HIPK2 cooperates with KRAS signaling and associates with colorectal cancer progression

HIPK2 is an evolutionary conserved kinase that has gained attention as a fine tuner of multiple signaling pathways, among which those commonly altered in colorectal cancer (CRC). The aim of this study was to evaluate the relationship of HIPK2 expression with progression markers and mutational pattern and gain insights into the contribution of HIPK2 activity in CRC. We evaluated a retrospective cohort of CRC samples by immunohistochemistry for HIPK2 expression and by NGS for the detection of mutations of cancer associated genes. We show that the percentage of HIPK2 positive cells increases with tumor progression, significantly correlates with TNM staging and associates with a worse outcome. In addition, we observed that high HIPK2 expression significantly associates with KRAS mutations but not with other cancer related genes. Functional characterization of the link between HIPK2 and KRAS show that activation of the RAS pathway either due to KRAS mutation or via upstream receptor stimulation, increases HIPK2 expression at the protein level. Of note, HIPK2 physically participates in the active RAS complex while HIPK2 depletion impairs ERK phosphorylation and the growth of tumors derived from KRAS mutated CRC cells. Overall, this study identifies HIPK2 as a prognostic biomarker candidate in CRC patients and underscores a previously unknown functional link between HIPK2 and the KRAS signaling pathway. Implications: Our data indicate HIPK2 as a new player in the complex picture of the KRAS signaling network, providing rationales for future clinical studies and new treatment strategies for KRAS mutated CRC.

HIPK2 is a potential predictive marker of a favorable response for adjuvant chemotherapy in stage II colorectal cancer

Colorectal cancer (CRC) is the third most frequently diagnosed type of cancer worldwide. Stage II CRC accounts for ~25% all CRC cases and their management after surgical resection remains a clinical dilemma due to the lack of reliable criteria for identifying patients who may benefit from adjuvant chemotherapy. Homeodomain‑interacting protein kinase 2 (HIPK2), a multifunctional kinase involved in numerous signaling pathways, serves several key roles in cell response to different types of stresses, including chemotherapy‑induced genotoxic damage. In the present study, immunohistochemistry was performed for HIPK2 on a tissue microarray of primary human tumor samples from 84 patients with stage II CRC, treated (30 patients) or not treated (54 patients) with adjuvant chemotherapy, and sequenced for the TP53 gene, a key HIPK2 target in genotoxic damage response. It was observed that, regardless of the TP53 gene status, a high percentage of HIPK2+ cells was associated with therapeutic vulnerability in stage II CRC, suggesting a contribution of HIPK2 to drug‑response in vivo. For the in vitro characterization, HIPK2 was depleted in human CRC cells by CRISPR/Cas9 or RNA interference. HIPK2‑proficient and HIPK2‑defective cells were evaluated for their response to 5‑fluorouracil (5‑FU) and oxaliplatin (OXA). The results revealed that HIPK2 depletion induced resistance to 5‑FU and OXA, and that this resistance was not overcome by brusatol, an inhibitor of the antioxidant response regulator nuclear factor erythroid 2‑related factor 2 (NRF2), which is frequently overexpressed in CRC. By contrast, cell sensitivity to 5‑FU and OXA was further induced by brusatol supplementation in HIPK2‑proficient cells, further supporting the contribution of HIPK2 in chemotherapy response. Overall, the present results suggested that HIPK2 may be a potential predictive marker for adjuvant‑treated stage II CRC and for prospective therapy with NRF2 modulators.

TRF2 and VEGF-A: an unknown relationship with prognostic impact on survival of colorectal cancer patients

BACKGROUND

Colorectal cancer is one of most common tumors in developed countries and, despite improvements in treatment and diagnosis, mortality rate of patients remains high, evidencing the urgent need of novel biomarkers to properly identify colorectal cancer high-risk patients that would benefit of specific treatments. Recent works have demonstrated that the telomeric protein TRF2 is over-expressed in colorectal cancer and it promotes tumor formation and progression through extra-telomeric functions. Moreover, we and other groups evidenced, both in vitro on established cell lines and in vivo on tumor bearing mice, that TRF2 regulates the vascularization mediated by VEGF-A. In the present paper, our data evidence a tight correlation between TRF2 and VEGF-A with prognostic relevance in colorectal cancer patients.

METHODS

For this study we sampled 185 colorectal cancer patients surgically treated and diagnosed at the Regina Elena National Cancer Institute of Rome and investigated the association between the survival outcome and the levels of VEGF-A and TRF2.

RESULTS

Tissue microarray immunohistochemical analyses revealed that TRF2 positively correlates with VEGF-A expression in our cohort of patients. Moreover, analysis of patients' survival, confirmed in a larger dataset of patients from TCGA, demonstrated that co-expression of TRF2 and VEGF-A correlate with a poor clinical outcome in stage I-III colorectal cancer patients, regardless the mutational state of driver oncogenes.

CONCLUSIONS

Our results permitted to identify the positive correlation between high levels of TRF2 and VEGF-A as a novel prognostic biomarker for identifying the subset of high-risk colorectal cancer patients that could benefit of specific therapeutic regimens.

p53 and BLC2 Immunohistochemical Expression Across Molecular Subtypes in 1099 Early Breast Cancer Patients With Long-Term Follow-up: An Observational Study

INTRODUCTION

p53 and antiapoptotic B-cell leukemia/lymphoma 2 (BLC2) have been proposed as prognostic markers for early breast cancer (BC), although their relationship with conventional parameters and patient prognosis, as well as their distribution within the molecular BC subtypes remains uncertain.

PATIENTS AND METHODS

In this observational study, we analyzed the immunohistochemical expression of p53 and BLC2 in 1099 early BC patients surgically treated between 2000 and 2006 and followed for at least 5 years, also considering their association with pathologic factors and molecular subtypes, as well as their influence on disease-free survival.

RESULTS

p53 and BLC2 are distributed differently across molecular subtypes (P < .0001); in particular, p53 positivity and BLC2 negativity seems to be associated with more aggressive conventional tumor phenotypes. Moreover, BLC2 negativity seems to be a significant discriminating factor for disease-free survival (P = .003) according to Kaplan-Meier analysis, while p53 seems to have no discriminating effect. Among patients with discordant p53/BLC2 phenotype, the combination p53⁺BLC2^- seems to be associated with the worst outcomes (P = .007) and significantly influenced the clinical course of node-negative patients treated only with hormone therapy (P = .004).

CONCLUSION

These two biomarkers, in addition to conventional pathologic factors and molecular subtype, could help define the risk and outcome of BC.

TRF2 positively regulates SULF2 expression increasing VEGF-A release and activity in tumor microenvironment

The telomeric protein TRF2 is overexpressed in several human malignancies and contributes to tumorigenesis even though the molecular mechanism is not completely understood. By using a high-throughput approach based on the multiplexed Luminex X-MAP technology, we demonstrated that TRF2 dramatically affects VEGF-A level in the secretome of cancer cells, promoting endothelial cell-differentiation and angiogenesis. The pro-angiogenic effect of TRF2 is independent from its role in telomere capping. Instead, TRF2 binding to a distal regulatory element promotes the expression of SULF2, an endoglucosamine-6-sulfatase that impairs the VEGF-A association to the plasma membrane by inducing post-synthetic modification of heparan sulfate proteoglycans (HSPGs). Finally, we addressed the clinical relevance of our findings showing that TRF2/SULF2 expression is a worse prognostic biomarker in colorectal cancer (CRC) patients.

PLC-gamma-1 phosphorylation status is prognostic of metastatic risk in patients with early-stage Luminal-A and -B breast cancer subtypes

Background

Phospholipase Cγ1 (PLCγ1) is highly expressed in human tumours. Our previous studies reported that both stable and inducible PLCγ1 down-regulation can inhibit formation of breast-cancer-derived experimental lung metastasis. Further, high expression of PLCγ1 and its constitutively activated forms (i.e., PLCγ1-pY1253, PLCγ1-pY783) is associated with worse clinical outcome in terms of incidence of distant metastases, but not of local relapse in T1-T2, N0 breast cancer patients.

Methods

In the present retrospective study, we analysed the prognostic role of PLCγ1 in early breast cancer patients stratified according to the St. Gallen criteria and to their menopausal status. PLCγ1-pY1253 and PLCγ1-pY783 protein expression levels were determined by immunohistochemistry on tissue microarrays, and were correlated with patients’ clinical data, using univariate and multivariate statistical analyses.

Results

In our series, the prognostic value of PLCγ1 overexpression was restricted to Luminal type tumours. From multivariate analyses, pY1253-PLCγ1^High was an independent prognostic factor only in postmenopausal patients with Luminal-B tumours (hazard ratio [HR], 2.4; 95% confidence interval [CI], 1.1–5.3; P = 0.034). Conversely, PLCγ1-pY783^High was a remarkably strong risk factor (HR, 20.1; 95% CI, 2.2–178.4; P = 0.003) for pre/perimenopausal patients with Luminal-A tumours.

Conclusions

PLCγ1 overexpression is a strong predictive surrogate marker of development of metastases in early Luminal-A and -B breast cancer patients, being able to discriminate patients with high and low risk of metastases. Therefore, targeting the PLCγ1 pathway can be considered of potential benefit for prevention of metastatic disease.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5949-x) contains supplementary material, which is available to authorized users.

C-Myc Deregulation is Involved in Melphalan Resistance of Multiple Myeloma: Role of PDGF-BB

Oncogenes are important regulators of cancer growth and progression and their action may be modulated by proteins of the growth factor family, such as angiogenic cytokines, known to be strongly involved in neoplastic evolution. Reciprocal interactions between oncogenes and angiogenic modulators may represent, in haematological neoplasms, including multiple myeloma (MM), a possible mechanism of drug resistance. The aim of this work is to investigate in vitro and in vivo whether or not c-myc deregulation is involved in the melphalan resistance elicited by myeloma patients and consequently to clarify the role of the angiogenic factor PDGF-BB in modulating c-myc protein expression. Fifty-one MM patients on chemotherapy with melphalan were analyzed for structural alterations of the c-myc gene, c-Myc protein expression, as well as for serum PDGF-BB release. For the in vitro study, two M14-derived established cell clones, differing for the c-Myc protein expression (c-Myc low -expressing or constitutively expressing clones) were used. Our results show that PDGF-BB is able to up-regulate Myc expression and reduce melphalan sensitivity of tumor cell clones, constitutively expressing c-myc gene product. In addition, down-regulation of c-Myc protein induces the expression of PDGF-β receptor molecules and reduces PDGF-BB release. In agreement with these results, in vivo data show that melphalan-resistant MM patients present overexpressed c-Myc protein and higher serum PDGF-β receptor levels compared to minor responding patients.

