Prognostic utility of β-tubulin isotype III and correlations with other molecular and clinicopathological variables in patients with early breast cancer: a translational Hellenic Cooperative Oncology Group (HeCOG) study

The Genomic Landscape of Breast Cancer in Young and Older Women

BACKGROUND

Young women with breast cancer (YWBC; ≤40 years) often have a poorer prognosis than older women with breast cancer (OWBC; ≥65 years). We explored molecular features of tumors from YWBC and OWBC to identify a biologic connection for these patterns.

MATERIALS AND METHODS

We retrospectively analyzed the molecular profiles of 1879 breast tumors. Testing included immunohistochemistry (IHC), in situ hybridization (ISH), and next-generation sequencing. Statistical analyses included Pearson's chi2 test for comparisons, with significance defined as FDR (false discovery rate)-P < .05.

RESULTS

TP53 and BRCA1 somatic mutations were more common in YWBC tumors than in OWBC tumors (53%, 42%; P = .0001, FDR-P = .0025 and 7%, 2%; P = .0001, FDR-P = .0025; respectively). Conversely, OWBC tumors had higher androgen receptor expression (55%, 45%; P = .0002, FDR-P = .0025) higher PD-L1 expression detected by IHC (8%, 5%; P = .0476, FDR-P = .2754), and more frequent PIK3CA mutations (33%, 17%; P = < .0001, FDR-P = < .0001). Among HR+/HER2- samples, YWBC had more gene amplifications in FGF3 (27%, 10%; P = .0353, FDR-P = .2462), FGF4 (27%, 9%; P = .0218, FDR-P = .1668), FGF19 (30%, 12%; P = .034, FDR-P = .2462) and CCND1 (37%, 18%; P = .0344, FDR-P = .2462) than OWBC.

CONCLUSIONS

Our data suggest distinct molecular aberrations exist between YWBC and OWBC. Exploiting these molecular changes could refine our treatment strategies in YWBC and OWBC.

The Role of Galectin3, Tubulinβ, and Maspin in Promoting Tumor Budding in Colorectal Carcinoma and Their Clinical Implications

Colorectal cancer (CRC) is a leading cause of death worldwide. Despite the advances in surgical and therapeutic management, tumor metastases and poor prognosis are still major problems. Tumor budding is a relevant prognostic factor in CRC, and it can predict tumor metastasis. Galectin3 is responsible for the development and progression of many cancers through the regulation of cell-cell/cell-matrix interactions and tumor cell invasion. Tubulin is a microtubule protein, and maspin is a serine protease inhibitor; both induce tumor cell invasion through the stimulation of epithelial-mesenchymal transition. This study aims to evaluate the relationship between the expression of galecin3, tubulinβ, and maspin in CRC and clinicopathological features, including tumor budding, their prognostic roles, and clinical implications using immunohistochemistry. Galectin3, tubulinβ, and maspin were detected in tumor cells in 95%, 65%, and 87.5% of cases and in stromal cells in 28.8%, 40%, and 0% of cases. High expression of galectin3 and tubulinβ expression either in tumor cells or stroma was significantly associated with aggressive tumor features such as lymph node metastasis, lymphovascular invasion, tumor budding, and advanced tumor stage. The nucleocytoplasmic expression of maspin in tumor cells showed a significant association with deeper tumor invasion, lymph node metastasis, tumor budding, and advanced tumor stage. Significant associations were found between high galectin3 tumor cell expression and nucleocytoplasmic maspin and shorter survival. High expression of galectin3, tubulinβ, and nucleocytoplasmic maspin were significantly associated with aggressive tumor features such as tumor invasion, metastasis, high tumor budding, and short survival in CRC. They could be used as biomarkers for tumor budding and tumor aggressiveness in CRC and may be considered for future target therapy.

Targeting hormone-resistant breast cancer cells with docetaxel: a look inside the resistance

Aim: The study aims to analyze the effect of long-term incubation of ERα-positive MCF7 breast cancer cells with 4-hydroxytamoxifen (HT) on their sensitivity to tubulin polymerization inhibitor docetaxel. Methods: The analysis of cell viability was performed by the MTT method. The expression of signaling proteins was analyzed by immunoblotting and flow cytometry. ERα activity was evaluated by gene reporter assay. To establish hormone-resistant subline MCF7, breast cancer cells were treated with 4-hydroxytamoxifen for 12 months. Results: The developed MCF7/HT subline has lost sensitivity to 4-hydroxytamoxifen, and the resistance index was 2. Increased Akt activity (2.2-fold) and decreased ERα expression (1.5-fold) were revealed in MCF7/HT cells. The activity of the estrogen receptor α was reduced (1.5-fold) in MCF7/HT. Evaluation of class III β-tubulin expression (TUBB3), a marker associated with metastasis, revealed the following trends: higher expression of TUBB3 was detected in triple-negative breast cancer MDA-MB-231 cells compared to hormone-responsive MCF7 cells (P < 0.05). The lowest expression of TUBB3 was found in hormone-resistant MCF7/HT cells (MCF7/HT < MCF7 < MDA-MB-231, approximately 1:2:4). High TUBB3 expression strongly correlated with docetaxel resistance: IC₅₀ value of docetaxel for MDA-MB-231 cells was greater than that for MCF7 cells, whereas resistant MCF7/HT cells were the most sensitive to the drug. The accumulation of cleaved PARP (a 1.6-fold increase) and Bcl-2 downregulation (1.8-fold) were more pronounced in docetaxel-treated resistant cells (P < 0.05). The expression of cyclin D1 decreased (2.8-fold) only in resistant cells after 4 nM docetaxel treatment, while this marker was unchanged in parental MCF7 breast cancer cells. Conclusion: Further development of taxane-based chemotherapy for hormone-resistant cancer looks highly promising, especially for cancers with low TUBB3 expression.

Comparative evaluation of somatostatin and CXCR4 receptor expression in different types of thyroid carcinoma using well-characterised monoclonal antibodies

Background

Papillary and follicular thyroid carcinomas can be treated surgically and with radioiodine therapy, whereas therapeutic options for advanced stage IV medullary and for anaplastic tumours are limited. Recently, somatostatin receptors (SSTs) and the chemokine receptor CXCR4 have been evaluated for the treatment of thyroid carcinomas, however, with contradictory results.

Methods

The expression of the five SSTs and of CXCR4 was assessed in 90 samples from 56 patients with follicular, papillary, medullary, or anaplastic thyroid carcinoma by means of immunohistochemistry using well-characterised monoclonal antibodies. The stainings were evaluated using the Immunoreactivity Score (IRS) and correlated to clinical data. In order to further substantiate the immunohistochemistry results, in serial sections of a subset of the samples receptor expression was additionally examined at the mRNA level using qRT-PCR.

Results

Overall, SST and CXCR4 protein expression was low in all four entities. In single cases, however, very high IRS values for SST2 and CXCR4 were observed. SST2 was the most frequently expressed receptor, found in 38% of cases, followed by SST5 and SST4, found in 14 and 9% of tumours, respectively. SST1 and SST3 could not be detected to any significant extent. CXCR4 was present in 12.5% of medullary and 25% of anaplastic carcinomas. Expression SST3, SST4, SST5 and CXCR4 was positively correlated with expression of the proliferation marker Ki-67. Additionally, a negative interrelationship between SST4 or SST5 expression and patient survival and a positive association between SST3 expression and tumour diameter were observed. qRT-PCR revealed a similar receptor expression pattern to that seen at the protein level. However, probably due to the low overall expression, no correlation was found for the SSTs or the CXCR4 between the IRS and the mRNA values.

