with a physical and mammographic examination (the so-called triple test) is highly accurate for diagnosis of breast cancer when all three modalities indicate malignancy, and for a benign lesion when all three are negative.