br Lung and tumor kinetics of cationic
Lung and tumor kinetics of cationic lipoplexes in mice
Characterization of siRNA-loaded cationic lipoplexes.
Formulation Hydrodynamic Diameter (nm) Polydispersity Index Zeta Potential (mV) Entrapment Efficiency (%)
Lipoplexes were prepared with the phospholipids DPPC, DOTAP, and DSPE-PEG (2000) at an optimized lipid/siRNA (N/P) ratio of 2.6:1. Lipoplexes were dispersed in HEPES-buffered deionized water (pH 7–7.4) and characterized on the basis of size (nm), polydispersity, surface charge (mV) and entrapment efficiency (%). Results represent mean with standard deviation.
Cationic lipoplexes loaded with SOX2 siRNA (CL-siSOX2) reverse tumor growth in mice
Cationic lipoplexes encapsulating SOX2 siRNA (CL-siSOX2) were effective in inducing tumor regression in both
Figure 2. Fluorescent cationic lipoplexes (fCL) are efficient in trafficking to lung and xenograft tumor tissue in mice. DiR-labeled lipoplexes (fCL) were administered into C.B.17 SCID mice bearing H1650 SP as xenograft tumors. Distribution kinetics (A) tumor and (B) organs were determined on the basis of fluorescence intensity (perfusion/sec) using the Carestream Molecular Imaging In-Vivo MS FX PRO (Bruker). Statistical analysis: **P = 0.0020 and ***P = 0.0003.
orthotopic and xenograft tumors in mice after single treatment or combination with cisplatin (Figure 3, A). Figure 3, B shows mice body weight measurements over the total treatment course with a significant decrease in body weight observed in cisplatin group compared to CL-siScr and CL-siSOX2 groups at day 8; all mice in the cisplatin group were sacrificed on day 8 due to significant loss in body weight (25.88%) and a general observation of emaciation and distress. Although, body weight in the CL-siSOX2 + cisplatin group decreased by 12.94% (day 8), 22.35% (day 13) and 25.88% (day 15), animals did not exhibit the distress observed in the cisplatin group. Notwithstanding, tumor volume reduction (% baseline) in the cisplatin group at day 8 (38.31 ± 29.92%) was comparable to that observed in CL-siSOX2 and CL-siSOX2 + cisplatin at day 8 (35.97 ± 25.97% and 31.28 ± 22.47% respectively), with the tumor in the latter two groups decreasing further on day 11 (38.90 ± 26.08% and
CL-siSOX2 inhibits 217075-36-0 of stemness markers in xenograft tumors
CL-siSOX2 inhibits expression of markers of multidrug resistance in xenograft tumors
CL-siSOX2 inhibits expression of markers invasion and metastasis in xenograft tumors
Figure 3. Cationic lipoplexes encapsulating SOX2 siRNA (CL-siSOX2) inhibit lung tumor growth in orthotopic and xenograft mice models. C.B.17 SCID-beige mice were injected (A) orthotopically (left panel) or subcutaneously (right panel) with H1650 SP cells as described under materials and methods. Animals received (a) CL-siScr, (b) cisplatin (2 mg/kg; i.p., on day 1 and 6), (c) CL-siSOX2 (22 nmol/100 μL; i.p. for 6 days on alternate days) and (d) CL-siSOX2 + cisplatin. Mice were sacrificed and orthotopic and xenograft lung tumors resected. Micrographs of orthotopic tumors are shown as either nodular (thick black outlines) or areas of sparsely disseminated (broken black lines) groups. (B-D) H1659 SP-derived xenograft tumors in C.B.17 SCID-beige mice were allowed to grow to approximately 150 mm3 in diameter followed by treatment as described above. Mice body weight (B), tumor volume (C) and tumor weight
(D) were determined and presented as mean with standard deviation. (D) represents endpoint data at day 15 of treatment except for the cisplatin group; animals in the cisplatin group were sacrificed at day 8 due to increased distress. (E) Immunohistochemical staining for SOX2, E-cadherin and N-cadherin, and (F) H&E staining were performed on resected lung tissue and images were captured by light microscopy. Statistical analysis: student t test: (treatment vs. siScr: *P b 0.05; **P b 0.01; ****P b 0.0001, and treatment vs. cisplatin: ##P b 0.01).
Figure 4. Cationic lipoplex loaded with siSOX2 (CL-siSOX2) inhibit expression of stemness markers in mice xenograft tumors. C.B.17 SCID mice with H1650 SP cells as tumor xenografts received treatment as described. (A) Immunoblotting of tumor lysates show knockdown of (B) SOX2 and associated stemness factors including (C) OCT4, (D) Nanog, (F) KLF4, as well as the oncogene (E) c-Myc. Results were calculated as protein/β-actin ratio and presented as mean percent of the CL-siScr with SD. Statistical analysis: student t test: (treatment vs. siScr: **P b 0.01; ***P b 0.001; ****P b 0.0001, treatment vs. cisplatin:
CL-siSOX2 inhibits expression markers of inflammation in xenograft tumors