Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:5.99.1.2 (topoisomerase)
 9,166 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of molecular markers predicting the response to cytotoxic chemotherapy is not established. A potential predictive factor, topoisomerase IIalpha, is a target for certain cytotoxic drugs, and its concentration has been shown to correlate with chemosensitivity in vitro. We evaluated expression of topo IIalpha immunohistochemically in 230 breast cancer samples and studied its association with known clinicopathological factors and factors previously shown to predict response to cytotoxic drugs. Topo IIalpha protein expression was found in 0.6 to 39.4% (10.6 +/- 7.9%, mean +/- SD) of breast carcinoma cells, whereas expression was undetectable in nonmalignant breast epithelium. Topo IIalpha protein expression correlated well with semi-quantitative mRNA in situ hybridization (P = 0.007). A significant association was found between the proportion of topo-IIalpha-positive cells and low estrogen and progesterone receptor content (P<0.0001), high grade (P<0.0001), DNA aneuploidy (P=0.003), and c-erbB-2 oncoprotein overexpression (P<0.0001). Topo IIalpha expression was not associated with clinical variables, such as age of the patient, primary tumor size, or axillary nodal status. A highly significant linear correlation was found between topo IIalpha and tumor proliferation rate (S-phase fraction, r=0.46; P<0.0001). Because hormone receptors, grade, and ploidy are associated with tumor proliferation rate, topo IIalpha expression was adjusted for S-phase fraction to reveal the proliferation-independent clinopathological associations. According to the analysis of co-variance, only aneuploidy (P=0.0003) and c-erb-2 overexpression (P=0.01) were associated with proliferation-adjusted expression of topo IIalpha. In conclusion, the close association of Topo IIalpha with other potential predictive factors (tumor proliferation rate, c-erbB-2 oncoprotein) suggests that topo IIalpha, having a defined role as a target for cytotoxic drugs, may be a valuable predictor of response to chemotherapy.
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PMID:Expression of topoisomerase IIalpha is associated with rapid cell proliferation, aneuploidy, and c-erbB2 overexpression in breast cancer. 866 91

Expression of the tumor suppressor gene product p53 and the cyclin-dependent kinase inhibitor p21, which is transcriptionally activated by p53, was investigated and compared with patient survival in a retrospective longitudinal study of 202 cases of endometrial carcinoma. The median duration of follow-up was 4.3 years. P53 was observed immunohistochemically in 63 (31%) of the tumors and was found by univariate analysis to be related to reduced adjusted survival (p = 0.00028) and disease-free survival (p = 0.04). However, p53 expression was not found by multivariate analysis to be an independent prognostic factor when compared with FIGO stage, histologic grade, and proliferative activity, as determined by immunoreactivity for topoisomerase IIalpha with the antibody Ki-S1. Overexpression of p53 was related to histologic grade (p < 0.00001), proliferative activity (p = 0.0071), and inversely to progesterone receptor content (p = 0.042). Immunohistochemical identification of p21 was investigated in 95 cases and found to be positive in 19 (39%) of 49 tumors with p53 overexpression and in 13 (28%) of 46 tumors without p53 overexpression (p = 0.28). Expression of p21 is therefore not related to p53 expression, nor was it found to be related to proliferative activity. Strong expression of p21 was observed in tumors negative for progesterone receptors (p = 0.0028). P53 in endometrial carcinoma is not associated with induction of the cell cycle inhibitor p21, but is associated with an enhanced proliferative activity. The findings of multivariate analysis suggest that the prognostic significance of p53 is related mainly to cell proliferation.
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PMID:p53 protein in endometrial cancer is related to proliferative activity and prognosis but not to expression of p21 protein. 942 Oct 76

