Abstract
[Background and Purpos]Despite recent improvements in surgical techniques and adjuvant therapies, the prognosis of patients with advanced esophageal cancer remains poor. Esophageal squamous cell carcinoma (ESCC) has high sensitivity for radiation and chemotherapy compared with other cancer of the digestive system. The purpose of this study was to elucidate the involvement of CDDP in ESCC using in air-micro PIXE (Particle Induced X-ray Emission).[Materials and method]Two human ESCC cell lines–TE-2 and TE-13–were examined for their response to CDDP. ESCC cells were treated various concentrations of CDDP, and we examined sensibility of cisplatin using MTT assay. We also performed real-time RT-PCR to evaluate the mRNA expression of multidrug resistant molecule in both cell lines. Dynamic state of element and intracellular metabolism were measured in CDDP treated cancer cells using air PIXE. Imaging data of individual cancer cell was captured in detail using this method. [Results]TE-2 cells were more highly sensitive to CDDP than TE-13 cells. The mRNA expressions of multidrug resistant molecules were differed between TE-2 and TE-13. Using air PIXE we observed distribution of P and K were localized at cytoplasm, and Br was localized at nuclear site. Air PIXE may be one of the new methods to measure CDDP combined with existing methods. [Discussion and Perspective]Intracellular concentration of Pt was measured using air PIXE, unfortunately we cannot confirm the difference of distribution of intranuclear Pt in two cells at this moment. Air PIXE may have role in application to predict CDDP sensitivity in cancer cells. Our results using air PIXE has limitation, since it only can be presented by the imaging semi quantitative data. Future study will be needed to establish a new method for precise quantitative data.
