Circulating tumor cell count and thrombosis in metastatic breast cancer

Essentials Tumor cells circulating in blood (CTC) may favor thrombotic events in cancer patients. We assessed the impact of CTC on the risk of thrombosis in metastatic breast cancer. Baseline CTC detection was the only independent factor associated with the risk of thrombosis. CTC detection under therapy may be the hidden link between tumor progression & thrombosis.

SUMMARY

Background Circulating tumor cell (CTC) count is a major prognostic factor in metastatic breast cancer (MBC) and has been reported to be associated with thrombosis in short-term studies on MBC patients. Objective To assess whether CTC detection (CellSearch® ) before first-line chemotherapy impacts the risk of thrombosis throughout the course of MBC. Patients/Methods Among patients included before first-line chemotherapy for MBC in the prospective IC2006-04 CTC detection study (NCT00898014), the electronic medical files of those patients treated at Institut Curie (Paris, France) were searched in silico and manually checked for incident venous or arterial thrombotic events (TE) in the course of MBC. Univariate and multivariate analyses were performed using Cox and Fine-Gray models, adjusted for age and Khorana score. Results/Conclusions With a median follow-up of 64 months (25-81 months), among the 142 patients included, 34 (24%) experienced a TE (incidence rate, 8 TE/100 patient-years). The TE incidence rate was 13 TE/100 patient-years for the 80 patients with ≥ 1 CTC/7.5 mL of blood before initiating first-line chemotherapy, vs. only 4 TE/100 patient-years for the 62 CTC-negative patients. Fine-Gray multivariate analysis (with death as competing event) included age, Khorana score and baseline lactate dehydrogenase and CTC levels: detectable CTC was the only factor significantly associated with an increased risk of TE (sub-distribution hazard ratio [SHR] for patients with [1-4] CTC = 3.1, 95% CI [1.1; 8.6], SHR for patients with ≥ 5 CTC = 1.4, 95% CI [0.5; 4.6]). This study shows that CTC detection before starting first-line chemotherapy is an independent risk factor for TE in MBC patients.

DNA replication-coupled histone modification maintains Polycomb gene silencing in plants

Propagation of patterns of gene expression through the cell cycle requires prompt restoration of epigenetic marks after the twofold dilution caused by DNA replication. Here we show that the transcriptional repressive mark H3K27me3 (histone H3 lysine 27 trimethylation) is restored in replicating plant cells through DNA replication-coupled modification of histone variant H3.1. Plants evolved a mechanism for efficient K27 trimethylation on H3.1, which is essential for inheritance of the silencing memory from mother to daughter cells. We illustrate how this mechanism establishes H3K27me3-mediated silencing during the developmental transition to flowering. Our study reveals a mechanism responsible for transmission of H3K27me3 in plant cells through cell divisions, enabling H3K27me3 to function as an epigenetic mark.

Magnetocardiography measurements with 4He vector optically pumped magnetometers at room temperature

In this paper, we present a proof of concept study which demonstrates for the first time the possibility of recording magnetocardiography (MCG) signals with ⁴He vector optically pumped magnetometers (OPM) operated in a gradiometer mode. Resulting from a compromise between sensitivity, size and operability in a clinical environment, the developed magnetometers are based on the parametric resonance of helium in a zero magnetic field. Sensors are operated at room temperature and provide a tri-axis vector measurement of the magnetic field. Measured sensitivity is around 210 f T (√Hz)^-1 in the bandwidth (2 Hz; 300 Hz). MCG signals from a phantom and two healthy subjects are successfully recorded. Human MCG data obtained with the OPMs are compared to reference electrocardiogram recordings: similar heart rates, shapes of the main patterns of the cardiac cycle (P/T waves, QRS complex) and QRS widths are obtained with both techniques.

