Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To examine the role of breast cancer stem cells (BCSCs) in metastasis, we generated human-in-mouse breast cancer orthotopic models using patient tumor specimens, labeled with optical reporter fusion genes. These models recapitulate human cancer features not captured with previous models, including spontaneous metastasis in particular, and provide a useful platform for studies of breast tumor initiation and progression. With noninvasive imaging approaches, as few as 10 cells of stably labeled BCSCs could be tracked in vivo, enabling studies of early tumor growth and spontaneous metastasis. These advances in BCSC imaging revealed that CD44(+) cells from both primary tumors and lung metastases are highly enriched for tumor-initiating cells. Our metastatic cancer models, combined with noninvasive imaging techniques, constitute an integrated approach that could be applied to dissect the molecular mechanisms underlying the dissemination of metastatic CSCs (MCSCs) and to explore therapeutic strategies targeting MCSCs in general or to evaluate individual patient tumor cells and predict response to therapy.
 ...
PMID:Cancer stem cells from human breast tumors are involved in spontaneous metastases in orthotopic mouse models. 2092 80

The retinoblastoma tumor suppressor gene (RB1; encoding RB) is often cited as a gatekeeper, whose inactivation - direct or indirect - is a rate-limiting step for tumor initiation. However, in this issue of the JCI, Sharma et al. show that RB1 loss is a late event in human prostate cancer that is coincident with the emergence of castrate-resistant metastatic disease. This role for RB1 was linked to both E2F transcription factor 1-driven upregulation of the androgen receptor (AR) and increased recruitment of the AR to target gene promoters. This unexpected function for RB1 in late-stage cancer calls upon us to reassess the significance of RB1 inactivation in other cancers in terms of its timing, function in disease etiology, and relevance for cancer therapy.
 ...
PMID:The RB tumor suppressor: a gatekeeper to hormone independence in prostate cancer? 2109 10

Serotonin producing endocrine carcinoma of small intestine (ileal carcinoid) is a clinically distinct endocrine tumor. It is generally considered as a sporadic disease and its molecular etiology is poorly understood. We report comprehensive clinical and molecular studies of 55 sporadic and familial patients diagnosed with this condition. Nine pedigrees encompassing 23 affected subjects were established, consistent with autosomal dominant mode of inheritance. Familial and sporadic patients demonstrated indistinguishable clinical pictures. Molecular analyses of 61 tumors from 45 individuals, including eight familial and 37 sporadic patients, aimed at determination of global copy number aberrations using BAC and Illumina SNP arrays and gene expression profiling by Affymetrix chips. Chromosome 18 aberrations were identified in both sporadic and in familial tumors; 100% vs. 38%, respectively. Other, less frequent aberrations were also common for both groups. Global expression profiles revealed no differentially expressed genes. Frequent gain of chromosome 7 was exclusively observed in metastases, when patient matched primary tumors and metastases were compared. Notably, the latter aberration correlated with solid growth pattern morphology (P < 0.01), a histopathological feature that has previously been related to worse prognosis. The clinical and molecular similarities identified between sporadic and familial cases suggest a common pathogenetic mechanism involved in tumor initiation. The familial variant of ileal carcinoid represents a previously unrecognized autosomal dominant inherited tumor disease, which we propose to call Familial Ileal Endocrine Carcinoma (FIEC). Our findings indicate the location of a FIEC tumor suppressor gene near the telomere of 18q, involved in development of inherited and sporadic tumors.
 ...
PMID:Common pathogenetic mechanism involving human chromosome 18 in familial and sporadic ileal carcinoid tumors. 2110 84

Post-transcriptional regulators have emerged as robust effectors of metastasis and display deregulated expression through unknown mechanisms. Here, we reveal that the human microRNA-335 locus undergoes genetic deletion and epigenetic promoter hypermethylation in every metastatic derivative obtained from independent patients' malignant cell populations. Genetic deletion of miR-335 is a common event in human breast cancer, is enriched for in breast cancer metastases, and also correlates with ovarian cancer recurrence. We furthermore identify miR-335 as a robust inhibitor of tumor reinitiation. We thus implicate the miR-335 locus on 7q32.2 as the first selective metastasis suppressor and tumor initiation suppressor locus in human breast cancer.
 ...
PMID:MicroRNA-335 inhibits tumor reinitiation and is silenced through genetic and epigenetic mechanisms in human breast cancer. 2128 68