Stanniocalcin 2 expression is associated with a favourable outcome in male breast cancer

Breast cancer can occur in either gender; however, it is rare in men, accounting for <1% of diagnosed cases. In a previous transcriptomic screen of male breast cancer (MBC) and female breast cancer (FBC) occurrences, we observed that Stanniocalcin 2 (STC2) was overexpressed in the former. The aim of this study was to confirm the expression of STC2 in MBC and to investigate whether this had an impact on patient prognosis. Following an earlier transcriptomic screen, STC2 gene expression was confirmed by RT‐qPCR in matched MBC and FBC samples as well as in tumour‐associated fibroblasts derived from each gender. Subsequently, STC2 protein expression was examined immunohistochemically in tissue microarrays containing 477 MBC cases. Cumulative survival probabilities were calculated using the Kaplan–Meier method and multivariate survival analysis was performed using the Cox hazard model. Gender‐specific STC2 gene expression showed a 5.6‐fold upregulation of STC2 transcripts in MBC, also supported by data deposited in Oncomine™. STC2 protein expression was a positive prognostic factor for disease‐free survival (DFS; Log‐rank; total p = 0.035, HR = 0.49; tumour cells p = 0.017, HR = 0.44; stroma p = 0.030, HR = 0.48) but had no significant impact on overall survival (Log‐rank; total p = 0.23, HR = 0.71; tumour cells p = 0.069, HR = 0.59; stroma p = 0.650, HR = 0.87). Importantly, multivariate analysis adjusted for patient age at diagnosis, node staging, tumour size, ER, and PR status revealed that total STC2 expression as well as expression in tumour cells was an independent prognostic factor for DFS (Cox regression; p = 0.018, HR = 0.983; p = 0.015, HR = 0.984, respectively). In conclusion, STC2 expression is abundant in MBC where it is an independent prognostic factor for DFS.

Abstract 5224: hMENA isoforms impact NSCLC patient outcome through fibronectin/β1 integrin axis

The splicing of the actin regulator hMENA generates different isoforms and we have demonstrated that the two alternatively expressed isoforms, hMENA11a and hMENAΔv6, have opposite functions in cell invasiveness. This general mechanism is of great clinical relevance in early NSCLC patients, where the pattern of hMENA isoform expression is a powerful prognostic factor. However the mechanism of action of the two isoforms have remained unclear. Herein, we evaluated whether hMENA and its isoforms influence β1 integrin expression and signaling considering the role of this integrin in cancer cell invasiveness and tumor progression. We performed hMENA silencing by siRNA and shRNA, to evaluate by QRT-PCR and biochemical approaches the expression of β1 integrin; by immunofluorescence the MRTF1 localization, by in vivo assay G-Actin/F-Actin ratio and by luciferase reporter assay the SRF activity. β1 integrin activation and signaling was evaluated by flow cytometry using an antibody specific for the β1 active conformation and by biochemical analysis of the phosphorylation of FAK, SRC and Paxillin. The secretoma of hMENA11a transfected cancer cell lines was analyzed by LC-MS/MS. Immunohistochemical analysis was performed using pan-hMENA, hMENA11a, and fibronectin antibodies in primary cancer tissues from node negative NSCLC patients. The Chi-Square or Fisher Exact tests were used to estimate associations among categorical variables and disease-free survival was calculated by the Kaplan-Meier product limit method. We show that the depletion of all hMENA isoforms inhibits the Serum Response Factor (SRF) activity, and the expression of its target gene β1 Integrin, by affecting G-Actin/F-Actin ratio, critical for the nuclear localization of the SRF co-factor myocardin related transcription factor 1 (MRTF1). Furthermore, we provide new insights into the mechanisms involved in the opposite functions of hMENA11a and hMENAΔv6 in cell invasiveness and we identify a new role of these isoforms in the β1 integrin-ECM signalling axis. Indeed, hMENAΔv6-drives cancer cell invasion by increasing β1 integrin activation and signalling, which is reduced by the anti-invasive hMENA11a isoform. Moreover, exogenous expression of hMENA11a in hMENAΔv6 positive cancer cells dramatically reduces secretion of extracellular matrix (ECM) components, including β1 integrin ligands and metalloproteinases. On the other hand overexpression of the pro-invasive hMENAΔv6 increases fibronectin production. In primary tumors high hMENA11a correlates with low stromal fibronectin and favorable clinical outcome of early node-negative non-small cell lung cancer patients. This newly discovered signature, which pays attention to the alternative splicing of hMENA and ECM components such as fibronectin in the stroma, might help fill in the gap in the still controversial clinical management of early node-negative NSCLC patients.

Citation Format: Francesca Di Modugno, Sheila Spada, Belinda Palermo, Paolo Visca, Pierluigi Iapicca, Anna Di Carlo, Barbara Antoniani, Isabella Sperduti, Anna Di Benedetto, Irene Terrenato, Marcella Mottolese, Francesco Gandolfi, Francesco Facciolo, Emily Chen, Martin A. Schwartz, Angela Santoni, Mina J. Bissell, Paola Nisticò. hMENA isoforms impact NSCLC patient outcome through fibronectin/β1 integrin axis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5224.

Expression of ID4 protein in breast cancer cells induces reprogramming of tumour-associated macrophages

Background

As crucial regulators of the immune response against pathogens, macrophages have been extensively shown also to be important players in several diseases, including cancer. Specifically, breast cancer macrophages tightly control the angiogenic switch and progression to malignancy. ID4, a member of the ID (inhibitors of differentiation) family of proteins, is associated with a stem-like phenotype and poor prognosis in basal-like breast cancer. Moreover, ID4 favours angiogenesis by enhancing the expression of pro-angiogenic cytokines interleukin-8, CXCL1 and vascular endothelial growth factor. In the present study, we investigated whether ID4 protein exerts its pro-angiogenic function while also modulating the activity of tumour-associated macrophages in breast cancer.

Methods

We performed IHC analysis of ID4 protein and macrophage marker CD68 in a triple-negative breast cancer series. Next, we used cell migration assays to evaluate the effect of ID4 expression modulation in breast cancer cells on the motility of co-cultured macrophages. The analysis of breast cancer gene expression data repositories allowed us to evaluate the ability of ID4 to predict survival in subsets of tumours showing high or low macrophage infiltration. By culturing macrophages in conditioned media obtained from breast cancer cells in which ID4 expression was modulated by overexpression or depletion, we identified changes in the expression of ID4-dependent angiogenesis-related transcripts and microRNAs (miRNAs, miRs) in macrophages by RT-qPCR.

Results

We determined that ID4 and macrophage marker CD68 protein expression were significantly associated in a series of triple-negative breast tumours. Interestingly, ID4 messenger RNA (mRNA) levels robustly predicted survival, specifically in the subset of tumours showing high macrophage infiltration. In vitro and in vivo migration assays demonstrated that expression of ID4 in breast cancer cells stimulates macrophage motility. At the molecular level, ID4 protein expression in breast cancer cells controls, through paracrine signalling, the activation of an angiogenic programme in macrophages. This programme includes both the increase of angiogenesis-related mRNAs and the decrease of members of the anti-angiogenic miR-15b/107 group. Intriguingly, these miRNAs control the expression of the cytokine granulin, whose enhanced expression in macrophages confers increased angiogenic potential.

Conclusions

These results uncover a key role for ID4 in dictating the behaviour of tumour-associated macrophages in breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0990-2) contains supplementary material, which is available to authorized users.

CHK1-targeted therapy to deplete DNA replication-stressed, p53-deficient, hyperdiploid colorectal cancer stem cells

OBJECTIVE

Cancer stem cells (CSCs) are responsible for tumour formation and spreading, and their targeting is required for tumour eradication. There are limited therapeutic options for advanced colorectal cancer (CRC), particularly for tumours carrying RAS-activating mutations. The aim of this study was to identify novel CSC-targeting strategies.

DESIGN

To discover potential therapeutics to be clinically investigated as single agent, we performed a screening with a panel of FDA-approved or investigational drugs on primary CRC cells enriched for CSCs (CRC-SCs) isolated from 27 patients. Candidate predictive biomarkers of efficacy were identified by integrating genomic, reverse-phase protein microarray (RPPA) and cytogenetic analyses, and validated by immunostainings. DNA replication stress (RS) was increased by employing DNA replication-perturbing or polyploidising agents.

RESULTS

The drug-library screening led to the identification of LY2606368 as a potent anti-CSC agent acting in vitro and in vivo in tumour cells from a considerable number of patients (∼36%). By inhibiting checkpoint kinase (CHK)1, LY2606368 affected DNA replication in most CRC-SCs, including RAS-mutated ones, forcing them into premature, lethal mitoses. Parallel genomic, RPPA and cytogenetic analyses indicated that CRC-SCs sensitive to LY2606368 displayed signs of ongoing RS response, including the phosphorylation of RPA32 and ataxia telangiectasia mutated serine/threonine kinase (ATM). This was associated with mutation(s) in TP53 and hyperdiploidy, and made these CRC-SCs exquisitely dependent on CHK1 function. Accordingly, experimental increase of RS sensitised resistant CRC-SCs to LY2606368.

CONCLUSIONS

LY2606368 selectively eliminates replication-stressed, p53-deficient and hyperdiploid CRC-SCs independently of RAS mutational status. These results provide a strong rationale for biomarker-driven clinical trials with LY2606368 in patients with CRC.

Expression of the Hippo transducer TAZ in association with WNT pathway mutations impacts survival outcomes in advanced gastric cancer patients treated with first-line chemotherapy

Background

An extensive crosstalk co-regulates the Hippo and Wnt pathway. Preclinical studies revealed that the Hippo transducers YAP/TAZ mediate a number of oncogenic functions in gastric cancer (GC). Moreover, comprehensive characterization of GC demonstrated that the Wnt pathway is targeted by oncogenic mutations. On this ground, we hypothesized that YAP/TAZ- and Wnt-related biomarkers may predict clinical outcomes in GC patients treated with chemotherapy.

