Limits...
Synthesis and investigation of a radioiodinated F3 peptide analog as a SPECT tumor imaging radioligand.

Bhojani MS, Ranga R, Luker GD, Rehemtulla A, Ross BD, Van Dort ME - PLoS ONE (2011)

Bottom Line: For this purpose, we custom synthesized a modified F3 peptide analog (F3Cys) incorporating a C-terminal cysteine residue for site-specific attachment of a radioiodinated maleimide conjugating group.These results were also confirmed by ex vivo tissue analysis.No-carrier-added [(125)I]IBMF3 was synthesized by a radioiododestannylation approach in 73% overall radiochemical yield.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, United States of America.

ABSTRACT
A radioiodinated derivative of the tumor-homing F3 peptide, (N-(2-{3-[(125)I]Iodobenzoyl}aminoethyl)maleimide-F3Cys peptide, [(125)I]IBMF3 was developed for investigation as a SPECT tumor imaging radioligand. For this purpose, we custom synthesized a modified F3 peptide analog (F3Cys) incorporating a C-terminal cysteine residue for site-specific attachment of a radioiodinated maleimide conjugating group. Initial proof-of-concept Fluorescence studies conducted with AlexaFluor 532 C(5) maleimide-labeled F3Cys showed distinct membrane and nuclear localization of F3Cys in MDA-MB-435 cells. Additionally, F3Cys conjugated with NIR fluorochrome AlexaFluor 647 C(2) maleimide demonstrated high tumor specific uptake in melanoma cancer MDA-MB-435 and lung cancer A549 xenografts in nude mice whereas a similarly labeled control peptide did not show any tumor uptake. These results were also confirmed by ex vivo tissue analysis. No-carrier-added [(125)I]IBMF3 was synthesized by a radioiododestannylation approach in 73% overall radiochemical yield. In vitro cell uptake studies conducted with [(125)I]IBMF3 displayed a 5-fold increase in its cell uptake at 4 h when compared to controls. SPECT imaging studies with [(125)I]IBMF3 in tumor bearing nude mice showed clear visualization of MDA-MB-435 xenografts on systemic administration. These studies demonstrate a potential utility of F3 peptide-based radioligands for tumor imaging with PET or SPECT techniques.

Show MeSH

Related in: MedlinePlus

In vitro and in vivo optical imaging using Fluorescent-labeled F3Cys peptides.MDA-MB-435 cells, in optically clear bottom dishes, cultured in either serum free or serum containing media were stained with AF532-F3Cys, counterstained with DAPI and monitored under a fluorescent microscope (A). Mice bearing MDA-MB-435 (B) or A549 (C) xenografts were injected i.v. via the tail vein with either AF647-F3Cys (1b) or AF647-Control peptide (2). Fluorescence images were acquired over time and a representative image obtained at 2 h is shown (B and C). Ex vivo fluorescence imaging of tumor, kidney and liver harvested 2 h after AF647-F3Cys peptide injection in animals bearing A549 tumor xenograft (D).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3139646&req=5

pone-0022418-g002: In vitro and in vivo optical imaging using Fluorescent-labeled F3Cys peptides.MDA-MB-435 cells, in optically clear bottom dishes, cultured in either serum free or serum containing media were stained with AF532-F3Cys, counterstained with DAPI and monitored under a fluorescent microscope (A). Mice bearing MDA-MB-435 (B) or A549 (C) xenografts were injected i.v. via the tail vein with either AF647-F3Cys (1b) or AF647-Control peptide (2). Fluorescence images were acquired over time and a representative image obtained at 2 h is shown (B and C). Ex vivo fluorescence imaging of tumor, kidney and liver harvested 2 h after AF647-F3Cys peptide injection in animals bearing A549 tumor xenograft (D).

Mentions: When MDA-MB-435 cells were grown in media containing 10% serum and stained with AF532-F3Cys, cell surface and nuclear staining of F3Cys was observed. On the other hand, serum starved cells showed predominantly nuclear staining without significant membrane staining suggesting that F3Cys localizes to cell surface in actively growing cells (Figure 2A). This pattern of staining has been previously demonstrated for F3 peptide and corresponds to the subcellular distribution of nucleolin in serum-starved as well as proliferating cells [3].


