Human DNA topoisomerase II-alpha: a new marker of cell proliferation in invasive breast cancer

Drug Repurposing: A Leading Strategy for New Threats and Targets

Less than 6% of rare illnesses have an appropriate treatment option. Repurposed medications for new indications are a cost-effective and time-saving strategy that results in excellent success rates, which may significantly lower the risk associated with therapeutic development for rare illnesses. It is becoming a realistic alternative to repurposing "conventional" medications to treat joint and rare diseases considering the significant failure rates, high expenses, and sluggish stride of innovative medication advancement. This is due to delisted compounds, cheaper research fees, and faster development time frames. Repurposed drug competitors have been developed using strategic decisions based on data analysis, interpretation, and investigational approaches, but technical and regulatory restrictions must also be considered. Combining experimental and computational methodologies generates innovative new medicinal applications. It is a one-of-a-kind strategy for repurposing human-safe pharmaceuticals to treat uncommon and difficult-to-treat ailments. It is a very effective method for discovering and creating novel medications. Several pharmaceutical firms have developed novel therapies by repositioning old medications. Repurposing drugs is practical, cost-effective, and speedy and generally involves lower risks when compared to developing a new drug from the beginning.

Topoisomerase IIα immunoexpression in feline mammary carcinomas: A correlation with Ki67 immunoexpression and the mitotic count

The aim of the study was to compare the immunohistochemical expression of topoisomerase IIα protein (Topo IIα) with Ki67 expression and mitotic count in feline mammary carcinomas (FMCs). Topo IIα is considered as a proliferation indicator as well as a molecular target of anthracycline chemotherapy. The studied material included 70 FMCs from female cats treated with mastectomy. Primary mouse monoclonal antibodies directed against Topo IIα and Ki67 were used in immunohistochemical reactions. The number of mitotic figures was counted at 400× magnification in a field of 2.37 mm2. Immunohistochemical reaction for Topo IIα occurred in cell nuclei. The Topo IIα index ranged from 6.12% to 54.60% and was positively correlated with the values of the Ki67 index (r = 0.7193) and the mitotic count (r = 0. 2858). This indicates the potential possibility of use of the immunohistochemical expression of Topo IIα to assess the rate of proliferation in FMCs. The wide range of expression of Topo IIα in individual tumorus found in the conducted studies allows us to hypothesize that its assessment could be used as a predictive marker in chemotherapy of FMCs with the use of anthracyclines. However, this requires confirmation in clinical trials.

Effects of In Vitro Digestion of Polyphenols from Coffee on Binding Parameters to Human Topoisomerase II α

Type II topoisomerase (TOPII) is an enzyme that influences the topology of DNA. DNA breaks generated by TOPII may result in mutagenic or cytotoxic changes in cancer cells. In this study, we characterized interactions of TOPIIα with coffee extracts and individual chlorogenic acids (CHAs) from the extracts by performing isothermal titration calorimetry (ITC) and molecular docking (MD) simulations. The study showed that the highest affinity to TOPIIα was found in green coffee (ΔG = -38.23 kJ/mol) and monochlorogenic acids fraction of coffee extracts (ΔG = -35.80 kJ/mol), resulting from the high content of polyphenols, such as CHAs, which can bind to the enzyme in the active site. Coffee extracts and their fractions maintained a high affinity for TOPIIα after simulated digestion in the presence of probiotic bacteria. It can be concluded that coffee may be a potential TOPIIα inhibitor considered as a functional food for cancer prevention.

A monoadduct generating Ru(ii) complex induces ribosome biogenesis stress and is a molecular mimic of phenanthriplatin

Ruthenium complexes are often investigated as potential replacements for platinum-based chemotherapeutics in hopes of identifying systems with improved tolerability in vivo and reduced susceptibility to cellular resistance mechanisms. Inspired by phenanthriplatin, a non-traditional platinum agent that contains only one labile ligand, monofunctional ruthenium polypyridyl agents have been developed, but until now, few demonstrated promising anticancer activity. Here we introduce a potent new scaffold, based on [Ru(tpy)(dip)Cl]Cl (tpy = 2,2':6',2''-terpyridine and dip = 4,7-diphenyl-1,10-phenanthroline) in pursuit of effective Ru(ii)-based monofunctional agents. Notably, the extension of the terpyridine at the 4' position with an aromatic ring resulted in a molecule that was cytotoxic in several cancer cell lines with sub-micromolar IC50 values, induced ribosome biogenesis stress, and exhibited minimal zebrafish embryo toxicity. This study demonstrates the successful design of a Ru(ii) agent that mimics many of the biological effects and phenotypes seen with phenanthriplatin, despite numerous differences in both the ligands and metal center structure.

Thiosemicarbazide Derivatives Targeting Human TopoIIα and IDO-1 as Small-Molecule Drug Candidates for Breast Cancer Treatment

In 2020, breast cancer became the most frequently diagnosed type of cancer, with nearly 2.3 million new cases diagnosed. However, with early diagnosis and proper treatment, breast cancer has a good prognosis. Here, we investigated the effect of thiosemicarbazide derivatives, previously identified as dual inhibitors targeting topoisomerase IIα and indoleamine-2,3-dioxygenase 1 (IDO 1), on two distinct types of breast cancer cells (MCF-7 and MDA-MB-231). The investigated compounds (1-3) selectively suppressed the growth of breast cancer cells and promoted apoptosis via caspase-8- and caspase-9-related pathways. Moreover, these compounds caused S-phase cell cycle arrest and dose-dependently inhibited the activity of ATP-binding cassette transporters (MDR1, MRP1/2 and BCRP) in MCF-7 and MDA-MB-231 cells. Additionally, following incubation with compound 1, an increased number of autophagic cells within both types of the investigated breast cancer cells was observed. During preliminary testing of ADME-Tox properties, the possible hemolytic activities of compounds 1-3 and their effects on specific cytochrome P450 enzymes were evaluated.

Prognostic Value and Significant Pathway Exploration Associated with TOP2A Involved in Papillary Thyroid Cancer

Background

Topoisomerase 2-alpha (TOP2A) has been identified as a hub gene that played an important role in the initiation and progression of thyroid carcinoma (THCA). However, the exact function of TOP2A in papillary thyroid cancer (PTC) remained elusive. The current study aimed to evaluate the TOP2A expression, prognosis significance and key signaling pathways involved in PTC.

Methods

We firstly evaluated the expression of TOP2A in PTC via UALCAN, cBioportal, HPA and LinkdedOmics databases. Genetic alteration of TOP2A in PTC was then explored in cBioportal. Prognostic impacts of TOP2A expression on disease-free survival (DFS) of PTC patients were subsequently evaluated using Kaplan–Meier plotter and Gepia databases. Taking gender, age, cancer stage, T, N and M stages into consideration, we compared survival difference between TOP2A high and low expression groups. KEGG pathway analysis in WebGestalt and GSEA analysis were further performed to reveal the potential TOP2A-associated signaling pathways involved in PTC. Finally, the upstream microRNAs of TOP2A were assessed using DIANA, TargetScan, miRDB and miRWALK database, followed by mechanism exploration of upstream microRNAs.

Results

1) The mRNA and protein of TOP2A were highly expressed in PTC tissue compared with normal thyroid tissue. TOP2A expression was associated with patient’s age, N stage and cancer stage (all P<0.05). TOP2A protein was mainly localized to nucleoplasm. 2) Most of samples occurred the missense substitution, and mutation site was located at K1199E. Nucleotide mutations were mainly presented as G>A (35.29%). 3) TOP2A high expression significantly influenced the DFS of PTC patients (P=0.015). Restricted survival analysis showed that TOP2A high expression caused poorer DFS of female patients (P=0.003) and those with age <60 years old (P=0.002), early clinical stage (P=0.012), N0 stage (P=0.002) or M0 stage (P=0.040). 4) Pathway analysis suggested that TOP2A positively participated in the cell cycle, oocyte meiosis and p53 signaling pathways (all P<0.05) involved in thyroid cancer.

Conclusion

The expression of TOP2A was higher in PTC tissue, which resulted in a worse DFS of patients with PTC. TOP2A might act as an effective therapeutic target for PTC treatment.

