Intracellular Major Histocompatibility Complex Class II and C-X-C Motif Chemokine Ligand 10-Expressing Neutrophils Indicate the State of Anti-Tumor Activity Induced by Bacillus Calmette-Guérin.

(1) Background: Inflammatory responses induce the formation of both anti-tumor and pro-tumor neutrophils known as myeloid-derived suppressor cells (MDSCs). Intermittent intravesical infusion of Bacillus Calmette-Guérin (BCG) is an established cancer immunotherapy for non-muscle-invasive bladder cancer (NMIBC). However, the types of neutrophils induced via the inflammatory response to both tumor-bearing and BCG remain unclear. (2) Methods: We therefore analyzed neutrophil dynamics in the peripheral blood and urine of patients with NMIBC who received BCG therapy. Further, we analyzed the effects of BCG in a mouse intraperitoneal tumor model. (3) Results: BCG therapy induced the formation of CXCL10 and MHC class II-positive neutrophils in the urine of patients with NMIBC but did not induce MDSC formation. CXCL10- and MHC class II-expressing neutrophils were detected in peritoneal exudate cells formed after BCG administration. Partial neutrophil depletion using an anti-Ly6G antibody suppressed the upregulation of CXCL10 and MHC class II in neutrophils and reversed the anti-tumor activity of BCG in mouse models. (4) Conclusions: These results indicated that intracellular MHC class II- and CXCL10-expressing neutrophils indicate the state of anti-tumor activity induced via BCG. The status of neutrophils in mixed inflammation of immunosuppressive and anti-tumor responses may therefore be useful for evaluating immunological systemic conditions.

Initial Myeloid Cell Status Is Associated with Clinical Outcomes of Renal Cell Carcinoma.

The therapeutic outcome of immune checkpoint inhibition (ICI) can be improved through combination treatments with ICI therapy. Myeloid-derived suppressor cells (MDSCs) strongly suppress tumor immunity. MDSCs are a heterogeneous cell population, originating from the unusual differentiation of neutrophils/monocytes induced by environmental factors such as inflammation. The myeloid cell population consists of an indistinguishable mixture of various types of MDSCs and activated neutrophils/monocytes. In this study, we investigated whether the clinical outcomes of ICI therapy could be predicted by estimating the status of the myeloid cells, including MDSCs. Several MDSC indexes, such as glycosylphosphatidylinositol-anchored 80 kD protein (GPI-80), CD16, and latency-associated peptide-1 (LAP-1; transforming growth factor-ß1 precursor), were analyzed via flow cytometry using peripheral blood derived from patients with advanced renal cell carcinoma (n = 51) immediately before and during the therapy. Elevated CD16 and LAP-1 expressions after the first treatment were associated with a poor response to ICI therapy. Immediately before ICI therapy, GPI-80 expression in neutrophils was significantly higher in patients with a complete response than in those with disease progression. This is the first study to demonstrate a relationship between the status of the myeloid cells during the initial phase of ICI therapy and clinical outcomes.

Anti-human leukocyte antigen and anti-ABO antibodies after SARS-CoV-2 mRNA vaccination in kidney transplant recipients.

INTRODUCTION: In this study, we evaluated whether SARS-CoV-2 mRNA vaccines induce anti-human leukocyte antigen (HLA) antibodies and anti- ABO blood type antibodies (ABOAb) in kidney transplant recipients (KTRs). METHODS: Sixty-three adult KTRs with functioning grafts who received two doses of the SARS-CoV-2 mRNA vaccine were enrolled in this cohort. Changes in anti-ABO blood type immunoglobulin IgM and IgG antibody titers, flow panel reactive antibody (PRA), de novo donor-specific anti-human leukocyte antigen antibodies (DSA), and kidney allograft function before and after vaccination were evaluated. RESULTS: Only one patient experienced conversion from negative to positive flow PRA after vaccination. However, there was no DSA in single antigen flow-bead assays. The mean fluorescence intensity (MFI) in the eight DSA-positive recipients did not significantly change before and after vaccination (p = .383), and no additional DSA was produced after vaccination in those patients. No significant elevation of ABOAb titer was observed for either IgM (p = .438) or IgG (p = .526) after vaccination. There was no significant deterioration in estimated glomerular filtration rate (eGFR) after vaccination (p = .877) or elevation of the urine protein-to-creatinine ratio (p = .209) after vaccination. One episode of AMR was observed in addition to a preexisting acute cellular rejection. CONCLUSIONS: The SARS-CoV-2 mRNA vaccine did not induce anti-HLA antibody or ABOAb production in KTRs.