Although cytotoxic chemotherapy is widely used in advanced breast cancer, there are no powerful predictors for the therapy response. Because topoisomerase IIalpha (Topo IIalpha) is the molecular target for the anthracycline class of anti-cancer drugs, we compared the immunocytochemical assay of Topo IIalpha with other biomarkers in the prediction of clinical response to Topo II inhibitor chemotherapy. Fifty-five patients with advanced breast cancer were treated with a single cytotoxic drug, Topo II-inhibitor, epirubicin (30 mg m(-2) weekly up to 1000 mg m(-2)), as first line cytotoxic chemotherapy. Objective response to treatment was analysed according to UICC criteria. The predictive value of Topo IIalpha expression, c-erbB2 oncoprotein, p53 tumour-suppressor protein, oestrogen (ER) and progesterone receptor (PR), S-phase fraction and DNA ploidy were analysed from representative formalin-fixed paraffin-embedded primary tumour samples. The proportion of Topo IIalpha-positive cells (Topo IIalpha index) failed to predict response to epirubicin therapy. Mean Topo IIalpha scores in 29 responding patients were similar when compared with those with no change in disease progression (n = 13) and those with progressive disease (n = 13) (14.9% +/- 11.4% vs 15.5% +/- 7.6% vs 17.3% +/- 13.2%, not significant). Among the other biomarkers tested, overexpression of c-erbB2 oncoprotein and hormone receptor negativity were significantly associated with poor response. Response rate in patients with c-erbB2-overexpressing tumours was 32% compared with 65% in patients with no c-erbB2 overexpression (P = 0.0058). Accordingly, the response rate for ER-positive patients was 67% compared with 26% in ER-negative patients (P = 0.0021). Although both negative ER status and c-erbB2 overexpression are associated with high Topo IIalpha expression in breast cancer, step-wise logistic regression analysis showed that ER and c-erbB2 were associated with therapy response independent of Topo IIalpha expression. Histological grade, p53, DNA-ploidy, tumour proliferation rate (S-phase fraction), stage of the disease at diagnosis, age of the patient, previous anti-oestrogen therapy or site of metastasis did not predict the response to epirubicin therapy. In conclusion, despite extensive in vitro evidence, expression of Topo IIalpha is unlikely to predict the response to Topo II inhibitor chemotherapy in advanced breast cancer. Among the prognostic biomarkers, overexpression of c-erbB2 oncogene and negative ER may have predictive value in epirubicin therapy in patients with advanced breast cancer.
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PMID:Predictive value of topoisomerase IIalpha and other prognostic factors for epirubicin chemotherapy in advanced breast cancer. 964 44

To evaluate the prognostic relevance of Ki-67 and topoisomerase IIalpha expression in relation to tumor stage, grade, and hormone receptor content, 942 ductal infiltrating carcinomas of the breast were examined by means of the monoclonal antibodies Ki-S11 (Ki-67) and Ki-S4 (topoisomerase IIalpha). pS2, c-erbB2, and p53 were additionally considered as prognostic variables. The median follow-up time was 149 months. Eight-hundred-and-sixty-three tumors reacted with Ki-S11 and Ki-S4; the labeling indices of the two antigens were closely associated (r = 0.93). Both correlated positively with the tumor size, c-erbB2, and p53 expression, and negatively with patient age, hormone receptor content, and pS2 immunostaining. In the univariate analysis, Ki-S11 and Ki-S4 scores, nodal status, tumor size, tumor grade, and progesterone receptor content strongly predicted both overall and metastasis-free survival (p < 0.00001). Estrogen receptor status, p53, and c-erbB2 were of minor significance. Concerning overall survival, multivariate Cox regression analysis selected a Ki-S4 score >25% (p < 0.00001) next to the nodal status, and before tumor size, progesterone receptor content, and patient age. Independent predictors of the occurrence of distant metastases were nodal status, Ki-S4, tumor size, grade 1, and progesterone receptor negativity, in that order. The Ki-S11 score was of independent prognostic significance only if examined as a continuous variable. We conclude that topoisomerase IIalpha expression as assessed by monoclonal antibody Ki-S4 may add valuable information to current prognostic models for breast cancer. Its predictive value appears to be essentially related to the proliferative activity of tumor cells.
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PMID:Prognostic significance of Ki-67 and topoisomerase IIalpha expression in infiltrating ductal carcinoma of the breast. A multivariate analysis of 863 cases. 1047 80