A new computational drug repurposing method using established disease-drug pair knowledge

MOTIVATION

Drug repurposing is a potential alternative to the classical drug discovery pipeline. Repurposing involves finding novel indications for already approved drugs. In this work, we present a novel machine learning-based method for drug repurposing. This method explores the anti-similarity between drugs and a disease to uncover new uses for the drugs. More specifically, our proposed method takes into account three sources of information: (i) large-scale gene expression profiles corresponding to human cell lines treated with small molecules, (ii) gene expression profile of a human disease and (iii) the known relationship between Food and Drug Administration (FDA)-approved drugs and diseases. Using these data, our proposed method learns a similarity metric through a supervised machine learning-based algorithm such that a disease and its associated FDA-approved drugs have smaller distance than the other disease-drug pairs.

RESULTS

We validated our framework by showing that the proposed method incorporating distance metric learning technique can retrieve FDA-approved drugs for their approved indications. Once validated, we used our approach to identify a few strong candidates for repurposing.

AVAILABILITY AND IMPLEMENTATION

The R scripts are available on demand from the authors.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Prognostic value of TOP2A in bladder urothelial carcinoma and potential molecular mechanisms

BACKGROUND

The prognosis of bladder urothelial carcinoma (BLCA) varies greatly among patients, and conventional pathological predictors are generally inadequate and often inaccurate to predict the heterogeneous behavior of BLCA. This study aims to investigate the prognostic value and function of TOP2A in BLCA.

METHODS

TOP2A expression level was examined by RNA-sequencing, quantitative real time polymerase chain reaction and immunohistochemistry from 10, 40 and 209 BLCA samples, respectively. Public databases were analyzed for validation. Cell proliferation, migration, invasion assays were performed to explore potential functions of TOP2A in BLCA. Flow cytometry was performed for cell cycle and apoptosis analysis. Univariable and multivariable Cox regression models were performed to identify independent risk factors for the prognosis of BLCA.

RESULTS

We found TOP2A was significantly upregulated in BLCA samples, especially for high-grade and advanced stage tumors, compared with matched normal epithelial tissue. Univariable COX regression analysis revealed high TOP2A expression was significantly associated with poorer cancer-specific, progression-free and recurrence-free survival, but not independently of clinical characteristics in the multivariable models. Knockdown of TOP2A remarkably inhibited the proliferation of BLCA cells and non-cancerous urothelial cells. Furthermore, migration and invasion capacity of BLCA cells were strongly suppressed after TOP2A knockdown. Moreover, flow cytometry suggested TOP2A had anti-apoptotic function, and knockdown of TOP2A could induce resistance to doxorubicin in J82 cells.

CONCLUSIONS

In our study, TOP2A was overexpressed in BLCA and could serve as a prognostic biomarker for BLCA. Moreover, TOP2A is functionally important for the proliferation, invasion and survival of BLCA cells.

Role of Endothelium in Doxorubicin-Induced Cardiomyopathy

The clinical use of doxorubicin in cancer is limited by cardiotoxic effects that can lead to heart failure. Whereas earlier work focused on the direct impact of doxorubicin on cardiomyocytes, recent studies have turned to the endothelium, because doxorubicin-damaged endothelial cells can trigger the development and progression of cardiomyopathy by decreasing the release and activity of key endothelial factors and inducing endothelial cell death. Thus, the endothelium represents a novel target for improving the detection, management, and prevention of doxorubicin-induced cardiomyopathy.

Overexpression of topoisomerase II alpha protein is a factor for poor prognosis in patients with luminal B breast cancer

Background

The prognostic value and the best method of testing of topoisomerase II alpha (TOP2A) status have not been established in modern tailored therapy based on breast cancer subtype.

Results

The frequencies of TOP2A overexpression and TOP2A amplified were 55.8% and 9.5%, respectively. TOP2A overexpression correlated strongly with non-luminal A subtype (χ²-test, p < 0.001). TOP2A overexpression was significantly associated with relapse-free survival in luminal B breast cancer (n = 316; log rank test, p < 0.001) but not in other breast cancer subtypes. Cox regression analysis showed that TOP2A overexpression is a significant prognostic factor in luminal B breast cancer (hazard ratio (HR) 4.00, 95% confidence interval (CI) 1.65–9.54, p = 0.002). TOP2A amplified was recognized in HER2 positive breast cancer (p < 0.001). In HER2 positive breast cancer, TOP2A amplified (HR 0.30, 95% CI 0.085–1.07, p = 0.063) appeared to be a better prognostic factor.

Conclusion

In modern tailored therapy, TOP2A overexpression can be a poor prognostic factor in luminal B breast cancer. In contrast, TOP2A amplified could be a better prognostic factor in HER2 positive breast cancer.

Materials and methods

Between May 2005 and April 2015, a total of 643 consecutive non-metastatic invasive breast cancers were evaluated for TOP2A amplified using fluorescence in situ hybridization analysis (FISH) and for TOP2A overexpression using the immunohistochemistry assay. FISH ratios of 2 or higher were designated as TOP2A amplified, and TOP2A staining >10% was defined as TOP2A overexpression. The prognostic values of TOP2A amplified and TOP2A overexpression were retrospectively evaluated.

Network pharmacology-based and clinically relevant prediction of the active ingredients and potential targets of Chinese herbs in metastatic breast cancer patients

Chinese Herbal Medicine (CHM) plays a significant role in breast cancer treatment. We conduct the study to ascertain the relative molecular targets of effective Chinese herbs in treating stage IV breast cancer.Survival benefit of CHM was verified by Kaplan-Meier method and Cox regression analysis. A bivariate correlation analysis was used to find and establish the effect of herbs in complex CHM formulas. A network pharmacological approach was adopted to explore the potential mechanisms of CHM.Patients in the CHM group had a median survival time of 55 months, which was longer than the 23 months of patients in the non-CHM group. Cox regression analysis indicated that CHM was an independent protective factor. Correlation analysis showed that 10 herbs were strongly correlated with favorable survival outcomes (P<0.01). Bioinformatics analyses suggested that the 10 herbs might achieve anti-breast cancer activity primarily through inhibiting HSP90, ERα and TOP-II related pathways.

Functional Relationship and Gene Ontology Classification of Breast Cancer Biomarkers

Breast cancer is a complex disease that still imposes a significant healthcare burden on women worldwide. The etiology of breast cancer is not known but significant advances have been made in the area of early detection and treatment. The advent of advanced molecular biology techniques, mapping of the human genome and availability of high throughput genomic and proteomic strategies opens up new opportunities and will potentially lead to the discovery of novel biomarkers for early detection and prognostication of breast cancer. Currently, many biomarkers, particularly the hormonal and epidermal growth factor receptors, are being utilized for breast cancer prognosis. Unfortunately, none of the biomarkers in use have sufficient diagnostic, prognostic and/or predictive power across all categories and stages of breast cancer. It is recognized that more useful information can be generated if tumors are interrogated with multiple markers. But choosing the right combination of biomarkers is challenging, because 1) multiple pathways are involved, 2) up to 62 genes and their protein products are potentially involved in breast cancer-related mechanisms and 3) the more markers evaluated, the more the time and cost involved. This review summarizes the current literature on selected biomarkers for breast cancer, discusses the functional relationships, and groups the selected genes based on a Gene Ontology™ classification.

Interlinked DNA nano-circles for measuring topoisomerase II activity at the level of single decatenation events

DNA nano-structures present appealing new means for monitoring different molecules. Here, we demonstrate the assembly and utilization of a surface-attached double-stranded DNA catenane composed of two intact interlinked DNA nano-circles for specific and sensitive measurements of the life essential topoisomerase II (Topo II) enzyme activity. Topo II activity was detected via the numeric release of DNA nano-circles, which were visualized at the single-molecule level in a fluorescence microscope upon isothermal amplification and fluorescence labeling. The transition of each enzymatic reaction to a micrometer sized labeled product enabled quantitative detection of Topo II activity at the single decatenation event level rendering activity measurements in extracts from as few as five cells possible. Topo II activity is a suggested predictive marker in cancer therapy and, consequently, the described highly sensitive monitoring of Topo II activity may add considerably to the toolbox of individualized medicine where decisions are based on very sparse samples.

