Frédérique Berger

Asf1b, the necessary Asf1 isoform for proliferation, is predictive of outcome in breast cancer

Mammalian cells possess two isoforms of the histone H3–H4 chaperone anti‐silencing function 1 (Asf1), Asf1a and Asf1b. However to date, whether they have individual physiological roles has remained elusive. Here, we aim to elucidate the functional importance of Asf1 isoforms concerning both basic and applied aspects. First, we reveal a specific proliferation‐dependent expression of human Asf1b unparalleled by Asf1a. Strikingly, in cultured cells, both mRNA and protein corresponding to Asf1b decrease upon cell cycle exit. Depletion of Asf1b severely compromises proliferation, leads to aberrant nuclear structures and a distinct transcriptional signature. Second, a major physiological implication is found in the applied context of tissue samples derived from early stage breast tumours in which we examined Asf1a/b levels. We reveal that overexpression of Asf1b mRNA correlate with clinical data and disease outcome. Together, our results highlight a distribution of tasks between the distinct Asf1 isoforms, which emphasizes a specialized function of Asf1b required for proliferation capacity. We discuss the implications of these results for breast cancer diagnosis and prognosis.

Early assessment with 18F-fluorodeoxyglucose positron emission tomography/computed tomography can help predict the outcome of neoadjuvant chemotherapy in triple negative breast cancer

BACKGROUND In patients with triple-negative breast cancer (TNBC), pathology complete response (pCR) to neoadjuvant chemotherapy (NAC) is associated with improved prognosis. This prospective study was designed and powered to investigate the ability of interim (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)FDG-PET/CT) to predict pathology outcomes to NAC early during treatment. PATIENTS AND METHODS Consecutive TNBC women underwent (18)FDG-PET/CT at baseline and after two courses of NAC. Maximum standardised uptake value (SUV(max)) in the primary tumour and lymph nodes at each examination and the evolution (ΔSUV(max)) between the two scans were measured. NAC was continued irrespective of PET results. Correlations between PET parameters and pathology response, and between PET parameters and event-free survival (EFS), were examined. RESULTS Fifty patients without distant metastases were enroled. At completion of NAC, surgery showed pCR in 19 patients, while 31 had residual tumour. Mean follow-up was 30.3 months. Thirteen patients, all with residual tumour, experienced relapse. Of all assessed clinical, biological and PET parameters, ΔSUV(max) in the primary tumour was the most predictive of pathology results (p<0.0001; Mann-Whitney-U test) and EFS (p=0.02; log rank test). A threshold of 42% decrease in SUV was identified because it offered the best accuracy in predicting EFS. There were 32 metabolic responders (⩾ 42% decrease in SUV(max)) and 18 non-responders. Within responders, the pCR rate was 59% and the 3-year EFS 77.5%. In non-responders, the pCR rate was 0% and the 3-year EFS 47.1%. CONCLUSION Interim (18)FDG can early predict the inefficacy of NAC in TNBC patients. It shows promise as a potential contributory biomarker in these patients.

The histone chaperone HJURP is a new independent prognostic marker for luminal A breast carcinoma

Breast cancer is a heterogeneous disease with different molecular subtypes that have varying responses to therapy. An ongoing challenge in breast cancer research is to distinguish high‐risk patients from good prognosis patients. This is particularly difficult in the low‐grade, ER‐positive luminal A tumors, where robust diagnostic tools to aid clinical treatment decisions are lacking. Recent data implicating chromatin regulators in cancer initiation and progression offers a promising avenue to develop new tools to help guide clinical decisions.

Circulating tumor cell thresholds and survival scores in advanced metastatic breast cancer: The observational step of the CirCe01 phase III trial

The clinical validity of circulating tumor cell (CTC) count changes during chemotherapy in metastatic breast cancer patients has been validated, but its clinical utility remains to be demonstrated. We report here the non-randomized run-in phase of the CirCe01 trial which was designed to evaluate CTC changes and thresholds to other palliative prognostic scores and establish CTC thresholds to be used in the randomized part of the study. CTC count (CellSearch®) and other prognostic parameters (serum albumin level, lymphocyte level, LDH level, prognostic inflammatory and nutritional index (PINI) and Barbots score) were assessed in 56 metastatic breast cancer patients before the first cycle of third line chemotherapy. Early changes of CTC count were correlated with treatment outcome. Independent prognostic markers in multivariate analysis were: low serum albumin (HR = 11.1), poor performance status (HR = 3.8), ≥5 CTC/7.5 ml (HR = 3.8) and triple negative subtype (HER2+ and hormone positive vs triple negative: both HR = 0.2). Among patients with ≥5 CTC/7.5 ml at baseline, a composite criteria (<5 CTC/7.5 ml or relative decrease ≥-70% of the baseline CTC count) showed better prognostication for PFS (p=0.002).

