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At least 343 records · Page 19Linked to original sources
PubMed2004

Predictors of viridans streptococcal shock syndrome in bacteremic children with cancer and stem-cell transplant recipients.

PURPOSE: To describe episodes of viridans streptococcal bacteremia (VSB) in a cohort of children with cancer and stem-cell transplant (SCT) recipients and to determine predictors of viridans streptococcal shock syndrome (VSSS) in this group of children. PATIENTS AND METHODS: For this retrospective review, we included episodes of VSB isolated between March 1997 and September 2002, in children (<or= 18 years) with a diagnosis of cancer or SCT patients. The primary outcome was VSSS, defined as hypotension requiring intravascular volume expansion or inotropic support and/or respiratory insufficiency necessitating assisted ventilation. RESULTS: Eighty-eight episodes of VSB occurred in 79 children. The mean age of the children was 6.7 years (range, 0.6 to 18.0 years). The most common underlying diagnosis was acute myelogenous leukemia (AML) in 31 (35%) of 88 episodes, and 38 (43%) of 88 had undergone SCT. VSSS occurred in 16 (18%) of 88 episodes, and two children died from VSSS. Two variables were predictive of VSSS, namely peak temperature at presentation (odds ratio [OR], 6.3; 95% CI, 2.1 to 19.0; P =.001) and inpatient status (OR, 5.9; 95% CI, 1.3 to 28.0; P =.02). Diagnosis of AML (OR, 1.1; 95% CI, 0.4 to 3.5; P =.8), receipt of SCT (OR, 1.9; 95% CI, 0.6 to 5.7; P =.2), high-dose cytarabine (OR, 0.6; 95% CI, 0.1 to 3.2; P =.6), and mucositis (OR, 0.8; 95% CI, 0.3 to 2.6; P =.7) were not predictive of VSSS. CONCLUSION: VSSS occurred in 18% of episodes of VSB in children with cancer or SCT recipients. Peak temperature before antibiotic therapy and inpatient status were predictive of VSSS.

Adolescent↗
PubMed2000

Epithelial stem cell repertoire in the gut: clues to the origin of cell lineages, proliferative units and cancer.

Gastrointestinal stem cells are shown to be pluripotential and to give rise to all cell lineages in the epithelium. After damage, gut stem cells produce reparative cell lineages that produce a wide range of peptides with important actions on cell proliferation and migration, and promote regeneration and healing. Increase in stem cell number is considered to induce crypt fission, and lead to increases in the number of crypts, even in the adult; it is also the mode of spread of mutated clones in the colorectal mucosa. Stem cell repertoire is defined by both intrinsic programming of the stem cell itself, but signalling from the mesenchyme is also vitally important for defining both stem cell progeny and proliferation. Carcinogenesis in the colon occurs through sequential mutations, possibly occurring in a single cell. A case is made for this being the stem cell, but recent studies indicate that several stem cells may need to be so involved, since early lesions appear to be polyclonal in derivation.

Animals↗
PubMed2006

Stem cells of ependymoma.

Ependymomas are tumours that arise throughout the central nervous system. Little is known regarding the aberrant cellular and molecular processes that generate these tumours. This lack of knowledge has hampered efforts to reduce the significant mortality and morbidity that are associated with ependymoma. Here, we review recent data that suggest that radial glia are cells of origin of ependymoma, and discuss the processes that might transform these neural progenitors into ependymoma cancer stem cells.

Brain Neoplasms↗
PubMed2007

Gastric and intestinal phenotypic correlation between exocrine and endocrine components in human stomach tumors.

We have previously suggested that an origin of a stomach cancer is from a progenitor cell specializing toward exocrine cell (Exo-cell) lineages. To clarify whether our hypothesis is correct or not, we analyzed the expression of Exo-cell and endocrine cell (End-cell) markers in a series of lesions for comparison. We evaluated chromogranin A (CgA) expression in 37 early and 73 advanced stomach cancers, in 30 stomach adenomas, in 8 carcinoid tumors, and in 4 endocrine cell carcinomas (ECCs) with assessment of gastric and/or intestinal (G/I) phenotypes in both Exo-cell and End-cell by immunohistochemistry. CgA expression was observed in 10.8% of the early and 16.4% of the advanced stomach cancers, respectively. The End-cell G/I phenotypes were in line with the Exo-cell counterparts in the CgA-positive stomach cancerous areas, and there was strong association between Cdx2 expression and the intestinal End-cell markers. All of the adenoma cases had the intestinal Exo-cell phenotypic expression, with the positive link between Exo-cell and End-cell G/I phenotypes. All stomach carcinoids had CgA expression but no expression of Exo-cell markers. In conclusion, most stomach cancers might develop from a progenitor cell specializing towards Exo-cell lineages, but some cases possessed both Exo-cell and End-cell markers with maturely differentiated phenotypes. In such cases, Exo-cell and End-cell phenotypes were found to correlate strongly, suggesting the possibility of histogenesis from "cancer stem cells".

