Hematoporphyrin monomethyl ether (HMME) combined with He-Ne laser irradiation is a novel and promising photodynamic therapy (PDT)-induced apoptosis that can be applied in vitro on canine breast cancer cells. However, the exact pathway responsible for HMME-PDT in canine breast cancer cells remains unknown. CHMm cells morphology and apoptosis were analyzed using optical microscope, terminal deoxynucleotidyl transferase dUTP nick end labeling fluorescein staining and DNA ladder assays. Apoptotic pathway was further confirmed by Real-time-polymerase chain reaction and Western blotting assays. Our results showed that HMME-PDT induced significant changes in cell morphology, such as formation of cytoplasmic vacuoles and the gradual rounding of cells coupled with decreased size and detachment. DNA fragmentation and cell death was shown to occur in a time-dependent manner. Furthermore, HMME-PDT increased the activities of caspase-9 and caspase-3, and released cytochrome c from mitochondria into the cytoplasm. HMME-PDT also significantly increased both mRNA and protein levels of Bax and decreased P53 gene expression in a time-dependent manner, while the mRNA and protein expression of Bcl-2 were repressed. These alterations suggest that HMME-PDT induced CHMm cell apoptosis via the mitochondrial apoptosis pathway and had anti-canine breast cancer effects in vitro.
Apoptosis* ; Blotting, Western ; Breast Neoplasms* ; Breast* ; Caspase 3 ; Caspase 9 ; Cell Death ; Cytochromes c ; Cytoplasm ; DNA ; DNA Fragmentation ; DNA Nucleotidylexotransferase ; Ether* ; Fluorescein ; Genes, p53 ; Hematoporphyrins* ; In Vitro Techniques ; Mitochondria ; Photochemotherapy ; RNA, Messenger ; Vacuoles

【Objective】 To explore the relationship between the methylation level of CNR1 and autism spectrum disorder (ASD), in order to provide a theoretical basis for the etiology of ASD. 【Methods】 A case-control study was conducted, recruiting 30 children with ASD from the Child Development and Behavior Research Center of Harbin Medical University and a rehabilitation facility, and 30 matched typically developed children from June 2017 to December 2018. The methylation levels of CNR1 in peripheral blood were measured by the Agena MassArray^® Mass Spectrometry System. A univariate conditional Logistic regression model was used to analyze the potential association between the methylation level of CNR1 and the risk of ASD with adjustment for age, BMI, body fat percentage and body fat. The correlations between the methylation level of CNR1 and the score of Social Responsiveness Scale (SRS) were evaluated by Pearson/Spearman correlation analysis. 【Results】 The methylation levels of the average methylation (t=2.224), CpG_3.4 (Z=2.187), CpG_9.10.11 (t=2.308), and CpG_28.29 (t=2.943) of the CNR1 promoter region in ASD children were significantly higher than controls (P<0.05). The methylation levels of the average methylation (OR=1.117, 95%CI: 1.003 - 1.245), CpG_9.10.11 (OR= 1.072, 95%CI:1.006 - 1.142), and CpG_28.29 (OR=1.078, 95%CI: 1.018 - 1.141) of the CNR1 promoter region were positively correlated with the risk of ASD (P<0.05). The methylation level of CpG_28.29 in ASD children was positively correlated with the scores of social motivation in SRS (r=0.421, P<0.05). 【Conclusions】 The methylation levels of CNR1 in peripheral blood are abnormal in ASD children and might be correlated with the risk of ASD and social function. The underlying mechanism needs to be further explored.