Effect of Zinc-Deficient Diet on Two Strains of Mice.

Zinc (Zn) deficiency is one of the most common nutritional deficiencies worldwide. It is associated with reduced nutritional status and has been reported in cases of growth retardation, alopecia, and decreased serum alkaline phosphatase (ALP). It has also been reported to occur during total parenteral nutrition (TPN) administration and is associated with various diseases, such as liver diseases, diabetes, and kidney disease. We used Zn-deficient mice of ICR and C57BL/6J strains to investigate the various effects of Zn deficiency on the body, assuming that a healthy person may also become deficient in Zn either due to an unbalanced diet or malabsorption. The results showed that a Zn-deficient diet suppressed body weight gain and increased the tissue weight of the kidneys and cecum in both strains of mice. Biochemical data showed no decrease in serum ALP activity in either strain. Furthermore, in C57BL/6J mice, a Zn-deficient diet caused alopecia, loss of villi in the small intestine, and eventually affected the intestinal mucosa, which could be a risk factor for poor nutritional status. Although previous reports have shown that serum ALP activity is decreased during Zn deficiency, this is the first study that used 4-wk-old mice of ICR and C57BL/6J strains to show that serum ALP activity, which is a Zn deficiency marker, did not decrease in the two strains of Zn-deficient mice; furthermore, a Zn-deficient diet causes various symptoms.

A Drosophila toolkit for HA-tagged proteins unveils a block in autophagy flux in the last instar larval fat body.

For in vivo functional analysis of a protein of interest (POI), multiple transgenic strains with a POI that harbors different tags are needed but generation of these strains is still labor-intensive work. To overcome this, we have developed a versatile Drosophila toolkit with a genetically encoded single-chain variable fragment for the HA epitope tag: 'HA Frankenbody'. This system allows various analyses of HA-tagged POI in live tissues by simply crossing an HA Frankenbody fly with an HA-tagged POI fly. Strikingly, the GFP-mCherry tandem fluorescent-tagged HA Frankenbody revealed a block in autophagic flux and an accumulation of enlarged autolysosomes in the last instar larval and prepupal fat body. Mechanistically, lysosomal activity was downregulated at this stage, and endocytosis, but not autophagy, was indispensable for the swelling of lysosomes. Furthermore, forced activation of lysosomes by fat body-targeted overexpression of Mitf, the single MiTF/TFE family gene in Drosophila, suppressed the lysosomal swelling and resulted in pupal lethality. Collectively, we propose that downregulated lysosomal function in the fat body plays a role in the metamorphosis of Drosophila.

Discovery of DS68702229 as a Potent, Orally Available NAMPT (Nicotinamide Phosphoribosyltransferase) Activator.

Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the rate-limiting step of the nicotinamide adenine dinucleotide (NAD+) salvage pathway. Because NAD+ plays a pivotal role in energy metabolism and boosting NAD+ has positive effects on metabolic regulation, activation of NAMPT is an attractive therapeutic approach for the treatment of various diseases, including type 2 diabetes and obesity. Herein we report the discovery of 1-(2-phenyl-1,3-benzoxazol-6-yl)-3-(pyridin-4-ylmethyl)urea 12c (DS68702229), which was identified as a potent NAMPT activator. Compound 12c activated NAMPT, increased cellular NAD+ levels, and exhibited an excellent pharmacokinetic profile in mice after oral administration. Oral administration of compound 12c to high-fat diet-induced obese mice decreased body weight. These observations indicate that compound 12c is a promising anti-obesity drug candidate.

Suppression of Vps13 adaptor protein mutants reveals a central role for PI4P in regulating prospore membrane extension.

