HER-2/neu and topoisomerase IIalpha in breast cancer

Real-world data of subcutaneous trastuzumab and intravenous pertuzumab as neoadjuvant therapy for localized HER2+ breast cancer in Panama

The aim of this study is to determine the effectiveness of subcutaneous trastuzumab in combination with intravenous pertuzumab and chemotherapy for patients with HER2-overexpressing localized breast cancer treated in our center. Methods: This was a descriptive, retrospective, real-world study. Results: Of 156 patients, pathological complete response (pCR) was achieved in 64.1%. A multivariate analysis showed a relationship with a negative hormone receptor (HR) expression and a HER2 score of 3+ by immunohistochemistry. Relapse-free survival (RFS) was higher in patients with pCR. Conclusion: Neoadjuvant therapy with dual blockade using intravenous pertuzumab and subcutaneous trastuzumab for HER2+ localized breast cancer in routine clinical practice resulted in a 64.1% pCR rate. Additionally, this outcome was related to a negative HR expression and HER2 overexpression, and correlated with higher relapse-free survival.

LncRNA XIST promotes chemoresistance of breast cancer cells to doxorubicin by sponging miR-200c-3p to upregulate ANLN

The resistance of breast cancer cells to drugs is a major obstacle to effective cancer chemotherapy. Here, we study the function mechanisms of long non-coding RNA XIST in chemoresistance of breast cancer to doxorubicin. We examined the 50% inhibitive concentration of doxorubicin to MDA-MB-231 and MDA-MB-231/ADM cells, showing that the doxorubicin resistance of MDA-MB-231/ADM cells was much higher than MDA-MB-231 cells. The gene or protein expression of XIST and ANLN were also higher in MDA-MB-231/ADM cells than that in MDA-MB-231 cells. Moreover, XIST overexpression promoted cell proliferation and inhibited apoptosis of doxorubicin-treated MDA-MB-231 cells by promoting ANLN expression. XIST silencing inhibited cell proliferation and promoted apoptosis of doxorubicin-treated MDA-MB-231/ADM cells by inhibiting ANLN expression. Luciferase reporter assay showed that XIST functioned as a competing endogenous RNA to repress miR-200c-3p, which controlled its downstream target ANLN. In conclusion, these data reveal that XIST promotes chemoresistance of breast cancer cells to doxorubicin by sponging miR-200c-3p to upregulate ANLN. This work explores the relationship between lncRNA XIST and doxorubicin resistance in breast cancer cells and highlights a novel therapeutic target for the treatment of breast cancer.

Recurrent Glioblastomas Exhibit Higher Expression of Biomarkers with Stem-like Properties

Background

Despite advances in the treatment of glioblastoma (GBM), the prognosis of patients continues to remain dismal. This unfavorable prognosis is mainly attributed to the tumor's propensity for progression and recurrence, which in turn is due to the highly aggressive nature of the persisting GBM cells that actively egress from the main tumor mass into the surrounding normal brain tissue. Such a recurrent tumor described to have a more malignant potential is highly invasive and resistant to current therapies, probably due to increased stemness and preferential selection of therapy-resistant clones of tumor cells. However, there is a paucity of literature on the expression of biomarkers in the recurrent GBM tumors that could have a role in conferring this aggressiveness.

Aim

To identify the differences in the expression pattern of selected biomarkers in paired tissue samples of GBM.

Material and Methods

A retrospective study on 30 paired samples of GBM (newly diagnosed/primary and recurrent) archived in the Department of Neuropathology, NIMHANS (2006-2009), was carried out. After obtaining clinical and demographic details, tumors were characterized histomorphologically and immunohistochemically on formalin-fixed paraffin-embedded tissues with reference to expression of biomarkers such as p53, epidermal growth factor receptor (EGFR), insulin-like growth factor binding protein 3 (IGFBP-3), sex determining region Y-box 2 (SOX2), and topoisomerase 2 A (Top2A). The results were statistically analyzed.

Results

It was observed that while p53 and IGFBP-3 expression remained unaltered in paired samples, a significant increase in the expression of EGFR (P < 0.01) was noted in the recurrent tumors. Among the other biomarkers, SOX2 expression was higher in the recurrent tumors when compared to the primary tumors (P < 0.01). Conversely, the expression of Top2A was reduced in recurrent tumors (P = 0.05). Mild elevation in the expression of IGFBP-3 was observed in recurrent tumors but was not statistically significant.

Conclusion

A significant increase in the expression of SOX2 in recurrent tumors probably indicates the presence of undifferentiated cells with stem-like properties in these tumors. EGFR is known to mediate SOX2 expression thereby resulting in stemness of the glioma cancer cells, which could further explain its overexpression in recurrent GBMs. Furthermore, a decreased expression of TOP2A observed in the recurrent tumors could probably be due to reduction in chemosensitivity to temozolomide, which has been shown in earlier studies. We also noted that p53 expression remained unaltered in the recurrent tumors when compared to the primary, suggesting the absence of preferential clonal expansion of p53 mutant cells following exposure to radiochemotherapy. Our study reiterates the fact that GBM recurrences are associated with molecular alterations that probably contribute to radiochemoresistance, increased invasiveness, therapeutic efficacy, and stemness.

Association between Immunohistochemical Expression of Topoisomerase IIα, Her2 and Hormone Receptors and Response to Primary Chemotherapy in Breast Cancer

The aim of this study was to evaluate the association between immunohistochemical expression of topoisomerase IIα, HER2 and hormone receptors and response to primary anthracycline-based chemotherapy in locally advanced breast cancer. We analyzed 109 medical charts of patients treated with primary anthracycline-based chemotherapy in the Women's Integral Health Care Center from 1996 to 2004. The clinical and pathological response to primary chemotherapy was associated with topoisomerase IIα and HER2 expression and hormone receptor negativity. Statistical analysis was performed using chi-squared, Fisher's exact test and Mann-Whitney test. No statistical association between clinical response and expression of topoisomerase IIa, HER2 and hormone receptor negativity was found. However, there was an association between complete pathological response and hormone receptor negativity (P = 0.0289). The present study suggested that these markers should not be considered predictors of response to primary anthracycline-based chemotherapy, and prospective studies must be designed for this purpose.

A human Fab exclusively binding to the extracellular domain of LMP2A

In the areas of North Africa, Southeast Asia as well as South China, Nasopharyngeal carcinoma (NPC) is among the most widespread cancers. Plenty of research findings confirmed that Epstein-Barr virus (EBV) played a crucial role in NPC. EBV-encoded Latent membrane protein 2A (LMP2A) which continuously expressed in cell membrane protein induced an epithelial-mesenchymal transition and increased the number of side population stem-like cancer cells in NPC. This reveals that LMP2A could contribute to the development and recurrence in NPC. Above evidences suggest that LMP2A could be the potential target molecule in the treatment of NPC. In the current study, a novel human antibody Fab (Fab29) against the extracellular domain of LMP2A was produced with success. Through immunofluorescence experiment it was proved that human antibody Fab29 exclusively combined the surface of SUNE cells (LMP2A-positive). Then flow cytometry result exhibited that the fluorescent intensities of SUNE cells and CNE cells were distinct (96.89% and 0.02% respectively). After that, it was shown by affinity test that the Fab29 fragment had high affinity (KD (M) 1.79E-09) with LMP2A. It was also revealed by immunohistochemical analysis that the Fab29 fragment could combine with LMP2A-positive human NPC tissues in comparison with the control group. Finally, the MTT result indicated that the Fab29 fragment could inhibit the proliferation of LMP2A-positive NPC cells. The inhibiting rate to SUNE cell proliferation reached a peak by Fab29 (19.67%) compared with unrelated Fab and CNE with Fab29 at a concentration of 500 μg/L in first 24 h and in the next 24 h the inhibition rate grew to 22.54%. In brief, it was shown that Fab29, a characteristic human antibody, could recognize LMP2A protein and inhibit the proliferation of LMP2A-expressing NPC cells in vitro.

