PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “tumor stemness”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1979

[Facial myokomias in brain stem tumors].

Four cases of brain-stem tumor were described, in which myokymias were electromyographically derived from the region of several cerebral nerves. An attempt is made to interpret the effects of twitching by reference to the electromyogram. Myokymias are a positive indication of organic brain stem damage. The use subtle techniques of electromyographic examination shows that this muscular hyperkinesis is not so infrequent a symptom as is generally believed.

Abducens Nerve↗
PubMed1979

Irradiation of primary brain-stem tumors.

Of 40 patients treated for brain-stem tumors, 20 had lesions of the thalamus and midbrain (group A) and 20 had lesions of the pons and medulla (group B). Performance status measured 1 month after irradiation improved in 16 of 20 group A and 11 of 20 group B patients and was a valuable prognostic factor. The survival rate at 5 years was 40% (8/20) in group A and 30% (6/20) in group B. All recurrences appeared within 3 years and were predominantly locoregional. Treatment factors, including dose and field size, are analyzed.

Adolescent↗
PubMed1978

Quantitation of differential sensitivity of human-tumor stem cells to anticancer drugs.

With a direct in vitro tumor-colony assay developed to measure sensitity of human-tumor stem cells to anticancer drugs, we performed 32 retrospective or prospective clinical studies in nine patients with myeloma and nine with ovarian cancer treated with standard agents that were tested in vitro. The results were clearly correlated (P is less than 0.00001). Unique patterns of sensitivity and resistance to the six drugs tested were observed for individual patients. In eight cases of myeloma and three of obarian carcinoma in vitro sensitivity corresponded with in vivo sensitivity whereas in one case of myeloma it did not. In vitro resistance correlated with clinical resistance in all five comparisons in myeloma and all 15 in ovarian cancer. We conclude that this assay shows sufficient promise to warrant larger-scale testing to determine its efficacy for selection of new agents and individualized cancer chemotherapy regimens.

Antineoplastic Agents↗
PubMed1979

Biopsy of pediatric brain stem tumors.

26 patients, average age of 7.3 years, has biopsies of a brain stem tumor. 62% of the patients presented with hydrocephalus, and ventriculoperitoneal shunts were placed 7-10 days prior to biopsy. The midbrain was biopsied 13 times, the pons 3 and the medulla 12 times. Tissue for histopathologic examination was obtained at each operation and demonstrated astrocytoma in 13 patients, glioblastoma in 6, 'no tumor seen' in 5 and ependymoma in 2. Astrocytomas were usually located in the upper brain stem, and all of the glioblastomas were located in the medulla. The operative mortality was zero, and the morbidity was largely related to increased cranial nerve deficit. All the astrocytoma patients were treated with radiation only; whereas, 4 patients with glioblastoma were treated with vincristine, CCNU and methylprednisone in addition to radiation as described by the Children's Cancer Study Group (CCG-944). 3 patients with 'no tumor' were not treated and are alive and well 15-41 months following operation. 2 patients with no tumor were treated, one as a glioblastoma multiforme, subsequently verified at postmortem examination, and one as a midbrain astrocytoma. 1 patient with astrocytoma died 3 months following operation, all the remainder are living and well 4-51 months following operation. Irrespective of the treatment, all 7 patients with glioblastoma expired within 9 months of diagnosis. The prognosis for survival for patients with brain stem astrocytoma is superior to those with glioblastoma multiforme. Specific histopathologic correlation with clinical management may lead to improved and prolonged survival for patients with brain stem glioma.

Astrocytoma↗
PubMed1979

Preparation of permanent slides of intact soft-agar colony cultures of hematopoietic and tumor stem cells.

A simple technique is described for fixing colony-containing layers of soft agar and drying them onto microscopic slides. The method is extrapolated from techniques used in immunology for permanent preservation of immunodiffusion or immunoelectrophoresis plates. Slides prepared in this fashion are eminently suitable for subsequent analysis with a variety of techniques including conventional Papanicolaou or other staining methods as well as histochemistry, immunofluorescence, and autoradiography. In addition to research applications, the technique may have diagnostic applications and should greatly enhance both qualitative and quantitative analysis of the biology of hematopoietic and tumor colony formation.