Conclusions

SST- or CXCR4-based diagnostics or therapy in thyroid carcinomas should not be considered in general but may be feasible in single cases with high levels of expression of these receptors.

Assessment of G Protein-Coupled Oestrogen Receptor Expression in Normal and Neoplastic Human Tissues Using a Novel Rabbit Monoclonal Antibody

In addition to the classical oestrogen receptors, ERα and ERβ, a G protein-coupled oestrogen receptor (GPER) has been identified that primarily mediates the rapid, non-genomic signalling of oestrogens. Data on GPER expression at the protein level are contradictory; therefore, the present study was conducted to re-evaluate GPER expression by immunohistochemistry to obtain broad GPER expression profiles in human non-neoplastic and neoplastic tissues, especially those not investigated in this respect so far. We developed and thoroughly characterised a novel rabbit monoclonal anti-human GPER antibody, 20H15L21, using Western blot analyses and immunocytochemistry. The antibody was then applied to a large series of formalin-fixed, paraffin-embedded human tissue samples. In normal tissue, GPER was identified in distinct cell populations of the cortex and the anterior pituitary; islets and pancreatic ducts; fundic glands of the stomach; the epithelium of the duodenum and gallbladder; hepatocytes; proximal tubules of the kidney; the adrenal medulla; and syncytiotrophoblasts and decidua cells of the placenta. GPER was also expressed in hepatocellular, pancreatic, renal, and endometrial cancers, pancreatic neuroendocrine tumours, and pheochromocytomas. The novel antibody 20H15L21 will serve as a valuable tool for basic research and the identification of GPER-expressing tumours during histopathological examinations.

BET inhibition increases βIII-tubulin expression and sensitizes metastatic breast cancer in the brain to vinorelbine

Metastases from primary breast cancer result in poor survival. βIII-tubulin (TUBB3) has been established as a therapeutic target for breast cancer metastases specifically to the brain. In this study, we conducted a systematic analysis to determine the regulation of TUBB3 expression in breast cancer metastases to the brain and strategically target these metastases using vinorelbine (VRB), a drug approved by the U.S. Food and Drug Administration (FDA). We found that human epidermal growth factor receptor 2 (HER2) signaling regulates TUBB3 expression in both trastuzumab-sensitive and trastuzumab-resistant neoplastic cells. We further discovered that bromodomain and extra-terminal domain (BET) inhibition increases TUBB3 expression, rendering neoplastic cells more susceptible to apoptosis by VRB. Orthotopic xenograft assays using two different breast cancer cell models revealed a reduction in tumor volume with BET inhibition and VRB treatment. In addition, in vivo studies using a model of multiple brain metastasis (BM) showed improved survival with the combination of radiation + BET inhibitor (iBET-762) + VRB (75% long-term survivors, P < 0.05). Using in silico analysis and BET inhibition, we found that the transcription factor myeloid zinc finger-1 (MZF-1) protein binds to the TUBB3 promoter. BET inhibition decreases MZF-1 expression and subsequently increases TUBB3 expression. Overexpression of MZF-1 decreases TUBB3 expression and reduces BM in vivo, whereas its knockdown increases TUBB3 expression in breast cancer cells. In summary, this study demonstrates a regulatory mechanism of TUBB3 and provides support for an application of BET inhibition to sensitize breast cancer metastases to VRB-mediated therapy.

Extensive analysis of the molecular biomarkers excision repair cross complementing 1, ribonucleotide reductase M1, β-tubulin III, thymidylate synthetase, and topoisomerase IIα in breast cancer: Association with clinicopathological characteristics

Excision repair cross complementing 1 (ERCC1), ribonucleotide reductase M1 (RRM1), β-tubulin III (TUBB3), thymidylate synthetase (TYMS), and topoisomerase IIα (TOP2A) genes have been shown to be associated with the pathogenesis and prognosis of various types of carcinomas; however, their roles in breast cancer have not been fully validated. In this study, we evaluated the correlations among these biomarkers and the associations between their expression intensity and the clinicopathological characteristics to investigate whether the above genes are underlying biomarkers for patients with breast cancer.Ninety-seven tissue specimens collected from breast cancer patients. The expression levels of these biomarkers were measured by the multiplex branched DNA liquidchip (MBL) technology and clinicopathological characteristics were collected simultaneously.The expression levels of ERCC1, TUBB3, TYMS, and TOP2A were significantly associated with the characteristics of menopausal status, tumor size, lymph node metastasis, hormone receptor status, triple-negative status, Ki-67 index, and epidermal growth factor receptor. The expression intensity of ERCC1 negatively associated with that of TUBB3 and TYMS, and positively associated with that of RRM1. The expression intensity of TOP2A positively associated with that of TYMS. Hierarchical clustering analysis and difference test indicated that breast cancer with higher levels of TUBB3, TYMS, and TOP2A, as well as lower levels of ERCC1 and RRM1 tended to have higher histological grade and Ki-67 index.Our studies showed that ERCC1, TYMS, TUBB3, and TOP2A may be potential biomarkers for prognosis and individualized chemotherapy guidance, while there may be interactions between ERCC1 and RRM1, or TUBB3, or TYMS, as well as between TOP2A and TYMS in pathogenesis and development of breast cancer.

Radiation-Related Deregulation of TUBB3 and BRCA1/2 and Risk of Secondary Lung Cancer in Women With Breast Cancer

INTRODUCTION

Breast cancer survivors are at increased risk of developing unrelated primary cancers, particularly lung cancer. Evidence indicates that sex hormones as well as a deregulation of DNA-repair pathways may contribute to lung cancer onset. We investigated whether the hormone status and expression of markers involved in DNA repair (BRCA1/2, ERCC1, and P53R2), synthesis (TS and RRM1), and cell division (TUBB3) might be linked to lung cancer risk.

PATIENTS AND METHODS

Thirty-seven breast cancer survivors with unrelated lung cancer and 84 control subjects comprising women with breast cancer (42/84) or lung cancer (42/84) were enrolled. Immunohistochemistry on tumor tissue was performed. Geometric mean ratio was used to assess the association of marker levels with patient groups.

RESULTS

Estrogen receptor was expressed in approximately 90% of the breast cancer group but was negative in the majority of the lung cancer group, a result similar to the lung cancer control group. Likewise, ER isoform β was weakly expressed in the lung cancer group. Protein analysis of breast cancer versus control had a significantly lower expression of BRCA1, P53R2, and TUBB3. Likewise, a BRCA1 reduction was observed in the lung cancer group concomitant with a BRCA2 increase. Furthermore, BRCA2 and TUBB3 increased in ipsilateral lung cancer in women who had previously received radiotherapy for breast cancer.

CONCLUSION

The decrease of DNA-repair proteins in breast cancer could make these women more susceptible to therapy-related cancer. The increase of BRCA2 and TUBB3 in lung cancer from patients who previously received radiotherapy for breast cancer might reflect a tissue response to exposure to ionizing radiation.