Gene amplification: mechanisms and involvement in cancer

Gene amplification was recognized as a physiological process during the development of Drosophila melanogaster. Intriguingly, mammalian cells use this mechanism to overexpress particular genes for survival under stress, such as during exposure to cytotoxic drugs. One well-known example is the amplification of the dihydrofolate reductase gene observed in methotrexate-resistant cells. Four models have been proposed for the generation of amplifications: extrareplication and recombination, the breakage-fusion-bridge cycle, double rolling-circle replication, and replication fork stalling and template switching. Gene amplification is a typical genetic alteration in cancer, and historically many oncogenes have been identified in the amplified regions. In this regard, novel cancer-associated genes may remain to be identified in the amplified regions. Recent comprehensive approaches have further revealed that co-amplified genes also contribute to tumorigenesis in concert with known oncogenes in the same amplicons. Considering that cancer develops through the alteration of multiple genes, gene amplification is an effective acceleration machinery to promote tumorigenesis. Identification of cancer-associated genes could provide novel and effective therapeutic targets.

TOP2A amplification and overexpression in hepatocellular carcinoma tissues

Hepatocellular carcinoma (HCC) is the leading cause of cancer death in men worldwide owing to limited insights into pathogenesis and unsatisfactory efficacy of current therapies. HER2 and TOP2A genes are coamplified in breast and some other cancers. In this study, we investigated gene aberrations of HER2 and TOP2A and protein expressions of HER2, TOP2A, Ki-67, and p53 in tumor and matched nontumor tissues, as well as their associations with clinicopathological features. Gene aberrations were evaluated by FISH and protein expressions by IHC. Neither HER2 overexpression nor HER2 gene amplification was observed in both tumor tissues and matched nontumor tissues. By contrast, TOP2A overexpression was detected in 72.5% of tumor tissues but not detected in matched nontumor tissues. However, TOP2A gene amplification was not observed in both tumor and matched nontumor tissues. TOP2A overexpression was significantly associated with HCC tumor tissues (P < 0.001), hepatitis B surface antigen (HBsAg) in the serum (P = 0.004), and Ki-67 (P = 0.038) but not with age, tumor size, alpha-fetoprotein, TP53, and copy number of TOP2A gene and chromosome 17 centromere. In conclusion, TOP2A overexpression in HCC was not secondary to gene amplification. In addition, neither HER2 amplification nor overexpression could be used as prognostic and predictive marker in HCC.

MicroRNA-484 is more highly expressed in serum of early breast cancer patients compared to healthy volunteers

Background

Previous studies have profiled breast cancer compared to normal breast tissue and identified differentially expressed microRNAs (miRNAs). These miRNAs are then assessed in serum of breast cancer patients compared to healthy volunteers. MiRNAs in serum however do not always reflect what is in tissue and important serum miRNAs may be missed. PCR arrays were therefore performed on serum samples from breast cancer patients compared to healthy volunteers with the aim of identifying circulating miRNAs that are more highly expressed in serum from early breast cancer patients compared to controls.

Methods

Taqman low density array (TLDA) cards were used to profile serum miRNAs in a discovery cohort of serum from 39 early breast cancer patients compared to 10 healthy volunteers. The results were confirmed in a validation cohort of serum from 98 early breast cancer patients compared to 25 healthy volunteers using customized qPCR plates.

Results

Seventeen miRNAs were found to have significantly higher levels in breast cancer serum compared to serum of healthy volunteers in the discovery cohort. Fourteen of these miRNAs were studied in the validation cohort and serum miR-484 was found to be at a significantly higher level in breast cancer serum compared to healthy volunteers.

Conclusion

In this study, we found that miR-484 is significantly differentially expressed in serum of early breast cancer patients compared to healthy volunteers. We did not however find any correlation between miR-484 levels with histopathological parameters of the breast cancers. With further studies, miR-484 may prove useful as an adjunct to mammography for detection of early breast cancer.

Predictive factors determining neoadjuvant chemotherapy outcomes in breast cancer - a single center experience

From January 1, 2008 to March 31, 2010, 101 patients with stage II-III breast cancer were enrolled in this study and subjected to an anthracycline-based neoadjuvant chemotherapy regimen with or without docetaxel. Surgery was performed after 2-6 cycles of chemotherapy, and the clinical response was determined by pathological and histochemical assessments. The clinical response rate, as indicated by complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD), were 6.9, 52.5, 36.6, and 4.0%, respectively. A multivariable correlation analysis indicated that the overall clinical response rate correlated with the number of metastatic lymph nodes, number of chemotherapy cycles, and vessel invasion status. Importantly, the CR rate was only associated with the number of chemotherapy cycles. Nonparametric tests failed to detect a correlation between HER2 or Topo IIα status and clinical response to neoadjuvant chemotherapy in these patients. When they were stratified by HER2 or HR status, for HER2-positive patients the CR rate was associated with vessel invasion and Topo IIα status. Based on our findings, we propose that HR, HER-2 and Topo IIα are not putative predictive biomarkers of chemotherapy outcome for breast cancer patients. Topo IIα expression level was only inversely correlated with CR rate among HR-positive patients. Importantly, the achievement of CR was largely related to the number of chemotherapy cycles.

Therapeutic strategies in male breast cancer: clinical implications of chromosome 17 gene alterations and molecular subtypes

Male breast cancer (MBC) is a rare disease. To date, therapy is mainly based on studies and clinical experiences with breast cancer in women. Only little is known about molecular typing of MBC, particularly with regard to potential biological predictors for adjuvant therapy. In female breast cancer tumors with chromosome 17 centromere (CEP17) duplication, HER2 and/or Topoisomerase II alpha (Topo II-α) gene alterations have been suggested to be associated with poor prognosis and increased sensitivity to anthracycline-containing regimens. In a well characterized cohort of 96 primary invasive MBC, we studied CEP17, HER2 and Topo II-α alterations by fluorescence in-situ hybridization (FISH), and expression of hormone receptors (HR), HER2 and Ki67 by immunohistochemistry to define molecular subtypes. Tumor characteristics and follow-up data were available and correlated with molecular findings. HER2 amplification and Topo II-α amplification/deletion were exceptionally rare in MBC (6.3% and 3.1%, respectively). CEP17 polysomy were found in 9.4% of tumors. HER2, Topo II-α and CEP17 gene alterations were not correlated to patients outcome. 96.9% of our cases were HR positive. Triple negative tumors were found in only 3.1% of the cases. In nodal negative tumors luminal A subtypes were significantly associated with better overall survival. Our results provide evidence for a predominant male breast cancer phenotype, characterized by HR expression and a lack of HER2/Topo II-α alterations and CEP17 duplicates. Therefore, the impact of anthracycline sensitivity linked to HER2/Topo II-α alterations as found in female breast cancer has low clinical significance for this specific male breast cancer phenotype.