Fibroblast growth factor receptor type 4 as a potential therapeutic target in clear cell renal cell carcinoma.

BACKGROUND: Several clear cell renal cell carcinoma (ccRCC) cases harbour fibroblast growth factor receptor 4 (FGFR4) gene copy number (CN) gains. In this study, we investigated the functional contribution of FGFR4 CN amplification in ccRCC. METHODS: The correlation between FGFR4 CN determined via real-time PCR and protein expression evaluated using western blotting and immunohistochemistry was assessed in ccRCC cell lines (A498, A704, and 769-P), a papillary RCC cell line (ACHN), and clinical ccRCC specimens. The effect of FGFR4 inhibition on ccRCC cell proliferation and survival was assessed via either RNA interference or using the selective FGFR4 inhibitor BLU9931, followed by MTS assays, western blotting, and flow cytometry. To investigate whether FGFR4 is a potential therapeutic target, a xenograft mouse model was administered BLU9931. RESULTS: 60% of ccRCC surgical specimens harboured an FGFR4 CN amplification. FGFR4 CN was positively correlated with its protein expression. All ccRCC cell lines harboured FGFR4 CN amplifications, whereas ACHN did not. FGFR4 silencing or inhibition attenuated intracellular signal transduction pathways, resulting in apoptosis and suppressed proliferation in ccRCC cell lines. BLU9931 suppressed tumours at a tolerable dose in the mouse model. CONCLUSION: FGFR4 contributes to ccRCC cell proliferation and survival following FGFR4 amplification, making it a potential therapeutic target for ccRCC.

Humoral and cellular immune response and the safety of third SARS-CoV-2 mRNA vaccine with longer interval after the second vaccination in kidney transplant recipients.

We evaluated the humoral and cellular immune responses and safety of the third severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine with a longer interval after the second vaccination in kidney transplant recipients (KTRs). We enrolled 54 kidney transplant recipients without a history of coronavirus disease 2019 (COVID-19), who received a third dose of the vaccine. We assessed anti-SARS-CoV-2 spike antibody and antigen-specific T cells using enzyme-linked immunospot (ELISpot) against the spike protein at baseline, after the second vaccination, and after the third vaccination. We also evaluated the adverse events related to each dose of the vaccine. The duration between the second and third vaccinations was 7 ± 1 month. All 17 (100%) KTRs with anti-SARS-CoV-2 antibody positivity after the second vaccination and 27 of 37 (73%) KTRs without anti-SARS-CoV-2 antibody positivity after the second vaccination were positive for anti-SARS-CoV-2 antibodies (p=0.022). Anti-SARS-CoV-2 antibody titers were significantly higher than those after the second vaccination (p<0.001). Age ≥ 60 years and lymphocyte count < 1150/mm3 were confirmed as risk factors for anti-SARS-CoV-2 antibody negativity after the third vaccination in multivariate regression analysis. ELISpot cytokine activities were positive after the third vaccination in 26 of 29 (90%) KTRs with ELISpot cytokine activity positivity after the second vaccination and 12 of 24 (50%) KTRs without ELISpot cytokine activity after the second vaccination. The rate of change in cytokine activity after the third vaccination was significantly higher than that after the second vaccination (p<0.001). Only lymphocyte counts less than 1150/mm3 were confirmed as risk factors for ELISpot cytokine activity negativity in the multivariate regression analysis. Systemic adverse events classified as greater than moderate did not differ for each vaccine dose. None of the patients showed clinical symptoms of acute rejection. The third SARS-CoV-2 mRNA vaccine administration, with a longer interval after the second vaccination, improved humoral and cellular immune responses to SARS-CoV-2 mRNA vaccines without severe adverse effects in the KTRs.

Effect of Extracellular Signal-Regulated Protein Kinase 5 Inhibition in Clear Cell Renal Cell Carcinoma.