The purpose of this retrospective study was to examine the prognostic value of expression of luminal epithelial antigen (LEA.135) for recurrence and overall survival of patients with primary invasive breast carcinoma by both univariate and multivariate analyses. The possible prognostic value of LEA.135 was also compared with some widely utilized prognostic biomarkers such as c-erbB 2, topoisomerase II.alpha (TPII.alpha), MIB 1, estrogen receptor (ER) and progesterone receptor (PR), as well as age of the patients and clinicopathologic parameters. The study was carried out by immunohistochemical methods on formalin-fixed/paraffin-embedded tissue sections in a series of 225 patients with median follow-up of 8.5 years. Prognostic significance of the biomarkers was determined by two-sided p value. In this series of patients, among the age and clinicopathologic parameters, only age, was significantly associated with a decreased overall survival (logrank p = 0.027). Among the prognostic biomarkers, TPII a expression at high (> 50% positive cells) or moderate (6-50% positive cells) level was associated with an increased rate of recurrence (logrank p < 0.001). However, the association of TPII.alpha expression with a decreased overall survival failed to reach a statistically significance. Expression of c-erbB 2 showed a trend of being associated with an increased probability of recurrence, but the association did not reach statistical significance. The remaining biomarkers were not associated with either the probability of recurrence or overall survival. LEA.135 expression was observed in 163 (72.4%) of the 225 patients. The patients with high (> 50% positive cells) or moderate (6-50% positive cells) level of LEA.135-positive cancer cells showed a significantly decreased probability of recurrence (logrank p < 0.001) and an increased overall survival (logrank p < 0.001) compared with those with LEA.135-negative cancer cells. The association remained significant by multivariate analysis for recurrence (likelihood ratio test p < 0.001) and overall survival (likelihood ratio test p < 0.001) when assessed with other prognostic parameters. Furthermore, the combination of LEA.135 with other prognostic biomarkers stratified four subgroups of patients with distinct clinical outcome. The subgroup of patients who were LEA.135+/TPII.alpha- showed the lowest probability of recurrence and the longest overall survival compared with those who were LEA.135-/TPII.alpha+ (logrank p < 0.001). Interestingly, the patients whose cancer cells were LEA.135+/TPII.alpha+, LEA.135+ MIB.1+ or LEA.135+/c-erbB 2+ experienced a decreased probability of recurrence and an increased overall survival compared with those with LEA.135-/TPII.alpha+, LEA.135- MIB.1+ or LEA.135-/c-erbB 2+ (logrank p < 0.001). The results demonstrated that LEA.135 is an independent and favorable prognostic biomarker for patients with primary invasive breast carcinoma, that the loss of LEA.135 expression is associated with aggressive phenotype of cancer cells during the breast cancer progression, and that its continued expression seems to override the adverse effects of expression of an oncogene or cell proliferation-associated molecules.
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PMID:LEA.135 expression: its comparison with other prognostic biomarkers for patients with primary breast carcinoma. 1092 56

Basal-like breast cancers are characterized by their unique expression profile, with the frequent loss of BRCA1, caused by such mechanisms as promoter methylation and the overexpression of high-mobility group proteins of the A type 1 or inhibitor of differentiation 4. Clinicopathologically, basal-like cancers are estrogen receptor-, progesterone receptor-, and human epidermal growth factor receptor type 2 (HER2)-negative; they are of high grade and have a poor prognosis. The fundamental similarity between BRCA1-mutated and basal-like cancers indicates that disruption of BRCA1 may be an essential common initial pathogenic event. Furthermore, p53 mutation and EGFR overexpression occur similarly in BRCA1-mutated and basal-like cancers; these shared alterations provide very important information for understanding not only the genetic and epigenetic carcinogenic pathways in these tumors but also therapeutic strategies. Despite the limited available clinical data about response to chemotherapy, anthracycline-based chemotherapy seems to be effective in a distinct subset of basal-like cancers. Both disrupted BRCA1 and overexpressed topoisomerase II-alpha possibly found in basal-like cancers are speculated to be associated with their increased sensitivity to anthracyclines. If these tumors respond to this chemotherapy, a favorable prognosis might be expected; however, in patients who do not respond, the prognosis is poor. Currently, the sensitivity of basal-like cancers to taxanes is not clear, but considering that these tumors have disrupted mitotic checkpoint function, a poor response may be suggested. On the basis of in vitro studies, BRCA1-disrupted basal-like cancers may be sensitive to DNA-damaging agents including platinum-based compounds, topoisomerase I and II inhibitors, and alkylating agents. In future, new therapeutic approaches for patients with basal-like cancers that are unlikely to respond to chemotherapy should focus on molecules that are involved in the pathogenic pathways of this disease.
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PMID:Basal-like subtype and BRCA1 dysfunction in breast cancers. 1894 49

