Impact of L-type amino acid transporter 1 on intrahepatic cholangiocarcinoma.

BACKGROUND: Amino acid transporters, such as L-type amino acid transporter 1 (LAT1), have an effect on tumor growth, metastasis, and survival of various solid tumors. However, the role of LAT1 in patients with intrahepatic cholangiocarcinoma (IHCC) remains unknown. METHODS: Forty-six patients who had undergone initial hepatic resection for IHCC at Tokushima University Hospital were enrolled in this study. Immunohistochemical analysis of LAT1 and phosphorylated Akt (p-AKT) was performed using resected specimens. Clinicopathological factors, including prognosis, were analyzed between LAT1-high and LAT1-low groups. RESULTS: The LAT1-high group showed a higher proportion of periductal infiltrating type and higher carcinoembryonic antigen/carbohydrate antigen 19-9 levels compared with the LAT1-low group. Multivariate analysis revealed that LAT1-high expression was an independent prognostic factor for disease-free survival. Furthermore, the proportion of p-AKT positivity was higher in the LAT1-high group than in the LAT1-low group. CONCLUSIONS: LAT1 expression was associated with poor prognosis of IHCC and higher p-Akt expression. J. Med. Invest. 70 : 160-165, February, 2023.

Modifying Effect of Smoking on GSTM1 and NAT2 in Relation to the Risk of Bladder Cancer in Mongolian Population: A Case-Control Study.

OBJECTIVES: Tobacco smoking is the predominant risk factor for bladder cancer as it contains cancer-causing chemicals. However, genetic factors may play important role in response towards chemical carcinogens. In this study we aim to investigate genetic polymorphisms of glutathione S-transferase M1 (GSTM1) and N-acetyltransferase 2 (NAT2) as determinants of bladder cancer risk, independently and in combination with tobacco use in the Mongolian population. MATERIALS AND METHODS: The current study was a hospital-based case-control study including 60 histologically confirmed bladder cancer patients and 60 cancer-free controls. PCR-RFLP assay was used to determine the presence of GSTM1 and NAT2 polymorphisms in bladder cancer patients and controls. GSTM1 and NAT2 were tested using binary logistical regression analysis with adjustment or stratification according to the smoking. RESULTS: There were 46 men and 14 women diagnosed with bladder cancer, with mean age was 58±4. The controls included 37 men and 23 women with a mean age of 57±3. The frequency of GSTM1 null genotype was higher in controls (71.67%) than in bladder cancer patients (58.33%) without statistical significance (OR=0.5534; 95% CI=0.2586-1.1843), (p=0.128). The NAT2 low acetylator phenotype was more common in patients with bladder cancer (15%) than in controls (5%). Furthermore, individuals with NAT2 low acetylator phenotype had a nearly 3.35-fold increased risk to develop bladder cancer (OR=3.35; 95% CI=0.8604-13.0657), (p=0.081) while the risk was even higher when combined with null GSTM1 genotype (OR=4; 95% CI=0.4459-37.5308), (p=0.213) but there was no statistical significance. Prevalence of smoking in bladder cancer patients was higher than controls and increased significantly the risk of bladder cancer (OR=8.31; 95% CI=3.66-18.88). Smokers with GSTM1 null genotype were at 5-fold higher risk of bladder cancer (OR=5.0; 95% CI=1.55-16.16), (p=0.007) while NAT2 low acetylator phenotype increased bladder cancer risk by 20-fold (OR=20.5; 95% CI=2.33-80.86), (p=0.006). CONCLUSION: The current study shows that tobacco smokers with the NAT2 low acetylator phenotype and GSTM1 null genotype have the highest risk of bladder cancer in the Mongolian population.
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Association between MDM2-SNP309 and p53R72P polymorphisms and the risk of bladder cancer in the Mongolian population.

The current study aims to investigate whether MDM2-SNP309 and p53R72P polymorphisms were associated with the risk of bladder cancer in Mongolian populations. These polymorphisms were evaluated in 79 controls and 63 bladder cancer cases using a PCR-restriction fragment length polymorphism assay, followed by analysis using multivariate logistic regression model and the Kaplan-Meier model to determine the odds ratio (OR) and age at onset of bladder cancer, respectively. The results revealed that the homozygous (G/G) genotype of MDM2-SNP309 increased the risk of bladder cancer compared to the wild-type (T/T) genotype [OR=1.629; 95% confidence interval (CI)=0.622-4.266] among Mongolians. On the other hand, the homozygous (P/P) genotype of p53R72P tended to protect the population from bladder cancer compared with the wild-type (R/R) genotype (OR=0.445; 95% CI=0.1727-2.147). It also showed that G/G genotype of MDM2-SNP309 increased the risk of bladder cancer when combined with the R/R genotype of p53R72P (OR=3.355; 95% CI=0.3914-28.766). Stratification by smoking and history of chronic urinary tract diseases tended towards increasing the risk association of the G/G (OR=2.3704; 95% CI=0.4308-3.044) and T/G genotypes (OR=5; 95% CI=0.8442-30.4088) of MDM2-SNP309 with bladder cancer, respectively. The protective role of P/P of p53R72P remained following stratification. MDM2-SNP309 and p53R72P were not involved in early age onset of bladder cancer in Mongolian patients. Taken together, MDM2-SNP309 and p53R72P had no significant association with bladder cancer in Mongolian patients. The two SNPs were also not able to predict early age at onset of bladder cancer.