Clinical relevance of the putative stem cell marker p63 in breast cancer

P63 is a member of the p53 family. This protein is crucial for the maintenance of a stem cell population in the human epithelium and necessary for the normal development of all epithelial tissues including mammary glands. In normal breast tissue, the p63 seems to be a specific myoepithelial cell marker. P63 expression has been described in highly aggressive ER negative basal-like breast tumors. The value of p63 expression in ER positive disease is less clear. The expression levels of p63 mRNA by Affymetrix microarray analysis in a combined cohort of 2,158 ER positive breast cancers and its prognostic and predictive impact were analyzed. Tumor samples containing large amounts of benign breast tissue, which will interfere with p63 measurement, were excluded prior to the analysis. Survival analysis revealed a better prognosis of ER positive breast cancer expressing p63 (n = 410; P < 0.036). No correlation of p63 with standard parameters was observed. In a subgroup analysis, endocrine-treated patients with high p63 expression showed a better prognosis than low p63 expression (P = 0.06; n = 186). In untreated patients, this effect was less clear (n = 148; P = 0.5). P63 is a positive prognostic factor in endocrine-treated ER positive breast cancer and might influence responsiveness to endocrine treatment. Thus, p63 could be helpful as a predictive factor for endocrine therapy.

Determination of reaction parameters for the synthesis of the serotonin transporter ligand [11C]DASB: Application to a remotely controlled high yield synthesis

The synthesis of [11C]DASB is known to be performed by reacting the demethyl-DASB precursor with [11C]methyl iodide but the necessary reaction parameters had hitherto not been determined. In this work the dependence of the labelling yield on reaction temperature, reaction time, precursor concentration and type of solvent was investigated. Best results were found when methylation was carried out at 100 °C within 2 min using 4 mg/ml demethyl precursor in DMSO. With respect to [11C]methyl iodide a radiochemical yield of 74%±3% [11C]DASB was achieved. In addition, the synthesis was transferred to a remotely controlled module. A carbon-11 production for 1 h at 50 μA resulted in 3800-4300 MBq [11C]DASB with a specific activity of 152-211 GBq/μmol (4.1-5.7 Ci/μmol) (EOS) and a radiochemical purity of >95% in a sterile solution ready for injection. The total synthesis time was 45 min after EOB.

Evaluation of tumor-associated lymphocytes as a predictor of response to neoadjuvant chemotherapy in breast cancer: Results from the GeparDuo and GeparTrio trial

11054

Background: Preclinical investigations suggest an involvement of the immune system in chemotherapy response; however, this contribution has not been validated in prospective clinical trials so far. Methods: We investigated the inflammatory infiltrate in a total of 1058 pretherapeutic breast cancer core biopsies from two neoadjuvant anthracycline-taxane-based studies. As a training cohort, we used 218 core biopsies from the GeparDuo study. The results were validated in a completely independent cohort of 840 samples from the GeparTrio study. In addition, molecular parameters of lymphocyte recruitment and activation in breast cancer tissue were evaluated by kinetic PCR. Results: While the overall rate of pathological complete response (pCR) in the GeparDuo cohort was 12.8%, it was significantly increased to 42.7% in the tumors with more than 60% intratumoral or stromal lymphocytes. In a multivariate regression analysis, the percentage of intratumoral lymphocytes (iTu-Ly) was an independent significant parameter for pCR (P = 0.013) in the GeparDuo cohort. In the validation set from the GeparTrio trial, the inflammatory infiltrate was a strong predictor of pCR in univariate (P < 0.0005) and multivariate logistic regression (P < 0.0005). For tumors with 60% iTu-Ly the pCR rate was 40% with an odds ratio (OR) of 8.5 (4.0–18.2) which were similar to those values in hormone receptor negative samples (pCR: 36%; OR: 6.0 [4.0–9.1]). The expression of inflammatory marker genes and chemokines related to B and T infiltration in tumor tissue was significantly linked to the presence of a lymphocytic infiltrate and mRNA expression data showed a significant association of T cell markers with a pCR (P < 0.003). Conclusions: An increased lymphocytic inflammatory infiltrate in breast cancer is a new independent predictor of response to anthracyclin-taxane neoadjuvant chemotherapy and might be helpful to identify patients with benefit from cytotoxic chemotherapy.

