Measuring β-tubulin III, Bcl-2, and ERCC1 improves pathological complete remission predictive accuracy in breast cancer

ERCC1 is a potential biomarker for predicting prognosis, immunotherapy, chemotherapy efficacy, and expression validation in HER2 over-expressing breast cancer

Objective

To investigate the relationship between Excision repair cross-complementation 1 (ERCC1) expression, clinicopathological features, and breast cancer prognosis in patients treated with trastuzumab. Further, we aim to explore the immune status of ERCC1 in breast cancer.

Methods

The data were retrieved from publicly available databases like the Cancer Genome Atlas, Therapeutically Applicable Research to Generate Effective Treatments, and the Genotype-Tissue Expression. The data was used to perform differential expression analyses between tumor and normal tissues in pan-cancers, immune-related analysis, homologous recombination deficiency (HRD), tumor mutation burden, and microsatellite instability. A total of 210 patients with HER2 over-expressing breast cancer from the Fourth Hospital of Hebei Medical University between January 2013 to December 2015 were enrolled in the study. Ten adjacent normal tissues were used to study the expression pattern of ERCC1 in normal tissues. Immunohistochemistry was performed to study ERCC1 expression and immune cell infiltration in different status of ERCC1 expression. Further, the correlation between ERCC1 expression, immune cell infiltration clinicopathological features, and the prognosis of patients with breast cancer was analyzed.

Results

The immune analysis revealed a significant correlation between CD8+ T cell, CD4+ T cell, T helper cell, macrophages, mast cells, and ERCC1 expression. Spearman analysis show that ERCC1 expression is related to macrophages and T cells. A close correlation was observed between increased ERCC1 expression and high tumor immune dysfunction and exclusion (TIDE) score as well as HRD. The results revealed a significant correlation among ERCC1, chemotherapy and estrogen receptor (ER; P < 0.05) expression. Univariate survival analysis revealed a significant correlation (P < 0.05) between that ERCC1 and ER expression, blood vessel invasion, and disease-free survival (DFS). ERCC1 and ER expression, tumor size, blood vessel invasion, pathological type, and lymph node metastases significantly correlated (P < 0.05) with overall survival in patients. Multivariate regression analysis revealed that ERCC1 expression and chemotherapy were independent factors that influence DFS. ERCC1 expression and vascular tumor thrombus were independent influencing factors that influence OS.

Conclusion

A correlation was observed between high ERCC1 expression and poor patient prognosis. High ERCC1 expression also influences the efficacy of immunotherapy and chemotherapy.

Oxidative stress genes in patients with esophageal squamous cell carcinoma: construction of a novel prognostic signature and characterization of tumor microenvironment infiltration

Background

Oxidative stress plays an important role in the progression of various types of tumors. However, its role in esophageal squamous cell carcinoma (ESCC) has seldom been explored. This study aimed to discover prognostic markers associated with oxidative stress in ESCC to improve the prediction of prognosis and help in the selection of effective immunotherapy for patients.

Results

A consensus cluster was constructed using 14 prognostic differentially expressed oxidative stress-related genes (DEOSGs) that were remarkably related to the prognosis of patients with ESCC. The infiltration levels of neutrophils, plasma cells, and activated mast cells, along with immune score, stromal score, and estimated score, were higher in cluster 1 than in cluster 2. A prognostic signature based on 10 prognostic DEOSGs was devised that could evaluate the prognosis of patients with ESCC. Calculated risk score proved to be an independent clinical prognostic factor in the training, testing, and entire sets. P53 signaling pathway was highly enriched in the high-risk group. The calculated risk score was positively related to the infiltration levels of resting mast cells, memory B cells, and activated natural killer (NK) cells and negatively associated with the infiltration levels of M1 and M2 macrophages. The relationship between clinical characteristics and risk score has not been certified. The half-maximal inhibitory concentration (IC50) values for sorafenib and gefitinib were lower for patients in the low-risk group.

Conclusion

Our prognostic signature based on 10 prognostic DEOSGs could predict the disease outcomes of patients with ESCC and had strong clinical value. Our study improves the understanding of oxidative stress in tumor immune microenvironment (TIME) and provides insights for developing improved and efficient immunotherapy strategies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12859-022-04956-9.

