Mihoko Sugishita

Genetic polymorphisms associated with oxaliplatin-induced peripheral neurotoxicity in Japanese patients with colorectal cancer.

OBJECTIVE Pharmacogenomic associations between severe oxaliplatininduced chronic peripheral neurotoxicity (OXCPN) (Grade 2 lasting for > 7 days or Grade 3) and 9 single nucleotide polymorphisms (SNPs) in 8 genes (TAC1, FOXC1, ITGA1, ACYP2, DLEU7, BTG4, CAMK2N1, and FARS2) were reported by the genomewide association study (GWAS) in Korean patients. The present study was designed to explore reliable predictors of OXCPN and thereby improve the management of metastatic colorectal cancer (CRC). METHODS We retrospectively investigated pharmacogenomic characteristics of OXCPN in 70 Japanese patients with CRC who received oxaliplatin-based chemotherapy and updated the results of our previous analysis of ERCC1 (C118T, rs11615 and C8092A, rs3212986) and GSTP1 (Ile105Val, rs1695) polymorphisms. RESULTS Univariate analysis suggested potential associations of severe OXCPN with rs843748 in ACYP2 and rs17140129 in FARS2, as well as with the absence of diabetes mellitus (DM) (p = 0.056, 0.072, and 0.029, respectively). There was no association between severe OXCPN and any of the 7 other SNPs. Multiple logistic regression analysis showed that an increased risk of severe OXCPN was related to rs17140129 and the absence of DM (p = 0.034 and 0.030, respectively). On updated analysis, polymorphisms of ERCC1 (C118T, rs11615) and rs10486003 in TAC1 were associated with time to the onset of Grade 1 OXCPN (p = 0.024 and 0.049, respectively). CONCLUSIONS Severe OXCPN is significantly related to rs17140129, found in the GWAS of Korean patients, in Japanese patients. Patients without DM are more likely to have OXCPN. The association between ERCC1 polymorphism and time to the onset of OXCPN was significant on updated analysis.

Association between severe toxicity of nilotinib and UGT1A1 polymorphisms in Japanese patients with chronic myelogenous leukemia.

BackgroundNilotinib is a BCR-ABL kinase inhibitor approved for the treatment of Philadelphia chromosome-positive chronic myelogenous leukemia (CML). The UDP-glucuronosyltransferase 1A1 (UGT1A1) polymorphism UGT1A1*28 (*28)/*28 has been linked to an increased risk of hyperbilirubinemia in patients with CML who receive nilotinib. Beside *28, UGT1A1*6 (*6) is another important variant allele in Japanese patients because it is associated with adverse events of irinotecan, metabolized by UGT1A1. We retrospectively investigated the association between severe toxicity of nilotinib and UGT1A1 polymorphisms (*6 and*28) in Japanese patients with CML.Patients and methodsEight patients with cytogenetically confirmed CML who were receiving nilotinib were studied to explore the association of UGT1A1 polymorphisms with severe nilotinib-related toxicity. Genotyping analyses were determined for *6 and *28.ResultsAll 3 patients with the *6/*6 or *6/*28 genotype had severe toxicity, including QT interval prolongation (grade 3), elevated lipase levels (grade 3) plus hyperbilirubinemia (grade 2), and anemia (grade 3) plus hepatic cyst hemorrhage (grade 2) in 1 patient each. Among the 5 patients with the *6/*1 or *1/*1 genotype, 1 had elevated lipase levels (grade 3) and another had severe pain in the lower extremities (grade 3).ConclusionThese findings suggest that UGT1A1 polymorphisms are important determinants of severe toxicity of nilotinib in Japanese patients.

Role of Sphingosine-1-Phosphate in β-adrenoceptor Desensitization via Ca2+ Sensitization in Airway Smooth Muscle

BACKGROUND The correlation between inflammatory cells and airway smooth muscle plays fundamental roles in the pathophysiology of asthma. This study was designed to determine whether pre-exposure of airway smooth muscle to sphingosine-1-phosphate (S1P), which is released from mast cells by allergic reactions, causes a deterioration of β-adrenoceptor function. METHODS Isometric tension and the ratio of fluorescence intensities at 340 and 380 nm (F(340)/F(380)), an indicator of intracellular Ca2+ levels, were simultaneously measured using fura-2 loaded guinea-pig tracheal tissues. Intracellular cAMP levels were also measured. RESULTS Pre-exposure to S1P caused a reduction in the inhibitory effects of 0.3μM isoprenaline, a β-adrenoceptor agonist, and 10μM forskolin, a direct activator of adenylyl cyclase, against 1μM methacholine-induced contraction in concentration- and time- dependent manners. In contrast, the values of F(340)/F(380) were not augmented under this experimental condition. After incubation with S1P in the presence of 0.001-1μM Y-27632, a Rho-kinase inhibitor, the reduced responsiveness to forskolin induced by S1P was reversed in a concentration-dependent manner. Moreover, pre-treatment with pertussis toxin (PTX), an inhibitor of G(i), suppressed the loss of forskolin-induced relaxation induced by S1P. Pre-exposure to S1P markedly inhibited the augmentation of cAMP accumulation induced by forskolin. However, addition of Y-27632 and pre-exposure to PTX returned forsokin-induced cAMP accumulation to the control level. CONCLUSIONS Pre-exposure to S1P causes heterologus desensitization of β-adrenoceptors by increasing the sensitivity of airway smooth muscle to intracellular Ca2+. Ca2+ sensitization regulated by G(i) and Rho-kinase is involved in this phenomenon.

Efficacy of Prophylactic Treatment for Oxycodone‐Induced Nausea and Vomiting Among Patients with Cancer Pain (POINT): A Randomized, Placebo‐Controlled, Double‐Blind Trial

BACKGROUND Although opioid-induced nausea and vomiting (OINV) often result in analgesic undertreatment in patients with cancer, no randomized controlled trials have evaluated the efficacy of prophylactic antiemetics for preventing OINV. We conducted this randomized, placebo-controlled, double-blind trial to evaluate the efficacy and safety of prophylactic treatment with prochlorperazine for preventing OINV. MATERIALS AND METHODS Cancer patients who started to receive oral oxycodone were randomly assigned in a 1:1 ratio to receive either prochlorperazine 5 mg or placebo prophylactically, given three times daily for 5 days. The primary endpoint was the proportion of patients who had a complete response (CR) during the 120 hours of oxycodone treatment. CR was defined as no emetic episode and no use of rescue medication for nausea and vomiting during 5 days. Key secondary endpoints were the proportion of patients with emetic episodes, proportion of patients with moderate or severe nausea, quality of life, and proportion of treatment withdrawal. RESULTS From November 2013 through February 2016, a total of 120 patients were assigned to receive prochlorperazine (n = 60) or placebo (n = 60). There was no significant difference in CR rates (69.5% vs. 63.3%; p = .47) or any secondary endpoint between the groups. Patients who received prochlorperazine were more likely to experience severe somnolence (p = .048). CONCLUSION Routine use of prochlorperazine as a prophylactic antiemetic at the initiation of treatment with opioids is not recommended. Further research is needed to evaluate whether other antiemetics would be effective in preventing OINV in specific patient populations. IMPLICATIONS FOR PRACTICE Prophylactic prochlorperazine seems to be ineffective in preventing opioid-induced nausea and vomiting (OINV) and may cause adverse events such as somnolence. Routine use of prophylactic prochlorperazine at the initiation of treatment with opioids is not recommended. Further research is needed to evaluate whether other antiemetics would be effective in preventing OINV in specific patient populations.