Agar↗
PubMed1975

Radiation of infratentorial and supratentorial brain-stem tumors.

A retrospective survey of 41 patients with unbiopsied thalamic, pontine, and medullary tumors treated with radiation therapy demonstrated 30% to 40% 3-year survival, with seven long-term survivors. Eleven of the 12 patients surviving over 3 years have essentially normal neurological function. Of seven patients in whom histological diagnoses were eventually obtained, four proved to have glioblastomas and three low-grade astrocytomas. Autopsy revealed that all glioblastomatous tumors extended beyond the treatment field; this suggested that larger volumes, perhaps the whole brain, should be irradiated. High doses (at least 5000 rads) should be used since the 3-year survival among those receiving such doses was 45%.

Adolescent↗
PubMed2026

Development and internal validation of a six-gene prognostic model based on galactose metabolism for overall survival in lung adenocarcinoma.

BACKGROUND: Lung cancer remains a leading cause of cancer incidence and mortality globally. Metabolic reprogramming promotes tumor progression and shapes an immunosuppressive tumor microenvironment. Galactose metabolism is involved in multiple malignancies, but its prognostic value in lung adenocarcinoma (LUAD) remains unclear. This study aimed to develop and internally validate a galactose metabolism-related multigene prognostic model for LUAD. METHODS: A retrospective prognostic model development and internal validation study was performed using RNA sequencing (RNA-seq) and clinical data from 585 LUAD patients in The Cancer Genome Atlas (TCGA). Differential expression, functional enrichment, univariate and multivariate Cox regression were applied to construct a prognostic gene signature. Internal validation was performed using bootstrap resampling. Model performance was evaluated by time-dependent receiver operating characteristic (ROC), C-index, calibration, and Kaplan-Meier analysis. Associations between the model and immune infiltration, immunotherapy responsiveness, and tumor stemness were also analyzed. RESULTS: A six-gene prognostic model (GALT, GANC, PGM1, GALM, B4GALT1, PGM2) was developed. The model showed good discrimination with 1-, 3-, and 5-year area under the curve (AUC) values of 0.719, 0.693, and 0.684, respectively. The low-risk group exhibited significantly longer survival, increased antitumor immune infiltration (CD8+ T cells, M1 macrophages, activated CD4+ memory T cells), higher expression of T cell proliferation-related genes, lower immune checkpoint expression, better predicted immunotherapy response, and lower tumor stemness compared with the high-risk group. CONCLUSIONS: We developed and internally validated a six-gene prognostic model for LUAD based on galactose metabolism. The model shows moderate prognostic performance and is associated with antitumor immunity and tumor stemness. It may be used for prognostic risk stratification and to guide personalized immunotherapy in LUAD.

Galactose metabolism↗
PubMed1977

Primary bioassay of human myeloma stem cells.

The ability to clone primary tumors in soft agar has proven useful in the study of the kinetics and biological properties of tumor stem cells. We report the development of an in vitro assay which permits formation of colonies of human monoclonal plasma cells in soft agar. Colony growth has been observed from bone marrow aspirates from 75% of the 70 patients with multiple myeloma or related monoclonal disorders studied. Growth was induced with either 0.02 ml of human type O erythrocytes or 0.25 ml of medium conditioned by the adherent spleen cells of mineral oil-primed BALB/c mice. 5-500 colonies appeared after 2-3 wk in culture yielding a plating efficiency of 0.001-0.1%. The number of myeloma colonies was proportional to the number of cells plated between concentrations of 10(5)-10(6) and back-extrapolated through zero, suggesting that colonies were clones derived from single myeloma stem cells. Morphological, histochemical, and functional criteria showed the colonies to consist of immature plasmablasts and mature plasma cells. 60-80% of cells picked from colonies contained intracytoplasmic monoclonal immunoglobulin. Colony growth was most easily achieved from the bone marrow cells of untreated patients or those in relapse. Only 50% of bone marrow samples from patients in remission were successfully cultured. Tritiated thymidine suicide studies provided evidence that for most myeloma patients, a very high proportion of myeloma colony-forming cells was actively in transit through the cell cycle. Velocity sedimentation at 1 g showed myeloma stem cells sedimented in a broad band with a peak at 13 mm/h. Antibody to granulocyte colony-stimulating factor did not reduce the number or size of the colonies. Increased numbers of myeloma colonies were seen when the marrow was depleted of colony-stimulating factor elaborating adherent cells before plating. This bioassay should prove useful in studying the in vitro biological behavior of certain bone marrow-derived (B)-cell neoplasia. In addition, systematic and predictive studies of anticancer drug effects on myeloma stem cells should now be feasible.

