Melatonin inhibits cholangiocarcinoma and reduces liver injury in Opisthorchis viverrini‐infected and N‐nitrosodimethylamine‐treated hamsters

The human liver fluke Opisthorchis viverrini infection and N‐nitrosodimethylamine (NDMA) administration induce cholangiocarcinoma (CCA) and liver injury in hamsters. Melatonin protects against liver injury and reduces the alteration of mitochondrial structure, mitochondrial membrane potential, and mitochondrial pro‐ and anti‐apoptotic pathways in various cancer types. To investigate the chemopreventive effect of melatonin on CCA genesis and liver injury, hamsters were treated with a combination of O. viverrini infection and NDMA concurrently administered with melatonin (10 mg/kg and 50 mg/kg) for 120 days. Melatonin treatment at 50 mg/kg caused a significant reduction in liver/body weight ratios and decreased tumor volumes leading to an increase in the survival of animals. In the tumorous tissues, the high‐dose melatonin reduced DNA fragmentation and mitochondrial apoptosis by inducing anti‐apoptotic protein (Bcl‐2) in the mitochondrial fraction and down‐regulating cytochrome c, pro‐apoptotic protein (Bax), and caspase‐3 in tumor cytosol. Moreover, a high‐dose melatonin treatment significantly increased mitochondrial antioxidant enzymes and prevented mitochondrial ultrastructure changes in the tumor. Overall, melatonin has potent chemopreventive effects in inhibiting CCA genesis and also reduces liver injury in hamster CCA, which, in part, might involve in the suppression of CCA by reducing tumor mitochondria alteration.     

Differential cytotoxic effects of arsenic compounds in human acute promyelocytic leukemia cells

Arsenic trioxide, As₂O₃, has successfully been used to treat acute promyelocytic leukemia (APL). Induction of apoptosis in cancerous cells has been proposed to be the underlying mechanism for the therapeutic efficacy of arsenic. To further understand the cytotoxicity of arsenic compounds in APL cells, HL-60 cells were exposed to graded concentrations of the following arsenicals for up to 48 h: arsenic trioxide (As^III), sodium arsenate (As^V), phenylarsine oxide (PAO^III), monomethylarsonous acid (MMA^III), monomethylarsonic acid (MMA^V) and dimethylarsinic acid (DMA^V), and the viability and modes of cell death assessed. The arsenic-exposed cells were stained with annexin V-PE and 7-aminoactinomycin D (7-AAD) and analyzed by flow cytometry in order to detect apoptotic and viable cells while cell morphology was visualized using scanning and transmission electron microscopy. Acridine orange staining and microtubule-associated protein 1 light chain 3 (MAP-LC3) detection were used to recognize autophagic cell death. The results showed that the compounds reduced viable HL-60 cells by inducing apoptosis in a concentration-dependent manner. None of the compounds tested caused a significant change in binding of acridine orange or redistribution of MAP-LC3. Potencies of the six different arsenic compounds tested were ranked as PAO^III > MMA^III ≥ As^III > As^V > MMA^V > DMA^V. An increase in caspase-3 activity by PAO^III, MMA^III and DMA^V implied that these compounds induced apoptosis in HL-60 cells through a caspase-dependent mechanism, but the other arsenic compounds failed to activate caspase-3, suggesting that they induce apoptosis by an alternative pathway.     

NEGATIVE THINKING: A KEY FACTOR IN DEPRESSIVE SYMPTOMS IN THAI ADOLESCENTS

Negative thinking, self-esteem, parental bonding, and everyday stressors are factors related to depressive symptoms in studies conducted in the United States, but they have been rarely explored in Thailand. An understanding of factors influencing depressive symptoms in Thai youth will lead to the development of interventions to decrease depressive symptoms among this age group. The purpose of this study was to examine the effects of parental bonding, everyday stressors, self-esteem, and negative thinking on depressive symptoms among Thai adolescents. A random sample of 812 high school students in Chon Buri, Thailand, participated in the study. The prevalence of depressive symptoms varied from 20–21% depending on the measures used. Negative thinking was the best predictor of depressive symptoms in Thai adolescents. Negative thinking also mediated the effects of parental bonding, everyday stressors, and self-esteem on depressive symptoms.     

