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Query: UMLS:C0178874 (
tumor progression
)
40,807
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
To investigate the molecular mechanism of gastric carcinogenesis, we examined simultaneously the frequency of microsatellite instability and the immunoreactivities to ras,
erbB-2
, and p53 in 42 gastric adenocarcinoma tissues. Microsatellite instability, measured by DNA replication error, was detected in 33.3% (14/42) of patients with gastric carcinoma while positive immunostaining was demonstrated in 3.1% (1/32) for ras, 40.5% (17/42) for
erbB-2
, and 28.6% (12/42) for p53. There was no statistical difference between the intestinal type and the diffuse type of carcinoma with respect to microsatellite instability, ras, or
erbB-2
expression. The expression of p53 occurred more frequently in the intestinal type of carcinoma (41.7%, 10/24) than in the diffuse type of carcinoma (11.1%, 2/18; P < 0.01). There was no association between microsatellite instability and ras or p53 expression, while enhanced expression of
erbB-2
occurred more frequently in carcinomas with microsatellite instability (64.3%, 9/14) than in those without microsatellite instability (28.6%, 8/28; P < 0.05). Such a strong association between microsatellite instability and
erbB-2
oncogene may be responsible for the increase of other oncogenic mutations and
tumor progression
in gastric carcinogenesis.
...
PMID:Occurrence of microsatellite instability in gastric carcinoma is associated with enhanced expression of erbB-2 oncoprotein. 788 46
Metastatic phenotype in human solid tumors is believed to follow stochastic acquisition of structural genetic aberrations-so-called multistep
tumor progression
. We tested this hypothesis in breast carcinoma by immunostaining 89 stage-heterogeneous cases for the products of three genes (p53,
ERBB-2
, and EGFR) which are frequently altered in this tumor system. Variable relationships were observed between advanced disease stage and immunostaining for individual gene products (
ERBB-2
- p = 0.05, EGFR - p = 0.02, p53 - p = 0.12, Chi Square test). Regional or distant metastases at presentation correlated with multiple oncogene/tumor suppressor gene expression abnormalities: node negative -59% none positive, 29% one positive, 12% two or more positive, vs. node positive -37% none positive, 23% one positive, 39% two or more positive (p = 0.01). Only 2/12 (17%) of tumors with distant metastases at presentation were negative for abnormal expression of any of these gene products, and 7/12 (58%) were positive for two or three. Among axillary node negative patients who developed recurrences, 67% exhibited staining for at least one gene product, compared to only 27% of those without recurrences (p = 0.02). All 5 cases with abnormal staining for each gene product had regional or distant metastases at presentation and recurred. In multivariate analysis, individual expression of p53 outweighed expression of
ERBB-2
and EGFR in correlation with outcome. These data suggest clinical
neoplastic progression
of breast carcinomas correlates with cumulative genetic events detectable by protein expression. Short term recurrence, however, may correlate more closely with abnormal expression of p53 than with EGFR or
ERBB-2
.
...
PMID:Concurrent abnormal expression of ERBB-2, EGFR, and p53 genes and clinical disease progression of breast carcinoma. 791 62
Tumor proliferation in bladder cancer is associated with tumor behavior. To assess the association between Ki-67 labeling index (LI), p53, and c-
erbB-2
overexpression, formalin-fixed tissue samples of 160 patients with transitional cell carcinoma (TCC) of the urinary bladder were studied by immunohistochemistry. Ki-67 LI was strongly associated with tumor stage (P < .0001), tumor grade (P < .0001), and p53 status (P = .0014) but not with
erbB-2
overexpression (P > .2). Ki-67 LI was higher in p53-positive tumors (19%) than in p53-negative tumors (14%) when all stages were compared. Ki-67 LI was independent of p53 expression in pTa tumors (p53-positive, 9%; p53-negative, 11%), showing that p53 overexpression alone is not sufficient to induce rapid tumor cell proliferation in pTa tumors. Ki-67 LI also was independent of p53 expression in pT2 to pT4 tumors (p53-positive, 20%; p53-negative, 23%), indicating that p53 expression is not necessary for rapid tumor cell proliferation in advanced stages. However, there was a striking difference in Ki-67 LI between p53-positive pT1 tumors (22.0% +/- 8.8 standard deviation [SD]; n = 20) and p53-negative pT1 tumors (9.7 +/- 8.3 SD; n = 22; P = .0001). These results suggest that increased proliferation in p53-positive pT1 tumors is caused by additional alterations that occur during
tumor progression
.
