Calcium Independent Effect of Orai1 and STIM1 in Non-Hodgkin B Cell Lymphoma Dissemination

International audienceCa 2+ release-activated Ca 2+ channels, composed of Orai1 and STIM1 (stromal interaction molecule 1) proteins, are the main Ca 2+ entry mechanism in lymphocytes. Their role in cell migration and metastasis is demonstrated in solid cancers but it remains elusive in malignant hemopathies. Diffuse large B cell lymphoma (DLBCL) is characterized by the dissemination of neoplastic B cells throughout the organism which is under the control of chemokines such as Stromal Derived Factor 1 (SDF-1) and its receptor CXCR4. CXCR4 activation triggers a complex intracellular signaling including an increase in intracellular Ca 2+ concentration whose role is still unclear. Using pharmacological and genetic approaches, we revealed that STIM1 and Orai1 were responsible for Ca 2+ influx induced by SDF-1. Furthermore, we provide in vitro and in vivo evidence that they are necessary for basal or SDF-1-induced DLBCL cell migration which is independent of Ca 2+ entry. We identify that they act as effectors coupling RhoA and ROCK dependent signaling pathway to MLC2 phosphorylation and actin polymerization. Finally, we revealed an alteration of Orai1 and STIM1 expression in extra-nodal DLBCL. Thus, we discovered a novel Ca 2+-independent but Orai1 and STIM1-dependent signaling pathway involved in basal and CXCR4 dependent cell migration, which could be relevant for DLBCL physiopathology

Routine molecular profiling of cancer: results of a one-year nationwide program of the French Cooperative Thoracic Intergroup (IFCT) for advanced non-small cell lung cancer (NSCLC) patients.

International audienceBackground: The molecular profiling of patients with advanced non-small-cell lung cancer (NSCLC) for known oncogenic drivers is recommended during routine care. Nationally, however, the feasibility and effects on outcomes of this policy are unknown. We aimed to assess the characteristics, molecular profiles, and clinical outcomes of patients who were screened during a 1-year period by a nationwide programme funded by the French National Cancer Institute. Methods This study included patients with advanced NSCLC, who were routinely screened for EGFR mutations, ALK rearrangements, as well as HER2 (ERBB2), KRAS, BRAF, and PIK3CA mutations by 28 certified regional genetics centres in France. Patients were assessed consecutively during a 1-year period from April, 2012, to April, 2013. We measured the frequency of molecular alterations in the six routinely screened genes, the turnaround time in obtaining molecular results, and patients' clinical outcomes. This study is registered with ClinicalTrials.gov, number NCT01700582. Findings 18 679 molecular analyses of 17 664 patients with NSCLC were done (of patients with known data, median age was 64·5 years [range 18–98], 65% were men, 81% were smokers or former smokers, and 76% had adenocarcinoma). The median interval between the initiation of analysis and provision of the written report was 11 days (IQR 7–16). A genetic alteration was recorded in about 50% of the analyses; EGFR mutations were reported in 1947 (11%) of 17 706 analyses for which data were available, HER2 mutations in 98 (1%) of 11 723, KRAS mutations in 4894 (29%) of 17 001, BRAF mutations in 262 (2%) of 13 906, and PIK3CA mutations in 252 (2%) of 10 678; ALK rearrangements were reported in 388 (5%) of 8134 analyses. The median duration of follow-up at the time of analysis was 24·9 months (95% CI 24·8–25·0). The presence of a genetic alteration affected first-line treatment for 4176 (51%) of 8147 patients and was associated with a significant improvement in the proportion of patients achieving an overall response in first-line treatment (37% [95% CI 34·7–38·2] for presence of a genetic alteration vs 33% [29·5–35·6] for absence of a genetic alteration; p=0·03) and in second-line treatment (17% [15·0–18·8] vs 9% [6·7–11·9]; p<0·0001). Presence of a genetic alteration was also associated with improved first-line progression-free survival (10·0 months [95% CI 9·2–10·7] vs 7·1 months [6·1–7·9]; p<0·0001) and overall survival (16·5 months [15·0–18·3] vs 11·8 months [10·1–13·5]; p<0·0001) compared with absence of a genetic alteration. Interpretation Routine nationwide molecular profiling of patients with advanced NSCLC is feasible. The frequency of genetic alterations, acceptable turnaround times in obtaining analysis results, and the clinical advantage provided by detection of a genetic alteration suggest that this policy provides a clinical benefit

Identification de gènes impliqués dans le développement des Lymphomes Cutanés Primitifs CD30+

