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)

MHC class I antigens participate in the immune response by presenting peptides to CD8+ cytotoxic T cells. Decreased expression of these antigens in tumor cells may contribute to an evasion of immune system and consequently to enhanced tumor growth. However, not all tumors expressing low levels of HLA antigens show increased malignancy, probably as a result of the differential activity of the oncogenes involved in malignant transformation. The ras family of cellular oncogenes is one of the most frequently detected families of transformation-inducing genes in human solid tumors. The aim of this work is to study the expression of MHC antigens and the ras oncogene product, p21ras, in 60 primary breast tumors in order to define its clinical significance in tumor progression. HLA antigen expression and p21ras levels were measured on breast tumors using immunohistochemistry methods and enzymoimmunoassay, respectively. The results demonstrate that more invasive tumors have both a decreased expression of HLA class I antigens and higher levels of p21ras protein expression than less aggressive tumors. These findings indicate that the capacity of breast cancers to grow and metastasize is related to low levels of MHC class I antigens and enhanced p21ras expression, thus supporting the involvement of MHC and ras oncogenes in breast tumor malignancy.
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PMID:MHC class I antigen expression is inversely related with tumor malignancy and ras oncogene product (p21ras) levels in human breast tumors. 129 32

Three complementary DNA encoding S19 ribosomal protein (S19), laminin-binding protein (LBP), and HLA class I (HLA-I) genes were isolated from a colon tumor-enriched subtraction library. To evaluate this mRNA expression, surgically removed colon tumors as well as matched normal tissue and human colon carcinoma cell lines showing various differentiation states, anchorage dependence, and proliferation states were examined by Northern blot analysis. The mRNA level of S19 mRNA (0.6 kilobase) was higher in primary colon carcinoma tissue than in matched normal colon tissue in 5 of 6 cases. In 2 of 4 cases, the expression of LBP mRNA (1.2 kilobases) was higher in carcinoma than in normal tissue. In 12 human colon cell lines, the level of LBP mRNA was higher in poorly differentiated cells. On the other hand, HLA-I mRNA (1.7 kilobases) was higher in well-differentiated cells. Although the S19 mRNA was expressed in both well- and poorly differentiated cells, a concomitant increase with tumor progression was observed in two pairs of cell lines derived from the same patients (SW480 and SW620; COLO201 and COLO205). Anchorage dependence of butyrate-treated HT29 colon carcinoma cells was correlated with lower levels of S19 and LBP mRNAs and higher levels of HLA-I mRNA expression compared with untreated cells. While the expression of S19 and LBP mRNAs was not changed due to cell growth states, HLA-I mRNA levels were found to be low in proliferating HT29 cells but highly induced in contact-inhibited cells. In summary, therefore, high expression of S19 and LBP combined with low expression of HLA-I were well correlated with colon carcinoma cells of higher malignant potential.
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PMID:Differential expression of S19 ribosomal protein, laminin-binding protein, and human lymphocyte antigen class I messenger RNAs associated with colon carcinoma progression and differentiation. 133 4

The distribution of MHC antigens in human melanocytic lesions, i.e. HLA class I and HLA class II antigens is reviewed. HLA class I antigens have a broad distribution, but may be lost during tumor progression. In contrast, HLA class II antigen expression appears with neoplastic transformation. The mode of regulation of HLA antigens in melanoma lesions is complex. Immunohistochemical demonstration of HLA antigen expression in primary melanoma lesions and in locoregional metastases has prognostic relevance. Expression of HLA-DR in primary melanoma lesions is associated with an unfavorable prognosis, as is a decreased expression of HLA-A,B,C antigens in locoregional metastases.
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PMID:MHC antigens in human melanomas. 191 17

Malignant transformation of melanocytes and further neoplastic progression may be associated with qualitative and/or quantitative changes in expression of HLA class I and class II antigens. Since previous immunohistochemical studies of surgically removed melanoma lesions have suggested a relationship in the expression of HLA class I and class II antigens, we have investigated the expression of these antigens at the single cell level. Double immunofluorescence staining of frozen sections of melanoma metastases and immunoelectron microscopic double labelling of melanoma cell suspensions prepared from three of these lesions has detected three HLA phenotypes on the large majority of melanoma cells: either both HLA class I and class II antigens, neither HLA antigen or only HLA class I antigens. In four out of the 11 lesions a few melanoma cells were found to express HLA class II antigens and to lack HLA class I antigens. A relationship was also found in the level of expression of HLA class I and class II antigens, as estimated by the intensity of staining with monoclonal antibodies. The level of expression of HLA class II antigens appeared to be similar to or lower than that of HLA class I antigens on the large majority of melanoma cells. This coordinated heterogeneity in the expression of HLA class I and class II antigens by melanoma cells may have implications in the interactions of tumour cells with the host's immune system.
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PMID:Associated expression of HLA class I and class II antigens on melanoma cells in surgically removed metastases. 353 48

