Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alterations in the tissue microenvironment collaborate with cell autonomous genetic changes to contribute to neoplastic progression. The importance of the microenvironment in neoplastic progression is underscored by studies showing that fibroblasts isolated from a tumor stimulate the growth of preneoplastic and neoplastic cells in xenograft models. Similarly, senescent fibroblasts promote preneoplastic cell growth in vitro and in vivo. Because senescent cells accumulate with age, their presence is hypothesized to facilitate preneoplastic cell growth and tumor formation in older individuals. To identify senescent stromal factors directly responsible for stimulating preneoplastic cell growth, we carried out whole-genome transcriptional profiling and compared senescent fibroblasts with their younger counterparts. We identified osteopontin (OPN) as one of the most highly elevated transcripts in senescent fibroblasts. Importantly, reduction of OPN protein levels by RNA interference did not affect senescence induction in fibroblasts; however, it dramatically reduced the growth-promoting activities of senescent fibroblasts in vitro and in vivo, showing that OPN is necessary for paracrine stimulation of preneoplastic cell growth. In addition, we found that recombinant OPN was sufficient to stimulate preneoplastic cell growth. Finally, we show that OPN is expressed in senescent stroma within preneoplastic lesions that arise following 7,12-dimethylbenz(a)anthracene/12-O-tetradecanoylphorbol-13-acetate treatment of mice, suggesting that stromal-derived OPN-mediated signaling events affect neoplastic progression.
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PMID:Senescent stromal-derived osteopontin promotes preneoplastic cell growth. 1915 1

Vitamin D receptor (VDR) can modulate functionally antagonistic growth regulatory pathways, involving beta-catenin/E-cadherin on one hand and osteopontin (OPN) on the other. This study investigates effects of VDR ligand treatment on the balance of these discordant signals and on associated cell behavior. Treatment of Rama 37 or SW480 cells by 1alpha,25-(OH)(2) D(3) or analogs suppressed beta-catenin/Lef-1/Tcf signaling and upregulated E-cadherin, consistent with a cancer-inhibitory action. Conversely, treatment also increased transcription of OPN that may be implicated in tumor progression. Molecular crosstalk was observed between the antagonistic VDR-dependent signals, in that beta-catenin/Lef-1/Tcf molecules modulated VDR activation of OPN. Treatment effects on cell growth were related to a constitutive balance of OPN and E-cadherin expression. No growth effects were observed in Rama 37 cells that have low OPN and high E-cadherin expression. Conversely, treatment of Rama 37 stably transfected subclones that had high OPN and/or low level E-cadherin induced small but significant increases of cell attachment to fibronectin, anchorage-independent growth or invasion. This study shows that relative expression levels of key VDR downstream genes may influence growth regulation by 1alpha,25-(OH)(2) D(3) or analogs. These findings may be relevant to the cell- or tissue-specificity of vitamin D growth regulation.
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PMID:Vitamin D receptor modulates the neoplastic phenotype through antagonistic growth regulatory signals. 1918 84

Osteopontin is a tumor-associated protein that promotes tumor development and metastasis. The preoperative blood samples of 94 oral squamous cell carcinoma (OSCC) patients and 28 healthy individuals were analyzed for plasma osteopontin levels, and another 256 paraffin-embedded OSCC specimens were analyzed by osteopontin immunostaining. The patients with advanced tumor (T) stage (T3/T4 vs. T1/T2) and positive nodal (N) status had significantly higher plasma levels of osteopontin (both p<0.001). Positive osteopontin immunostaining also correlated significantly with advanced T stage (p<0.001), positive N status (p<0.001), advanced TNM stage (p<0.001) and male gender (p=0.016). Unfavorable cumulative 5-year overall survival rates correlated significantly with positive osteopontin immunostaining (p<0.001), advanced T stage (p<0.001), positive N status (p<0.001) and advanced TNM stage (p<0.001). However, Cox regression analysis revealed that T stage and N status were independent prognostic factors for survival (both p<0.001) and osteopontin immunostaining was marginally significant for survival (p=0.056). The present study demonstrated that high expression level of osteopontin in either the plasma or the tumor of the patients with OSCC was associated with tumor progression, suggesting that osteopontin expression is an important prognostic factor for OSCC.
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PMID:Comprehensive study on the prognostic role of osteopontin expression in oral squamous cell carcinoma. 1921 94