A fourteen gene GBM prognostic signature identifies association of immune response pathway and mesenchymal subtype with high risk group

BACKGROUND

Recent research on glioblastoma (GBM) has focused on deducing gene signatures predicting prognosis. The present study evaluated the mRNA expression of selected genes and correlated with outcome to arrive at a prognostic gene signature.

METHODS

Patients with GBM (n = 123) were prospectively recruited, treated with a uniform protocol and followed up. Expression of 175 genes in GBM tissue was determined using qRT-PCR. A supervised principal component analysis followed by derivation of gene signature was performed. Independent validation of the signature was done using TCGA data. Gene Ontology and KEGG pathway analysis was carried out among patients from TCGA cohort.

RESULTS

A 14 gene signature was identified that predicted outcome in GBM. A weighted gene (WG) score was found to be an independent predictor of survival in multivariate analysis in the present cohort (HR = 2.507; B = 0.919; p<0.001) and in TCGA cohort. Risk stratification by standardized WG score classified patients into low and high risk predicting survival both in our cohort (p = <0.001) and TCGA cohort (p = 0.001). Pathway analysis using the most differentially regulated genes (n = 76) between the low and high risk groups revealed association of activated inflammatory/immune response pathways and mesenchymal subtype in the high risk group.

CONCLUSION

We have identified a 14 gene expression signature that can predict survival in GBM patients. A network analysis revealed activation of inflammatory response pathway specifically in high risk group. These findings may have implications in understanding of gliomagenesis, development of targeted therapies and selection of high risk cancer patients for alternate adjuvant therapies.

Investigation of CD28 gene polymorphisms in patients with sporadic breast cancer in a Chinese Han population in Northeast China

Background

CD28 is one of a number of costimulatory molecules that play crucial roles in immune regulation and homeostasis. Accumulating evidence indicates that immune factors influence breast carcinogenesis. To clarify the relationships between polymorphisms in the CD28 gene and breast carcinogenesis, a case-control study was conducted in women from Heilongjiang Province in northeast of China.

Methodology/Principal Findings

Our research subjects consisted of 565 female patients with sporadic breast cancer and 605 age- and sex-matched healthy controls. In total, 12 single nucleotide polymorphisms (SNPs) in the CD28 gene were successfully determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The relationship between the CD28 variants and clinical features, including histological grade, tumor size, lymph node metastasis, human epidermal growth factor receptor 2 (C-erbB2), estrogen receptor (ER), progesterone receptor (PR), and tumor protein 53 (P53) status were analyzed. A statistically significant association was observed between rs3116496 and breast cancer risk under different genetic models (additive P = 0.0164, dominant P = 0.0042). Different distributions of the rs3116496 ‘T’ allele were found in patients and controls, which remained significant after correcting the P value for multiple testing using Haploview with 10,000 permutations (corrected P = 0.0384). In addition, significant associations were observed between rs3116487/rs3116494 (D’ = 1, r² = 0.99) and clinicopathological features such as C-erbB2 and ER status, in breast cancer patients.

Conclusions/Significance

Our findings indicate that CD28 gene polymorphisms contribute to sporadic breast cancer risk and have a significant association with clinicopathological features in a northeast Chinese Han population.

Multiplication of Chromosome 17 Centromere Is Associated with Prognosis in Patients with Invasive Breast Cancers Exhibiting Normal HER2 and TOP2A Status

PURPOSE

This study aimed to investigate the clinical significance of chromosome 17 centromere (CEP17) multiplication (increased copy number of CEP17) related to human epidermal growth factor receptor 2 (HER2) and topoisomerase II alpha (TOP2A) status in patients with invasive breast cancer.

METHODS

We constructed tissue microarrays using 594 invasive breast cancer samples and performed single-color silver-enhanced in situ hybridization (SISH) assay for HER2, TOP2A, and CEP17 to assess for copy number aberrations. The association of CEP17 multiplication with patient survival was analyzed according to HER2 and TOP2A status.

RESULTS

Among 567 informative cases, HER2 amplification was noted in 22.8%, TOP2A amplification in 8.3% and TOP2A deletion in 11.1%. CEP17 multiplication was identified in 33.2% and was significantly associated with worse overall survival (OS) (p=0.02) and disease-free survival (DFS) (p=0.02). CEP17 multiplication correlated with patient survival in patients with normal TOP2A or non-amplified HER2 status, but the prognostic significance was lost in those with altered TOP2A or amplified HER2. On multivariate analyses, CEP17 multiplication was an independent prognostic factor for poorer OS (p=0.02) and DFS (p=0.01) in patients with normal TOP2A and non-amplified HER2.

CONCLUSION

CEP17 multiplication was identified as a promising prognostic marker in patients with invasive breast cancer exhibiting either non-amplified HER2 or normal TOP2A status.

Prognostic value of TOP2A gene amplification and chromosome 17 polysomy in early breast cancer

The aim of this study was to analyze the occurrence of TOP2A gene amplification and chromosome 17 polysomy in patients with early breast cancer and to correlate the status of these alterations with the prognostic significance expressed as patients' clinical features and survival. Such concurrent analyses of TOP2A gene status and chromosome 17 polysomy have not been performed before. Study group included 149 consecutive stage I-III patients administered standard multimodality treatment. TOP2A abnormalities were examined by standard fluorescence in situ hybridization (FISH) and developed by our group quantitative real-time PCR (qPCR). TOP2A amplification and deletion assessed by FISH were found in 23% and 7% of the tumours, respectively, and by qPCR in 31% and 11% of the tumours, respectively. Chromosome 17 polysomy was detected in 40% of the cases. TOP2A amplification (by qPCR) correlated with shorter disease-free survival (p = 0.03) and overall survival (p = 0.047), and the prognostic value of TOP2A was confirmed in the multivariate analysis (HR = 3.22, 95% CI 1.09-9.56, p = 0.03). TOP2A gene amplification, but not chromosome 17 polysomy, carries negative prognostic information in early breast cancer. Given the aforementioned results, qPCR might serve as a prognostic tool in determining the patient's prognosis.

A human Fab-based immunoconjugate specific for the LMP1 extracellular domain inhibits nasopharyngeal carcinoma growth in vitro and in vivo

Nasopharyngeal carcinoma (NPC) is a major cause of cancer-related death in Southeast Asia and China. Metastasis and relapse are the primary cause of morbidity and mortality in NPC. Recent evidence suggests that the Epstein-Barr virus latent membrane protein 1 (LMP1) is exclusively expressed in most NPC and is a potential target for biotherapy. In this study, we successfully prepared a novel human antibody Fab (HLEAFab) against LMP1 extracellular domain, which was subsequently conjugated with mitomycin C (MMC), thus forming an immunoconjugate (HLEAFab-MMC). The effects of HLEAFab-MMC on proliferation and apoptosis in NPC cell lines HNE2/LMP1 and the inhibition rate of growth of NPC xenografts in nude mice were examined. The inhibition rate of HNE2/LMP1 cell proliferation was the highest for HLEAFab-MMC (76%) compared with MMC (31%) and HLEAFab (22%) at a concentration of 200 nmol/L and showed dose-dependent fashion. The apoptosis rate of HNE2/LMP1 cell lines was 13.88% in HLEAFab-MMC group, 3.04% in MMC group, 2.78% in HLEAFab group, and 2.10% in negative control group at the same concentration, respectively. In vivo, the inhibition rate of growth of NPC xenografts in nude mice was 55.1% in HLEAFab-MMC group, 26.5% in MMC group, and 5.64% in HLEAFab group. In summary, our findings show that HLEAFab-MMC is a unique immunoconjugate with the potential as a novel therapeutic agent in the treatment of LMP1-expressing NPC.