Predictive and Prognostic Significance of mRNA Expression and DNA Copies Aberrations of ERCC1, RRM1, TOP1, TOP2A, TUBB3, TYMS, and GSTP1 Genes in Patients with Breast Cancer

Increasingly, many researchers are focusing on the sensitivity in breast tumors (BC) to certain chemotherapy drugs and have personalized their research based on the assessment of this sensitivity. One such personalized approach is to assess the chemotherapy’s gene expression, as well as aberrations in the number of DNA copies—deletions and amplifications with the ability to have a significant effect on the gene’s activity. Thus, the aim of this work was to study the predictive and prognostic significance of the expression and chromosomal aberrations of eight chemosensitivity genes in breast cancer patients. Material and methods. The study involved 97 patients with luminal B breast cancer IIB–IIIB stages. DNA and RNA were isolated from samples of tumor tissue before and after treatment. Microarray analysis was performed for all samples on high-density microarrays (DNA chips) of Affymetrix (USA) CytoScanTM HD Array and Clariom™ S Assay, human. Detection of expression level of seven chemosensitivity genes—RRM1, ERCC1, TOP1, TOP2a, TUBB3, TYMS, and GSTP1—was performed using PCR real-time (RT-qPCR). Results. The expression of the RRM1 (AC scheme), TOP2α, TYMS, and TUBB3 genes in patients with an objective response to treatment (complete and partial regression) is higher than in patients with stabilization and progression (p < 0.05). According to our results, the presence of a high level of GSTP1 in a tumor biopsy is associated with the low efficiency of the NAC CP scheme (p = 0.05). The presence of RRM1 deletion is associated with complete and partial regression, as for the TOP1 and TUBB3 genes (p < 0.05). Higher rates of metastatic survival are associated with a high level of expression and amplification of the GSTP1 gene (log-rank test p = 0.02 and p = 0.05). Conclusion. Thus, a complex assessment of the chemotherapy’s gene expression is important not only for understanding the heterogeneity and molecular biology of breast cancer but also to obtain a more accurate disease prognosis.

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.

Individualized chemotherapy guided by the expression of ERCC1, RRM1, TUBB3, TYMS and TOP2A genes versus classic chemotherapy in the treatment of breast cancer: A comparative effectiveness study

ERCC1, RRM1, TUBB3, TYMS and TOP2A genes have been shown to be associated with drug resistance in various types of tumors; however, their roles in breast cancer chemotherapy have not been fully validated. In the present study, 140 well-matched patients with breast cancer, comprising 70 patients receiving individualized chemotherapy and 70 receiving classic chemotherapy, were analyzed. In the individualized chemotherapy group, the mRNA expression levels of ERCC1, RRM1, TUBB3, TYMS and TOP2A in breast cancer tissues were measured using multiplex branched DNA liquidchip technology prior to chemotherapy; an individualized chemotherapy regimen was developed for each patient according to the results. As a control, patients in the classic chemotherapy group received a docetaxel + epirubicin + cyclophosphamide regimen. Survival analyses were performed using the Kaplan-Meier method. The prognostic factors for disease-free survival (DFS) and overall survival (OS) in the patients were identified via Cox's proportional hazards regression model. Adverse reactions were evaluated according to the National Cancer Institute Common Toxicity Criteria 4. Compared with the classic chemotherapy group, the DFS and OS of the individualized chemotherapy group were significantly longer (DFS, 77.4 vs. 67.1 months, P=0.039; OS, 81.4 vs. 75.4 months, P=0.031), and the incidence of grade 2 or 3 palpitations and chest tightness was lower (12.9 vs. 27.1%, P=0.035). The chemotherapy strategy guided by genetic detection was an independent protection factor for DFS [hazard ratio (HR)=0.389, 95% confidence interval (CI): 0.153, 0.989, P=0.047], but not an independent protection factor for OS (HR=0.340, 95% CI: 0.107, 1.078, P=0.067). The results indicate that the combined detection of ERCC1, RRM1, TUBB3, TYMS and TOP2A gene expression and use of the results to guide individualized chemotherapy can improve treatment efficacy and reduce unnecessary toxicity.

