Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumor-associated fibroblasts are key regulators of tumorigenesis. In contrast to tumor cells, which are genetically unstable and mutate frequently, the presence of genetically more stable fibroblasts in the tumor-stromal compartment makes them an optimal target for cancer immunotherapy. These cells are also the primary source of collagen type I, which contributes to decreased chemotherapeutic drug uptake in tumors and plays a significant role in regulating tumor sensitivity to a variety of chemotherapies. To specifically kill tumor-associated fibroblasts, we constructed an oral DNA vaccine targeting fibroblast activation protein (FAP), which is specifically overexpressed by fibroblasts in the tumor stroma. Through CD8+ T cell-mediated killing of tumor-associated fibroblasts, our vaccine successfully suppressed primary tumor cell growth and metastasis of multidrug-resistant murine colon and breast carcinoma. Furthermore, tumor tissue of FAP-vaccinated mice revealed markedly decreased collagen type I expression and up to 70% greater uptake of chemotherapeutic drugs. Most importantly, pFap-vaccinated mice treated with chemotherapy showed a 3-fold prolongation in lifespan and marked suppression of tumor growth, with 50% of the animals completely rejecting a tumor cell challenge. This strategy opens a new venue for the combination of immuno- and chemotherapies.
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PMID:Targeting tumor-associated fibroblasts improves cancer chemotherapy by increasing intratumoral drug uptake. 1679 36

CASE 1: A 64-year-old, otherwise healthy woman was referred to the surgery clinic for a presumed umbilical hernia. On physical examination, a cutaneous nodule was noted on the umbilical region and the patient was referred to the dermatology clinic. The patient was reexamined and an erythematous nodule was observed in the umbilicus measuring 2.5 cm in diameter. The patient denied pain, change in bowel habits, or weight loss. There were no other abdominal masses, no sign of ascites, and no regional lymphadenopathy. A skin biopsy from the nodule showed mucinous adenocarcinoma. Immunohistochemical staining was positive for carcinoembryonic antigen, and negative for cytokeratin (CK)7 and CK20. These results were consistent with a Sister Mary Joseph's nodule and led to the diagnosis of an occult colon carcinoma. The patient had no risk factors for colorectal carcinoma. The patient underwent surgery in another hospital, and died 3 months after the initial diagnosis of Sister Mary Joseph's nodule. CASE 2: A 73-year-old woman was referred to the dermatology clinic for evaluation of a painful, ulcerated, 3-cm lesion in the umbilicus (Figure 1). She was otherwise asymptomatic. A skin biopsy showed neoplastic glandular cells infiltrating among collagen bundles (Figure 2). Stainings for mucin and for CK7 were positive, while staining for CK20 was negative. An abdominopelvic CT scan demonstrated a 3.5-cm space-occupying lesion in the liver. Results of gastroscopy, colonoscopy, chest computed tomographic (CT) scan, and mammography were normal. Serum levels of the tumor-associated protein CA125 were elevated to 164 units, while those of CA 19-9 and carcinoembryonic antigen were within normal range. A gynecologic examination and a transvaginal ultrasound were normal. The patient had no personal or family history of any malignancy or any risk factors for developing a carcinoma. The patient was scheduled for a palliative resection of the umbilical nodule, combined with a laparoscopic inspection in search of the undetected primary tumor. She refused surgery and was lost to follow-up. She died 4 months after the initial diagnosis of umbilical metastasis. CASE 3: A 51-year-old man was aware of a silent mass in his umbilicus for 2 years without seeking medical advice. Following 2 weeks of increasing pain in this area, he was referred to the emergency room for a suspected incarcerated umbilical hernia. Surgery revealed a mass attached to the fascia and peritoneal fat. The mass was removed and diagnosed as a poorly differentiated adenocarcinoma, staining positively for carcinoembryonic antigen, and negatively for CK20, CK7, prostate-specific antigen, and prostatic acid phosphatase. Both gastroscopy and colonoscopy failed to detect the primary tumor. An abdominopelvic CT scan was normal, but a CT scan of the chest disclosed a nodule measuring 2.5 x 1.5 cm in the lower lobe of the right lung. On bronchoscopy, it was found to be an invasive adenocarcinoma, consistent with a primary tumor of the lung. The patient was a heavy smoker (45 pack-years). The patient received 4 cycles of combined chemotherapy with carboplatine and gemcitabine, with no improvement. A month later, the patient complained of abdominal pain. Following demonstration of intra-abdominal spread of disease by CT scan, a second line chemotherapy was instituted with paclitaxel. A month later the patient's condition deteriorated and he complained of cough, sweating, and pain along the right leg. A bone scan revealed bone metastases in the right femur and left tibia. Two weeks later he was admitted to the hospital with intestinal obstruction and underwent laparotomy. He had massive intra-abdominal spread of cancer and ascites. Only a palliative colostomy was performed. The patient died 3 weeks later, 9 months after the diagnosis of adenocarcinoma of the lung. The clinical data on the three patients are summarized in Table I.
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PMID:Sister Mary Joseph's nodule as a presenting sign of internal malignancy. 1695 43

