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L'infection et la réponse immunitaire au virus SARS-CoV-2 de la population au contact de personnes vulnérables ont été des questions majeures dès le début de la pandémie. L'objectif de l’étude était d’évaluer le statut immunitaire sérologique à l'infection par le SARS-CoV-2 chez les professionnels d'un établissement de santé en cancérologie. L’évolution dans le temps de ce statut, la caractérisation des cas de COVID-19 et la présence de troubles anxieux (étude optionnelle) ont également été étudiés.

Gastric carcinoma is the third leading cause of cancer-related death worldwide. This cancer, most of the time metastatic, is essentially treated by surgery associated with conventional chemotherapy, and has a poor prognosis. The existence of cancer stem cells (CSC) expressing CD44 and a high aldehyde dehydrogenase (ALDH) activity has recently been demonstrated in gastric carcinoma and has opened new perspectives to develop targeted therapy. In this study, we evaluated the effects of all-trans-retinoic acid (ATRA) on CSCs in human gastric carcinoma. ATRA effects were evaluated on the proliferation and tumorigenic properties of gastric carcinoma cells from patient-derived tumors and cell lines in conventional 2D cultures, in 3D culture systems (tumorsphere assay) and in mouse xenograft models. ATRA inhibited both tumorspheres initiation and growth in vitro, which was associated with a cell-cycle arrest through the upregulation of cyclin-dependent kinase (CDK) inhibitors and the downregulation of cell-cycle progression activators. More importantly, ATRA downregulated the expression of the CSC markers CD44 and ALDH as well as stemness genes such as Klf4 and Sox2 and induced differentiation of tumorspheres. Finally, 2 weeks of daily ATRA treatment were sufficient to inhibit gastric tumor progression in vivo, which was associated with a decrease in CD44, ALDH1, Ki67 and PCNA expression in the remaining tumor cells. Administration of ATRA appears to be a potent strategy to efficiently inhibit tumor growth and more importantly to target gastric CSCs in both intestinal and diffuse types of gastric carcinoma.

Often described as a mediator of cell cycle arrest or as a pro-apoptotic factor in stressful conditions, the MAP3K ZAK (Sterile alpha motif and leucine zipper-containing kinase) has also been proven to positively regulate epidermal growth factor receptor (EGFR) and WNT signaling pathways, cancer cell proliferation and cellular neoplastic transformation. Here, we show that both isoforms of ZAK, ZAK-a and ZAK-ß are key factors in cancer cell migration. While ZAK depletion reduced cell motility of HeLa and HCT116 cells, its overexpression triggered the activation of all three mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinase (ERK), c-JUN N-terminal kinase (JNK) and p38, as well as an increase in cell motion. On the contrary, the kinase-dead mutants, ZAK-a K45M and ZAK-ß K45M, were not able to provoke such events, and instead exerted a dominant-negative effect on MAPK activation and cell migration. Pharmacological inhibition of ZAK by nilotinib, preventing ZAK-autophosphorylation and thereby auto-activation, led to the same results. Activated by epidermal growth factor (EGF), we further showed that ZAK constitutes an essential element of the EGF/ERK-dependent cell migration pathway. Using public transcriptomic databases and tissue microarrays, we finally established that, as strong factors of the EGFR signaling pathway, ZAK-a and/or ZAK-ß transcripts and protein(s) are frequently upregulated in colorectal adenoma and carcinoma patients. Notably, gene set enrichment analysis disclosed a significant correlation between ZAK+ colorectal premalignant lesions and gene sets belonging to the MAPK/ERK and motility-related signaling pathways of the reactome database, strongly suggesting that ZAK induces such pro-tumoral reaction cascades in human cancers.