Antigen-Antibody Reactions↗
PubMed1979

Demonstration of low density lipoprotein receptors in mouse teratocarcinoma stem cells and description of a method for producing receptor-deficient mutant mice.

Familial hypercholesterolemia, a widespread human genetic disorder implicated in vascular and coronary disease, has had no laboratory animal counterpart that would enable the pathogenesis to be analyzed and drugs to be tested in vivo. The primary lesion in some patients is known to occur in the cells' initial handling of the major cholesterol-carrying lipoprotein of plasma. It entails a deficiency in the specific cell surface receptor that binds low density lipoprotein (LDL), with a consequent alteration in the control of cholesterol metabolism. The present study was undertaken to devise a practical scheme for producing, from developmentally versatile mouse teratocarcinoma stem cells, whole-animal models with a comparable genetic lesion. This requires first learning whether the tumor stem cells in culture express LDL receptors, and next establishing a selection or screening procedure to identify receptor-deficient mutants in mutagenized cell cultures. The results show that the teratocarcinoma cells do in fact have specific high-affinity LDL receptors which are similar to those reported for fibroblasts and the parenchymal cells of specialized tissues and different from those of phagocytic cells. Sterols suppressed the otherwise efficient binding, internalization, and degradation of LDL ((125)I-labeled) by the cells. Acetylation of LDL blocked the binding. Only LDL and not high density lipoprotein (HDL) was bound. After LDL uptake and degradation, the liberated cholesterol led, as expected, to increased cholesteryl ester formation; it also suppressed activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase [HMG CoA reductase; mevalonate: NADP(+) oxidoreductase (CoA-acylating), EC 1.1.1.34], the rate-limiting step in cholesterol biosynthesis. Cells with LDL receptors were readily visualized by administering a fluorescent derivative of LDL; in the fluorescence microscope, labeling was seen in all cells. Cells with experimentally depressed receptors, yielding little fluorescence, were separable from those with normal fluorescence in the fluorescence-activated cell sorter. Thus, two methods for isolating receptor-deficient cells from mutagenized cultures are now available, either by visual recognition of low-fluorescing or nonfluorescing colonies in culture plates or by electronic cell sorting. Such mutants in an appropriate line of teratocarcinoma cells can then be passaged into blastocysts for full somatic tissue differentiation and germ-line development into mice.

Animals↗
PubMed1975

Radiation therapy of tumors of the central nervous system in childhood.

The results of radiation therapy for CNS tumors of childhood are presented and discussed according to histologic type. In this material the 5-year recurrence-free survival rates were about 35% for medulloblastomas, 48% for the hypothalamic and brain stem tumors, 86% for lowgrade ependymomas, and 57% for germinomas. Complications or CNS injury from irradiation were rare and the quality of life in survivors was generally good. Current methods of radiation therapy may possibly improve these results. Tumors of the CNS in children do not necessarily carry a hopeless prognosis; aggressive therapy is indicated.

Astrocytoma↗
PubMed2026

Integrating single-cell transcriptomics to construct an oncogene-driven prognostic model and elucidate metabolic-immune crosstalk in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths, its progression and treatment heterogeneity are mainly influenced by driver gene and tumor micro-environment (TME) interactions. Nevertheless, the mechanisms of this process at the single-cell level remain unclear. This study integrated TCGA and multi-center single-cell transcriptome data to identify a 575 genes HCC-specific core set, developing a single-cell "oncogene scoring" system to quantify individual carcinogenic activity. This score is significantly elevated in malignant and proliferative T cells and is closely associated with metabolic reprogramming, aberrant cell‒cell communication, and immunosuppressive phenotypes. Based on these characteristics, we constructed a machine learning-based Random Survival Forest (RSF) prognostic model validated in multiple independent cohorts, which classifies patients into distinct risk subtypes. The high-risk group exhibits genomic instability, increased tumor stemness, and immune evasion, while the low-risk group was more sensitive to drugs such as sorafenib. This study highlights the potential pathways by which high oncogenic activity is associated with HCC progression, suggesting a profound link with single-cell metabolic‒immune crosstalk. The constructed RSF model offers a promising computational framework for risk stratification and provides hypothesis-generating insights that may inform future personalized treatment strategies for HCC patients.