Tumor topoisomerase II alpha status and response to anthracycline-based neoadjuvant chemotherapy in breast cancer

OBJECTIVES

Individualized chemotherapy for breast cancer improves the outcome. Anthracyclines target the enzyme topoisomerase IIα (TOP2A). We set out to perform a retrospective study of the presence of gene abnormalities and the expression of TOP2A in a cohort of breast cancer patients treated with neoadjuvant anthracycline-based chemotherapy.

METHODS

Forty-three patients with 45 breast cancers were treated with neoadjuvant docetaxel-epirubicin with/without capecitabine chemotherapy. The TOP2A status of the cancers, determined retrospectively by fluorescent in situ hybridization and immunohistochemistry, was analyzed in relation to the standard clinical and pathological data.

RESULTS

Clinically and pathologically complete remission (pCR) was achieved in 15 (33.3%) and 9 (20%) cases, respectively. The TOP2A gene was amplified in 2 human epidermal growth factor receptor 2 (HER2)-positive cancers (8%), and 32 (84.2%) overall exhibited TOP2A expression in >15% of the cells. The expression of TOP2A exhibited a strong correlation with the expression of Ki67 (R = 0.743, p < 0.001), and was negatively correlated with estrogen receptors (ER; R = 0.404, p = 0.012) and progesterone receptors (R = 0.430, p = 0.007). The expression of TOP2A was not related to the amplification of the TOP2A gene or the HER2 status of the tumor. The proportions of Ki67- and TOP2A-positive tumor cells were significantly reduced after chemotherapy (56.1 ± 23.6 vs. 19.0 ± 27.7%, p = 0.004, and 41.0 ± 27.9 vs. 12.7 ± 24.8%, p < 0.001, respectively). The development of pCR was related to a high grade (p = 0.054), ER negativity (p = 0.027) and high TOP2A expression (p = 0.037). The expression of TOP2A was an independent predictor of pCR (OR = 1.460, for every 10% increase, 95% CI: 1.016-2.096, p = 0.041). After a median follow-up time of 31.0 months, neither relapse-free survival nor overall survival was related to the tumor response.

CONCLUSIONS

TOP2A expression is a marker of the tumor's proliferation rate and sensitivity to anthracycline-based chemotherapy, and does not depend on the amplification of its gene.

Tumour topoisomerase II alpha protein expression and outcome after adjuvant dose-dense anthracycline-based chemotherapy

There is a need for the selection of those breast cancers where benefit may be attained from the addition of an anthracycline to the adjuvant chemotherapy. The expression of topoisomerase II alpha (TOP2A) protein in 3 cohorts of breast cancers treated with adjuvant dose-dense anthracycline-based chemotherapy was determined retrospectively. The TOP2A status was analysed in relation with the other standard tumour features and the outcome. TOP2A IHC results were assessable in 106 patients: with a cut-off value of 15%, 48% of the tumours were classified as TOP2A-positive. The expression of TOP2A correlated with that of Ki67 (R = 0.532, p < 0.001) and a high grade (p = 0.04), but did not correlate with the proportion of ER- or PR-positive cells in the tumour. More tumors were TOP2A-negative among the ER- or PR-positive cancers than among the ER/PR-negative cancers (p = 0.021 and p = 0.002, respectively). After a median follow-up time of 64.5 months, 31 relapses (23.5%) and 23 deaths (17.4%) had occurred in 131 patients. The overall survival was longer in the TOP2A-positive cases than in the TOP2A-negative cases. The recurrence-free survival and the overall survival were significantly more favourable in the ER/PR-negative and TOP2A-positive tumours than in other subgroups. In a Cox proportional hazards model, the grade and TOP2A remained significant determinants in the ER/PR-negative subgroup. TOP2A positivity and grade 3 indicated a decrease in the risk of death with HR = 0.211 (95% CI: 0.042-1.05, p = 0.056) and HR = 0.216 (95% CI: 0.047-0.990, p = 0.048), respectively. A higher sensitivity to anthracycline-containing regimens is suggested in ER/PR-negative and TOP2A-positive cancers.

GPHMM: an integrated hidden Markov model for identification of copy number alteration and loss of heterozygosity in complex tumor samples using whole genome SNP arrays

There is an increasing interest in using single nucleotide polymorphism (SNP) genotyping arrays for profiling chromosomal rearrangements in tumors, as they allow simultaneous detection of copy number and loss of heterozygosity with high resolution. Critical issues such as signal baseline shift due to aneuploidy, normal cell contamination, and the presence of GC content bias have been reported to dramatically alter SNP array signals and complicate accurate identification of aberrations in cancer genomes. To address these issues, we propose a novel Global Parameter Hidden Markov Model (GPHMM) to unravel tangled genotyping data generated from tumor samples. In contrast to other HMM methods, a distinct feature of GPHMM is that the issues mentioned above are quantitatively modeled by global parameters and integrated within the statistical framework. We developed an efficient EM algorithm for parameter estimation. We evaluated performance on three data sets and show that GPHMM can correctly identify chromosomal aberrations in tumor samples containing as few as 10% cancer cells. Furthermore, we demonstrated that the estimation of global parameters in GPHMM provides information about the biological characteristics of tumor samples and the quality of genotyping signal from SNP array experiments, which is helpful for data quality control and outlier detection in cohort studies.

Alteration of topoisomerase II-alpha gene in human breast cancer: association with responsiveness to anthracycline-based chemotherapy

PURPOSE

Approximately 35% of HER2-amplified breast cancers have coamplification of the topoisomerase II-alpha (TOP2A) gene encoding an enzyme that is a major target of anthracyclines. This study was designed to evaluate whether TOP2A gene alterations may predict incremental responsiveness to anthracyclines in some breast cancers.

METHODS

A total of 4,943 breast cancers were analyzed for alterations in TOP2A and HER2. Primary tumor tissues from patients with metastatic breast cancer treated in a trial of chemotherapy plus/minus trastuzumab were studied for amplification/deletion of TOP2A and HER2 as a test set followed by evaluation of malignancies from two separate, large trials for changes in these same genes as a validation set. Association between these alterations and clinical outcomes was determined.

RESULTS

Test set cases containing HER2 amplification treated with doxorubicin and cyclophosphamide (AC) plus trastuzumab, demonstrated longer progression-free survival compared to those treated with AC alone (P = .0002). However, patients treated with AC alone whose tumors contain HER2/TOP2A coamplification experienced a similar improvement in survival (P = .004). Conversely, for patients treated with paclitaxel, HER2/TOP2A coamplification was not associated with improved outcomes. These observations were confirmed in a larger validation set, where HER2/TOP2A coamplification was again associated with longer survival when only anthracycline-containing chemotherapy was used for treatment compared with outcome in HER2-positive cancers lacking TOP2A coamplification.

CONCLUSION

In a study involving nearly 5,000 breast malignancies, both test set and validation set demonstrate that TOP2A coamplification, not HER2 amplification, is the clinically useful predictive marker of an incremental response to anthracycline-based chemotherapy. Absence of HER2/TOP2A coamplification may indicate a more restricted efficacy advantage for breast cancers than previously thought.

