P10.17.B Androgen receptor signalling has independent prognostic value and is associated with resistance to temozolomide and tumour growth in glioblastoma

Background

The spectrum of sex differences in glioblastoma (GBM) is a rising topic. GBM is more frequent (sex ratio M:F=1.6) and seem to have worse prognosis in males (M) compared to females. Androgen receptor (AR) is expressed in GBM but its role in GBM biology and clinics is not yet fully understood.

Material and Methods

We have selected from our tumour tissue bank: (i) GBM samples with clinical, pathological and molecular annotations and (ii) GBM-patient derived cell lines -GBM-PDCL- with transcriptomic profiling and available tissue from parental tumours.AR expression was investigated using multiplex IHC Opal stained-FFPE sections. Sensitivity of PDCL to hormonotherapy (dihydrotestosterone or enzalutamide EZT) alone or combined with temozolomide (TMZ) was tested using WST1 viability assay. Response to drugs were correlated to AR expression (high: log2 [FPKM] >2 or low: log2 [FPKM] <2). PDCLs dihydrotestosterone secretion was examined by ELISA in both supernatants and cell lysates.

Results

In our cohort of 1188 IDH muted GBM patients, the median follow-up was 27.7 (25.8-31.3). The sex ratio M:F was 1.68 and the median age at diagnosis was 57 years [18-69]. Compared to males, females have better prognosis with a median overall survival of 26.1 months vs 20.8 months (p<0.0001). In multivariate analysis, male gender was an independent prognostic factor with a HR of 1.43 CI95%(1.21-1.69) (p<0.0001) adjusted on age, MGMT status and Karnofsky indice . Although interaction between age and sex was not significant (p = 0.854), HR of gender varied through age category 1.53 CI95%( 1.01-2.33 ), 1.51 CI95%( 0.888-2.55 ) and 1.38 CI95%( 0.857-2.21) for males <45 years, between 46-55 years and > 55 years respectively. In GBM tumours, AR staining was positive in 5- 30% tumour cells. After 72h exposure to 10nM dihydrotestosterone, ARhigh GBM-PDCLs exhibit AR nuclear translocation and c-myc expression upregulation, suggesting functional activation of the receptor. AR pharmacological blockade increased temozolomide sensitivity in ARhigh GBM-PDCLs regardless of the patient’s sex. Moreover, ARhigh PDCLs secreted DHT, suggesting autocrine and paracrine AR stimulation in tumour microenvironment.

Conclusion

Our study highlights the independent prognostic significance of sex in GBM patients, where males exhibit a worse prognosis. In GBM-PDCL, we show that androgen receptor is (i) functional in vitro and (ii) associated with resistance to temozolomide. Further studies are needed to investigate the role of AR in tumour tissue microenvironment.

[Status of experiments conducted since 2018 and the place of nurses]

Four years after the launch of Article 51, more than 1,000 projects have been submitted. Among them, 118 experiments have been authorized, enabling the treatment of one million patients throughout France. These experiments are very diverse and cover many of the issues facing our healthcare system. Nurses play a central role, combining care, coordination, specialized care and access to new missions.

[Experiments to renew the organization of care]

While the need to test new ways of organizing our healthcare system has long been recognized, successive initiatives have not always been up to the challenge. Drawing lessons from past experiences, as well as foreign examples, Article 51 of the Social Security Financing Act for 2018 created a new framework for innovative health experiments. Actors in the field now have the opportunity to develop innovative projects while relying on a support and evaluation system for the duration of their trials, according to a logic of co-construction between all stakeholders.

The French innovation funding programme (Article 51)

The “art 51” of the social security financing act was launched in 2018 and created an experimental framework to test a programme for healthcare delivery and payment innovation. Its aim is to fund projects that promote coordination, group practices, integration of care, through adequate payment mechanisms. Projects emerge from the field, identifying unmet needs and proposing innovative health care organisations and payment schemes. This presentation will provide insights into this new experience, into the obstacles and the lessons learned.

A7 DEVELOPING NEW TOOLS TO IDENTIFY NOVELS TARGETS TO OVERCOME TREATMENT RESISTANCE IN ESOPHAGEAL CANCER

Background

In Canada, patients with esophageal cancer have the 2nd worst 5-year survival rate (14%). Esophageal squamous cell carcinoma (ESCC) is the most common esophageal cancer type worldwide. Its high mortality rate is partly due to the treatment resistance acquired by patients, which has mostly been attributed to the presence of cancer stem cells (CSCs). Therefore, targeting CSCs is a promising strategy to improve treatment and survival of ESCC patients. CSCs are a subpopulation of tumor cells presenting high self-renewal and multipotent capacities, and therefore largely contribute to tumor heterogeneity in addition to treatment resistance.

Aims

In this study, we aim to establish human ESCC cell lines resistant to radiotherapy (TE15RR), chemotherapy (TE15CR) and both (TE15RCR), and study the relationship between resistance acquisition and CSC properties;

Methods

To do so, we exposed human ESCC cell line TE15 to chronic doses of radiotherapy (2 Gy/week for a total dose of 60 Gy) and/or increasing doses of chemotherapy (5-FU (1, 2, 5, 10 and 15mM)). We harvested samples at different time points to fully investigate resistance acquisition process. Then, we further validated resistance and properties of the resistant TE15 cell lines.