Progress of Individualized Chemotherapy for Gastric Carcinoma Under the Guidance of Genetic Testing

BACKGROUND

Gastric cancer is a major malignancy that has high incidence rates worldwide. Approximately 30% of patients with gastric cancer have progressed into advanced stages at the time of diagnosis. Chemotherapy is the standard-of-care for most advanced gastric cancer and elicits variable responses among patients. Personalized chemotherapy based on genetic information of individual patients with gastric cancer has gained increasing attention among oncologists for guiding chemotherapeutic regimens.

METHODS

This review summarizes recent progress of individualized chemotherapy in gastric cancer guided by pharmacogenomics. Variable medical research search engines, such as PubMed, Google Scholar, SpringerLink and ScienceDirect, were used to retrieve related literature. Only peerreviewed journal articles were selected for further analyses.

RESULTS AND CONCLUSION

The efficiency of chemotherapy in patients with gastric cancer is not only determined by chemotherapeutic drugs but is also directly and indirectly influenced by functionally correlative genes. Individual gene alteration or polymorphism remarkably affects patients' responses to particular chemotherapy. Most studies have focused on the influence of single-gene alteration on a selected drug, and only a few works explored the interaction between therapeutics and a panel of genes. Individualized chemotherapy regimens guided by a genetic survey of a multiple-gene panel are expected to remarkably improve the treatment efficacy in patients with advanced gastric cancer and may become the new standard for personalizing chemotherapy for gastric cancer in the near future.

Quantification and expert evaluation of evidence for chemopredictive biomarkers to personalize cancer treatment

Predictive biomarkers have the potential to facilitate cancer precision medicine by guiding the optimal choice of therapies for patients. However, clinicians are faced with an enormous volume of often-contradictory evidence regarding the therapeutic context of chemopredictive biomarkers.

We extensively surveyed public literature to systematically review the predictive effect of 7 biomarkers claimed to predict response to various chemotherapy drugs: ERCC1-platinums, RRM1-gemcitabine, TYMS-5-fluorouracil/Capecitabine, TUBB3-taxanes, MGMT-temozolomide, TOP1-irinotecan/topotecan, and TOP2A-anthracyclines. We focused on studies that investigated changes in gene or protein expression as predictors of drug sensitivity or resistance. We considered an evidence framework that ranked studies from high level I evidence for randomized controlled trials to low level IV evidence for pre-clinical studies and patient case studies.

We found that further in-depth analysis will be required to explore methodological issues, inconsistencies between studies, and tumor specific effects present even within high evidence level studies. Some of these nuances will lend themselves to automation, others will require manual curation. However, the comprehensive cataloging and analysis of dispersed public data utilizing an evidence framework provides a high level perspective on clinical actionability of these protein biomarkers. This framework and perspective will ultimately facilitate clinical trial design as well as therapeutic decision-making for individual patients.

Evaluation of somatostatin, CXCR4 chemokine and endothelin A receptor expression in a large set of paragangliomas

Paragangliomas are predominantly benign tumors, but in some cases invasive growth and also metastasis are observed. Given the limited number of nonsurgical treatment options, novel target structures for diagnostics and therapy of this tumor entity are urgently needed. In the present study, expression of all five somatostatin receptor (SST) subtypes, chemokine receptor CXCR4 and endothelin receptor type A (ETA) was assessed by means of immunohistochemistry in a total of 66 paraffin-embedded paraganglioma samples from 55 patients. The stainings were rated by means of the Immunoreactive Score and correlated to clinical data and to succinate dehydrogenase subunit B (SDHB) expression. SST2A was by far the most prominent receptor in the paragangliomas investigated. It was present in 89% of the tumors at a high intensity, followed by SST5, SST3, SST1 and SST4, which were detected in 47%, 35%, 35% and 13% of the samples, respectively. SDHB positive tumors exhibited significantly higher SST2A and SST3 expression as compared to SDHB negative cases. There was no correlation between SST and Ki-67 expression or grading of the tumors and no difference in SST expression between primary tumors and metastases. Cell surface expression of CXCR4 and ETA was detected only in few samples. On tumor capillaries, however, exceptionally strong staining for these two receptors was noticed in the vast majority of the tumors. In conclusion, paragangliomas are well suited for SST2A-based diagnostics and treatment modalities. An indirect targeting of these highly vascularized tumors via CXCR4 or ETA may also represent a promising future strategy.

Expression of somatostatin receptors 2 and 5 in circulating tumour cells from patients with neuroendocrine tumours

BACKGROUND

Neuroendocrine tumours (NET) overexpress somatostatin receptors (SSTR) that can be targeted for therapy. Somatostatin receptor expression is routinely measured by molecular imaging but the resolution is insufficient to define heterogeneity. We hypothesised that SSTR expression could be measured on circulating tumour cells (CTCs) and used to investigate heterogeneity of expression and track changes during therapy.

METHODS

MCF-7 cells were transfected with SSTR2 or 5 and spiked into donor blood for analysis by CellSearch. Optimum anti-SSTR antibody concentration and exposure time were determined, and flow cytometry was used to evaluate assay sensitivity. For clinical evaluation, blood was analysed by CellSearch, and SSTR2/5 immunohistochemistry was performed on matched tissue samples.

RESULTS

Flow cytometry confirmed CellSearch was sensitive and that detection of SSTR was unaffected by the presence of somatostatin analogue up to a concentration of 100 ng ml-l. Thirty-one NET patients were recruited: grade; G1 (29%), G2 (45%), G3 (13%), primary site; midgut (58%), pancreatic (39%). Overall, 87% had SSTR-positive tumours according to somatostatin receptor scintigraphy or 68-Ga-DOTATE PET/CT. Circulating tumour cells were detected in 21 out of 31 patients (68%), of which 33% had evidence of heterogeneous expression of either SSTR2 (n=5) or SSTR5 (n=2).

CONCLUSIONS

Somatostatin receptors 2 and 5 are detectable on CTCs from NET patients and may be a useful biomarker for evaluating SSTR-targeted therapies and this is being prospectively evaluated in the Phase IV CALMNET trial (NCT02075606).

Neural Transdifferentiation: MAPTau Gene Expression in Breast Cancer Cells

BACKGROUND

In tumor cells, aberrant differentiation programs have been described. Several neuronal proteins have been found associated with morphological neuronal-glial changes in breast cancer (BCa). These neuronal proteins have been related to mechanisms that are involved in carcinogenesis; however, this regulation is not well understood. Microtubule-associated protein-tau (MAP-Tau) has been describing in BCa but not its variants. This finding could partly explain the neuronal-glial morphology of BCa cells. Our aim was to determine mRNA expression of MAP-tau variants 2, 4 and 6 in breast cancer cell lines.

MATERIALS AND METHODS

Cultured cell lines MCF-10A, MDA-MB-231, SKBR3 and T47D were observed under phase-contrast microscopy for neural morphology and analyzed for gene expression of MAP-Tau transcript variants 2, 4 and 6 by real-time PCR.

RESULTS

Regarding morphology like neural/glial cells, T47D line shown more cells with these features than MDA-MB-231 and SKBR. In another hand, we found much greater mRNA expression of MAP-Tau transcript variants 2, and to a lesser extent 4 and 6, in T47D cells than the other lines. In conclusion, regulation of MAP- Tau could bring about changes in cytoskeleton, cell morphology and motility; these findings cast further light on neuronal transdifferentiation in BCa.

Differential expression and prognostic value of the chemokine receptor CXCR4 in bronchopulmonary neuroendocrine neoplasms

Introduction

For many tumors, the overexpression of the chemokine receptor CXCR4 is associated with increased malignancy and poor patient outcomes. However, comprehensive data for neuroendocrine neoplasms of the lung are still lacking.

