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In vivo quantification of the structural changes of collagens in a melanoma microenvironment with second and third harmonic generation microscopy.

Wu PC, Hsieh TY, Tsai ZU, Liu TM - Sci Rep (2015)

Bottom Line: The corresponding GLCM traces showed oscillation features and the sum of squared fluctuation VarGLCM increased with the tumor sizes.In addition, the THG intensities of the extracellular matrices increased, indicating an enhanced optical inhomogeneity.We believe these indices have the potential to help the diagnosis of skin cancers in clinical practice.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biomedical Engineering, National Taiwan University, Taipei 10617, Taiwan.

ABSTRACT
Using in vivo second harmonic generation (SHG) and third harmonic generation (THG) microscopies, we tracked the course of collagen remodeling over time in the same melanoma microenvironment within an individual mouse. The corresponding structural and morphological changes were quantitatively analyzed without labeling using an orientation index (OI), the gray level co-occurrence matrix (GLCM) method, and the intensity ratio of THG to SHG (RTHG/SHG). In the early stage of melanoma development, we found that collagen fibers adjacent to a melanoma have increased OI values and SHG intensities. In the late stages, these collagen networks have more directionality and less homogeneity. The corresponding GLCM traces showed oscillation features and the sum of squared fluctuation VarGLCM increased with the tumor sizes. In addition, the THG intensities of the extracellular matrices increased, indicating an enhanced optical inhomogeneity. Multiplying OI, VarGLCM, and RTHG/SHG together, the combinational collagen remodeling (CR) index at 4 weeks post melanoma implantation showed a 400-times higher value than normal ones. These results validate that our quantitative indices of SHG and THG microscopies are sensitive enough to diagnose the collagen remodeling in vivo. We believe these indices have the potential to help the diagnosis of skin cancers in clinical practice.

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Related in: MedlinePlus

In vivo SHG imaging of the collagen networks in a normal mouse ear at (a) zone 1, (b) zone 2, (c) zone 3, (d) zone 4, (e) zone 5, (f) zone 6, (g) zone 7, (h) zone 8, and (i) zone 9.Fields of view: 240 μm × 240 μm. These images were acquired for control analysis.
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f4: In vivo SHG imaging of the collagen networks in a normal mouse ear at (a) zone 1, (b) zone 2, (c) zone 3, (d) zone 4, (e) zone 5, (f) zone 6, (g) zone 7, (h) zone 8, and (i) zone 9.Fields of view: 240 μm × 240 μm. These images were acquired for control analysis.

Mentions: Before implanting the melanoma cells in the mice ears, we obtained SHG sectioning images of the collagen fibers in vivo at nine different zones as a normal control (Fig. 4). The way we define the zones is described in the supplementary information. In each zone, we arbitrarily chose three locations for tomographic imaging. At each location, ten sectioning images at different depths were acquired.


In vivo quantification of the structural changes of collagens in a melanoma microenvironment with second and third harmonic generation microscopy.

Wu PC, Hsieh TY, Tsai ZU, Liu TM - Sci Rep (2015)

In vivo SHG imaging of the collagen networks in a normal mouse ear at (a) zone 1, (b) zone 2, (c) zone 3, (d) zone 4, (e) zone 5, (f) zone 6, (g) zone 7, (h) zone 8, and (i) zone 9.Fields of view: 240 μm × 240 μm. These images were acquired for control analysis.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4352861&req=5

f4: In vivo SHG imaging of the collagen networks in a normal mouse ear at (a) zone 1, (b) zone 2, (c) zone 3, (d) zone 4, (e) zone 5, (f) zone 6, (g) zone 7, (h) zone 8, and (i) zone 9.Fields of view: 240 μm × 240 μm. These images were acquired for control analysis.
Mentions: Before implanting the melanoma cells in the mice ears, we obtained SHG sectioning images of the collagen fibers in vivo at nine different zones as a normal control (Fig. 4). The way we define the zones is described in the supplementary information. In each zone, we arbitrarily chose three locations for tomographic imaging. At each location, ten sectioning images at different depths were acquired.

Bottom Line: The corresponding GLCM traces showed oscillation features and the sum of squared fluctuation VarGLCM increased with the tumor sizes.In addition, the THG intensities of the extracellular matrices increased, indicating an enhanced optical inhomogeneity.We believe these indices have the potential to help the diagnosis of skin cancers in clinical practice.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biomedical Engineering, National Taiwan University, Taipei 10617, Taiwan.

ABSTRACT
Using in vivo second harmonic generation (SHG) and third harmonic generation (THG) microscopies, we tracked the course of collagen remodeling over time in the same melanoma microenvironment within an individual mouse. The corresponding structural and morphological changes were quantitatively analyzed without labeling using an orientation index (OI), the gray level co-occurrence matrix (GLCM) method, and the intensity ratio of THG to SHG (RTHG/SHG). In the early stage of melanoma development, we found that collagen fibers adjacent to a melanoma have increased OI values and SHG intensities. In the late stages, these collagen networks have more directionality and less homogeneity. The corresponding GLCM traces showed oscillation features and the sum of squared fluctuation VarGLCM increased with the tumor sizes. In addition, the THG intensities of the extracellular matrices increased, indicating an enhanced optical inhomogeneity. Multiplying OI, VarGLCM, and RTHG/SHG together, the combinational collagen remodeling (CR) index at 4 weeks post melanoma implantation showed a 400-times higher value than normal ones. These results validate that our quantitative indices of SHG and THG microscopies are sensitive enough to diagnose the collagen remodeling in vivo. We believe these indices have the potential to help the diagnosis of skin cancers in clinical practice.

Show MeSH
Related in: MedlinePlus