The altered expression of histocompatibility leukocyte antigens (HLA) in the development to cervical carcinoma suggests that tumor progression may be related to impaired recognition by host immune defense mechanisms. To investigate whether this phenomenon plays a role in the process of metastasis of cervical cancer, we analyzed and compared the HLA expression with the number of infiltrating immune cells in primary cervical carcinoma and related autologous metastases (n = 30) by staining serial paraffin and corresponding frozen sections with a panel of monoclonal antibodies. In 60% of the cervical metastases, compared to 21% of the primary tumors, a downregulation of monomorphic HLA class I antigens was observed, with frequent allele-specific alterations. In 50% the HLA class II expression was slightly increased on the metastatic tumor cells in comparison to the primary tumor. In addition, variability of alterations in HLA expression was observed between different metastases in the same patient. A minor infiltration of immune cells was present in cervical metastases compared to the primary tumors, especially in the HLA class I-downregulated metastases. Furthermore, loss of HLA class I expression on the metastatic tumor cells resulted in a significant decrease of tumor-infiltrating CD8+ T lymphocytes. These findings suggest that in cervical carcinoma loss of HLA class I expression plays a decisive role in the escape from immune surveillance leading to a greater metastatic potential of tumor cells.
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PMID:Altered HLA expression by metastatic cervical carcinoma cells as a factor in impaired immune surveillance. 777 40

Flow cytometric analysis reveals that 5 human melanoma cell lines (M14, IGR3, ME1477, JUSO, GLL19) express both alpha and beta chain of the interleukin 2 receptor (IL-2R alpha and IL-2R beta). These chains are able to specifically bind IL-2 and to form high-affinity heterodimers (IL-2R alpha beta). Analysis of poly A+ RNAs by Northern blot reveals the presence of typical transcripts for both the IL-2R alpha gene (3.6 kb) and the IL-2R beta gene (4 kb). Reverse transcription/polymerase chain reaction analysis allowed transcripts for the IL2R gamma (p64) gene to be detected in 3 of these melanoma cell lines (M14, IGR3, ME 1477). Incubation with human recombinant IL-2 modifies in IL-2R alpha+beta+gamma+ (M14) the expression of several surface molecules: down-regulation of ICAM-1, HLA class I and HLA-DR and up-regulation of CD44. IL-2 is also active on IL-2 alpha+beta+gamma- cell lines since it decreases ICAM-1 and HLA class-II expression at the surface of JUSO cells. Down-regulation of ICAM-1, whose expression in melanoma cells is a marker of tumor progression, is detectable within 3 hr in M14 cells and is maximal after 48 hr incubation, at IL-2 concentrations corresponding to the high-affinity heterodimers. This feature is specific since it is partially inhibited by MAbs directed against the IL-2 binding site of the IL-2R alpha (MAR93, 10T14) and IL-2R beta (MiK beta 1, TU27) chains. Our data support the notion of a direct effect of IL-2 on human melanoma cells. Modulation of the expression of surface molecules which is important for the interaction with immunocompetent cells or for tumor progression, could have a role to play during in vivo IL-2 treatment of human melanomas.
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PMID:Human melanoma cells express a functional interleukin-2 receptor. 834 47