Methods

CXCR4 expression was evaluated in a panel of bronchopulmonary neuroendocrine neoplasms (BP-NEN) comprising typical carcinoids (n = 26), atypical carcinoids (n = 30), and small cell lung cancers (SCLC, n = 34). Samples were analyzed by immunohistochemistry using the novel monoclonal rabbit anti-human CXCR4 antibody UMB-2 and by qRT-PCR. The expression was correlated with clinical data and overall patient survival.

Results

CXCR4 was predominantly localized at the plasma membrane of the tumor cells. CXCR4 was expressed with a high intensity in almost all of the 30 SCLC samples. In contrast, it was detected infrequently and with low intensity in the typical carcinoid and atypical carcinoid samples. There was a significant correlation between the immunohistochemistry and qRT-PCR data. Additionally, there was a significant negative relationship between CXCR4 expression and overall survival.

Conclusions

With increasing malignancy, BP-NEN clearly differ in the extent of CXCR4 expression. As in other tumor entities, CXCR4 overexpression significantly correlates with negative patient outcome. Due to its particular high expression rate in SCLC, CXCR4 may serve as a promising new target for diagnostic and pharmacological intervention as well as for peptide receptor-based radionuclide therapy.

High levels of class III β-tubulin expression are associated with aggressive tumor features in breast cancer

Overexpression of class III β-tubulin (TUBB3), a factor that confers dynamic properties to microtubules, is a candidate biomarker for resistance to microtubule-targeting chemotherapeutics in breast and other types of solid cancer. Discrepant results from previous studies, with respect to the association of TUBB3 expression levels with breast cancer phenotype and patient prognosis, prompted the present study to investigate TUBB3 expression in a large cohort of breast cancer cases, with available clinical follow-up data. A preexisting breast cancer prognosis tissue microarray, containing a single 0.6 mm tissue core from each of 2,197 individual patients with breast cancer, was analyzed for TUBB3 expression by immunohistochemistry. The results of the present study revealed that TUBB3 expression was less frequent in lobular breast cancer cases (34%), compared with that of cancer cases of alternative histologies, including breast cancer of no special type (60%; P<0.0001). High TUBB3 positivity was associated with high tumor grade (P<0.0001), negativity for estrogen (P<0.0001) and progesterone receptors (P<0.004), as well as the presence of human epidermal growth factor 2 amplification (P<0.0001) and a triple-negative phenotype (P<0.0001). TUBB3 overexpression was additionally associated with reduced patient survival if all breast cancer cases of any histology were jointly analyzed (P=0.0088); however this link was not evident in the subset of breast cancer cases of no special type, or in a multivariate analysis including the established prognostic factors of tumor stage, grade and nodal stage. In conclusion, the present study demonstrated that TUBB3 overexpression was associated with adverse features of breast cancer, and that TUBB3 may possess a distinct role in lobular breast cancer cases, compared with alternative histological subtypes. The results of the present study do not support a clinically relevant role for TUBB3 as a prognostic marker in breast cancer.

Expression of TS, RRM1, ERCC1, TUBB3 and STMN1 Genes in Tissues of Non-small Cell Lung Cancer and its Significance in Guiding Postoperative Adjuvant Chemotherapy

BACKGROUND

To explore the expression of TS, RRM, ERCC1, TUBB3 and STMN1 genes in the tissues of patients with non-small cell lung cancer (NSCLC) and its significance in guiding the postoperative adjuvant chemotherapy.

MATERIALS AND METHODS

Real time polymerase chain reaction (PCR) was applied to detect the expression of TS, RRM, ERCC1, TUBB3 and STMN1 genes in the tissues of NSCLC patients so as to analyze the relationship between the expression of each gene and the clinical characteristics and to guide the postoperative individualized chemotherapy according to the detection results of NSCLC patients.

RESULTS

Expression of TS gene was evidently higher in patients with adenocarcinoma than those with non-adenocarcinoma (P=0.013) and so was the expression of ERCC1 (P=0.003). The expression of TUBB3 gene was obviously higher in NSCLC patients in phases I/II and IV than those in phase III (P1=0.021; P2=0.004), and it was also markedly higher in patients without lymph node metastasis than those with (P=0.008). The expression of STMN1 gene was apparently higher in patients in phase I/II than those in phase IV (P=0.002). There was no significant difference between the rest gene expression and the clinical characteristics of NSCLC patients (P>0.05). Additionally, the disease- free survival (DFS) was significantly longer in patients receiving gene detections than those without (P=0.021).

CONCLUSIONS

The selection of chemotherapeutic protocols based singly on patients' clinical characteristics has certain blindness. However, the detection of tumor-susceptible genes can guide the postoperative adjuvant chemotherapy and prolong the DFS of NSCLC patients.

Interleukin-6 is a potential therapeutic target in interleukin-6 dependent, estrogen receptor-α-positive breast cancer

Introduction

Interleukin-6 (IL-6) is an important growth factor for estrogen receptor-α (ERα)-positive breast cancer, and elevated serum IL-6 is associated with poor prognosis.

Methods

The role of the phosphorylated signal transducer and activator of transcription 3 pathway was investigated in ERα-positive breast cancer. A panel of cell lines was treated with exogenous IL-6. An IL-6 specific gene signature was generated by profiling ten ERα-positive breast cancer cell lines alone or following treatment with 10 ng/mL recombinant IL-6 or human marrow stromal cell-conditioned media, with or without siltuximab (a neutralizing anti-IL-6 antibody) and grown in three-dimensional tumor microenvironment-aligned cultures for 4 days, 5 days, or 6 days. The established IL-6 signature was validated against 36 human ERα-positive breast tumor samples with matched serum. A comparative MCF-7 xenograft murine model was utilized to determine the role of IL-6 in estrogen-supplemented ERα-positive breast cancer to assess the efficacy of anti-IL-6 therapy in vivo.

Results

In eight of nine ERα-positive breast cancer cell lines, recombinant IL-6 increased phosphorylation of tyrosine 705 of STAT3. Differential gene expression analysis identified 17 genes that could be used to determine IL-6 pathway activation by combining their expression intensity into a pathway activation score. The gene signature included a variety of genes involved in immune cell function and migration, cell growth and apoptosis, and the tumor microenvironment. Validation of the IL-6 gene signature in 36 matched human serum and ERα-positive breast tumor samples showed that patients with a high IL-6 pathway activation score were also enriched for elevated serum IL-6 (≥10 pg/mL). When human IL-6 was provided in vivo, MCF-7 cells engrafted without the need for estrogen supplementation, and addition of estrogen to IL-6 did not further enhance engraftment. Subsequently, we prophylactically treated mice at MCF-7 engraftment with siltuximab, fulvestrant, or combination therapy. Siltuximab alone was able to blunt MCF-7 engraftment. Similarly, siltuximab alone induced regressions in 90% (9/10) of tumors, which were established in the presence which were established in the presence of hMSC expressing human IL-6 and estrogen.

Conclusion

Given the established role for IL-6 in ERα-positive breast cancer, these data demonstrate the potential for anti-IL-6 therapeutics in breast cancer.