Methods

In the present study, we included 86 patients with advanced GC treated with first-line chemotherapy in prospective phase II trials or in routine clinical practice. Tissue samples were immunostained to evaluate the expression of YAP/TAZ. Mutational status of key Wnt pathway genes (CTNNB1, APC and FBXW7) was assessed by targeted DNA next-generation sequencing (NGS). Survival curves were estimated and compared by the Kaplan–Meier product-limit method and the log-rank test, respectively. Variables potentially affecting progression-free survival (PFS) were verified in univariate Cox proportional hazard models. The final multivariate Cox models were obtained with variables testing significant at the univariate analysis, and by adjusting for all plausible predictors of the outcome of interest (PFS).

Results

We observed a significant association between TAZ expression and Wnt mutations (Chi-squared p = 0.008). Combined TAZ expression and Wnt mutations (TAZ^pos/WNT^mut) was more frequently observed in patients with the shortest progression-free survival (negative outliers) (Fisher p = 0.021). Uni-and multivariate Cox regression analyses revealed that patients whose tumors harbored the TAZ^pos/WNT^mut signature had an increased risk of disease progression (univariate Cox: HR 2.27, 95% CI 1.27–4.05, p = 0.006; multivariate Cox: HR 2.73, 95% CI 1.41–5.29, p = 0.003). Finally, the TAZ^pos/WNT^mut signature negatively impacted overall survival.

Conclusions

Collectively, our findings indicate that the oncogenic YAP/TAZ–Wnt crosstalk may be active in GC, conferring chemoresistant traits that translate into adverse survival outcomes.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1385-y) contains supplementary material, which is available to authorized users.

Interobserver Reproducibility of Immunohistochemical Her-2/Neu Assessment in Human Breast Cancer: An Update from INQAT round III

The clinical interest in HER-2/neu is related to trastuzumab, a drug used to treat patients with invasive breast carcinoma overexpressing the HER-2/neu protein. It is very important to correctly identify those patients who may benefit from trastuzumab by accurate assessment of the HER-2/neu status. Of the various methods available, the Dako Herceptest for immunohistochemical assay is considered the most reliable to reach this goal. The aim of this study was to investigate within a group of Italian laboratories the reproducibility of the results of HER-2/neu assessment by means of the Dako scoring system on slides stained with the Herceptest kit. This study was also conceived as the continuation of one of our previous studies, which was similar in its aims but different in the classification criteria adopted. Our results show that, whereas the intra-observer reproducibility was generally satisfactory, the interobserver reproducibility was not. Moreover, our findings confirm that the two extreme classes (0 and 3+) are more easy to identify than the other two and that the Herceptest does not allow to discriminate optimally between scoring classes 2+ and 3+. These findings are relevant in clinical practice where the treatment choice is based on categories defined by this assay, suggesting the need of adopting educational programs and/or new reference materials to improve the assay performance.

The Hippo transducers TAZ/YAP and their target CTGF in male breast cancer

Male breast cancer (MBC) is a rare disease and its biology is poorly understood. Deregulated Hippo pathway promotes oncogenic functions in female breast cancer. We herein investigated the expression of the Hippo transducers TAZ/YAP and their target CTGF in MBC. Tissue microarrays containing samples from 255 MBC patients were immunostained for TAZ, YAP and CTGF. One hundred and twenty-nine patients were considered eligible. The Pearson's Chi-squared test of independence was used to test the association between categorical variables. The correlation between TAZ, YAP and CTGF was assessed with the Pearson's correlation coefficient. The Kaplan-Meier method and the log-rank test were used for estimating and comparing survival curves. Cox proportional regression models were built to identify variables impacting overall survival. Statistical tests were two-sided. Tumors were considered to harbor active TAZ/YAP-driven gene transcription when they co-expressed TAZ, or YAP, and CTGF. Patients whose tumors had the TAZ/CTGF and YAP/CTGF phenotypes experienced shorter overall survival compared with their negative counterparts (log rank p = 0.036 for both). TAZ/CTGF and YAP/CTGF tumors were associated with decreased survival in patients with invasive ductal carcinomas, G3 tumors, hormone receptor-positive tumors, and tumors with elevated Ki-67. Multivariate analyses confirmed that the TAZ/CTGF and YAP/CTGF phenotypes are independent predictors of survival (HR 2.03, 95% CI: 1.06-3.90, p = 0.033; and HR 2.00, 95% CI: 1.04-3.84, p = 0.037 respectively). Comparable results were obtained when excluding uncommon histotypes (TAZ/CTGF: HR 2.34, 95% CI: 1.16-4.73, p = 0.018. YAP/CTGF. HR 2.36, 95% CI: 1.17-4.77, p = 0.017). Overall, the TAZ/YAP-driven oncogenic program may be active in MBC, conferring poorer survival.

Breast carcinomas with low amplified/equivocal HER2 by Ish: potential supporting role of multiplex ligation-dependent probe amplification

BACKGROUND

This is a retrospective cross sectional study aimed to verify whether Multiplex Ligation-dependent Probe Amplification (MLPA), a quantitative molecular assay, may represent a valuable reflex test in breast cancer with equivocal HER2 expression by immunohistochemistry and HER2 gene signals/nucleus (s/n) ranging between 4.0 and 5.9 by in situ hybridization.

METHODS

A series of 170 breast carcinomas scored as 2+ for HER2 expression by immunohistochemistry, were selected from our files and analyzed in parallel by silver in situ hybridization and by MLPA. According to ASCO-CAP 2013 guidelines, 54/170 tumors, displaying 4.0-5.9 HER2 gene s/n, were defined as low amplified (ratio ≥ 2) or equivocal (ratio < 2) on the basis of centromere enumeration probe 17 (CEP17) status. An independent set of 108 score 2+ breast cancers represented the external validation set. Concordance between the two techniques was assessed through the use of Cohen's K statistic.

RESULTS

A concordance rate of 78.2% (Cohen's K statistic: 0,548 95% CI:[0,419-0,677]) between in situ hybridization and MLPA was found in the whole series of 170 cases and of 55.5% (Cohen's K statistic: -0,043 95% CI:[-0,271-0,184]) in the 54 tumors presenting 4.0-5.9 HER2 gene s/n. By MLPA, we found HER2 amplification or gain in 14% of the 21 BC presenting a disomic status and in 18% of the 33 BC presenting a CEP17 > 2.0. These data were further confirmed in the external validation set. Interestingly, the 54 low amplified/equivocal breast carcinomas presented a frequency of hormonal receptor positivity significantly higher than that observed in the amplified tumors and similar to the non-amplified one (p = 0.016 for estrogen receptor and p = 0.001 for progesterone receptor).

CONCLUSIONS

To avoid to offer patients an ineffective therapy, HER2 status should be studied more thoroughly in low amplified and equivocal cases which can have lower response rates and shorter time to progression to trastuzumab. In this context, our data indicate that MLPA may be a reliable, objective supporting test in selecting HER2 positive breast cancer patients.

SIRT6 interacts with TRF2 and promotes its degradation in response to DNA damage

Telomere repeat binding factor 2 (TRF2) has been increasingly recognized to be involved in telomere maintenance and DNA damage response. Here, we show that TRF2 directly binds SIRT6 in a DNA independent manner and that this interaction is increased upon replication stress. Knockdown of SIRT6 up-regulates TRF2 protein levels and counteracts its down-regulation during DNA damage response, leading to cell survival. Moreover, we report that SIRT6 deactetylates in vivo the TRFH domain of TRF2, which in turn, is ubiquitylated in vivo activating the ubiquitin-dependent proteolysis. Notably, overexpression of the TRF2cT mutant failed to be stabilized by SIRT6 depletion, demonstrating that the TRFH domain is required for its post-transcriptional modification. Finally, we report an inverse correlation between SIRT6 and TRF2 protein expression levels in a cohort of colon rectal cancer patients. Taken together our findings describe TRF2 as a novel SIRT6 substrate and demonstrate that acetylation of TRF2 plays a crucial role in the regulation of TRF2 protein stability, thus providing a new route for modulating its expression level during oncogenesis and damage response.

Analysis of the ATR-Chk1 and ATM-Chk2 pathways in male breast cancer revealed the prognostic significance of ATR expression

The ATR-Chk1 and ATM-Chk2 pathways are central in DNA damage repair (DDR) and their over-activation may confer aggressive molecular features, being an adaptive response to endogenous DNA damage and oncogene-induced replication stress. Herein we investigated the ATR-Chk1 and ATM-Chk2 signalings in male breast cancer (MBC). The expression of DDR kinases (pATR, pATM, pChk1, pChk2, and pWee1) and DNA damage markers (pRPA32 and γ-H2AX) was evaluated by immunohistochemistry in 289 MBC samples to assess their association. Survival analyses were carried out in 112 patients. Survival curves were estimated with the Kaplan-Meier method and compared by log-rank test. Cox proportional regression models were generated to identify variables impacting survival outcomes. The expression of pATR conferred poorer survival outcomes (log rank p = 0.013, p = 0.007 and p = 0.010 for overall, 15- and 10-year survival, respectively). Multivariate Cox models of 10-year survival and overall indicated that pATR expression, alone or combined with pChk2, was an independent predictor of adverse outcomes (10-year survival: pATR: HR 2.74, 95% CI: 1.23-6.10; pATR/pChk2: HR 2.92, 95% CI: 1.35-6.33; overall survival: pATR: HR 2.58, 95% CI: 1.20-5.53; pATR/pChk2: HR 2.89, 95% CI: 1.37-6.12). Overall, the ATR/ATM-initiated molecular cascade seems to be active in a fraction of MBC patients and may represent a negative prognostic factor.

Caspase-8 contributes to angiogenesis and chemotherapy resistance in glioblastoma

Caspase-8 is a key player in extrinsic apoptosis and its activity is often downregulated in cancer. However, human Caspase-8 expression is retained in some tumors, including glioblastoma (GBM), suggesting that it may support cancer growth in these contexts. GBM, the most aggressive of the gliomas, is characterized by extensive angiogenesis and by an inflammatory microenvironment that support its development and resistance to therapies. We have recently shown that Caspase-8 sustains neoplastic transformation in vitro in human GBM cell lines. Here, we demonstrate that Caspase-8, through activation of NF-kB, enhances the expression and secretion of VEGF, IL-6, IL-8, IL-1beta and MCP-1, leading to neovascularization and increased resistance to Temozolomide. Importantly, the bioinformatics analysis of microarray gene expression data derived from a set of high-grade human gliomas, shows that high Caspase-8 expression levels correlate with a worse prognosis.

