Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UMLS:C0178874 (
tumor progression
)
40,807
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Impairment of the complex regulatory network of cell death and survival is frequently the reason for therapy resistance of breast cancer cells and a major cause of
tumor progression
. We established two independent cell lines from a fast growing mouse breast tumor (WAP-SVT/t transgenic animal). Cells from one line (ME-A cells) are sensitive to apoptotic stimuli such as growth factor depletion or treatment with antitumor agents (e.g. doxorubicin). Cells from the second line (ME-C cells), which carry a missense mutation at the p53 codon 242, are very insensitive to apoptotic stimuli. Co-cultivation experiments revealed that the ME-C cells mediate cell death resistance to the ME-A cells. Microarray and Western blot analysis showed that
osteopontin
(
OPN
) is selectively overexpressed by the ME-C cells. This glycoprotein is the most abundant protein secreted by the ME-C cells and we obtained strong indications that
OPN
is the main antiapoptotic factor. However, the
OPN
containing ME-C cell medium does not alter the expression level of pro- or antiapoptotic genes or known inhibitors of apoptosis (IAPs). Its signaling involves mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK)1/2 as the kinase inhibitor PD98059 restores apoptosis but not the Akt inhibitor. In the ME-A cells, mitochondrial cytochrome c release occurs with and without external apoptotic stimuli.
OPN
containing ME-C cell medium does not prevent the mitochondrial cytochrome c release and caspase-9 processing. In serum starved ME-A cells, the
OPN
containing ME-C cell medium prevents caspase-3 activation. However, in doxorubicin-treated cells, although apoptosis is blocked, it does not inhibit caspase-3. This indicates that the ME-A cells distinguish between the initial apoptotic stimuli and that the cells possess a further uncharacterized control element acting downstream from caspase-3.
...
PMID:Chemotherapy resistance of mouse WAP-SVT/t breast cancer cells is mediated by osteopontin, inhibiting apoptosis downstream of caspase-3. 1716 24
Osteopontin
(
OPN
) is a chemokine like phosphorylated glycoprotein that plays important role in
cancer progression
. Extensive research from various laboratories has demonstrated the likely role of
OPN
in regulating the cell signaling that ultimately controls tumor growth and metastasis. Several earlier reports indicated that
OPN
is associated with various cancers; but its functional role in carcinogenesis is still not well defined. Besides the role of
OPN
in tumor biology, several studies have demonstrated the pathophysiological role of
OPN
in diverse biological events. This review will focus on recent advances in understanding the molecular mechanism by which
OPN
regulates a series of signaling cascades through activation of various kinases and transcription factors that ultimately control the expression of downstream effector genes, which contribute to
tumor progression
and angiogenesis in vitro and animal models. We will also provide evidences that suggest the enhanced expression of
OPN
is not only associated with several tumor types, but its level of expression is directly correlated to various stages of the clinical specimens of breast and prostate cancers. These studies may be useful for identifying novel
OPN
-based therapeutic approach for the treatment of cancer.
...
PMID:The multifaceted roles of osteopontin in cell signaling, tumor progression and angiogenesis. 1716 34
Osteopontin
(
OPN
) is expressed in various human cancers and associated with
tumor progression
, invasion and metastasis in many manners. The purpose of this study is to investigate the clinical significance of
OPN
expression in metastatic lesions of ovarian cancers, since the prognosis of the patients with peritoneal dissemination is extremely poor. In primary tumors and peritoneal metastatic lesions from 40 patients with stage III ovarian cancers, the protein levels of
OPN
and histoscores were determined by enzyme immunoassay and immunohistochemistry, respectively. Immunohistochemical staining revealed
OPN
was distributed in the cytoplasm and nuclear compartments of the cancer and stromal cells within and around the tumor. The
OPN
level was significantly (p < 0.05) increased in 32 of 40 metastatic lesions of ovarian cancers. The
OPN
increased cases identified by immunohistochemical staining were consistent with those identified by the sandwich immunoassay. The prognosis of the 32 patients with significant increase of
OPN
in ovarian cancers was extremely poor, whereas the 36-month survival rate of the 8 patients with no increase of
OPN
was 75%. Multivariate analysis revealed that the levels of
OPN
were independent predictors of prognosis from clinical characteristics (age, lesion size, histological types).
OPN
might be associated with peritoneal metastasis and its advancement, and that the
OPN
level in metastatic lesion may be a prognostic indicator in ovarian cancers.