The lack of HLA class I antigen expression by the melanoma cell line SK-MEL-33 is caused by a unique lesion in beta 2-microglobulin (beta 2-mu). Sequencing of beta 2-mu mRNA detected a guanosine deletion at position 323 in codon 76 that causes a frameshift with a subsequent introduction of a stop codon at a position 54 base upstream of the normal position of the stop codon in the message. The loss of 18 amino acids and the change of 6 amino acids, including a cysteine at position 80 in the carboxy terminus of beta 2-mu, are likely to cause marked changes in the structure of the polypeptide. The latter may account for the inability of beta 2-mu to associate with HLA class I heavy chains and for its lack of reactivity with the anti-beta 2-mu mAb tested. HLA class I antigen expression on SK-MEL-33 cells was reconstituted after transfection with a wild-type B2m gene, therefore indicating that the abnormality of endogenous B2m gene is the only mechanism underlying lack of HLA class I antigen expression by SK-MEL-33 cells. The guanosine deletion in B2m gene was detected also in the melanoma tissue from which SK-MEL-33 cells had originated. Therefore, the molecular lesion identified in the SK-MEL-33 melanoma cell line is not caused by a mutation acquired during growth in vitro but is likely to reflect a somatic mutation during tumor progression.
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PMID:Lack of HLA class I antigen expression by melanoma cells SK-MEL-33 caused by a reading frameshift in beta 2-microglobulin messenger RNA. 843 69

Immunohistochemical studies have shown that loss of HLA expression is observed in cervical carcinomas but not in premalignant CIN lesions, indicating that downregulation of HLA is linked to tumor progression. The present study was performed to investigate whether the degree of HLA expression in cervical cancer correlates with more advanced disease as defined by histopathological features. Frozen tissue sections from 49 patients with squamous carcinoma of the cervix FIGO stage IB to IIB were stained with HLA class I monomorphic, locus- and allele-specific monoclonal antibodies. Histological data indicative of local disease, i.e., depth of invasion, tumor size, stage, and systemic spread of the disease, such as tumor-positive lymph nodes, were collected by reviewing the histological slides. Univariate analysis revealed that loss of HLA-A locus and A2-allele expression showed a positive, significant correlation with both presence of tumor-positive lymph nodes (P = 0.04 and 0.02, respectively) and the number of lymph nodes involved (both P = 0.04). These results strongly support the idea that, specifically in an immunogenic cancer type such as cervical cancer, tumor cells escape immunosurveillance and gain growth advantage by allele-specific downregulation of the HLA-A2 molecule. In view of the development of immunotherapeutical interventions in cancer, upregulation of HLA class I molecules may prove to be a useful additional tool in the combat against immunogenic tumors.
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PMID:Association of allele-specific HLA expression and histopathologic progression of cervical carcinoma. 869 Feb 88

Human normal non hematopoietic cells of mesenchymal and neuroectodermal origin may express functional IL-Rs. For instance, in these cell types, IL-2 can stimulate proliferation (endothelial, intestinal and nervous cells) or modify the expression of adhesion molecules (fibroblasts) or inhibit proliferation (bone marrow stromal cells). Therefore, some cytotoxic effects described during IL-2 biotherapy could be due to a direct interaction between IL-2 and non-hematopoietic tissues. The expression of functional IL-2-R has also been reported in several human cell lines derived from solid tumors. In some instances IL-2 inhibits cell growth (head and neck, gastric and renal carcinomas), but in other tumors, growth stimulation and increased expression of markers of tumor progression have been reported (intestinal, breast, and lung carcinomas, gliomas, fibrosarcomas and melanomas). Additionally, secretion of biologically active IL-2 has been reported in some melanoma and breast cancer cell lines. Transcripts for the novel cytokine IL-15, which utilizes the beta and gamma chains of the IL2-R, have been found in melanoma cells and anti-IL-15 mAbs inhibit HLA class I expression in these cells. Therefore these cytokines may modify, inside a tumor, the behavior of both stromal and neoplastic cells. All these data may have important implications in our understanding of tumor host interactions and in future strategies of immunotherapy.
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PMID:Are interleukin-2 and interleukin-15 tumor promoting factors for human non-hematopoietic cells? 870 93

The number of HLA class I molecules and the susceptibility to lysis mediated by natural killer (NK) cells were evaluated on cell targets obtained from confluent and sparsely plated cultures of both normal and tumor cell lines. Sparsely plated proliferating cells expressed high amounts of HLA class I molecules and were more resistant to NK cell-mediated lysis than confluent cells, which expressed low amounts of HLA class I antigens. This characteristic could be involved in the control of cancer progression and could also explain the wide variability of assays of lymphocyte-mediated cytotoxic activity.
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PMID:Adherent neoplastic cells grown at confluence downregulate HLA class I expression and enhance their susceptibility to lysis mediated by natural killer cells. 938 19


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