Measurement of molecular biomarkers that predict the tumor response in estrogen receptor-positive breast cancers after dose-dense (biweekly) paclitaxel/carboplatin neoadjuvant chemotherapy

The aim of this study was to determine the predictive value of the clinical and histopathological characteristics of estrogen receptor (ER)-positive patients treated with dose-dense paclitaxel/carboplatin neoadjuvant chemotherapy (NCT). Pathological complete response (pCR) and the change in tumor size between pre- and post-NCT were used to evaluate the tumor response.85 ER-positive breast cancer patients who were treated with dose-dense (biweekly) paclitaxel/carboplatin NCT were analyzed with respect to the expression of progesterone receptor (PgR), Tau, Ki67, human epidermal growth factor receptor 2 (HER2), and Bcl-2 by immunohistochemistry (IHC). These data were used to determine whether these biomarkers could predict the tumor response. A univariate analysis showed that the patients who tested positive for HER2 expression (56.00% vs 11.67%, p<0.01), negative for Tau expression (41.94% vs 14.81%, p=0.005), negative for Bcl-2 expression (46.43% vs 14.04%, p<0.01) and had smaller (≤2 cm) tumors (45.00% vs 18.46%, p=0.02) were associated with higher pCR rates. A multivariate analysis showed that a HER2-positive status (OR: 6.244; 95%CI: 1.734-22.487; p=0.005), Bcl-2-negative status (OR: 0.236; 95%CI: 0.064-0.869; p=0.030) and smaller (≤2 cm) tumor sizes (OR: 0.188; 95%CI: 0.046-0.767; p=0.020) are independent predictors of pCRs. The tumor sizes were significantly reduced in patients with HER2-positive, Tau-negative, Bcl-2-negative and high Ki67 index breast cancer. In conclusion, Bcl-2 negative, HER2-positive and smaller (≤2 cm) tumor sizes are independent predictors of pCR in ER-positive patients treated with dose-dense (biweekly) paclitaxel/carboplatin NCT. This study is registered with ClinicalTrials.gov (NCT0205986).

High-level βIII-tubulin overexpression occurs in most head and neck cancers but is unrelated to clinical outcome

BACKGROUND

βIII-tubulin (TUBB3) is an isotype of microtubules, which are involved in crucial cellular roles including maintenance of cell shape, intracellular transport, and mitosis. Overexpression of TUBB3 was found to be associated with poor prognosis and resistance to tubulin-binding drugs and in several solid tumors including head and neck squamous cell carcinomas (HNSCC). Considering the potential high importance of a prognostic biomarker in these cancers, this study aimed to investigate the clinical relevance of immunohistochemical TUBB3 expression in HNSCC.

METHODS

Tissue microarray (TMA) sections containing samples from 667 cancers of oral cavity, oro- and hypopharynx, and larynx for which follow-up data were available were analyzed for TUBB3 expression by immunohistochemistry.

RESULTS

Over 90% of our analyzed cancers showed unequivocal cytoplasmic TUBB3 expression. Staining was considered weak in 69 (15.5%), moderate in 149 (33.5%), and strong in 188 (42.2%) of cancers. The frequent TUBB3 overexpression showed no significant correlation with pathological grading, tumor stage, nodal status, or surgical margin and had no impact on patient outcomes.

CONCLUSION

Despite lacking prognostic utility in HNSCC, the remarkable high prevalence of TUBB3 expression in HNSCC emphasizes its putative relevance as a target for future drugs targeting TUBB3.

ERCC1 Expression in Metastatic Triple Negative Breast Cancer Patients Treated with Platinum-Based Chemotherapy

