Cell growth in aggregates determines gene expression, proliferation, survival, chemoresistance, and sensitivity to immune effectors in follicular lymphoma.
Lymphomas grow as dense aggregates in patients, but whether this spatial organization affects lymphoma cell biology is unknown. We grew follicular lymphoma (FL) cells in vitro as multicellular aggregates of lymphoma cells to investigate this question. Gene expression analysis revealed that 612 genes were differentially expressed when cells grew in multicellular aggregates of lymphoma cells rather than in suspension. These genes correspond to several GO biological processes, such as hypoxia, activation of NF-κB pathway, and negative regulation of cell cycle, a gene signature also found in the transcriptomes from FL biopsies. Pimonidazole staining, HIF-1A accumulation, and VEGFA release confirmed that cells in multicellular aggregates of lymphoma cells actually respond to hypoxia. In adaptation to such conditions, they also displayed an activated NF-κB pathway and a quiescent status far more frequently than in suspension. When cultured in three dimensions, FL cells display resistance to doxorubicin and bendamustine, two drugs largely used in FL therapy, compared to FL cultured in suspension. Finally, multicellular aggregates of lymphoma cells were also found to be less sensitive to purified natural killer cells. To conclude, our study shows that in FL, spatial organization results in dramatic changes in FL biology, including gene expression, proliferation, drug resistance, and immune escape.
National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France. Electronic address: pauline.gravelle@inserm.fr.
Pauline
P
Gravelle
National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France.
Christine
C
Jean
National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France.
Julien
J
Familiades
National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France; Roche Research Institute, Boulogne Billancourt, France.
Emilie
E
Decaup
National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France.
Amandine
A
Blanc
National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France.
Christine
C
Bezombes-Cagnac
University of Toulouse III: Paul Sabatier, Toulouse, France; INSERM UMR1047, Center for Pathophysiology of Toulouse Purpan, Toulouse, France; Department of Anatomopathology, Hospital Purpan, Toulouse, France.
Camille
C
Laurent
S.A.S. Roche, Boulogne Billancourt, France.
Ariel
A
Savina
National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France.
Jean-Jacques
JJ
Fournié
National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France; Department of Hematology, Hospital Purpan, Toulouse, France.
Guy
G
Laurent
D015153:Blotting, Western; D018929:Cell Culture Techniques / Q000379:methods; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival / Q000502:physiology; D019008:Drug Resistance, Neoplasm / Q000502:physiology; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D008224:Lymphoma, Follicular / Q000235:genetics* / Q000276:immunology* / Q000473:pathology*; D059467:Transcriptome; D014161:Transduction, Genetic; D019139:Tumor Escape / Q000502:physiology*