Pan-cancer analysis reveals presence of pronounced DNA methylation drift in CpG island methylator phenotype clusters

AIM

To provide characteristics of major genomic correlates in CpG island methylator phenotype-high (CIMP-H) subgroups in relation to corresponding non-CIMP-H subgroups by use of phenotypic, DNA methylation and RNAseq data.

MATERIALS & METHODS

Twenty-three datasets generated by The Cancer Genome Atlas project encompassing over 7200 unique samples were analyzed. We identified 23 CIMP-H clusters by use of unsupervised clustering.

RESULTS & CONCLUSION

More than 90% of CIMP-H clusters were significantly associated with accelerated epigenetic mitotic clock, demethylation of enhancer sites, backbone and repetitive sequences. Pronounced epigenetic drift observed in majority of CIMP-H subgroups may be related to increased cell division rate, which leads to expansion of DNA methylation errors. This may explain pan-cancer mechanism of establishing CIMP-H in majority of tissue types.

Value of urinary topoisomerase-IIA cell-free DNA for diagnosis of bladder cancer

PURPOSE

Topoisomerase-II alpha (TopoIIA ), a DNA gyrase isoform that plays an important role in the cell cycle, is present in normal tissues and various human cancers, and can show altered expression in both. The aim of the current study was to examine the value of urinary TopoIIA cell-free DNA as a noninvasive diagnosis of bladder cancer (BC).

MATERIALS AND METHODS

Two patient cohorts were examined. Cohort 1 (73 BC patients and seven controls) provided bladder tissue samples, whereas cohort 2 (83 BC patients, 54 nonmalignant hematuric patients, and 61 normal controls) provided urine samples. Real-time quantitative polymerase chain reaction was used to measure expression of TopoIIA mRNA in tissues and TopoIIA cell-free DNA in urine samples.

RESULTS

The results showed that expression of TopoIIA mRNA in BC tissues was significantly higher than that in noncancer control tissues (p<0.001). The expression of urinary TopoIIA cell-free DNA in BC patients was also significantly higher than that in noncancer patient controls and hematuria patients (p < 0.001 and p < 0.001, respectively). High expression of urinary TopoIIA cell-free DNA was also detected in muscle invasive bladder cancer (MIBC) when compared with nonmuscle invasive bladder cancer (NMIBC) (p=0.002). Receiver operating characteristics (ROC) curve analysis was performed to examine the sensitivity/specificity of urinary TopoIIA cell-free DNA for diagnosing BC, NMIBC, and MIBC. The areas under the ROC curve for BC, NMIBC, and MIBC were 0.741, 0.701, and 0.838, respectively.

CONCLUSIONS

In summary, the results of this study provide evidence that cell-free TopoIIA DNA may be a potential biomarker for BC.

Lack of effect of metformin on mammary carcinogenesis in nondiabetic rat and mouse models

Epidemiologic studies have shown that diabetics receiving the biguanide metformin, as compared with sulfonylureas or insulin, have a lower incidence of breast cancer. Metformin increases levels of activated AMPK (AMP-activated protein kinase) and decreases circulating IGF-1; encouraging its potential use in both cancer prevention and therapeutic settings. In anticipation of clinical trials in nondiabetic women, the efficacy of metformin in nondiabetic rat and mouse mammary cancer models was evaluated. Metformin was administered by gavage or in the diet, at a human equivalent dose, in standard mammary cancer models: (i) methylnitrosourea (MNU)-induced estrogen receptor-positive (ER(+)) mammary cancers in rats, and (ii) MMTV-Neu/p53KO ER(-) (estrogen receptor-negative) mammary cancers in mice. In the MNU rat model, metformin dosing (150 or 50 mg/kg BW/d, by gavage) was ineffective in decreasing mammary cancer multiplicity, latency, or weight. Pharmacokinetic studies of metformin (150 mg/kg BW/d, by gavage) yielded plasma levels (Cmax and AUC) higher than humans taking 1.5 g/d. In rats bearing small palpable mammary cancers, short-term metformin (150 mg/kg BW/d) treatment increased levels of phospho-AMPK and phospho-p53 (Ser20), but failed to reduce Ki67 labeling or expression of proliferation-related genes. In the mouse model, dietary metformin (1,500 mg/kg diet) did not alter final cancer incidence, multiplicity, or weight. Metformin did not prevent mammary carcinogenesis in two mammary cancer models, raising questions about metformin efficacy in breast cancer in nondiabetic populations.

Synthesis and evaluation of (18)F-labeled ATP competitive inhibitors of topoisomerase II as probes for imaging topoisomerase II expression

Type II topoisomerase (Topo-II) is an ATP-dependent enzyme that is essential in the transcription, replication, and chromosome segregation processes and, as such, represents an attractive target for cancer therapy. Numerous studies indicate that the response to treatment with Topo-II inhibitors is highly dependent on both the levels and the activity of the enzyme. Consequently, a non-invasive assay to measure tumoral Topo-II levels has the potential to differentiate responders from non-responders. With the ultimate goal of developing a radiofluorinated tracer for positron emission tomography (PET) imaging, we have designed, synthesized, and evaluated a set of fluorinated compounds based on the structure of the ATP-competitive Topo-II inhibitor QAP1. Compounds 18 and 19b showed inhibition of Topo-II in in vitro assays and exhibited moderate, Topo-II level dependent cytotoxicity in SK-BR-3 and MCF-7 cell lines. Based on these results, (18)F-labeled analogs of these two compounds were synthesized and evaluated as PET probes for imaging Topo-II overexpression in mice bearing SK-BR-3 xenografts. [(18)F]-18 and [(18)F]-19b were synthesized from their corresponding protected tosylated derivatives by fluorination and subsequent deprotection. Small animal PET imaging studies indicated that both compounds do not accumulate in tumors and exhibit poor pharmacokinetics, clearing from the blood pool very rapidly and getting metabolized over. The insights gained from the current study will surely aid in the design and construction of future generations of PET agents for the non-invasive delineation of Topo-II expression.

Fibroepithelial tumors of the breast: pathologic and immunohistochemical features and molecular mechanisms

CONTEXT

The 2 main prototypes of fibroepithelial tumors of the breast include fibroadenoma and phyllodes tumor (PT). Although both tumors share some overlapping histologic features, there are significant differences in their clinical behavior and management. Phyllodes tumors have been further divided into clinically relevant subtypes, and there is more than one classification scheme for PT currently in use, suggesting a lack of consistency within different practices. Accurate differentiation between fibroadenoma and PT, as well as the grading of PT, may sometimes be challenging on preoperative core needle biopsy. Some immunohistochemical markers have been suggested to aid in the pathologic classification of these lesions.

OBJECTIVE

To discuss the salient histopathologic features of fibroepithelial tumors and review the molecular pathways proposed for the initiation, progression, and metastasis of PTs. Also, to provide an update on immunohistochemical markers that may be useful in their differential diagnosis and outline the practice and experience at our institution from a pathologic perspective.

DATA SOURCES

Sources included published articles from peer-reviewed journals in PubMed (US National Library of Medicine).

CONCLUSIONS

Fibroepithelial tumor of the breast is a heterogenous group of lesions ranging from fibroadenoma at the benign end of the spectrum to malignant PT. There are overlapping histologic features among various subtypes, and transformation and progression to a more malignant phenotype may also occur. Given the significant clinical differences within various subtypes, accurate pathologic classification is important for appropriate management. Although some immunohistochemical markers may be useful in this differential diagnosis, histomorphology still remains the gold standard.