Vps13 family proteins are proposed to function in bulk lipid transfer between membranes, but little is known about their regulation. During sporulation of Saccharomyces cerevisiae, Vps13 localizes to the prospore membrane (PSM) via the Spo71-Spo73 adaptor complex. We previously reported that loss of any of these proteins causes PSM extension and subsequent sporulation defects, yet their precise function remains unclear. Here, we performed a genetic screen and identified genes coding for a fragment of phosphatidylinositol (PI) 4-kinase catalytic subunit and PI 4-kinase noncatalytic subunit as multicopy suppressors of spo73Δ. Further genetic and cytological analyses revealed that lowering PI4P levels in the PSM rescues the spo73Δ defects. Furthermore, overexpression of VPS13 and lowering PI4P levels synergistically rescued the defect of a spo71Δ spo73Δ double mutant, suggesting that PI4P might regulate Vps13 function. In addition, we show that an N-terminal fragment of Vps13 has affinity for the endoplasmic reticulum (ER), and ER-plasma membrane (PM) tethers localize along the PSM in a manner dependent on Vps13 and the adaptor complex. These observations suggest that Vps13 and the adaptor complex recruit ER-PM tethers to ER-PSM contact sites. Our analysis revealed that involvement of a phosphoinositide, PI4P, in regulation of Vps13, and also suggest that distinct contact site proteins function cooperatively to promote de novo membrane formation.

Spatiogenetic characterization of S receptor kinase (SRK) alleles in naturalized populations of Raphanus sativus L. var. raphanistroides on Yakushima island.

In various coastal areas of Japan, naturalized radish populations are observed. Radish is a cruciferous plant and exhibits self-incompatibility, involving a system controlled by a single locus with multiple S alleles. Although the S allele diversity of radish cultivars and wild radishes has been characterized, the S allele distribution in naturalized populations has not yet been analyzed in relation to the positions of the plants in situ. Here, we show the S allele distribution in naturalized radish populations of Yakushima, a small island in the East China Sea, with positions of the plants. Radish plants were sampled in coastal areas in Yakushima, and their S alleles were detected and characterized. Most of the S alleles had been previously identified in radish cultivars. However, four novel S alleles, which may be unique to Yakushima, were also found. Moreover, seeds in siliques from plants growing in the study areas were sampled, and S allele determination in DNA extracted from these seeds suggested that the plants had exchanged their pollen among their close neighbors. There was also a problem in that the PCR amplification of some SRK alleles was difficult because of their sequence diversity in the naturalized populations, as occurs in cultivars. Our results suggest that the exchange of S alleles between cultivars and naturalized populations occurs and that S alleles in naturalized populations are highly diverse. The methodology established in our study should be applicable to other self-incompatible species to dissect the diversity of S allele distribution in naturalized populations.

Discovery of 1-[2-(1-methyl-1H-pyrazol-5-yl)-[1,2,4]triazolo[1,5-a]pyridin-6-yl]-3-(pyridin-4-ylmethyl)urea as a potent NAMPT (nicotinamide phosphoribosyltransferase) activator with attenuated CYP inhibition.

Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the rate-limiting step of the NAD+ salvage pathway. Since NAD+ plays a pivotal role in many biological processes including metabolism and aging, activation of NAMPT is an attractive therapeutic target for treatment of diverse array of diseases. Herein, we report the continued optimization of novel urea-containing derivatives which were identified as potent NAMPT activators. Early optimization of HTS hits afforded compound 12, with a triazolopyridine core, as a lead compound. CYP direct inhibition (DI) was identified as an issue of concern, and was resolved through modulation of lipophilicity to culminate in 1-[2-(1-methyl-1H-pyrazol-5-yl)-[1,2,4]triazolo[1,5-a]pyridin-6-yl]-3-(pyridin-4-ylmethyl)urea (21), which showed potent NAMPT activity accompanied with attenuated CYP DI towards multiple CYP isoforms.

Optimization of a urea-containing series of nicotinamide phosphoribosyltransferase (NAMPT) activators.