A human recombinant autoantibody-based immunotoxin specific for the fetal acetylcholine receptor inhibits rhabdomyosarcoma growth in vitro and in a murine transplantation model

Rhabdomyosarcoma (RMS) is the most common malignant soft tissue tumor in children and is highly resistant to all forms of treatment currently available once metastasis or relapse has commenced. As it has recently been determined that the acetylcholine receptor (AChR) gamma-subunit, which defines the fetal AChR (fAChR) isoform, is almost exclusively expressed in RMS post partum, we recombinantly fused a single chain variable fragment (scFv) derived from a fully human anti-fAChR Fab-fragment to Pseudomonas exotoxin A to generate an anti-fAChR immunotoxin (scFv35-ETA). While scFv35-ETA had no damaging effect on fAChR-negative control cell lines, it killed human embryonic and alveolar RMS cell lines in vitro and delayed RMS development in a murine transplantation model. These results indicate that scFv35-ETA may be a valuable new therapeutic tool as well as a relevant step towards the development of a fully human immunotoxin directed against RMS. Moreover, as approximately 20% of metastatic malignant melanomas (MMs) display rhabdoid features including the expression of fAChR, the immunotoxin we developed may also prove to be of significant use in the treatment of these more common and most often fatal neoplasms.

Topoisomerase IIalpha expression rather than gene amplification predicts responsiveness of adjuvant anthracycline-based chemotherapy in women with primary breast cancer

INTRODUCTION

Adjuvant anthracycline-based chemotherapy (AbCTX) is a standard treatment for patients with primary breast cancer. Its main target is topoisomerase IIalpha (TopIIa), a nuclear protein which is important for DNA replication and mitosis. We propose that the overexpression of the TopIIa protein or amplification of the TopIIa gene may be useful in predicting increased responsiveness towards AbCTX.

METHODS

Tumor tissues of 118 patients who received adjuvant AbCTX were examined by immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH) for TopIIa and HER2. For IHC, the primary antibodies 485 (Dako) and NCL-TOPOIIA (Novocastra) were used. FISH analysis was performed with the SPEC HER2/CEP 17 Dual Color Probe (Zytovision) and LSI TOP 2A Spectrum Orange/CEP 17 Spectrum Green probe (Abbott). TopIIa IHC was evaluated by the immunoreactive score (IRS). FISH amplification was stated at an HER2-TopIIa/CEP 17 ratio > or = 2, deletion of TopIIa at a ratio <0.8.

RESULTS

The median age of the patient population was 50 years (range 23-77), 76 (64%) had tumors >2 cm in size, 98 (85%) were nodal positive, and 72 (66%) estrogen-receptor positive. Chemotherapy regimes consisted of epirubicin-cyclophosphamide (EC 40 pts), EC-CMF (18 pts), FAC/FEC (33 pts), anthracycline-taxane combinations (23 pts) and others (4 pts). After IHC, it was found that 19% of the tumors were positive for HER2 (3+) and the median IRS for TopIIa staining was 2 (49% positive); 28 (24%) tumors showed HER2 amplification, therefrom 20/22 (91%) within the HER2 3+ group. TopIIa gene was amplified in 17 cases (16%) and deletion was seen in 6 (5%) tumors. Of all cases with HER2 gene amplification, 14 (50%) cases of TopIIa co-amplification and one case of deletion were seen. Looking at histological parameters, TopIIa IHC correlated with nodal status (P = 0.018) and high grading (G3) (P = 0.047). After a median follow-up of 42 months (range 1-242), a significant prognostic factor for local recurrence was HER2 positivity (IHC P = 0.013 and FISH P = 0.023). Thirty-two patients developed metastasis (27%), which was correlated with HER2 FISH positivity (P = 0.024) and, as a trend, Top IIa IHC negativity (P = 0.094); 25 (21%) patients died from the disease. Negative prognostic parameters were the lack of estrogen-receptor expression (P = 0.008), lymphangiosis (P = 0.02), and TopIIa IHC negativity (P = 0.03).

CONCLUSION

In this cohort of patients, HER2 positivity indicated higher rates of local and distant recurrence. In contrast, TopIIa IHC positivity predicted lower risk of metastases and death, thus being a positive-predictive factor for the responsiveness to AbCTX. TopIIa gene amplification did not add predictive information. Therefore, we conclude that TopIIa protein expression might rather be the target of anthracyclines independent from gene copy number.

The role of topoisomerase IIalpha and HER-2 in predicting sensitivity to anthracyclines in breast cancer patients

Human epidermal growth factor receptor-2 (HER-2) and topoisomerase IIalpha (topo IIalpha) co-inhabit chromosome 17. In the search for predictive biomarkers to refine clinical prescription of cytotoxic agents, both HER-2 and topo IIalpha are under exploration for their potential role in identifying individuals with early breast cancer who may benefit from anthracycline therapy. Whilst recent meta-analyses support a predictive role for HER-2 amplification, it remains unclear whether HER-2 is the critical biomarker or whether it is a surrogate marker for topo IIalpha alteration, a known drug target of anthracyclines. The major limitation in considering HER-2 as a single marker is heterogeneity within the subgroups of HER-2 positive and HER-2 negative disease. For topo IIalpha, current data is inconclusive. Issues plaguing this field are technical variability in marker definition, complex regulation pathway of topo IIalpha and lack of prospective, adequately powered studies. With current evidence, neither HER-2 nor topo IIalpha gene status can be considered clinically valuable markers for anthracycline benefit. This paper will focus on issues relating to reliable detection and predictive analyses of HER-2 and topo IIalpha, and highlight potential developments in improving individualized approach to anthracycline use in early breast cancer patients.

Breast cancer and aneusomy 17: implications for carcinogenesis and therapeutic response

Abnormalities of chromosome 17, recognised over two decades ago to be important in tumorigenesis, often occur in breast cancer. Changes of specific loci on chromosome 17 including ERBB2 amplification, P53 loss, BRCA1 loss, and TOP2A amplification or deletion are known to have important roles in breast-cancer pathophysiology. Numerical aberrations of chromosome 17 are linked to breast-cancer initiation and progression, and possibly to treatment response. However, the clinical importance of chromosome 17 anomalies, in particular the effect on ERBB2 protein expression, is unknown. Reports are conflicting regarding the association of copy gain of chromosome 17 (polysomy 17) with strong ERBB2 protein expression in the absence of true ERBB2 gene amplification. Copy-number anomalies in chromosome 17 seem to be common in tumours that show discrepant ERBB2 expression and in tumours with discordant ERBB2-protein and ERBB2 gene copy number measurements. The mechanisms of ERBB2 dosage changes-gene amplification versus chromosome gain and loss-probably differ in primary and metastatic disease; however, a correction for chromosome 17 copy-number is necessary to completely distinguish between these mechanisms. A better understanding of how polysomy 17 affects gene-copy number and protein expression will help to select patients who will respond to therapies targeting ERBB2 and other protein products of chromosome 17 loci.