Diagnostic and prognostic information obtained on fine-needle aspirates of primary neuroblastic tumors: Proposal for a cytology prognostic score.

The use of cytological material for diagnosis and prognosis in patients with neuroblastic tumors is poorly described in the literature.

Identification of new candidate therapeutic target genes in head and neck squamous cell carcinomas

Background We aimed at identifying druggable molecular alterations at the RNA level from untreated HNSCC patients, and assessing their prognostic significance. Methods We retrieved 96 HNSCC patients who underwent primary surgery. Real-time quantitative RT-PCR was used to analyze a panel of 42 genes coding for major druggable proteins. Univariate and multivariate analyses were performed to assess the prognostic significance of overexpressed genes. Results Median age was 56 years [35–78]. Most of patients were men (80%) with a history of alcohol (70.4%) and/or tobacco consumption (72.5%). Twelve patients (12%) were HPV-positive. Most significantly overexpressed genes involved cell cycle regulation (CCND1 [27%], CDK6 [21%]), tyrosine kinase receptors (MET [18%], EGFR [14%]), angiogenesis (PGF [301%], VEGFA [14%]), and immune system (PDL1/CD274 [28%]). PIK3CA expression was an independent prognostic marker, associated with shorter disease-free survival. Conclusions We identified druggable overexpressed genes associated with a poor outcome that might be of interest for personalizing treatment of HNSCC patients.

Predictive gene signature of response to the anti-TweakR mAb PDL192 in patient-derived breast cancer xenografts.

Purpose (1) To determine TweakR expression in human breast cancers (BC), (2) evaluate the antitumor effect of the anti-TweakR antibody PDL192, used alone or after chemotherapy-induced complete remission (CR), on patient-derived BC xenografts (PDX) and (3) define predictive markers of response. Experimental Design TweakR expression was analyzed by IHC on patients and PDXs BC samples. In vivo antitumor effect of PDL192 was evaluated on eight TweakR-positive BC PDXs alone or after complete remission induced by a combination of doxorubicin and cyclophosphamide. Using both responding and resistant PDX tumors after PDL192 administration, RT-QPCR were performed on a wide list of selected candidate genes to identify predictive markers of response. Results TweakR protein was expressed in about half of human BC samples. In vivo PDL192 treatment had significantly anti-tumor activity in 4 of 8 TweakR-positive BC PDXs, but no correlation between the expression level of the Tweak receptor and response to therapy was observed. PDL192 also significantly delayed tumor relapse after CR. Finally, an 8 gene signature was defined from sensitive and resistant PDXs. Conclusions PDL192 was highly efficient in some BC PDXs. We found 8 genes that were differentially expressed in responding and resistant tumors and could constitute a gene expression signature which would need to be extended to other xenograft models for confirmation. These data confirm the therapeutic potential of TweakR targeting in BC and the possibility of prospectively selecting patients who might benefit from therapy.

Ligand-receptor dissociated expression explains high TSLP without prognostic impact in human primary head and neck squamous cell carcinoma.

ABSTRACT Thymic stromal lymphopoietin (TSLP) is an interleukin (IL)-7-like cytokine expressed by epithelial cells during allergic inflammation, and activating dendritic cells (DC). Its expression and functional role in cancer remain controversial. We conducted retrospective (n = 89), and prospective studies including patients with untreated primary head and neck squamous cell carcinoma (HNSCC). We found that TSLP was overexpressed by HNSCC tumor cells, and associated with a highly differentiated status. However, no significant difference in overall and recurrence-free survival was found between patients bearing a tumor with high and low TSLP levels, respectively. Surprisingly, there was no significant association between the levels of TSLP expression, and the number of tumor-infiltrating mature DCLAMP+ DC. In order to explain the apparent lack of TSLP-induced DC activation, we performed phenotypic and functional experiments on freshly resected tumors. Tumor-infiltrating immune cells, including DC, did not express the TSLP receptor heterodimer (TSLPR chain, IL-7Ralpha chain). Furthermore, freshly sorted blood CD11c+ DC from healthy donors cultured with tumor-conditioned supernatant exhibited an activated profile, but this was not affected by an anti-TSLP blocking antibody, suggesting a DC activation pathway independent of tumor-derived TSLP. Overall, our results demonstrate that TSLP is overexpressed in HNSCC but its function is hampered by the lack of TSLPR-expressing cells in the tumor microenvironment. Such a dissociated ligand–receptor expression may impact intercellular communication in other immune activation pathways, and tumor types.