Background: Possible targeted therapies for metastatic triple negative breast cancer (TNBC) include cytotoxic chemotherapy that causes interstrand breaks (platinum-based drugs). The excision repair cross-complementation 1 (ERCC1) enzyme plays an essential role in the nucleotide excision repair pathway, removing platinum-induced DNA adducts and contributing to cisplatin resistance. Detecting ERCC1 overexpression is important in considering treatment options for metastatic TNBC, including individualized approaches to therapy, and may facilitate improved responses or reduction of unnecessary toxicity. We hypothesized that assigning cisplatin based on pretreatment ERCC1 expression would improve response and survival. This study was conducted to assess the impact of ERCC1 expression on PFS, OS and response rates in metastatic triple negative breast cancer patients treated with platinum-based chemotherapy. Methods: From June 2012 to November 2013, 52 metastatic triple negative breast cancer patients were enrolled. ERCC1 protein expression was detected from pretreatment biopsies by Immunohistochemistry. All patients received cisplatin plus paclitaxel. The primary end point was the impact of ERCC1 expression on PFS and OS. Results: 34 patients (65.4%) showed positive ERCC1 expression while 18 (34.6%) proved negative. Positive ERCC1 expression was associated with short PFS (median, 5 months vs. 7 months; P = 0.043), short OS (median, 9 months vs. 11 months; P = 0.033) and poor response to cisplatin based chemotherapy (P = 0.046). Conclusions: This prospective study further validated ERCC1 as a reliable biomarker for customized chemotherapy in metastatic triple negative breast cancer patients. High expression of ERCC1 was thereby fond to be significantly associated with poor outcome in patients treated with platinum based chemotherapy.

Class III β-Tubulin in Colorectal Cancer: Tissue Distribution and Clinical Analysis of Chinese Patients

BACKGROUND Class III β-tubulin (βIII-tubulin) has been reported to express at the invasive margin of colorectal cancer. The present study aimed to investigate the clinical implication of βIII-tubulin expression at the invasive margin of colorectal cancer. MATERIAL AND METHODS We recruited 111 patients with surgically resected colorectal carcinoma for bIII-tubulin expression analysis. The cases with bIII-tubulin-positive tumor cells found only in the invasive front tumor area were assigned to the invasive front group, while the remaining cases were all assigned to the non-invasive front group. Clinical analysis of βIII-tubulin and other clinical data was performed. RESULTS The positive staining rates and staining intensity of bIII-tubulin were significantly different between the invasive and non-invasive front groups (p=0.001 and p=0.006), and there was a significant difference in tumor differentiation between the 2 groups (p=0.032). In the non-invasive front group, staining intensity of bIII-tubulin was significantly associated with positive staining rates and lymphatic metastasis (p<0.001 and p=0.048). CONCLUSIONS Our data showed the tissue distribution of bIII-tubulin expression at invasive margin or diffuse distribution. Expression of bIII-tubulin was correlated with tumor differentiation and lymphatic metastasis, suggesting a potential role of bIII-tubulin in tumor differentiation and metastasis. This study may shed light on bIII-tubulin as a novel potential molecular target for a new anti-cancer drug.

ERCC1 and telomere status in breast tumours treated with neoadjuvant chemotherapy and their association with patient prognosis

Dysfunctional telomeres and DNA damage repair (DDR) play important roles in cancer progression. Studies have reported correlations between these factors and tumour aggressiveness and clinical outcome in breast cancer. We studied the characteristics of telomeres and expression of ERCC1, a protein involved in a number of DNA repair pathways and in telomere homeostasis, to assess their prognostic value, alone or in combination, in 90 residual breast tumours after treatment with neoadjuvant chemotherapy (NCT). ERCC1 status was investigated at different molecular levels (protein and gene expression and gene copy‐number variations) by immunohistochemistry, qRT‐PCR and quantitative multiplex fluorescent‐PCR (QMF‐PCR). A comprehensive analysis of telomere characteristics was performed using qPCR for telomere length and qRT‐PCR for telomerase (hTERT), tankyrase 1 (TNKS) and shelterin complex (TRF1, TRF2, POT1, TPP1, RAP1 and TIN2) gene expression. Short telomeres, high hTERT and TNKS expression and low ERCC1 protein expression were independently associated with worse survival outcome. Interestingly, ERCC1 gains and losses correlated with worse disease‐free (p = 0.026) and overall (p = 0.043) survival as compared to survival of patients with normal gene copy‐numbers. Unsupervised hierarchical clustering of all ERCC1 and telomere parameters identified four subgroups with distinct prognosis. In particular, a cluster combining low ERCC1, ERCC1 gene alterations, dysfunctional telomeres and high hTERT and a cluster with high TNKS and shelterin expression correlated with poor disease‐free (HR= 5.41, p= 0.0044) and overall survival (HR= 6.01, p= 0.0023) irrespective of tumour stage and grade. This comprehensive study demonstrates that telomere dysfunction and DDR can contribute synergistically to tumour progression and chemoresistance. These parameters are predictors of clinical outcome in breast cancer patients treated with NCT and could be useful clinically as prognostic biomarkers to tailor adjuvant chemotherapy post‐NCT.