Molecular mapping the presence of druggable targets in preinvasive and precursor breast lesions: a comprehensive review of biomarkers related to therapeutic interventions

The analysis of clinical breast samples using biomarkers is integral to current breast cancer management. Currently, a limited number of targeted therapies are standard of care in breast cancer treatment. However, these targeted therapies are only suitable for a subset of patients and resistance may occur. Strategies to prevent the occurrence of invasive lesions are required to reduce the morbidity and mortality associated with the development of cancer. In theory, application of targeted therapies to pre-invasive lesions will prevent their progression to invasive lesions with full malignant potential. The diagnostic challenge for pathologists is to make interpretative decisions on early detected pre-invasive lesions. Overall, only a small proportion of these pre-invasive lesions will progress to invasive carcinoma and morphological assessment is an imprecise and subjective means to differentiate histologically identical lesions with varying malignant potential. Therefore differential biomarker analysis in pre-invasive lesions may prevent overtreatment with surgery and provide a predictive indicator of response to therapy. There follows a review of established and emerging potential druggable targets in pre-invasive lesions and correlation with lesion morphology.

Topoisomerase II alpha gene amplification is a favorable prognostic factor in patients with HER2-positive metastatic breast cancer treated with trastuzumab

BACKGROUND

The vast majority of patients with HER2-positive metastatic breast cancer (MBC) treated with trastuzumab eventually develop resistance to this agent. There is an unmet need therefore, for identifying biological markers with possible prognostic/predictive value in such patients. The aim of this study was to investigate the prognostic role of topoisomerase II alpha gene (TOP2A) amplification and protein (TopoIIa) expression in patients treated with trastuzumab-containing regimens.

METHODS

Formalin-fixed paraffin-embedded tumor tissue samples were retrospectively collected from 225 eligible patients treated with trastuzumab. Protein expression of ER, PgR, Ki67, PTEN, HER2 and TopoIIa were centrally assessed by immunohistochemistry. HER2 and TOP2A gene amplification was evaluated by fluorescence in situ hybridization. PIK3CA mutations were identified by single nucleotide polymorphism genotyping. Survival was evaluated from the initiation of trastuzumab as 1st line treatment to the date of last follow-up or death.

RESULTS

Among the 225 samples analyzed, only 137 (61%) were found to be HER2-positive. TOP2A was amplified in 41% and deleted in 16% of such tumors. TOP2A gene amplification was more frequent in ER-negative tumors. TopoIIa protein expression was observed in the majority (65%) of the samples and was associated with ER-positive status, high Ki67 expression, presence of PTEN protein and PIK3CA mutations. Median follow-up for patients treated in the 1st line was 51 months. Survival was more prolonged with trastuzumab-containing treatment in HER2-positive patients (50 months, log-rank, p=0.007). TOP2A non-amplified or deleted tumors were associated with increased risk for death compared to TOP2A amplified tumors (HR=2.16, Wald's p=0.010 and HR=2.67, p=0.009, respectively). In multivariate analysis, a significant interaction of TOP2A with anthracycline treatment (either in the adjuvant or the 1st line setting) was observed for survival (Wald's p=0.015). Among the TOP2A amplified subgroup, anthracycline-treated patients were associated with decreased risk for death.

CONCLUSIONS

TOP2A gene amplification was shown to be a favorable prognostic marker in HER2-positive MBC patients treated with trastuzumab, such an effect however, appears to rather be related to treatment with anthracyclines (predictive marker for benefit from anthracyclines). The results of the present retrospective study warrant validation in larger cohorts of patients treated in the context of randomized trials.

Assessment of Topoisomerase II α status in breast cancer by quantitative PCR, gene expression microarrays, immunohistochemistry, and fluorescence in situ hybridization

Anthracyclines are frequently used for the treatment of breast cancer and topoisomerase II alpha (TOP2A) is considered to be the molecular target. Numerous studies have evaluated the predictive value of TOP2A using different methodological approaches and inconsistent results have been reported. Indeed, the correlation between techniques for the assessment of TOP2A status has not been well evaluated. In this study, we determined TOP2A status in 61 breast tumor samples by real-time PCR, DNA microarrays, immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH), and then evaluated these results with clinical-pathological features and breast cancer intrinsic subtypes. First, we observed a statistical significant correlation of TOP2A gene expression between real-time PCR and microarrays (Pearson coefficient, 0.816; P < 0.001), and both predicted TOP2A IHC results fairly well (area under the curve > 0.74). In contrast, poor agreement between FISH and IHC data was observed (k: 0.134). Secondly, TOP2A expression was found significantly associated with cell proliferation, and with the highly proliferative Luminal B, Her2-enriched and Basal-like intrinsic subtypes. In conclusion, TOP2A expression in breast cancer was associated with high proliferation and aggressive tumor subtypes and appears to be independent of its amplification status. All of these features should be taken into consideration when assessing the predictive value of TOP2A for anthracycline-based chemotherapy.

Novel molecular markers of malignancy in histologically normal and benign breast

To detect the molecular changes of malignancy in histologically normal breast (HNB) tissues, we recently developed a novel 117-gene-malignancy-signature. Here we report validation of our leading malignancy-risk-genes, topoisomerase-2-alpha (TOP2A), minichromosome-maintenance-protein-2 (MCM2) and “budding-uninhibited-by-benzimidazoles-1-homolog-beta” (BUB1B) at the protein level. Using our 117-gene malignancy-signature, we classified 18 fresh-frozen HNB tissues from 18 adult female breast cancer patients into HNB-tissues with low-grade (HNB-LGMA; N = 9) and high-grade molecular abnormality (HNB-HGMA; N = 9). Archival sections of additional HNB tissues from these patients, and invasive ductal carcinoma (IDC) tissues from six other patients were immunostained for these biomarkers. TOP2A/MCM2 expression was assessed as staining index (%) and BUB1B expression as H-scores (0–300). Increasing TOP2A, MCM2, and BUB1B protein expression from HNB-LGMA to HNB-HGMA tissues to IDCs validated our microarray-based molecular classification of HNB tissues by immunohistochemistry. We also demonstrated an increasing expression of TOP2A protein on an independent test set of HNB/benign/reductionmammoplasties, atypical-ductal-hyperplasia with and without synchronous breast cancer, DCIS and IDC tissues using a custom tissue microarray (TMA). In conclusion, TOP2A, MCM2, and BUB1B proteins are potential molecular biomarkers of malignancy in histologically normal and benign breast tissues. Larger-scale clinical validation studies are needed to further evaluate the clinical utility of these molecular biomarkers.

Topoisomerase II alpha expression and the Ki-67 labeling index correlate with prognostic factors in estrogen receptor-positive and human epidermal growth factor type-2-negative breast cancer

BACKGROUND

Topoisomerase II alpha (Topo IIa) is involved in DNA replication and is a molecular target for anthracycline-based chemotherapy. The Ki-67 labeling index (LI) is an evaluation of tumor cell proliferation. The objective of this study was to evaluate relationships among Topo IIa expression, the Ki-67 LI, and prognostic factors in estrogen receptor (ER)-positive, human epidermal growth factor type-2 (HER2)-negative breast cancer.

MATERIALS AND METHODS

Seventy-one patients were diagnosed with ER-positive, HER2-negative breast cancer between July 2003 and December 2004. Formalin-fixed, paraffin-embedded tumor specimens were stained for Topo IIa expression and Ki-67 LI. We investigated the correlation of the level of Topo IIa expression and the Ki-67 LI with clinical factors such as age, tumor size, progesterone receptor status, nodal status, nuclear grade, and lymphovascular invasion (LVI).

RESULTS

Statistically significant differences were observed between Topo IIa overexpression, nuclear grade (p = 0.036), and LVI (p = 0.029). Topo IIa overexpression was statistically correlated with the Ki-67 LI (p < 0.0001). A statistically significant difference was observed between the Ki-67 LI and nuclear grade (p = 0.01). Survival analysis revealed the significant prognostic value of Ki-67 LI in patients with ER-positive, HER2-negative breast cancer (p = 0.003).

CONCLUSIONS

Ki-67 LI is a strong prognostic factor in ER-positive HER2-negative breast cancer. Topo IIa overexpression was significantly correlated with the Ki-67 LI, nuclear grade, and LVI. These findings suggest use of Topo IIa expression as a proliferation marker and a prognostic factor in ER-positive, HER2-negative breast cancer.

Progesterone resistance in PCOS endometrium: a microarray analysis in clomiphene citrate-treated and artificial menstrual cycles

CONTEXT

Polycystic ovary syndrome (PCOS), the most common endocrinopathy of reproductive-aged women, is characterized by ovulatory dysfunction and hyperandrogenism.