Le lymphome cutané primitif (LCP) CD30+ est une lymphoprolifération maligne de phénotype T. Son oncogenèse reste à ce jour inconnue. Le but de ma thèse est d'identifier des gènes exprimés spécifiquement dans les LCP CD30+ afin de comprendre les mécanismes d'oncogenèse et également d'identifier des marqueurs diagnostics ou thérapeutiques. Des banques d'ADNc soustraites par SSH (Soustractive Suppressive Hybrididation) entre des LCP CD30+ et des lymphocytes sanguins. Ces banques sont ensuite criblées par des techniqes de Dot Blot avec des sondes radiomarquées spécifiques des échantillons étudiés. Les clones sélectionnés sont enfin validés par PCR en temps réel. Nous avons ainsi mis en évidence cinq gènes surexprimés dans les LCP CD30+ : THW,p120caténine, SPARC, PTTG1, CD30 et cinq gènes sousexprimés : humanine, CIN85, Bcl11B, CD30 L et CD30s. Il reste à vérifier si ces gènes sont responsables de l'oncogenèse ou s'ils sont uniquement des phénotypes des LCP CD30+.The CD30+ Primary Cutaneous Lymphoma (PCL) is a malignant T-cells lymphoproliferation. Its oncogenesis remains currently unknown. The aim of my thesis is to identify genes expressed specifically in CD30+ PCL in order to understand the mechanisms of oncogenesis and also to identify diagnostic or therapeutics markers. The substracted libraries of cDNA are obtained by SSH (suppressive substractive hybridisation) between CD30+ PCL and blood lymphocytes. These libraries are then screened by dot blot techniques with specific radiolabelled probes of the studied samples. The selected clones are finally validated by real time PCR.We have thus found five genes over expressed in CD30+ PCL : THW, p120catenin, SPARC, PTTG1, and CD30 and five genes under expressed : humanin, CIN85, Bcl11B, CD30L and CD30s. It remains to be checked if these genes are responsible for oncogenesis or if they are uniquely phenotypes of CD30+PCL.BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

Telomerase Activation in Hematological Malignancies

Telomerase expression and telomere maintenance are critical for cell proliferation and survival, and they play important roles in development and cancer, including hematological malignancies. Transcriptional regulation of the rate-limiting subunit of human telomerase reverse transcriptase gen (hTERT) is a complex process, and unveiling the mechanisms behind its reactivation is an important step for the development of diagnostic and therapeutic applications. Here, we review the main mechanisms of telomerase activation and the associated hematologic malignancies

hMZF-2, the Elusive Transcription Factor

International audienc

Intravascular large B-cell lymphoma involving pleural solitary fibrous tumor: A case report and literature review

Intravascular large B-cell lymphoma (IVLBCL) is a very rare type of extranodal large B-cell lymphoma that selectively grows within vessels and can spread to any organs or tissues. A very few cases of synchronicity with malignant tumor have yet been described. We report a rare case of IVLBCL accompanying a pleural malignant solitary fibrous tumor (MSFT). A 76-year-old man presented with a chronic dry cough, fever, minor general state deterioration and pancytopenia. Imaging revealed a large pleural mass. Histologically, the mass consisted of a MSFT. However, CD20+ malignant round cells were scattered within lumina of intratumoral blood vessels, evidencing a synchronous IVLBCL occurrence. Molecular analysis of the lymphoid clone identified MYD88 and CD79B gene mutations. After pleural mass excision, global health’s patient improved with cytopenia correction. However, a general state deterioration appeared 4 months after surgery, associated with a large retroperitoneal mass presenting the same pathological and molecular patterns identical to the initial IVLBCL clone

Tumor homogeneity between primary and metastatic sites for BRAF status in metastatic melanoma determined by immunohistochemical and molecular testing.

BRAF inhibitors have demonstrated improvement of overall survival in patients with metastatic melanoma and BRAF(V600) mutations. In order to evaluate BRAF tumor heterogeneity between primary and metastatic site, we have evaluated the performance of immunohistochemistry (IHC) with an anti-BRAF(V600E) antibody in both localization by comparison with high resolution melting analysis followed by Sanger sequencing in a parallel blinded study. A total of 230 samples distributed as primary melanoma (n = 88) and different types of metastatic samples (n = 142) were studied in 99 patients with advanced or metastatic melanoma (stage III or IV). The prevalence of each BRAF mutation was c.1799T>A, BRAF(V600E) (45.2%), c.1799_1800TG>AA, BRAF(V600E2) (3.0%), c.1798_1799GT>AA, BRAF(V600K) (3.0%), c.1801 A>G, BRAF(K601E) (1.3%), c.1789_1790CT>TC, BRAF(L597S) (0.4%), c.1780G>A, BRAF(D594N) (0.9%) respectively. IHC was positive in 109/112 samples harboring BRAF(V600E/E2) mutations and negative in other cases. The cytoplasmic staining was either strongly positive in tumor cells of BRAF(V600E) mutated cases. It appeared strong brown, different from the vesicular grey cytoplasmic pigmentation of melanophages. Concordance between the two techniques was 96.4%. Sensitivity of IHC for detecting the BRAF(V600E/E2) mutations was 97.3%, while specificity was 100%. Both our IHC and molecular study demonstrated homogeneity between primary and metastatic sites for BRAF status in melanoma. This study also provides evidence that IHC may be a cost-effective first-line method for BRAF(V600E) detection. Thereafter, molecular techniques should be used in negative, ambiguous or non-contributive cases