Suppression of autophagy induces senescence in the heart.

Aging is a critical risk factor for heart disease, including ischemic heart disease and heart failure. Cellular senescence, characterized by DNA damage, resistance to apoptosis and the senescence-associated secretory phenotype (SASP), occurs in many cell types, including cardiomyocytes. Senescence precipitates the aging process in surrounding cells and the organ through paracrine mechanisms. Generalized autophagy, which degrades cytosolic materials in a non-selective manner, is decreased during aging in the heart. This decrease causes deterioration of cellular quality control mechanisms, facilitates aging and negatively affects lifespan in animals, including mice. Although suppression of generalized autophagy could promote senescence, it remains unclear whether the suppression of autophagy directly stimulates senescence in cardiomyocytes, which, in turn, promotes myocardial dysfunction in the heart. We addressed this question using mouse models with a loss of autophagy function. Suppression of general autophagy in cardiac-specific Atg7 knockout (Atg7cKO) mice caused accumulation of senescent cardiomyocytes. Induction of senescence via downregulation of Atg7 was also observed in chimeric Atg7 cardiac-specific KO mice and cultured cardiomyocytes in vitro, suggesting that the effect of autophagy suppression upon induction of senescence is cell autonomous. ABT-263, a senolytic agent, reduced the number of senescent myocytes and improved cardiac function in Atg7cKO mice. Suppression of autophagy and induction of senescence were also observed in doxorubicin-treated hearts, where reactivation of autophagy alleviated senescence in cardiomyocytes and cardiac dysfunction. These results suggest that suppression of general autophagy directly induces senescence in cardiomyocytes, which in turn promotes cardiac dysfunction.

Prognostic model for second progression-free survival and overall survival in patients with high-risk metastatic hormone-sensitive prostate cancer treated with abiraterone acetate and androgen deprivation therapy.

BACKGROUND: To develop and validate a prognostic risk model for high-risk metastatic hormone-sensitive prostate cancer (mHSPC) patients treated with upfront abiraterone acetate (ABI). METHODS: This retrospective multicenter study involved 233 high-risk mHSPC patients who received upfront ABI, developed by three academic centers. The model was externally validated with an independent cohort of 282 patients. To identify independent prognostic factors for second progression-free survival (PFS2) and develop the best-fitted model, Cox proportional hazards regression, followed by the Akaike information criterion, was used. Patients were categorized into three groups based on their risk scores. PFS2 and overall survival (OS) were evaluated according to the risk groups in the discovery and validation cohorts. RESULTS: The median age was 72 (range 51-89) years, with a median follow-up duration of 27 months. Independent factors linked to PFS2 included an Eastern Cooperative Oncology Group performance status ≥2, a primary Gleason score of 5, an extent of disease score of ≥3 or liver metastasis, and lactate dehydrogenase >220 U/L. Median PFS2 for favorable-, intermediate-, and poor-risk groups were not reached, 43 months, and 16 months, respectively. The median OS was 29 months in the poor-risk group, whereas it was not reached in the favorable- and intermediate-risk groups. The 2-year OS rates in the favorable-, intermediate- and poor-risk groups were 94.5%, 80.1%, and 60.3%, respectively. The validation cohort confirmed the risk model's relationship with PFS2 and OS. The median PFS2 and OS in the high-risk group were 21 months and 32 months, respectively. CONCLUSIONS: Our prognostic model, including five clinical factors, is useful for patient care and treatment selection in high-risk mHSPC patients treated with ADT plus ABI. The developed model could provide more accurate information, guide treatment decisions, or classify patients in future clinical trials.

Real clinical outcomes of nivolumab plus ipilimumab for renal cell carcinoma in patients over 75 years old.