Adenocarcinoma↗
PubMed2006

Metastasis: a question of life or death.

The metastatic process is highly inefficient--very few of the many cells that migrate from the primary tumour successfully colonize distant sites. One proposed mechanism to explain this inefficiency is provided by the cancer stem cell model, which hypothesizes that micrometastases can only be established by tumour stem cells, which are few in number. However, recent in vitro and in vivo observations indicate that apoptosis is an important process regulating metastasis. Here we stress that the inhibition of cell death, apart from its extensively described function in primary tumour development, is a crucial characteristic of metastatic cancer cells.

Animals↗
PubMed2007

TGFBR3 loss and consequences in prostate cancer.

BACKGROUND: Resistance to transforming growth factor-beta (TGF-beta) is important in tumorigenesis. TGF-beta resistance mechanisms in prostate cancer are not well understood. METHODS: We have conducted a systematic analysis of TGF-beta pathway components with a meta-analysis of seven microarray studies using Oncomine and evaluated the results of TGFBR3 expression in prostate cell lines. Furthermore, we knocked down TGFBR3 in prostate epithelial cells and analyzed the consequences of TGFBR3 knockdown. RESULTS: We found that TGFBR3 is the TGF-beta component most commonly downregulated among localized human prostate cancer studies. TGFBR3 knockdown led to focus formation and enhanced expression of CD133, a marker found on prostate cancer stem cells. DNA microarray analysis of TGFBR3 knockdown cells identified 101 genes regulated by TGFBR3. Seven of these genes show a corresponding decrease in clinical prostate cancer specimens, which include genes involved in prostate mass and vasculature. CONCLUSIONS: TGFBR3 downregulation is an important step in prostate tumorigenesis.

Blotting, Western↗
PubMed2005

Stem-like cells in bone sarcomas: implications for tumorigenesis.

Bone sarcomas are a clinically and molecularly heterogeneous group of malignancies characterized by varying degrees of mesenchymal differentiation. Despite advances in medical and surgical management, survival rates for high-grade tumors have remained static at 50% to 70%. Tumor stem cells have been recently implicated in the pathogenesis of other heterogeneous, highly malignant tumors. We demonstrate here the existence of a small subpopulation of self-renewing bone sarcoma cells that are capable of forming suspended spherical, clonal colonies, also called "sarcospheres," in anchorage-independent, serum-starved conditions. These bone sarcoma cells as well as tissue specimens express activated STAT3 and the marker genes of pluripotent embryonic stem (ES) cells, Oct 3/4 and Nanog. Expression levels of Oct 3/4 and Nanog are greater in sarcospheres than in adherent cultures. A subset of bone sarcoma cells displays several surface markers of mesenchymal stem cells (Stro-1, CD105, and CD44) as well as attributes of mesodermal, ectodermal, and endodermal differentiation. Although previously documented in brain and breast tumors, our results support the extension of the cancer stem cell hypothesis to include tumors of mesenchymal lineage. Furthermore, they suggest the participation of ES cell homeobox proteins in non-germ cell tumorigenesis.

Bone Neoplasms↗
PubMed2006

Future directions in the second-line treatment of non-small cell lung cancer.