Results

We confirmed that TE15RR cells are less susceptible to radiation than control cells and showed that they are more proliferative at baseline using MTT assays. Moreover, we demonstrated that TE15RR cells comprise a higher proportion of CD24high/CD44high CSC population using flow cytometry. We also found that they express higher levels of ALDH1, another well-known CSC marker, by qPCR and Western Blot. Our preliminary observations also suggest a higher invasive phenotype in TE15RR cells in limited dilution spheroid assay than in control cells supporting that TE15RR cells display CSC-like properties. TE15CR and TE15RCR cell lines were validated using similar approaches. Finally, mass spectrometry was performed to compare the proteomic profile of the resistant cell lines to the control cell line in order to identify key players in treatment resistance acquisition.

Conclusions

Brief, we developed radioresistant, chemoresistant and radiochemoresistant human ESCC cell lines and demonstrated that resistance acquisition correlates with CSC enrichment. Mass spectrophotometry revealed significant proteomic differences between resistant and control cell lines, which should lead to the identification of novel targets to overcome resistance in ESCC patients.

Funding Agencies

Canada research chair TIER 2

Use of the headache impact test (HIT-6) in general practice: relationship with quality of life and severity

To assess the global impact of episodic headaches in patients consulting general practitioners (GPs) using the Headache Impact Test (HIT-6) questionnaire, and to compare this with measures of headache severity and quality of life. A total of 2802 patients consulting 349 GPs participated to this cross-sectional study. Data were collected on headache severity using the Migraine Severity (MIGSEV) scale, headache impact with the HIT-6 and quality of life with the Qualité de Vie et Migraine (QVM) questionnaire. Diagnosis was assigned retrospectively according to the International Headache Society criteria. The association between the HIT-6 scale and the other scales was determined from a Pearson's chi-square test, an analysis of variance and Spearman correlation coefficients. Patients (2537) provided exploitable data. Six percent of the sample had little impact, 14% moderate, 14% substantial and 66% severe impact. The HIT-6 scores were significantly different between diagnostic groups, being highest in the migraine group. The HIT-6 score were well correlated with headache severity and QVM score. The HIT-6 scale correlates, across different diagnostic groups of headache, with both headache severity and with quality of life.

[Characteristics and influence of different clinical forms on the development and prognosis of carotid sinus syndrome. Apropos of 215 cases]

The carotid sinus syndrome is a well-known cause of syncope: the cardio-inhibitory forms are the easiest to diagnose and probably the easiest to treat. However, the vasodepressive forms are as common but their outcome is mainly unknown. Eight hundred and fifty-three patients underwent endocavitary electrophysiological studies with invasive blood pressure measurement for unexplained syncope between October 1984 and January 1990. A carotid sinus syndrome was diagnosed in 215 cases. Fifty-two patients (24.2%) had a cardio-inhibitory form (ventricular standstill > or = 3 s during carotid sinus massage), 40 (18.6%) had a pure vasodepressive form (isolated fall of systolic blood pressure > 50 mmHg during massage) and 123 patients (57.2%) had a mixed form. The average age was 74.1 +/- 9.7 years with no difference between the different forms. A number of parameters was different on the cardio-inhibitory and vasodepressive forms: the number of men (75.6 vas 24.4%; p < 0.05) and the number of syncopes (83.3 vs 60%; p < 0.02) were greater in the cardio-inhibitory form; the vasodepressive forms were more often associated with a history of transient ischaemic attacks (15 vs 0%), a poor cardiovascular status (hypertension: 47.5 vs 15.7%; p < 0.01), coronary artery disease (47.5 vs 25.5%; p < 0.05), cardiac failure (27.5 vs 11.7%; p < 0.05), induction of sustained supraventricular tachycardia (50 vs 23.5%; p < 0.05) and a greater pacemaker effect (53.6 vs 34.8 mmHg; p < 0.01); of the 191 patients (84.9% of the population) followed up for an average of 21.2 months, 168 received treatment: implantation of a cardiac pacemaker in 108 patients, reduction of antihypertensive and/or potentially bradycardia-inducing drugs in 30 patients, prescription of antiarrhythmic therapy, in 30 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Symptomatic sinus dysfunction. A new use of electrophysiology]