Synthesis and investigation of a radioiodinated F3 peptide analog as a SPECT tumor imaging radioligand.

Bhojani MS, Ranga R, Luker GD, Rehemtulla A, Ross BD, Van Dort ME - PLoS ONE (2011)

In vitro and in vivo optical imaging using Fluorescent-labeled F3Cys peptides.MDA-MB-435 cells, in optically clear bottom dishes, cultured in either serum free or serum containing media were stained with AF532-F3Cys, counterstained with DAPI and monitored under a fluorescent microscope (A). Mice bearing MDA-MB-435 (B) or A549 (C) xenografts were injected i.v. via the tail vein with either AF647-F3Cys (1b) or AF647-Control peptide (2). Fluorescence images were acquired over time and a representative image obtained at 2 h is shown (B and C). Ex vivo fluorescence imaging of tumor, kidney and liver harvested 2 h after AF647-F3Cys peptide injection in animals bearing A549 tumor xenograft (D).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3139646&req=5

pone-0022418-g002: In vitro and in vivo optical imaging using Fluorescent-labeled F3Cys peptides.MDA-MB-435 cells, in optically clear bottom dishes, cultured in either serum free or serum containing media were stained with AF532-F3Cys, counterstained with DAPI and monitored under a fluorescent microscope (A). Mice bearing MDA-MB-435 (B) or A549 (C) xenografts were injected i.v. via the tail vein with either AF647-F3Cys (1b) or AF647-Control peptide (2). Fluorescence images were acquired over time and a representative image obtained at 2 h is shown (B and C). Ex vivo fluorescence imaging of tumor, kidney and liver harvested 2 h after AF647-F3Cys peptide injection in animals bearing A549 tumor xenograft (D).
Mentions: When MDA-MB-435 cells were grown in media containing 10% serum and stained with AF532-F3Cys, cell surface and nuclear staining of F3Cys was observed. On the other hand, serum starved cells showed predominantly nuclear staining without significant membrane staining suggesting that F3Cys localizes to cell surface in actively growing cells (Figure 2A). This pattern of staining has been previously demonstrated for F3 peptide and corresponds to the subcellular distribution of nucleolin in serum-starved as well as proliferating cells [3].

Bottom Line: For this purpose, we custom synthesized a modified F3 peptide analog (F3Cys) incorporating a C-terminal cysteine residue for site-specific attachment of a radioiodinated maleimide conjugating group.These results were also confirmed by ex vivo tissue analysis.No-carrier-added [(125)I]IBMF3 was synthesized by a radioiododestannylation approach in 73% overall radiochemical yield.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, United States of America.

ABSTRACT
A radioiodinated derivative of the tumor-homing F3 peptide, (N-(2-{3-[(125)I]Iodobenzoyl}aminoethyl)maleimide-F3Cys peptide, [(125)I]IBMF3 was developed for investigation as a SPECT tumor imaging radioligand. For this purpose, we custom synthesized a modified F3 peptide analog (F3Cys) incorporating a C-terminal cysteine residue for site-specific attachment of a radioiodinated maleimide conjugating group. Initial proof-of-concept Fluorescence studies conducted with AlexaFluor 532 C(5) maleimide-labeled F3Cys showed distinct membrane and nuclear localization of F3Cys in MDA-MB-435 cells. Additionally, F3Cys conjugated with NIR fluorochrome AlexaFluor 647 C(2) maleimide demonstrated high tumor specific uptake in melanoma cancer MDA-MB-435 and lung cancer A549 xenografts in nude mice whereas a similarly labeled control peptide did not show any tumor uptake. These results were also confirmed by ex vivo tissue analysis. No-carrier-added [(125)I]IBMF3 was synthesized by a radioiododestannylation approach in 73% overall radiochemical yield. In vitro cell uptake studies conducted with [(125)I]IBMF3 displayed a 5-fold increase in its cell uptake at 4 h when compared to controls. SPECT imaging studies with [(125)I]IBMF3 in tumor bearing nude mice showed clear visualization of MDA-MB-435 xenografts on systemic administration. These studies demonstrate a potential utility of F3 peptide-based radioligands for tumor imaging with PET or SPECT techniques.

Show MeSH
Related in: MedlinePlus