The purpose of this study was to investigate various serum markers of bone turnover in non-small cell lung cancer patients (NSCLC) in the presence or absence of bone metastasis. Our retrospective study included 79 newly diagnosed NSCLC patients. Group A included 51 patients with bone metastasis and group B included 28 patients that never developed bone metastasis. The measurement of bone formation markers, bone resorptive markers and osteoclastogenesis markers as well as routine biochemical analysis was determined. Patients with bone metastasis had an increase in receptor activator of nuclear factor kappaB ligand, osteopontin and osteoprotegerin. Patients who later developed bone metastasis had decreased osteocalcin and tartrate-resistant acid phosphatase isoform 5b levels (TRACP-5b). We also found an unusually low TRACP-5b/RANKL ratio for patients who have or later developed metastasis. In patients that never developed bone metastases, cross-linked carboxy-terminal telopeptide of type I collagen was increased. Positive correlations were found between osteopontin and TRACP-5b, and also between bone alkaline phosphatase with osteocalcin and TRACP-5b. In conclusion, serum markers of bone turnover may be able to determine the time-to-tumor progression, metastatic potential and overall survival of the NSCLC patient. In addition, they may contribute to a more accurate follow-up and tailored treatment options.
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PMID:The clinical significance of serum markers of bone turnover in NSCLC patients: surveillance, management and prognostic implications. 1944 81

Malignant tumors are characterized by dysregulated cell growth and the metastasis of secondary tumors. Numerous studies have documented that osteopontin (OPN) plays a key role in regulating tumor progression and metastasis. Here, we show that the overexpression of OPN in human embryo kidney-293 cells significantly increases both the level of cell proliferation, by provoking the G(1)/S transition, and the level of cell migration in vitro. These findings suggest that augmented OPN contributes to cell growth and motility. Inhibiting OPN or the pathway it stimulates may therefore represent a novel approach for the treatment of primary tumors and associated metastases.
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PMID:Overexpression of human osteopontin increases cell proliferation and migration in human embryo kidney-293 cells. 1956 70

Osteopontin (OPN) is highly expressed in cancer patients and plays important roles in many stages of tumor progression, such as anti-apoptosis, proliferation, and metastasis. From functional screening of human cDNA library, we isolated OPN as a caspase-8 substrate that regulates cell death during hypoxia/reoxygenation (Hyp/RO). In vitro cleavage assays demonstrate that OPN is cleaved at Asp-135 and Asp-157 by caspase-8. Cellular cleavage of OPN is observed in apoptotic cells exposed to Hyp/RO among various apoptotic stimuli and its cleavage is blocked by zVAD or IETD caspase inhibitor. Further, over-expression of OPN, the form with secretion signal, inhibits Hyp/RO-induced cell death. Caspase cleavage-defective OPN mutant (OPN D135A/D157A) is more efficient to suppress Hyp/RO-induced cell death than wild-type OPN. OPN D135A/D157A sustains AKT activity to increase cell viability through inhibition of caspase-9 during Hyp/RO. In addition, OPN is highly induced in some tumor cells during Hyp/RO, such as HeLa and Huh-7 cells, which is associated with their resistance to Hyp/RO by sustaining AKT activity. Notably, OPN C-terminal cleavage fragment produced by caspase-8 is detected in the nucleus. Plasmid-encoded expression of OPN C-terminal cleavage fragment increases p53 protein level and induces apoptosis of wild-type mouse embryonic fibroblast cells, but not p53(-/-) mouse embryonic fibroblast cells. These observations suggest that the protective function of OPN during Hyp/RO is inactivated via the proteolytic cleavage by caspase-8 and its cleavage product subsequently induces cell death via p53, postulating caspase-8 as a negative regulator of tumorigenic activity of OPN.
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PMID:Intracellular cleavage of osteopontin by caspase-8 modulates hypoxia/reoxygenation cell death through p53. 1970 14

Secretion of osteopontin (OPN) by cancer cells is a known mediator of tumorigenesis and cancer progression in both experimental and clinical studies. Our work demonstrates that OPN can activate Akt, an important step in cancer progression. Both ILK and PI3K are integral proteins in the OPN/Akt pathway, as inhibition of either kinase leads to a loss of OPN-mediated Akt activation. Subsequent to OPN-induced Akt activation, we observe inactivation of GSK-3beta, a regulator of beta-catenin. Osteopontin stimulation leads to an overall increase in beta-catenin protein levels with a resultant transfer of beta-catenin to the nucleus. Through the nuclear import of beta-catenin, OPN increases both the transcription and protein levels of MMP-7 and CD44, which are known TCF/LEF transcription targets. This work describes an important aspect of cancer progression induced by OPN.
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PMID:Osteopontin induces beta-catenin signaling through activation of Akt in prostate cancer cells. 1985 36

