Gene expression and pathologic response to neoadjuvant chemotherapy in breast cancer

Characterization of BCL-X L , MCL-1, and BAX Protein Expression in Response to Neoadjuvant Chemotherapy in Breast Cancer

The use of chemotherapy has improved the overall treatment of breast cancer, which is frequently administered in the form of neoadjuvant chemotherapy (NAC). Apoptosis is an established cell stress response to NAC in preclinical models; however, there is limited understanding of its role in clinical cancer, specifically, its contribution to favorable pathologic responses in breast cancer therapy. Here, we aimed to characterize the change in protein expression of 3 apoptosis-associated biomarkers, namely, BCL-X L , MCL-1, and BAX in breast cancer in response to NAC. For this, we utilized a set of 68 matched invasive breast cancer FFPE samples that were collected before (pre) and after (post) the exposure to NAC therapy that were characterized by incomplete pathologic response. Immunohistochemistry (IHC) analysis suggested that most of the samples show a decrease in the protein expression of all 3 markers following exposure to NAC as 90%, 69%, and 76% of the matched samples exhibited a decrease in expression for BCL-X L , MCL-1, and BAX, respectively. The median H-score of BCL-X L post-NAC was 150/300 compared with 225/300 pre-NAC ( P value <0.0001). The median H-score of MCL-1 declined from 200 pre-NAC to 160 post-NAC ( P value <0.0001). The median H-score of BAX protein expression decreased from 260 pre-NAC to 190 post-NAC ( P value <0.0001). There was no statistically significant association between the expression of these markers and stage, grade, and hormone receptor profiling (luminal status). Collectively, our data indicate that the expression of apoptosis regulatory proteins changes following exposure to NAC in breast cancer tissue, developing a partial pathologic response.

Expression of the microtubule-associated protein 2 (MAP2) as a potential independent prognostic marker in prostate cancer

PURPOSE

Investigation of Microtubuli-associated Protein 2 (MAP2) expression and its clinical relevance in prostate cancer.

MATERIAL AND METHODS

MAP2 expression was immunohistochemically analysed on radical prostatectomy specimens using whole block sections (n = 107) and tissue microarrays (TMA; n = 310). The staining intensity was evaluated for carcinoma, benign tissue and prostatic intraepithelial neoplasia. Expression data were correlated with clinicopathological parameters and biochemical recurrence-free survival. Additionally, MAP2 protein expression was quantitatively analysed in the serum of histologically confirmed prostate carcinoma patients and the control group using a commercial enzyme-linked immunosorbent assay.

RESULTS

MAP2 staining was significantly stronger in neoplastic tissue than in non-neoplastic prostatic glands, both in whole block sections (p < 0.01) and in TMA sections (p < 0.05). TMA data revealed significantly stronger MAP2 staining in high-grade tumors. Survival analysis showed a significant correlation between strong MAP2 staining in carcinoma and shortened biochemical recurrence-free survival after prostatectomy (p < 0.001). Multivariate Cox regression analysis confirmed MAP2 as an independent predictor for an unfavourable course. Mean MAP2 serum levels for non-PCA vs. PCA patients differed significantly (non-PCA = 164.7 pg/ml vs. PCA = 242.5 pg/ml, p < 0.001).

CONCLUSION

The present data support MAP2 as a novel biomarker in PCA specimens. MAP2 is correlated with tumor grade and MAP2 high-expressing PCA is associated with an increased risk of biochemical recurrence after radical prostatectomy. Future studies are necessary to evaluate MAP2 as a valuable immunohistochemical biomarker in preoperative PCA diagnostic procedures, in particular with regard to treatment modalities.

Different impacts of TP53 mutations on cell cycle-related gene expression among cancer types

Functional properties caused by TP53 mutations are involved in cancer development and progression. Although most of the mutations lose normal p53 functions, some of them, gain-of-function (GOF) mutations, exhibiting novel oncogenic functions. No reports have analyzed the impact of TP53 mutations on the gene expression profile of the p53 signaling pathway across cancer types. This study is a cross-cancer type analysis of the effects of TP53 mutations on gene expression. A hierarchical cluster analysis of the expression profile of the p53 signaling pathway classified 21 cancer types into two clusters (A1 and A2). Changes in the expression of cell cycle-related genes and MKI67 by TP53 mutations were greater in cluster A1 than in cluster A2. There was no distinct difference in the effects between GOF and non-GOF mutations on the gene expression profile of the p53 signaling pathway.