Solamargine induces apoptosis and enhances susceptibility to trastuzumab and epirubicin in breast cancer cells with low or high expression levels of HER2/neu

Trastuzumab is used for breast cancer patients with high expression levels of HER2 (human epidermal growth factor receptor 2)/neu; however, it has no effect on cancers with low levels of HER2/neu. SM (solamargine), a major steroidal alkaloid glycoside purified from Solanum incanum, triggered apoptosis of breast cancer cells (MCF-7 and SK-BR-3 cells) and non-cancerous breast epithelial cells (HBL-100 cells) within 3 h. To extend the application of trastuzumab in breast cancer patients, the regulation of HER2/neu expression by SM was investigated. SM significantly up-regulates HER2/neu expression in breast cancer cells with low and high expression levels of HER2/neu, and synergistically enhanced the effect of trastuzumab in inhibiting cell proliferation. Additionally, HER2/neu and TOP2A [TopoII (topoisomerase II) α] genes share the same amplicon on an identical chromosome. Notably, SM co-regulates HER2/neu and TopoIIα expression markedly, and enhances TopoII inhibitor–EPI (epirubicin)-induced cytotoxicity to breast cancer cells.

Facts and controversies in the use of trastuzumab in the adjuvant setting

The human epidermal growth factor receptor-2 (HER2) is overexpressed and/or amplified in up to 25% of breast cancer patients, and this feature is associated with an aggressive phenotype, high recurrence rate and reduced survival. Until recently, combination chemotherapy (with or without endocrine therapy) was the only effective adjuvant treatment for HER2-positive patients. Trastuzumab is a monoclonal antibody directed against the HER2 extracellular domain, and five recent adjuvant breast cancer trials have demonstrated an astonishing and highly reproducible benefit in halving the recurrence rate and reducing mortality in patients with this phenotype. Many questions related to trastuzumab use in the adjuvant setting still remain; these include the optimum timing and duration of treatment, trastuzumab use with taxanes and radiotherapy, its role in small node-negative tumors, the optimum chemotherapy regimens and cost-effectiveness. This Review outlines the five adjuvant trastuzumab studies and discusses the controversies and challenges that have emerged for both the clinician and healthcare authorities worldwide as a consequence of the results from these trials.

Topoisomerase II alpha gene copy loss has adverse prognostic significance in ERBB2-amplified breast cancer: a retrospective study of paraffin-embedded tumor specimens and medical charts

BACKGROUND

Amplification of the ERBB2 (Her-2/neu) oncogene, which occurs in approximately 25% of breast carcinomas, is a known negative prognostic factor. Available data indicate that a variable number of nearby genes on chromosome 17q may be co-amplified or deleted, forming a continuous amplicon of variable size. In approximately 25% of these patients, the amplicon extends to the gene for topoisomerase II alpha (TOP2A), a target for anthracyclines. We sought to understand the significance of these associated genomic changes for breast cancer prognosis and predicting response to therapy.

METHODS AND PATIENTS

Archival tissue samples from 63 breast cancer patients with ERBB2 amplification, stages 0-IV, were previously analyzed with FISH probes for genes located near ERBB2. In the present study, the clinical outcome data were determined for all patients presenting at stages I-III for whom adequate clinical follow up was available.

RESULTS

Four amplicon patterns (Classes) were identified. These were significantly associated with the clinical outcome, specifically, recurrence of breast cancer. The Amplicon class IV with deleted TOP2A had 67% (6/9) cases with recurrence, whereas the other three classes combined had only 12% (3/25) cases (p-value = 0.004) at the time of last follow-up. TOP2A deletion was also significantly associated with time to recurrence (p-value = 0.0002). After adjusting for age in Cox regression analysis, the association between TOP2A deletion and time to recurrence remains strongly significant (p-value = 0.002) whereas the association with survival is marginally significant (p-value = 0.06).

CONCLUSION

TOP2A deletion is associated with poor prognosis in ERBB2-amplified breast carcinomas. Clarification of the mechanism of this association will require additional study.

Influence of activation state of ErbB-2 (HER-2) on response to adjuvant cyclophosphamide, doxorubicin, and fluorouracil for stage II, node-positive breast cancer: study 8541 from the Cancer and Leukemia Group B

PURPOSE

ErbB-2 (human epidermal growth factor receptor 2) overexpression may be predictive of relative resistance and/or sensitivity to specific chemotherapeutic agents. Results from a previous study from the Cancer and Leukemia Group B (CALGB 8541) demonstrated an interaction between ErbB-2 and increasing dose of adjuvant cyclophosphamide, doxorubicin, and fluorouracil (CAF) chemotherapy. Other studies have suggested that evaluation of the phosphorylated/activated form of ErbB-2 might be more precise in defining the impact of ErbB-2 in breast cancer. We have evaluated tumor tissue sections from CALGB 8541 patients to determine whether the interaction of ErbB-2 with CAF dose is dependent on ErbB-2 activation state, and whether phosphorylated ErbB-2 is an adverse prognostic factor in patients treated with CAF.

PATIENTS AND METHODS

Patients were randomly assigned to one of three dosing regimens of CAF. Paraffin samples from 992 of 1,572 patients who participated in CALGB 8541 were available. Of the 570 tumors with any staining for ErbB-2, 488 had tissue available for assay for phosphorylated ErbB-2, which was performed by immunohistochemistry.

RESULTS

Of 910 total assessable cases, 112 of 488 ErbB-2-positive cases (23%) stained positively for phosphorylated ErbB-2. The previously described interaction of dosing regimen of CAF with ErbB-2 was not dependent on phosphorylation status of ErbB-2.

CONCLUSION

Monitoring phosphorylation of ErbB-2 with an antiphospho-ErbB-2 antibody did not add further precision to identifying those patients most likely to benefit from increased dose of anthracycline-based adjuvant chemotherapy. Favorable outcomes are observed in ErbB-2-overexpressing patients treated with high-dose CAF regardless of ErbB-2 phosphorylation state.

Phenotypic and genetic characterization of circulating tumor cells by combining immunomagnetic selection and FICTION techniques

The presence of circulating tumor cells (CTCs) in breast cancer patients has been proven to have clinical relevance. Cytogenetic characterization of these cells could have crucial relevance for targeted cancer therapies. We developed a method that combines an immunomagnetic selection of CTCs from peripheral blood with the fluorescence immunophenotyping and interphase cytogenetics as a tool for investigation of neoplasm (FICTION) technique. Briefly, peripheral blood (10 ml) from healthy donors was spiked with a predetermined number of human breast cancer cells. Nucleated cells were separated by double density gradient centrifugation of blood samples. Tumor cells (TCs) were immunomagnetically isolated with an anti-cytokeratin antibody and placed onto slides for FICTION analysis. For immunophenotyping and genetic characterization of TCs, a mixture of primary monoclonal anti-pancytokeratin antibodies was used, followed by fluorescent secondary antibodies, and finally hybridized with a TOP2A/HER-2/CEP17 multicolor probe. Our results show that TCs can be efficiently isolated from peripheral blood and characterized by FICTION. Because genetic amplification of TOP2A and ErbB2 (HER-2) in breast cancer correlates with response to anthracyclines and herceptin therapies, respectively, this novel methodology could be useful for a better classification of patients according to the genetic alterations of CTCs and for the application of targeted therapies.

Therapy Insight: anthracyclines and trastuzumab--the optimal management of cardiotoxic side effects

Anthracyclines and trastuzumab are key agents in the management of patients with breast cancer, and have revolutionized the management of both early-stage and advanced-stage disease. The use of anthracyclines, however, can be compromised by the potential for cardiotoxicity; trastuzumab also has the potential for causing cardiotoxicity in patients receiving concurrent or prior anthracyclines. Although its development is treatment limiting, cardiotoxicity can be minimized with appropriate clinical care and drug scheduling. We discuss the efficacy of trastuzumab, its potential for cardiac compromise, and its interaction with anthracyclines. We highlight biological mechanisms that might be responsible for cardiotoxicity, describe the established and trial schedules of both agents, and discuss clinical strategies used to minimize the risk of developing cardiac failure through appropriate scheduling of trastuzumab with anthracyclines.