Effect of CH-35, a novel anti-tumor colchicine analogue, on breast cancer cells overexpressing the βIII isotype of tubulin

The subunit protein of microtubules is tubulin, which has been the target for some of the most successful and widely used anti-tumor drugs. Most of the drugs that target tubulin bind to the β subunit. There are many isotypes of β-tubulin and their distributions differ among different tissues. The βIII isotype is over-expressed in many tumors, particularly those that are aggressive, metastatic, and drug resistant. We have previously reported the design and synthesis of a series of compounds to fit the colchicine site on βIII but not on the other isotypes. In the current study, we tested the toxicity and the anti-tumor activity of one of these compounds, CH-35, on the human breast tumor MDA-MB-231 over-expressing βIII in a xenogeneic mouse model. We found that CH-35 was as toxic as Taxol® in vivo. Although the βIII-over-expressing cells developed into very fast-growing tumors, CH-35 was more effective against this tumor than was Taxol. Our results suggest that CH-35 is a promising candidate for future drug development.

Analysis of somatostatin receptor 2A immunohistochemistry, RT-qPCR, and in vivo PET/CT data in patients with pancreatic neuroendocrine neoplasm

OBJECTIVE

Gallium 68 somatostatin receptor (SSTR) positron emission tomography/computed tomography (PET/CT) is one of the most sensitive imaging methods for pancreatic neuroendocrine tumors. The aim of the study was to correlate the receptor density generated from the static PET/CT (maximum standard uptake values [SUVmax], mean standard uptake values [SUVmean]) with subtype 2A SSTR (SSTR2A) immunohistochemistry and reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) gene-expression data.

METHODS

Thirty-nine tumor specimens (17 primary pancreatic tumors [PTs], 22 metastases [MTS]) of 19 patients with PET/CT scans preoperatively were evaluated. Subtype 2A SSTR expression was quantified immunohistochemically (immunoreactive score [IRS]) and on messenger RNA (mRNA) level by RT-qPCR.

RESULTS

The PT and MTS did not differ significantly in their SUVmax (P = 0.07) but displayed a dissimilarity with respect to their SSTR2A expression (mean [SD] IRS PT, 8.8 [3.6] vs mean [SD] IRS MTS, 5.1 [4.5]; P = 0.02).The SUVmean was highly significantly correlated to SSTR2A mRNA expression (C = 0.85, P < 0.001) and moderately to SSTR2A protein expression (C = 0.53, P = 0.05). Moreover, the SUVmax correlated moderately with SSTR2A protein expression (C = 0.44, P = 0.03) and mRNA expression (C = 0.64, P = 0.042).

CONCLUSIONS

The SUVmax and SUVmean are reliable ex vivo parameters for in vivo quantification of SSTR expression in pancreatic neuroendocrine tumors. Both immunohistochemistry and RT-qPCR are comparable methods for SSTR2A quantification. The PT and MTS differ significantly in their SSTR2A expression. This fact should be taken into account when treating patients with somatostatin analogs or peptide receptor radionuclide therapy.

Comparison of immunoreactive score, HER2/neu score and H score for the immunohistochemical evaluation of somatostatin receptors in bronchopulmonary neuroendocrine neoplasms

AIMS

Due to the growing number of somatostatin receptor (SSTR) targeting analogues and radiopeptides used for the diagnosis and therapy of neuroendocrine neoplasms (NEN), the assessment of SSTR subtype status has increasingly gained predictive value. In pathology, the SSTR protein levels are detected routinely by immunohistochemistry (IHC); however, a lack of a standardized evaluation system persists. Thus, in the present investigation, three well-established semi-quantitative scoring systems [immunoreactive score (IRS), human epidermal growth factor receptor 2 (HER2)/neu score, H score] used commonly for SSTR-IHC evaluation in NEN were compared.

METHODS AND RESULTS

A total of 240 formalin-fixed, paraffin-embedded tumour samples from 90 patients with bronchopulmonary NEN were examined by IHC and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) for SSTR1, 2A, 3, 4 and 5 expression. Using both methods, SSTR1, 2A and 5 were the most frequently expressed subtypes. For all SSTR subtypes, all three scores correlated well with each other and with qRT-PCR data. However, the IRS was the most meaningful score with the best correlation to mRNA levels.

CONCLUSIONS

Because a unified IHC scoring system for SSTR analysis is needed urgently to optimize the theranostics of NEN, among the scores tested, the IRS seems to be the most suitable according to our results. It provides sufficient accuracy combined with high practicability.

Somatostatin receptors in bronchopulmonary neuroendocrine neoplasms: new diagnostic, prognostic, and therapeutic markers

CONTEXT AND OBJECTIVES

Gastroenteropancreatic neuroendocrine neoplasms are known for their overexpression of somatostatin receptors (SSTRs), which provide the molecular basis for diagnostic and therapeutic interventions. In contrast, few data on the SSTR expression profile exist for bronchopulmonary neuroendocrine neoplasms (BP-NEN).

DESIGN AND SETTINGS

A total of 240 formalin-fixed, paraffin-embedded specimens from 26 typical carcinoid (TC), 30 atypical carcinoid (AC), and 34 small cell lung cancer (SCLC) patients were examined retrospectively by immunohistochemistry (IHC) using specific rabbit monoclonal antibodies and evaluated by the immunoreactive score. Adjacent slides from 20 samples of each tumor type were subjected to additional RT-quantitative PCR mRNA analysis.

RESULTS

With different expression patterns, SSTRs were present in most of the tumor sections, at both the protein and mRNA levels. The RT-quantitative PCR data correlated with the IHC scores. SSTR1 was detected in approximately 65% of the TC and AC, but hardly in the SCLC, whereas both SSTR2A and SSTR5 were present in approximately 45% of each entity. Furthermore, the SSTR1 expression level was positively correlated with patient survival.

CONCLUSIONS

Our results suggest that SSTRs can be used as novel diagnostic, prognostic, and therapeutic markers of BP-NEN. The differences in the SSTR expression profile between the three types of BP-NEN may help to set a diagnostic cutoff and predict patient prognosis. Similar to TC and AC, our results also revealed a previously unappreciated high level of SSTR2A expression in SCLC within a subgroup of patients. However, in most cases, pan-somatostatin analogs may represent an additional therapeutic option.

βIII-Tubulin Regulates Breast Cancer Metastases to the Brain

Brain metastases occur in about 10% to 30% of breast cancer patients, which culminates in a poor prognosis. It is, therefore, critical to understand the molecular mechanisms underlying brain metastatic processes to identify relevant targets. We hypothesized that breast cancer cells must express brain-associated markers that would enable their invasion and survival in the brain microenvironment. We assessed a panel of brain-predominant markers and found an elevation of several neuronal markers (βIII-tubulin, Nestin, and AchE) in brain metastatic breast cancer cells. Among these neuronal predominant markers, in silico analysis revealed overexpression of βIII-tubulin (TUBB3) in breast cancer brain metastases (BCBM) and its expression was significantly associated with distant metastases. TUBB3 knockdown studies were conducted in breast cancer models (MDA-Br, GLIM2, and MDA-MB-468), which revealed significant reduction in their invasive capabilities. MDA-Br cells with suppressed TUBB3 also demonstrated loss of key signaling molecules such as β3 integrin, pFAK, and pSrc in vitro. Furthermore, TUBB3 knockdown in a brain metastatic breast cancer cell line compromised its metastatic ability in vivo, and significantly improved survival in a brain metastasis model. These results implicate a critical role of TUBB3 in conferring brain metastatic potential to breast cancer cells.