...
PMID:p53 but not erbB-2 expression is associated with rapid tumor proliferation in urinary bladder cancer. 800 30
Perturbations of oncogenes in breast carcinoma include amplifications of the
HER-2/neu
and PRAD1 genes, as well as p53 mutations. Some of these lesions frequently appear in early cancers such as ductal carcinoma in situ and are stable as the tumors become invasive and metastasize. Thus these findings suggest that oncogene mutations may define a point of origin for a given breast cancer, and are fixed lesions during
tumor progression
. Such germline abnormalities may occur at the BRCA1, H-RAS VNTR, and p53 loci. The rational use of genetics may be to identify women at high risk for the development of breast cancer so that they may be enrolled in future chemoprevention trials.
...
PMID:Oncogenes, breast cancer, and chemoprevention. 800 94
The immunohistochemical expression of the p53 gene protein was examined in a consecutive series of 143 cases of pure ductal carcinoma in situ (DCIS) of the breast. Expression of wild-type and/or mutant p53 protein was detected in 36 (25.2%) of the cases examined, as evidenced by positive nuclear staining with the monoclonal antibody DO 7. Thirty-four (35.8%) of the large cell cases showed p53 protein expression compared with two (4.1%) of the small cell cases (chi 2 = 15.3 [df = 1], P < .001). p53 Protein expression also was associated with an increased histologic degree of necrosis, with a nearly significant association of negative tumor estrogen receptor status and p53 protein expression. No significant association of p53 protein expression and c-
erbB-2
protein expression was seen. Immunohistochemical expression of p53 protein is present in approximately 25% of DCIS cases and is confined almost exclusively to large cell DCIS, a morphologic subtype of in situ breast carcinoma thought to be more biologically aggressive. Expression of p53 protein may be important in the
neoplastic progression
of DCIS, reflecting the acquisition of p53 gene mutations in large cell DCIS cases. Therefore, p53 may be implicated in mammary tumor evolution from in situ to invasive disease.
...
PMID:p53 protein expression in mammary ductal carcinoma in situ: relationship to immunohistochemical expression of estrogen receptor and c-erbB-2 protein. 809 18
To study the relationship of tumor genomic heterogeneity with bladder cancer phenotype and p53 gene alterations, 138 primary bladder tumors were examined by dual labeling fluorescence in situ hybridization (FISH) using probes for chromosome 17 centromere (p17H8) and p53 (17p13.1). The number of different aneusomic populations > 5% (and monosomic populations > 20%) of cells served as a marker for heterogeneity. Nuclear p53 overexpression and Ki67 labeling index (Ki67 LI) were determined by immunohistochemistry. The number of aneusomic populations was 0 in 53 tumors, 1 in 18, 2 in 47, 3 in 9, and > 3 in 11 tumors. Presence of aneusomy was associated with tumor grade and stage (P < 0.0001 each). Ki67 LI was low in disomic tumors (11.0 +/- 7.7), higher in tumors with 1-3 aneusomic populations (17.4 +/- 11.3), and highest in tumors with > 3 aneusomic populations (25.8 +/- 10.9; P = 0.02 for > 3 vs. 1-3 populations). Aneusomy and heterogeneity were associated with p53 alterations. Aneusomy was seen in 35% of tumors with neither p53 expression nor p53 deletion but in 97% of tumors with both p53 deletion and expression. Nine of 11 tumors with > 3 aneusomic populations exhibited both p53 deletion and overexpression. To study genomic heterogeneity in
tumor progression
, two recurrences and three metastases of a tumor with known
erbB-2
amplification were examined for centromere 17 and
erbB-2
copy number. A considerable heterogeneity in centromere 17 and
erbB-2
gene copy number was found in both recurrences and metastases, indicating a marked genomic instability in these metastatic cells.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Heterogeneity of chromosome 17 and erbB-2 gene copy number in primary and metastatic bladder cancer. 852 69