BACKGROUND: Although nivolumab plus ipilimumab is the standard treatment for metastatic renal cell carcinoma (RCC), its efficacy and safety in older patients remain unclear. Therefore, this study aimed to assess the clinical outcomes of nivolumab plus ipilimumab for metastatic RCC in patients aged ≥ 75 years. METHODS: We enrolled 120 patients with metastatic RCC treated with nivolumab plus ipilimumab from August 2015 to January 2023. Objective response rates (ORRs) were compared between patients aged < 75 and ≥ 75 years. Progression-free survival (PFS), overall survival (OS), and adverse events were compared between the groups. Adverse events were evaluated according to the Response Evaluation Criteria in Solid Tumors 1.1. RESULTS: Among the patients, 57 and 63 were classified as intermediate and poor risk, respectively, and one could not be classified. The median follow-up duration after the initiation of treatment was 16 months. The patient characteristics between the groups, except for age, were not significantly different. Intergroup differences in ORR (42% vs. 40%; p = 0.818), PFS (HR: 0.820, 95% CI 0.455-1.479; p = 0.510), and median OS (HR: 1.492, 95% CI 0.737-3.020; p = 0.267) were not significant. The incidence of adverse events (50% vs. 67%; p = 0.111) and nivolumab plus ipilimumab discontinuation due to adverse events was not significantly different between the groups (14% vs. 13%; p = 0.877). CONCLUSIONS: The effectiveness of nivolumab plus ipilimumab was comparable between patients with metastatic RCC aged < 75 and those ≥ 75 years with respect to their ORRs, PFS, OS, and adverse event rates.

Real-world survival outcomes of adding docetaxel or abiraterone in patients with high-volume metastatic castration-sensitive prostate cancer: historically controlled, propensity score matched comparison with androgen deprivation therapy.

PURPOSE: This study investigated the impact of treatment intensification with upfront docetaxel (DOC) or abiraterone (ABI) plus prednisolone on survival outcomes in patients with metastatic castration-sensitive prostate cancer (mCSPC) by comparing it with androgen deprivation therapy (ADT) monotherapy or combined androgen blockade (CAB) using propensity score matching (PSM). METHODS: Outcomes from 278 CHAARTED high-volume patients receiving upfront DOC (92 patients) or upfront ABI (186 patients) were compared to those from 354 patients receiving ADT or CAB. PSM was conducted to assess castration-resistant prostate cancer-free survival (CRPCFS) and overall survival (OS). RESULTS: After PSM, patient distributions between the three groups were well balanced. After 1:1 PSM, patients receiving upfront ABI had significantly better CRPCFS than those receiving ADT/CAB or upfront DOC [hazard ratio (HR) 0.39; 95% CI 0.27-0.56 vs. HR 0.50; 95% CI 0.30-0.82, respectively]. No significant difference in CRPCFS was observed between the upfront DOC and ADT/CAB groups (HR 0.75; 95% CI 0.50-1.12). Patients receiving upfront DOC and upfront ABI had significantly better OS than those receiving ADT/CAB (HR 0.54; 95% CI 0.0.30-0.98 vs. HR 0.49; 95% CI 0.29-0.84, respectively). However, no significant difference in OS was observed between upfront ABI and upfront DOC (hazard ratio 0.84; 95% CI 0.34-2.06). CONCLUSION: The comparison of real-world retrospective cohorts showed that treatment intensification with upfront DOC or upfront ABI promoted better OS compared to ADT alone or CAB in patients with high-volume mCSPC after PSM. However, no difference in OS was observed between upfront DOC and upfront ABI.

Real-world outcomes and risk stratification in patients with metastatic castration-sensitive prostate cancer treated with upfront abiraterone acetate and docetaxel.