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Use of microarray analysis of differentially expressed genes in luminal B subtype of breast cancers to evaluate NHERF1 as a marker of endocrine resistance

11015

Background: In vitro and in vivo data demonstrate that the expression of estrogen receptor (ER) in breast cancer is mainly associated with low proliferation. Gene expression profiling has recently been used to identify a group of high proliferating estrogen receptor positive breast cancers (the luminal B subtype), which are associated with a prognosis that is even worse than that of high proliferating estrogen receptor negative tumors. The analysis of those tumors might provide valuable information about breast cancer biology and could be helpful for adjuvant or neoadjuvant treatment decisions.Methods and Results: We analyzed microarray data from breast cancer specimens to gain insight into genes which play a role in estrogen receptor signalling. Genes were identified showing strong expression in high proliferating ER-positive tumors but no expression in either Ki67-/ER+ or Ki67+/ER- samples. Among these genes the Na+/H+ exchanger regulatory factor NHERF1 was found. We assessed the clinical relevance of NHERF1 transcript levels using a total of 2469 breast cancers. Analysis indicates that enhanced NHERF1 expression is associated with metastatic progression and poor prognosis of breast cancer patients. We found no correlation between NHERF1 and the nodal status as well as age, but positive correlations for tumor size (P<0.001), grade (P<0.001) and erbb2 (P=0.033). Weak NHERF1 expression correlated with longer disease free survival (DFS) in grade 1 and 2 tumors, but not in grade 3 breast cancers. Since NHERF1 expression is strongly linked to the presence of ER, the predictive value for endocrine treatment was analyzed. For samples with weak or none NHERF1 expression a treatment benefit was observed (P=0.007). While untreated patients display a 10 yr DFS rate of 67.2 ± 3.8%, endocrine treatment resulted in 80.1 ± 4.0%. In contrast no differences in disease free survival were found for corresponding NHERF1 expressing breast cancers. Conclusions: Our data indicate that expression of NHERF1 defines a state of differentiation, where breast cancer cells are refractory to endocrine treatment.

No significant financial relationships to disclose.

Prognostic value of gene expression of p63 by microarray analysis in estrogen receptor positive and negative breast cancer

566

Background: The protein 63 (p63) represents a member of the p53 family (p53/p63/p73) located on chromosome 3q27. This gene family seems to play an important role in carcinogenesis and its members may act as oncogenes or tumor suppressor genes. P63 is overexpressed in many different tumors like head and neck cancer, lung cancers, uterine tumors and breast cancer, and has been associated with poor prognosis in some studies. P63 was found to be overexpressed in a subset of highly aggressive breast cancers that represent a basal and myoepithelial phenotype and have a poor clinical outcome. This protein seems to be a specific myoepithelial cell marker in normal breast tissue and might represent a prognostic factor in breast cancer. Methods: Large scale analysis was performed using Affymetrix microarray data from n=1581 breast cancer patients to evaluate p63 expression. Results: P63 expression showed a strong correlation with patient's age (χ2-test, p < 0.001), tumor size (p < 0.003), proliferation rate (p < 0.001), Topo2α expression (p = 0.001) and estrogen receptor expression (p = 0.017). Survival analysis of all patients with available follow up data (n = 1263) showed a significant difference due to high and low p63 expression (log rank p < 0.001). Patients with a low p63 expression had the worst prognosis. In univariate Cox regression analysis p63 showed a hazard ratio (HR) of 1.61 (95% CI 1.31–2.00, p < 0.001) for disease free survival. This prognostic impact remained significant when samples were stratified by estrogen receptor status. High expression of p63 was significantly associated with longer OS in both ER negative (n = 334, log rank p = 0.022) and ER positive (n = 929, log rank p < 0,001) breast cancer. The prognostic impact of p63 expression was independent of Ki67 expression (p = 0.011 and p = 0.001 for high and low Ki67, respectively). Moreover a worse prognosis of low p63 expressing tumors was found in both subgroups of ErbB2 positive tumors (p < 0.001) and ErbB2 negative tumors (p < 0.001). Conclusions: P63 expression is a prognostic factor in both ER positive and negative breast cancer and could be helpful for risk assessment in breast cancer patients.

No significant financial relationships to disclose.

