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Query: UMLS:C0178874 (tumor progression)
40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The PTEN/MMAC1/TEP1 gene (phosphatase and tensin homolog deleted on chromosome 10/mutated in multiple advanced cancers/TGF-beta regulated and epithelial cell enriched phosphatase 1), which regulates the signaling pathways of Akt, is a novel tumor suppressor gene implicated in multiple cancers. Because a number of tumor suppressor genes are known to be silenced by aberrant promoter methylation, we examined the methylation status of the 5' CpG islands of PTEN using methylation-specific PCR. The altered expression of PTEN in 310 gastric carcinomas was analyzed by immunohistochemical staining using tissue-array and clinicopathologic profiles related to PTEN expression were characterized. Of 310 consecutive gastric carcinomas, 62 cases (20%) showed expression loss of PTEN. Altered PTEN expression was significantly associated with tumor depth and size, lymphatic invasion, advanced stage, pTNM stage, and patient survival (p < 0.001). The promoter methylation frequency of PTEN was found to be present in 26 (39%) of 66 cases examined, and 19 (73%) of 26 gastric cancer tissues showing promoter methylation exhibited the loss of PTEN expression. Abnormalities in the expression of PTEN significantly correlated with promoter methylation (p < 0.001). In conclusion, silencing of the PTEN gene occurs frequently in gastric carcinoma and aberrant promoter methylation is a major mechanism of silencing of the PTEN gene. The abnormalities of the PTEN gene are associated with tumor progression, metastasis, and survival.
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PMID:Promoter methylation and silencing of PTEN in gastric carcinoma. 1189 7

The ability of cancer cells to initiate specific fibroblast reactions may subsequently determine tumor evolution. In the present study we examined the coordinated expression of transforming growth factor-beta-1 (TGF-beta1), its signaling receptors, and its downstream mediator-connective tissue growth factor (CTGF)--and their impact on tumor progression and fibrogenesis in esophageal carcinomas. Messenger ribonucleic acid (mRNA) expression of TGF-beta1, CTGF, TGF-beta receptor subtype I ALK5 (TbetaR-IALK5), and TGF-beta receptor type II (TbetaR-II) was studied by Northern blot analysis in esophageal cancer and the normal esophagus. By means of immunohistochemistry and Western blot analysis, the respective proteins were localized in the tissue samples and the protein content was quantitated. Northern blot analysis revealed 3-fold and 4-fold increases (p < 0.05) in TGF-beta1 and CTGF mRNA levels, respectively, in esophageal cancer in comparison with normal controls, whereas TbetaR-I mRNA levels were significantly decreased and TbetaR-II mRNA levels were unchanged in the cancer samples. Immunostaining revealed results similar to those seen on the RNA level. TGF-beta1 and CTGF immunoreactivity were increased, TbetaR-II was unchanged, and TbetaR-IALK5 immunoreactivity was decreased. CTGF immunoreactivity was mainly present in the stroma surrounding the cancer cells but was also present in the cancer cells. The degree of fibrosis was different in squamous and adenocarcinomas and was significantly related to CTGF mRNA expression levels. The presence of CTGF in squamous cell carcinomas was associated with longer survival, whereas in adenocarcinomas it influenced survival negatively. The findings indicate that TGF-beta signaling is disturbed in esophageal cancer. CTGF, a downstream effector of TGF-beta action, differentially influences the composition of tumor microenvironment and distinct cell-matrix interactions in the two histological types of esophageal carcinoma, resulting in differences in tumor progression and patient survival.
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PMID:Connective tissue growth factor gene expression alters tumor progression in esophageal cancer. 1191 Apr 73