PURPOSE: We assessed clinical outcomes in patients with metastatic castration-sensitive prostate cancer (mCSPC) treated with two upfront therapies. METHODS: The medical records of 301 patients with mCSPC treated with androgen deprivation therapy plus upfront abiraterone acetate (ABI) or docetaxel (DOC) between 2014 and 2021 were retrospectively reviewed. Propensity score matching (PSM) was performed to compare survival outcomes. Subgroup analyses of risk factors for second progression were conducted. RESULTS: A total of 95 patients received upfront DOC, whereas 206 received upfront ABI. After PSM, the ABI group had a significantly better castration-resistant prostate cancer (CRPC)-free survival than the DOC group [hazard ratio (HR), 0.53; 95% confidence interval (CI), 0.34-0.82]. Second progression-free survival (PFS2) tended to be longer in the ABI group than in the DOC group, but the difference was not statistically significant (HR, 0.64; 95% CI, 0.33-1.22). No significant difference in overall survival (OS) was found between the two groups (HR, 0.92; 95% CI, 0.42-2.03). In the subgroup analysis, upfront ABI had significantly favorable PFS2 in patients aged ≥ 75 years compared with upfront DOC (p = 0.038). Four risk factors for second progression (primary Gleason 5, liver metastasis, high serum alkaline phosphatase level, and high serum lactate dehydrogenase level) successfully stratified patients into three risk groups. CONCLUSIONS: Upfront ABI provided better CRPC-free survival than upfront DOC; however, no significant differences in PFS2 or OS were observed between the two groups. Personalized management based on prognostic risk factors may benefit patients with mCSPC treated with upfront intensified therapies.

Incidence and location of positive surgical margin among open, laparoscopic and robot-assisted radical prostatectomy in prostate cancer patients: a single institutional analysis.

OBJECTIVE: To evaluate the positive surgical margin rates and locations in radical prostatectomy among three surgical approaches, including open radical prostatectomy, laparoscopic radical prostatectomy and robot-assisted radical prostatectomy. METHODS: We retrospectively reviewed clinical outcomes at our institution of 450 patients who received radical prostatectomy. Multiple surgeons were involved in the three approaches, and a single pathologist conducted the histopathological diagnoses. Positive surgical margin rates and locations among the three approaches were statistically assessed, and the risk factors of positive surgical margin were analyzed. RESULTS: This study included 127, 136 and 187 patients in the open radical prostatectomy, laparoscopic radical prostatectomy and robot-assisted radical prostatectomy groups, respectively. The positive surgical margin rates were 27.6% (open radical prostatectomy), 18.4% (laparoscopic radical prostatectomy) and 13.4% (robot-assisted radical prostatectomy). In propensity score-matched analyses, the positive surgical margin rate in the robot-assisted radical prostatectomy was significantly lower than that in the open radical prostatectomy, whereas there was no significant difference in the positive surgical margin rates between robot-assisted radical prostatectomy and laparoscopic radical prostatectomy. In the multivariable analysis, PSA level at diagnosis and surgical approach (open radical prostatectomy vs robot-assisted radical prostatectomy) were independent risk factors for positive surgical margin. The apex was the most common location of positive surgical margin in the open radical prostatectomy and laparoscopic radical prostatectomy groups, whereas the bladder neck was the most common location in the robot-assisted radical prostatectomy group. The significant difference of positive surgical margin locations continued after the propensity score adjustment. CONCLUSIONS: Robot-assisted radical prostatectomy may potentially achieve the lowest positive surgical margin rate among three surgical approaches. The bladder neck was the most common location of positive surgical margin in robot-assisted radical prostatectomy and apex in open radical prostatectomy and laparoscopic radical prostatectomy. Although robot-assisted radical prostatectomy may contribute to the reduction of positive surgical margin, dissection of the bladder neck requires careful attention to avoid positive surgical margins.

[Tuberous Sclerosis Complex Detected by Spontaneous Rupture of a Giant Renal Angiomyolipoma : A Case Report].

A woman in her 30s was admitted with abdominal pain and nausea. CT scan revealed a spontaneous rupture of the right giant renal angiomyolipoma, and trans-arterial embolization was performed successfully. With further examination, she was found to be affected with tuberous sclerosis complex (TSC) and she finally wastreated with everolimusfor prevention of recurrent spontaneous-rupture of renal angiomyolipoma.

[Pazopanib for three patients with recurrence of retroperitoneal liposarcoma : initial clinical experience].