OBJECTIVE

The aim was to compare gene expression between endometrial samples of normal fertile controls and women with PCOS.

DESIGN AND SETTING

We conducted a case control study at university teaching hospitals.

PATIENTS

Normal fertile controls and women with PCOS participated in the study.

INTERVENTIONS

Endometrial samples were obtained from normal fertile controls and from women with PCOS, either induced to ovulate with clomiphene citrate or from a modeled secretory phase using daily administration of progesterone.

MAIN OUTCOME MEASURE

Total RNA was isolated from samples and processed for array hybridization with Affymetrix HG U133 Plus 2 arrays. Data were analyzed using GeneSpring GX11 and Ingenuity Pathways Analysis. Selected gene expression differences were validated using RT-PCR and/or immunohistochemistry in separately obtained PCOS and normal endometrium.

RESULTS

ANOVA analysis revealed 5160 significantly different genes among the three conditions. Of these, 466 were differentially regulated between fertile controls and PCOS. Progesterone-regulated genes, including mitogen-inducible gene 6 (MIG6), leukemia inhibitory factor (LIF), GRB2-associated binding protein 1 (GAB1), S100P, and claudin-4 were significantly lower in PCOS endometrium; whereas cell proliferation genes, such as Anillin and cyclin B1, were up-regulated.

CONCLUSIONS

Differences in gene expression provide evidence of progesterone resistance in midsecretory PCOS endometrium, independent of clomiphene citrate and corresponding to the observed phenotypes of hyperplasia, cancer, and poor reproductive outcomes in this group of women.

Role of metalation in the topoisomerase IIα inhibition and antiproliferation activity of a series of α-heterocyclic-N4-substituted thiosemicarbazones and their Cu(II) complexes

The topoisomerase-IIα inhibition and antiproliferative activity of α-heterocyclic thiosemicarbazones and their corresponding copper(II) complexes have been investigated. The Cu(II)(thiosemicarbazonato)Cl complexes were shown to catalytically inhibit topoisomerase-IIα at concentrations (0.3-7.2 μM) over an order of magnitude lower than their corresponding thiosemicarbazone ligands alone. The copper complexes were also shown to inhibit the proliferation of breast cancer cells expressing high levels of topoisomerase-IIα (SK-BR-3) at lower concentrations than cells expressing lower levels of the enzyme (MCF-7).

Pathological tumor response to neoadjuvant chemotherapy using anthracycline and taxanes in patients with triple-negative breast cancer

Although triple-negative breast cancer (TNBC) is associated with a poor prognosis, recent reports have indicated that a higher proportion of TNBC patients shows a pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) than is the case for non-TNBC patients. The aim of this study was to identify markers that predict pCR to NAC in TNBC patients, and to clarify prognostic factors that affect the outcome of TNBC patients with residual disease (RD) after NAC. Among 44 TNBC patients who received anthracycline- and taxane-based combination NAC, we analyzed the relationship between pathological response and clinicopathological characteristics, including immunohistochemical parameters (cytokeratin 5/6, epidermal growth factor receptor, Ki-67, p53, breast cancer susceptibility protein 1 and topoisomerase IIα). We also assessed the prognostic impact on patients with RD by analyzing the correlation between disease-free survival (DFS) and clinicopathological parameters. Sixteen patients (36%) achieved a pCR and log-rank test showed that these patients had a significantly more favorable outcome than patients with RD (DFS, P=0.00184; overall survival, P=0.0080). Among the clinicopathological parameters examined, none was correlated with pathological response, with the exception of p53. Patients with immunohistochemical overexpression of p53 more frequently achieved a pCR than those without p53 overexpression (P=0.0484). In the patients with RD, the Cox proportional hazards model showed that the presence of lymphovascular invasion was significantly associated with shorter DFS (hazard ratio, 13.333; 95% CI 1.587-111.111; P=0.0171). p53 overexpression may be a key predictor of a favorable response to NAC. Since patients with RD, particularly those positive for lymphovascular invasion, had an extremely poor outcome, novel therapeutic approaches for these patients are warranted.

TOPOIIalpha and HER-2/neu overexpression/amplification in Barrett's oesophagus, dysplasia and adenocarcinoma

Rossi E, Villanacci V, Bassotti G, Donato F, Festa A, Cengia G, Grisanti S & Cestari R (2010) Histopathology57, 81–89 TOPOIIα and HER-2/neu overexpression/amplification in Barrett’s oesophagus, dysplasia and adenocarcinoma

Histopathological prognostic factors in early breast carcinoma: an evaluation of cell proliferation in carcinoma cells

Early breast carcinoma is defined as pathological stage 1 (pT1N0M0) tumour and its incidence has recently increased possibly due to the advent of mammography based mass screening. Overall survival of these patients is in general excellent, but more than 20% of them will eventually develop distant metastasis and die. Therefore, an establishment of prognostic factors could contribute greatly to determining the algorithm for treating these patients after surgery. Histopathological prognostic factors still play pivotal roles in the management of these patients. Among these, Nottingham histological grade is considered the gold standard for determining the clinical outcome of early breast cancer patients if done in optimally processed tissue specimens by well-trained pathologists. Among these histological factors of Nottingham histological grade, mitotic index has been demonstrated to provide the most significant information as to prognosis of these patients. Attempts have been made to assess the status of tumour cell proliferation in practical, reproducible and accurate manners in the past. Among these attempts, immunohistochemical analysis of cell cycle associated nuclear antigens, especially Ki67/MIB1 labelling index in archival materials, has been reported to provide clinically inert and significant information. However, its methodologies, including processing of the specimens, and modes of interpretation should be standardised before this Ki67/MIB1 labelling index can become incorporated into routine clinical practice in the management of early breast carcinoma patients.

Clinical implications and prognostic values of topoisomerase-II alpha expression in primary non-muscle-invasive bladder cancer

OBJECTIVES

To investigate the association between expression levels of topoisomerase-II alpha (TOP-2alpha) and prognosis in primary non-muscle-invasive bladder cancer (NMIBC). TOP-2alpha, a marker of cell proliferation, has been assessed as a prognostic indicator in several types of cancer. However, currently available data on the role of TOP-2alpha in prognosis are inconsistent.

METHODS

Top-2alpha messenger ribonucleic acid (mRNA) levels were examined in 103 tumor specimens from patients with primary NMIBC by real-time polymerase chain reaction. Immunohistochemical staining was performed on 39 matched tumor samples. The median follow-up period for all patients was 51.8 months (range, 3.2-137).

RESULTS

The mRNA expression levels of TOP-2alpha were significantly elevated in subjects with high-grade (P<.001) and high-stage (P=.041) tumors as compared with subjects with low-grade and low-stage tumors. Kaplan-Meier estimates revealed significant variation in tumor recurrence and progression depending on the level of TOP-2alpha expression (log-rank test, P<.05). Multivariate Cox regression analysis revealed that the level of TOP-2alpha expression is a strong predictor of recurrence (hazard ratio, 2.507; 95% confidence interval, 1.228-5.116; P=.012) and progression (hazard ratio, 4.192; 95% confidence interval, 1.002-17.536; P=.049) for NMIBC. The results of immunohistochemical staining generally correlated with mRNA expression levels.

CONCLUSIONS

Enhanced expression of TOP-2alpha is positively associated with a high rate of recurrence and progression in NMIBC. Thus, TOP-2alpha represents a promising marker of prognosis for NMIBC.