Single-agent chemotherapy has shown limited activity as second-line treatment in metastatic non-small cell lung cancer (NSCLC), with short-lived responses and modest survival benefit over best supportive care or placebo. There are multiple ways to improve the poor outcome of patients whose disease progresses after first-line chemotherapy. First, individualizing second-line chemotherapy could optimize its effect; the discovery of dramatic responses and significant improvement in survival in patients with epidermal growth factor receptor (EGFR) gene mutations who are treated with EGFR tyrosine kinase inhibitors may lead to the application of other novel therapeutic approaches. Cancer vaccines, using autologous tumor cells genetically modified with granulocyte-macrophage colony-stimulating factor, constitute a new therapeutic option for patients with chemoresistant advanced NSCLC. Vaccines based on lymphocyte-defined tumor antigens, such as melanoma-associated antigen-3, toll-like receptor 9, and mucin 1, are also in the first stages of testing and have shown promising preliminary results. New approaches in gene therapy, including a p53-based method, are currently being investigated. The ultimate goal of gene therapy is to target cancerous stem cells, the importance of which is beginning to be recognized in NSCLC through the study of abnormalities in the wingless (Wnt) pathway. At the preclinical level, small interfering RNA sequences have been used successfully to neutralize multiple abnormal components of the Wnt pathway.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2026

Chaperone-mediated autophagy as a regulator of hallmarks of cancer.

Chaperone-mediated autophagy (CMA) is a selective lysosomal degradation pathway that maintains cellular homeostasis by degrading soluble proteins containing KFERQ-like motifs. Although CMA has traditionally been recognized for its role in protein quality control and cellular stress adaptation, increasing evidence shows that it is frequently altered in cancer, where it regulates multiple processes that promote tumor initiation, progression, and therapy resistance. The growing number of identified CMA substrates involved in cell proliferation, apoptosis, metabolism, DNA damage response, immune regulation, inflammation, and cellular plasticity suggests that CMA is much more than a protein degradation pathway; it is an important regulator of tumor adaptation. In this review, we bring together current evidence to provide a comprehensive understanding of how CMA contributes to the Hallmarks of Cancer, including sustained proliferative signaling, resistance to cell death, metabolic reprogramming, invasion and metastasis, immune evasion, and the enabling characteristics of genome instability and tumor-promoting inflammation. We further explore the emerging roles of CMA in cellular plasticity and cancer stem cell maintenance, two interconnected processes that drive tumor progression, metastasis, and therapeutic resistance. By integrating evidence from diverse tumor types, this review provides a comprehensive understanding of how CMA shapes multiple hallmarks of cancer by selectively degrading key regulatory proteins. Finally, we highlight the context-dependent roles of CMA, identify key gaps in our current understanding, and discuss the opportunities and challenges of targeting CMA for cancer therapy. Overall, this hallmark-based perspective provides an integrated understanding of how CMA contributes to multiple hallmarks of cancer and supports its potential as a therapeutic target.

autophagy↗
PubMedDate not supplied

Stem cell-based treatments for gynecological solid tumors.

BACKGROUND AND OBJECTIVE: We have recently assisted to an increasing scientific interest and a new research effort in the field of stem cell-based therapy. Since the late 1980s hematopoietic stem cells (HSC) have been used to set up therapeutic strategies for the treatment of solid tumors such as gynecological cancers. In this context, different approaches have been suggested and clinically investigated. STATE OF THE ART: In the autologous setting we can describe the well-known use of HSC as hematologic support to high-dose chemotherapy regimens, and the use of HSC as a source of dendritic cells for cancer vaccination protocols. In our institution a long-term experience has been developed in high-dose chemotherapy with autologous HSC transplantation as first-line treatment of advanced ovarian cancer, and in the use of cytokines both for HSC collection and for post-transplantation hematopoietic recovery and immune reconstitution. An alternative approach consists of allogenic HSC transplantation following either myeloablative/standard or non-myeloablative/reduced conditioning regimens, which have been proposed as new adoptive immunotherapeutic treatments for different non-hematologic malignancies. PERSPECTIVES: Future strategies in the use of HSC in oncology comprise the possibility of HSC ex-vivo expansion, the use of umbilical cord blood HSC, and the development of HSC-based gene-therapy programs. Further investigations are expected in the new field of cancer stem cells.

Antineoplastic Agents↗
PubMed2005

Validation of molecular targets in prostate cancer.

As prostate cancer is not a single disease, it is important to identify the pivotal pathway in the patient being treated. The molecular environment is the site of current oncological research to define new therapeutic targets for hormone-refractory disease, offering the potential to eventually individualize treatment through stratification of pathways. Targets may be validated either phenotypically (e.g. androgen receptor, cadherin) or functionally (e.g. prostate cancer-specific genes). In addition, several other candidates are potentially suitable, while others await discovery. Important initial steps have been made in the search for prostate cancer stem cells; identifying stem cells and the stromal, hormonal, and other signalling molecules that influence their behaviour would have important implications for managing prostate cancer. Although individual therapeutic pathways might be ineffective in a particular molecular environment, combinations of approaches might be capable of producing synergistic effects. A multimodal approach thus might be the best solution. Determining where best to search for a molecular target, and validating whether the target is associated with a sufficiently aggressive malignant process to justify further study is difficult, but the potential benefits are enormous.