TGFbeta overexpression in human cancer cells has been shown to promote tumor progression. In the present study, we sought to determine whether sequestration of endogenous TGFbeta by the expression of a soluble TGFbeta type III receptor (sRIII), can reduce malignancy in human carcinoma cells and whether the tumor-suppressive activity of sRIII is associated with the inhibition of angiogenesis. Ectopic expression of sRIII significantly inhibited the growth of tumors formed by human colon carcinoma HCT116 and breast carcinoma MDA-MB-435 cells in nude mice. It also reduced the metastatic potential of the MDA-MB-435 cells. Thus, endogenous TGFbeta appears to be necessary for the progression of these two carcinomas. Furthermore, when the tumor cells were mixed with Matrigel and embedded subcutaneously in nude mice, the blood volume in Matrigel plugs containing sRIII-expressing cells as indicated by hemoglobin levels was significantly lower than that in Matrigel plugs containing the respective control cells. Blood vessel counts in paraffin sections of the Matrigel plugs containing sRIII-expressing cells were also significantly lower than those in paraffin sections of the Matrigel plugs containing control cells. Treatment of human endothelial cells with a recombinant sRIII significantly inhibited their ability to form a capillary web structure on Matrigel. These results for the first time indicate that the sRIII-induced tumor suppression appears to be in part due to the inhibition of angiogenesis.
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PMID:Extracellular domain of TGFbeta type III receptor inhibits angiogenesis and tumor growth in human cancer cells. 1203 56

Subcutaneous in vivo injections of cells of the mastocytoma line P815 in syngenic DBA/2 mice induce locally fast growing solid tumors. These have been used extensively as a cancer model to analyze and manipulate the relationship between tumor cells and host's immune defenses. We report that progression of P815 tumors in vivo was accompanied by a burst (Days 5-7) of local inflammatory cells recruitment and angiogenesis observed histologically, corroborated in vivo by MRI with gadolinium, overtranscription of macrophage activation marker genes, secretion of TNF-alpha by regional lymph node cells and concomitant systemic inflammation. No substantial overtranscriptions of either VEGF or IL-10 or TGF-beta genes were observed. Induction of COX-2 gene was a late event. To establish a possible relationship between the tumor-induced local, regional and systemic increase of pro-inflammatory mediators and progression of tumors in vivo, we carried out experiments deliberately modulating the inflammatory status of the recipient animals. Pretreatment of recipient animals by i.p. injection of thioglycolate accelerated P815 tumor growth. At the opposite, treatment of mice with either a COX-1 + COX-2 inhibitor (aspirin, 1 mg/day/mouse) or a specific COX-2 inhibitor (celecoxib, 0.13 mg/day/mouse) for 2 weeks after injection of tumor cells, significantly reduced the size and growth rate of tumors compared to control mice. Experiments carried out in vitro indicated that peritoneal macrophages from untreated animals were strongly activated by live P815 cells and by P815 membrane preparations. The tumor-induced inflammatory reaction could establish a local micro environment favoring tumor progression. The P815 tumor model might be helpful to recognize important factors controlling host/tumor relationship.
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PMID:Inflammation and cancer, the mastocytoma P815 tumor model revisited: triggering of macrophage activation in vivo with pro-tumorigenic consequences. 1212 7

TGF-beta is highly expressed in various cancer cells, yet its mechanism suppressing the cell cycle fails and cell proliferation accelerates, resulting in carcinogenesis. However, there are only a very few reports on animal experiments or clinical specimens with regard to the TGF-beta in gallbladder cancer. We performed immunohistochemical analysis of TGF-beta expression with regard to cell proliferation, angiogenesis, and tumor cell infiltration in clinical specimens of gallbladder cancer. TGF-beta immunoreactivity was significantly higher in advanced cancer than in early cancer. With regard to Ki-67 labeling index, there was no significant difference between early cancer and advanced one. There was no statistically significant difference of the density of pre-existing blood vessels (CD34) between TGF-beta-positive group and negative one. The density of angiogenic vessels (CD105) was significantly greater in the TGF-beta-positive group than in the negative one. Tumor-associated macrophage infiltration was significantly higher in the TGF-beta-positive group than in the negative one. No statistically significant differences in cumulative survival rate were noted between patients in the TGF-beta-positive and TGF-beta-negative groups. In conclusion, our study revealed that in patients with gallbladder cancer, expression of TGF-beta increases according to cancer progression and strongly influences angiogenesis and macrophage infiltration, which contributes to tumor proliferation, but acts weakly on cancer cells by itself.
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PMID:Immunohistochemical analysis of transforming growth factor beta in gallbladder cancer. 1257 67