Deep hypothermia therapy attenuates LPS-induced microglia neuroinflammation via the STAT3 pathway

Deep hypothermia therapy (HT) is a standard method for neuroprotection during complex pediatric cardiac surgery involving extracorporeal circulation and deep hypothermic cardiac arrest. The procedure, however, can provoke systemic inflammatory response syndrome (SIRS), one of the most severe side effects associated with pediatric cardiac surgery. To date, the cellular inflammatory mechanisms induced by deep HT remain to be elucidated. Therefore, we investigated the effects of deep HT (17°C) and rewarming on the inflammatory response in lipopolysaccharide (LPS) stimulated BV-2 murine microglia. Additionally, we also investigated the application of Stattic, a signal transducer and activator of transcription 3 (STAT3) activation inhibitor, as an alternative to physical cooling to attenuate the LPS-induced inflammatory response. Deep HT had no cytotoxic effect but attenuated microglia migration. IκBα degradation was delayed by deep HT resulting in the attenuation of pNF-κB p65 migration into the nucleus and significant decreases in pro-inflammatory IL-6, TNF-α, and MCP-1 expressions and secretions, as well as decreased anti-inflammatory IL-10 and SOCS3 expressions. Additionally, pStat3 was significantly down regulated under deep hypothermic conditions, also corresponding with the significant reduction in IL-6 and TNF-α expressions. Similar to the effects of HT, the application of Stattic under normothermic conditions resulted in significantly reduced IL-6 and TNF-α expressions. Moreover, attenuation of the inflammatory response resulted in decreased apoptosis in a direct co-culture of microglia and neurons. HT reduces the inflammatory response in LPS-stimulated BV-2 microglial cells, alluding to a possible mechanism of therapeutic hypothermia-induced neuroprotection. In the future, attenuating the phospho-STAT3 pathway may lead to the development of a neuroprotectant with greater clinical efficacy.

The histone H3 variant H3.3 regulates gene body DNA methylation in Arabidopsis thaliana

BACKGROUND

Gene bodies of vertebrates and flowering plants are occupied by the histone variant H3.3 and DNA methylation. The origin and significance of these profiles remain largely unknown. DNA methylation and H3.3 enrichment profiles over gene bodies are correlated and both have a similar dependence on gene transcription levels. This suggests a mechanistic link between H3.3 and gene body methylation.

RESULTS

We engineered an H3.3 knockdown in Arabidopsis thaliana and observed transcription reduction that predominantly affects genes responsive to environmental cues. When H3.3 levels are reduced, gene bodies show a loss of DNA methylation correlated with transcription levels. To study the origin of changes in DNA methylation profiles when H3.3 levels are reduced, we examined genome-wide distributions of several histone H3 marks, H2A.Z, and linker histone H1. We report that in the absence of H3.3, H1 distribution increases in gene bodies in a transcription-dependent manner.

CONCLUSIONS

We propose that H3.3 prevents recruitment of H1, inhibiting H1's promotion of chromatin folding that restricts access to DNA methyltransferases responsible for gene body methylation. Thus, gene body methylation is likely shaped by H3.3 dynamics in conjunction with transcriptional activity.

[Stable disease or complete response? : A critical evaluation of the radiologic response to immune checkpoint blockade in advanced melanoma]

BACKGROUND

Rating the response of melanoma to immune checkpoint blockade (ICB) by conventional CT proves to be difficult, since response patterns and kinetics differ from the classical responses seen with other therapies. Hence, immune-related response criteria were developed. However, they are mainly based on the alteration of the diameter of lesions over time but do not include metabolic activity.

OBJECTIVE

The aim of this study was to search for additional criteria to improve the interpretation of the radiologic images of patients with metastatic melanoma after ICB.

MATERIALS AND METHODS

We retrospectively analysed 7 patients with metastatic melanoma over a period of 13-41 months after treatment with ICB using contrast enhanced CT scans from the neck region to the lower abdomen and compared the results in the follow ups with ¹⁸F-FDG PET/CT.

RESULTS

Metastatic lesions in 5 of 7 patients rated as stable disease (SD) in CT staging showed no metabolic activity in ¹⁸F-FDG PET/CT. The size of these lesions did not increase or show metabolic activity in the further follow-up, even after discontinuation of ICB. In contrast, tumor lesions in the other 2 patients rated as SD in CT staging showed metabolic activity in ¹⁸F-FDG PET/CT. These tumor lesions expanded significantly in the further course of the disease.