Identification of reproducible gene expression signatures in lung adenocarcinoma

BACKGROUND

Lung cancer is the leading cause of cancer-related death worldwide. Tremendous research efforts have been devoted to improving treatment procedures, but the average five-year overall survival rates are still less than 20%. Many biomarkers have been identified for predicting survival; challenges arise, however, in translating the findings into clinical practice due to their inconsistency and irreproducibility. In this study, we proposed an approach by identifying predictive genes through pathways.

RESULTS

The microarrays from Shedden et al. were used as the training set, and the log-rank test was performed to select potential signature genes. We focused on 24 cancer-related pathways from 4 biological databases. A scoring scheme was developed by the Cox hazard regression model, and patients were divided into two groups based on the medians. Subsequently, their predictability and generalizability were evaluated by the 2-fold cross-validation and a resampling test in 4 independent datasets, respectively. A set of 16 genes related to apoptosis execution was demonstrated to have good predictability as well as generalizability in more than 700 lung adenocarcinoma patients and was reproducible in 4 independent datasets. This signature set was shown to have superior performances compared to 6 other published signatures. Furthermore, the corresponding risk scores derived from the set were found to associate with the efficacy of the anti-cancer drug ZD-6474 targeting EGFR.

CONCLUSIONS

In summary, we presented a new approach to identify reproducible survival predictors for lung adenocarcinoma, and the identified genes may serve as both prognostic and predictive biomarkers in the future.

High expression of class III β-tubulin in small cell lung carcinoma

Class III β-tubulin (TUBB3) is emerging as a biomarker in a number of cancers. TUBB3 has been shown to be a prognostic indicator of more aggressive disease and a predictor of resistance to taxanes and vinca alkaloids. To date, there is little data on TUBB3 expression in small cell lung carcinoma (SCLC). The primary objective of this study was to determine the expression of TUBB3 in SCLC. Immunohistochemical staining of SCLC tumor specimens was performed using standard procedures. Expression of TUBB3 was determined as a composite of the percentage of malignant cells staining positive and the intensity of staining. Clinical and tumor data for each patient was compared with the degree of TUBB3 expression. A total of 66 SCLCs were evaluable for TUBB3 expression. The majority of specimens (n=56, 85%) had high expression of TUBB3. Only 4.5% (n=3) had low expression of TUBB3. The mean distribution of positive staining for the specimens was 87.3±1.8% (mean ± SE). Specimens from core biopsies were significantly more likely to have high TUBB3 expression when compared with fine needle aspirates (P=0.004). There were no other significant findings when comparing clinical or tumor characteristics. Overall, we found that expression of TUBB3 in SCLC is higher than expected. Innate resistance to microtubule inhibitors, such as the taxanes and vinca alkaloids, may be associated with this finding. Attempts at microtubule inhibition with novel agents may be able to overcome this resistance mechanism. Further evaluation of TUBB3 as a biomarker in SCLC is warranted.

Neoadjuvant doxorubicin/cyclophosphamide followed by ixabepilone or paclitaxel in early stage breast cancer and evaluation of βIII-tubulin expression as a predictive marker

BACKGROUND

This randomized phase II trial was designed to compare the rate of pathologic complete response (pCR) induced by neoadjuvant cyclophosphamide plus doxorubicin (AC) followed by ixabepilone or paclitaxel in women with early stage breast cancer (BC). Expression of βIII-tubulin as a predictive marker was also evaluated.

PATIENTS AND METHODS

Women with untreated, histologically confirmed primary invasive breast adenocarcinoma received four cycles of AC followed by 1:1 randomization to either ixabepilone 40 mg/m2 (3-hour infusion) every 3 weeks for four cycles (n = 148) or weekly paclitaxel 80 mg/m2 (1-hour infusion) for 12 weeks (n = 147). All patients underwent a core needle biopsy of the primary cancer for molecular marker analysis prior to chemotherapy. βIII-Tubulin expression was assessed using immunohistochemistry.

RESULTS

There was no significant difference in the rate of pCR in the ixabepilone treatment arm (24.3%; 90% confidence interval [CI], 18.6-30.8) and the paclitaxel treatment arm (25.2%; 90% CI, 19.4-31.7). βIII-Tubulin-positive patients obtained higher pCR rates compared with βIII-tubulin-negative patients in both treatment arms; however, βIII-tubulin expression was not significantly associated with a differential response to ixabepilone or paclitaxel. The safety profiles of both regimens were generally similar, although neutropenia occurred more frequently in the ixabepilone arm (grade 3/4: 41.3% vs. 8.4%). The most common nonhematologic toxicity was peripheral neuropathy.

CONCLUSIONS

Neoadjuvant treatment of early stage BC with AC followed by ixabepilone every 3 weeks or weekly paclitaxel was well tolerated with no significant difference in efficacy. Higher response rates were observed among βIII-tubulin-positive patients.

βIII-Tubulin: biomarker of taxane resistance or drug target?

INTRODUCTION

βIII-Tubulin (TUBB3) is predominantly expressed in neurons of the central and peripheral nervous systems, while in normal non-neoplastic tissues it is barely detectable. By contrast, this cytoskeletal protein is abundant in a wide range of tumors. βIII-Tubulin is linked to dynamic instability of microtubules (MTs), weakening the effects of agents interfering with MT polymerization. Based on this principle, early studies introduced the classical theory linking βIII-tubulin with a mechanism of counteracting taxane activity and accordingly, prompted its investigation as a predictive biomarker of taxane resistance.

AREAS COVERED

We reviewed 59 translational studies, including cohorts from lung, ovarian, breast, gastric, colorectal and various miscellaneous cancers subject to different chemotherapy regimens.

EXPERT OPINION

βIII-Tubulin functions more as a prognostic factor than as a predictor of response to chemotherapy. We believe this view can be explained by βIII-tubulin's association with prosurvival pathways in the early steps of the metastatic process. Its prognostic response increases if combined with additional biomarkers that regulate its expression, since βIII-tubulin can be expressed in conditions, such as estrogen exposure, unrelated to survival mechanisms and without any predictive activity. Additional avenues for therapeutic intervention could emerge if drugs are designed to directly target βIII-tubulin and its mechanism of regulation.

Sample parameters affecting the clinical relevance of RNA biomarkers in translational breast cancer research

In the frame of translational breast cancer research, eligibility criteria for formalin-fixed paraffin-embedded tissue (FFPE) material processing for gene expression studies include tumor cell content (TCC) and sample site (primary vs metastatic tumors). Herein we asked whether the observed differences in gene expression between paired samples with respect to TCC and sample site also have different clinical significance. We assessed ESR1, ERBB2, MAPT, MMP7, and RACGAP1 mRNA expression with real time PCR in paired samples before (NMD) and after macrodissection (MD) from 98 primary tumors (P_MD, P_NMD) and 72 metastatic lymph nodes (LN_MD, LN_NMD), as well as from 93 matched P (mP) and LN (mLN). TCC range was 2.5–75 % in the NMD series and 28–98 % in the MD and in the mP/mLN series. The prognostic effect of these markers, individually or in clusters, remained stable between paired P_MD/NMD. In comparison, cluster classification failed in the LN_NMD group with lower TCC. In the mP/mLN cohort, RACGAP1 mRNA expression was of prognostic significance when tested in mLN samples (p < 0.001). Similarly, luminal B, HER2, and triple negative tumors were of dismal prognosis when classified in the LN component of the same series (mLN, overall survival: p = 0.013, p = 0.034, and p = 0.007, respectively). In conclusion, the clinical relevance of the RNA markers examined may be affected by TCC in metastatic LN samples but not in primary tumors, while it differs between primary tumors and matched metastases. These data will facilitate the design of translational studies involving FFPE sample series.

