Photodynamic effect of photoproduct originated in photosensitizer on experimental tongue squamous cell carcinoma in rat

目的：5-氨基乙酰丙酸（ALA）诱导的原卟啉IX（PpIX）已被用作用于口腔癌治疗的光动力疗法（PDT）中的光敏剂。然而，ALA-PDT在口腔病变中的应用仅限于相对早期的恶性肿瘤。Pp-IX在ALA口服给药后在癌细胞的线粒体中产生，并且在635 nm照射附近被最佳激活以诱导恶性病变的光破坏。最近，据报道，在ALA-PDT的照射过程中，形成了几种光产物。光敏原卟啉是主要产物，峰值吸收在670 nm左右，本身就是高效的光敏剂。材料和方法：采用大鼠口腔恶性病变（舌、牙龈、腭粘膜），用635和670 nm光同时照射ALA致敏的病变，观察其对Pp-IX及其光产物的治疗作用。 关于我们 用4-硝基喹啉-1-氧化物（4 NQ 0）诱导的大鼠心肌细胞凋亡，持续6个月。ALA（250 mg/kg）灌胃后4 h，用三种发射波长的半导体激光照射损伤区。三种类型：（1）635 nm CW（80mW/150J）;（635nm）（2）635nm CW（80mW/150J）+ 670nm CW（80mW/ 150J）;（635nm+670nm）（3）635nm CW（80 mW/150 J）+脉冲三波长; 659 nm 664 nm 669 nm（42：7：1）（80mW/150J）;（635nm+PTW）。Ki 67和细胞凋亡（Apoptag）检测每个样品作为治疗evaluation.Conclusion和Discussion：肿瘤活性和细胞凋亡的降低的评估显示，与635 nm单独组和635 nm +670 nm组相比，635 nm + PMW组的疗效。这一结果表明，用635 nm同时照射ALA致敏的癌症并加入光产物光显示出增强的治疗效果。659 nm、664 nm、669 nm对肿瘤的光杀伤作用优于670 nm。少

Purpose: 5-aminolevulinic acid (ALA)-induced protoporphyrinlX (PpIX) has been used as a photosensitizer in photodynamic therapy (PDT) for oral cancer treatment. However, the application of ALA-PDT for oral lesion is limited in relatively early malignant tumor. The Pp-IX is produced in mitochondria of cancer cell after the ALA oral-administration and is activated optimally around 635nm irradiation to induce photodestruction of the malignant lesion. Recently, it is reported that during irradiation of ALA-PDT several photoproducts are formed. Photoprotoporphyrin is the main product with peak absorption around 670nm and is efficient photosensitizer itself. It has therefore been speculated that concomitant irradiation of ALA-sensitized lesions with 635 and adding 670nm light might be more effective in harnessing the therapeutic effects arising from both Pp-IX and its photoproduct.Material and Method: Malignant lesions of rat oral cavity (tongue, gingiva, palatal mucosa) were used in this st … More udy which was induced by 4-nitroquinoline-l-oxide (4NQ0) administration about for 6 months. At 4h after oral administration of ALA (250mg/kg), the lesions were irradiated with three type of emission wavelength of diode laser. Three type were(1) 635nm CW (80mW/150J) ; (635nm)(2) 635nm CW (80mW/150J) + 670nm CW(80mW/ 150J) ; (635nm+670nm)(3) 635nm CW (80mW/150J) +Pulsed Three Wavelengths ; 659nm 664nm 669nm(42 : 7 : 1) (80mW/150J) ; (635nm+PTW).Rats were killed at 24h after laser irradiation and oral cancer samples were excised. Ki67 and apoptosis (Apoptag) were examined immunohistochemically for each samples as treatment evaluation.Conclusion and Discussion: Assessment of decrease of tumor activity and apoptosis revealed efficacy in the 635nm + PMW group compared to 635nm alone group and 635nm+670nm group. This result suggested that concomitant irradiation of ALA-sensitized cancer with 635 nm and adding photoproduct light showed enhancing the therapeutic effects. And it might be considered that 659nm, 664nm 669nm is more effective rather than 670nm.alone for tumor as photodestruction effect of photoproduct. Less