Downregulation of HER2/neu receptor by solamargine enhances anticancer drug-mediated cytotoxicity in breast cancer cells with high-expressing HER2/neu

Overexpression of HER2/neu is associated with drug resistance and poor outcome in breast cancer. Solamargine (SM), a glycoalkaloid purified from the herb Solanum incanum, exhibits HER2/neu gene modulation of HER2/neu high-expressing human breast cancer cell line ZR-75-1. SM downregulation of HER2/neu gene expression was determined by RT-PCR and Southern hybridization. Additionally, the membrane-bound HER2/neu receptor in highly HER2/neu-expressing breast cancer cells was determined by radioimmunoassay, immunocytochemistry, fluorescent immunocytochemistry, and flow cytometry. SM significantly decreased the number of HER2/neu receptors on the cell membrane. Methotrexate (MTX), 5-florouracil (5-Fu), and cisplatin (CDDP) are commonly used for breast carcinoma treatment in clinics; however, patients with HER2/neu overexpression exhibit resistance to these anticancer drugs. Notably, combination of MTX, 5-Fu, and CDDP with SM individually increased the susceptibility of breast cancer cells to these chemotherapeutic agents. Experimental results indicated that downregulation of HER2/neu by SM might be an effective strategy for enhancing drug susceptibility of breast cancer cells expressing high levels of HER2/neu.

Does polysomy of chromosome 17 have a role in ERBB2 and topoisomerase IIalpha expression? Gene, mRNA and protein expression: a comprehensive analysis

OBJECTIVES

ERBB2 is an oncogene with prognostic and predictive value. Topoisomerase IIalpha is an enzyme encoding close to the ERBB2 oncogene, that represents a molecular target for anthracyclines. An indirect mechanism of increasing ERBB2 and topoisomerase IIalpha gene copy number is chromosome 17 polysomy. The aim of the present study was to clarify the implication of polysomy 17 in ERBB2 and topoisomerase IIalpha expression. In addition, we assessed the relation of ERBB2 and topoisomerase IIalpha gene dosage to mRNA and protein levels.

METHODS

We selected 83 cases diagnosed as invasive breast cancer. We analysed ERBB2 and topoisomerase IIalpha genes, mRNA and protein by fluorescence in situ hybridisation, real-time reverse-transcription polymerase chain reaction and immunohistochemistry.

RESULTS

We observed a progressive increase in mRNA expression from 0+ to 3+ and also a significant difference in the ERBB2 RNA levels between normal and amplified cases. We found that polysomy of chromosome 17 does not affect the ERBB2 expression and that topoisomerase IIalpha mRNA expression is not related to gene status.

CONCLUSIONS

Our results demonstrate that polysomy of chromosome 17 is not related to ERBB2 expression. Thereby, it is important to use centromeric probes to clearly discriminate between true ERBB2 gene amplification and polysomy of chromosome 17.

Chromogenic and fluorescent in situ hybridization in breast cancer

Fluorescent (FISH) and chromogenic (CISH) in situ hybridization have recently become part of the diagnostic armamentarium of breast pathologists. HER2 gene testing by FISH and/or CISH has become an integral part of the diagnostic workup for patients with breast cancer. In this era of high throughput technologies, these techniques have proven instrumental for the validation of results from microarray-based comparative genomic hybridization and for the identification of novel oncogenes and tumor suppressor genes. Furthermore, FISH and CISH applied to tissue microarrays have expedited the characterization of genomic changes associated with specific breast cancer molecular subtypes and the identification of novel prognostic and predictive markers. In this review, we provide in this review a critical assessment of CISH and FISH and the impact of the analysis of amplification of specific oncogenes (eg, HER2, EGFR, MYC, CCND1, and FGFR1) and deletion of tumor suppressor genes (eg, BRCA1 and BRCA2) on our understanding of breast cancer.

Effect of structural modification at the 4, 3', and 2' positions of doxorubicin on topoisomerase II poisoning, apoptosis, and cytotoxicity in human melanoma cells

Introduction:

The mechanism of the cytotoxicity of anthracyclines is pleiotropic and its significance in cell growth inhibition seems to be highly specific and dependent on cell type and anthracycline drug. Resistance and the high cardiotoxicity of anthracyclines have stimulated many studies aimed at identifying critical substituents required for optimal activity. Many authors point to the fact that the double-strand breaks, the consequence of the activity of topoisomerase II poisons, and the inability of cells to repair the DNA lesions are the signal for apoptosis. The aim of this study was to define the influence of 4-demetoxy 2′-halogenated analogs with altered basicity at the 3′-position on topoisomerase II and the relationship of that interaction with apoptosis and the cytotoxicity of these novel anthracyclines. Parental human ME18 melanoma cells and the ME18/R subline, obtained experimentally, resistant to doxorubicin (DOX), exposed to 1.7 and 8.6 µM DOX or its analogs, annamycin and WP903 (both 0.3 and 3.0 µM) were studied.

Materials and Methods:

The MTT test was used to assay cytotoxicity. Interaction of the drugs with topoisomerase II and apoptosis were done by Western blot and fluorescence microscopy using Hoechst 33342.

Results:

The structural changes at positions 4, 2′, and 3′ can influence topoisomerase II interaction and apoptotic activity, although correlation between these events and cytotoxic consequences has not been proved.

Conclusions:

The biological response of the cells to the structurally similar anthracyclines may be variable and probably depends on the cell type which seems to be an additional problem in the multifactorial resistance of tumor cells to anthracyclines.

Topoisomerase II Alpha Expression in Testicular Germ Cell Tumors

OBJECTIVES

Inhibitors of topoisomerase II alpha (TopoIIalpha), an enzyme with a crucial role in DNA maintenance, are included in the chemotherapy protocols for testicular germ cell tumors (GCTs). Despite the success of current chemotherapy regimens, a significant number of patients experience relapse. We analyzed TopoIIalpha expression in primary and metastatic testicular GCTs because this enzyme is a target for some antineoplastic agents.

METHODS

Primary GCT specimens from 109 patients, including 57 seminomas and 52 mixed GCTs (41 embryonal carcinomas, 23 yolk sac tumors, 19 seminomas, 8 choriocarcinomas, 17 teratomas with immature elements, and 16 teratomas with mature elements), were obtained from our archives. The metastatic lesions from 11 of the patients with mixed GCTs included seven teratomas with mature components, five embryonal carcinomas, one yolk sac tumor, one choriocarcinoma, and one teratoma with immature components. Representative sections were subjected to immunohistochemistry with monoclonal antibody against TopoIIalpha, and the nuclear staining findings were evaluated.

RESULTS

Most embryonal carcinoma (100%), yolk sac tumor (95%), seminoma (88%), and choriocarcinoma (62%) components of the GCTs were TopoIIalpha immunoreactive. None of the teratoma specimens with mature elements expressed TopoIIalpha.