Androgens↗
PubMed2025

High p62 and ALDH1A3 Reduce the Effectiveness of Endocrine Therapy in Luminal B Breast Cancer.

BACKGROUND/AIM: High expression of p62 and ALDH1A3 indicates a poor clinical outcome in luminal B breast cancer, and p62 is involved in the progression of ALDH1-positive luminal B breast cancer stem cells. However, the association between endocrine therapy and high p62 and ALDH1A3 expression, in luminal B breast cancer remains unclear. MATERIALS AND METHODS: Two datasets with gene expression and clinical data for patients with primary breast cancer (METABRIC, n=2,509; The Cancer Genome Atlas, n=1,084) were downloaded and statistically analyzed. To evaluate the association between the p62 and ALDH1A3 expression levels and endocrine therapy, including tamoxifen and aromatase inhibitor, in patients with luminal B breast cancer, disease-specific survival was examined using Kaplan-Meier and multivariate Cox regression analyses. RESULTS: Patients with p62 high ALDH1A3 high luminal B breast cancer treated with endocrine therapy exhibited a poor prognosis. Moreover, patients with p62 high ALDH1A3 high luminal B breast cancer treated with tamoxifen showed a trend towards a poor prognosis, but those treated with aromatase inhibitors showed a significantly poor prognosis. These results suggest that endocrine therapy, especially aromatase inhibitors, exhibits a reduced effectiveness against p62 high ALDH1A3 high luminal B tumors. CONCLUSION: p62 and ALDH1A3 could be used together as a prognostic biomarker for predicting the efficacy of endocrine therapy for luminal B breast cancer.

ALDH1A3↗
PubMed1988

Detection of small cell lung cancer bone marrow metastases by tumor stem cell assay.

Detection of small cell lung cancer (SCLC) bone marrow (BM) metastases has a prognostic implication in itself and a therapeutic interest in the setting of autologous bone marrow transplantation. In a prospective study involving 68 bone marrow samples, we compared SCLC detection results obtained using a tumor stem cell assay and those obtained using conventional morphology by light microscopy. In agar, tumoral cells were stimulated either by Salmon's conditioned medium or by epidermal growth factor (EGF). Tumoral clonogeneic cells were detected in 11 cases, although 7 of these were considered negative when investigated by light microscopy. On the contrary, metastases were detected by morphology in 8 instances where no growing colonies were revealed by tumor stem cell assay. The choice of stimulating factor did not seem critical since the number of colonies was similar in all the cases. We conclude that the tumor stem cell assay is useful in the detection of small cell lung cancer bone marrow metastases, particularly in cases where these metastases have failed to be recognized through light microscopy investigation. However, the sensitivity of this assay is low and should be complemented by other techniques such as immunodetection.

Bone Marrow Cells↗
PubMed2006

Targeted therapy by disabling crossroad signaling networks: the survivin paradigm.

Embedded in the concept of targeted cancer therapy is the expectation that disabling a single oncogenic pathway will eliminate the tumor cells and leave the normal tissues unscathed. Although validated by clinical responses in certain malignancies, challenges exist to generalize this approach to most tumors, as multiple genetic lesions, chromosomal instability, insensitivity of the cancer stem cell compartment, and emergence of drug resistance complicate the identification and therapeutic exploitation of a single, driving oncogenic pathway. Instead, broader therapeutic prospects may be offered by targeting crossroad signaling networks that are selectively exploited in cancer and oversee multiple aspects of tumor cell maintenance. One such pathway is centered on survivin, a cancer gene that intersects cell proliferation, cell survival, and the cellular stress response. Several clinical trials targeting survivin with a collection of approaches from immunotherapy to small-molecule antagonists are currently under way. By simultaneously disabling multiple signaling circuitries, targeting survivin may provide a novel perspective in rational cancer therapy selective for specific cancer mechanisms but broadly applicable to disparate tumors regardless of their genetic makeup.

