ABCG2 Polymorphism rs2231142 and hypothyroidism in metastatic renal cell carcinoma patients treated with sunitinib

Genetic polymorphisms are associated with individual susceptibility to dexmedetomidine

Introduction: Dexmedetomidine (DXM) is widely used as an adjuvant to anesthesia or a sedative medicine, and differences in individual sensitivity to the drug exist. This study aimed to investigate the effect of genetic polymorphisms on these differences. Methods: A total of 112 patients undergoing hand surgery were recruited. DXM 0.5 μg/kg was administered within 10 min and then continuously injected (0.4 μg/kg/h). Narcotrend index, effective dose and onset time of sedation, MAP, and HR were measured. Forty-five single nucleotide polymorphisms (SNPs) were selected for genotype. Results: We observed individual differences in the sedation and hemodynamics induced by DXM. ABCG2 rs2231142, CYP2D6 rs16947, WBP2NL rs5758550, KATP rs141294036, KCNMB1 rs11739136, KCNMA1 rs16934182, ABCC9 rs11046209, ADRA2A rs1800544, and ADRB2 rs1042713 were shown to cause statistically significant (p < 0.05) influence on the individual variation of DXM on sedation and hemodynamics. Moreover, the multiple linear regression analysis indicated sex, BMI, and ADRA2A rs1800544 are statistically related to the effective dose of DXM sedation. Discussion: The evidence suggests that the nine SNPs involved in transport proteins, metabolic enzymes, and target proteins of DXM could explain the individual variability in the sedative and hemodynamic effects of DXM. Therefore, with SNP genotyping, these results could guide personalized medication and promote clinical and surgical management.

Meta-Analysis of ABCG2 and ABCB1 Polymorphisms With Sunitinib-Induced Toxicity and Efficacy in Renal Cell Carcinoma

Background: ABCG2 and ABCB1 are genes related to the pharmacokinetics of sunitinib and have been associated with its toxicity and efficacy. However, the results have been controversial. This study aimed to evaluate the associations of ABCG2 and ABCB1 polymorphisms with sunitinib-induced toxicity and efficacy in renal cell carcinoma (RCC) by meta-analysis. Methods: PubMed, EMBASE, Cochrane Library, and Web of Science were systematically searched for studies investigating the associations of the ABCG2 rs2231142 polymorphism with sunitinib-induced toxicity and the associations of the ABCB1 rs1128503 and ABCB1 rs2032582 polymorphisms with sunitinib-induced toxicity and clinical outcomes. The associations were evaluated by effect size (ES) with 95% confidence intervals (CIs). Results: Eight and five studies were included in the toxicity and efficacy analysis, respectively, including a total of 1081 RCC patients. The ABCG2 rs2231142 A allele was associated with an increased risk of sunitinib-induced thrombocytopenia and hand-foot syndrome (HFS) in Asians (ES = 1.65, 95% CI = 1.15-2.36, p = 0.006; ES = 1.52, 95% CI = 1.02-2.27, p = 0.041). However, the ABCG2 rs2231142 polymorphism was not associated with sunitinib-induced hypertension or neutropenia (ES = 1.09, 95% CI = 0.69-1.73, p = 0.701; ES = 0.87, 95% CI = 0.57-1.31, p = 0.501). Compared with the C allele, the ABCB1 rs1128503 T allele was associated with a decreased risk of sunitinib-induced hypertension but worse progression-free survival (PFS) (ES = 0.44, 95% CI = 0.26-0.77, p = 0.004; ES = 1.36, 95% CI = 1.07-1.73, p = 0.011). There was no significant association between the T allele or C allele of ABCB1 rs1128503 and overall survival (OS) (ES = 0.82, 95% CI = 0.61-1.10, p = 0.184). The ABCB1 rs2032582 T allele was associated with worse PFS than the other alleles (ES = 1.46, 95% CI = 1.14-1.87, p = 0.003), while there was no significant association between the T allele or other alleles and sunitinib-induced hypertension, HFS, or OS (ES = 0.77, 95% CI = 0.46-1.29, p = 0.326; ES = 1.02, 95% CI = 0.65-1.62, p = 0.919; ES = 1.32, 95% CI = 0.85-2.05, p = 0.215). Conclusion: The results indicate that the ABCG2 rs2231142 polymorphism may serve as a predictor of sunitinib-induced thrombocytopenia and HFS in Asians, while the ABCB1 rs1128503 polymorphism may serve as a predictor of sunitinib-induced hypertension, and both the ABCB1 rs1128503 and rs2032582 polymorphisms may serve as predictors of PFS in RCC. These results suggest a possible application of individualized use of sunitinib according to the genetic background of patients.

Polymorphisms in DNA repair pathway genes and ABCG2 gene in advanced colorectal cancer: correlation with tumor characteristics and clinical outcome in oxaliplatin-based chemotherapy

Objective

Multiple factors are involved in oxaliplatin-resistant process in colorectal cancer (CRC) patients including decreased drug accumulation and enhanced capacity to repair and tolerate DNA damage. In the present study, we aimed to assess the impact of six single-nucleotide polymorphisms (SNPs) in DNA repair genes and ABCG2 gene on prognosis in advanced CRC patients treated with oxaliplatin-based chemotherapy.

Methods

In this study, 580 advanced CRC patients were recruited. Six SNPs of DNA repair genes (XPA rs10817938, XPA rs2808668, XPC rs2607775, and WRN rs1346044) and ABCG2 gene (rs2231142 and rs2622621) were genotyped by using the TaqMan assay.

Results

Regarding interaction with environmental factors, ABCG2 rs2231142 and the first-degree family history of cancer and XPC rs2607775 or ABCG2 rs2622621 and lymph node metastases status demonstrated significant interactions. Of these six SNPs, XPA rs10817938 CT/ TT genotypes retained its significant association with longer overall survival (OS) (P=0.008) in CRC patients receiving oxaliplatin-based chemotherapy (n=580). Furthermore, a significantly better impact on the disease-free survival (DFS) (P=0.001) and OS (P<0.0001) was found in ABCG2 rs2231142CA/AA carriers. Furthermore, ABCG2 rs2622621 CG/GG genotype was verified to be an independent poor prognostic factor in DFS (P=0.010) and OS (P=0.030). In the stratification analysis, XPA rs10817938 CT/CC, rs2231142 CA/AA, and rs2622621 CC genotypes of ABCG2 were predictive of significantly better prognosis in the patients with tumor differentiation grade 3 (n=523), clinical stage IV (n=73), or lymph node-positive status (n=557). Additionally, multivariate logistic regression and multiple dimension reduction analysis consistently revealed that the combination of selected SNPs and five known risk factors showed a better prediction prognosis and represented the best model to predict CRC prognosis.

Conclusion

The current data indicated that the XPA gene and ABCG2 gene had significant interaction with environmental factors and prognosis, which could provide a comprehensive understanding of the implications of those SNPs in the prediction of prognosis in advanced CRC patients receiving oxaliplatin-based chemotherapy.