(1) Background: Extracellular signal-regulating kinase 5 (ERK5) has been implicated in many cellular functions, including survival, proliferation, and vascularization. Our objectives were to examine the expression and effect of ERK5 in clear cell renal cell carcinoma (ccRCC). (2) Methods: The expressions of ERK5 and its regulating micro-RNA miR-143 were investigated using immunohistochemistry and quantitative reverse transcriptase PCR in surgical specimens of ccRCC patients. With invitro and in vivo studies, we used pharmacologic ERK5 inhibitor XMD8-92, RNA interference, pre-miR-143 transduction, Western blotting, MTS assay, apoptosis assay, and subcutaneous xenograft model. (3) Results: A strong ERK5 expression in surgical specimen was associated with high-grade (p = 0.01), high-recurrence free rate (p = 0.02), and high cancer-specific survival (p = 0.03). Expression levels of ERK5 and miR-143 expression level were correlated (p = 0.049). Pre-miR-143 transduction into ccRCC cell A498 suppressed ERK5 expression. ERK5 inhibition enhanced cyclin-dependent kinase inhibitor p21 expression and decreased anti-apoptotic molecules BCL2, resulting in decreased cell proliferation and survival both in ccRCC and endothelial cells. In the xenograft model, ERK5 inhibitor XMD8-92 suppressed tumor growth. (4) Conclusions: ERK5 is regulated by miR-143, and ERK5 inhibition is a promising target for ccRCC treatment.

Immunogenicity and safety of two doses of SARS-CoV-2 mRNA vaccine in kidney transplant recipients with low-dose rituximab.

OBJECTIVES: We evaluated whether the treatment history of low-dose rituximab affected safety profiles, and humoral and cellular responses induced by severe acute respiratory syndrome coronavirus 2 messenger ribonucleic acid vaccine in healthy controls and kidney transplant recipients. METHODS: We enrolled 10 healthcare workers as controls, 22 kidney transplant recipients with rituximab, and 36 kidney transplant recipients without rituximab without history of coronavirus disease 2019 who received two doses of vaccine. We assessed anti-severe acute respiratory syndrome coronavirus 2 spike antibody and the antigen-specific T cells using enzyme-linked immunospot against spike protein at baseline and after two doses of vaccine. RESULTS: All controls showed anti-severe acute respiratory syndrome coronavirus 2 antibody seroconversion and enzyme-linked immunospot positivity. Only 19/58 (33%) kidney transplant recipients experienced anti-severe acute respiratory syndrome coronavirus 2 antibody seroconversion and 31/58 (53%) kidney transplant recipients developed enzyme-linked immunospot assay positivity after vaccination. The anti-severe acute respiratory syndrome coronavirus 2 antibody seroconversion rate and enzyme-linked immunospot assay positivity rate after vaccination were not significantly different between kidney transplant recipients with or without rituximab. Multivariate regression analysis demonstrated rituximab was not associated with a lack of humoral and cellular responses to the vaccine. CONCLUSIONS: Low-dose rituximab in kidney transplant recipients did not affect humoral or cellular responses to the severe acute respiratory syndrome coronavirus 2 messenger ribonucleic acid vaccine without severe systemic adverse events including the deterioration of kidney function.

Outcomes of Living Kidney Transplantation for Mitochondrial Disease Patients: A Case Series.

PURPOSE: Mitochondrial disease can affect many organs, including the brain, nerves, heart, liver, eyes, ears, pancreas, and kidneys. Kidney transplantation is a treatment option for renal failure due to mitochondrial disease; however, the prognosis of patients who undergo kidney transplantation for mitochondrial disease is unknown. Here we evaluated the outcomes of kidney transplant recipients with mitochondrial disease. METHODS: Clinical data were obtained from 4 kidney transplantation recipients who were followed at our department. Of the 4 transplantations, 3 were performed in our department: 2 patients received kidneys from their fathers, and a third from his wife. The fourth recipient received a kidney from her mother-who had a mitochondrial genetic abnormality-at another hospital. Of the 4 recipients, 3 were diagnosed with mitochondrial disease before the transplantation, and the fourth was diagnosed after. All recipients had sensorineural deafness and diabetes mellitus, and only 1 had a history of encephalopathy and stroke-like episodes before the transplantation. RESULTS: One patient died 2 years after transplantation due to encephalopathy progression with stable kidney function. The grafted kidney of the patient who received it from her mother lost function at 5 years post-transplantation. A graft biopsy revealed focal segmental glomerular sclerosis due to mitochondrial disease. The other patients' kidney functions remained stable. None of the recipients experienced rejection. CONCLUSIONS: In kidney transplantation for mitochondrial disease, attention should be paid to the exacerbation of comorbidities, while careful consideration should be given to donors with a mitochondrial genetic abnormality.