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.

An Optimization-Driven Analysis Pipeline to Uncover Biomarkers and Signaling Paths: Cervix Cancer

Establishing how a series of potentially important genes might relate to each other is relevant to understand the origin and evolution of illnesses, such as cancer. High-throughput biological experiments have played a critical role in providing information in this regard. A special challenge, however, is that of trying to conciliate information from separate microarray experiments to build a potential genetic signaling path. This work proposes a two-step analysis pipeline, based on optimization, to approach meta-analysis aiming to build a proxy for a genetic signaling path.

β3-tubulin is a good predictor of sensitivity to taxane-based neoadjuvant chemotherapy in primary breast cancer

The objective of this study was to explore the relationship between β3-tubulin expression and sensitivity to taxane-based neoadjuvant chemotherapy in primary breast cancer patients. A total of 48 local advanced breast cancer patients that received taxane-containing neoadjuvant chemotherapy were studied. The levels of β3-tubulin expression were tested by immunohistochemistry before chemotherapy and at the end of cycles 2, 4 and 6. The correlation between the efficacy of the chemotherapy and β3-tubulin expression and changes in β3-tubulin expression over the course of chemotherapy was examined. β3-tubulin protein expression before chemotherapy was significantly and negatively correlated with the response rate. The overall response rate was 31.8 % in the high β3-tubulin expression group, whereas it was 84.6 % in the low β3-tubulin expression group. At the end of cycles 2, 4 and 6 during the treatment course, the average expression rates of β3-tubulin were showed an increasing trend with β3-tubulin expression level at the end of cycle 4 being significantly different from that before chemotherapy. Nine patients that had a low β3-tubulin expression level preneoadjuvant chemotherapy changed to a high β3-tubulin expression level postneoadjuvant chemotherapy, and they had lower response rate than patients with consistent low. In conclusion, β3-tubulin is a good predictor of chemosensitivity to taxane for breast cancer, and the change of its expression level during chemotherapy may be an important cause of secondary resistance to taxane. Detection of β3-tubulin expression before and throughout the chemotherapy will help with selection of the chemotherapy treatment plan.

βIII-tubulin overexpression is an independent predictor of prostate cancer progression tightly linked to ERG fusion status and PTEN deletion

Evidence suggests that class III β-tubulin (βIII-tubulin) may represent a prognostic and predictive molecular marker in prostate cancer. βIII-Tubulin expression was determined by IHC in 8179 prostate cancer specimens in a TMA format. Results were compared with tumor phenotype, biochemical recurrence, v-ets avian erythroblastosis virus E26 oncogene homolog (ERG) status, and deletions on PTEN, 3p13, 5q21, and 6q15. βIII-Tubulin expression was detectable in 25.6% of 8179 interpretable cancers. High βIII-tubulin expression was strongly associated with both TMPRSS2:ERG rearrangement and ERG expression (P < 0.0001 each). High βIII-tubulin expression was tightly linked to high Gleason grade, advanced pT stage, and early prostate-specific antigen (PSA) recurrence in all cancers (P < 0.0001 each), but also in the subgroups of ERG-negative and ERG-positive cancers. When all tumors were analyzed, the prognostic role of βIII-tubulin expression was independent of Gleason grade, pT stage, pN stage, surgical margin status, and preoperative PSA. Independent prognostic value became even more evident if the analysis was limited to preoperatively available features, such as biopsy specimen Gleason grade, preoperative PSA, cT stage, and βIII-tubulin expression (P < 0.0001 each). βIII-Tubulin expression was associated with PTEN (P < 0.0001) when all tumors were analyzed, but also in the subgroups of ERG-negative and ERG-positive cancers. βIII-Tubulin expression is an independent prognostic parameter. The significant associations with key genomic alterations of prostate cancer, such as TMPRSS2:ERG fusions and PTEN deletions, suggest interactions with several pivotal pathways involved in prostate cancer.