Recent research shows that p53 suppresses tumor angiogenesis by transcriptionally activating the alpha(II) collagen prolyl-4-hydroxylase gene. This results in the extracellular release of the potent endogenous angiogenesis inhibitors endostatin and tumstatin from collagens 18 and 4, respectively. The involvement of these inhibitors elucidates a molecular mechanism. By simultaneously repressing a multitude of proangiogenic pathways and by inducing antiangiogenic pathways, a tumor suppressor protein can prevent an incipient tumor from switching to the angiogenic phenotype. Thus, p53 guards the genome from cancer by controlling the three fundamental processes that are critical for growth of a primary tumor and its metastases-tumor cell proliferation, apoptosis, and tumor angiogenesis.
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PMID:Tumor suppression by p53 is mediated in part by the antiangiogenic activity of endostatin and tumstatin. 1700 65

The development of a primary tumor as such is not the main cause of death, but is rather the spreading of metastases, which causes over 90% of deaths in cancer patients. This largely depends on the ability of tumor cells to migrate away from the tumor and relocate at other areas of the body. Cell migration is known to be regulated by various extracellular signal substances such as neurotransmitters. However, before single tumor cells can start to invade into distant tissue, they have to dissociate from the primary tumor. This requires the disruption of cell-cell contacts, which are provided by a plethora of adhesion molecules like the family of cadherins. Using our well, established three-dimensional collagen-based cell migration assay, we show that engagement of N-cadherin results in a significant decrease of the spontaneous and the norepinephrine-induced migration of MDA-MB-468 breast carcinoma cells, which was due to an increase in the average break length. Moreover, this N-cadherin driven influence on the migratory activity is intracellularly integrated via multiple signaling pathways. Our results show that the impact of N-cadherin on the locomotion of MDA cells involves the activation of the adenylyl cyclase and the phosphatidylinositol-3-kinase (PI3K), but is independent of the protein kinase C (PKC) alpha. In summary, we provide evidence that the engagement of N-cadherin provides a stop signal for breast carcinoma cell migration, and accordingly the use of anti-N-cadherin antibodies or soluble ligands might be a tool to inhibit metastasis formation in E-cadherin negative but N-cadherin positive tumors.
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PMID:N-cadherin engagement provides a dominant stop signal for the migration of MDA-MB-468 breast carcinoma cells. 1717 Dec 99

