An Automated Approach to Analyze MMP1 Expression in Oral Squamous Cell Carcinoma Using Fluorescence in Situ Hybridization: An Image Based Analysis.

OBJECTIVES

1.To evaluate matrix metalloproteinase 1 (MMP1) expression in oral squamous cell carcinoma (OSCC) through fluorescence in situ hybridization (FISH). 2. To design an algorithm for the validation of FISH photomicrographs using a computer programming language.

MATERIAL AND

METHODS

The formalin fixed paraffin embedded (FFPE) tissue blocks from 20 histopathologically confirmed cases of OSCC and 24 normal oral mucosal (NOM) samples from healthy volunteers were considered. The inclusion and exclusion criteria were defined. After identifying the probe for MMP1, the protocol was optimized. 4 µm tissue sections were subjected to FISH for MMP1 analysis. The expression was observed manually under fluorescence microscope by two pathologists independently. With computer programme, an algorithm was designed to quantify the data from the microscopic images of FISH-MMP1.

RESULTS

The MMP1 expression was significantly more in OSCC when compared to NOM. The mean scores for staining intensity were significantly higher in OSCC [2.10 ± 0.72] as compared to NOM [1.54 ± 0.66] with p=0.01 and 95%CI [0.14, 0.98]. The ROC curve analysis showed a sensitivity of 80%, specificity of 54.2% and an accuracy of 65.9%. Further, the digital data quantification revealed the precision of the model used, to be 66.67 and recall 82.36, suggesting differential expression of MMP1 between OSCC and normal oral samples.

CONCLUSION

The present study has shown greater expression of MMP1 in OSCC when compared to normal oral mucosal tissues. Further, a simple yet novel digital method to objectively quantify the expression of MMP1 in OSCC has been shown.