This study was conducted to determine the prognostic influence of obvious peritumoral vascular emboli as prospectively determined by a simple routine slide examination in patients with operable node-negative breast cancer. Obvious peritumoral emboli (OPE) were defined by the presence of neoplastic emboli within unequivocal vascular lumina (including both lymphatic spaces and blood capillaries) in areas adjacent to but outside the margins of the carcinoma. OPE were assessed routinely on 5μm thick haematoxylin and eosin-stained sections for each of 1320 primary operable node-negative breast cancers from 1975 to 1992 at our institution. OPE and other prognostic variables (tumour size, SBR grade, oestrogen and progesterone receptor status) were correlated to overall survival (OS) and metastasis-free interval (MFI) by means of univariate and multivariate analysis with a median follow-up of 103 months. OPE were found in 19.5% of tumours. In univariate analysis, OPE were related to tumour size (P=6.3×10−5) and histologic grade (P=4.9×10−7). Statistically significant correlations were found with OS (P=4.6×10−5) and MFI (P=6.4×10−9). Furthermore, in multivariate analysis, OPE was an independent prognostic variable, the most predictive factor for MFI (P=7.7×10−7) before tumour size and grade, and was second after tumour grade for OS (P=0.002). This study on a large unicentric series and with a long follow-up confirms the prognostic significance of vascular emboli in patients with operable node-negative breast carcinoma. Importantly, vascular emboli were found to be accurately detectable by a simple routine and non-time-consuming method. Therefore, such obvious vascular emboli should be considered as an important cost-effective, prognostic variable in patients with node-negative breast carcinoma.

Seventy-four post menopausal patients with primary non-metastatic invasive ductal carcinomas of the breast were first treated with tamoxifen alone (30 mg p.o. daily) for 5 months. To study changes induced by tamoxifen, core biopsies before treatment and surgical specimens after hormonal therapy were assayed by immunohistochemistry for oestrogen (ER) and progesterone receptors (PR), pS2, GSTpi and c-erbB2. After tamoxifen, ER and PR significantly decreased in 60 and 44 cases respectively, whereas 11 and 19 cases showed no variation and 2 and 11 cases showed an increase (P<10(-4)). GSTpi and pS2 showed a significant increase in 43 and 41 cases, a decrease in 2 and 21 cases and no variation in 29 and 12 cases (P<10(-4) and P=0.04 respectively). c-erbB-2 showed no significant variation under tamoxifen, increased in only three cases and decreased in 13 cases. No relation was found between these variations and efficiency of hormone therapy. Our results allow a better knowledge of protein expression modifications occurring in breast cancer cells under tamoxifen therapy. They are also more consistent with clone selection rather than with phenotype modification.

Tamoxifen as sole initial therapy is gaining importance in the management of post-menopausal breast cancer patients. Age oestrogen (ER) and progesterone (PR) receptor status are accurately considered to select patients for hormonal treatment. However, additional markers are needed. By immunohistochemistry (IHC), we studied tumour expression of ER, PR, pS2, c-erbB-2 and glutathione S-transferase pi (GST pi) on initial core biopsies of 208 post-menopausal patients with a non-metastatic invasive ductal carcinoma, treated by neoadjuvant tamoxifen therapy. A good response to tamoxifen was defined as tumoral regression > or = 50% (110 patients). Relationship between response and age, tumour size, T, N, histological grade, ER and PR contents evaluated by radioimmunoassay, ER, PR, pS2, c-erbB-2 and GST pi expression evaluated by IHC were studied. Univariate and multivariate analysis showed that tumoral regression was linked only to pS2 (P = 0.004) and ER (P = 0.018) IHC expression. According to the immunohistochemical profile, three groups could be defined: pS2- and ER-positive tumours, pS2- or ER-positive tumours and pS2- and ER-negative tumours with response rates of 60%, 45% and 8% respectively. Although prospective studies are needed to confirm these results, we conclude that pS2 and ER immunohistochemical status are useful tools for predicting tumour regression with neoadjuvant tamoxifen in post-menopausal breast carcinoma patients.

Malgré les progrès récents le cancer anaplasique thyroïdien reste de pronostic sombre sans réelle possibilité thérapeutique. De façon parallèle, les techniques récentes de biologie moléculaire pourraient permettre une meilleure compréhension des différentes voix d’activation et ainsi déboucher sur des traitements plus adaptés au profil moléculaire de ces tumeurs.