CONCLUSION

In addition to the size of a tumor lesion, its metabolic activity adds important information regarding treatment response. Thus, we propose that the metabolic activity assessed with ¹⁸F-FDG-PET/CT should be included in the immune response criteria. No FDG uptake in a lesion should be rated as inactive tumor rather than SD and further treatment may not be required.

Compartmentalization of DNA Damage Response between Heterochromatin and Euchromatin Is Mediated by Distinct H2A Histone Variants

DNA double-strand break (DSB) repair depends on the ataxia telangiectasia mutated (ATM) kinase that phosphorylates the conserved C-terminal SQ motif present in the histone variant H2A.X [1-7]. In constitutive heterochromatin of mammals, DSB repair is delayed and relies on phosphorylation of the proteins HP1 and KAP1 by ATM [2, 8-14]. However, KAP1 is not conserved in plants and the HP1-related protein Like-HP1 (LHP1) is not localized at constitutive heterochromatin [15], suggesting that in plants, alternative mechanisms could be responsible for repair of DSBs in heterochromatin. In Arabidopsis, constitutive heterochromatin is marked by H3K9 methylation and the plant-specific histone variants H2A.W, which are distinguished by their C-terminal motif KSPKK and required for heterochromatin compaction [16-18]. We report that the Arabidopsis histone variant H2A.W.7 is confined to heterochromatin and carries a SQ motif that is phosphorylated by ATM. In response to DNA damage, phosphorylation of H2A.W.7 takes place in heterochromatin, while H2A.X phosphorylation takes place primarily in euchromatin. We propose that H2A.W.7 evolved in addition to H2A.X to facilitate DNA damage response in highly condensed heterochromatin, thus playing a role similar to KAP1 and HP1 phosphorylation in mammals. These data support the idea of the functional diversification of histone variants and their role in spatial compartmentalization of chromatin-related functions in eukaryotes.

Abstract P1-01-02: Circulating tumor cells (CTC) and endothelial cells (CEC) prognostic value in HER2 negative metastatic breast cancer patients treated with first line weekly paclitaxel and bevacizumab: First results of a prospective cohort from the French Breast Cancer InterGroup Unicancer (UCBG): COMET study

Background: increased levels of circulating tumor cells (CTC) are associated with worse progression-free survival (PFS) and overall survival (OS) in patients (pts) with metastatic breast cancer (MBC). It has been hypothesized that bevacizumab could modify CTC prognostic value. CEC variations to predict benefit of anti-angiogenic treatment is still controversial. Predictive markers for response to bevacizumab combined to chemotherapy in MBC remains a clinical unmet need.

Patients & methods: The French cohort COMET is a prospective study including first line HER2 negative patients (pts) receiving weekly paclitaxel and bevacizumab according to EMA approved combination. The aim of this cohort is to evaluate clinical, biological and radiological parameters associated with pts outcome (CTC, CEC, serum markers, ctDNA, pharmacogenomic polymorphisms, metabolomic parameters, visceral fat assessed by initial CTscan, serum estradiol level, and quality of life). We present here the first planned analysis on 203 pts evaluated for CTC and CEC using the FDA cleared CellSearch method.

Results: For CTC substudy, 211 patients were included from 09/2012 to 5/2014. Median follow-up is 24 months. Median PFS was 10 months (CI95 9-12) and response rate was 57%. Median OS was not reached. 203 patients were evaluable for both CTC and CEC at baseline and first day of second cycle of CT (D1C2). At baseline, 97/203 (48%) pts had ≥ 5 CTC (median 4 (range 0-30,000). Median number CEC was 21 (0-2231) at baseline and 22 (1-881) at D1C2. LDH, CEA, CA15.3 and CYFRA 21 were above normal at baseline in 44%, 46%, 73% and 71% of the cases respectively. CTC level was not correlated with any patients' characteristics except a number of metastatic site >3. After one cycle of chemotherapy (D1C2) 37 pts (22%) had still ≥ 5 CTC: 36 pts with initial high level and only one patient with low CTC at baseline had increased CTC above 5. Prognostic factors for PFS at univariate analysis were visceral disease, number of metastatic sites (> 3), triple negative status, LDH, CTC level at baseline and CTC level after one cycle of chemotherapy (D1C2). None of serum marker nor CEC level at baseline or any variations had prognostic value. In multivariate analysis for PFS, CTC level after one cyle of chemotherapy predicts poor outcome