RalB directly triggers invasion downstream Ras by mobilizing the Wave complex

The two Ral GTPases, RalA and RalB, have crucial roles downstream Ras oncoproteins in human cancers; in particular, RalB is involved in invasion and metastasis. However, therapies targeting Ral signalling are not available yet. By a novel optogenetic approach, we found that light-controlled activation of Ral at plasma-membrane promotes the recruitment of the Wave Regulatory Complex (WRC) via its effector exocyst, with consequent induction of protrusions and invasion. We show that active Ras signals to RalB via two RalGEFs (Guanine nucleotide Exchange Factors), RGL1 and RGL2, to foster invasiveness; RalB contribution appears to be more important than that of MAPK and PI3K pathways. Moreover, on the clinical side, we uncovered a potential role of RalB in human breast cancers by determining that RalB expression at protein level increases in a manner consistent with progression toward metastasis. This work highlights the Ras-RGL1/2-RalB-exocyst-WRC axis as appealing target for novel anticancer strategies.

Abstract P4-09-02: Disseminated tumor cells as predictive factor of benefit of lymph node irradiation to prevent loco-regional relapse

Background: Early stage breast cancer patients with micrometastatic spread (cM0(i+) per the 2010 TNM staging), detected either in the bone marrow (disseminated tumor cells, DTC) or in the blood (circulating tumor cells, CTC) are at higher risk of distant relapse and death. Loco-regional relapses were also more frequently observed in patients with DTC and, recently, with CTC (IMENEO study, Bidard et al , SABCS 2016). In that context, we analyzed whether DTC detection would be a predictive factor for the benefit of comprehensive loco-regional irradiation. Methods: Patients with localized breast cancer were eligible for this IRB-approved prospective cohort after informed written consent. DTC status was prospectively assessed by trained pathologists after immunocytostaining following ISHAGE criteria, at time of surgery or prior to any primary systemic therapy. Irradiation volumes (breast or chest wall +/- regional lymph nodes) were defined per standard of care. Locoregional relapse was defined as documented ipsilateral invasive relapse occurring in the breast, chest wall and/or in regional lymph nodes, prior to any distant metastatic relapse. Locoregional relapse-free interval (LRFI) was defined as the time elapsed between breast surgery and locoregional relapse. Cumulative incidence rates and hazard ratio were obtained using both Cox and Fine-Gray models, taking into account metastatic relapse and death as competitive events. Interaction tests were performed to confirm the predictive value of DTC status in a multivariate analysis. Results: From 11.1998 to 09.2005, a total of 620 patients with non-metastatic breast cancer were included in this prospective cohort. Median FU was 11.7 years. Overall, 94 patients (15.1%) were DTC-positive and 50 patients (8.1%) experienced a locoregional relapse during follow-up. DTC detection was significantly associated with shorter LRFI in univariate and multivariate analyses (Cox, HR=2.6 [1.4;4.8], p=0.004 ; Fine-Gray, HR=1.76 [1.04;3.0], p=0.04). In the multivariate subgroup analysis, locoregional lymph node irradiation was associated with a longer LRFI for DTC-positive patients, but not for DTC-negative patients (interaction test in multivariate analysis: p=0.03). Similar results were obtained when taking locoregional relapses synchronous with distant metastatic disease into account (interaction test: p=0.02). Importantly, the predictive value of DTC status for the benefit of locoregional irradiation was independent of other clinical and pathological characteristics, including locoregional nodal (pN) status. Conclusion: This long term analysis confirms the independent long-term prognostic value of DTC on locoregional relapses. Moreover, the finding that cM0(i+) status is a predictive marker for the efficacy of locoregional lymph node irradiation promises a new opportunity to better tailor adjuvant radiation therapy in early stage breast cancer patients. Citation Format: Bidard F-C, Mignot F, Poortmans P, Dureau S, Berger F, Loirat D, Proudhon C, Vincent-Salomon A, Pierga J-Y, Kirova Y. Disseminated tumor cells as predictive factor of benefit of lymph node irradiation to prevent loco-regional relapse [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-09-02.