Bcl-2 expression predicts sensitivity to chemotherapy in breast cancer: a systematic review and meta-analysis

Background

Numerous studies have yielded inconclusive results regarding the relationship between anti-apoptotic protein Bcl-2 expression and the sensitivity to chemotherapy in the patients with breast cancer. The purpose of the current study was therefore to elaborate their relationship.

Methods, findings

A total of 23 previously published eligible studies involving 2,467 cases were identified and included in this meta-analysis. Negative Bcl-2 expression was associated with good chemotherapy response in breast cancer patients (total objective response [OR]: risk ratio [RR] = 1.16, 95% confidence interval [CI] = 1.02-1.32, p = 0.026; total complete response [CR]: RR = 1.67, 95% CI = 1.24-2.24, p = 0.001; pathological CR: RR = 1.92, 95% CI = 1.38-2.69, p < 0.001). In further stratified analyses, this association remained for sub-groups of response in neoadjuvant chemotherapy setting, especially pathological CR. Besides, negative Bcl-2 expression was significantly associated with good OR and pathological CR in anthracycline-based chemotherapy subgroup. Furthermore, there were significant links between negative Bcl-2 expression and taxane-based chemotherapy with pathological CR, but not OR.

Conclusion

The results of the present meta-analysis suggest that Bcl-2 expression is a predictive factor for chemotherapy sensitivity in breast cancer patients. They could also potentially benefit further clinical treatment for breast cancers.

Microtubule-Associated Protein Tau, α-Tubulin and βIII-Tubulin Expression in Breast Cancer

Background

The microtubule-associated protein Tau binds to both inner and outer surfaces of microtubules, leading to tubulin assembly and microtubule stabilization. The aim of this study was to evaluate the significance of Tau, α-tubulin, and βIII-tubulin expression in breast carcinoma and to assess their relationships with disease progression in the context of taxane treatment.

Methods

Immunohistochemical expressions of Tau, α-tubulin, and βIII-tubulin were assessed in 183 breast cancer cases. Expression was correlated with clinicopathologic parameters, disease progression and overall survival.

Results

Tau expression was correlated with lymph node metastasis and estrogen receptor (ER) positivity (p=.003 and p<.001, respectively). Loss of α-tubulin was significantly correlated with distant metastasis (p=.034). Loss of βIII-tubulin was correlated with lymph node metastasis and ER positivity (p=.004 and p<.001, respectively). In taxane-treated cases, Tau expression and loss of α-tubulin and βIII-tubulin expression were related to disease progression (p=.001, p=.028, and p=.030, respectively). Tau expression was associated with a worse survival rate in taxane-treated patients (p=.049).

Conclusions

Tau expression and loss of α-tubulin and βIII-tubulin expression were correlated with aggressive behavior in taxane-treated breast cancer. Further evaluation of Tau, α-tubulin and βIII-tubulin may be useful in predicting clinical behavior and seeking therapeutic measures in taxane-based chemotherapy for breast cancer.

Tubulin: an example of targeted chemotherapy

Anticancer drugs directed against the microtubule, including taxanes and vinca alkaloids, have been the backbone of many chemotherapy regimes for decades. These drugs have, however, significant limitations, which have prompted the development of novel microtubule targeting agents (MTAs). This article will discuss MTAs for anticancer therapies and recent debates regarding their mechanisms of action. Furthermore, the limitations of taxanes, including hypersensitivity reactions, neurotoxicity, drug resistance and lack of validated biomarkers to guide therapy will be discussed, all of which have driven the development of novel agents. The mechanisms of action and drug development of new generations of MTAs will also be outlined. Agents demonstrating utility in Phase III clinical trials, including eribulin, ixabepilone, cabazitaxel and trastuzumab-DM1 will be highlighted, as well as novel agents currently in development and future directions for MTAs.

