<em>Ex Vivo</em> Imaging of Resident CD8 T Lymphocytes in Human Lung Tumor Slices Using Confocal Microscopy

CD8 T cell are key players in the fight against cancer. In order for CD8 T cells to kill tumor cells they need to enter into the tumor, migrate within the ...

Université Paris Descartes

University Pierre and Marie Curie

Histologic classification of lung adenocarcinoma subtype has a prognostic value in most studies. However, lung adenocarcinoma characteristics differ across countries. Here, we aimed at validating the prognostic value of this classification in a large French series of lung adenocarcinoma.

The new histologic classification of lung primary adenocarcinoma subtypes is a reliable prognostic marker and identifies tumors with different mutation status: the experience of a French cohort.

Activating epidermal growth factor receptor (EGFR) mutations characterize a subgroup of non-small-cell lung cancer that benefit from first line EGFR tyrosine kinase inhibitors (EGFR-TKI). However, the existence of polyclonal cell populations may hinder personalized-medicine strategies as patients' screening often depends upon a single tumor-biopsy sample. The purpose of this study is to clarify and to validate in clinical testing conditions the accuracy of EGFR genotyping using different tumor sites and various types of samples (transthoracic, surgical or endoscopic biopsies and cytology specimens).

Intratumoral distribution of EGFR mutations and copy number in metastatic lung cancer, what impact on the initial molecular diagnosis?

Alterations in the signaling pathways of epidermal growth factor receptors (HERs) are associated with tumor aggressiveness. Neurotensin (NTS) and its high affinity receptor (NTSR1) are up regulated in 60% of lung cancers. In a previous clinical study, NTSR1 overexpression was shown to predict a poor prognosis for 5 year overall survival in a selected population of stage I lung adenocarcinomas treated by surgery alone. In a second study, shown here, the frequent and high expression of NTSR1 was correlated with a pejorative prognosis in 389 patients with stage I to III lung adenocarcinoma, and was an independent prognosis marker. Interactions between NTS and NTSR1 induce pro-oncogenic biological effects associated with neoplastic processes and tumor progression. Here we highlight the cellular mechanisms activated by Neurotensin (NTS) and its high affinity receptor (NTSR1) contributing to lung cancer cell aggressiveness. We show that the NTS autocrine and/or paracrine regulation causes EGFR, HER2, and HER3 over-expression and activation in lung tumor cells. The EGFR and HER3 autocrine activation is mediated by MMP1 activation and EGF "like" ligands (HB-EGF, Neuregulin 1) release. By establishing autocrine and/or paracrine NTS regulation, we show that tumor growth is modulated according to NTS expression, with a low growth rate in those tumors that do not express NTS. Accordingly, xenografted tumors expressing NTS and NTSR1 showed a positive response to erlotinib, whereas tumors void of NTSR1 expression had no detectable response. This is consistent with the presence of a NTS autocrine loop, leading to the sustained activation of EGFR and responsible for cancer aggressiveness. We propose the use of NTS/NTSR1 tumor expression, as a biomarker for the use of EGFR tyrosine kinase inhibitors in patients lacking EGFR mutation.

Neurotensin (NTS) and its receptor (NTSR1) causes EGFR, HER2 and HER3 over-expression and their autocrine/paracrine activation in lung tumors, confirming responsiveness to erlotinib.

Anaplastic lymphoma kinase (ALK) gene rearrangements in lung adenocarcinoma result in kinase activity targetable by crizotinib. Although fluorescence in situ hybridisation (FISH) is the reference diagnostic technique, immunohistochemistry (IHC) could be useful for pre-screening. Diagnostic yields of ALK IHC, FISH and quantitative reverse transcriptase PCR performed in 14 French pathology/molecular genetics platforms were compared. 547 lung adenocarcinoma specimens were analysed using 5A4 and D5F3 antibodies, two break-apart FISH probes and TaqMan kits. Clinicopathological data were recorded. 140 tumours were ALK rearranged (FISH with ≥15% of rearranged cells) and 400 were ALK FISH negative (<15%). FISH was not interpretable for seven cases. ALK patients were young (p=0.003), mostly females (p=0.007) and light/nonsmokers (p<0.0001). 13 cases were IHC negative but FISH ≥15%, including six cases with FISH between 15% and 20%; eight were IHC positive with FISH between 10% and 14%. Sensitivity and specificity for 5A4 and D5F3 were 87% and 92%, and 89% and 76%, respectively. False-negative IHC, observed in 2.4% of cases, dropped to 1.3% for FISH >20%. Variants were undetected in 36% of ALK tumours. Discordances predominated with FISH ranging from 10% to 20% of rearranged cells and were centre dependent. IHC remains a reliable pre-screening method for ALK rearrangement detection.