Clinical utility of head computed tomography scan during systemic therapy for metastatic renal cell carcinoma.

OBJECTIVES: The utility of brain metastasis screening in asymptomatic metastatic renal cell carcinoma is controversial. Our study evaluated the utility of routine head computed tomography during systemic therapy. METHODS: We retrospectively investigated 152 metastatic renal cell carcinoma patients who did not initially have brain metastasis at Yamagata University Hospital from January 2008 to July 2019. Patients who routinely received head computed tomography scan together with routine contrast-enhanced chest/abdominal/pelvic computed tomography scan every 2-4 months during systemic therapy ("Routine head computed tomography" group, n = 95) and patients without routine head computed tomography ("No routine head computed tomography" group, n = 57) were compared. RESULTS: Brain metastasis occurred in 16 patients in the "Routine head computed tomography" group and six patients in the "No routine head computed tomography" group. There was no statistical difference in overall survival after metastatic renal cell carcinoma diagnosis between groups (53.4 vs 37.3 months, respectively, P = 0.357) and neurological symptom-free survival after metastatic renal cell carcinoma diagnosis (53.4 vs 36.6 months, P = 0.336). Although there was no statistical difference on incidence of unrecovered neurological symptom (25.0% vs 50.0%, P = 0.334), fewer patients in the "Routine head computed tomography" group required craniotomy (0% vs 66.7%, P = 0.002). In the "No routine head computed tomography" group, the neurological symptom resolved for all patients without craniotomy. CONCLUSIONS: Routine head computed tomography during systemic therapy for metastatic renal cell carcinoma is not significantly associated with improved brain metastasis prognosis. However, routine head computed tomography enables brain metastasis diagnosis in the asymptomatic phase, which can avoid craniotomy.

New prognostic model for synchronous metastatic renal cell carcinoma.

OBJECTIVES: To create a new model for the prediction of overall survival in synchronous metastatic renal cell carcinoma. METHODS: Medical records of 158 patients with metastatic renal cell carcinoma diagnosed at the Yamagata University Hospital from August 2007 to February 2018 were reviewed. Among them, 77 with synchronous metastatic renal cell carcinoma were retrospectively analyzed using the univariate and multivariate analyses. A new prognostic model was constructed, followed by a bootstrap validation to estimate the model fitting. In addition, these prognostic factors were estimated in 67 metachronous metastatic renal cell carcinoma patients. RESULTS: Five independent prognostic factors were identified in synchronous metastatic renal cell carcinoma: cT3/4, cN1, high corrected calcium, >3.6 neutrophil-to-lymphocyte ratio and central nerve system metastasis. The number (%) and overall survival (95% confidence interval) in the favorable- (0 or 1 risk factor), intermediate- (2 risk factors) and poor-risk (≥3 risk factors) groups were 29 (45.3%) and 67.4 (31.8-NA), 21 (32.8%) and 16.8 (10.0-27.6), and 14 (21.9%) and 9.1 (7.3-13.7) months, respectively. The C-index was 0.72. Patients in the favorable-risk group had better overall survival with nephrectomy than without nephrectomy (hazard ratio 0.29, 95% confidence interval 0.09-0.91 with nephrectomy). In metachronous metastatic renal cell carcinoma, these prognostic factors showed no statistical differences in the overall survival. CONCLUSIONS: Prognostic factors are completely different between synchronous and metachronous metastatic renal cell carcinoma. The new model for synchronous metastatic renal cell carcinoma can predict a good candidate for cytoreductive nephrectomy.

Effect of third- and fourth-line systemic therapies for metastatic renal cell carcinoma.