Genetic Therapy↗
PubMed2005

Combined fibrolamellar carcinoma and cholangiocarcinoma exhibiting biphenotypic antigen expression: a case report.

Fibrolamellar carcinoma (FLC), a variant of hepatocellular carcinoma (HCC), very rarely occurs in association with cholangiocarcinoma (CC). This report describes the first case of FLC coexisting with CC (FLC-CC) from Japan. Although the major part of the tumour located in the right lobe of the liver showed the typical features of FLC, CC was admixed with the FLC, not only in the primary hepatic tumour, but also in the lymph node metastases. Immunohistochemical analysis revealed that, although carcinoembryonic antigen (CEA), which can be detected with monoclonal antibodies in the cytoplasm and the cell surface of CC cells but not HCC cells, was expressed in only the CC cells in the primary tumour, it was expressed extensively in the cytoplasm of both CC and FLC cells in the metastatic and recurrent tumours. Furthermore, Hep Par 1, a hepatocyte specific antigen, was also expressed in both the FLC and CC cells. These findings suggest that, in this case, both FLC and CC were possibly derived from the same cancer stem cell with the capacity to differentiate into both hepatocytes and bile duct epithelium, and that both the cellular components, therefore, exhibited biphenotypic antigen expression.

Adolescent↗
PubMed2006

Mesenchymal stem cells inhibit proliferation and apoptosis of tumor cells: impact on in vivo tumor growth.

Mesenchymal stem cells (MSC) have received much attention in the field of hematopoietic stem cell transplantation because not only do they support hematopoiesis but also exhibit a profound immunosuppressive activity that can be exploited to prevent undesired alloreactivity. We have previously shown that their immunosuppressive activity is mainly exerted at the level of T-cell proliferation. Here, we show that MSC exhibit a similar antiproliferative activity on tumor cells of hematopoietic and non hematopoietic origin. In vitro, MSC produced the transient arrest of tumor cells in the G(1) phase of cell cycle; this was accompanied by a reduction in the apoptotic rate even when survival factors were limiting. However, when tumor cells were injected into non-obese diabetic-severe combined immunodeficient mice in conjunction with MSC, their growth was much faster as compared to the group receiving only tumor cells. To explain the discrepancy between the in vitro and in vivo behavior, we suggest that MSC have the ability to form a cancer stem cell niche in which tumor cells can preserve the potential to proliferate and sustain the malignant process. We conclude that the clinical use of MSC in conditions in which a malignant disease is involved should be handled with extreme caution.

Adult↗
PubMed1996

Transfusion and stem cell support in cancer treatment.

Intensification of therapeutic regimens, improved patient survival, and advances in cytokine and cellular therapies have led to increasingly complex requirements for transfusion and stem cell support in cancer treatment. This article focuses on current and evolving issues in red blood cell, platelet, and granulocyte transfusion support, as well as measures to avoid increasingly important complications of transfusion therapy, such as alloimmunization, graft-versus-host disease, cytomegalovirus infection, and immunomodulation. Issues concerning current applications of hematopoietic stem cell transplantation and future prospects also are discussed.

Blood Transfusion↗
PubMed2000

[High dose chemotherapy with autologous stem cell support in cancer patients].

INTRODUCTION: In 1996 it was decided that high-dose chemotherapy with peripheral stem cell support should be offered by all five university hospitals in Norway. MATERIAL AND METHODS: We report on the first 49 patients from the western part of Norway treated with this modality at Haukeland University Hospital in the 1996-98 period. RESULTS: All patients had a total of > 2-10(6) CD34 positive cells/kg collected before high-dose chemotherapy. To achieve this critical stem cell dose, five patients had to have three or more stem cell collections; four of them had to be mobilised several times. Poor stem cell mobilisation was mostly marked in patients with soft tissue sarcoma and testicular cancer, but was also observed in a few heavily pre-treated patients with non-Hodgkins lymphoma. With the exception of one lymphoma patient who developed a rapid bone marrow relapse, all patients had satisfactory sign of bone marrow regeneration after reinfusion of the stem cells. This also applied to the poor mobilisors. No treatment-related deaths have occurred. Four to 38 months after high-dose therapy, 33% of patients with multiple myeloma and 52% of patients with malignant lymphoma were alive and in complete remission. Three of the four patients with soft tissue sarcoma relapsed 3-7 months after high-dose chemotherapy.

Adolescent↗