T cell marker metagene predicts a favourable prognosis in estrogen receptor negative and Her2 positive breast cancers

Abstract #1048

Background: Lymphocyte infiltration (LI) is often seen in breast cancer and has been suggested as a marker of host antitumor immune response but its importance remains controversial. A positive correlation of Her2 amplification/overexpression and LI has been described which was associated with a more favorable outcome. In rapidly proliferating tumors LI is a good prognostic indicator correlating with lymph node negativity, smaller tumor size, lower grade. However the impact of monocytes, B- and T-lymphocytes on prognosis are still a matter of debate.&#x2028; Material and Methods: A database of 2110 primary invasive breast cancer samples from 14 microarray datasets was established. Only Affymetrix HG-U133A microarrays were included for full comparability. Feature reduction was achieved by generating metagenes from genes with strong correlation in unsupervised clustering. The relationship of the five major metagenes with different cell types in the sample as well as differentiation programs/pathways associated with specific expression profiles was analyzed.&#x2028; Results: A large cluster of approximately 600 genes with functions in immune cells was consistently obtained in all datasets. The redundant information from several ProbeSets allowed the construction of robust metagenes which can be used as surrogate markers for the amount of different immune cell types in the breast cancer sample. However, rather complex relationships of these immunological metagenes with standard parameters of the tumors were observed. When different subgroups of tumors were analyzed for disease free survival the IgG metagene as a surrogate marker for B cells had no significant prognostic value. In contrast high expression of the T cell surrogate marker (LCK metagene) was beneficial among all subgroups of ER-negative tumors. Moreover a positive prognostic value of LCK metagene expression was also revealed for those ER-positive tumors with a Her2 overexpression. In addition a trend for a better response to neoadjuvant chemotherapy was detected for those ER negative tumors associated with lymphocyte infiltration as deduced from high expression of both IgG and LCK metagenes.&#x2028; Conclusions: Tumor associated lymphocytes could represent an anti tumor response but on the other hand they might promote tumor progression by shifting the cytokine milieu toward angiogenic factors, inflammatory cytokines and matrix metallo-proteinases. Thus it is crucial to precisely define the specific subtypes of immune cells which are associated with the tumor. Our results demonstrate that this task can be accomplished by a detailed analysis of the expression of metagenes. These surrogate markers define subgroups of tumors with different prognosis.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1048.

Anxiety is associated with reduced central serotonin transporter availability in unmedicated patients with unipolar major depression: a [11C]DASB PET study

Serotonergic dysfunction may contribute to negative mood states in affective disorders. Some in vivo imaging studies showed reduced availability of serotonin transporters (5-HTT) in the brainstem and thalamus of patients with major depression. We tested the hypothesis that 5-HTT availability is reduced in unmedicated unipolar patients with major depression compared to healthy control subjects matched for gender, age, genotype and smoking status. Availability of 5-HTT was measured in vivo with positron emission tomography and [(11)C]-3-amino-4-(2-dimethylaminomethyl-phenylsulfanyl)-benzonitrile (DASB) in the midbrain, thalamus and amygdala. DASB binding was correlated with the severity of depression (Beck's Depression Inventory), anxiety (Spielberger's State-Trait Anxiety Inventory) and personality traits (Temperament and Character Inventory). Patients with major depression displayed reduced 5-HTT availability in the thalamus (P=0.005). In patients, low serotonin transporter availability correlated with high anxiety (thalamus: r=-0.78, P=0.004; midbrain: r=-0.78, P=0.004; amygdala: r=-0.80, P=0.003). Correlations with severity of depression were weaker and did not survive correction for multiple testing. These results support the hypothesis that central serotonergic dysfunction is associated with negative mood states in affective disorders. In the thalamus, a low serotonin reuptake capacity may interfere with thalamic control of cortical excitability and contribute to anxiety rather than depression per se in major depression.