The occurrence of different components of the cell growth regulation pathway as expressed in experimental skin carcinogenesis in haired carcinogen-sensitive NMRI, in haired carcinogen resistant DBA/2 mice and in hairless SKH/1 mice was studied by morphological and immunohistochemical methods. The results were compared with respect to neoplastic response, number of tumors, tumor behaviour and to the inducing agent (UV irradiation or chemical carcinogen), in order to increase our understanding of specific alterations in neoplastic development caused by extraneous agents and to determine their possible usefulness as indicators of carcinogen exposure. The expression of growth factors (transforming growth factor alpha and epidermal growth factor), growth factor receptors (epidermal growth factor receptor/c-erbB-1 and c-
erbB-2
/neu), cell signalling component c-myc, the nuclear transcription factor Harvey-Ras and the tumor suppressor gene p53, were studied in carcinogen- and UV-induced tumor formation in mouse. The results showed increased oncogene expression as well as growth factor expression in the skin during tumor development appearing early in neoplastic and premalignant conditions and becoming more distinct during
neoplastic progression
. Efforts to delineate specifically initiated cells prior to the appearance of morphologically detectable alterations including dysplasia, papilloma formation and squamous cell carcinomas, were unsuccessful. Increased staining by antibodies to growth factors and oncogenes were also observed in DBA/2 animals resistant to tumor formation. It is concluded that oncogene expression and growth factor protein deposits are associated with carcinogenic effects, partly explaining the mechanism of action of these agents, but the applicability, as such, for the analysis of potential hazardous agents needs further studies.
...
PMID:Oncogenes and growth factors as indicators of carcinogen exposure. 867 68
The
erbB-2
receptor plays an important role in the prognosis of breast cancer. Amplification or overexpression of the
erbB-2
proto-oncogene has been detected in 30% of breast cancers and is associated with poor patient prognosis. The significance of erbB-3 and erbB-4 in breast cancer is not yet known. The discovery of the growth factor heregulin (HRG) has allowed us to investigate a number of biological events that are regulated by
erbB-2
, -3, and -4 signal transduction. To determine the role of HRG in breast cancer
tumor progression
, we have developed an in vitro/in vivo model. We transfected HRG cDNA into the estrogen receptor (ER)-positive breast cancer cell line, MCF-7, and studied these cells as they progressed from a hormone-dependent to -independent phenotype. The biochemical and biological characteristics presented here demonstrate that overexpression of HRG induces morphological changes in MCF-7 cells as well as
erbB-2
, erbB-3, and erbB-4 autophosphorylation. MCF-7/ heregulin-transfected cells, which express relatively high levels of HRG, developed estrogen independence and resistance to antiestrogens in vitro and in vivo. This is consistent with a more aggressive hormone-independent phenotype. In contrast with control parental/wild-type cells, estradiol-mediated down-regulation of
erbB-2
expression is blocked completely in this particular model system. These results indicate that HRG plays a role in the disruption of ER function. When a transient transfection with an ERE-CAT construct was introduced into these HRG-transfected MCF-7 cells, we observed that the ER was transcriptionally inactive. This suggests that ER signaling is altered in HRG-transfected cells. We observed that overexpression of HRG induces a more aggressive, hormone-independent phenotype that is most likely directly related to the constitutive activation of the
erbB-2
, erbB-3, and erbB-4 receptor signaling cascade. The data presented here suggest a close cross-regulation between the
erbB-2
/4 receptors and ER and provide new insights into the mechanism by which breast cancer cells acquire a hormone-independent phenotype.
...