Data on the outcomes of third- or fourth-line therapy for metastatic renal cell carcinoma (mRCC) are limited. The aim of our study was to evaluate the efficacy of therapy beyond the second line. We retrospectively analysed data of mRCC patients who underwent systemic therapy at Yamagata University Hospital. The best objective response (BOR), response rate (RR), and progression-free survival (PFS) were assessed for each line of treatment. To investigate the correlation between overall survival (OS) and the number of treatment lines during a patient's lifetime, the median OS was assessed using univariate and multivariate analyses. In the first-, second-, and third-line therapies, approximately 20% of patients had long PFS of >15 months. In targeted treatments beyond the third line, only one treatment suppressed disease progression for >10 months. Among patients who died during the follow-up period, those treated with triple and quadruple lines had similar OS (42.5 months vs. 48.4 months, respectively). Multivariate analysis showed that patients with triple or more lines of therapy had better OS; however, quadruple or more lines of therapy was not an independent prognostic factor. We concluded that third-line systemic therapy could improve OS; however, fourth-line therapy could not.

Risk of SOFA Deterioration in Conservative Treatment for Emphysematous Pyelonephritis: Pitfalls of Current Trends in Therapeutics from Multicenter Clinical Experience.

INTRODUCTION: We investigated relationships between therapeutic outcomes of patients with emphysematous pyelonephritis (EPN) and changes in the Sequential Organ Failure Assessment (SOFA) score. MATERIALS AND METHODS: We retrospectively evaluated EPN patients treated in our hospitals using the SOFA score incorporated in the Sepsis-3 updated in 2016. RESULTS: Seventeen typical EPN patients were included in this study, and were treated with medical management with no drainage (n = 3), retrograde stenting (n = 10), or percutaneous drainage (n = 3). One patient without drainage died of sepsis, yielding an overall mortality rate of 5.9%. Twelve patients recovered without increase in the SOFA score during hospitalization. However, the SOFA score deteriorated in the other patients from admission, with the initial scores not significantly different from those of the 12 cases. The changes in the SOFA score were significantly affected by the selected approaches of drainage (100% patients for no drainage, 22% for stenting, and 0% for percutaneous drainage, p = 0.029), but not by other clinical data. CONCLUSION: Most EPN patients can currently be conservatively managed successfully. However, it should be noted that less-invasive management could cause deterioration in SOFA after admission, yielding a risk of septic mortality.

Impact of eIF4E phosphorylation at Ser209 via MNK2a on tumour recurrence after curative surgery in localized clear cell renal cell carcinoma.

Background: We investigated the roles of eIF4E phosphorylation (Ser209) in tumour recurrence after curative nephrectomy for localized clear cell renal cell carcinoma (ccRCC). Methods: Expression of eIF4E, p eIF4E and MNKs (MAPK interacting kinases), was evaluated in surgical specimens obtained from consecutive non metastatic ccRCC patients (n = 290) by immunohistochemistry (IHC), immunoblotting, and qRT PCR at the protein and mRNA levels. In human RCC cell lines, the effects of eIF4E phosphorylation were examined using immunoblotting, proliferation, migration and invasion assays with pharmacological inhibitors (CGP57380 or ETP45835) and specific small interfering (si) RNAs against MNK1/2(a/b). Results: In postoperative follow-up (median, 7.9 y), 40 patients experienced metastatic recurrence. In multivariate Cox analyses, higher IHC expression of p eIF4E in ccRCC significantly predicted a longer recurrence-free interval. eIF4E is phosphorylated mainly by MNK2a in tumour specimens and cell lines. In 786-O and A-498 cell lines, pharmacological inhibition of MNKs decreased p-eIF4E and increased vimentin and N cadherin but did not influence proliferation. Similarly, MNK2 or MNK2a inhibition with siRNA reduced p-eIF4E and enhanced vimentin translation, cell migration and invasion in the cell lines. Conclusions: MNK2a-induced eIF4E phosphorylation may suppress metastatic recurrence of ccRCC, partially due to vimentin downregulation at the translational level, consequently leading to inhibition of epithelial-mesenchymal transition.

Expression of total and phospho 4EBP1 in metastatic and non-metastatic renal cell carcinoma.

Eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1) is phosphorylated and activated by mammalian target of rapamycin complex 1, which serves as a regulator of cell growth, cell survival, metastasis and angiogenesis in many types of cancer. The aim of this study was to evaluate the role of phosphorylated 4EBP1 (p4EBP1) in primary renal cell carcinoma (RCC) as a biomarker in metastatic RCC (mRCC) and non-mRCC cohorts. Primary tumor tissue from 254 non-mRCC and 60 mRCC patients were immunohistochemically stained for t4EBP1 and p4EBP1. The disease-free interval (DFI) categorized by the expressions and clinical parameters were assessed by univariate and multivariate analysis in the non-mRCC cohort. Then, the cause-specific survival (CSS) was assessed in the mRCC cohort by the same methods as used in the non-mRCC cohort. In the non-mRCC cohort, patients with t4EBP1 expression had no RCC recurrence. Patients with p4EBP1 expression had the shorter DFI in univariate analysis (P=0.037). p4EBP1 and pT1b-4 expression levels were independent predictors for de novo metastasis. In the mRCC cohort, intermediate/poor MSKCC risk, non-clear cell RCC, and no p4EBP1 expression were correlated with poor CSS on multivariate analysis. Expression of p4EBP1 could be a predictive biomarker for de novo metastasis in non-mRCC patient cohort. By contrast, mRCC patients showing no p4EBP1 expression had shorter CSS than patients with p4EBP1 expression.

Levels of 4EBP1/eIF4E Activation in Renal Cell Carcinoma Could Differentially Predict Its Early and Late Recurrence.

BACKGROUND: The objective was to explore the predictive markers of late recurrence (LR) > 5 years after curative nephrectomy for renal cell carcinoma (RCC). PATIENTS AND METHODS: We retrospectively examined the data from 303 patients with localized clear cell RCC treated surgically at our institution from 1993 to 2011. Activation of the eukaryotic initiation factor (eIF)4E-binding protein 1 (4EBP1)/eIF4E axis at the mammalian target of rapamycin complex 1 (mTORC1) was evaluated in the tumor specimens. Weak, intermediate, and strong immunohistochemistry staining grades were defined for 4EBP1, phosphorylated 4EBP1, and eIF4E. The effects of clinicopathologic factors and activation level grades on tumor recurrence were analyzed using multivariate Cox regression models. To validate the present findings, we investigated clinical data from The Cancer Genome Atlas and protein/phosphoprotein data from corresponding patients from The Cancer Proteome Atlas. RESULTS: Of the 303 patients, 31 and 16 patients developed early recurrence (ER, ≤ 5 years) and LR, respectively. The activation levels were comparable among the subcategories of pathologic TN stage, Fuhrman grade, and microvascular and capsular invasion. Pathologic stage ≥ T1b, Fuhrman grade 3/4, and an intermediate or strong activation level correlated significantly with overall recurrence and ER. Strong activation of the axis and pathologic stage ≥ T1b were identified as independent predictors of LR. Only 2 patients with weak activation experienced recurrence (1 each with ER and LR). Similar results were confirmed by the analyses of The Cancer Genome Atlas and The Cancer Proteome Atlas data. CONCLUSION: The activation level of the axis in RCC tissues could independently predict for recurrence and differentially affect the timing of recurrence.

Proteomics identified nuclear N-myc downstream-regulated gene 1 as a prognostic tissue biomarker candidate in renal cell carcinoma.

The aim of this study was to identify proteins with aberrant expression in clear cell renal cell carcinoma (ccRCC), and elucidate their clinical utilities. The protein expression profiles of primary ccRCC tumor tissues and neighboring non-tumor tissues were obtained from 9 patients by two-dimensional difference gel electrophoresis and mass spectrometry. Comparative analysis of 3771 protein spots led to the identification of 73 proteins that were expressed at aberrant levels in tumor tissues compared with non-tumor tissues. Among these 73 proteins, we further focused on N-myc downstream-regulated gene 1 protein (NDRG1). NDRG1 expression is regulated by members of myc family as well as by p53, HIF1A, and SGK1. The biological and clinical significance of NDRG1 is controversial for various malignancies and no detailed studies on NDRG1 have been reported in ccRCC until our study. For the 82 newly enrolled ccRCC patients, immunohistochemical analysis revealed a significant association between nuclear NDRG1 and favorable prognosis (p<0.05). Multivariate analysis demonstrated the role of NDRG1 as an independent factor of progression-free survival (p=0.01). Subsequent in vitro gene suppression assay demonstrated that NDRG1 silencing significantly enhanced cell proliferation and invasion of RCC cells. The cytotoxic effects of NDRG1 up-regulation induced by an iron chelator were also confirmed. These findings suggest that nuclear NDRG1 has tumor suppressive effects, and the NDRG1 expression may have clinical values in ccRCC. Nuclear NDRG1 may provide additional insights on molecular backgrounds of ccRCC progression, and contribute to the development of novel therapeutic strategy.