...
PMID:Osteopontin in metastatic lesions as a prognostic marker in ovarian cancers. 1721 51
Various combinations of the SIBLING family of proteins have been found to be up-regulated in many human cancers and have been linked to different stages of
tumor progression
, including metastasis. Bone sialoprotein (BSP),
osteopontin
(
OPN
) and dentin matrix protein 1 (DMP1) specifically bind and activate MMP-2, MMP-3, and MMP-9, respectively. These proteases have also been shown to play important roles in oral squamous cell carcinoma (OSCC) invasion and metastasis. However, with the exception of
OPN
, there are no reports on the expression of the family of five SIBLING proteins in OSCC. This study examines the expression patterns of the SIBLING family (and MMP partners when known) in OSCC, correlating expression to outcome variables. Archived paraffin sections of 87 cases of primary OSCC were screened by immunohistochemistry for the SIBLINGs and their MMP partners. Three SIBLINGs (BSP, DSPP, and
OPN
), were expressed in OSCC, while DMP1 and MEPE expression were never observed. Furthermore, BSP and
OPN
were always expressed with their known MMP partners, MMP-2 and MMP-3, respectively. Poorly differentiated tumors exhibited reduced or no immunoreactivity for BSP and
OPN
but increased immunoreactivity for DSPP. Seventy eight (90%) cases were positive for BSP and DSPP, while 79 cases (91%) were positive for
OPN
. Overall, 91% of the cases were positive for at least one SIBLING. There were no correlations between SIBLING expression and tumor size ("T"; of the Union Internationale Contre le Cancer [UICC]-TNM classification for OSCC), and between SIBLING expression and lymph node spread for the T1/T2 tumors. The levels of DSPP expression for floor of mouth and retromolar region tumors were higher than for tongue tumors. Statistically significant correlations were, however, found between the expression levels of BSP and MMP-2 (p<0.0001), BSP and MMP-3 (p<0.0001), and
OPN
and MMP-3 (p<0.0024). We conclude that BSP, DSPP, and
OPN
are highly up-regulated in OSCC. While the production of these SIBLINGs is independent of T, they correlate with oral location of tumor, cognate MMP expression, and for DSPP, the degree of tumor differentiation.
...
PMID:Up-regulation of SIBLING proteins and correlation with cognate MMP expression in oral cancer. 1730 12
Osteopontin
(
OPN
) and splice variants of CD44 (CD44(V)) have independently been identified as markers for
tumor progression
. In this study, we show that both
OPN
and CD44(V) are frequently overexpressed in human gastric cancer and that
OPN
-engaged CD44(V) ligation confers cells an increased survival mediated through integrin activation. First, we show that
OPN
treatment confers cells an increased resistance to UV-induced apoptosis. The
OPN
-mediated antiapoptosis is dependent on the expression of the variant exon 6 (V6)- or V7-containing CD44 as shown by overexpression of individual CD44(V) in gastric AZ521 cells that express no or very low level of endogenous CD44 and by knockdown of the constitutively expressed V6-containing CD44 isoforms in colon HT29 cells. Although
OPN
also interacts with RGD integrins,
OPN
-RGD sequence is dispensable for
OPN
-mediated antiapoptosis.
OPN
-induced antiapoptosis is mainly attributed to the engagement of CD44(V) isoforms and the relay of an inside-out signaling via Src activity, leading to robust integrin activation. Furthermore,
OPN
-elicited antiapoptosis was observed when cells were plated on fibronectin but not on poly-D-lysin, and preincubation of cells with anti-integrin beta(1) antibody to block integrin-extracellular matrix (ECM) interaction or ectopic expression of the dominant-negative forms of focal adhesion kinase to block ECM-derived signal abolished
OPN
-induced survival, suggesting that
OPN
-elicited antiapoptotic function is propagated from matrix transduced by integrin. Taken together, we showed that
OPN
-CD44(V) interaction promotes ECM-derived survival signal mediated through integrin activation, which may play an important role in the pathogenic development and progression of gastric cancer.
...
