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. 2012 Mar;122(3):1076-81.
doi: 10.1172/JCI58530. Epub 2012 Feb 1.

Direct and efficient cellular transformation of primary rat mesenchymal precursor cells by KSHV

Tiffany Jones  1 , Fengchun Ye, Roble Bedolla, Yufei Huang, Jia Meng, Liwu Qian, Hongyi Pan, Fuchun Zhou, Rosalie Moody, Brent Wagner, Mazen Arar, Shou-Jiang Gao
Affiliations

Direct and efficient cellular transformation of primary rat mesenchymal precursor cells by KSHV

Tiffany Jones et al. J Clin Invest. 2012 Mar.

Abstract

Infections by viruses are associated with approximately 12% of human cancer. Kaposi's sarcoma-associated herpesvirus (KSHV) is causally linked to several malignancies commonly found in AIDS patients. The mechanism of KSHV-induced oncogenesis remains elusive, due in part to the lack of an adequate experimental system for cellular transformation of primary cells. Here, we report efficient infection and cellular transformation of primary rat embryonic metanephric mesenchymal precursor cells (MM cells) by KSHV. Cellular transformation occurred at as early as day 4 after infection and in nearly all infected cells. Transformed cells expressed hallmark vascular endothelial, lymphatic endothelial, and mesenchymal markers and efficiently induced tumors in nude mice. KSHV established latent infection in MM cells, and lytic induction resulted in low levels of detectable infectious virions despite robust expression of lytic genes. Most KSHV-induced tumor cells were in a latent state, although a few showed heterogeneous expression of lytic genes. This efficient system for KSHV cellular transformation of primary cells might facilitate the study of growth deregulation mechanisms resulting from KSHV infections.

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Figures

Figure 1
Figure 1. Characterization of MM and KMM cells.
(A) Morphology at day 2 after seeding. Cells were seeded at 5 × 104 cells/well in 6-well plates. (B and C) Expression of LANA (B) and ORF65 (C) proteins in uninduced KMM cells and KMM cells induced with TPA for 48 hours. (D) Expression of cell surface markers in MM and KMM cells. Scale bars: 50 μm (A, C, and D), 10 μm (B).
Figure 2
Figure 2. Immortalization and transformation of MM cells by KSHV.
(A) MM cells underwent crisis after 25–28 passages. KMM grew continuously without crisis. Cells were passaged every 3 days at 2 × 104 cells/well in 24-well plates. (B) KMM cells grew faster than MM cells in regular medium containing serum. Cells seeded at 105 cells/well in 6-well plates were counted daily. (C) In serum-free medium, growth of MM cells stopped, while KMM cells continued to grow for up to day 4 after seeding. Cells seeded at 105 cells/well in 6-well plates were counted daily. (D) KMM cells formed foci, while MM cells were contact inhibited when they reached confluency. Cells seeded at 2 × 105 cells/well in 6-well plates were cultured with daily medium change. Scale bar: 40 μm. (E) KMM cells formed many large colonies in semisolid soft agar, while MM cells did not. Scale bar: 200 μm.
Figure 3
Figure 3. KMM cells induce tumors in nude mice.
(A) Tumor growth curves. The red thick line indicates average tumor volumes. MM cells did not induce any tumors. (B) Tumor incidence from 5 independent experiments. Numbers above of the bars represent inoculated sites. Results in A were from experiment 3. (C) Representative reddish tumor morphology. (D) Tumor dissemination to visceral organs. Tumors (T) shown in green fluorescence were present in spleen (S), liver (L), lung (Lu), kidney (K), and intestine (I). (E) Immunohistochemical staining for H&E, Ki67, LANA, and ORF65 proteins, the mouse B cell marker CD45Rt, vascular endothelial markers (β-catenin and CD31), lymphatic endothelial markers (LYVE-1 and VEGFR-3), hematopoietic precursor markers (CD34 and Thy1.1), and the mesenchymal marker vimentin. Representative slit-like spaces are labeled with arrowheads. Scale bar: 40 μm.
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References

    1. Parkin DM. The global health burden of infection-associated cancers in the year 2002. Int J Cancer. 2006;118(12):3030–3044. doi: 10.1002/ijc.21731. - DOI - PubMed
    1. Ganem D. KSHV and the pathogenesis of Kaposi sarcoma: listening to human biology and medicine. J Clin Invest. 2010;120(4):939–949. doi: 10.1172/JCI40567. - DOI - PMC - PubMed
    1. Ciufo DM, et al. Spindle cell conversion by Kaposi’s sarcoma-associated herpesvirus: formation of colonies and plaques with mixed lytic and latent gene expression in infected primary dermal microvascular endothelial cell cultures. J Virol. 2001;75(12):5614–5626. doi: 10.1128/JVI.75.12.5614-5626.2001. - DOI - PMC - PubMed
    1. Flore O, Rafii S, Ely S, O’Leary JJ, Hyjek EM, Cesarman E. Transformation of primary human endothelial cells by Kaposi’s sarcoma-associated herpesvirus. Nature. 1998;394(6693):588–592. doi: 10.1038/29093. - DOI - PubMed
    1. Gao SJ, Deng JH, Zhou FC. Productive lytic replication of a recombinant Kaposi’s sarcoma-associated herpesvirus in efficient primary infection of primary human endothelial cells. J Virol. 2003;77(18):9738–9749. doi: 10.1128/JVI.77.18.9738-9749.2003. - DOI - PMC - PubMed

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