Gastrointestinal (GI) stromal tumors (GISTs) are the most common mesenchymal tumors specific to the GI tract, generally defined as KIT (CD117)-positive tumors with a characteristic set of histologic features. These tumors, derived from Cajal cells or their precursors, most commonly occur at the age >50 years in the stomach (60%), jejunum and ileum (30%), duodenum (4-5%), rectum (4%), colon and appendix (1-2%), and esophagus (<1%), and rarely as apparent primary extragastrointestinal tumors in the vicinity of stomach or intestines. Their overall incidence has been estimated as 10 to 20 per million, including incidental minimal tumors. GISTs are rare in children (<1%) and almost exclusively occur in stomach. They are common in patients with neurofibromatosis 1, who have a predisposition to (multiple) small intestinal GISTs. GISTs contain a spectrum from minute indolent tumors to sarcomas at all sites of occurrence. Their gross patterns are diverse, including nodular, cystic, and diverticular tumors. External involvement of pancreas and liver can simulate primary tumor in these organs. In general, gastric tumors have a more favorable prognosis than the intestinal ones with similar parameters. Gastric GISTs < or =10 cm and < or =5 mitoses per 50 HPFs have a low risk for metastasis, whereas those with >5 per 50 HPFs and >5 cm in diameter have a high risk for metastasis. In contrast, all intestinal GISTs >5 cm independent of mitotic rate have at least moderate risk for metastases, and all >5 mitoses per 50 HPFs have a high risk for metastases. Intestinal GISTs < or =5 cm with < or =5 mitoses per 50 HPFs have a low risk for metastases. Gastric GISTs can be divided into histologic subgroups including 4 spindle cell and 4 epithelioid variants. Intestinal GISTs are a histologically more homogeneous group and often contain distinctive extracellular collagen globules, skeinoid fibers. Immunohistochemical demonstration of KIT, CD34, or protein kinase theta positivity helps to properly identify these tumors.
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PMID:Gastrointestinal stromal tumors: pathology and prognosis at different sites. 1719 20

The effects of antiangiogenic therapy on tumors relapsing after irradiation are not known. To this end, we irradiated human tumors growing s.c. in nude mice with a single dose of 20 or 30 Gy. Compared with primary (treatment-naive) xenografts, the growth rate of recurrent tumors was 1.6-fold slower, which is consistent with the known "tumor bed effect." For similar size tumors, recurrences had fewer functional vessels, a reduced vessel coverage by perivascular cells, and were more necrotic. Placenta growth factor concentration was significantly lower in relapses, whereas vascular endothelial growth factor (VEGF) levels were similar between primary and recurrent tumors. On the other hand, fibrillar collagen deposition was significantly increased in recurrent tumors. This radiation-induced fibrosis was partially responsible for the slower growth of recurrences; the i.t. injection of collagenase increased the growth rate of tumor relapses without affecting primary tumor growth. The mouse-specific VEGF receptor 2-blocking antibody DC101 induced a 2.2-fold longer growth delay in recurrent tumors compared with treatment-naive tumors. DC101 significantly decreased the interstitial fluid pressure and did not change the functional vessel density and perivascular cell coverage in both tumor variants. Interestingly, DC101 induced a rapid (2 days after treatment initiation) and significant decrease in tumor cell proliferation in recurrent but not in primary tumors. Thus, our results show that the stromal compartment and the response to antiangionenic therapy of primary and in-field recurrent tumors are significantly different. Our findings suggest that antiangiogenic agents could be effective in the treatment of patients with relapses after radiotherapy.
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PMID:Human tumor xenografts recurring after radiotherapy are more sensitive to anti-vascular endothelial growth factor receptor-2 treatment than treatment-naive tumors. 1754 83

Pigment epithelium-derived factor (PEDF) is one of the most potent inhibitors of angiogenesis, and has recently been demonstrated to have an important multifunctional role in tumor growth, invasion, and metastasis. However, relatively little is known of mechanisms through which PEDF exerts its antitumor activity. Therefore, with the aim of identifying potential functional epitopes specifically against osteosarcoma, we evaluated the bioactivity of four 25-mer synthetic PEDF-derived peptides (termed StVOrth-1, -2 -3, and -4) against a human osteosarcoma cell line, SaOS-2. We found that StVOrth-2 (residues 78-102) predominantly inhibited tumor cell proliferation, while StVOrth-3 (residues 90-114) markedly increased cellular adhesion to collagen type-1, with StVOrth-4 (residues 387-411) demonstrating most significant inhibition of Matrigel invasion. Furthermore, we show that StVOrth-1 (residues 40-64), -2 and -3 induce osteoblastic differentiation, evidenced by increased mineralized nodule formation. Interestingly, although no peptide inhibited angiogenesis in the tube formation assay, StVOrth-3 and -4 markedly suppressed VEGF expression. We further tested the activity of StVOrth-2 and StVOrth-3 in vivo, in an orthotopic model of osteosarcoma and found that both peptides significantly inhibited primary tumor growth and the development of pulmonary metastases. Together these results provide greater insight into the potential mechanisms through which PEDF exerts its antitumor function. Furthermore, this raises the possibility of developing short PEDF fragments as lead compounds for the treatment of osteosarcoma.
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PMID:PEDF-derived synthetic peptides exhibit antitumor activity in an orthotopic model of human osteosarcoma. 1760 Aug 21