DOI:http://dx.doi.org/10.7554/eLife.22593.001

Cancer cells are different to normal cells in various ways. Most cancer cells, for example, delete or switch off the gene for a protein called Caspase-8. This is because this protein is best known for promoting cell death and stopping tumor cells from growing. However, some cancers keep the gene for Caspase-8 switched on including glioblastoma, the most aggressive type of brain cancer in adults. This begged the question whether this protein may in fact promote the development of tumors under certain circumstances.

Glioblastomas are often highly resistant to chemotherapy and can communicate with nearby cells using proteins called cytokines to promote the formation of new blood vessels. The new blood vessel allows the tumor to readily spread into healthy brain tissue, which in turn makes it difficult for surgeons to remove all the cancerous cells. As a result, glioblastomas almost always return after surgery, and so there is strong need for new effective treatments for this type of cancer.

Fianco et al. have now investigated whether Caspase-8 helps glioblastomas to grow and form new blood vessels. One common method to study human cancer cells is to inject them into mice and watch how they grow, because these experiments mimic how tumors develop in the human body. When mice were injected with human glioblastoma cells with experimentally reduced levels of Caspase-8, the cells grew poorly and did not form as many new blood vessels as unaltered glioblastoma cells. Further experiments showed that, when grown in the laboratory, glioblastoma cells with less Caspase-8 were more sensitive to a chemotherapeutic drug called temozolomide. These findings confirm that Caspase-8 does boost the growth and drug resistance of at least one cancer. When Fianco et al. analyzed clinical data from patients affected by glioblastoma, they also observed that those patients with high levels of Caspase-8 often had the worse outcomes.

Previous studies conducted in white blood cells showed that Caspase-8 activated a protein complex called NF-kB, which in turn led to the cells releasing cytokines. Fianco et al. have now verified that Caspase-8 promotes NF-kB activity also in glioblastoma cells, and that this causes the cancer cells to release more cytokines. As such, these findings reveal a clear link between Caspase-8 and the formation of new blood vessels by glioblastomas.

Future studies are now needed to understand why Caspase-8 promotes cell death in some cancers but the formation of new blood vessels in others. Indeed, Caspase-8 might become a target for new anticancer drugs if it is possible to inhibit its cancer-boosting activity without interfering with its ability to promote cell death.

DOI:http://dx.doi.org/10.7554/eLife.22593.002

A Case-Matched Gender Comparison Transcriptomic Screen Identifies eIF4E and eIF5 as Potential Prognostic Markers in Male Breast Cancer

Purpose: Breast cancer affects both genders, but is understudied in men. Although still rare, male breast cancer (MBC) is being diagnosed more frequently. Treatments are wholly informed by clinical studies conducted in women, based on assumptions that underlying biology is similar.Experimental Design: A transcriptomic investigation of male and female breast cancer was performed, confirming transcriptomic data in silico Biomarkers were immunohistochemically assessed in 697 MBCs (n = 477, training; n = 220, validation set) and quantified in pre- and posttreatment samples from an MBC patient receiving everolimus and PI3K/mTOR inhibitor.Results: Gender-specific gene expression patterns were identified. eIF transcripts were upregulated in MBC. eIF4E and eIF5 were negatively prognostic for overall survival alone (log-rank P = 0.013; HR = 1.77, 1.12-2.8 and P = 0.035; HR = 1.68, 1.03-2.74, respectively), or when coexpressed (P = 0.01; HR = 2.66, 1.26-5.63), confirmed in the validation set. This remained upon multivariate Cox regression analysis [eIF4E P = 0.016; HR = 2.38 (1.18-4.8), eIF5 P = 0.022; HR = 2.55 (1.14-5.7); coexpression P = 0.001; HR = 7.04 (2.22-22.26)]. Marked reduction in eIF4E and eIF5 expression was seen post BEZ235/everolimus, with extended survival.Conclusions: Translational initiation pathway inhibition could be of clinical utility in MBC patients overexpressing eIF4E and eIF5. With mTOR inhibitors that target this pathway now in the clinic, these biomarkers may represent new targets for therapeutic intervention, although further independent validation is required. Clin Cancer Res; 23(10); 2575-83. ©2016 AACR.

Expression of phosphorylated Hippo pathway kinases (MST1/2 and LATS1/2) in HER2-positive and triple-negative breast cancer patients treated with neoadjuvant therapy

The Hippo kinases MST1/2 and LATS1/2 inhibit the oncoproteins TAZ/YAP and regulate T cell function. Hippo kinases also cooperate with the ATR-Chk1 and ATM-Chk2 pathways, central orchestrators of the DNA damage response (DDR). We hypothesized that MST1/2 and LATS1/2 localization differently impacts the efficacy of neoadjuvant therapy (NAT) in breast cancer, being protective when expressed in the cytoplasm of tumor cells and in tumor-infiltrating lymphocytes, whereas representing molecular determinants of chemoresistance when present in the nucleus as a consequence of their cooperation with the DDR. Diagnostic biopsies from 57 HER2-positive and triple-negative breast cancer patients treated with NAT were immunostained for evaluating the expression of phosphorylated MST1/2 (pMST1/2) and LATS1/2 (pLATS1/2) in tumor-infiltrating lymphocytes (TILs) and in cancer cells. TAZ and Chk1 immunostaining was exploited for investigating subcellular compartment-dependent activity of Hippo kinases. Nuclear pMST1/2 (pMST1/2^nuc) expression was significantly associated with nuclear expression of Chk1 (p = 0.046), whereas cytoplasmic pMST1/2 (pMST1/2^cyt) expression was marginally associated with cytoplasmic TAZ staining (p = 0.053). Patients whose tumors expressed pMST1/2^nuc were at increased risk of residual disease after NAT (pCR ypT0/is ypN0: OR 4.91, 95%CI: 1.57-15.30; pCR ypT0 ypN0: OR 3.59, 95%CI 1.14-11.34). Conversely, exclusive cytoplasmic localization of pMST1/2 (pMST1/2^cyt)seemed to be a protective factor (pCR ypT0/is ypN0: OR 0.34, 95%CI: 0.11-1.00; pCR ypT0 ypN0: OR 0.31, 95%CI 0.10-0.93). The subcellular localization-dependent significance of pMST1/2 expression suggests their involvement in different molecular networks with opposite impact on NAT efficacy. Larger studies are warranted to confirm these novel findings.

DNA damage repair and survival outcomes in advanced gastric cancer patients treated with first-line chemotherapy

The DNA damage response (DDR) network is exploited by cancer cells to withstand chemotherapy. Gastric cancer (GC) carries deregulation of the DDR and harbors genetic defects that fuel its activation. The ATM-Chk2 and ATR-Chk1-Wee1 axes are deputed to initiate DNA repair. Overactivation of these pathways in cancer cells may represent an adaptive response for compensating genetic defects deregulating G₁ -S transition (e.g., TP53) and ATM/ATR-initiated DNA repair (e.g., ARID1A). We hypothesized that DDR-linked biomarkers may predict clinical outcomes in GC patients treated with chemotherapy. Immunohistochemical assessment of DDR kinases (pATM, pChk2, pChk1 and pWee1) and DNA damage markers (γ-H2AX and pRPA32) was performed in biological samples from 110 advanced GC patients treated with first-line chemotherapy, either in phase II trials or in routine clinical practice. In 90 patients, this characterization was integrated with targeted ultra-deep sequencing for evaluating the mutational status of TP53 and ARID1A. We recorded a positive association between the investigated biomarkers. The combination of two biomarkers (γ-H2AX^high /pATM^high ) was an adverse factor for both progression-free survival (multivariate Cox: HR 2.23, 95%CI: 1.47-3.40) and overall survival (multivariate Cox: HR: 2.07, 95%CI: 1.20-3.58). The relationship between the γ-H2AX^high /pATM^high model and progression-free survival was consistent across the different TP53 backgrounds and was maintained in the ARID1A wild-type setting. Conversely, this association was no longer observed in an ARID1A-mutated subgroup. The γ-H2AX^high /pATM^high model negatively impacted survival outcomes in GC patients treated with chemotherapy. The mutational status of ARID1A, but apparently not TP53 mutations, affects its predictive significance.

Association between AXL, Hippo Transducers, and Survival Outcomes in Male Breast Cancer

Male breast cancer (MBC) is an uncommon malignancy. We have previously reported that the expression of the Hippo transducers TAZ/YAP and their target CTGF was associated with inferior survival in MBC patients. Preclinical evidence demonstrated that Axl is a transcriptional target of TAZ/YAP. Thus, we herein assessed AXL expression to further investigate the significance of active TAZ/YAP-driven transcription in MBC. For this study, 255 MBC samples represented in tissue microarrays were screened for AXL expression, and 116 patients were included. The association between categorical variables was verified by the Pearson's Chi-squared test of independence (2-tailed) or the Fisher Exact test. The relationship between continuous variables was tested with the Pearson's correlation coefficient. The Kaplan-Meier method was used for estimating survival curves, which were compared by log-rank test. Factors potentially impacting 10-year and overall survival were verified in Cox proportional regression models. AXL was positively associated with the TAZ/CTGF and YAP/CTGF phenotypes (P = 0.001 and P = 0.002, respectively). Patients with TAZ/CTGF/AXL- or YAP/CTGF/AXL-expressing tumors had inferior survival compared with non-triple-positive patients (log rank P = 0.042 and P = 0.048, respectively). The variables TAZ/CTGF/AXL and YAP/CTGF/AXL were adverse factors for 10-year survival in the multivariate Cox models (HR 2.31, 95%CI:1.02-5.22, P = 0.045, and HR 2.27, 95%CI:1.00-5.13, P = 0.050). Nearly comparable results were obtained from multivariate analyses of overall survival. The expression pattern of AXL corroborates the idea of the detrimental role of TAZ/YAP activation in MBC. Overall, Hippo-linked biomarkers deserve increased attention in this rare disease. J. Cell. Physiol. 232: 2246-2252, 2017. © 2016 Wiley Periodicals, Inc.

Body mass index modifies the relationship between γ-H2AX, a DNA damage biomarker, and pathological complete response in triple-negative breast cancer

Background

Body mass index (BMI) is largely investigated as a prognostic and predictive factor in triple-negative breast cancer (TNBC). Overweight and obesity are linked to a variety of pathways regulating tumor-promoting functions, including the DNA damage response (DDR). The DDR physiologically safeguards genome integrity but, in a neoplastic background, it is aberrantly engaged and protects cancer cells from chemotherapy. We herein verified the role of BMI on a previously assessed association between DDR biomarkers and pathological complete response (pCR) in TNBC patients treated with neoadjuvant chemotherapy (NACT).