Smad4/DPC4 is a tumor suppressor gene frequently inactivated in gastrointestinal carcinomas. Smad4 encodes a key intracellular transmitter for signals of the TGF-beta superfamily of cytokines. TGF-beta potently inhibits the growth of normal epithelial cells but tumor cells are frequently resistant; thus, it has been assumed that loss of Smad4 during tumor progression relieves this inhibition. Mediating TGF-beta responses is only one of the many putative functions of Smad4 as a signaling molecule. Smad proteins are versatile transcriptional co-modulators whose activities depend on the genetic makeup of a cell. We have used restoration of Smad4 in deficient cancer cells as an unbiased approach to decipher Smad4's tumor suppressor functions. Stable reexpression of Smad4 in human colon and pancreatic cancer cells potently suppressed tumor growth in vivo in nude mice. Surprisingly, it was not adequate to suppress tumor cell growth in vitro, nor did it restore TGF-beta responsiveness. Rather, Smad4 restoration influenced angiogenesis, decreasing expression of vascular endothelial growth factor and increasing expression of thrombospondin-1. These findings suggest that the acquisition of TGF-beta resistance and loss of Smad4 may be independent consecutive events in the tumorigenic process. They define the control of an angiogenic switch as a novel alternative mechanism of tumor suppression for Smad4.
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PMID:Smad4 transcriptional pathways and angiogenesis. 1262 15

This article will introduce a novel concept in the use of TGF-beta insensitive host immune cells in cancer therapy. TGF-beta is a multi-functional cytokine. At a cellular level, it mediates cellular proliferation, growth arrest, differentiation and apoptosis. Because of the above cellular effects, TGF-beta is able to regulate a host of patho-physiological events in vivo, such as normal embryonic development, angiogenesis in tumor tissues, malignant transformation and immune surveillance. As a general rule, its direct effect on cancer cells is inhibition to cancer growth. However cancer cells are able to acquire the ability to evade this inhibitory effect of TGF-beta by becoming insensitive to TGF-beta. Furthermore, these malignant cells are able to produce large quantities of TGF-beta. The consequence of over expression of TGF-beta by cancer cells is an important factor for subsequent tumor progression. The excess amount of TGF-beta promotes tumor angiogenesis and immune suppression. The latter effect of TGF-beta is the most devastating to the host. The present discussion is focused on the role of TGF-beta insensitive immune cells in cancer growth. The host immune system offers a natural defense program against cancer. But, this natural immune surveillance is rendered ineffective by an overproduction of TGF-beta derived from the tumor cells. Rendering the host immune cells insensitive to TGF-beta in a gene therapy program offers a hope for us to successfully combat against cancer. Based on the above discussion, it is encouraging that there is a possibility for us to achieve a cure in cancer using TGF-beta insensitive immune cells in gene therapy.
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PMID:From TGF-beta to cancer therapy. 1264 74

Tenascin-C (TN-C) and matrix metalloproteinases (MMPs) are highly expressed in cancer tissues and probably promote cell migration during cancer progression. TN-C and MMPs are often co-localized in areas of active tissue remodeling in pathologic conditions, suggesting reciprocal regulation. To investigate whether TN-C regulates MMPs expression in cancer cells, we first exposed mammary cancer cells derived from TN-C-deficient mice to TN-C and examined MMPs expression. TN-C was then compared with fibronectin (FN), laminin (LN), basic fibroblast growth factor (b-FGF) and transforming growth factor-beta1 (TGF-beta1). Results of endpoint RT-PCR, quantitative real-time RT-PCR and gelatin zymography demonstrated that TN-C, strongly and dose dependently, upregulates MMP-9 expression in murine mammary cancer cells. TN-C weakly induced MMP-2, MMP-3 and MMP-13. FN and LN induced MMP-9 to lesser extents compared with TN-C. b-FGF had no effect on MMP-9 expression. TGF-beta1 induced MMP-9 expression in a dose-dependent manner, and this induction was significantly enhanced by addition of TN-C. TN-C and TGF-beta1 also upregulated MMP-9 expression in the human breast cancer cell line MDA-MB-231. Neutralization with specific anti-TGF-beta1 antibody showed decreased expression of MMP-9, indicating that TGF-beta controls the baseline MMP-9 expression by a direct autocrine mechanism. Under neutralization of TGF-beta, addition of TN-C still upregulated MMP-9. Conversely, neutralization of endogenous TN-C (in a TN-C-positive mammary cancer cell line) downregulated TGF-beta-induced MMP-9 expression. Thus, TN-C induces MMP-9 expression directly and by collaboration with TGF-beta. These findings reveal a novel role of TN-C in breast cancer progression.
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PMID:Tenascin-C upregulates matrix metalloproteinase-9 in breast cancer cells: direct and synergistic effects with transforming growth factor beta1. 1267 30