Expression of β-tubulin isotypes in urothelial carcinoma of the bladder

PURPOSE

Our study aims to investigate the expressions of β-tubulin isotypes and their significances in urothelial carcinoma of the bladder (UCB) as altered expression of a specific β-tubulin isotype is associated with chemoresistance and poor prognosis in other malignancies.

MATERIALS AND METHODS

Expression of β-tubulin isotypes was retrospectively examined in 342 UCB samples obtained from 1995 to 2010 by immunohistochemistry.

RESULTS

TUBB1 (307/342, 89.8 %) was most frequently overexpressed in the cytoplasm of UCB cases, followed by TUBB4 (101/342, 29.5 %), TUBB2 (85/342, 24.9 %), and TUBB3 (60/342, 17.5 %). TUBB1 overexpression was associated with older age (p = 0.032), high WHO grade (p = 0.001), and advanced TNM stage (p = 0.006). High levels of TUBB2 expression were associated with high WHO grade (p < 0.001), advanced TNM stage (p < 0.001), and non-papillary growth pattern (p = 0.007). TUBB3 overexpression was related to high WHO grade (p = 0.029). In univariate and multivariate survival analyses, TUBB1 overexpression was associated with poor recurrence-free survival (RFS) rates of all cases (hazard ratio 1.98, p = 0.031) and of the patients with transurethral and/or partial resection (hazard ratio 2.12, p = 0.031). TUBB2 overexpression was correlated with a short RFS of the patients with T2-T4 stages (hazard ratio 3.48, p = 0.007). TUBB3 overexpression was related to a poor RFS of the patients undergoing radical cystectomy (hazard ratio 5.90, p = 0.002).

CONCLUSIONS

High TUBB1, TUBB2, and TUBB3 expressions are associated with unfavorable clinicopathologic factors and are independent prognostic factors for recurrence-free survival of UCB.

The prognostic and predictive value of mRNA expression of vascular endothelial growth factor family members in breast cancer: a study in primary tumors of high-risk early breast cancer patients participating in a randomized Hellenic Cooperative Oncology Group trial

INTRODUCTION

The main prognostic variables in early breast cancer are tumor size, histological grade, estrogen receptor/progesterone receptor (ER/PgR) status, number of positive nodes and human epidermal growth factor receptor 2 (HER2) status. The present study evaluated the prognostic and/or predictive value of vascular endothelial growth factor (VEGF) family members in high-risk early breast cancer patients treated with adjuvant chemo-hormonotherapy.

METHODS

RNA was isolated from 308 formalin-fixed paraffin-embedded primary tumor samples from breast cancer patients enrolled in the HE10/97 trial, evaluating adjuvant dose-dense sequential chemotherapy with epirubicin followed by cyclophosphamide, methotrexate, fluorouracil (CMF) with or without paclitaxel (E-T-CMF versus E-CMF). A fully automated method based on magnetic beads was applied for RNA extraction, followed by one-step quantitative RT-PCR for mRNA analysis of VEGF-A, -B, -C and vascular endothelial growth factor receptor (VEGFR) 1, 2, 3.

RESULTS

With a median follow-up of 8 years, 109 patients (35%) developed a relapse and 80 patients (26%) died. In high VEGF-C and VEGFR1 mRNA expressing tumors, ER/PgR-negative tumors (Fisher's exact test, P = 0.001 and P = 0.021, respectively) and HER2-positive tumors (P <0.001 and P = 0.028, respectively) were more frequent than in low VEGF-C and VEGFR1 expressing tumors, respectively. From the VEGF family members evaluated, high VEGFR1 mRNA expression (above the 75th percentile) emerged as a significant negative prognostic factor for overall survival (OS; hazard ratio (HR) = 1.60, 95% confidence interval (CI): 1.01 to 2.55, Wald's P = 0.047) and disease-free survival (DFS; HR = 1.67, 95% CI: 1.13 to 2.48, P = 0.010), when adjusting for treatment group. High VEGF-C mRNA expression was predictive for benefit from adjuvant treatment with paclitaxel (E-T-CMF arm) for OS (test for interaction, Wald's P = 0.038), while in multivariate analysis the interaction of VEGF-C with taxane treatment was significant for both OS (Wald's P = 0.019) and DFS (P = 0.041) and continuous VEGF-B mRNA expression values for OS (P = 0.019).

CONCLUSIONS

The present study reports, for the first time, that VEGF-C mRNA overexpression, as assessed by qRT-PCR, has a strong predictive value in high-risk early breast cancer patients undergoing adjuvant paclitaxel-containing treatment. Further studies are warranted to validate the prognostic and/or predictive value of VEGF-B, VEGF-C and VEGFR1 in patients treated with adjuvant therapies and to reveal which members of the VEGF family could possibly be useful markers in identifying patients who will benefit most from anti-VEGF strategies.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12611000506998.

Prognostic significance of RACGAP1 mRNA expression in high-risk early breast cancer: a study in primary tumors of breast cancer patients participating in a randomized Hellenic Cooperative Oncology Group trial

PURPOSE

RACGAP1 is a Rac GTPase-activating protein involved in cell growth regulation, cell transformation and metastasis. The aim of the present study was to explore the prognostic and/or predictive significance of RACGAP1 mRNA expression on disease-free survival (DFS) and overall survival (OS) in high-risk early breast cancer patients and compare it to that of Ki67 protein expression and to the Nottingham prognostic index (NPI).

METHODS

A total of 595 high-risk breast cancer patients were treated in a two-arm trial evaluating postoperative dose-dense sequential chemotherapy with epirubicin followed by CMF with or without paclitaxel. RNA was extracted from 314 formalin-fixed paraffin-embedded primary tumor tissue samples followed by one-step quantitative RT-PCR for assessing RACGAP1 mRNA expression.

RESULTS

High RACGAP1 mRNA expression (above the median) was associated with poor DFS (log-rank, p = 0.002) and OS (p < 0.001). High histological grade, as well as high Ki67 protein expression, was more frequent in the high-expression group of RACGAP1. Results of the Cox multivariate regression analysis revealed that high RACGAP1 mRNA expression independently predicted poor overall survival (Wald's p = 0.008). High Ki67 protein expression was also an adverse prognostic factor for death (p = 0.016), while high NPI score values were not.

CONCLUSIONS

High RACGAP1 mRNA expression, as assessed by qRT-PCR, was found to be of adverse prognostic significance in high-risk early breast cancer patients treated with dose-dense sequential chemotherapy. The utility of RACGAP1 mRNA expression in patient selection for treatment with aggressive chemotherapy regimens should be further explored and validated in larger cohorts.

Improved outcome of high-risk early HER2 positive breast cancer with high CXCL13-CXCR5 messenger RNA expression

The CXCL13-CXCR5 is a chemokine axis that is activated in some breast cancers. A total of 321 tissue blocks from a group of patients who received adjuvant, dose-dense chemotherapy for high-risk early breast cancer were examined. Activation of this axis was found to be associated with determinants of poor prognosis but also with improved outcome in the human epidermal growth factor receptor 2 overexpressing subpopulation.