Methods

In this retrospective analysis 54 TNBC patients treated with NACT were included. The relationship between DDR biomarkers, namely phosphorylated H2A Histone Family Member X (γ-H2AX) and phosphorylated checkpoint kinase 1 (pChk1), and pCR was reconsidered in light of BMI data. The Pearson’s Chi-squared test of independence (2-tailed) and the Fisher Exact test were employed to assess the relationship between clinical-molecular variables and pCR. Uni- and multivariate logistic regression models were used to identify variables impacting pCR. Internal validation was carried out.

Results

We observed a significant association between elevated levels of the two DDR biomarkers and pCR in patients with BMI < 25 (p = 0.009 and p = 0.022 for γ-H2AX and pChk1, respectively), but not in their heavier counterpart. Results regarding γ-H2AX were confirmed in uni- and multivariate models and, again, for leaner patients only (γ-H2AX^high vs γ-H2AX^low: OR 10.83, 95% CI: 1.79–65.55, p = 0.009). The consistency of this finding was confirmed upon internal validation.

Conclusions

The predictive significance of γ-H2AX varies according to BMI status. Indeed, elevated levels of γ-H2AX seemed associated with lower pCR rate only in leaner patients, whereas differences in pCR rate according to γ-H2AX levels were not appreciable in heavier patients. Larger investigations are warranted concerning the potential role of BMI as effect modifier of the relationship between DDR-related biomarkers and clinical outcomes in TNBC.

Functional and prognostic significance of the genomic amplification of frizzled 6 (FZD6) in breast cancer

Frizzled receptors mediate Wnt ligand signalling, which is crucially involved in regulating tissue development and differentiation, and is often deregulated in cancer. In this study, we found that the gene encoding the Wnt receptor frizzled 6 (FZD6) is frequently amplified in breast cancer, with an increased incidence in the triple‐negative breast cancer (TNBC) subtype. Ablation of FZD6 expression in mammary cancer cell lines: (1) inhibited motility and invasion; (2) induced a more symmetrical shape of organoid three‐dimensional cultures; and (3) inhibited bone and liver metastasis in vivo. Mechanistically, FZD6 signalling is required for the assembly of the fibronectin matrix, interfering with the organization of the actin cytoskeleton. Ectopic delivery of fibronectin in FZD6‐depleted, triple‐negative MDA‐MB‐231 cells rearranged the actin cytoskeleton and restored epidermal growth factor‐mediated invasion. In patients with localized, lymph node‐negative (early) breast cancer, positivity of tumour cells for FZD6 protein identified patients with reduced distant relapse‐free survival. Multivariate analysis indicated an independent prognostic significance of FZD6 expression in TNBC tumours, predicting distant, but not local, relapse. We conclude that the FZD6–fibronectin actin axis identified in our study could be exploited for drug development in highly metastatic forms of breast cancer, such as TNBC. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Predictive significance of DNA damage and repair biomarkers in triple-negative breast cancer patients treated with neoadjuvant chemotherapy: An exploratory analysis

Response of cancer cells to chemotherapy-induced DNA damage is regulated by the ATM-Chk2 and ATR-Chk1 pathways. We investigated the association between phosphorylated H2AX (γ-H2AX), a marker of DNA double-strand breaks that trigger the ATM-Chk2 cascade, and phosphorylated Chk1 (pChk1), with pathological complete response (pCR) in triple-negative breast cancer (TNBC) patients treated with neoadjuvant chemotherapy. γ-H2AX and pChk1 were retrospectively assessed by immunohistochemistry in a series of pretreatment biopsies related to 66 patients. In fifty-three tumors hormone receptor status was negative in both the diagnostic biopsies and residual cancers, whereas in 13 cases there was a slight hormone receptor expression that changed after chemotherapy. Internal validation was carried out. In the entire cohort elevated levels of γ-H2AX, but not pChk1, were associated with reduced pCR rate (p = 0.009). The association tested significant in both uni- and multivariate logistic regression models (OR 4.51, 95% CI: 1.39–14.66, p = 0.012, and OR 5.07, 95% CI: 1.28–20.09, p = 0.021, respectively). Internal validation supported the predictive value of the model. The predictive ability of γ-H2AX was further confirmed in the multivariate model after exclusion of tumors that underwent changes in hormone receptor status during chemotherapy (OR 7.07, 95% CI: 1.39–36.02, p = 0.018). Finally, in residual diseases a significant decrease of γ-H2AX levels was observed (p < 0.001). Overall, γ-H2AX showed ability to predict pCR in TNBC and deserves larger, prospective studies.

HMG-CoAR expression in male breast cancer: relationship with hormone receptors, Hippo transducers and survival outcomes

Male breast cancer (MBC) is a rare hormone-driven disease often associated with obesity. HMG-CoAR is the central enzyme of the mevalonate pathway, a molecular route deputed to produce cholesterol and steroid-based hormones. HMG-CoAR regulates the oncogenic Hippo transducers TAZ/YAP whose expression was previously associated with shorter survival in MBC. 225 MBC samples were immunostained for HMG-CoAR and 124 were considered eligible for exploring its relationship with hormone receptors (ER, PgR, AR), Hippo transducers and survival outcomes. HMG-CoAR was positively associated with the expression of hormone receptors (ER, PgR, AR) and Hippo transducers. Overall survival was longer in patients with HMG-CoAR-positive tumors compared with their negative counterparts (p = 0.031). Five- and 10-year survival outcomes were better in patients whose tumors expressed HMG-CoAR (p = 0.044 and p = 0.043). Uni- and multivariate analyses for 10-year survival suggested that HMG-CoAR expression is a protective factor (HR 0.50, 95% CI: 0.25–0.99, p = 0.048 and HR 0.53, 95% CI: 0.26–1.07, p = 0.078). Results were confirmed in a sensitivity analysis by excluding uncommon histotypes (multivariate Cox: HR 0.45, 95% CI: 0.21–0.97, p = 0.043). A positive relationship emerged between HMG-CoAR, hormone receptors and TAZ/YAP, suggesting a connection between the mevalonate pathway, the hormonal milieu and Hippo in MBC. Moreover, HMG-CoAR expression may be a favorable prognostic indicator.

Gender effects of single nucleotide polymorphisms and miRNAs targeting clock-genes in metastatic colorectal cancer patients (mCRC)

The circadian system is composed of a set of clock-genes including PERIOD, CLOCK, BMAL1 and CRY. Disrupting this system promotes cancer development and progression. The expression levels of miR-206, miR-219, miR-192, miR-194 and miR-132 regulating clock-genes and three functional polymorphisms rs11133373 C/G, rs1801260 T/C, rs11133391 T/C in CLOCK sequence were associated with the survival of 83 mCRC patients (50 males and 33 females). Longer overall survival (OS) was observed in women compared to men, 50 versus 31 months. This difference was associated with rs11133373 C/C genotype (p = 0.01), rs1801260 T/C+C/C genotype (p = 0.06) and rs11133391 T/T genotype (p = 0.06). Moreover women expressing high levels (H) of miR-192 (p = 0.03), miR-206 (p = 0.003), miR-194 (p = 0.02) and miR-219 (p = 0.002) had a longer OS compared to men. In women longer OS was reinforced by the simultaneous presence of two or more H-miR, 58 months versus 15 months (p = 0.0008); in this group of women an OS of 87 months was reached with the additional presence of rs11133391T/T genotype (p = 0.02). In this study we identified a subgroup of female patients who seems to have a better prognosis. Personalized medicine should prospectively take into account both genetic and gender differences.

Presurgical window of opportunity trial design as a platform for testing anticancer drugs: Pros, cons and a focus on breast cancer

The high attrition rate is a major issue in anticancer drug development. Among the alternative trial designs, presurgical window of opportunity trials envision a short course treatment in the time window between diagnostic biopsy and surgery in a moderately-sized patient population. This approach allows testing therapeutics when pre- and post-treatment tumor tissues are available for comprehensive molecular analyses. The emerging evidence may help define the ability of a given agent to modulate its target(s) and help obtain a broader picture of the molecular changes operated by the treatment. The resulting gain may outweigh the potential harms for patients in the early disease setting. Window of opportunity trials have been extensively applied to breast cancer. Overall, a wider use of these trial designs might lead to the identification of potential responders, ineffective drugs or combinations, and ultimately contribute to enhance the efficiency of the clinical developmental process.

Dual targeting of HER3 and MEK may overcome HER3-dependent drug-resistance of colon cancers

Although the medical treatment of colorectal cancer has evolved greatly in the last years, a significant portion of early-stage patients develops recurrence after therapies. The current clinical trials are directed to evaluate new drug combinations and treatment schedules.

By the use of patient-derived or established colon cancer cell lines, we found that the tyrosine kinase receptor HER3 is involved in the mechanisms of resistance to therapies. In agreement, the immunohistochemical analysis of total and phospho-HER3 expression in 185 colorectal cancer specimens revealed a significant correlation with lower disease-free survival.

Targeting HER3 by the use of the monoclonal antibody patritumab we found induction of growth arrest in all cell lines. Despite the high efficiency of patritumab in abrogating the HER3-dependent activation of PI3K pathway, the HER2 and EGFR-dependent MAPK pathway is activated as a compensatory mechanism. Interestingly, we found that the MEK-inhibitor trametinib inhibits, as expected, the MAPK pathway but induces the HER3-dependent activation of PI3K pathway. The combined treatment results in the abrogation of both PI3K and MAPK pathways and in a significant reduction of cell proliferation and survival.

These data suggest a new strategy of therapy for HER3-overexpressing colon cancers.

Abstract 266: The G-quadruplex ligand EMICORON potentiates the antitumor efficacy of chemotherapy on colon cancer experimental models

Background. G-quadruplex (G4) structures, present at the telomeric ends of chromosomes and in the promoters of a wide range of genes important in cell signaling, gained interest as therapeutic targets and several small molecules able to bind and stabilize G4 structures have been developed. However, due to the poor drug-like properties and/or selectivity profile none of the G4 ligands has progressed through the drug discovery pipeline. Our group recently showed that the novel G4 ligand EMICORON exhibited a favourable pharmacological profile, was well tolerated in mice and elicited antitumor efficacy against advanced experimental models of colon cancer. Based on these results, our aim was to study the ability of EMICORON to increase the efficacy of the standard chemotherapy for human colon cancer.