Hepatocellular carcinoma↗
PubMed1979

Effect of some cytostatics on the haemopoietic stem cells (CFUs) in blood.

The effect of some cell-cycle stage-specific cytostatics on the pluripotent stem cells (CFUs) present in the blood was investigated. The amount of these cells in the blood responds markedly and very quickly to a single administration of any of these drugs. Their effects on the circulating CFUs allowed the drugs tested to be divided into groups: (1) Hydroxyurea and arabinosyl cytosine induced a profound decrease in the number of CFUs in the blood, which was followed by a return to the normal value and an overshoot that lasted several days; (2) Colchicine, vinblastine, vincristine, and methotrexate first induced an increase in the number of CFUs in the blood, which was followed by a decrease to below the normal values, and still later an overshoot that lasted several days. The preliminary data on the effect of hydroxyurea on the CFUs circulating in large quantities in the blood of mice with Friend virus leukaemia indicate that the tumorous stem cells (CFUs) might respond to these cytostatics in a similar way.

Animals↗
PubMed1979

Nickel sub-sulphide-induced leiomyosarcoma in rabbit white skeletal muscle: a light microscopical and ultrastructural study.

Nickel sub-sulphide-induced leiomyosarcomas in rabbit white skeletal muscle were studied by both light and electron microscopy. Two types of tumor cells, small spindle cells and elongated smooth muscle cells, are revealed by light microscopy. Nevertheless, their ultrastructure displays the same general feature. The most differentiated cells have abundant cytoplasmic filaments 7 nm in diameter, kept together in bundles by dense bodies. There also exist many 10 nm filaments and a large number of microtubules. The nuclei have prominent nucleoli with an extensive nucleolonema which form an irregular tridimensional network. Distinct fibrillar nuclear bodies were observed. Sometimes there exist desmosomes or gap junctions. The Golgi apparatus produces coated vesicles with secretory function. In the tumors were generally found the Ni3S2 implantations surrounded by a capsule, the major component of which were collagen fibers, degenerated nuclei and rod-like structures with a transverse periodicity of 15.5 nm. From these observations, several characteristics should be pointed out: 1) Many tumor cells contain large nucleoli and distinct intranuclear inclusions of undetermined nature. 2) The coated vesicles represent a secretory activity of the tumor cells; the coat material is probably used during the formation of cell membranes. Another possible function of coated vesicles could be the sequestering of calcium ions. 3) The rod-like structures in the Ni3S2-including capsule are not of Z-line material. 4) The tumoral stem myoblast in heart and skeletal muscle arise from mesenchymal cells.

Animals↗
PubMed1978

Ultrastructural study of tumor cell differentiation in osteosarcoma of jaw bones.

Tw osteosarcomas of jaw bones have been studied by electron microscopy. The objectives were to examine the specific cell types in relation to functions and ultrastructural features, and to examine matrices produced by tumor cells. The osteosarcoma cells were subdivided into four cell types: anaplastic, chondroblastic, osteoblastic, and osteocytic--giant cells were not considered in the present investigation. Compared to normal bone cells, no specific sign of malignancy was found. However, tumor cells seem to lose functional abilities, i.e. a modification of matrix. Consequently, tumor matrix has altered organic and inorganic components with impairment of collagen maturation and matrix mineralization. The alteration in both processes may be related to a diminished production of proteoglycans. The cytogenic hypothesis of a tumor stem cell may be supported by the identification of anaplastic osteosarcoma cells resembling immature reticulum cells. One may speculate on transformation of this cell type as a genetically predetermined osteoprogenitor cell of malignant potential.

Adult↗