IADR Abstract Archives
Collagen Cross-Linking as a Biomarker for Oral Mucosal Malignant Transformation
Objectives: Collagen cross-linking plays a role in the stiffness of cancerous stroma and progression of oral squamous cell carcinoma (OSCC). This study investigated the expression levels of the enzymes lysyl oxidase (LOX), LOX-like-2 (LOXL2) and collagen crosslinking as biomarkers for oral mucosal malignant transformation.
Methods: Immunohistochemistry staining (IHC) was performed to detect LOX and LOXL2 in human tissue samples of incisional biopsies from OSCC (n=9/enzyme) and normal mucosa (n=3/enzyme). Staining intensity was scored on a scale of 1 (lowest) to 3 (highest), independently, by two investigators and average staining intensity and distribution were reported. ATR-FT-IR (FT-IR- Spectrum Two, PerkinElmer, Waltham, MA, USA) spectra were collected from fully hydrated oral mucosal samples harvested postmortem from mice after consumption of the oral carcinogen 4-nitroquinoline 1-oxide (OSCC; n=12) for 16 weeks, non-cancerous tongue (n=12) and controls (normal tongue; n=8). All spectra were acquired over the range 4000–400cm−1. Area under eight spectral peaks were measured and compared. Data were analyzed by two-way ANOVA (post-hoc Tukey, α=0.05).
Results: IHC revealed high levels of LOX and LOXL2 in tumor samples. ATR-FT-IR analysis showed significant differences at every analyzed peak when comparing tumors from 4NQO treated mice with control tissue (p<0.05) (Figure 1). The changes observed in the Amide I and Amide II peaks at 1640cm-1 and 1548cm-1, respectively, are consistent with increased levels of collagen crosslinking. No significant differences were found between any peaks when comparing non-cancerous tissues from 4NQO treated mice versus normal (p=0.748).
Conclusions: This study suggests that LOX and LOXL2 mediated collagen crosslinking occurs during late stages of OSCC tumorigenesis. Further experimentation must be done to determine the specific timing of collagen crosslinking and its correlation to the pathogenesis of OSCC.
Methods: Immunohistochemistry staining (IHC) was performed to detect LOX and LOXL2 in human tissue samples of incisional biopsies from OSCC (n=9/enzyme) and normal mucosa (n=3/enzyme). Staining intensity was scored on a scale of 1 (lowest) to 3 (highest), independently, by two investigators and average staining intensity and distribution were reported. ATR-FT-IR (FT-IR- Spectrum Two, PerkinElmer, Waltham, MA, USA) spectra were collected from fully hydrated oral mucosal samples harvested postmortem from mice after consumption of the oral carcinogen 4-nitroquinoline 1-oxide (OSCC; n=12) for 16 weeks, non-cancerous tongue (n=12) and controls (normal tongue; n=8). All spectra were acquired over the range 4000–400cm−1. Area under eight spectral peaks were measured and compared. Data were analyzed by two-way ANOVA (post-hoc Tukey, α=0.05).
Results: IHC revealed high levels of LOX and LOXL2 in tumor samples. ATR-FT-IR analysis showed significant differences at every analyzed peak when comparing tumors from 4NQO treated mice with control tissue (p<0.05) (Figure 1). The changes observed in the Amide I and Amide II peaks at 1640cm-1 and 1548cm-1, respectively, are consistent with increased levels of collagen crosslinking. No significant differences were found between any peaks when comparing non-cancerous tissues from 4NQO treated mice versus normal (p=0.748).
Conclusions: This study suggests that LOX and LOXL2 mediated collagen crosslinking occurs during late stages of OSCC tumorigenesis. Further experimentation must be done to determine the specific timing of collagen crosslinking and its correlation to the pathogenesis of OSCC.
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