PMID:Involvement of heregulin-beta2 in the acquisition of the hormone-independent phenotype of breast cancer cells. 876 33
The
erbB-2
receptor plays an important role in the prognosis of breast cancer and is expressed at high levels in nearly 30% of tumors in breast cancer patients. While evidence accumulates to support the relationship between
erbB-2
overexpression and poor overall survival in human breast cancer, understanding of the biological consequence(s) of
erbB-2
overexpression remains elusive. The discovery of heregulin has allowed us to identify a number of related but distinct biological endpoints which appear responsive to signal transduction through the
erbB-2
/4 receptor. These endpoints of growth, invasiveness, and differentiation have clear implications for the emergence, maintenance, and/or control of malignancy, and represent established endpoints in the assessment of malignant progression in human breast cancer. Preliminary studies in vitro have shown that heregulin induces a biphasic growth effect on cells with
erbB-2
overexpression. Interestingly, we observed that expression of heregulin correlates with a more aggressive/invasive, vimentin-positive phenotype in breast cancer cells lines. Therefore, we have postulated that heregulin is involved in breast cancer
tumor progression
. We have shown that heregulin induces in vitro chemoinvasion and chemotaxis of breast cancer cells as well as growth in an anchorage dependent and independent manner. Interestingly, a heregulin neutralizing antibody inhibits chemotaxis and results in cell growth inhibition and blockade of the invasive phenotype. Strikingly, genetically engineered cells which constitutively express heregulin demonstrate critical phenotypic changes that are associated with a more aggressive phenotype. Specifically, these cells are no longer dependent on estrogen for growth and are resistant to tamoxifen in vitro and in vivo, and moreover these cells metastasize to lymph nodes in athymic nude mice. These tumors appear to have lost bcl-2 expression as compared with the control tumors. In addition, presumably by activation/regulation of topoisomerase II, the heregulin-transfected cells become exquisitely sensitive to doxorubicin and VP-16. Clearly, mechanistic aspects of the
erbB-2
/4 and heregulin interaction need to be understood from a therapeutic standpoint which could provide additional insights into synergistic treatments for certain patients, or improve treatment regimens for a large number of women. The study of heregulin and its co-expression with
erbB-2
/4 receptor and the assessment of its involvement in the progression from the in situ stage of breast tumors to the invasive one will additionally increase the relevance of heregulin as a prognostic/diagnostic factor. We believe that our studies provide new insights into breast cancer diagnosis, prognosis, and treatment.
...
PMID:The significance of heregulin in breast cancer tumor progression and drug resistance. 882 23
Apoptosis or programmed cell death represents a mechanism by which tumor cells with DNA damage can be deleted. Bcl-2 and p53 gene products have both been linked to apoptosis. Bcl-2 plays a role as an inhibitor of apoptosis that may extend the viability of cells containing genetic alterations and facilitate
tumor progression
. Mutant p53 has a similar effect. The purpose of this study was to investigate the relationship between bcl-2 and p53 expression and to clarify their roles in apoptosis in different histological graded breast carcinomas. We analysed 101 invasive ductal carcinomas of the breast for the expression of bcl-2, p53, c-
erbB-2
, estrogen and progesterone receptors using immunohistochemistry. Reciprocal expression of bcl-2 and p53 was present in 71.3% of cases. The bcl-2+/p53-expression pattern was prevalent in histological grade I and II tumors (77.4% and 59.3% respectively) and rarely present in histological grade III (6.3%). Conversely, bcl-2-/p53+ expression pattern was rarely present in histological grade I and II tumors (3.2% and 11.1% respectively) and prevalent in histological grade III (50.0%). Our results also showed that Bcl-2 expression was positively correlated with ER and PR, more prevalent in pre-menopausal status, and negatively correlated with cerbB-2 expression. Bcl-2 expression was involved in
tumor progression
in well-differentiated tumors and mutant p53 could substitute for bcl-2 function in poorly differentiated tumors. The bcl-2/p53 expression pattern of tumors may be of value in predicting therapeutic response and prognosis. Bcl-2 expression was correlated with other well-established prognostic factors and bcl-2 could be an estrogen-related protein.
...
PMID:Reciprocal expression of Bcl-2 and p53 in breast ductal carcinoma. 891 21
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