Matherials and Methods. We assessed the in vitro cytotoxic activity of EMICORON in combination with SN-38, 5-Fluorouracil and Oxaliplatin by clonogenic and 3D tumor-spheroid formation assay on HT29 colon cancer cells. The combination index (CI) values indicating synergism (CI 0.9 1.2) was evaluated. In vivo experiments were performed in mice bearing HT29 tumors treated with Irinotecan followed by EMICORON in one or two cycles of administration. Moreover, efficacy of the standard FOLFIRI (5-Fluorouracil, Leucovorin and Irinotecan) or FOLFOX (5-Fluorouracil, Leucovorin and Oxaliplatin) was evaluated in two different colon cancer patient-derived xenografts (PDXs).

Results and conclusions. The exposure of HT29 cells to the combination of EMICORON with chemotherapeutics resulted strongly synergistic when the drugs were administered following the sequence SN-38→EMICORON, EMICORON→5-Fluoruracil or EMICORON→Oxaliplatin, while the opposite sequences were additive or slightly antagonistic. The high activity of SN-38 followed by EMICORON was confirmed in the HT29-formed spheroids. When mice bearing HT29 xenografts were treated with EMICORON or Irinotecan, a tumor weight inhibition (TWI) of 35 or 65% was observed respectively, while the treatment with Irinotecan followed by EMICORON resulted more effective with a TWI of 80%. This marked antitumor effect of the combination produced an increase in overall survival of mice of 85%. Interestingly, the administration of a second cycle of treatment produced an impressive increase of survival of mice to 114%. Then, we tested the efficacy of FOLFOX or FOLFIRI therapeutic regimens on two colon cancer PDXs and as expected these treatments were very effective in reducing the tumor mass and delaying the tumor regrowth, but the relapse of the disease was observed in all the mice. In conclusion, our results demonstrating that EMICORON is able to increase the potency of any single drug, provide a compelling argument to suggest that the integration of EMICORON in standard chemotherapeutic regimens could be a highly valuable strategy.

Citation Format: Manuela Porru, Simona Artuso, Luca Pompili, Carla Caruso, Armandodoriano Bianco, Marcella Mottolese, Carla A. Amoreo, Annamaria Biroccio, Carlo Leonetti. The G-quadruplex ligand EMICORON potentiates the antitumor efficacy of chemotherapy on colon cancer experimental models. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 266.

Neoadjuvant Sequential Docetaxel Followed by High-Dose Epirubicin in Combination With Cyclophosphamide Administered Concurrently With Trastuzumab. The DECT Trial

To report the results of the DECT trial, a phase II study of locally advanced or operable HER2-positive breast cancer (BC) treated with taxanes and concurrent anthracyclines and trastuzumab. Eligible patients (stage IIA-IIIB HER2-positive BC, 18-75 years, normal organ functions, ECOG ≤1, and left ventricular ejection fraction (LVEF) ≥55%) received four cycles of neoadjuvant docetaxel, 100 mg/m(2) intravenously, plus trastuzumab 6 mg/kg (loading dose 8 mg/kg) every 3 weeks, followed by four 3-weekly cycles of epirubicin 120 mg/m(2) and cyclophosphamide, 600 mg/m(2) , plus trastuzumab. Primary objective was pathologic complete response (pCR) rate, defined as ypT0/is ypN0 at definitive surgery. We enrolled 45 consecutive patients. All but six patients (13.3%) completed chemotherapy and all underwent surgery. pCR was observed in 28 patients (62.2%) overall and in 6 (66.7%) from the inflammatory subgroup. The classification and regression tree analysis showed a 100% pCR rate in patients with BMI ≥25 and with hormone negative disease. The median follow up was 46 months (8-78). Four-year recurrence-free survival was 74.7% (95%CI, 58.2-91.2). Seven patients (15.6%) recurred and one died. Treatment was well tolerated, with limiting toxicity being neutropenia. No clinical cardiotoxicity was observed. Six patients (13.4%) showed a transient LVEF decrease (<10%). In one patient we observed a ≥10% asymptomatic LVEF decrease persisting after surgery. Notwithstanding their limited applicability due to the current guidelines, our findings support the efficacy of the regimen of interest in the neoadjuvant setting along with a fairly acceptable toxicity profile, including cardiotoxicity. Results on BMI may invite further assessment in future studies. J. Cell. Physiol. 231: 2541-2547, 2016. © 2016 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.

Topographic expression of the Hippo transducers TAZ and YAP in triple-negative breast cancer treated with neoadjuvant chemotherapy

Background

The Hippo signaling acts as a tumor-suppressor pathway that negatively regulates TAZ and YAP. Increasing evidence supports the activation of TAZ and YAP in breast cancer. Moreover, the Hippo pathway is involved in the biology of non-neoplastic cells residing in the tumor microenvironment. On this basis, we herein assessed TAZ and YAP in triple-negative breast cancer and its surrounding microenvironemnt in order to investigate their impact on pathological complete response (pCR) and tumor recurrence.

Methods

Sixty-one triple-negative breast cancer patients treated with neoadjuvant chemotherapy were retrospectively evaluated. TAZ and YAP were assessed by immunohistochemistry and classified as positive or negative according to the percentage of tumor-expressing cells, cellular localization, and staining intensity. TAZ and YAP expression was also evaluated in non-lymphocytic stromal cells, tumor-infiltrating lymphocytes (TILs) and endothelial cells. The Pearson’s Chi-squared test of independence was used to test the association between TAZ/YAP and clinical-molecular factors. A multivariate logistic regression model was generated to identify variables impacting pCR. The Kaplan-Meier method and the log-rank test were used for estimating and comparing survival curves. Cox proportional regression models were built to evaluate the risk of recurrence for the variables considered. Internal validation was carried out with a re-sampling without replacement method.

Results

We did not observe any impact on pCR rate when TAZ and YAP were addressed singularly. Conversely, the combined expression of YAP in tumor cells and non-lymphocytic stromal cells was an independent predictor of reduced pCR rate in the multivariate model (OR 7.13, 95 % CI: 1.23–41.41, p = 0.029). Next, the combined expression of TAZ and YAP was associated with shorter disease-free survival (DFS) in multivariate analysis (HR 3.07, 95 % CI: 1.24–7.61, p = 0.016). The robustness of these findings were internally validated.

Conclusions

The combined expression of YAP in TNBC cells and in the surrounding stroma seems to be associated with a decreased likelihood to achieve pCR. Conversely, the combined expression of TAZ and YAP in tumor cells conferred poor survival outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0338-7) contains supplementary material, which is available to authorized users.

Analysis of the hippo transducers TAZ and YAP in cervical cancer and its microenvironment

Hippo is a tumor-suppressor pathway that negatively regulates the oncoproteins TAZ and YAP. Moreover, Hippo affects the biology of a variety of non-neoplastic cells in the tumor microenvironment, even including immune cells. We herein assessed the predictive role of TAZ and YAP, assessed by immunohistochemistry, in 50 cervical cancer patients prevalently treated with neoadjuvant chemotherapy. Tumors were classified as positive or negative according to the percentage of tumor-expressing cells and cellular localization. TAZ/YAP were also evaluated in non-neoplastic cells, namely endothelial cells, non-lymphocytic stromal cells and tumor-infiltrating lymphocytes (TILs). TAZ expression in cancer cells (TAZ(pos)) was associated with a reduced pathological complete response (pCR) rate (p = 0.041). Conversely, the expression of TAZ and YAP in TILs (TAZ(TIL+) and YAP(TIL+)) seemed to be associated with increased pCRs (p = 0.083 and p = 0.018, respectively). When testing the predictive significance of the concomitant expression of TAZ in cancer cells and its absence in TILs (TAZ(pos)/TAZ(TIL-)), patients with TAZ(pos)/TAZ(TIL-) showed lower pCR rate (p = 0.001), as confirmed in multivariate analysis (TAZ(pos)/TAZ(TIL-): OR 8.67, 95% CI: 2.31-32.52, p = 0.001). Sensitivity analysis carried out in the 41 patients treated with neoadjuvant chemotherapy yielded comparable results (TAZ(pos)/TAZ(TIL-): OR 11.0, 95% CI: 2.42-49.91, p = 0.002). Internal validation carried out with two different procedures confirmed the robustness of this model. Overall, we found evidence on the association between TAZ expression in cervical cancer cells and reduced pCR rate. Conversely, the expression of the Hippo transducers in TILs may predict increased treatment efficacy, possibly mirroring the activation of a non-canonical Hippo/MST pathway necessary for T-cells activation and survival.

DNA Damage and Repair Biomarkers in Cervical Cancer Patients Treated with Neoadjuvant Chemotherapy: An Exploratory Analysis

Cervical cancer cells commonly harbour a defective G₁/S checkpoint owing to the interaction of viral oncoproteins with p53 and retinoblastoma protein. The activation of the G₂/M checkpoint may thus become essential for protecting cancer cells from genotoxic insults, such as chemotherapy. In 52 cervical cancer patients treated with neoadjuvant chemotherapy, we investigated whether the levels of phosphorylated Wee1 (pWee1), a key G₂/M checkpoint kinase, and γ-H2AX, a marker of DNA double-strand breaks, discriminated between patients with a pathological complete response (pCR) and those with residual disease. We also tested the association between pWee1 and phosphorylated Chk1 (pChk1), a kinase acting upstream Wee1 in the G₂/M checkpoint pathway. pWee1, γ-H2AX and pChk1 were retrospectively assessed in diagnostic biopsies by immunohistochemistry. The degrees of pWee1 and pChk1 expression were defined using three different classification methods, i.e., staining intensity, Allred score, and a multiplicative score. γ-H2AX was analyzed both as continuous and categorical variable. Irrespective of the classification used, elevated levels of pWee1 and γ-H2AX were significantly associated with a lower rate of pCR. In univariate and multivariate analyses, pWee1 and γ-H2AX were both associated with reduced pCR. Internal validation conducted through a re-sampling without replacement procedure confirmed the robustness of the multivariate model. Finally, we found a significant association between pWee1 and pChk1. The message conveyed by the present analysis is that biomarkers of DNA damage and repair may predict the efficacy of neoadjuvant chemotherapy in cervical cancer. Further studies are warranted to prospectively validate these encouraging findings.