NAD+ is a crucial cellular factor that plays multifaceted roles in wide ranging biological processes. Low levels of NAD+ have been linked to numerous diseases including metabolic disorders, cardiovascular disease, neurodegeneration, and muscle wasting disorders. A novel strategy to boost NAD+ is to activate nicotinamide phosphoribosyltransferase (NAMPT), the putative rate-limiting step in the NAD+ salvage pathway. We previously showed that NAMPT activators increase NAD+ levels in vitro and in vivo. Herein we describe the optimization of our NAMPT activator prototype (SBI-0797812) leading to the identification of 1-(4-((4-chlorophenyl)sulfonyl)phenyl)-3-(oxazol-5-ylmethyl)urea (34) that showed far more potent NAMPT activation and improved oral bioavailability.

Impact of Workplace on the Risk of Severe COVID-19.

Indiscriminate regional lockdowns aim to prevent the coronavirus disease 2019 (COVID-19) infection by restricting the movement of people; however, this comes with psychological, social, and economic costs. Measures are needed that complement lockdowns and reduce adverse effects. Epidemiological studies, to date, have identified high-risk populations, but not workplaces appropriate for closure. This study was conducted to provide evidence-based measures that used exact and reliable follow-up data of the PCR-positive COVID-19 cases to complement lockdowns. The data are not subjected to selection or follow-up biases, since the Japanese government, by law, must register and follow all the PCR-positive cases until either recovery or death. Direct customer exposure may affect the quantity of viral inoculum received, which, in turn, may affect the risk of the severity of disease at infection. Therefore, the professions of the cases were grouped according to their frequency of direct customer exposure (FDCE) based on subjective observations, which resulted in five workplaces; hospital, school, food service, outdoor service, and indoor office being identified. Analyzing the follow-up data, we obtained precise estimates for the risk of severe disease, defined as intensive care unit (ICU) hospitalization or death, for the workplaces adjusted for age, sex, family status, and comorbidity. Major findings are as follows: hospital and school are the lowest risk, food and outdoor services are, despite higher FDCE, safer than indoor office. Unemployed and unclear are the highest risk, despite low FDCE. These results suggest the following workplace-specific measures complementing the lockdown: school should not be closed and indiscriminate closing of food and outdoor service industries should be avoided, since it would be more effective to reinforce their efforts to promote adherence to public health guidelines among students and customers. These actions would also reduce the adverse effects of the lockdown. This study is the first to address the causality between the workplaces and severe disease. We introduce FDCE and adherence to public health guidelines (APHGs) to associate the workplace characteristics with the risk of COVID-19 severity, which provided the basis for the measures complementing lockdowns.

Analysis of amino acid profiles of blood over time and biomarkers associated with non-alcoholic steatohepatitis in STAM mice.

The changes in free amino acid (AA) levels in blood during the progression from non-alcoholic steatohepatitis (NASH) to hepatocellular carcinoma (HCC) are unclear. We investigated serum AA levels, along with biochemical and histological events, in a mouse model of NASH. We induced NASH in male C57BL/6J mice with a streptozotocin injection and high-fat diet after 4 weeks of age (STAM group). We chronologically (6, 8, 10, 12, and 16 weeks, n=4-12 mice/group) evaluated the progression from steatohepatitis to HCC by biochemical and histological analyses. The serum AA levels were determined using an AA analyzer. Serum aspartate aminotransferase and alanine aminotransferase levels were higher in the STAM group than in the normal group (non-NASH-induced mice). Histological analysis revealed that STAM mice had fatty liver, NASH, and fibrosis at 6, 8, and 10 weeks, respectively. Moreover, the mice exhibited fibrosis and HCC at 16 weeks. The serum branched-chain AA levels were higher in the STAM group than in the normal group, especially at 8 and 10 weeks. The Fischer ratio decreased at 16 weeks in the STAM group, with increasing aromatic AA levels. These results suggested that this model sequentially depicts the development of fatty liver, NASH, cirrhosis, HCC, and AA metabolism disorders within a short experimental period. Additionally, serum amyloid A was suggested to be a useful inflammation biomarker associated with NASH. We believe that the STAM model will be useful for studying AA metabolism and/or pharmacological effects in NASH.

