Phenotypic Alterations in Kaposi’s Sarcoma Cells by Antisense Reduction of Perlecan

Chiara MARCHISONE1, Federica DEL GROSSO3, Luciana MASIELLO2, Maria PRAT0, Leonardo SANTI5, Douglas M NOONAN1

0Laboratorio di Istologia, Dep. of Medical Sciences, Università del Piemonte Orientale ''A. Avogadro”, Novara, Italy
1Modulo di Progressione Neoplastica, Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy
2Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy
3Centro di Biotecnologie Avanzate, Genova, Italy
5Dip. di Oncologia, Biologia e Genetica, Universitá di Genova, Genova, Italy


Metastasis is a sequence of events including proliferation, migration, adhesion, invasion and subsequent metastatic growth of tumour cells in distant organs. We previously showed that highly metastatic variants of murine melanoma cells express higher levels of the basement membrane proteoglycan perlecan than low or non metastatic variants and expression of an antisense perlecan can reduce metastatic potential. In contrast, antisense expression of perlecan in fibrosarcoma cells was reported to enhance tumorigenesis. To better understand the role of perlecan in angiogenesis we have transfected KS-IMM, an immortalized cell line derived from a human Kaposi’s sarcoma, with an antisense perlecan construct and investigated the positive/negative role of perlecan in KS. KS-IMM cells were transfected with either empty vector (neo) or the antisense perlecan construct and clones were isolated. Immuno-blot analysis showed a reduction of perlecan levels in two (AP3 and AP4) isolated clones, in Northern blot analysis endogenous perlecan was undetectable in the AP3 and AP4 clones, while it was present in the neo control clones. AP clones had a reduced migration to HGF in Boyden chambers as compared to neo clones. Proliferation in low serum or serum-free conditions was strongly reduced in the AP clones as compared to the neo control cells. The neotransfected cells showed rapid proliferation in low serum supplemented with HGF and VEGF, while antisense transfected clones showed little response. Finally, AP-trasfected KS-IMM cells had significantly reduced migration to VEGF and HGF with respect to controls. In contrast, when the AP transfected cells were injected in nude mice they paradoxically showed enhanced tumor growth as compared to controls. Our preliminary data indicate that perlecan reduction plays a crucial role on Kaposi’s sarcoma cell migration and proliferation in vitro. However, in vivo KS-IMM depleted of perlecan had a growth advantage. A possible hypothesis is that perlecan is necessary for growth of KS-IMM cells in vitro, however its down-regulation might promote angiogenesis through increased angiogenic growth factor diffusion, resulting in enhanced tumor growth in vivo. Pathology & Oncology Research, Vol 6, Nr 1, 10-17, 2000

Key words: Kaposi-sarcoma; perlecan; antisense

Received: Jan 4, 2000; accepted: Feb 10, 2000
Correspondence: Douglas M NOONAN, Modulo di Progressione Neoplastica, Istituto Nazionale per la Ricerca sul Cancro, c/o Centro di Biotecnologie Avanzate, Largo Rosana Benzi, n. 10 Genova 16132, Italy; Tel: +39 010 5737367, Fax: +39 010 5737364; E-mail:

Click here to get the full-text version in PDF!