Recently, aldehyde dehydrogenase (ALDH) 1 has been identified as a reliable marker for breast cancer stem cells. The aim of our study was to investigate the clinicopathological characteristics of breast cancers with ALDH1+ cancer stem cells. In addition, the distribution of ALDH1+ tumor cells was compared on a cell-by-cell basis with that of estrogen receptor (ER)+, Ki67+, or human epidermal growth factor receptor type 2 (HER2)+ tumor cells by means of double immunohistochemical staining. Immunohistochemical staining of ALDH1 was applied to 203 primary breast cancers, and the results were compared with various clinicopathological characteristics of breast cancers including tumor size, histological grade, lymph node metastases, lymphovascular invasion, ER, progesterone receptor, HER2, Ki67, and topoisomerase 2A as well as prognosis. Immunohistochemical double staining of ALDH1 and ER, Ki67, or HER2 was also carried out to investigate their distribution. Of the 203 breast cancers, 21 (10%) were found to be ALDH1+, and these cancers were significantly more likely to be ER- (P = 0.004), progesterone receptor- (P = 0.025), HER2+ (P = 0.001), Ki67+ (P < 0.001), and topoisomerase 2A+ tumors (P = 0.012). Immunohistochemical double staining studies showed that ALDH1+ tumor cells were more likely to be ER-, Ki67-, and HER2+ tumor cells. Patients with ALDH1 (score 3+) tumors showed a tendency (P = 0.056) toward a worse prognosis than did those with ALDH1- tumors. Breast cancers with ALDH1+ cancer stem cells posses biologically aggressive phenotypes that tend to have a poor prognosis, and ALDH1+ cancer stem cells are characterized by ER-, Ki67-, and HER2+.
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PMID:Stem cell marker aldehyde dehydrogenase 1-positive breast cancers are characterized by negative estrogen receptor, positive human epidermal growth factor receptor type 2, and high Ki67 expression. 1938 68

Gene-expression profiling classified breast cancer to intrinsic subtypes, including luminal A and B, HER2 positive, normal-breast-like, and basal-like tumors. Of these, basal-like tumors that express basal cytokeratins and that are negative for estrogen receptor alpha, progesterone receptor, and HER2 show the most aggressive phenotype with a poor prognosis. Analyses of clinical samples and basic research indicate that basal-like breast cancer is caused by deficiencies in the breast cancer susceptibility protein, BRCA1. Indeed, conditionally deleting BRCA1 from the mammary gland causes mice to develop basal-like cancers at high rates. One of the major functions of BRCA1 is DNA double-strand break (DSB) repair, and its failure to perform causes increased sensitivity of cells to DNA damage-inducing agents, such as PARP inhibitors, DNA cross-linkers, or topoisomerase inhibitors. Therefore, BRCA1 dysfunction could be a principal target for therapeutic application of basal-like breast cancer. Recently, significant progress has been made in understanding the BRCA1 cascade in response to DSBs, where ubiquitin polymer formation plays critical roles. Ubiquitination was indeed found to be an apparent early response of breast cancer to neoadjuvant treatment with epirubicin and cyclophosphamide. Deducing the role of BRCA1 ubiquitin E3 ligase activity in this pathway is a critical challenge to further clarify its functional mechanism. In individualized treatment of breast cancer, evaluation of the DNA repair capacity by the BRCA1 pathway may be an important issue when determining proper treatment of basal-like breast cancer.
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PMID:Contemplating chemosensitivity of basal-like breast cancer based on BRCA1 dysfunction. 1945 31