Table 1 Multivariate analysis for PFSPts' characteristicsnRRCI 95%p-valueNumber of metastatic sites    <3 sites971  >=3 sites1001.65[1.13 ; 2.41]0.010CTC D1C2    < 51321  >= 5372.17[1.43 ; 3.29]<0.001Hormonal status    Luminal (HR+)1531  Triple negative372.86[1.85 ; 4.54]<0.001

Conclusion: We confirm in a large prospective series the lack of clinical validity of CEC to predict response to an antiangiogenic based treatment in MBC. A persistent elevated level of CTC after just one cycle of chemotherapy is a very strong and independent marker of poor outcome in a homogeneously bevacizumab-treated cohort of MBC patients. This marker could be used to stopped earlier an inefficient and costly treatment.

Citation Format: Pierga J-Y, Tredant O, Chevrier M, Dubot C, Lorgis V, Romieu G, Goncalves A, Debled M, Levy C, Ferrero J-M, Jouannaud C, Luporsi E, Mouret-Reynier M-A, Dalenc F, Berger F, Lemonnier J, Proudhon C, Bidard F-C. Circulating tumor cells (CTC) and endothelial cells (CEC) prognostic value in HER2 negative metastatic breast cancer patients treated with first line weekly paclitaxel and bevacizumab: First results of a prospective cohort from the French Breast Cancer InterGroup Unicancer (UCBG): COMET study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-01-02.

Abstract P1-03-05: A comprehensive molecular analysis of medullary breast carcinoma: A model of immunomodulatory triple negative breast cancer subtype

Medullary breast carcinoma (MBC) is a rare subtype of triple negative breast cancer (TNBC)with specific genomic features within the spectrum of basal-like carcinoma. The frequent association between BRCA constitutive mutation and MBC phenotype has been reported previously. In this study including 19 MBC and 36 non-MMB basal-like carcinoma (BLC), we refine the genomic and transcriptomic knowledge about this entity. Using pan genomic Affymetrix genome-wide human SNP6.0 array, we show that i/ MBC harbour more copy number alterations and losses of heterozygocity than BLC and that ii/ the high frequency of BRCAness genomic trait among MBC. Unsupervised and supervised analysis of GeneChip Uman Genome U133 Plus 2.0 Array transcriptomic generated data confirmed that MBC clearly differ from BLC in terms of gene expression level, with 92 genes overexpressed and 154 genes underexpressed in MBC over BLC. Immune response and inflammatory response are the most differentially represented pathways in MBC over BLC. Pro apoptotic gene BCLG is by far the more overexpressed gene in MBC. A validation study conducted with RT-QPCR among 526 breast tumors form all molecular subtype confirmed the specificity of BCLG overexpression in MBC, which was confirmed at protein level using immunohistochemisytry. Moreover, we show that a vast majority of MBC belong o the immunomodulatory TNBC subtype according to Lehman et al. Finally, we confirm the better prognosis of MBC toward BLC. Our observations epitomize the importance of developing DNA repair targeting drugs and immunotherapy based trials in order to improve the outcome of such a specific entity.

Citation Format: Romero P, Deniziaut G, Benhamo V, Fuhrmann L, Berger F, Bhalshankar J, Gruel N, MacGrogan G, Popova T, Manié E, Stern M-H, Stoppa-Lyonnet D, Rouzier R, Delattre O, Bieche I, Vincent-Salomon A. A comprehensive molecular analysis of medullary breast carcinoma: A model of immunomodulatory triple negative breast cancer subtype [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-03-05.