As a model system for the understanding of human cancer, the mouse has proved immensely valuable. Indeed, studies of mouse models have helped to define the nature of cancer as a genetic disease and demonstrated the causal role of genetic events found in tumors. As an experimental platform, they have provided critical insight into the process of tumor metastasis in the lymphovascular system. Once viewed with skepticism, mouse models are now an integral arm of basic and clinical cancer research. The use of a genetically tractable organism that shares organ systems and an immense degree of genetic similarity to humans provides a means to examine multiple features of human disease. Mouse models enable development and testing of new approaches to disease prevention and treatment, identification of early diagnostic markers and novel therapeutic targets, and an understanding of the in vivo biology and genetics of tumor initiation, promotion, progression, and metastasis. This review summarizes recent mouse models for lymphangiogenesis and the process of lymphovascular metastasis, focusing on the use of the cornea as an experimental platform for lymphangiogenesis in inflammation and immunity, and on the use of molecular and viral vector mediated imaging and to identify and monitor lymph node metastases of prostate cancer.
 ...
PMID:Experimental models to study lymphatic and blood vascular metastasis. 2148 Feb 39

Stem cells play a central role in re- and generation of tissues. Special importance has been attributed to them in cancer biology. 2 entities can be discriminated: cancer infiltrating stem cells and cancer initiating stem cells. Infiltrating stem cells will be attracted to the tumor in order to be remodelled for tumor expansion, e. g. endothelial cells or other cancerous tissue components, yet these cells are per se benign. Malignant cancer stem cells are capable to generate a new tumor, histologically identical with the cancer they originate from. Many steps in cancer stem cell biology are not understood to date. It is still believed that CSC are only a minor cell fraction in tumor but capable to differentiate in hierarchical manner into any other tissue type. These stem cells are undergoing many steps of differentiation and dedifferentiation in a steady state. The factors of the micromilieu contributing to this are largely not understood. Still these steps are regarded as the key to tumor initiation, metastases and resistance to therapy. The biological functions and associated signal transduction pathways, e. g. self renewal pathways will be the key to future therapeutical strategies.
 ...
PMID:[Implication of stem cells in the biology and therapy of head and neck cancer]. 2152 29

We investigated whether SPARCL1 played an essential role in tumor initiation, formation and progression of colorectal carcinomas. In this study, we examined expression of SPARCL1 protein in the normal colorectal mucosa, adjacent normal mucosa and primary and lymph node metastases from colorectal cancer patients. In matched patients, we found that SPARCL1 was negative in the distant normal colorectal mucosa, weakly expressed in the adjacent normal mucosa, strongly expressed in primary colorectal adenocarcinomas and slightly expressed in their lymph node metastases. A similar pattern was observed in the SPARCL1 expression from our series of non-matched colorectal cancer patients. The strongest expression and highest frequency of the SPARCL1 protein were found in the primary cancers. Interestingly, in the primary tumors, the frequency of SPARCL1 expression was significantly increased from the Dukes' A to Dukes' B tumors and then decreased gradually from the Dukes' B to C and D tumors. There was no difference in the intensity of SPARCL1 expression between the central areas and invasion margins of the primary tumors. Moreover, the SPARCL1 protein was more strongly expressed in the highly differentiated tumors than the lower differentiated ones. The patients with positive expression of SPARCL1 in their tumors had worse prognosis than the patients with SPARCL1-negative ones, even after the analyses by Multivariate and Interaction method. Expression of SPARCL1 protein might be a valuable biomarker for early diagnosis in colorectal cancers and further predicting patients' prognosis.
 ...
PMID:SPARCL1: a potential molecule associated with tumor diagnosis, progression and prognosis of colorectal cancer. 2188 54