Micropapillary carcinomas (MPCs) can present as a rare histological special type of breast cancer; however, this histological type is more frequently found admixed with invasive ductal carcinomas of no special type (IDC-NSTs). We have previously demonstrated that pure MPCs constitute a distinct entity at the morphological and genetic levels. Here, we sought to determine whether mixed MPCs have genomic aberrations similar to those found in pure MPCs, and to investigate whether the distinct morphological components of MPCs harbour different genetic aberrations. Using high-resolution microarray comparative genomic hybridization (aCGH), we profiled a series of 10 MPCs of mixed histology and 20 IDC-NSTs matched for grade and oestrogen receptor (ER) status. In addition, we generated tissue microarrays containing a series of 24 pure and 40 mixed MPCs and performed immunohistochemical analysis with ER, progesterone receptor (PR), Ki-67, HER2, cytokeratin (CK) 5/6, CK14, CK17, EGFR, topoisomerase-IIalpha, cyclin D1, caveolin-1 and E-cadherin antibodies. In situ hybridization was employed to evaluate the prevalence of HER2, TOP2A, EGFR, CCND1, MYC and FGFR1 gene amplification. Our results demonstrate that mixed MPCs harbour similar patterns of genomic aberrations and phenotype (82.5% luminal and 17.5% HER2) compared to pure MPCs. A comparison between the distinct morphological components of mixed MPCs in a pairwise fashion revealed that both components harbour strikingly similar genomic profiles. When compared to grade- and ER-matched IDC-NSTs, mixed MPCs significantly more frequently harboured amplification of multiple regions on 8q (adjusted Fisher's p value < 0.05). Furthermore, mixed MPCs displayed higher proliferative rates than grade- and ER-matched IDC-NSTs. Our results suggest that micropapillary differentiation in breast cancer may identify a subgroup of more aggressive ER-positive breast carcinomas, even in those featuring a mixed histology, and that mixed MPCs are more closely related to pure MPCs than to IDC-NSTs.
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PMID:Mixed micropapillary-ductal carcinomas of the breast: a genomic and immunohistochemical analysis of morphologically distinct components. 1947 27

The CAN-NCIC-MA22 phase I/II clinical trial evaluated women with locally advanced or inflammatory breast cancer treated with epirubicin and docetaxel at 2 or 3 weekly intervals in sequential cohorts. The relationship between various biomarkers and treatment response was assessed. Breast biopsy cores were obtained from 50 patients pre-, mid-, and post-treatment. Immunohistochemical staining was performed to determine baseline levels of estrogen receptor (ER), progesterone receptor (PR), Her2/Neu protein (HER2), and topoisomerase II (Topo 2),expressed as percent positive stain. Tumor RNA integrity(RIN) and tumor cellularity were measured pre-, mid- and post-treatment by capillary electrophoresis and light microscopy after hematoxylin/eosin staining, respectively.Associations between 1) maximum RIN and 2) tumor cellularity at the three time points with baseline levels of ER,PR, Her2, and topo II were assessed using Spearman and Pearson correlation coefficients. Associations between RIN and tumor cellularity with chemotherapy dose level orpathologic response were assessed using one-way ANOVA.In this study, we observed that low mid-treatment maximum RIN (but not tumor cellularity) was associated with high chemotherapy drug dose level (P = 0.05) and eventual pathologic complete response (pCR) (P = 0.01). Posttreatment,low maximum RIN was found to be associated with low tumor cellularity (P = 0.004), and low tumor cellularity with pCR (P = 0.01). Post-treatment tumor cellularity was lowest in patients with tumors having high baseline PR levels (P = 0.05). The association of midtreatment RIN with drug dose level and with pCR suggests that tumor RIN may represent an important new biomarker for measuring response to chemotherapy in breast cancer patients.
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PMID:Association of low tumor RNA integrity with response to chemotherapy in breast cancer patients. 1977 8


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