The luminance ratio of autofluorescence in a xenograft mouse model is stable through tumor growth stages

Abstract

The aim of this research was to investigate the value of autofluorescence imaging of oral cancer across different stages of tumor growth, to assist in detecting tumors. A xenograft mouse model was created with human oral squamous cell carcinoma cell line HSC‐3 being subcutaneously inoculated into nude mice. Tumor imaging was performed with an autofluorescence imaging method (Illumiscan®) using the luminance ratio, which was defined as the luminance of the tumor site over the luminance of normal skin tissue normalized to a value of 1.0. This luminance ratio was continuously observed postinoculation. Tumor and normal skin tissues were harvested, and differences in the concentrations of flavin adenine dinucleotide and nicotinamide adenine dinucleotide were examined. The luminance ratio of the tumor sites was 0.85 ± 0.05, and there was no significant change in the ratio over time, even if the tumor proliferated and expanded. Furthermore, flavin adenine dinucleotide and nicotinamide adenine dinucleotide were significantly lower in tumor tissue than in normal skin tissue. A luminance ratio under 0.90 indicates a high possibility of tumor, irrespective of the tumor growth stage. However, this cutoff value was determined using a xenograft mouse model and therefore requires further validation before being used in clinical diagnosis.

A control theoretic three timescale model for analyzing energy management in mammalian cancer cells

“…10 D) indicates successful incorporation of slow oxidative phosphorylation [50] into the proposed model. An in vivo / in vitro experiment, performed by Sumi et al [103] depicting lower concentration of NADH ( Fig. 10 C) in cancer cells compared to normar ones, supports the computational result.…”

“… It depicts: (A) Higher expression level of HIF-1 measured in human hepatocellular carcinoma (HCC) specimens compared to the non-cancerous tissue specimens [54] , (B) Similar behavior of HIF-1 expression shown by our simulation results, (C) Lower concentration of NADH in cancer cells compared to normar ones as per the in vivo / in vitro experiment performed by Sumi et al [103] , (D) Similar behavior of NADH depicted by our computational results. …”

Autofluorescence imaging for recurrence detection in skin cancer postoperative scars

“…Autofluorescence (luminance) ratio has been estimated in a very similar way as in our study, dividing luminance of the tumor site over the luminance of adjacent non‐cancerous tissue in G spectral band. Within 1 month of experimental tumor growth (attaining a volume of ~300 mm 3 ) no changes in the autofluorescence ratio were observed in the presence of tumor . For comparison, we report the significant autofluorescence increase associated with the age of the scar (Figure ), therefore scar autofluorescence ratio in situ persisting constant at longer times post scar resection could also indicate the potential malignancy.…”

“…In regard to Figure , examining the scars with recurrent cancer to explore the experimental relationship more precisely between the loss of scar autofluorescence over time and possible cases of cancer recurrence remains an important future objective. For comparison, a study conducted by Sumi et al estimated the loss of green autofluorescence over time in mice xenograft model with human oral SCC. Autofluorescence (luminance) ratio has been estimated in a very similar way as in our study, dividing luminance of the tumor site over the luminance of adjacent non‐cancerous tissue in G spectral band.…”

Development of a Robust Autofluorescence Lifetime Sensing Method for Use in an Endoscopic Application

“…For the preliminary experiment to verify the proposed technique, a phantom mimicking the shape, optical characteristics, and flavin adenine dinucleotide (FAD) concentration distribution of the cancerous tissue [19] is prepared. FAD is a well-known autofluorescence chromophore, and the FAD autofluorescence can indicate the difference in metabolism between the normal and abnormal cells.…”