Koji glycosylceramide commonly contained in Japanese traditional fermented foods alters cholesterol metabolism in obese mice.

Koji, which is manufactured by proliferating non-pathogenic fungus Aspergillus oryzae on steamed rice, is the base for Japanese traditional fermented foods. We have revealed that koji and related Japanese fermented foods and drinks such as amazake, shio-koji, unfiltered sake and miso contain abundant glycosylceramide. Here, we report that feeding of koji glycosylceramide to obese mice alters the cholesterol metabolism . Liver cholesterol was significantly decreased in obese mice fed with koji glycosylceramide. We hypothesized that their liver cholesterol was decreased because it was converted to bile acids. Consistent with the hypothesis, many bile acids were increased in the cecum and feces of obese mice fed with koji glycosylceramide. Expressions of CYP7A1 and ABCG8 involved in the metabolism of cholesterol were significantly increased in the liver of mice fed with koji glycosylceramide. Therefore, it was considered that koji glycosylceramide affects the cholesterol metabolism in obese mice.

Statistical resolutions for large variabilities in hair mineral analysis.

Measuring biomaterials is usually subject to error. Measurement errors are classified into either random errors or biases. Random errors can be well controlled using appropriate statistical methods. But, biases due to unknown, unobserved, or temporary causes, may lead to biased conclusions. This study describes a verification method to examine whether measurement errors are random or not and to determine efficient statistical methods. A number of studies have dealt with associations between hair minerals and exposures such as health, dietary or environmental conditions. Most review papers, however, emphasize the necessity for validation of hair mineral measurements, since large variations can cause highly variable results. To address these issues, we answer the following questions: How can we ascertain the reliability of measurements?How can we assess and control the variability of measurements?How do we efficiently determine associations between hair minerals and exposures?How can we concisely present the reference values? Since hair minerals all have distinctive natures, it would be unproductive to examine each mineral individually to find significant and consistent answers that apply to all minerals. To surmount this difficulty, we used one simple model for all minerals to explore quantitative answers. Hair mineral measurements of six-year-old children were analyzed based on the statistical model. The analysis verified that most of the measurements were reliable, and their inter-individual variations followed two-parameter distributions. These results allow for sophisticated study designs and efficient statistical methods to examine the effects of various kinds of exposures on hair minerals.

Dynamic localization of a yeast development-specific PP1 complex during prospore membrane formation is dependent on multiple localization signals and complex formation.

During the developmental process of sporulation in Saccharomyces cerevisiae, membrane structures called prospore membranes are formed de novo, expand, extend, acquire a round shape, and finally become plasma membranes of the spores. GIP1 encodes a regulatory/targeting subunit of protein phosphatase type 1 that is required for sporulation. Gip1 recruits the catalytic subunit Glc7 to septin structures that form along the prospore membrane; however, the molecular basis of its localization and function is not fully understood. Here we show that Gip1 changes its localization dynamically and is required for prospore membrane extension. Gip1 first associates with the spindle pole body as the prospore membrane forms, moves onto the prospore membrane and then to the septins as the membrane extends, distributes around the prospore membrane after closure, and finally translocates into the nucleus in the maturing spore. Deletion and mutation analyses reveal distinct sequences in Gip1 that are required for different localizations and for association with Glc7. Binding to Glc7 is also required for proper localization. Strikingly, localization to the prospore membrane, but not association with septins, is important for Gip1 function. Further, our genetic analysis suggests that a Gip1-Glc7 phosphatase complex regulates prospore membrane extension in parallel to the previously reported Vps13, Spo71, Spo73 pathway.

The Contactless Vital Sensing System Precisely Reflects R-R Interval in Electrocardiograms of Healthy Subjects.