Negative thinking: a key factor in depressive symptoms in Thai adolescents

Negative thinking, self-esteem, parental bonding, and everyday stressors are factors related to depressive symptoms in studies conducted in the United States, but they have been rarely explored in Thailand. An understanding of factors influencing depressive symptoms in Thai youth will lead to the development of interventions to decrease depressive symptoms among this age group. The purpose of this study was to examine the effects of parental bonding, everyday stressors, self-esteem, and negative thinking on depressive symptoms among Thai adolescents. A random sample of 812 high school students in Chon Buri, Thailand, participated in the study. The prevalence of depressive symptoms varied from 20-21% depending on the measures used. Negative thinking was the best predictor of depressive symptoms in Thai adolescents. Negative thinking also mediated the effects of parental bonding, everyday stressors, and self-esteem on depressive symptoms.     

Detection of a known mutation M412T in the LDL receptor in a Chinese Thai FH family

BACKGROUND: Familial hypercholesterolemia (FH) is an autosomal dominant hypercholesterolemia caused by mutation in the LDL receptor gene. M412T mutation of the LDL receptor gene was previously observed in a single female patient diagnosed as having primary hypercholesterolemia. However, the analysis was incomplete and there was no confirmation of the M412T as the FH-causing mutation. We identified a mutation in the LDL receptor gene that underlines the severe FH phenotype in a new case, a female Chinese Thai patient. METHODS: Identification was made by PCR-SSCP, direct DNA sequencing and confirmed by allele specific amplification (ASA) originally designed for this current study. RESULTS: The entire LDL receptor gene screening revealed the genetic alteration that also caused M412T mutation in this new index patient. ASA analysis confirmed the DNA sequence in this patient and further identified three family members as M412T carriers. CONCLUSIONS: The finding of this mutation in 2 apparently unrelated index patients and the co-segregation of M412T and FH phenotype in the family of the present index case should provide evidence and confirm that the M412T was likely to be a disease-causing mutation. Whether M412T is common either as a founder or recurrent mutation among FH Chinese Thai population is unknown at present and remains to be clarified.     

Plasma hydroxyproline, MMP-7 and collagen I as novel predictive risk markers of hepatobiliary disease-associated cholangiocarcinoma

Chronic opisthorchiasis caused by Opisthorchis viverrini infection is characterized by advanced periductal fibrosis leading to hepatobiliary diseases (HBD), including cholangiocarcinoma (CCA). We aimed to determine fibrotic markers to differentiate HBD status including opisthorchiasis, benign biliary disease (BBD) and CCA. Candidate fibrotic markers in plasma of healthy individuals (n = 14) and patients with opisthorchiasis (n = 32, pre- and post-treatment with praziquantel), BBD (n = 31), CCA (n = 37) and other types of tumors (n = 14) were measured by ELISA and zymography. Plasma levels of hydroxyproline (HYP), collagen I, MMP-7 and TIMP2 in opisthorchiasis patients were significantly higher than those in healthy individuals, and MMP9/TIMP2 balance may be associated with tissue resorption after praziquantel treatment. HYP and TIMP-2 levels were significantly correlated with periductal fibrosis status evaluated by ultrasonography. Plasma HYP level of CCA patients was the highest among HBD patients (p < 0.05). ROC curves revealed HYP, MMP-7 and collagen I levels significantly distinguished opisthorchiasis, BBD and CCA (p < 0.001). Odd ratio (OR) analysis demonstrated these markers in opisthorchiasis were predictable for BBD risk (p < 0.05; OR = 28.50, 10.12 and 4.63 for collagen I, MMP-7 and HYP, respectively), and the risk was reduced by praziquantel treatment. Interestingly, only plasma HYP level in BBD was predictable for CCA risk (OR = 3.69; p = 0.020). In conclusion, plasma HYP, collagen I and MMP-7 may be useful as novel predictive markers of opisthorchiasis-related BBD, and HYP may be used as a diagnostic marker for CCA.