The authors undertook a prospective electrophysiological study of 950 patients: 53 subjects considered to be "controls" since they were free of any history of syncope or faintness were identified, as well as 39 symptomatic subjects with a strong suspicion of sinus dysfunction, since no other detectable cause of fainting episodes was found by extracardiac investigation, 24 hour ECG nor electrophysiology. Following the creation of a computerised tool enabling not only the entry of indirect tests, processing, averaging of results, printing and memorization, but also assistance in interpretation, several electrophysiological parameters were used: heart rate and existence of sinus arrhythmia, Strauss tests with adjusted data or not, effective nodal refractory period, Guize, Narula and Mandel tests, and an atropine (0.03 mg/kg) test which was performed only in the symptomatic group. These tests were studied by single-variate and correlative analysis to define their normal ranges, their critical values and their dependence or independence. The performance of each test (i.e. its efficiency, and the specificity and sensitivity of each critical value) was measured. Tests found to be most useful (specificity and efficiency > 90%) were as follows: Mandel test = CSRT > or = 534 ms, Narula test = TECASA > or = 339 ms, heart rate < or = 55/min, type II, IIa and chaotic Strauss curve associated with a pathological Guize test. The combination of these tests in this algorithm resulted in an increase in sensitivity to 84%, at the price of a very moderate fall in specificity to 87%.(ABSTRACT TRUNCATED AT 250 WORDS)

[Measurement of pacemaker effect: incidences on the choice of pacing mode? A prospective and statistical study of 396 patients]

Single ventricular stimulation induces haemodynamic disturbances, the best known of which is the pacemaker syndrome. In order to assess the prevalence and severity of these abnormalities, invasive blood pressure monitoring was performed in 396 consecutive patients undergoing endocavitary electrophysiological investigations: a decrease in systolic blood pressure at a rate near to that of the spontaneous rhythm defines the pacemaker syndrome. It is maximal after 3 to 5 beats of equivalent intensity with or without retrograde conduction. The pacemaker syndrome is greater in hypertensive and coronary patients than in subjects with healthy hearts (-44.2 mmHg and -37.2 mmHg versus -33 mmHg, p < 0.001 and p < 0.04). It is less pronounced in cases of cardiac failure (-31.8 mmHg). The pacemaker syndrome increases in intensity with age (-44.3 mmHg after 80 years of age versus -23.1 mmHg in subjects under 50 years of age; p < 0.001). Two electrophysiological abnormalities are associated with an increased pacemaker syndrome even in apparently normal hearts: sustained induced supraventricular tachycardia (-34.2 mmHg versus -26 mmHg, p < 0.002), mixed carotid sinus syndromes (-38 mmHg) and pure vasodepressive syndromes (-48.5 mmHg, p < 0.001). The study of the pacemaker syndrome is useful for three reasons: the detection of another cardiac abnormality in cases of sustained induced supraventricular tachycardia, even in an apparently healthy heart; to assess the presence of a second haemodynamic abnormality independent of the vagal effect in cases of carotid sinus syndrome with vasodepression; finally, to identify the patients at high risk of a pacemaker syndrome.

[Value of intravenous flecainide in electro-induced supraventricular arrhythmia. Apropos of 37 cases]

Thirty-seven patients presenting with electro-induced supraventricular arrhythmia sustained for more than 10 min or symptomatic received an intravenous injection of flecainide acetate (1.5 mg/kg; 10 mg/min). There were 24 cases of atrial fibrillation, 13 of atrial tachysystole with more than 180 beats per minute. Electrophysiological exploration was carried out for syncope (13 cases), lipothymia with palpitations (11 cases) or without palpitations (8 cases), or for a stroke of unknown origin. The induced arrhythmia was the only electrophysiological abnormality in 57% of cases. A return of sinus rhythm was obtained in 70% of cases during the injection (12 cases) or shortly after the end of the injection (14 patients). Safety was good, with the exception of the onset of two junctional rhythms and one case of non-syncopal monomorphic ventricular tachycardia. After an initial reduction, the PR, QRS, PA and HV intervals were significantly longer than baseline, whereas the AH space and the systolic blood pressure remained virtually unchanged. Thus the provision of IV flecainide acetate can only be beneficial in carrying out study protocols of abnormalities of the atrial substrate.

[Carotid sinus syndrome. Contribution of arterial pressure monitoring to intracavitary electrophysiological exploration]

A prospective study based on intracavitary electrophysiological exploration coupled with invasive arterial pressure monitoring was conducted in 245 patients aged 70.2 +/- 13 years who had experienced syncopes and/or lipothymias of uncertain origin. The study showed that 63 patients (25.7 p. 100) had carotid sinus syndrome (CSS). The syndrome was of the vagal type (cardiac inhibition) in 27 p. 100 of the cases, of the depressor type (vasodepression) in 22 p. 100 of the cases and mixed in 51 p. 100 of the cases with the two types of pathological response: electrophysiological and haemodynamic. Compared with the remaining 182 patients, these 63 patients were more frequently male (63.5 p. 100, p less than 0.01), of the same age (71.7 years, NS) and more symptomatic, meaning that syncopes occurred in 80 p. 100 of the cases and that their number per patient was higher (2.92, p less than 0.01). A predisposing factor (usually a vagal predominance) was found in 26.9 p. 100 of the cases. In 30 p. 100 of the patients CSS was associated with a sinus node disease or with disorders of atrioventricular conduction. Another haemodynamic abnormality often associated with CSS was a more pronounced (-38.7 mmHg, p less than 0.01) and more frequent (68 p. 100, p less than 0.01) pacemaker effect. 62 p. 100 of patients with mixed CSS had an increase in systolic arterial pressure during vagogenic manoeuvres with DDD mode stimulation as compared with the VVI mode stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)