BACKGROUND: The aim of the present study was to investigate the validity of the contactless vital sensing system that we previously developed. METHODS: A total of 111 healthy Japanese subjects were recruited from the University of Occupational and Environmental Health and the Panasonic Corporation AVC Networks Company. All subjects underwent an evaluation using the contactless vital sensing system and electrocardiography (ECG). We compared the R-R interval obtained using the new contactless sensing system to that obtained using ECG. RESULTS: A very strong correlation was observed between the instruments. CONCLUSIONS: This result confirms the validity of the new contactless sensing system in evaluating healthy subjects.

The Dysferlin Domain-Only Protein, Spo73, Is Required for Prospore Membrane Extension in Saccharomyces cerevisiae.

Sporulation of Saccharomyces cerevisiae is a developmental process in which an ascus containing four haploid spores forms from a diploid cell. During this process, newly formed membrane structures called prospore membranes extend along the nuclear envelope and engulf and package daughter nuclei along with cytosol and organelles to form precursors of spores. Proteins involved in prospore membrane extension, Vps13 and Spo71, have recently been reported; however, the overall mechanism of membrane extension remains unclear. Here, we identified Spo73 as an additional factor involved in prospore membrane extension. Analysis of a spo73∆ mutant revealed that it shows defects similar to those of a spo71∆ mutant during prospore membrane formation. Spo73 localizes to the prospore membrane, and this localization is independent of Spo71 and Vps13. In contrast, a Spo73 protein carrying mutations in a surface basic patch mislocalizes to the cytoplasm and overexpression of Spo71 can partially rescue localization to the prospore membrane. Similar to spo71∆ mutants, spo73∆ mutants display genetic interactions with the mutations in the SMA2 and SPO1 genes involved in prospore membrane bending. Further, our bioinformatic analysis revealed that Spo73 is a dysferlin domain-only protein. Thus, these results suggest that a dysferlin domain-only protein, Spo73, functions with a dual pleckstrin homology domain protein, Spo71, in prospore membrane extension. Analysis of Spo73 will provide insights into the conserved function of dysferlin domains, which is related to dysferlinopathy. IMPORTANCE Prospore membrane formation consists of de novo double-membrane formation, which occurs during the developmental process of sporulation in Saccharomyces cerevisiae. Membranes are formed into their proper size and shape, and thus, prospore membrane formation has been studied as a general model of membrane formation. We identified SPO73, previously shown to be required for spore wall formation, as an additional gene involved in prospore membrane extension. Genetic and cell biological analyses suggested that Spo73 functions on the prospore membrane with other factors in prospore membrane extension, counteracting the bending force of the prospore membrane. Spo73 is the first dysferlin domain-only protein ever analyzed. The dysferlin domain is conserved from yeast to mammals and is found in dysferlin proteins, which are involved in dysferlinopathy, although the precise function of the domain is unknown. Continued analysis of Spo73 will contribute to our understanding of the function of dysferlin domains and dysferlinopathy.

Prognosis of metastatic renal cell carcinoma with first-line interferon-α therapy in the era of molecular-targeted therapy.

The RCC-SELECT study showed the correlation between single nucleotide polymorphisms (SNP) in STAT3 gene and survival in metastatic renal cell carcinoma (mRCC) patients with first-line interferon-α (IFN-α). In that study, even patients with STAT3 SNP linked to shorter overall survival (OS) exhibited remarkably improved prognosis. All 180 patients evaluated in the above study were further analyzed for correlation between OS and demographics/clinicopathological parameters. OS was estimated using the Kaplan-Meier method. Associations between OS and potential prognostic factors were assessed using the log-rank test and the Cox proportional hazards model. The median OS was 42.8 months. Univariate analysis showed that worse Eastern Cooperative Oncology Group-performance status (ECOG-PS), high T stage, regional lymph node metastasis, distant metastasis, higher grade, infiltrative growth pattern, the presence of microscopic vascular invasion (MVI), hypercalcemia, anemia, thrombocytopenia and elevated C-reactive protein were significantly associated with OS. Multivariate analysis revealed that ECOG-PS (hazard ratio [HR] = 3.665, P = 0.0004), hypercalcemia (HR = 6.428, P = 0.0005) and the presence of MVI (HR = 2.668, P = 0.0109) were jointly significant poor prognostic factors. This is the first study analysing prognostic factors of mRCC patients with first-line IFN-α using large cohort of the prospective study. The present study suggests that first-line IFN-α is still a useful therapy for mRCC even in the era of molecular targeted therapy.