The gene encoding the receptor for hyaluronan-mediated motility (RHAMM) is overexpressed in many human cancers. However, it is unclear whether RHAMM plays a causal role in tumor initiation or progression. Using somatic gene transfer in a mouse model of islet cell tumorigenesis, we demonstrate that RHAMM isoform B (RHAMM(B)) promotes tumor growth and metastases to lymph nodes and the liver. The propensity of RHAMM(B)-expressing cells to metastasize to the liver was confirmed using an experimental metastasis assay in which cells were injected into the tail vein of immunodeficient mice. However, RHAMM(B) did not increase cell migration or proliferation in culture. In initial efforts to identify signaling pathways activated by RHAMM(B), we found that RHAMM(B) induced phosphorylation of epidermal growth factor receptor (EGFR), Erk1/2, and STAT3 and conferred susceptibility to apoptosis after treatment with an EGFR inhibitor, gefitinib. Taken together, the results indicate that RHAMM(B) promotes hepatic metastasis by islet tumor cells, perhaps through growth factor receptor-mediated signaling.
 ...
PMID:Receptor for hyaluronan-mediated motility isoform B promotes liver metastasis in a mouse model of multistep tumorigenesis and a tail vein assay for metastasis. 2194 May

Human colon cancer harbors a small subfraction of tumor-initiating cells (TICs) that is assumed to be a functionally homogeneous stem-cell-like population driving tumor maintenance and metastasis formation. We found unexpected cellular heterogeneity within the TIC compartment, which contains three types of TICs. Extensively self-renewing long-term TICs (LT-TICs) maintained tumor formation in serial xenotransplants. Tumor transient amplifying cells (T-TACs) with limited or no self-renewal capacity contributed to tumor formation only in primary mice. Rare delayed contributing TICs (DC-TICs) were exclusively active in secondary or tertiary mice. Bone marrow was identified as an important reservoir of LT-TICs. Metastasis formation was almost exclusively driven by self-renewing LT-TICs. Our results demonstrate that tumor initiation, self-renewal, and metastasis formation are limited to particular subpopulations of TICs in primary human colon cancer. We identify LT-TICs as a quantifiable target for therapies aimed toward eradication of self-renewing tumorigenic and metastatic colon cancer cells.
 ...
PMID:Distinct types of tumor-initiating cells form human colon cancer tumors and metastases. 2198 26

Inactivation of tumor suppressor gene p16/INK4A and oncogenic activation of KRAS occur in almost all pancreatic cancers. To better understand the roles of p16 in pancreatic tumorigenesis, we created a conditional p16 knockout mouse line (p16flox/flox), in which p16 is specifically disrupted in a tissue-specific manner without affecting p19/ARF expression. p16flox/flox; LSL-KrasG12D; Pdx1-Cre mice developed the full spectrum of pancreatic intraepithelial neoplasia (mPanIN) lesions, pancreatic ductal adenocarcinoma (PDA), and metastases were observed in all the mice. Here we report a mouse model that simulates human pancreatic tumorigenesis at both genetic and histologic levels and is ideal for studies of metastasis. During the progression from primary tumors to metastases, the wild-type allele of Kras was progressively lost (loss of heterozygosity at Kras or LOH at Kras) in p16flox/flox; LSL- KrasG12D; Pdx1-Cre mice. These observations suggest a role for Kras beyond tumor initiation. In vitro assays performed with cancer cell lines derived from primary pancreatic tumors of these mice showed that cancer cells with LOH at Kras exhibited more aggressive phenotypes than those retained the wild-type Kras allele, indicating that LOH at Kras can provide cancer cells functional growth advantages and promote metastasis. Increased LOH at KRAS was also observed in progression of human pancreatic primary tumors to metastases, again supporting a role for the KRAS gene in cancer metastasis. This finding has potential translational implications- future KRAS target therapies may need to consider targeting oncogenic KRAS specifically without inhibiting wild-type KRAS function.
 ...
PMID:Disruption of p16 and activation of Kras in pancreas increase ductal adenocarcinoma formation and metastasis in vivo. 2211 2


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>