Production of [11C]chloroform by direct chlorination of [11C]methane without catalyst support for the synthesis of [11C]diazomethane

The preparation of [11C]chloroform by direct chlorination of [11C]methane using gaseous chlorine by variation of temperature and reaction time (inert gas flow) without catalyst support for the online production of [11C]diazomethane in a flow-through synthesis apparatus is described in this work. At an oven temperature of 400 degrees C and a He flow of 50 mL/min, [11C]chloroform was synthesized inside a quartz glass column in a radiochemical yield of 31+/-2% with respect to [11C]methane. The online preparation of [11C]diazomethane by reaction of [11C]chloroform with hydrazine in an ethanolic KOH solution with small amounts of 18-crown-6-crownether succeeded with a radiochemical yield of 20+/-3% with respect to [11C]methane. The product [11C]diazomethane was measured indirectly in the form of 4-nitrobenzoic acid[11C]methylester using the esterification of 4-nitrobenzoic acid as a monitor reaction.

Reduced availability of serotonin transporters in obsessive-compulsive disorder correlates with symptom severity - a [11C]DASB PET study

Reduced availability of brainstem serotonin transporters (5-HTT) has been observed in vivo in obsessive-compulsive disorder (OCD). However, results vary and may be influenced by competition with endogenous serotonin. Using positron emission tomography (PET) and [11C]DASB, a specific 5-HTT ligand that showed no competition with serotonin for 5-HTT binding in vitro, we tested the hypothesis that 5-HTT availability is reduced in OCD patients and correlated with OCD severity. METHODS. 5-HTT availability in the thalamus and the midbrain was measured in nine drug-free OCD patients and compared with 19 healthy controls, matched for the individual combination of 5-HTT genotype, gender and smoking status. OCD severity was assessed with the Yale-Brown obsessive compulsive scale (Y-BOCS). RESULTS. 5-HTT availability was significantly reduced in the thalamus and midbrain of OCD patients. Age and 5-HTT in the thalamus explained 83% of OCD severity in patients that were drug-free for at least 1 year. CONCLUSION. This PET study confirms a central role of the serotonergic system, particularly the thalamus in the pathogenesis of obsessive compulsive disorder.

Breast cancers with stem cell-like features delineate endocrine responsiveness

10517

Background: Endocrine responsiveness is one of the most important characteristics of breast cancer. The negative association between expression of the estrogen receptor (ER) and proliferation detected in normal breast is frequently lost in breast cancers leading to receptor independent growth and poor patients’ prognosis. Methods: Microarray analysis of 171 breast cancer samples allowed the discrimination of a KIT+ tumor group by using a set of genes coregulated with the “stem cell factor” receptor KIT. Validation was performed on three independent datasets encompassing 637 samples. Furthermore the response to endocrine treatment only was analyzed in a dataset of 700 patients. Results: KIT+ tumors are transcriptionally related to proposed mammary stem cells. Two types of KIT+ tumors were identified which are characterized by their positive and negative ER status, respectively. The inverse link of ER expression and proliferation is perfectly conserved within the KIT+ tumor groups, while it is uncoupled among half of the KIT-Low ER positive tumors. Those “uncoupled” ER positive tumors with altered ER response are characterized by a prognosis inferior to the ER negative cancers despite an apparent positive ER status (hazard ratio for disease recurrence, 2.07; 95% CI 1.53–2.81; P<0.001). Moreover, the 5 and 10 year survival rates of lymph node negative “uncoupled” tumors are even worse than those of lymph node positive “normal” ER positive cancers. While all ER positive patients seem to profit from endocrine treatment the relative benefit was reduced in uncoupled tumors (21.2 % vs. 31.7 %). Conclusions: The classification of breast cancers according to this biologically based model identified clinical relevant tumor groups whose further characterization will have important implications. Moreover, since the ability to recognize malfunctions in ER pathways largely depends on an appropriate reference system, the KIT+ tumors could allow a dissection of estrogen responsiveness giving crucial insights for prediction of response to endocrine therapy.

No significant financial relationships to disclose.

Occupancy of dopamine D(1), D (2) and serotonin (2A) receptors in schizophrenic patients treated with flupentixol in comparison with risperidone and haloperidol

RATIONALE

Flupentixol (FLX) has been used as a neuroleptic for nearly 4 decades. In vitro data show comparable affinity to dopamine D(2), D(1) and 5-HT(2A) receptors and recently, FLX showed to be not inferior to risperidone in schizophrenic patients with predominant negative symptomatology, which was implicated with flupentixol's interaction with 5-HT(2A) and/or D(1) receptors.