Clinicopathological significance of ERCC1 expression in breast cancer

The excision repair cross-complementation 1 (ERCC1) enzyme plays an essential role in the nucleotide excision repair pathway and is associated with resistance to platinum-based chemotherapy in different types of cancer. The aim of the present study was to evaluate the clinicopathological significance of ERCC1 expression in breast cancer patients. We analyzed the immunohistochemical expression of ERCC1 in a tissue microarray from 135 primary breast carcinomas and correlated the immunohistochemical findings with clinicopathological factors and outcome data. ERCC1 expression analysis was available for 109 cases. In this group, 58 (53.2%) were positive for ERCC1. ERCC1-positive expression was correlated with smaller tumor size (P=0.007) and with positivity for estrogen receptor (P=0.040), but no correlation was found with other clinicopathological features. Although not statistically significant, triple negative breast cancers were more frequently negative for ERCC1 (61.5% of the cases) compared to the non-triple negative breast cancer cases (41.5%). In conclusion, ERCC1 expression correlated significantly with favorable prognostic factors, such as smaller tumor size and ER-positivity, suggesting a possible role for ERCC1 as a predictive and/or prognostic marker in breast cancer.

Identification of potential biomarkers from microarray experiments using multiple criteria optimization

Microarray experiments are capable of determining the relative expression of tens of thousands of genes simultaneously, thus resulting in very large databases. The analysis of these databases and the extraction of biologically relevant knowledge from them are challenging tasks. The identification of potential cancer biomarker genes is one of the most important aims for microarray analysis and, as such, has been widely targeted in the literature. However, identifying a set of these genes consistently across different experiments, researches, microarray platforms, or cancer types is still an elusive endeavor. Besides the inherent difficulty of the large and nonconstant variability in these experiments and the incommensurability between different microarray technologies, there is the issue of the users having to adjust a series of parameters that significantly affect the outcome of the analyses and that do not have a biological or medical meaning. In this study, the identification of potential cancer biomarkers from microarray data is casted as a multiple criteria optimization (MCO) problem. The efficient solutions to this problem, found here through data envelopment analysis (DEA), are associated to genes that are proposed as potential cancer biomarkers. The method does not require any parameter adjustment by the user, and thus fosters repeatability. The approach also allows the analysis of different microarray experiments, microarray platforms, and cancer types simultaneously. The results include the analysis of three publicly available microarray databases related to cervix cancer. This study points to the feasibility of modeling the selection of potential cancer biomarkers from microarray data as an MCO problem and solve it using DEA. Using MCO entails a new optic to the identification of potential cancer biomarkers as it does not require the definition of a threshold value to establish significance for a particular gene and the selection of a normalization procedure to compare different experiments is no longer necessary.

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.

Gene expression and pathologic response to neoadjuvant chemotherapy in breast cancer

Pathologic complete response after neoadjuvant systemic treatment appears to be a valid surrogate for better overall survival in breast cancer patients. Currently, together with standard clinicopathologic assessment, novel molecular biomarkers are being exhaustively tested in order to look into the heterogeneity of breast cancer. The aim of our study was to examine an association between 23-gene real-time-PCR expression assay including ABCB1, ABCC1, BAX, BBC3, BCL2, CASP3, CYP2D6, ERCC1, FOXC1, GAPDH, IGF1R, IRF1, MAP2, MAPK 8, MAPK9, MKI67, MMP9, NCOA3, PARP1, PIK3CA, TGFB3, TOP2A, and YWHAZ receptor status of breast cancer core biopsies sampled before neoadjuvant chemotherapy (anthracycline and taxanes) and pathologic response. Core-needle biopsies were collected from 42 female patients with inoperable locally advanced breast cancer or resectable tumors suitable for downstaging, before any treatment. Expressions of 23 genes were determined by means of TagMan low density arrays. Analysis of variance was used to select genes with discriminatory potential between receptor subtypes. We introduced a correction for false discovery rates (presented as q values) due to multiple hypothesis testing. Statistical analysis showed that seven genes out of a 23-gene real-time-PCR expression assay differed significantly in relation to pathologic response regardless of breast cancer subtypes. Among these genes, we identified: BAX (p = 0.0146), CYP2D6 (p = 0.0063), ERCC1 (p = 0.0231), FOXC1 (p = 0.0048), IRF1 (p = 0.0022), MAP2 (p = 0.0011), and MKI67 (p = 0.0332). The assessment of core biopsy gene profiles and receptor-based subtypes, before neoadjuvant therapy seems to predict response or resistance and to define new signaling pathways to provide more powerful classifiers in breast cancer, hence the need for further research.