French multicentric validation of ALK rearrangement diagnostic in 547 lung adenocarcinomas.

T cells play a key role in the battle against cancer. To perform their antitumor activities, T cells need to adequately respond to tumor antigens by establishing contacts with either malignant cells or antigen-presenting cells. These latter functions rely on a series of migratory steps that go from entry of T cells into the tumor followed by their locomotion in the tumor stroma. Our knowledge of how T cells migrate within tumors mainly comes from experiments performed in mouse models. Whereas such systems have greatly advanced our understanding, they do not always faithfully recapitulate the disease observed in cancer patients. We previously described a technique based on tissue slices that enables to track with real-time imaging microscopy the motile behavior of fluorescent T cells plated onto fresh sections of human lung tumors. We have now refined this approach to monitor the locomotion of resident tumor-infiltrating CD8 T cells labeled with fluorescently coupled antibodies. Using this approach, our findings reveal that CD8 T cells accumulate in the stroma of ovarian and lung carcinomas but move slowly in this compartment. Conversely, even though less populated, tumors islets were found to be zones of faster migration for resident CD8 T cells. We also confirm the key role played by collagen fibers, which, by their orientation, spacing and density, control the distribution and migration of resident CD8 T cells within the tumor stroma. We have subsequently demonstrated that, under some physical tissue constraints, CD8 T cells exhibited a mode of migration characterized by alternate forward and backward movements. In sum, using an ex vivo assay to track CD8 T cells in fresh human tumor tissues, we have identified the extracellular matrix as a major stromal component in influencing T cell migration, thereby impacting the control of tumor growth. This approach will aid in the development and testing of novel immunotherapy strategies to promote T cell migration in tumors.

Real-Time Imaging of Resident T Cells in Human Lung and Ovarian Carcinomas Reveals How Different Tumor Microenvironments Control T Lymphocyte Migration.

Tumor-infiltrating immune cells affect lung cancer outcome. However, the factors that influence the composition and function of the tumor immune environment remain poorly defined and need investigation, particularly in the era of immunotherapy.

Intratumoral Immune Cell Densities Are Associated with Lung Adenocarcinoma Gene Alterations.

At the Paris Descartes medicine faculty, we tested some newly developed tools to enhance the pedagogic value of the pathology teaching. In our faculty, this teaching is largely multidisciplinary and integrated in various teaching units; a large part is dedicated to practice works with thirteen 90min sessions. Virtual slides have been used for years in numerous medicine faculties; we successfully implemented this tool by adding contextual annotations, which facilitate students revising. We showed that rewarding students' assiduity enhanced their exam success. To do so, we now propose a short continuous assessment exam at the beginning of each practice session in the form of electronic multi-choice questions. Finally, we now propose a completely computerized final exam, on touchpads, that enhanced its docimologic value.

Audrey Mansuet-Lupo

Department of Pathology,
Paris Centre University Hospitals,
Department of Pathology, Paris Centre University Hospitals

Université Paris Descartes

Ex Vivo Imaging of Resident CD8 T Lymphocytes in Human Lung Tumor Slices Using Confocal Microscopy

Audrey Mansuet-Lupo

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Pathology,Paris Centre University Hospitals,Department of Pathology, Paris Centre University Hospitals

Université Paris Descartes

Ex Vivo Imaging of Resident CD8 T Lymphocytes in Human Lung Tumor Slices Using Confocal Microscopy

Department of Pathology,
Paris Centre University Hospitals,
Department of Pathology, Paris Centre University Hospitals