Tag: invasion

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Leptin Stimulates Rat Aortic Smooth Muscle Cell Proliferation and Migration

Leptin, a peptide secreted from adipose tissue, plays an important role in the regulation of food intake and energy expenditure. In obese patients, plasma leptin levels are elevated and obesity is one of the major risk factors for cardiovascular diseases. Therefore, in this study, we investigated the effect of leptin on vascular smooth muscle cell (VSMC) functions. Cultured rat aortic VSMC expressed 130-kDa short form of leptin receptor. Leptin stimulated both proliferation and migration of VSMC. Leptin stimulated phosphorylation and activation of mitogen-activated protein (MAP) kinases, and also increased phosphatidylinositol (PI) 3-kinase activity. Further, two distinct PI 3-kinase inhibitors, wortmannin and LY294002 inhibited the migratory effect of leptin. These results demonstrate that leptin is a proliferative and migratory factor for VSMC, implying that leptin may play a role in the formation and development of vascular lesions.

link to pdf at http://www.ncbi.nlm.nih.gov/pubmed/11729375

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In vitro anti-angiogenic properties of LGD1069

LGD1069 (Targretin®) is a selective retinoid X receptor (RXR) ligand, which is used in patients for cutaneous T-cell lymphoma. Our published study reported that LGD1069 inhibited tumor-induced angiogenesis in non-small cell lung cancer. In present study, we found that LGD1069 suppressed the proliferation, adhesion, invasion and migration of endothelial cells directly, and affected the expression of vegf and some matrix genes.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3120806/

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Tumorigenicity of Human Breast Cancer Is Associated with Loss of the Ca21- activated Chloride Channel CLCA2

The human Ca21-activated chloride channel-2 (CLCA2) is expressed in
normal breast epithelium but not in breast tumors of different stages of
progression. Northern analysis of nontransformed and transformed
breast epithelial cell lines revealed CLCA2 expression in the nontransformed
cell line MCF10A and the nontumorigenic cell line MDA-MB-453,
whereas all tumorigenic cell lines were negative (MDA-MB-231, MDAMB-
435, MDA-MB-468, and MCF7). When stably reintroduced into
CLCA2-negative MDA-MB-231 and MDA-MB-435 cells, CLCA2 expression
reduced Matrigel invasion in vitro and inducibility of s.c. and metastatic
tumors of MDA-MB-231 cells in nude mice. Our results suggest that
CLCA2 may act as a tumor suppressor in breast cancer.

cancerres.aacrjournals.org/content/59/21/5488.full.pdf

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A Rapid in Vitro Assay for Quantitating the Invasive Potential of Tumor Cells

We have reconstituted a matrix of basement membrane onto a filter in
a Boyden chamber and assessed the ability of various malignant and
nonmalignant cells to penetrate through the coated filter. Cells from all
the malignant cell lines tested were able to cross the matrix in 5-6 h,
whereas human fibroblasts as well as mouse 3T3 and lOT’/i cell lines,
which are not tumorigenic, were not invasive. In addition, normal primary
prostate epithelial cells and benign prostatic hyperplasia cells were not
invasive when tested in this assay, whereas malignant prostate carcinoma
cells were highly invasive. Parallel experiments with these prostatic cells
using the intrasplenic assay for metastasis detection in the nude mouse
confirmed the benign behavior of the former cells and the metastatic
phenotype of the latter ones. These results suggest that this in vitro test
allows the rapid and quantitative assessment of invasiveness and a means
to screen for drugs which alter the invasive phenotype of tumor cells.

.pdf downloadable at http://www.ncbi.nlm.nih.gov/pubmed/2438036

Note: do not autoclave acrylic chambers as this article recommends.

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Insulin-like Growth Factor (IGF)-binding Protein-4 Inhibits Colony Formation of Colorectal Cancer Cells by IGF-independent Mechanisms

Effects of insulin-like growth factor-binding protein-4 (IGFBP-4) on proliferation, colony formation, and cell migration were assessed in IGF-sensitive and -insensitive colorectal cancer cell lines. In IGF-insensitive Isreco-1 cells, overexpression of IGFBP-4 reduced colony formation but not cell proliferation and migration, whereas exogenous IGF-II had no effect. In IGF-dependent LS1034 cells, IGFBP-4 inhibited all parameters of growth tested, whereas IGF-II partially restored reduced proliferation and cell migration only. In Isreco-2 cells, which lack endogenous IGF expression but are IGF sensitive, colony formation was also reduced by IGFBP-4. Therefore, specific parameters of malignant progression of colon carcinoma cells are distinctly affected by IGF-dependent and IGF-independent effects of IGFBP-4.

http://cancerres.aacrjournals.org/content/64/5/1600.full

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Tumorigenicity of Human Breast Cancer Is Associated with Loss of the Ca21- activated Chloride Channel CLCA2

The human Ca21-activated chloride channel-2 (CLCA2) is expressed in
normal breast epithelium but not in breast tumors of different stages of
progression. Northern analysis of nontransformed and transformed
breast epithelial cell lines revealed CLCA2 expression in the nontransformed
cell line MCF10A and the nontumorigenic cell line MDA-MB-453,
whereas all tumorigenic cell lines were negative (MDA-MB-231, MDAMB-
435, MDA-MB-468, and MCF7). When stably reintroduced into
CLCA2-negative MDA-MB-231 and MDA-MB-435 cells, CLCA2 expression
reduced Matrigel invasion in vitro and inducibility of s.c. and metastatic
tumors of MDA-MB-231 cells in nude mice. Our results suggest that
CLCA2 may act as a tumor suppressor in breast cancer.

cancerres.aacrjournals.org/content/59/21/5488.full.pdf