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Triple-negative breast cancer (TNBC) represents 10% of all breast cancers and is a very heterogeneous disease. Globally, women with TNBC have a poor prognosis, and the development of effective targeted therapies remains a real challenge. Patient-derived xenografts (PDX) are clinically relevant models that have emerged as important tools for the analysis of drug activity and predictive biomarker discovery. The purpose of this work was to analyze the molecular heterogeneity of a large panel of TNBC PDX (n = 61) in order to test targeted therapies and identify biomarkers of response. At the gene expression level, TNBC PDX represent all of the various TNBC subtypes identified by the Lehmann classification except for immunomodulatory subtype, which is underrepresented in PDX. NGS and copy number data showed a similar diversity of significantly mutated gene and somatic copy number alteration in PDX and the Cancer Genome Atlas TNBC patients. The genes most commonly altered were TP53 and oncogenes and tumor suppressors of the PI3K/AKT/mTOR and MAPK pathways. PDX showed similar morphology and immunohistochemistry markers to those of the original tumors. Efficacy experiments with PI3K and MAPK inhibitor monotherapy or combination therapy showed an antitumor activity in PDX carrying genomic mutations of PIK3CA and NRAS genes. TNBC PDX reproduce the molecular heterogeneity of TNBC patients. This large collection of PDX is a clinically relevant platform for drug testing, biomarker discovery and translational research., (© 2019 UICC.)

Squamous cell carcinoma of the anal canal (SCCA) is a rare HPV-associated cancer with limited sensitivity to standard chemotherapy. In a phase 2 study, nivolumab, an anti PD-1 immune checkpoint inhibitor, demonstrated significant efficacy as single-agent therapy in metastatic SCCA patients. Nevertheless, imaging assessment by standard RECIST criteria of the efficacy of immune therapy can be difficult in some patients due to tumor immune cell infiltration, and biomarkers of treatment efficacy are needed. We have previously developed a quantitative droplet digital PCR (ddPCR) technique to detect HPV circulating tumor DNA (HPV ctDNA), with excellent sensitivity and specificity. Here, we report, for the first time, the kinetics of HPV ctDNA during therapy in a patient with metastatic SCCA, who obtained sustained partial response to single-agent nivolumab. We observed an early and very significant decrease of HPV ctDNA during therapy from the baseline level of 3713 copies/ml plasma to 564 copies/ml plasma at 4 weeks, and 156 copies/ml at 6 weeks, followed by a plateau. This observation provides proof-of-concept that HPV ctDNA can be used as a noninvasive early dynamic biomarker to monitor the efficacy of new immunotherapy agents., (© 2017 UICC.)

In order to assess the variation in expression of poly(ADP-ribose) polymerase (PARP) family members and the hydrolases that degrade the poly(ADP-ribose) polymers they generate and possible associations with classical pathological parameters, including long-term outcome, the mRNA levels of PARP1, PARP2, PARP3, poly(ADP-ribose) glycohydrolase (PARG) and ADP-ribosylhydrolase 3 (ARH3) were examined using quantitative reverse transcription polymerase chain reaction in 443 unilateral invasive breast cancers and linked to hormonal status, tumor proliferation and clinical outcome. PARP1 mRNA levels were the highest among these five genes in both normal and tumor tissues, with a 2.45-fold higher median level in tumors compared to normal tissues. Tumors (34.1%) showed PARP1 overexpression (>3 fold relative to normal breast tissues) compared to underexpression (<0.33 fold) in only 0.5%. This overexpression was seen in all breast tumor subgroups, with the highest fraction (51%) seen in the HR-positive/ERBB2-positive subgroup and was not highly associated with any other classical predictive factors. No correlation was seen between PARP1 mRNA and PARP-1 protein levels in a subset of 31 tumors. PARP3 was underexpressed in 10.4% of tumors, more frequently in the HR-negative tumors (25.4%) than the HR-positive tumors (5.9%). This PARP3 underexpression was mutually exclusive with a PARP1 overexpression. PARP2 levels were unchanged between normal and tumor tissues and few tumors showed overexpression of PARG (3.8%) or ARH3 (3.4%). Within the subgroup of triple negative tumors, PARG mRNA levels below the median were associated with a higher risk of developing metastases (p = 0.039) raising the possibility this might be marker of clinical outcome., (Copyright © 2013 UICC.)

IBC (inflammatory breast cancer) is a rare but very aggressive form of breast cancer with a particular phenotype. The molecular mechanisms responsible for IBC remain largely unknown. In particular, genetic and epigenetic alterations specific to IBC remain to be identified. MicroRNAs, a class of small noncoding RNAs able to regulate gene expression, are deregulated in breast cancer and may therefore serve as tools for diagnosis and prediction. This study was designed to determine miRNA expression profiling (microRNAome) in IBC. Quantitative RT-PCR was used to determine expression levels of 804 miRNAs in a screening series of 12 IBC compared to 31 non-stage-matched non-IBC and 8 normal breast samples. The differentially expressed miRNAs were then validated in a series of 65 IBC and 95 non-IBC. From a set of 18 miRNAs of interest selected from the screening series, 13 were differentially expressed with statistical significance in the validation series of IBC compared to non-IBC. Among these, a 5-miRNA signature comprising miR-421, miR-486, miR-503, miR-720 and miR-1303 was shown to be predictive for IBC phenotype with an overall accuracy of 89%. Moreover, multivariate analysis showed that this signature was an independent predictor of poor Metastasis-Free Survival in non-IBC patients., (© 2013 UICC.)