Runx2, a bone-specific transcriptional regulator, is abnormally expressed in highly metastatic prostate cancer cells. Here, we identified the functional activities of Runx2 in facilitating tumor growth and osteolysis. Our studies show that negligible Runx2 is found in normal prostate epithelial and non-metastatic LNCaP prostate cancer cells. In the intra-tibial metastasis model, high Runx2 levels are associated with development of large tumors, increased expression of metastasis-related genes (MMP9, MMP13, VEGF, Osteopontin) and secreted bone-resorbing factors (PTHrP, IL8) promoting osteolytic disease. Runx2 siRNA treatment of PC3 cells decreased cell migration and invasion through Matrigel in vitro, and in vivo shRunx2 expression in PC3 cells blocked their ability to survive in the bone microenvironment. Mechanisms of Runx2 function were identified in co-culture studies showing that PC3 cells promote osteoclastogenesis and inhibit osteoblast activity. The clinical significance of these findings is supported by human tissue microarray studies of prostate tumors at stages of cancer progression, in which Runx2 is expressed in both adenocarcinomas and metastatic tumors. Together these findings indicate that Runx2 is a key regulator of events associated with prostate cancer metastatic bone disease.
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PMID:Runx2 association with progression of prostate cancer in patients: mechanisms mediating bone osteolysis and osteoblastic metastatic lesions. 1991 14

Osteopontin (OPN) is a secreted glycoprotein implicated to function in cancer development and metastasis. Although elevated expression of OPN are observed in cancer cells of various types, in some cases, only the cells in the stromal region surrounding the tumor express OPN, suggesting distinct functional roles for this protein derived from host cells and from cancer cells. To provide a model for addressing the functions and mechanisms of host-derived OPN in cancer progression and metastasis, a cutaneous squamous cell carcinoma cell line (ONSC) that lacks the OPN gene, Spp1, was established. This line of cells was derived from a squamous cell carcinoma that developed in a female, OPN-null mouse subjected to two-stage skin carcinogenesis. Morphologically, ONSC cells resemble epithelial cells, and they express the epithelial markers, K1, K14, and p63, as confirmed by immunohistochemical analyses. Genomic analyses indicate the presence of mutated H-Ras and p53 genes. ONSC cells form colonies in soft agar and, subcutaneously injected into athymic nude mice, develop into squamous cell carcinomas that metastasize to the lungs. Lacking OPN expression, these squamous cell carcinoma cells provide a model to address the function of host OPN in the context of cancer progression and metastasis.
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PMID:Establishment and characterization of an osteopontin-null cutaneous squamous cell carcinoma cell line. 1991 34

Deregulation of signal transducer and activator of transcription (STAT)-3 signaling plays crucial role in oncogenesis of various cancers. However, the molecular mechanism by which osteopontin (OPN), a chemokine-like extracellular matrix-associated protein, regulates STAT3 activation that leads to tumor progression and inhibits apoptosis in breast cancer cells is not well understood. In this study, we for the first time report that OPN upregulates alphavbeta3 integrin-mediated Janus kinase 2 (JAK2) phosphorylation and STAT3 activation in breast cancer (MDA-MB-468 and MCF-7) cells. Pretreatment of cells with JAK2 inhibitor (AG 490) suppresses OPN-induced STAT3 phosphorylation, its nuclear localization and DNA binding indicating that JAK2 is involved in this process. Transfection of cells with wild-type (wt) STAT3 enhanced whereas mutant STAT3 (STAT3 Y705F) suppressed OPN-induced breast tumor cell migration. Treatment of cells with OPN followed by staurosporine (STS) showed that OPN protects the cells from STS-induced apoptosis. Moreover, transfection of cells with wt STAT3 upregulates whereas STAT3 Y705F downregulates Bcl2 and cyclin D1 expressions in response to OPN. Interestingly, STAT3-overexpressing cells when injected to non-obese diabetic/severe combined immunodeficiency mice followed by OPN treatment, the mice developed enhanced tumor growth as compared with STAT3 Y705F-injected mice or mice injected with OPN alone. The levels of Bcl2 and cyclin D1 in wt STAT3 tumors were significantly higher than controls. Clinical specimen analysis revealed that increased OPN and pSTAT3 expressions correlate with enhanced breast tumor progression. Thus, targeting OPN and its regulated STAT3 signaling could be a potent therapeutic approach and understanding these mechanisms may form the basis of new therapeutic regimen for the management of breast cancer.
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PMID:Activation of JAK2/STAT3 signaling by osteopontin promotes tumor growth in human breast cancer cells. 1992 37


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