Microtubule-associated protein 2 knockdown sensitizes glioma cells to vincristine treatment

Gliomas are the most common and lethal tumor of the central nervous system (CNS). At present, standard treatment involves chemotherapy and radiotherapy after surgery, but the prognosis for most gliomas remains poor due to tumor heterogeneity and drug resistance. Microtubule-associated protein 2 (MAP2), a microtubule-stabilizing protein, plays a critical role in many cellular processes and may correlate with the proliferation, apoptosis, and drug sensitivity of tumor cells, especially their sensitivity to microtubule-targeting drugs (MTDs). In this study, we investigated the role of MAP2 in gliomas and its relationship to the chemosensitivity of vincristine (VCR), an MTD commonly used in glioma chemotherapy. We downregulated MAP2 expression in glioma cells using RNA interference, observed the resultant changes in the biological characteristics of the cells, and tested their drug sensitivity to VCR by MTT assay. The results show downregulation of MAP2 in glioma cells significantly inhibited cell viability and migration, induced apoptosis, and increased sensitivity to VCR in vitro. Our findings suggest that MAP2 may be a useful molecular marker in MTD chemotherapy and a potential therapeutic target in gliomas.

Proteomic analysis of gemcitabine-resistant pancreatic cancer cells reveals that microtubule-associated protein 2 upregulation associates with taxane treatment

Background:

Chemoresistance hampers the treatment of patients suffering from pancreatic ductal adenocarcinoma (PDAC). Here we aimed to evaluate the (phospho)proteome of gemcitabine-sensitive and gemcitabine-resistant PDAC cells to identify novel therapeutic targets and predictive biomarkers.

Methods:

The oncogenic capabilities of gemcitabine-sensitive and resistant PDAC cells were evaluated in vitro and in vivo. Cultured cells were analyzed by label-free proteomics. Differential proteins and phosphopeptides were evaluated by gene ontology and for their predictive or prognostic biomarker potential with immunohistochemistry of tissue microarrays.

Results:

Gemcitabine-resistant cells had increased potential to induce xenograft tumours (p value < 0.001). Differential analyses showed that proteins associated with gemcitabine resistance are correlated with microtubule regulation. Indeed, gemcitabine-resistant cells displayed an increased sensitivity for paclitaxel in vitro (p < 0.001) and nab-paclitaxel had a strong anti-tumour efficacy in vivo. Microtubule-associated protein 2 (MAP2) was found to be highly upregulated (p = 0.002, fold change = 10) and phosphorylated in these resistant cells. Expression of MAP2 was correlated with a poorer overall survival in patients treated with gemcitabine in the palliative (p = 0.037) and adjuvant setting (p = 0.014).

Conclusions:

These data show an explanation as to why the combination of gemcitabine with nab-paclitaxel is effective in PDAC patients. The identified gemcitabine-resistance marker, MAP2, emerged as a novel prognostic marker in PDAC patients treated with gemcitabine and warrants further clinical investigation.

Soy Foods Might Weaken the Sensitivity of Tamoxifen in Premenopausal Patients With Lumina A Subtype of Breast Cancer

BACKGROUND

Based on estrogen active substances, many women consume soy foods in the belief that it could prevent breast cancer (BC). Women with different molecular subtypes would be likely to have diverse reactions to soy foods, especially those with the estrogen-receptor-positive (ER⁺) subtype. The aim of the current study is to identify the differentially expressed genes (DEGs) on soy foods in premenopausal patients with Lumina A subtype of BC (LABC) after soy food treatment, and to further investigate the critical molecule change.

MATERIALS AND METHODS

GSE58792 retrieved from Gene Expression Omnibus was analyzed to obtain DEGs using GEO2R. Gene Ontology and pathway enrichment analysis were performed using FunRich and GeneMINIA. Overall survival of critical genes was performed by the Kaplan-Meier plotter online tool.

RESULTS

A total of 108 DEGs were obtained from the dataset, among which 35 were up-regulated and 73 down-regulated. Soy foods significantly reduced the expression of TFF3, TFF1, GATA3, and ESR1, which were related to the activity of the ER-related pathway and the sensitivity of tamoxifen. Furthermore, the lower expressions of TOX3, FSIP1, ESR1, and CLGN were related to prolonged survival time of patients with BC. The most significant signaling pathways were epithelial-to-mesenchymal transition in up-regulated DEGs, mesenchymal-to-epithelial transition, and mammary gland alveolus development in down-regulated DEGs, which were all related to the development and prognosis of BC.