Randomized Controlled Study of the Efficacy, Safety and Quality of Life with Low Dose bacillus Calmette-Guérin Instillation Therapy for Nonmuscle Invasive Bladder Cancer.

PURPOSE: The optimal dose of intravesical bacillus Calmette-Guérin for the treatment of nonmuscle invasive bladder cancer is controversial. We investigated if induction therapy with low dose bacillus Calmette-Guérin could achieve a complete response rate similar to that of standard dose bacillus Calmette-Guérin, with less toxicity and higher quality of life. MATERIALS AND METHODS: After transurethral resection, patients with unresectable multiple nonmuscle invasive bladder cancer and/or carcinoma in situ were randomized to receive standard (80 mg) or low dose (40 mg) bacillus Calmette-Guérin instillation induction therapy (weekly, 8 times). The primary end point was noninferiority of low dose bacillus Calmette-Guérin with a null hypothesis of a 15% decrease in complete response rate. Secondary end points were recurrence-free survival, progression-free survival, overall survival, patient compliance, adverse events and quality of life using the EORTC QLQ-C30. RESULTS: In an intent to treat analysis of 166 patients the complete response rates for low dose and standard dose bacillus Calmette-Guérin were 79% (95% CI 0.70-0.88) and 85% (95% CI 0.77-0.92), respectively. Dunnett-Gent analysis revealed that the null hypothesis of inferiority of low dose bacillus Calmette-Guérin in terms of complete response could not be rejected (p = 0.119). However, there were no significant differences between the groups in terms of recurrence, progression and overall survival. Low dose bacillus Calmette-Guérin was associated with significantly less fever (p = 0.001) and micturition pain (p = 0.047), and significantly higher quality of life scores for global quality of life, role functioning and functional impairment. CONCLUSIONS: The noninferiority of low dose bacillus Calmette-Guérin was not proven. However, low dose bacillus Calmette-Guérin was associated with lower toxicity and higher quality of life compared to standard dose bacillus Calmette-Guérin in patients with nonmuscle invasive bladder cancer.

Optimization of cell line development in the GS-CHO expression system using a high-throughput, single cell-based clone selection system.

Therapeutic antibodies are commonly produced by high-expressing, clonal and recombinant Chinese hamster ovary (CHO) cell lines. Currently, CHO cells dominate as a commercial production host because of their ease of use, established regulatory track record, and safety profile. CHO-K1SV is a suspension, protein-free-adapted CHO-K1-derived cell line employing the glutamine synthetase (GS) gene expression system (GS-CHO expression system). The selection of high-producing mammalian cell lines is a crucial step in process development for the production of therapeutic antibodies. In general, cloning by the limiting dilution method is used to isolate high-producing monoclonal CHO cells. However, the limiting dilution method is time consuming and has a low probability of monoclonality. To minimize the duration and increase the probability of obtaining high-producing clones with high monoclonality, an automated single cell-based clone selector, the ClonePix FL system, is available. In this study, we applied the high-throughput ClonePix FL system for cell line development using CHO-K1SV cells and investigated efficient conditions for single cell-based clone selection. CHO-K1SV cell growth at the pre-picking stage was improved by optimizing the formulation of semi-solid medium. The efficiency of picking and cell growth at the post-picking stage was improved by optimization of the plating time without decreasing the diversity of clones. The conditions for selection, including the medium formulation, were the most important factors for the single cell-based clone selection system to construct a high-producing CHO cell line.

Synthesis and biological evaluation of QRSTUVWXYZA' domains of maitotoxin.