CONCLUSIONS

The results of our study have shown that TopoIIalpha is expressed in most seminomas, embryonal carcinomas, yolk sac tumors, and choriocarcinomas, suggesting a possible mechanism of sensitivity of these components to TopoIIalpha inhibitors. Teratomas with mature and immature elements expressed low levels of TopoIIalpha, which might contribute to their chemoresistance. These findings imply that the variable chemoresponsiveness of testicular GCTs could have an underlying molecular basis.

TOP2A and HER2 gene amplification as predictors of response to anthracycline treatment in breast cancer

The purpose of this study was to evaluate amplification of topoisomerase IIalpha (TOP2A) and HER2 genes as predictors of response to chemotherapy in advanced breast cancer. Gene copy number of TOP2A and HER2 were analysed with chromogenic in situ hybridization (CISH) on paraffin-embedded tissue sections from the primary tumour of 85 patients treated with anthracycline containing chemotherapy. TOP2A gene amplification was present in 14 (16%) and HER2 gene amplification in 38 (45%) of the primary tumours. Two of the 14 cases with TOP2A amplification were amplified without concurrent HER2 amplification. Neither TOP2A nor HER2 gene amplification were significantly associated with response to chemotherapy (p = 0.35 and p = 0.49, respectively).

Novel patterns of genome rearrangement and their association with survival in breast cancer

Representational Oligonucleotide Microarray Analysis (ROMA) detects genomic amplifications and deletions with boundaries defined at a resolution of approximately 50 kb. We have used this technique to examine 243 breast tumors from two separate studies for which detailed clinical data were available. The very high resolution of this technology has enabled us to identify three characteristic patterns of genomic copy number variation in diploid tumors and to measure correlations with patient survival. One of these patterns is characterized by multiple closely spaced amplicons, or "firestorms," limited to single chromosome arms. These multiple amplifications are highly correlated with aggressive disease and poor survival even when the rest of the genome is relatively quiet. Analysis of a selected subset of clinical material suggests that a simple genomic calculation, based on the number and proximity of genomic alterations, correlates with life-table estimates of the probability of overall survival in patients with primary breast cancer. Based on this sample, we generate the working hypothesis that copy number profiling might provide information useful in making clinical decisions, especially regarding the use or not of systemic therapies (hormonal therapy, chemotherapy), in the management of operable primary breast cancer with ostensibly good prognosis, for example, small, node-negative, hormone-receptor-positive diploid cases.

The 17q12-q21 amplicon: Her2 and topoisomerase-IIalpha and their importance to the biology of solid tumours

Her2 and topoisomerase-IIalpha (T2A) gene amplification are separate events, although the latter is more frequently seen in Her2 amplified (34-90%) than in Her2 non-amplified (5-10%) tumours. There is a better correlation between Her2 amplification and protein overexpression in breast cancer (BC) than in other tumour types. This marker is also considered a powerful prognostic factor in BC, with similar data emerging in other solid tumours such as bladder, ovarian, endometrial, gastro-oesophageal and non-small cell lung cancer. Her2 amplification and/or overexpression are highly predictive of response to HER2-targeted compounds such as trastuzumab and lapatinib but have been inconsistent predictors of response to cytotoxic chemotherapy. There is also evidence that these tumours are relatively resistant to anti-oestrogen therapy (tamoxifen) but not to oestrogen deprivation (e.g. with aromatase inhibitors). T2A aberrations are uncommon events in solid tumours, with an overall prevalence of approximately 10%. T2A amplification has shown inconsistent correlation with T2A protein expression in preclinical and clinical studies, mainly because non-genetic events such as proliferation rate can also affect protein expression. Expression of T2A protein has not been shown to reliably predict response to T2A inhibitors, despite the fact that this enzyme is the direct target for these compounds. In BC, T2A amplification appears to be a good predictor of response to anthracyclines, but these data are still in the process of validation. The significance of T2A deletions is currently under investigation, but contrary to what was previously thought, it may also predict benefit from treatment with T2A inhibitors. The prognostic significance of T2A aberrations is currently unknown.

Adjuvant Therapy with Trastuzumab for HER‐2/neu‐Positive Breast Cancer

Breast cancer is the most common cancer in women in the U.S. and western Europe. Amplification of the her-2/neu gene occurs in approximately 25% of invasive ductal carcinomas of the breast. In experimental models, transfection of the her-2/neu gene results in transformation of mammary epithelial cells. In human breast cancer, amplification of the her-2/neu gene results in protein over expression and poor prognosis. Patients whose tumors have her-2/neu gene amplification have a shorter disease-free survival time than patients whose tumors exhibit a normal her-2/neu gene copy number. her-2/ neu gene amplification identifies a biologically unique subset of aggressive breast tumors that are sensitive to growth inhibition and apoptosis induced by anti-HER-2/neu-targeted therapies. The first HER-2/neu-targeted approach to reach the clinic was trastuzumab, a humanized monoclonal antibody directed against the extracellular domain of the HER-2/neu protein. Trastuzumab therapy prolongs the survival of patients with metastatic HER-2/neu-overexpressing breast cancer when combined with chemotherapy and has recently been demonstrated to lead to dramatic improvements in disease-free survival when used in the adjuvant therapy setting in combination with or following chemotherapy. However, potential cardiotoxicity requires careful patient selection. Here, we review the recently completed clinical trials of adjuvant trastuzumab in the adjuvant setting. HER-2/neu testing, patient selection, cardiotoxicity, duration of therapy, and directions for future research are discussed.

Molecular dissection of 17q12 amplicon in upper gastrointestinal adenocarcinomas

DNA amplification at 17q is frequently detected in upper gastrointestinal adenocarcinomas (UGC; stomach and esophagus). In this study, we did fluorescence in situ hybridization on a tissue microarray that contained 304 UGCs and 89 normal stomach samples using a approximately 168-kb BAC clone (CTD-2019C10) that maps to 17q12-q21.1. This 168-kb region contains the following genes: PPP1R1B/DARPP-32, STARD3, TCAP, PNMT, PERLD1, ERBB2, C17orf37, and GRB7 as well as the first two exons of ZNFN1A3. DNA amplification (> or =5 signals) was detected in 85 of 282 (30%) of UGCs, and high-level amplification (> or =10 signals) was seen in 28 of 282 (10%) of all tumors. Adenocarcinomas of gastroesophageal junction and lower esophagus had the highest frequency of amplification (45%) compared with stomach tumors (27%; P = 0.04). On the other hand, 38% of tumors with intestinal-type morphology had amplification compared with 26% of diffuse-type tumors (P = 0.02). We further did quantitative real-time reverse transcription-PCR on 74 frozen tissue samples from UGCs for 11 genes located within or adjacent to the boundaries of this approximately 168-kb genomic region. These genes include all 9 genes that are fully or partially located inside the CTD-2019C10 clone as well as 2 additional adjacent genes (NEUROD and TOP2A). Overexpression of PPP1R1B/DARPP-32, TCAP, and TOP2A was seen in approximately half of the tumors, whereas STARD3 and ZNFN1A3 were rarely overexpressed (12%). Interestingly, there was a statistical correlation between expression of all 8 genes that map between PPP1R1B/DARPP-32 and GRB7, whereas expression of NEUROD, ZNFN1A3, and TOP2A that are partially inside or adjacent to the boundaries of the CTD-2019C10 clone did not correlate with the expression of any of these 8 genes. These data show a transcriptionally active oncogenomic region bounded by PPP1R1B/DARPP-32 and GRB7 in UGCs and provide further insight into expression levels of several critical genes.