PMID:Osteopontin promotes integrin activation through outside-in and inside-out mechanisms: OPN-CD44V interaction enhances survival in gastrointestinal cancer cells. 1733 38
Osteopontin
(
OPN
) is a multifunctional cytokine involved in cell signaling by interacting with alphavbeta3 integrins. Recent clinical studies have indicated that
OPN
expression is associated with
tumor progression
and poor prognosis among patients with lung cancer. However, the biological role of
OPN
in human lung cancer has not yet been well-defined. The purpose of this study is to investigate and provide evidence for the causal role of
OPN
regarding tumor growth and angiogenesis in human lung cancer. In this study, we developed a stable
OPN
transfectant from human lung cancer cell line SBC-3 which does not express the intrinsic
OPN
mRNA. To reveal the in vivo effect of
OPN
on tumor growth of human lung cancer, we subcutaneously injected
OPN
-overexpressing SBC-3 cells (SBC-3/
OPN
) and control cells (SBC-3/NEO) into the nude mice. Transfection with the
OPN
gene significantly increased in vivo tumor growth and neovascularization of SBC-3 cells in mice. These in vivo effects of
OPN
were markedly suppressed with administration of anti-alphavbeta3 integrin monoclonal antibody or anti-angiogenic agent, TNP-470. Furthermore, recombinant
OPN
protein enhanced human umbilical vein endothelial cell (HUVEC) proliferation in vitro, and this enhancement was significantly inhibited with the addition of anti-alphavbeta3 integrin antibody. Taken together, these results suggest that
OPN
plays a crucial role for tumor growth and angiogenesis of human lung cancer cells in vivo by interacting with alphavbeta3 integrin. Targeting the interaction between
OPN
and alphavbeta3 integrin could be effective for future development of anti-angiogenic therapeutic agents for patients with lung cancer.
...
PMID:Abrogation of the interaction between osteopontin and alphavbeta3 integrin reduces tumor growth of human lung cancer cells in mice. 1748 11
Osteopontin
(
OPN
) plays important roles in
tumor progression
and metastasis through binding to
OPN
receptors such as alpha(v)beta(beta) integrin and CD44, and its overexpression in tumor is associated poor clinical outcome of NSCLC patients. Circulating
OPN
levels, measured by ELISA in 130 NSCLC cases that had not been treated for cancer at the time of sampling, were analyzed according to clinical, pathologic parameters and single nucleotide polymorphisms (SNPs) in the
OPN
gene promoter. Advanced disease states had higher circulating levels of
OPN
(T4 versus T1-3, N3 versus N0-2, and M1 versus M0, P=.029, .001, and .001, respectively, Kruskal-Wallis H-test), reflected by higher level of
OPN
in stage IV than stage I-III (P=.029, Kruskal-Wallis H-test). Among the clinical and pathological parameters including age, gender, smoking status, histologic subtypes and grade of differentiation, smoking status influences circulating
OPN
level showing higher level of
OPN
in ex-smokers than current and non-smokers (P=.038, Kruskal-Wallis H-test). Variation at nucleotide (nt) -443 of the
OPN
gene promoter had no influence on circulating
OPN
levels, however, patients with G/G at nt -156 showed higher concentrations of
OPN
than those with G/GG or GG/GG (P=.003, Kruskal-Wallis H-test). A patient with G/G at nt -156 was more frequently diagnosed with advanced stage (IIIB-IV) than with early stage (I-IIIA) NSCLC (P=.048, Mantel-Haenszel-test). In multivariate analysis, stage is the only independent factor influencing circulating level of
OPN
. Although circulating level of
OPN
in the patients with bone metastasis was higher than in those without bone metastasis (P=.028, Mann-Whitney U-test), there was no difference in the
OPN
levels between bone metastasis group and non-bone metastasis group. Given that the elevated levels of
OPN
is associated with advanced stages of NSCLC, elucidating
OPN
regulatory mechanisms may contribute to the development of a new therapeutic modality for NSCLC.
...
PMID:Elevated circulating level of osteopontin is associated with advanced disease state of non-small cell lung cancer. 1751 4
Osteopontin
(
OPN
) is a secreted phosphoprotein, which has been reported to be associated with
tumor progression
in numerous solid tumors. In a previous transcriptome study on colorectal cancer, we identified the gene
OPN
among the most strongly up-regulated transcripts.
OPN
has been suggested as a putative target of Wnt signaling, but the molecular mechanism responsible for its aberrant transcription is not fully understood. We analyzed 13 normal colon tissues, 9 adenomas, 120 primary colon tumors, and 10 liver metastases by quantitative reverse-transcription PCR.