CONCLUSIONS

Soy foods could dramatically alter the ER-related gene profile in LABC. Particularly, down-regulated DEGs of TFF3, TFF1, GATA3, and ESR1 might weaken the sensitivity of tamoxifen and increase the efficacy of neoadjuvant chemotherapy in premenopausal patients with LABC.

Specific breast cancer prognosis-subtype distinctions based on DNA methylation patterns

Tumour heterogeneity is an obstacle to effective breast cancer diagnosis and therapy. DNA methylation is an important regulator of gene expression, thus characterizing tumour heterogeneity by epigenetic features can be clinically informative. In this study, we explored specific prognosis-subtypes based on DNA methylation status using 669 breast cancers from the TCGA database. Nine subgroups were distinguished by consensus clustering using 3869 CpGs that significantly influenced survival. The specific DNA methylation patterns were reflected by different races, ages, tumour stages, receptor status, histological types, metastasis status and prognosis. Compared with the PAM50 subtypes, which use gene expression clustering, DNA methylation subtypes were more elaborate and classified the Basal-like subtype into two different prognosis-subgroups. Additionally, 1252 CpGs (corresponding to 888 genes) were identified as specific hyper/hypomethylation sites for each specific subgroup. Finally, a prognosis model based on Bayesian network classification was constructed and used to classify the test set into DNA methylation subgroups, which corresponded to the classification results of the train set. These specific classifications by DNA methylation can explain the heterogeneity of previous molecular subgroups in breast cancer and will help in the development of personalized treatments for the new specific subtypes.

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.

Identification of stromal ColXα1 and tumor-infiltrating lymphocytes as putative predictive markers of neoadjuvant therapy in estrogen receptor-positive/HER2-positive breast cancer

Background

The influence of the tumor microenvironment and tumor-stromal interactions on the heterogeneity of response within breast cancer subtypes have just begun to be explored. This study focuses on patients with estrogen receptor-positive/human epidermal growth factor receptor 2-positive (ER+/HER2+) breast cancer receiving neoadjuvant chemotherapy and HER2-targeted therapy (NAC+H), and was designed to identify novel predictive biomarkers by combining gene expression analysis and immunohistochemistry with pathologic response.

Methods

We performed gene expression profiling on pre-NAC+H tumor samples from responding (no or minimal residual disease at surgery) and non-responding patients. Gene set enrichment analysis identified potentially relevant pathways, and immunohistochemical staining of pre-treatment biopsies was used to measure protein levels of those pathways, which were correlated with pathologic response in both univariate and multivariate analysis.

Results

Increased expression of genes encoding for stromal collagens, including Col10A1, and reduced expression of immune-associated genes, reflecting lower levels of total tumor-infiltrating lymphocytes (TILs), were strongly associated with poor pathologic response. Lower TILs in tumor biopsies correlated with reduced likelihood of achieving an optimal pathologic response, but increased expression of the Col10A1 gene product, colXα1, had greater predictive value than stromal abundance for poor response (OR = 18.9, p = 0.003), and the combination of increased colXα1 expression and low TILs was significantly associated with poor response in multivariate analysis. ROC analysis suggests strong specificity and sensitivity for this combination in predicting treatment response.

Conclusions

Increased expression of stromal colXα1 and low TILs correlate with poor pathologic response in ER+/HER2+ breast tumors. Further studies are needed to confirm their predictive value and impact on long-term outcomes, and to determine whether this collagen exerts a protective effect on the cancer cells or simply reflects other factors within the tumor microenvironment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2302-5) contains supplementary material, which is available to authorized users.

Predictive Value of Ercc1 and Xpd Polymorphisms for Clinical Outcomes of Patients Receiving Neoadjuvant Therapy: A Prisma-Compliant Meta-Analysis