OBJECTIVES

To assess in vivo receptor occupancy (RO) in patients clinically treated with FLX (n = 13, 5.7 +/- 1.4 mg/day) in comparison with risperidone (RIS, n = 11, 3.6 +/- 1.3 mg/day) and haloperidol (HAL, n = 11, 8.5 +/- 5.5 mg/day).

MATERIALS AND METHODS

Each patient underwent two PET scans with 3-N-[(11)C]methylspiperone (target: frontal 5-HT(2A)), [(11)C]SCH23390 (striatal D(1)) or [(11)C]raclopride (striatal D(2)). RO was calculated as the percentage reduction of specific binding in comparison with healthy controls.

RESULTS

D(2)-RO under FLX was between 50% and 70%, indicating an ED(50) of about 0.7 ng/ml serum. 5-HT(2A) and D(1)-RO was 20 +/- 10% and 20 +/- 5% (mean, SEM). Under HAL, D(1)-RO was 14 +/- 6% and under RIS not significantly different from zero.

CONCLUSIONS

We were able to demonstrate a moderate 5-HT(2A) and D(1) occupancy under clinically relevant doses of flupentixol, albeit lower than expected from in vitro data and clearly below saturation. Therefore, if flupentixol's efficacy on negative symptoms is based on its interaction with 5-HT(2A) and/or D(1) receptors, it should be highly dependent on serum concentration and thus on dosage and metabolism. However, these data suggest that mechanisms other than D(1) or 5-HT(2A) antagonism may contribute to flupentixol's efficacy on negative symptoms.

Midbrain serotonin transporter binding potential measured with [11C]DASB is affected by serotonin transporter genotype

BACKGROUND

Homozygote carriers of two long (L) alleles of the serotonin transporter (5-HTT) regulatory region displayed in vitro a twofold increase in 5-HTT expression compared with carriers of one or two short (S) alleles. However, in vivo imaging studies yielded contradictory results. Recently, an A > G exchange leading to differential transcriptional activation of 5-HTT mRNA in lymphobalstoid cell lines was discovered in the 5-HTT regulatory region. In vitro and in vivo evidence suggests that [(11)C]DASB, a new 5-HTT ligand offers some advantages over the ligands used in previous studies in measuring 5-HTT density independent of synaptic levels of serotonin.

METHOD

We assessed 5-HTT binding potential (BP (2)) in the midbrain of 19 healthy subjects with positron emission tomography and [(11)C]DASB. Accounting for the hypothesized functional similarity of L (G) and S in driving 5-HTT transcription, we assessed whether L (A) L (A) homozygotes display increased midbrain BP (2) compared with carriers of at least one S allele.

RESULTS

BP (2) in the midbrain was significantly increased in L (A) L (A) homozygotes compared with carriers of at least one S allele. Interestingly, the genotype effect on the midbrain was significantly different from that on the thalamus and the amygdala where no group differences were detected.

CONCLUSIONS

This in vivo study provides further evidence that subjects homozygous for the L (A) allele display increased expression of 5-HTT in the midbrain, the origin of central serotonergic projections.

Gene expression profiling of breast cancer patients treated with docetaxel, doxorubicin, and cyclophosphamide within the GEPARTRIO trial: HER-2, but not topoisomerase II alpha and microtubule-associated protein tau, is highly predictive of tumor response

Gene expression analysis in breast cancer patients undergoing neoadjuvant chemotherapy is an interesting tool for identification of gene signatures and new markers to predict tumor response. However, the detection of predictive markers strongly depends on the drugs used in the specific therapeutic setting. There is growing evidence that topoisomerase II-alpha (TOPO IIalpha) is a marker for anthracycline-, and microtubule-associated protein tau (MAPT) for taxane sensitivity. HER-2 has been described as a marker of both anthracycline and taxane sensitivity. We performed gene expression profiling of 50 patients within the GEPARTRIO study, an anthracycline and taxane neoadjuvant chemotherapy trial. Here we investigate the predictive value of TOPO IIalpha, MAPT and HER-2 mRNA expression for pathological complete response (pCR) in this setting. Interestingly, HER-2 gene expression was strongly predictive of pCR (P=0.017) as well as overall response (P=0.037) and clinical complete response (cCR, P=0.050). In contrast, for both TOPO IIalpha and MAPT no correlation with pCR was observed in our sample group.