OPN
expression was strongly elevated in primary colon cancer and liver metastasis, but not in pre-cancerous lesions and UICC stage I tumors. Multivariate analysis established
OPN
expression as an independent prognostic parameter for overall survival. Moreover, high
OPN
expression identified a subgroup of patients with bad prognosis. Next, we determined immunohistochemically a correlation of
OPN
expression with aberrant beta-catenin staining, which is indicative of Wnt activation. Elevated expression of
OPN
was significantly correlated with increased cytoplasmic and nuclear beta-catenin staining. The in vivo role of Wnt signaling for the expression of
OPN
was tested in genetically defined mouse models with (Apc(1638N)) or without (pvillin-KRAS(V12G)) Wnt activating mutations. Mutation of the tumor suppressor APC was necessary for upregulation of
OPN
expression in the murine tumors on transcript and on protein levels. Thus,
OPN
is a transcriptional target of aberrant Wnt signaling, and
OPN
expression alone predicts survival in human colon cancer.
...
PMID:Expression of osteopontin, a target gene of de-regulated Wnt signaling, predicts survival in colon cancer. 1756 44
The persistent activation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway is oncogenic and involved in colorectal neoplasia. Mutations of both regulatory subunit and catalytic subunit of PI3K have been demonstrated in colon cancers. In the present study, we show that heterozygous disruption of the phosphatase and tensin homolog (PTEN) tumor suppressor gene promoted
tumor progression
in APC(min/+) mice. Number and size of intestinal tumors were significantly increased in mice bearing both adenomatous polyposis coli (APC) and PTEN mutations. While APC(min/+)PTEN(+/+) mice developed adenomas, invasive carcinomas developed in APC(min/+)PTEN(+/-) mice. Large tumors often resulted in intestinal intussusception and early death of APC(min/+)PTEN(+/-) mice. Targeted array revealed that
osteopontin
(
OPN
) was the leading gene whose expression was strongly induced by deficiency of PTEN. In colon cancer cells, gain-of-function mutation of PI3K robustly increased levels of
OPN
and treatment with
OPN
reduced growth factor deprivation-induced programmed cell death. Moreover,
OPN
expression was strongly increased in Ras-induced transformation of intestinal epithelial cells in a PI3K-dependent manner. Inhibition of
OPN
expression by specific small interfering RNA reduced uncontrolled growth and invasiveness of Ras-transformed intestinal epithelial cells. Thus, our results suggest that the PI3K pathway promotes the transformation of intestinal adenoma to adenocarcinoma.
OPN
, a downstream effector of PI3K, protects transformed intestinal epithelial cells from programmed cell death and stimulates their anchorage-independent growth.
...
PMID:Heterozygous disruption of the PTEN promotes intestinal neoplasia in APCmin/+ mouse: roles of osteopontin. 1769 63
Osteopontin
(
OPN
) is a highly modified integrin-binding extracellular matrix glycophosphoprotein produced by cells of the immune system, epithelial tissue, smooth muscle cells, osteoblasts, and tumor cells. Extensive research has elucidated the pivotal role of
OPN
in cell signaling that controls inflammation,
tumor progression
, and metastasis.
OPN
interaction with the integrin receptors expressed on inflammatory cells through its arginine-glycine-aspartate (RGD) and non-RGD motifs promote migration and adhesion of cells. In the liver, it has been reported that hepatic Kupffer cells secrete
OPN
facilitating macrophage infiltration into necrotic areas following carbon tetrachloride liver toxicity. Recent work has highlighted the role of
OPN
in inflammatory liver diseases such as alcoholic and nonalcoholic liver disease and T-cell-mediated hepatitis. The role of
OPN
in hepatocellular carcinoma (HCC) has also generated significant interest, especially with regards to its role as a prognostic factor.
OPN
therefore appears to play an important role during liver inflammation and cancer. In this review we will present data to demonstrate the key role played by
OPN
in mediating hepatic inflammation (neutrophils, monocytes/macrophages, and lymphocytes) and its role in HCC. Greater understanding of the pathophysiologic role of
OPN
in hepatic inflammation and cancer may enable development of novel inflammation and cancer treatment strategies.
...
PMID:Pathophysiological role of osteopontin in hepatic inflammation, toxicity, and cancer. 1789 Jul 65
<< Previous
1
2
3
4
5
6
7
8
9
10
Next >>