Figure 1.

Vanadate Enhances VSVΔ51 Infection in Cancer Cells but Not Normal Cells

(A) Structure of vanadate ion present at pH 7.4. (B–F and H) Resistant 786-0 human renal cancer cells were pre-treated with vanadate for 4 hr and subsequently infected with (B–E and H) VSVΔ51 (MOI, 0.01 [150 μM]), (B) measles (MOI, 0.01 [100 μM]), (B) sindbis (MOI, 10 [150 μM]), (B) HSV (MOI, 0.01 [150 μM]), (B) vaccinia (MOI, 0.01 [200 μM]). (B and C) Corresponding viral titers were determined 24 (VSVΔ51) or 48 (measles, sindbis, HSV, vaccinia) hr post-infection (hpi) from supernatants. (B, G, and H) n = 3; error bars indicate SEM; t test; NS, no statistical significance; **p < 0.001; as compared to the untreated condition counterparts; (C) n = 3; significance enhancement at 100–200 μm; p < 0.0001 by one-way ANOVA; as compared to 0 μm condition). (D) Twenty-four hours post-infection, fluorescent and phase contrast images were taken of the 786-0 cells treated with mock or 200 μM of vanadate. (E) Multi-step and (F) single-step growth curve of 786-0 pre-treated with vanadate and infected with VSVΔ51 (E) MOI 0.01 or (F) MOI 3; supernatants were tittered by plaque assay (n = 3; significant enhancement at 50–200 μm at indicated time; NS, no statistical significance; **p < 0.001, ***p < 0.0001 by two-way ANOVA; as compared to mock condition). (G) Twenty-four hours post-infection, RNA was collected from 786-0 and CT26WT, and expression of VSV-M gene was quantified by qPCR. (H) Normal cell line GM38 was pre-treated as in (B) infected with VSVΔ51. Corresponding viral titers were determined 24 hpi from supernatants. (I) CT26WT and DBT tumor cores and BALB/c mouse spleen, muscle, lung, and brain tissue cores were pre-treated with 300 μM of vanadate for 4 hr and subsequently infected with 1 × 10⁴ PFU of VSVΔ51 expressing GFP. Twenty-four hours post-infection, fluorescent images were acquired of the tumor and normal tissue cores. Representative images from each triplicate set are shown.