Topoisomerase IIalpha mRNA and protein expression in ovarian carcinoma: correlation with clinicopathological factors and prognosis

Topoisomerase IIalpha (Top IIalpha) is a nuclear enzyme that plays a central role in DNA metabolism, and is a molecular target for a variety of chemotherapeutic agents. Top IIalpha has recently gained attention as a biomarker for therapy response and patient survival. In this study, we attempted to assess the feasibility of measuring Top IIalpha gene expression in RNA, isolated from archival formalin-fixed paraffin-embedded tissue specimens, which are used routinely in pathology laboratories. We have employed a new technique on the basis of magnetic particles' separation and purification of nucleic acids, and evaluated both protein and mRNA expressions from the same routinely processed tissue blocks. We investigated the expression of Top IIalpha mRNA and protein by real-time reverse transcription polymerase chain reaction and immunohistochemistry, in a cohort of 133 primary ovarian carcinomas, and evaluated the association between Top IIalpha expression and clincopathological variables as well as patient outcome. Elevated Top IIalpha mRNA expression was observed in high-grade tumors (P=0.003) and advanced stage disease (P=0.011). In univariate Kaplan-Meier analysis, patients with higher expression of Top IIalpha nuclear protein had a significantly decreased overall survival (P=0.045). Interestingly, we detected cytoplasmic protein expression of Top IIalpha in a subset of samples. Cytoplasmic expression of Top IIalpha was associated with the expression of chromosomal region maintenance/exportin 1 (CRM1)-a nuclear export protein (P=0.008). Our study suggests that Top IIalpha overexpression is involved in the progression of ovarian cancer in a subset of the patients. Our results encourage the further evaluation of the prognostic and predictive values of Top IIalpha expression in ovarian carcinoma, which might help to assess the patients' risk profile, and the planning of an individualized therapy.

The significance of Epstein Barr virus (EBV) & DNA topoisomerase II alpha (DNA-Topo II alpha) immunoreactivity in normal oral mucosa, oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC)

Background

Head and neck cancer including oral cancer is considered to develop by accumulated genetic alterations and the major pathway is cancerization from lesions such as intraepithelial dysplasia in oral leukoplakia and erythroplakia. The relationship of proliferation markers with the grading of dysplasia is uncertain. The involvement of EBV in oral carcinogenesis is not fully understood.

Aim

The present study was designed to investigate the role of EBV and DNA Topoisomerase II∝ (DNA-Topo II∝) during oral carcinogenesis and to examine the prognostic significance of these protein expressions in OSCCs.

Methods

Using specific antibodies for EBV and DNA-Topo II∝, we examined protein expressions in archival lesion tissues from 16 patients with oral epithelial dysplasia, 22 oral squamous cell carcinoma and 20 normal oral mucosa by immunohistochemistry. Clinical information was obtained through the computerized retrospective database from the tumor registry.

Results

DNA-Topo II∝ was expressed in all examined specimens. Analysis of Variance ANOVA revealed highly significant difference (P < 0.01) in young aged labial tissues and significant (P ≤ 0.05) in gingival and not significant (P > 0.05) in inferior surface of tongue and in hard palatal tissues. Significant differences were observed between OEDs and NSE (P < 0.001) and SCCs and controls (P < 0.001), also, significant differences could be observed between SCCs and OEDs. DNA-Topo II∝ expression was significantly higher in tumors of low differentiation versus tumors of moderate and high differentiation (P < 0.001), DNA-Topo II∝ expression was correlated with age, tumor size, tumor stage, node metastasis and tumor differentiation, but not with gender and tumor site. None of normal squamous epithelium (NSE) expressed EBV. Heterogenous reactivity for EBV was observed through the series of dysplasia and squamous cell carcinoma. Its expression increased progressively with lymph node metastasis and low tumor differentiation, but no significant association could be observed with other clinicopathological parameters. EBV protein expression was increased with elevated Topo II-∝ LI in OEDs and OSCCs. A tendency to positive correlation between EBV and Topo II∝ expression was observed in OEDs but not in OSCCs.

Conclusion

EBV and DNA Topo II-αLI expression are possible indicators in oral carcinogenesis and may be valuable diagnostic and prognostic indices in oral carcinoma.

Human topoisomerase II-alpha is highly expressed in sinonasal-inverted papilloma, but not in inflammatory polyp

Sinonasal-inverted papilloma is a benign tumour with a high rate of recurrence, but possible malignant transformation. Therefore, inves tigation of predisposition to malignant transformation of sinonasal-inverted papilloma gives clinicians the opportunity for adequate trea ment. Topoisomerase II-α (topoII-α) and Ki67 are markers of cell proliferation in both normal and neoplastic tissues and its level o expression could be used as a predictive parameter. Our goal was to investigate by immunochemistry the expression level of topoII-in inverted papilloma, inflammatory nasal polyp and normal sinonasal epithelium and to compare it with expression level of Ki67. TopoI α nuclear immunostaining showed a differential positivity in the investigated cases. The topoII-α index was 30.6 ± 12.8 in inverte papilloma, 10.7 ± 6.6 in the adjacent epithelium of inverted papilloma, but only 2.3 ± 2.0 in the normal sinonasal epithelium. The di ferences in topoII-α expression between inverted papilloma and normal sinonasal epithelia were statistically significant. In inflammator nasal polyp group, topoII-α index was 2.4 ± 2.1, and the difference in the topoII-α index between inverted papilloma and inflammator polyp group was also statistically significant. Nuclear immunostaining for Ki67 followed a similar variation. The Ki67 index was 50.0 ± 20. in inverted papilloma, 9.0 ± 6.6 in the adjacent epithelium of inverted papilloma and 2.4 ± 0.9 in normal sinonasal epithelium. The di ferences in Ki67 expression between inverted papilloma and either adjacent or normal sinonasal epithelia were statistically significan Significant correlation coefficients were found between topoII-α and epithelial thickness (r = 0.70, P > 0.0001), and between Ki67 inde and epithelial thickness (r = 0.71, P> 0.0001). In the inflammatory nasal polyp group Ki67 index was 5.9 ± 3.4. The difference in th Ki67 index between inverted papilloma and inflammatory nasal polyp groups was statistically significant. Significant correlation coeff cient was found between topoII-α index and Ki67 index in inverted papilloma (r = 0.42, P > 0.05). These results suggest that the inverte papilloma contains a significantly higher cell population with proliferative activity by comparison with normal sinonasal and inflamma tory polyp epithelia, showing a significant correlation between topoII-α and Ki67 expression, and indicating that topoII-α could be a independent prognostic factor for a putative malignant transformation.

Topoisomerase IIalpha expression as an independent prognostic factor in Hodgkin's lymphoma

PURPOSE

To correlate the immunohistochemical expression of topoisomerase IIalpha (topoIIalpha) in Hodgkin's lymphoma (HL) with clinicopathological parameters, the expression of Ki-67 and the outcome of patients, who had been homogenously treated with ABVD or equivalent regimens.

EXPERIMENTAL DESIGN

Immunohistochemistry using the monoclonal antibody Ki-S1 (topoIIalpha) was performed in 238 HL patients. MiB1 (Ki-67) expression was evaluated in 211/238.

RESULTS

The mean +/- SD percentage of topoIIalpha- and Ki-67-positive Hodgkin-Reed-Sternberg (HRS) cells was 63 +/- 19% (5%-98%) and 73 +/- 19% (8%-99%), respectively. The median percentage of topoIIalpha-positive HRS cells was 64% (interquartile range, 51-78%). There was no correlation between topoIIalpha expression and patient characteristics. TopoIIalpha and Ki-67 expression were correlated (Spearman's Rho 0.255, P < 0.001). TopoIlalpha expression within the highest quartile of this patient population was predictive of failure free survival (FFS) (10-year rates 82 +/- 3% vs 68 +/- 7%, P = 0.02 for patients falling into the quartiles 1-3 and 4 respectively). In multivariate analysis topoIIalpha expression was independently predictive of FFS.

CONCLUSION

TopoIIalpha was expressed in all cases of HL showing a correlation with Ki-67 expression. Under current standard therapy including drugs inhibiting its activity, topoIIalpha was an independent adverse predictor of FFS with no statistically significant correlation with other established prognostic factors.

p-53 gene mutations as a predictive marker in a population of advanced breast cancer patients randomly treated with doxorubicin or docetaxel in the context of a phase III clinical trial

BACKGROUND

Preclinical data indicate that p-53 gene mutations predict resistance to doxorubicin (A) but not to docetaxel (Taxotere) (T). In the TAX 303 trial, A and T have been compared with advanced breast cancer patients.