Prospective study on nanoparticle albumin-bound paclitaxel in advanced breast cancer: clinical results and biological observations in taxane-pretreated patients

Background

There is a deep need to improve the care of metastatic breast cancer (MBC) patients, since even today it remains an incurable disease. Taxanes are considered the most effective cytotoxic drugs for the treatment of MBC, both in monotherapy and in combined schedules, but the need for synthetic solvents contributes to the severe toxicities and may have a negative impact on the efficacy. Nanoparticle albumin-bound paclitaxel (Nab-paclitaxel) is a colloidal suspension of paclitaxel and human serum albumin initially developed to avoid the toxicities associated with conventional taxanes.

Patients and methods

The aim of this prospective, single-center open-label, noncomparative study was to evaluate the efficacy and safety of nab-paclitaxel in MBC patients pretreated with taxanes. The patients were treated with nab-paclitaxel as a single agent, 260 mg/m² on day 1 of each 3-week cycle or 125 mg/m² weekly. The primary endpoint was the overall response rate (ORR). Secondary objectives were duration of response, clinical benefit rate, progression-free survival (PFS), overall survival, and safety.

Results

A total of 42 patients (median age 48 years, median Eastern Cooperative Oncology Group performance status 0, triple-negative MBC 19%, all pretreated with a taxane-based therapy, mainly in advanced disease) were enrolled in the study. The ORR was 23.8%, including one complete response (2.4%) and nine partial responses (21.4%); the disease control rate was 50%. The median duration of response was 7.2 months. After a median follow-up of 9 months, the median PFS was 4.6 months. ORR and PFS were similar irrespective of the previous chemotherapy lines, metastatic sites, and biomolecular expression. Nab-paclitaxel was well tolerated, and the most frequent treatment-related toxicities were mild to moderate (grades 1–2).

Conclusion

This real-life study shows that nab-paclitaxel has a significant antitumor activity and a manageable safety profile in patients pretreated with taxanes and experiencing a treatment failure after at least one line of chemotherapy.

Prognostic impact of alternative splicing-derived hMENA isoforms in resected, node-negative, non-small-cell lung cancer

Risk assessment and treatment choice remain a challenge in early non-small-cell lung cancer (NSCLC). Alternative splicing is an emerging source for diagnostic, prognostic and therapeutic tools. Here, we investigated the prognostic value of the actin cytoskeleton regulator hMENA and its isoforms, hMENA^11a and hMENAΔv6, in early NSCLC.

The epithelial hMENA^11a isoform was expressed in NSCLC lines expressing E-CADHERIN and was alternatively expressed with hMENAΔv6. Enforced expression of hMENAΔv6 or hMENA^11a increased or decreased the invasive ability of A549 cells, respectively. hMENA isoform expression was evaluated in 248 node-negative NSCLC. High pan-hMENA and low hMENA^11a were the only independent predictors of shorter disease-free and cancer-specific survival, and low hMENA^11a was an independent predictor of shorter overall survival, at multivariate analysis. Patients with low pan-hMENA/high hMENA^11a expression fared significantly better (P≤0.0015) than any other subgroup. Such hybrid variable was incorporated with T-size and number of resected lymph nodes into a 3-class-risk stratification model, which strikingly discriminated between different risks of relapse, cancer-related death, and death. The model was externally validated in an independent dataset of 133 patients.

Relative expression of hMENA splice isoforms is a powerful prognostic factor in early NSCLC, complementing clinical parameters to accurately predict individual patient risk.

Androgen receptor and antiandrogen therapy in male breast cancer

Cancers arising in the male breast are uncommon. Male breast cancer is a hormone-driven disease that often expresses the estrogen receptor, and antiestrogen therapy represents the mainstay of treatment. Paradoxically, the advent of a wave of antiestrogens eclipsed the therapeutic potential of alternative therapeutic options. At the beginning of the hormonal therapy era the administration of antiandrogens to metastatic male breast cancer patients was proposed. Ever since the use of these compounds has largely been neglected. A therapeutic role for antiandrogens has been envisioned again in recent years. First, molecular characterization efforts pointed to the androgen receptor as a potential therapeutic target. Second, the development of aromatase inhibitors unexpectedly raised the need for neutralizing androgens in order to tackle endocrine feedback mechanisms responsible for acquired resistance. We herein provide an overview of molecular studies where the androgen receptor was investigated at the genomic, transcriptomic or phenotypic level. We then discuss androgens in the context of the endocrine networks nourishing male breast cancer. Finally, clinical evidence on antiandrogens is summarized along with strategies should be implemented to improve the medical management of these patients.

p53 status as effect modifier of the association between pre-treatment fasting glucose and breast cancer outcomes in non diabetic, HER2 positive patients treated with trastuzumab

Mounting evidence supports the role of p53 in metabolic processes involved in breast carcinogenesis. We investigated whether p53 status affects the association of pre-treatment fasting glucose with treatment outcomes in 106 non diabetic, HER2 positive breast cancer patients treated with trastuzumab. p53 status was validated against gene sequencing of selected codons in 49 patients. The Kaplan-Meier method and log rank test were used to compare survival by categories of fasting glucose in the overall population and separate settings. Cox models included age and body mass index. Direct sequencing confirmed the lack of mutations in 73.7% of p53 negative patients and their presence in 53.3% of p53 positive cases. At 66 months, 88.3% of patients with glucose ≤ 89.0 mg/dl (median value) did not experiment disease progression compared with 70.0% in the highest category (p=0.034), with glucose being an independent predictor (p=0.046). Stratified analysis confirmed this association in p53 negative patients only (p=0.01). In the early setting, data suggested longer disease free survival in p53 negative patients in the lowest glucose category (p=0.053). In our study, p53 status acted as effect modifier of the investigated association. This may help differentiate target sub-groups and affect outcomes interpretation in similarly characterized patients.

Anthropometric, metabolic and molecular determinants of human epidermal growth factor receptor 2 expression in luminal B breast cancer

Genomic and trascriptomic profiling has recently contributed details to the characterization of luminal B breast cancer. We explored the contribution of anthropometric, metabolic, and molecular determinants to the multifaceted heterogeneity of this breast cancer subtype, with a specific focus on the association between body mass index (BMI), pre-treatment fasting glucose, hormone receptors, and expression of human epidermal growth factor receptor 2 (HER2). Extensively annotated specimens were obtained from 154 women with luminal B breast cancer diagnosed at two Italian comprehensive cancer centres. Participants' characteristics were descriptively analyzed overall and by HER2 status (positive vs. negative). BMI (<25 vs ≥25), pre-treatment fasting glucose (<median value of 94 mg/dl vs. ≥94) and percentage of hormone receptors were tested for association with HER2 expression in regression models. In univariate models, BMI, fasting glucose and, at a lesser extent, percentage of estrogen receptors (ER) were significantly and inversely associated with HER2 expression (OR: 0.32, 95% CI: 0.16-0.66; 0.43, 0.23-0.82; 0.96, 0.94-0.97, respectively). The multivariate models confirmed the protective role of BMI and ER on HER2 expression, with luminal B HER2 positive patients being significantly less frequent among women within the highest category of BMI and percentage expression of ER compared with their counterparts (OR: 0.22, 95% CI: 0.09-0.53; 0.95, 0.93-0.97). In conclusions, BMI and percentage of ER representation are inversely associated with HER2 expression in luminal B breast cancers. Upon confirmatory findings, this might help identify patient subgroups who may best benefit from the use of interventions targeting insulin resistance in well depicted breast cancer scenarios.

The Hippo transducer TAZ as a biomarker of pathological complete response in HER2-positive breast cancer patients treated with trastuzumab-based neoadjuvant therapy

Activation of the Hippo transducer TAZ is emerging as a novel oncogenic route in breast cancer and it has been associated with breast cancer stem cells. Additionally, TAZ expression has been linked with HER-2 positivity. We investigated the association between TAZ expression and pathological complete response in HER2-positive breast cancer patients treated with trastuzumab-based neoadjuvant therapy. TAZ was assessed in diagnostic core biopsies by immunohistochemistry. To categorize samples with low TAZ and samples with high TAZ we generated a score by combining staining intensity and cellular localization. The pathological complete response rate was 78.6% in patients with low TAZ tumors and 57.6% in patients with high TAZ tumors (p=0.082). In HER2-enriched tumors there was no significant association between TAZ and pathological complete response, whereas in the luminal B subtype the pathological complete response rate was 82.4% in tumors with low TAZ and 44.4% in tumors with high TAZ (p=0.035). This association remained statistically significant when restricting our analysis to triple-positive tumors with expression of both estrogen receptor and progesterone receptor ≥ 50% (p=0.035). Results from this exploratory study suggest that the TAZ score efficiently predicts pathological complete response in Luminal B, HER2-positive breast cancer patients who received neoadjuvant chemotherapy and trastuzumab.

Cancer stem cells: are they responsible for treatment failure?

Overcoming resistance to standard anticancer treatments represents a significant challenge. The interest regarding cancer stem cells, a cellular population that has the ability to self-renew and to propagate the tumor, was prompted by experimental evidence delineating the molecular mechanisms that are selectively activated in this cellular subset in order to survive chemotherapy. This has also stimulated combination strategies aimed at rendering cancer stem cells vulnerable to anticancer agents. Moreover, cancer stem cells offer a unique opportunity for modeling human cancers in mice, thus emerging as a powerful tool for testing novel drugs and combinations in a simulation of human disease. These novel animal models may lay the foundation for a new generation of clinical trials aimed at anticipating the benefit to patients of anticancer therapies.

Abstract A60: The hMENA Splicing Program: An important regulator of TGFβ1-driven EMT and invasiveness in pancreatic cancer

Background: The pancreatic ductal adenocarcinoma tumor microenvironment plays an important role in promoting the epithelial to mesenchymal transition (EMT), an early event in pancreatic cancer, involved in cancer invasiveness and in tumor progression. Among the stromal components the cancer-associated fibroblasts (CAFs) are responsible for the peculiar pancreatic tumor microenvironment and are known to be linked to the induction of EMT.

The EMT process requires a dynamic remodeling of the actin cytoskeleton and we have suggested that the splicing program of hMENA, an actin regulator, play a role in EMT. Two alternatively expressed isoforms, hMENA11a and hMENAΔv6, with opposite functions in invasiveness have been described in breast cancer (Di Modugno et al PNAS 2012).

hMENA expression has not been detected in normal pancreatic ducts, whereas expressed in the human pancreatic ductal adenocarcinoma (PDAC) samples, but no data are available on hMENA alternative isoform expression in this neoplasia.