There is evidence that transforming growth factor (TGF)beta acts as a suppressor of tumor initiation but also as a promoter of tumor progression when the antiproliferative effect of the TGFbeta signaling pathway has been overridden by other oncogenic mutations. Several somatic mutations that disrupt the TGFbeta-SMAD signaling pathway have been reported in human breast tumors. We have examined the association between single nucleotide polymorphisms (SNPs) in the TGFbeta1 gene and the incidence of invasive breast cancer in three case-control series, with a maximum of 3987 patients and 3867 controls, median age approximately 50 years, and range 22-92 years. The promoter SNP, C-509T, and the T +29C signal-peptide SNP (encoding Leu10Pro) are in strong linkage disequilibrium. They are both significantly associated with increased incidence of invasive breast cancer in a recessive manner [odds ratios: (TT versus C-carrier), 1.25; 95% confidence intervals 1.06-1.48; P = 0.009 and (ProPro versus Leu-carrier), 1.21; 95% confidence intervals 1.05-1.37; P = 0.01]. The G-800A SNP was not significantly associated with incidence of breast cancer. The C-509T SNP is not contained within a known consensus sequence for a promoter regulatory element and therefore unlikely to affect TGFbeta1 expression, whereas the Leu10Pro signal peptide substitution potentially affects TGFbeta1 secretion. Transfections of HeLa cells with constructs encoding either the Pro or Leu forms of TGFbeta1 and driven by the cytomegalovirus promoter indicate that the signal peptide with Pro at residue 10 causes a 2.8-fold increase in secretion compared with the Leu form. These data indicate that the allele encoding Pro10 is associated with increased rates of TGFbeta1 secretion and with increased incidence of invasive breast cancer for the population samples described. It is estimated that 3% of all breast cancer cases may be attributable to Pro10 homozygosity.
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PMID:A transforming growth factorbeta1 signal peptide variant increases secretion in vitro and is associated with increased incidence of invasive breast cancer. 1275 Feb 87

Bone morphogenetic protein 7 (BMP-7) is an important regulator of cell development and differentiation of various organs. Tumorigenesis and tumor progression are also strongly associated with changes of the fate of cells which are highly differentiated in healthy tissues. Therefore, we studied the role of BMP-7 in breast cancer cell lines and in breast tumor tissue samples. BMP-7 is expressed in various cell lines, but in a cell line specific manner. The breast cancer cell lines MCF-7 and SK-BR-3 showed BMP-7 expression on the mRNA level. In T-47D we were not able to detect BMP-7 on the mRNA but on the protein level. Additionally, epidermal growth factor (EGF), a stimulator of proliferation, was not able to enhance BMP-7 expression on the transcriptional level. These findings are in contrast to the EGF-dependent regulation of BMP-6, indicating a differential regulation of these closely related TGF-beta members. In order to confirm the data obtained from cell cultures, we analyzed normal breast tissue and tumor tissue samples from 170 invasive ductal carcinomas of the breast by immunohistochemistry. We found BMP-7 expression in normal breast tissue in the end buds, but not in the ductus lactiferus. BMP-7 protein was detected in all 170 tumor samples. Comparing BMP-7 levels with histopathological parameters, we could not show a correlation of BMP-7 and the proliferation index nor with erbB receptors. But the expression of BMP-7 was highly correlated with estrogen receptor levels (p< or=0.01) and progesterone receptor levels (p< or =0.01) which are important markers for breast cancer prognosis and therapy.
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PMID:Differential expression and regulation of bone morphogenetic protein 7 in breast cancer. 1279 80


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