The aim of this study was to evaluate the expression levels of microRNAs (miRNAs) in bladder tumors in order to identify miRNAs involved in bladder carcinogenesis with potential prognostic implications. Expression levels of miRNAs were assessed by quantitative real-time RT-PCR in 11 human normal bladder and 166 bladder tumor samples (86 non-muscle-invasive bladder cancer (NMIBC) and 80 muscle-invasive bladder cancer (MIBC)). The expression level of 804 miRNAs was initially measured in a well-defined series of seven NMIBC, MIBC and normal bladder samples (screening set). The most strongly deregulated miRNAs in tumor samples compared to normal bladder tissue were then selected for RT-PCR validation in a well-characterized independent series of 152 bladder tumors (validation set), and in six bladder cancer cell lines. Expression levels of these miRNAs were tested for their association with clinical outcome. A robust group of 15 miRNAs was found to be significantly deregulated in bladder cancer. Except for two miRNAs, miR-146b and miR-9, which were specifically upregulated in MIBC, the majority of miRNAs (n = 13) were deregulated in the same way in the two types of bladder tumors, irrespective of pathological stage : three miRNAs were upregulated (miR-200b, miR-182 and miR-138) and the other 10 miRNAs were downregulated (miR-1, miR-133a, miR-133b, miR-145, miR-143, miR-204, miR-921, miR-1281, miR-199a and miR-199b). A 3-miRNA signature (miR-9, miR-182 and miR-200b) was found to be related to MIBC tumor aggressiveness and was associated with both recurrence-free and overall survival in univariate analysis with a trend to significance in the multivariate analysis (p = 0.05). Our results suggested a promising individual prognostic value of these new markers., (Copyright © 2012 UICC.)

Endocrine therapy resistance is one of the main challenges in the treatment of estrogen receptor positive (ER+) breast cancer patients. This study showed that two ER+ human breast carcinoma cell lines derived from MCF-7 (MVLN cells) that have acquired under OH-Tamoxifen selection two distinct phenotypes of endocrine resistance both displayed constitutive activation of the PI3K/Akt and MAPK pathways. Aberrant expression and activation of the ErbB system (phospho-EGFR, phospho-ErbB2, phospho-ErbB3, over-expression of ErbB4 and over-expression of several ErbB ligands) were also observed in the two resistant cell lines, suggesting the existence of an autocrine loop leading to constitutive activation of MAPK and PI3K/Akt survival pathways. The recent clinical use of specific signal transduction inhibitors is one of the most promising therapeutic approaches in breast cancers. The MEK inhibitor PD98059 and the PI3K inhibitor LY294002 were both able to enhance the cytostatic effect of OH-Tamoxifen or fulvestrant on MVLN sensitive cells. In the two resistant cell lines, inhibition of the MAPK or the PI3K/Akt pathways associated with endocrine therapy was sufficient to reverse OH-Tamoxifen or fulvestrant resistance. Investigating the effect of a combination of both inhibitors on the reversion of OH-Tamoxifen and fulvestrant resistance in the two resistant cell lines suggested that, in clinical practice, a strategy combining the two inhibitors would be the best approach to target the different endocrine resistance phenotypes possibly present in a tumor. In conclusion, the combination of MAPK and PI3K inhibitors represents a promising strategy to overcome endocrine therapy resistance in ER+ breast cancer patients.

Endometrial cancer is well known to be estrogen-dependent. Two estrogen receptor types, ERalpha and ERbeta, are major mediators of a diversity of biologic functions of estrogen and play an important role in estrogen-dependent tissues and cancers. Cloning of ERbeta was followed by the discovery of a variety of its isoforms. Using real-time RT-PCR, the relative expression levels of ERbeta1, ERbeta2 (ERbetacx), ERbeta3, ERbeta4 and ERbeta5 were studied. We observed coexpression of ERbeta isoforms in the endometrium and upregulation of the ERbeta5 transcript in malignant endometrium. We also observed downregulation of ERbeta2Delta5 transcript in neoplastic endometrium, using a semiquantitative method. Our results suggest that analyzing the changes in ERbeta and its isoforms may be important in the diagnosis, prognosis and treatment of endometrial cancer., (Copyright 2004 Wiley-Liss, Inc.)

Inflammatory breast cancer (IBC) is a rare but particularly aggressive form of primary breast cancer. In contrast to noninflammatory breast cancer (non IBC), the molecular alterations underlying IBC are poorly known. We postulated that the kind and frequency of these alterations might differ between IBC and non IBC and account for its particular aggressiveness. We investigated allelic losses associated with primary breast cancer (on chromosome arms 1p, 3p, 6p, 6q, 7q, 8p, 9p, 11p, 11q, 16q, 17p and 17q) by analyzing 71 microsatellite markers in 66 cases of IBC. Loss of heterozygosity (LOH) was frequent, with a mean fractional allelic loss (FAL) index of 52%. Relative to published data on non IBC, allelic loss was particularly frequent at 3p21-p14, 6p, 8p22, 11q, 13q14 and 17q21, suggesting the presence of genes that are markedly altered in IBC. In contrast, the DNA amplification levels of ERBB2, MYC and CCND1, as measured by real-time quantitative PCR, did not differ between IBC and non IBC., (Copyright 2002 Wiley-Liss, Inc.)

EcoRI restriction fragment length polymorphism (RFLP) of the L-myc gene was examined in leukocyte DNAs isolated from 381 breast cancer patients. No differences in the patterns of L-myc RFLP were found between breast cancer patients and healthy individuals. However, among 97 patients who relapsed, a statistical correlation was found between L-myc RFLP and lung metastases (p less than 0.05). These results are in close agreement with previous findings in patients with cancer of the lung, bone or kidney, and suggest that L-myc RFLP may be a useful marker for predicting lung metastasis in some human cancers.