The aim of this study is to investigate whether TGFβ1-mediated EMT in pancreatic cancer cells is affected by hMENA overexpression and splicing and how CAFs affect this process in cancer cell lines and in human tissues.

Methods: hMENA isoform expression was evaluated in PDAC tissues by immunohistochemistry using isoform specific antibodies. hMENA isoforms and EMT markers expression were characterized in human PDAC cell lines, TGFβ1-treated or untreated, by qRT-PCR and WB analysis. The effects of either hMENA isoform specific knockdown or overexpression in the TGFβ1-induced EMT were also evaluated.

Pancreatic CAFs were isolated from human tissues of resected PDAC patients. The effect of the conditioned medium of cultured CAFs was evaluated on hMENA expression. In parallel, the role of CAF-cancer cell interaction on the expression of the different hMENA isoforms was analysed using a co-culture system.

Results: Freshly explanted CAFs expressed the “mesenchymal” hMENAΔv6, and not hMENA11a and secreted paracrine factors involved in the induction of hMENA isoforms in tumor cells.

In a panel of pancreatic cancer cell lines, hMENA11a expression correlated with an epithelial phenotype, while hMENAΔv6 expression was correlated with a mesenchymal phenotype. Interestingly, the expression of the invasive hMENAΔv6 isoform is specifically up-regulated by TGFβ1 treatment.

hMENA isoform expression levels influenced molecular changes induced by TGFβ1. Thus, the hMENA11a specific silencing led to E-cadherin down-regulation that is more evident in TGFβ1 treated cells. On the contrary, hMENA11a overexpression led to a reduction of vimentin expression and to E-cadherin up-regulation. Knockdown of the endogenous hMENA/hMENAΔv6 isoform expression prevented the activation of TGFβ1 signaling and up-regulation of mesenchymal markers. In addition, hMENA/hMENAΔv6 isoform depletion impaired the TGFβ1-induced invasiveness, migration and production of MMPs.

IHC analysis of PDAC tissues revealed that the epithelial hMENA11a is rarely expressed in primary pancreatic tumour, while high levels of hMENA and hMENAΔv6 isoforms were found in 75% of primary tumours analysed.

Conclusions: This data suggests that the lack of the epithelial hMENA11a isoform is an early event in pancreatic cancer, provides new insights into the role of hMENA splicing in TGFβ1-mediated EMT and highlights hMENA splicing program as an attractive pathway for the development of new therapies in PDAC.

Citation Format: Roberta Melchionna, Pierluigi Iapicca, Francesca Di Modugno, Paola Trono, Novella Gualtieri, Maria Grazia Diodoro, Marcella Mottolese, Gian Luca Grazi, Matteo Fassan, Aldo Scarpa, Mina J. Bissell, Paola Nisticò. The hMENA Splicing Program: An important regulator of TGFβ1-driven EMT and invasiveness in pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr A60.

Role of gonadotropin-releasing hormone analogues in metastatic male breast cancer: results from a pooled analysis

Background

Male breast cancer is a rare malignancy. Despite the lack of prospectively generated data from trials in either the adjuvant or metastatic setting, patients are commonly treated with hormone therapies. Much controversy exists over the use of gonadotropin-releasing hormone analogues in metastatic male breast cancer patients. We conducted this study to provide more concrete ground on the use of gonadotropin-releasing hormone analogues in this setting.

Methods

We herein present results from a pooled analysis including 60 metastatic male breast cancer patients treated with either an aromatase inhibitor or cyproterone acetate as a monotherapy (23 patients) or combined with a gonadotropin-releasing hormone analogue (37 patients).

Results

Overall response rate was 43.5 % in patients treated with monotherapy and 51.3 % with combination therapy (p = 0.6). Survival outcomes favored combination therapy in terms of median progression-free survival (11.6 months versus 6 months; p = 0.05), 1-year progression-free survival rate (43.2 % versus 21.7 %; p = 0.05), median overall survival (29.7 months versus 22 months; p = 0.05), and 2-year survival rate (64.9 % versus 43.5 %; p = 0.05).

Conclusions

In metastatic male breast cancer patients, the combined use of gonadotropin-releasing hormone analogues and aromatase inhibitors or antiandrogens seems to be associated with greater efficacy, particularly in terms of survival outcomes, compared with monotherapy. Collectively, these results encourage considering these agents in the metastatic setting.

hMENA(11a) contributes to HER3-mediated resistance to PI3K inhibitors in HER2-overexpressing breast cancer cells

Human Mena (hMENA), an actin regulatory protein of the ENA/VASP family, cooperates with ErbB receptor family signaling in breast cancer. It is overexpressed in high-risk preneoplastic lesions and in primary breast tumors where it correlates with HER2 overexpression and an activated status of AKT and MAPK. The concomitant overexpression of hMENA and HER2 in breast cancer patients is indicative of a worse prognosis. hMENA is expressed along with alternatively expressed isoforms, hMENA(11a) and hMENAΔv6 with opposite functions. A novel role for the epithelial-associated hMENA(11a) isoform in sustaining HER3 activation and pro-survival pathways in HER2-overexpressing breast cancer cells has been identified by reverse phase protein array and validated in vivo in a series of breast cancer tissues. As HER3 activation is crucial in mechanisms of cell resistance to PI3K inhibitors, we explored whether hMENA(11a) is involved in these resistance mechanisms. The specific hMENA(11a) depletion switched off the HER3-related pathway activated by PI3K inhibitors and impaired the nuclear accumulation of HER3 transcription factor FOXO3a induced by PI3K inhibitors, whereas PI3K inhibitors activated hMENA(11a) phosphorylation and affected its localization. At the functional level, we found that hMENA(11a) sustains cell proliferation and survival in response to PI3K inhibitor treatment, whereas hMENA(11a) silencing increases molecules involved in cancer cell apoptosis. As shown in three-dimensional cultures, hMENA(11a) contributes to resistance to PI3K inhibition because its depletion drastically reduced cell viability upon treatment with PI3K inhibitor BEZ235. Altogether, these results indicate that hMENA(11a) in HER2-overexpressing breast cancer cells sustains HER3/AKT axis activation and contributes to HER3-mediated resistance mechanisms to PI3K inhibitors. Thus, hMENA(11a) expression can be proposed as a marker of HER3 activation and resistance to PI3K inhibition therapies, to select patients who may benefit from these combined targeted treatments. hMENA(11a) activity could represent a new target for antiproliferative therapies in breast cancer.

High nuclear level of Vav1 is a positive prognostic factor in early invasive breast tumors: a role in modulating genes related to the efficiency of metastatic process

Vav1 is one of the signalling proteins normally restricted to hematopoietic cells that results ectopically expressed in solid tumors, including breast cancer. By immunohistochemical analysis on TMAs containing invasive breast tumor from patients without lymph node involvement, we have found that Vav1 is expressed in almost all investigated cancers and shows a peculiar localization inside the nucleus of tumor cells. High amounts of nuclear Vav1 are positively correlated with low incidence of relapse, regardless phenotype and molecular subtype of breast neoplasia. In particular, Kaplan-Meier plots showed an elevated risk of distant metastasis in patients with low Vav1 expression compared with patients with high Vav1 expression in their tumors. Experiments performed with breast tumor-derived cells indicated that Vav1 negatively modulates their invasiveness in vitro and their metastatic efficiency in vivo, possibly by affecting the expression of genes involved in invasion and/or metastasis of breast tumors. Since the high heterogeneity of breast tumors makes difficult to predict the evolution of early breast neoplasias, the evaluation of nuclear Vav1 levels may help in the characterization and management of early breast cancer patients. In particular, Vav1 may serve as a prognostic biomarker and a target for new therapies aimed to prevent breast cancer progression.

Cdx2 polymorphism affects the activities of vitamin D receptor in human breast cancer cell lines and human breast carcinomas

Vitamin D plays a role in cancer development and acts through the vitamin D receptor (VDR). It regulates the action of hormone responsive genes and is involved in cell cycle regulation, differentiation and apoptosis. VDR is a critical component of the vitamin D pathway and different common single nucleotide polymorphisms have been identified. Cdx2 VDR polymorphism can play an important role in breast cancer, modulating the activity of VDR. The objective of this study is to assess the relationship between the Cdx2 VDR polymorphism and the activities of VDR in human breast cancer cell lines and carcinomas breast patients. Cdx2 VDR polymorphism and antiproliferative effects of vitamin D treatment were investigated in a panel of estrogen receptor-positive (MCF7 and T-47D) and estrogen receptor-negative (MDA-MB-231, SUM 159PT, SK-BR-3, BT549, MDA-MB-468, HCC1143, BT20 and HCC1954) human breast cancer cell lines. Furthermore, the potential relationship among Cdx2 VDR polymorphism and a number of biomarkers used in clinical management of breast cancer was assessed in an ad hoc set of breast cancer cases. Vitamin D treatment efficacy was found to be strongly dependent on the Cdx2 VDR status in ER-negative breast cancer cell lines tested. In our series of breast cancer cases, the results indicated that patients with variant homozygote AA were associated with bio-pathological characteristics typical of more aggressive tumours, such as ER negative, HER2 positive and G3. Our results may suggest a potential effect of Cdx2 VDR polymorphism on the efficacy of vitamin D treatment in aggressive breast cancer cells (estrogen receptor negative). These results suggest that Cdx2 polymorphism may be a potential biomarker for vitamin D treatment in breast cancer, independently of the VDR receptor expression.

HER2 status determination: analyzing the problems to find the solutions

Misdiagnosis in the evaluation of HER2 status in breast cancer may have consequent negative impact on clinical decision-making. Therefore, it has become ever more important to share procedures and interpretation criteria for HER2 testing among laboratories. Herein, we report an interlaboratory survey among 9 hospitals located in the central-south regions of Italy. The centers sent a series of 36 slides, 4 for each HER2 score, to the revising centers. We found a good concordance in HER2 scoring for 0 and 3+ score, but a very low concordance for 1+ and 2+ scores. To focus on factors that may lead to discordant results, we report 4 cases which summarized the most common source of discrepancy in HER2 testing. This methodological approach will help the individual laboratory to minimize technical variables and to reduce the percentage of erroneous interpretations of HER2 status.