BACKGROUND

Chemokines are important in cell migration and are thought to play a key role in metastasis. We explored the prognostic significance of C-X-C ligand-motif (CXCL) 12, CXCL13, and receptor (CXCR) 5 on disease-free survival (DFS) and overall survival (OS) in early breast cancer.

METHODS

A total of 595 patients with high risk, [corrected] early breast cancer were treated in a 2-arm trial (HE10/97) with dose-dense sequential epirubicin followed by cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) with or without paclitaxel. RNA was extracted from 321 formalin-fixed paraffin-embedded primary tumor tissue samples and quantitative reverse-transcriptase polymerase chain reaction was used to assess messenger RNA (mRNA) expression of CXCL12, CXCL13, and CXCR5; estrogen receptor; progesterone receptor (PgR); microtubule-associated protein tau and human epidermal growth factor receptor 2 (HER2).

RESULTS

CXCL13 and CXCR5 were found to be negatively associated with estrogen receptor and microtubule-associated protein tau mRNA expression and with dense lymphocytic infiltration, and were positively associated with nuclear grade. Only CXCL13 was positively associated with HER2. Multivariate analysis revealed an association between high CXCL13 mRNA expression and improved DFS (hazard ratio [HR] 0.48 [95% CI, 0.25-0.90]; Wald, P = .023) but not OS; whereas high CXCL12 expression was significantly associated with increased OS (HR 0.53 [95% CI, 0.33-0.85]; Wald, P = .009). In the HER2 mRNA overexpressing subgroup, high CXCL13 mRNA expression was associated with improved DFS (P < .001), whereas high CXCR5 was associated with increased DFS and OS (P = .004 and P = .049, respectively).

CONCLUSIONS

The CXCL13-CXCR5 axis is associated with classic determinants of poor prognosis, such as high grade, hormone receptor negativity, and axillary node involvement. Interestingly, this chemokine axis seems to be strongly associated with improved outcome in patients with HER2(+) disease.

High TUBB3 expression, an independent prognostic marker in patients with early non-small cell lung cancer treated by preoperative chemotherapy, is regulated by K-Ras signaling pathway

We assessed the prognostic and predictive value of β-tubulin III (TUBB3) expression, as determined by immunohistochemistry, in 412 non-small cell lung cancer (NSCLC) specimens from early-stage patients who received neoadjuvant chemotherapy (paclitaxel- or gemcitabine-based) in a phase III trial (IFCT-0002). We also correlated TUBB3 expression with K-Ras and EGF receptor (EGFR) mutations in a subset of 208 cryopreserved specimens. High TUBB3 protein expression was associated with nonsquamous cell carcinomas (P < 0.001) and K-Ras mutation (P < 0.001). The 127 (30.8%) TUBB3-negative patients derived more than 1 year of overall survival advantage, with more than 84 months median overall survival versus 71.7 months for TUBB3-positive patients [HR, 1.58; 95% confidence interval (CI), 1.11-2.25)]. This prognostic value was confirmed in multivariate analysis (adjusted HR for death, 1.51; 95% CI, 1.04-2.21; P = 0.031) with a bootstrapping validation procedure. TUBB3 expression was associated with nonresponse to chemotherapy (adjusted HR, 1.31; 95% CI, 1.01-1.70; P = 0.044) but had no predictive value (taxane vs. gemcitabine). Taking account of these clinical findings, we further investigated TUBB3 expression in isogenic human bronchial cell lines only differing by K-Ras gene status and assessed the effect of K-Ras short interfering RNA (siRNA) mediated depletion, cell hypoxia, or pharmacologic inhibitors of K-Ras downstream effectors, on TUBB3 protein cell content. siRNA K-Ras knockdown, inhibition of RAF/MEK (MAP-ERK kinase) and phosphoinositide 3-kinase (PI3K)/AKT signaling, and hypoxia were shown to downregulate TUBB3 expression in bronchial cells. This study is the first one to identify K-Ras mutations as determinant of TUBB3 expression, a chemoresistance marker. Our in vitro data deserve studies combining standard chemotherapy with anti-MEK or anti-PI3K drugs in patients with TUBB3-overexpressing tumors.

Stathmin expression and its relationship to microtubule-associated protein tau and outcome in breast cancer

BACKGROUND

Microtubule-associated proteins (MAPs) endogenously regulate microtubule stability. Here, the prognostic value of stathmin, a destabilizing protein, was assessed in combination with MAP-tau, a stabilizing protein, in order to evaluate microtubule stabilization as a potential biomarker.

METHODS

Stathmin and MAP-tau expression levels were measured in a breast cancer cohort (n = 651) using the tissue microarray format and quantitative immunofluorescence (AQUA) technology, then correlated with clinical and pathological characteristics and disease-free survival.

RESULTS

Univariate Cox proportional hazard models indicated that high stathmin expression predicts worse overall survival (hazard ratio [HR] = 1.48; 95% confidence interval [CI] = 1.119-1.966; P = .0061). Survival analysis showed 10-year survival of 53.1% for patients with high stathmin expression versus 67% for low expressers (log-rank, P < .003). Cox multivariate analysis showed high stathmin expression was independent of age, menopausal status, nodal status, nuclear grade, tumor size, and estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression (HR = 1.19; 95% CI = 1.03-1.37; P = .01). The ratio of MAP-tau to stathmin expression showed a positive correlation to disease-free survival (HR = 0.679; 95% CI = 0.517-0.891; P = .0053) with a 10-year survival of 65.4% for patients who had a high ratio of MAP-tau to stathmin versus 52.5% 10-year survival rate for those with a low ratio (log-rank, P = .0009). Cox multivariate analysis showed the ratio of MAP-tau to stathmin was an independent predictor of overall survival (HR = 0.609; 95% CI = 0.422-0.879; P = .008).

CONCLUSIONS

Low stathmin and high MAP-tau are associated with increased microtubule stability and better prognosis in breast cancer.

Prognostic significance of UBE2C mRNA expression in high-risk early breast cancer. A Hellenic Cooperative Oncology Group (HeCOG) Study

BACKGROUND

The ubiquitin-proteasome system (UPS) plays a pivotal role in tumorigenesis. Components of the UPS have recently been implicated in breast cancer progression. In the present study, we sought to explore the prognostic and/or predictive significance of UBE2C messenger RNA (mRNA) expression on disease-free survival (DFS) and overall survival (OS) in high-risk operable breast cancer patients.

METHODS

Five hundred and ninety-five high-risk breast cancer patients were treated in a two-arm trial evaluating postoperative, dose-dense sequential chemotherapy with epirubicin followed by CMF (cyclophosphamide, methotrexate and 5-fluorouracil) with or without paclitaxel (Taxol). RNA was extracted from 313 formalin-fixed primary tumor tissue samples followed by one-step quantitative RT-PCR for assessment of mRNA expression of UBE2C.

RESULTS

High UBE2C mRNA expression was associated with poor DFS (Wald's P = 0.003) and OS (Wald's P = 0.005). High tumor grade, as well as high Ki67 protein expression, was more frequent in the high-expression group of UBE2C. Results of the Cox multivariate regression analysis revealed that high UBE2C mRNA expression remained an independent adverse prognostic factor for relapse (P = 0.037) and death (P = 0.05).

CONCLUSIONS

High UBE2C mRNA expression was found to be of adverse prognostic significance in high-risk breast cancer patients. These findings need to be validated in larger cohorts.