title: Osteopontin expression correlates with melanoma invasion.
abstract: Melanoma is one of the most aggressive cancers affecting humans. Although early melanomas are curable with surgical excision, metastatic melanomas are associated with high mortality. The mechanism of melanoma development, progression, and metastasis is largely unknown. In order to uncover genes unique to melanoma cells, we used high-density DNA microarrays to examine the gene expression profiles of metastatic melanoma nodules using benign nevi as controls. Over 190 genes were significantly overexpressed in metastatic melanomas compared with normal nevi by at least 2-fold. One of the most abundantly expressed genes in metastatic melanoma nodules is osteopontin (OPN). Immunohistochemistry staining on tissue microarrays and individual skin biopsies representing different stages of melanoma progression revealed that OPN expression is first acquired at the step of melanoma tissue invasion. In addition, blocking of OPN expression by RNA interference reduced melanoma cell numbers in vitro. Our observations suggest that OPN may be acquired early in melanoma development and progression, and may enhance tumor cell growth in invasive melanoma.
authors.affiliation: Division of Dermatology, Department of Medicine, University British Columbia, Vancouver, Canada. ywzhou@interchange.ubc.ca
authors.forename: Youwen
authors.initials: Y
authors.lastname: Zhou
authors.forename: Derek L
authors.initials: DL
authors.lastname: Dai
authors.forename: Magdalena
authors.initials: M
authors.lastname: Martinka
authors.forename: Mingwan
authors.initials: M
authors.lastname: Su
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Eric I
authors.initials: EI
authors.lastname: Campos
authors.forename: Irene
authors.initials: I
authors.lastname: Dorocicz
authors.forename: Liren
authors.initials: L
authors.lastname: Tang
authors.forename: David
authors.initials: D
authors.lastname: Huntsman
authors.forename: Colleen
authors.initials: C
authors.lastname: Nelson
authors.forename: Vincent
authors.initials: V
authors.lastname: Ho
authors.forename: Gang
authors.initials: G
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008545:Melanoma / Q000473:pathology* / Q000556:secondary; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D020411:Oligonucleotide Array Sequence Analysis; D053495:Osteopontin; D012333:RNA, Messenger / Q000032:analysis; D034741:RNA, Small Interfering / Q000494:pharmacology; D012795:Sialoglycoproteins / Q000032:analysis / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D034741:RNA, Small Interfering; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D053495:Osteopontin