During carcinogenesis aberrant N-glycosylation may lead to the development of subpopulations of tumor cells with altered adhesion properties and increased invasive potential. Biosynthesis of glycans and oligosaccharides is tissue-specific and developmentally regulated by number of glycosyltransferases of which fucosyl-, sialyl- and N-acetylglucosaminyltransferases often participate in synthesis of tumor type glycans. We analyzed the expression of selected glycosyltransferases (real-time PCR): fucosyltransferases FUT-1 and FUT-4, sialyltransferase SIAT4C and beta 1,6-N-acetylglucosaminyltransferase V (MGAT-5), in human melanoma cell lines: WM35 from primary tumor site and WM239, WM9, A375 from metastatic sites. In parallel their proliferation (crystal violet test) and adhesion to fibronectin and collagen IV (BD Biocoat assay) was assessed. Examined cell lines showed expression of all studied glycosyltransferases. The level of expression of fucosyltransferases was significantly higher in melanoma cell lines from metastatic site than from primary cell line: mRNA expression of FUT-1 was 100 times higher in A375 melanoma cell line from metastatic site (A375, solid tumor) than in WM35 primary cell line. The expression of FUT-4 in cell lines from metastatic sites: WM9 (lymph node) and WM239 (skin) was respectively 80 and 37 times higher than in WM 35 primary cell line. In all melanoma cell lines very low expression of MGAT-5 and high expression of SIAT4C was observed. Melanoma cells bound both to fibronectin and to collagen IV. LTA (Lotus tetragonolobus agglutinin), the lectin that specifically recognizes fucose residue of glycans and 20mM L-fucose by itself significantly reduced adhesion of all studied cell lines, both primary and metastatic, to fibronectin (20-50 %) and to collagen IV (20-50 %). In addition LTA reduced the proliferation (20-30 %) of metastatic cell lines (A375, WM9, WM239) and did not affect the growth of primary cell line (WM35). The results suggest that higher expression of fucosyltransferases (FUT-1, FUT-4) might be an important step in the formation of surface structures that facilitate metastasis of melanoma.
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PMID:Expression of fucosyltransferases contributes to melanoma invasive phenotype. 1789 65

The prognosis for cancer patients with metastatic disease remains poor. For cancer to metastasize from a primary tumor to distinct sites in the body, both the extracellular matrix and basement membrane--physiological barriers whose primary structural constituent is collagen--must be degraded to allow the passage of tumor cells. Collagen has long been assumed to be a passive background upon which the biochemical events of metastasis take place, but recent experimental developments instead point to a novel active role for collagen in the immune response to metastasis. Along with a new hypothesis for the mechanism of collagen degradation, these data suggest innovative approaches to prevent the spread of cancer from the primary tumor site.
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PMID:Collagen--a necessary accomplice in the metastatic process. 1799 16

E-cadherin is a major cell adhesion molecule implicated as a potent tumor suppressor, which is frequently altered in human tumors including hepatocellular carcinoma. Here, we report that hepatitis C virus Core downregulates E-cadherin expression at the transcription level. This effect was abolished after treatment of 5'-Aza-2'dC, a specific inhibitor of DNA methyltransferase (DNMT). In addition, this repression was strongly correlated with hypermethylation of CpG islands of E-cadherin promoter via concerted action of both DNMT1 and 3b in Core-expressing cells. The decreased E-cadherin expression results in dramatic morphological changes in Core-expressing cells. In addition, Core-expressing cells aggregate poorly in suspension culture, reflecting their altered cell-cell interactions. The biological significance was further demonstrated by the increased collagen invasion ability of Core-expressing cells. Therefore, our finding suggests that Core plays a role in hepatocellular carcinogenesis by favoring cell detachment from the surrounding cells and migration outside of the primary tumor site.
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PMID:Hepatitis C virus core protein downregulates E-cadherin expression via activation of DNA methyltransferase 1 and 3b. 1816 8


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