The synthesis of QRSTUVWXYZA' domains 7, 8, and 9 of the highly potent marine neurotoxin maitotoxin (1), the largest secondary metabolite isolated to date, is described. The devised synthetic strategy entailed a cascade Takai-Utimoto ester olefination/ring closing metathesis to construct ring Y, a hydroxydithioketal cyclization/methylation sequence to cast ring X, a Horner-Wadsworth-Emmons coupling of WXYZA' ketophosphonate 11 with QRSTU aldehyde 12 to form enone 10, and a reductive hydroxyketone ring closure to forge ring V. 2D NMR spectroscopic analysis and comparison of (13)C chemical shifts with those of the corresponding carbons of maitotoxin revealed close similarities supporting the originally assigned structure of this region of the natural product. Biological evaluations of various synthesized domains of maitotoxin in this and previous studies from these laboratories led to fragment structure-activity relationships regarding their ability to inhibit maitotoxin-elicited Ca(2+) influx in rat C6 glioma cells.

Synthesis and SAR studies of benzyl ether derivatives as potent orally active S1P1 agonists.

We report herein the synthesis and structure-activity relationships (SAR) of a series of benzyl ether compounds as an S1P1 receptor modulator. From our SAR studies, the installation of substituents onto the central benzene ring of 2a was revealed to potently influence the S1P1 and S1P3 agonistic activities, in particular, an ethyl group on the 2-position afforded satisfactory S1P1/S1P3 selectivity. These changes of the S1P1 and S1P3 agonistic activities caused by the alteration of substituents on the 2-position were reasonably explained by a docking study using an S1P1 X-ray crystal structure and S1P3 homology modeling. We found that compounds 2b and 2e had a potent in vivo immunosuppressive efficacy along with acceptable S1P1/S1P3 selectivity, and confirmed that these compounds had less in vivo bradycardia risk through the evaluation of heart rate change after oral administration of the compounds (30 mg/kg, p.o.) in rats.

STAT3 polymorphism can predict the response to interferon-α therapy in patients with metastatic renal cell carcinoma.

BACKGROUND: In our 2007 retrospective study, we reported that single nucleotide polymorphisms (SNPs) in the signal transducer and activator of transcription 3 (acute-phase response factor) (STAT3) gene were significantly associated with better response to interferon (IFN)-α in patients with metastatic renal cell carcinoma (mRCC). OBJECTIVE: To prospectively confirm those results, the Japan Immunotherapy SNPs-Study Group for Kidney Cancer conducted this trial. DESIGN, SETTING, AND PARTICIPANTS: In this multicenter, prospective study, 203 eligible patients were enrolled. We evaluated the correlation between the antitumor effects of IFN-α and 11 SNPs (STAT3-2, STAT3-0, SOCS3-1, IL4R-34, PTGS1-3, PTGS1-4, PTGS1-5, PTGS2-12, IRF2-67, ICSBP-38, and TAP2-5) in eight genes in 180 patients who received IFN-α for >12 wk. INTERVENTIONS: Patients were treated with three doses per week of IFN-α 5 million IU. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We analyzed the association of response to IFN-α and overall survival (OS) with genetic polymorphisms using a chi-square test and a logistic regression model. RESULTS AND LIMITATIONS: The response rate of IFN-α was 13.8% (28 of 203 patients; 9 complete responses [CRs], 19 partial responses [PRs]). The CR rate of 4.4% was higher than we expected. Response to IFN-α was not associated with any of the 11 SNPs examined. However, when we assessed patients with CR, PR, and stable disease >24 wk as a group representing those with clinical response, a significant association was observed between STAT3-2 (rs1905341) and the clinical response of IFN-α (p=0.039). Namely, C/C genotype of STAT3-2 was significantly associated with the clinical response of IFN-α and OS. These results were generated in Japanese patients and should be studied in other ethnic groups. CONCLUSIONS: This is the first prospective study demonstrating that a STAT3 polymorphism can be a predictive marker for treatment with IFN-α for patients with mRCC.