PATIENTS AND METHODS

Primary tumor samples from patients participating in the TAX 303 trial were collected. p-53 gene mutations were evaluated by denaturing high-performance liquid chromatography (DHPLC) and confirmed by sequencing. Topoisomerase II alpha (topo II alpha) protein levels were evaluated by immunohistochemistry. Clinical and biological data were correlated.

RESULTS

Tumor samples for DHPLC analysis were available for 108 of 326 patients from the clinical trial. p-53 gene mutations were observed in 20% of patients. In patients with a mutated p-53 gene, a trend for a lower percentage of responders was observed in the A arm (17%) compared with the T arm (50%). In the wild-type p-53 cohort, response rates to A and T were 27% and 36%, respectively. Of the 16 patients carrying wild-type p-53- and topo II protein-positive tumors, seven (44%) responded to anthracyclines, while response rate to the same drug was 13% in the remaining cohorts [odds ratio 5.06 (95% confidence interval 1.19-21.41), P = 0.03]. The combination of the two markers had no predictive value in patients treated with docetaxel.

CONCLUSIONS

(i) p-53 gene analysis indicates that gene mutations may compromise the efficacy of A while they do not interfere with the antitumor activity of T; and (ii) the evaluation of multiple molecular markers including p-53 and proliferation markers as topo II protein levels looks more promising in predicting response to anthracyclines.

Measuring proliferation in breast cancer: practicalities and applications

Various methods are available for the measurement of proliferation rates in tumours, including mitotic counts, estimation of the fraction of cells in S-phase of the cell cycle and immunohistochemistry of proliferation-associated antigens. The evidence, advantages and disadvantages for each of these methods along with other novel approaches is reviewed in relation to breast cancer. The potential clinical applications of proliferative indices are discussed, including their use as prognostic indicators and predictors of response to systemic therapy.

Expression of tissue inhibitor of matrix metalloproteinases (TIMP)-3 protein in invasive breast carcinoma: relation to tumor phenotype and clinical outcome

Introduction

Our aim was to study the expression pattern of tissue inhibitor of metalloproteinases (TIMP)-3 protein in invasive breast carcinoma, and its clinicopathological and prognostic value as well as its relation to markers indicative of the tumor phenotype.

Methods

Immunohistochemistry was performed on paraffin-embedded tissue specimens from 173 invasive breast carcinomas to detect the proteins TIMP-3, estrogen receptor (ER), progesterone receptor, p53, c-erbB-2, topoisomerase IIα and Bcl-2.

Results

TIMP-3 protein was immunodetected in the cytoplasm of the malignant cells and the peritumoral stroma, as well as in in situ carcinoma and normal epithelium. Reduced expression of TIMP-3 protein within cancer cells was correlated with carcinomas of high nuclear and histological grade (p = 0.032 and p = 0.015, respectively), and low ER expression (p = 0.053). Moreover, TIMP-3 immunopositivity was inversely correlated with the expression of p53 and topoIIα proteins (p = 0.002 and p = 0.008, respectively), whereas it was positively associated with Bcl-2 expression (p = 0.020). Reduced expression of TIMP-3 protein within cancer cells was found to have an unfavorable impact on disease-free survival (p = 0.052) in the entirety of the patient population, as well as in both subgroups of lymph-node-positive and mutant-p53-negative patients (p = 0.007 and p = 0.037, respectively). Stromal localization of TIMP-3 protein was found to have no clinicopathological or prognostic value.

Conclusion

This is the first immunohistochemical study to show that TIMP-3 protein within cancer cells is associated with tumor phenotype. Reduced expression of TIMP-3 protein within cancer cells was found to correlate with an aggressive tumor phenotype, negatively affecting the disease-free survival of both subgroups of lymph node-positive and mutant-p53-negative patients.

Immunohistochemical study on topoisomerase IIα, Ki-67 and cytokeratin-19 in oral lichen planus lesions

Oral lichen planus (OLP) is a chronic muco-cutaneous inflammatory disease defined as a precancerous condition. We determined the expression patterns of proliferation markers topoisomerase IIalpha (topo IIalpha) and Ki-67 and an intermediated filament protein cytokeratin-19 (CK-19) in atrophic OLP. These markers were selected because our recent microarray analysis indicated they might aid in identification of potentially malignant lesions. The expression patterns were correlated with the DNA content of these lesions shown to be useful in detection lesions at risk for malignant transformation of OLP. A series of 81 formalin-fixed, paraffin-embedded biopsies from 70 patients suffering from atrophic OLP were immunostained with monoclonal antibodies against topo IIalpha, Ki-67 and CK-19 using standard methods. Of the 70 patients, there were eight patients who had dysplastic changes in OLP lesions. During the follow-up, altogether five patients got cancer in the OLP area even though no dysplastic changes were present in the preceding lesion. On light microscopy, 500 cells were examined in the basal and parabasal epithelial layers of biopsy samples at 400x magnification. All biopsy samples were topo IIalpha positive and approximately 70% of the counted cells were positive. Strong staining of topo IIalpha was significantly correlated with dysplasia (P = 0.019), basal cell hyperplasia (P = 0.005) and ulceration (P = 0.008) in the samples. Ki-67 was expressed in all samples but only 36% of the cells were positive. CK-19 positivity was found in 29% of the specimens. Histological parameters were not related to either Ki-67 or CK-19. The comparison of the staining patterns with the DNA content of lesions showed that strongly stained cells with topo IIalpha were significantly more frequent in the samples with 2.5cER higher than 15% than in those below 15% (P = 0.013; Mann-Whitney). The percentage of the measured cells is 2.5cER exceeding the 2.5c value on the DNA scale. We earlier showed that this cut-off value of 2.5cER discriminated DNA aneuploidy. To conclude, topo IIalpha is a proliferation and also an apoptotic marker in atrophic OLP lesions and it might have a predictive value in oral lichen planus lesions prone to develop malignancy.

Over-expression of topoisomerase IIalpha is related to the grade of cervical intraepithelial neoplasia (CIN) and high-risk human papillomavirus (HPV), but does not predict prognosis in cervical cancer or HPV clearance after cone treatment

OBJECTIVE

One of the pathways leading to cervical cancer is a loss of normal cell cycle control. Topoisomerase IIalpha and IIbeta are important nuclear proteins controlling the G2/M checkpoint, and shown to be over-expressed in many human cancers. Their links to oncogenic human papillomavirus (HPV) types and their prognostic value in cervical cancer are practically unexplored.

MATERIAL AND METHODS

As part of our HPV-PathogenISS study, a series of 150 squamous cell carcinomas (SCC) and 152 CIN lesions were examined using immunohistochemical (IHC) staining for topoisomerase IIalpha (topo IIalpha), and tested for HPV using PCR with three primer sets (MY09/11, GP5/GP6, SPF). Follow-up data were available from all SCC patients, and 67 CIN lesions had been monitored with serial PCR for HPV clearance/persistence after cone treatment.

RESULTS

Topo IIalpha expression increased with increasing grade of CIN (p = 0.0001), with the most dramatic up-regulation upon progression from CIN2 to CIN3 and peaking in SCC (OR 16.23; 95%CI 7.89-33.38). Topo IIalpha up-regulation was also significantly associated with HR-HPV detection in univariate analysis (OR = 3.07; 95%CI 1.70-5.52), but was confounded by the histological grade (Mantel-Haenszel common OR = 1.622; 95%CI 0.782-3.365), and by entering both p16(INK4a) (9) and Survivin (33) in the multivariate regression model. Topo IIalpha did not predict clearance/persistence of HR-HPV after treatment of CIN, and it was not a prognostic factor in cervical cancer in either univariate or multivariate analysis.

CONCLUSIONS

Over-expression of topo IIalpha is significantly associated with progression from CIN2 to CIN3, being a late marker of cell proliferation. Its close association with HR-HPV is plausibly explained by the fact that E7 oncoproteins of these HR-HPV (but not LR-HPV) block the normal pRb-mediated inhibition of topo IIalpha by degrading the wild-type Rb.