Excision repair cross complementing 1 (ERCC1) and xeroderma pigmentosum group D (XPD) play important roles in the nucleotide excision repair (NER) pathway. The correlation between ERCC1 polymorphisms (rs11615 and rs3212986) and XPD polymorphisms (rs13181 and rs1799793) with the response rate and overall survival of cancer patients who accept neoadjuvant therapy has been extensively investigated. However, the results are inconclusive. In this study, we performed a meta-analysis to determine the strength of this correlation. A comprehensive literature search was conducted in Medline, PubMed, and Embase up to February 2015. A review of all titles and abstracts was performed by 2 of the authors to screen the articles based on the eligibility criteria. Clinical trials, observational studies, and epidemiological studies describing ERCC polymorphisms and neoadjuvant treatment were considered for review. The response rate was analyzed using pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs). Overall survival was assessed using the hazard ratio (HR) with corresponding 95% confidence intervals. In the present meta-analysis, we demonstrated that the ERCC1 rs3212986 polymorphism was significantly correlated with the response rate of esophageal cancer patients to neoadjuvant therapy (OR =  .49, 95% CI = 0.31-0.76, heterogeneity P = 0.480). Furthermore, a considerable correlation was observed between ERCC1 rs11615 and the response rate of esophageal cancer patients to neoadjuvant therapy (OR = 0.228, 95% CI = 0.125-0.418, heterogeneity P = 0.291). No correlation was observed in the meta-analysis of overall survival. The individual studies included in our study differed in their patient selection and therapeutic protocols, which might lead to some bias in the results. These findings indicate that the ERCC1 rs11615 and ERCC1 rs312986 polymorphisms may be candidate pharmacogenomic factors capable of predicting the response rate of esophageal cancer patients who accept neoadjuvant therapy. Further studies are warranted.

Serial expression analysis of breast tumors during neoadjuvant chemotherapy reveals changes in cell cycle and immune pathways associated with recurrence and response

INTRODUCTION

The molecular biology involving neoadjuvant chemotherapy (NAC) response is poorly understood. To elucidate the impact of NAC on the breast cancer transcriptome and its association with clinical outcome, we analyzed gene expression data derived from serial tumor samples of patients with breast cancer who received NAC in the I-SPY 1 TRIAL.

METHODS

Expression data were collected before treatment (T1), 24-96 hours after initiation of chemotherapy (T2) and at surgery (TS). Expression levels between T1 and T2 (T1 vs. T2; n = 36) and between T1 and TS (T1 vs. TS; n = 39) were compared. Subtype was assigned using the PAM50 gene signature. Differences in early gene expression changes (T2 - T1) between responders and nonresponders, as defined by residual cancer burden, were evaluated. Cox proportional hazards modeling was used to identify genes in residual tumors associated with recurrence-free survival (RFS). Pathway analysis was performed with Ingenuity software.

RESULTS

When we compared expression profiles at T1 vs. T2 and at T1 vs. TS, we detected significantly altered expression of 150 and 59 transcripts, respectively. We observed notable downregulation of proliferation and immune-related genes at T2. Lower concordance in subtype assignment was observed between T1 and TS (62 %) than between T1 and T2 (75 %). Analysis of early gene expression changes (T2 - T1) revealed that decreased expression of cell cycle inhibitors was associated with poor response. Increased interferon signaling (TS - T1) and high expression of cell proliferation genes in residual tumors (TS) were associated with reduced RFS.

CONCLUSIONS

Serial gene expression analysis revealed candidate immune and proliferation pathways associated with response and recurrence. Larger studies incorporating the approach described here are warranted to identify predictive and prognostic biomarkers in the NAC setting for specific targeted therapies.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00033397 . Registered 9 Apr 2002.

Interferon regulatory factor-1 signaling regulates the switch between autophagy and apoptosis to determine breast cancer cell fate

Interferon regulatory factor-1 (IRF1) is a tumor suppressor that regulates cell fate in several cell types. Here, we report an inverse correlation in expression of nuclear IRF1 and the autophagy regulator ATG7 in human breast cancer cells that directly affects their cell fate. In mice harboring mutant Atg7, nuclear IRF1 was increased in mammary tumors, spleen, and kidney. Mechanistic investigations identified ATG7 and the cell death modulator beclin-1 (BECN1) as negative regulators of IRF1. Silencing ATG7 or BECN1 caused estrogen receptor-α to exit the nucleus at the time when IRF1 nuclear localization occurred. Conversely, silencing IRF1 promoted autophagy by increasing BECN1 and blunting IGF1 receptor and mTOR survival signaling. Loss of IRF1 promoted resistance to antiestrogens, whereas combined silencing of ATG7 and IRF1 restored sensitivity to these agents. Using a mathematical model to prompt signaling hypotheses, we developed evidence that ATG7 silencing could resensitize IRF1-attenuated cells to apoptosis through mechanisms that involve other estrogen-regulated genes. Overall, our work shows how inhibiting the autophagy proteins ATG7 and BECN1 can regulate IRF1-dependent and -independent signaling pathways in ways that engender a new therapeutic strategy to attack breast cancer.