title: A novel human heparanase splice variant, T5, endowed with protumorigenic characteristics.
abstract: Heparanase is a mammalian endo-beta-d-glucuronidase that can cleave heparan sulfate side chains, an activity strongly implicated in tumor cell dissemination. The current study aimed to identify and characterize heparanase splice variants. LEADS, Compugen's alternative splicing modeling platform (Compugen, Tel Aviv, Israel), was used to search for splice variants in silico; tumor-derived cell lines (i.e., CAG myeloma) and tumor biopsies were utilized to validate T5 expression in vivo; signaling (i.e., Src phosphorylation) was evaluated following T5 gene silencing or overexpression and correlated with cell proliferation, colony formation, and tumor xenograft development. A novel spliced form of human heparanase, termed T5, was identified. In this splice variant, 144 bp of intron 5 are joined with exon 4, which results in a truncated, enzymatically inactive protein. T5 overexpression resulted in increased cell proliferation and larger colonies in soft agar, mediated by Src activation. Furthermore, T5 overexpression markedly enhanced tumor xenograft development. T5 expression is up-regulated in 75% of human renal cell carcinoma biopsies examined, which suggests that this splice variant is clinically relevant. Controls included cells overexpressing wild-type heparanase or an empty plasmid and normal-looking tissue adjacent the carcinoma lesion. T5 is a novel functional splice variant of human heparanase endowed with protumorigenic characteristics.-Barash, U., Cohen-Kaplan, V., Arvatz, G., Gingis-Velitski, S., Levy-Adam, F., Nativ, O., Shemesh, R., Ayalon-Sofer, M., Ilan, N., Vlodavsky, I. A novel human heparanase splice variant, T5, endowed with protumorigenic characteristics.
authors.affiliation: Cancer and Vascular Biology Research Center, Faculty of Medicine, Technion, P.O. Box 9649, Haifa 31096, Israel.
authors.forename: Uri
authors.initials: U
authors.lastname: Barash
authors.forename: Victoria
authors.initials: V
authors.lastname: Cohen-Kaplan
authors.forename: Gil
authors.initials: G
authors.lastname: Arvatz
authors.forename: Svetlana
authors.initials: S
authors.lastname: Gingis-Velitski
authors.forename: Flonia
authors.initials: F
authors.lastname: Levy-Adam
authors.forename: Ofer
authors.initials: O
authors.lastname: Nativ
authors.forename: Ronen
authors.initials: R
authors.lastname: Shemesh
authors.forename: Michal
authors.initials: M
authors.lastname: Ayalon-Sofer
authors.forename: Neta
authors.initials: N
authors.lastname: Ilan
authors.forename: Israel
authors.initials: I
authors.lastname: Vlodavsky
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D005966:Glucuronidase / Q000096:biosynthesis* / Q000235:genetics; D006497:Heparan Sulfate / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D008957:Models, Genetic; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D009368:Neoplasm Transplantation; D014183:Transplantation, Heterologous; D000099175:Heparanase
chemical_list: D005966:Glucuronidase; D006497:Heparan Sulfate; D009363:Neoplasm Proteins; D000099175:Heparanase