Identification of molecular targets associated with transformed diffuse large B cell lymphoma using highly purified tumor cells.
Follicular lymphoma (FL) frequently transforms into the more aggressive diffuse large B cell lymphoma (DLBCL-tr), but no protein biomarkers have been identified for predictive or early diagnosis. Gene expression analyses have identified genes changing on transformation but have failed to be reproducible in different studies, reflecting the heterogeneity within the tumor tissue and between tumor samples. Gene expression analyses on Affymetrix Human Genome U133 Plus 2.0 arrays were performed, using flow cytometry sorted tumor cells derived from FL and transformed DLBCL. To identify molecular targets associated with the transformation, subsequent immunohistochemistry (IHC) analyses of the corresponding proteins were performed. Using highly purified cells, this study identified 163 genes, which were significantly deregulated during the transformation in a majority of cases. Among the upregulated transcripts, 13 genes were selected for validation using IHC, based on the availability of commercial antibodies, and galectin-3 and NEK2 proteins specifically identify DLBCL-tr, when compared with FL. We demonstrate that by purifying tumor cells through cell sorting, thereby reducing the heterogeneity due to infiltrating cells, it was possible to identify distinct differences between tumor entities rather than variations due to cellular composition. Galectin-3 and NEK2 both identified a subgroup of DLBCL-tr, and the function of these protein markers also suggests a biological role in the transformation process.
Department of Immunotechnology, Lund University, Lund, Sweden.
Ulrika
U
Andréasson
Michael
M
Dictor
Mats
M
Jerkeman
Mattias
M
Berglund
Christer
C
Sundström
Johan
J
Linderoth
Richard
R
Rosenquist
Carl A K
CA
Borrebaeck
Sara
S
Ek
D014408:Biomarkers, Tumor / Q000032:analysis*; D002469:Cell Separation / Q000379:methods*; D018450:Disease Progression; D042241:Early Diagnosis; D005434:Flow Cytometry / Q000379:methods*; D037502:Galectin 3 / Q000032:analysis* / Q000235:genetics; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008224:Lymphoma, Follicular / Q000473:pathology; D016403:Lymphoma, Large B-Cell, Diffuse / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000072379:NIMA-Related Kinases; D009363:Neoplasm Proteins / Q000032:analysis* / Q000235:genetics; D011237:Predictive Value of Tests; D017346:Protein Serine-Threonine Kinases / Q000032:analysis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D012334:RNA, Neoplasm / Q000032:analysis
D014408:Biomarkers, Tumor; D037502:Galectin 3; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; C089441:NEK2 protein, human; D000072379:NIMA-Related Kinases; D017346:Protein Serine-Threonine Kinases