Topoisomerase IIalpha gene amplification in gastric carcinomas: correlation with the HER2 gene. An immunohistochemical, immunoblotting, and multicolor fluorescence in situ hybridization study

Topoisomerase IIalpha (topoIIalpha) is an enzyme required for DNA replication and a molecular target for drugs called anthracyclines. The topoIIalpha gene (TOP2A) is located close to the HER-2/neu oncogene (HER2). We assessed gastric cancers to (1) clarify the relationship between gene amplification and protein overexpression of topoIIalpha and HER2; (2) evaluate the correlation between gene amplification and protein overexpression of topoIIalpha; and (3) examine the relationship between the results of immunohistochemistry and Western blot analysis for topoIIalpha. In a combined analysis of immunohistochemistry and fluorescence in situ hybridization on 552 formalin-fixed and paraffin-embedded gastric cancer tissues, 38 cases were found to have HER2 amplification. Further examination by fluorescence in situ hybridization revealed amplification of TOP2A in 13 of the 38 cases. No aberrations in the TOP2A gene were observed in cases without HER2 overexpression, except for one containing a gene deletion. The TopoIIalpha protein-labeling index was not correlated with TOP2A amplification. Fluorescence in situ hybridization was performed on nuclear imprint specimens obtained from 9 cases using simultaneous probes for TOP2A, HER2, and centromere 17. Of these 9 cases, 3 displayed coamplification of TOP2A and HER2, and only 1 of the 3 cases revealed a high expression of topoIIalpha in Western blot. Although patients having gastric adenocarcinoma with TOP2A amplification could be considered suitable for clinical trials, information involving anthracycline therapy is not firmly understood in regards to the status of TOP2A amplification or protein overexpression. Therefore, results of the current study will provide further insight for the clinical application of anthracycline in gastric cancers.

Topoisomerase II alpha expression correlates with diminished disease-free survival in invasive breast cancer

PURPOSE

Topoisomerase II alpha (Topo II alpha) plays a role in DNA replication and is the molecular target for anthracyline-based chemotherapy. The purpose of this study was to evaluate the relationship between Topo II alpha expression and survival in patients with invasive breast cancer.

METHODS AND MATERIALS

Formalin-fixed, paraffin-embedded tumor specimens from 24 women with invasive breast cancer were stained for Topo II alpha expression. All women underwent mastectomy. Radiotherapy was given at the University of Utah Department of Radiation Oncology. Of the patients, 23 (96%) received chemotherapy. The level of Topo II alpha expression within tumor cells was compared with clinical factors and overall survival.

RESULTS

The median percentage of tumor cells expressing Topo II alpha was 70%. Increased Topo II alpha tumor expression significantly correlated with diminished disease-free survival. Five-year disease-free survival was 100% for patients with <70% of breast cancer cells expressing Topo II alpha compared with 42% for patients with > or =70% Topo II alpha expression (p = 0.008). The level of Topo II alpha expression within tumor cells correlated with T stage (p = 0.008) but not with other pathologic factors.

CONCLUSIONS

Increased Topo II alpha expression significantly correlated with diminished disease-free survival in patients with invasive breast cancer. These findings may indicate a role for Topo II alpha expression as a prognostic factor in breast cancer.

Overexpression of cyclooxygenase-2 is associated with a favorable prognostic phenotype in breast carcinoma

OBJECTIVES

Cyclooxygenase (COX) is the rate-limiting enzyme that catalyzes the conversion of arachidonic acid to prostaglandins. The purpose of the present study was to investigate the involvement of COX-2 protein in breast cancer biological behavior through its correlation with the well-known clinicopathological parameters and the expression of p53, c-erbB-2, topoisomerase IIalpha (topoIIalpha) and peroxisome proliferator-activated receptor (PPARgamma) proteins, as well as its effect on patients' survival.

METHODS

We performed immunohistochemistry to detect COX-2, estrogen receptor (ER), progesterone receptor (PR), p53, c-erbB-2, topoIIalpha and PPARgamma proteins in 175 cases of invasive breast carcinomas. The results were elaborated by statistic analysis.

RESULTS

Cytoplasmic expression of COX-2 was detected in 66.9% of breast carcinoma samples and was inversely correlated with both nuclear and histological grade (p < 0.0001 and p = 0.039, respectively), whereas its association with PR was found to be positive (p = 0.016). COX-2 expression was inversely correlated with topoIIalpha and p53 (p = 0.033 and p = 0.002, respectively), whereas its association with PPARgamma was parallel (p < 0.0001). In addition, c-erbB-2 of tumor cells was inversely correlated with COX-2 in stromal cells of the tumor (p = 0.011). Neither univariate nor multivariate analysis demonstrated any association between COX-2 expression and patient overall or disease-free survival.

CONCLUSIONS

The current data suggest that increased expression of COX-2 may be related to breast carcinomas with less aggressive phenotype. This suggestion is further supported by the positive correlation between COX-2 and PPARgamma, since the latter is considered to be indicative of a less malignant phenotype of tumor cells.

3,3'-diindolylmethane is a novel topoisomerase IIalpha catalytic inhibitor that induces S-phase retardation and mitotic delay in human hepatoma HepG2 cells

Epidemiological evidence suggests that high consumption of Brassica genus vegetables, such as broccoli, cabbage, and Brussels sprouts, is very effective in reducing the risks of several types of cancers. 3,3'-Diindolylmethane (DIM), one of the most abundant and biologically active dietary compounds derived from Brassica genus vegetables, displays remarkable antitumor activity against several experimental tumors. In the present study, we demonstrate for the first time that DIM is a novel catalytic topoisomerase IIalpha inhibitor. In supercoiled DNA relaxation assay and kinetoplast DNA decatenation assay, DIM strongly inhibited DNA topoisomerase IIalpha and also partially inhibited DNA topoisomerases I and IIbeta. DIM did not stabilize DNA cleavage complex and did not prevent etoposide-induced DNA cleavage complex formation. Further experiments showed that DIM inhibited topoisomerase IIalpha-catalyzed ATP hydrolysis, which is a necessary step for the enzyme turnover. In cultured human hepatoma HepG2 cells, DIM blocked DNA synthesis and mitosis in a concentration-dependent manner, which was consistent with the outcome of topoisomerase inhibition in these cell-cycle phases. Our results identified a new mode of action for this intriguing dietary component that might be exploited for therapeutic development.

Immunohistochemical Detection of Human Telomerase Reverse Transcriptase (hTERT), Topoisomerase II?? Expression, and Apoptosis in Endometrial Adenocarcinoma and Atypical Hyperplasia

This study evaluated the immunohistochemical expression of human telomerase reverse transcriptase (hTERT) in endometrial carcinoma and atypical endometrial hyperplasia, and related it to the expression of topoisomerase (TP)IIalpha (a proliferation associated enzyme); apoptosis as determined by the frequency of apoptotic bodies (ABI); mitotic counts; and other clinicopathologic variables. Immunoreactivity for hTERT and TPIIalpha as well as ABI were assessed in 57 endometrial samples (12 atypical hyperplasias, 33 endometrioid carcinomas, 12 serous/clear cell carcinomas). hTERT immunoreactivity, TPIIalpha labeling indices (LI), ABI, and ratios of the indices (ABI/TPIIalpha LI) increased from atypical hyperplasias to endometrioid carcinomas to serous/clear cell carcinomas (p < 0.0001 for each variable). hTERT expression increased with ABI (p < 0.0001), TPIIalpha LI (p = 0.0019), ABI/TPIIalpha ratios (p < 0.0001), and grade (p = 0.0005), but not with FIGO stage (p = 0.2775). TPIIalpha LI, ABI, and ratios were related to high grade (p = 0.0001 for each variable), but not with FIGO stage (p = 0.7362, p = 0.7554, and p = 0.7405, respectively). TPIIalpha LI and ABI were significantly correlated in atypical hyperplasias (p = 0.0004), endometrioid carcinomas (p < 0.0001), and serous/clear cell carcinomas (p = 0.024). Immunostaining levels for hTERT were similar in atypical hyperplasias and grade 1 endometrioid carcinomas (p = 0.1956). These results suggest that hTERT expression is closely related to proliferation, apoptosis, and high grade in endometrial carcinomas, reflecting cell cycle deregulation in endometrial carcinogenesis.