Pazopanib, a novel tyrosine kinase inhibitor, is an effective therapeutic agent for patients with advanced soft tissue sarcoma. Here we report three patients with recurrent retroperitoneal liposarcoma who were treated with pazopanib. Case 1: A 54-year-old male received three courses of combined chemotherapy consisting of doxorubicin and ifosfamide for recurrent left retroperitoneal dedifferentiated liposarcoma and liver metastasis following tumor excision. Because of the lack of response to chemotherapy, 400 mg/day of pazopanib was subsequently administered for two weeks. The patient died 3 weeks after the initiation of pazopznib therapy. Case 2: A 78-year-old male with right retroperitoneal dedifferentiated liposarcoma underwent irradiation for a recurrent tumor 16 months after the initial tumor excision. Pazopanib (600 mg/day) was partially effective for 2 months. Pazopanib was administered for 7 months, but the patient died 8 months after the initiation of pazopanib therapy. Case 3 : An 80-year-old male with locally recurrent right retroperitoneal myxoid liposacroma was treated with 600 mg/day of pazopanib from 5 months after tumor excision. He remains alive and has had stable disease for 17 months to date. In conclusion, pazopanib may be effective in a subset of patients with recurrent retroperitoneal liposarcoma.

Suppression of autophagy induces senescence in the heart.

Aging is a critical risk factor for heart disease, including ischemic heart disease and heart failure. Cellular senescence, characterized by DNA damage, resistance to apoptosis and the senescence-associated secretory phenotype (SASP), occurs in many cell types, including cardiomyocytes. Senescence precipitates the aging process in surrounding cells and the organ through paracrine mechanisms. Generalized autophagy, which degrades cytosolic materials in a non-selective manner, is decreased during aging in the heart. This decrease causes deterioration of cellular quality control mechanisms, facilitates aging and negatively affects lifespan in animals, including mice. Although suppression of generalized autophagy could promote senescence, it remains unclear whether the suppression of autophagy directly stimulates senescence in cardiomyocytes, which, in turn, promotes myocardial dysfunction in the heart. We addressed this question using mouse models with a loss of autophagy function. Suppression of general autophagy in cardiac-specific Atg7 knockout ( Atg7 cKO) mice caused accumulation of senescent cardiomyocytes. Induction of senescence via downregulation of Atg7 was also observed in chimeric Atg7 cardiac-specific KO mice and cultured cardiomyocytes in vitro , suggesting that the effect of autophagy suppression upon induction of senescence is cell autonomous. ABT-263, a senolytic agent, reduced the number of senescent myocytes and improved cardiac function in Atg7 cKO mice. Suppression of autophagy and induction of senescence were also observed in doxorubicin-treated hearts, where activation of autophagy alleviated senescence in cardiomyocytes and cardiac dysfunction. These results suggest that suppression of general autophagy directly induces senescence in cardiomyocytes, which in turn promotes cardiac dysfunction.

Mst1-mediated phosphorylation of FoxO1 and C/EBP-ß stimulates cell-protective mechanisms in cardiomyocytes.

The molecular mechanisms by which FoxO transcription factors mediate diametrically opposite cellular responses, namely death and survival, remain unknown. Here we show that Mst1 phosphorylates FoxO1 Ser209/Ser215/Ser218/Thr228/Ser232/Ser243, thereby inhibiting FoxO1-mediated transcription of proapoptotic genes. On the other hand, Mst1 increases FoxO1-C/EBP-ß interaction and activates C/EBP-ß by phosphorylating it at Thr299, thereby promoting transcription of prosurvival genes. Myocardial ischemia/reperfusion injury is larger in cardiac-specific FoxO1 knockout mice than in control mice. However, the concurrent presence of a C/EBP-ß T299E phospho-mimetic mutation reduces infarct size in cardiac-specific FoxO1 knockout mice. The C/EBP-ß phospho-mimetic mutant exhibits greater binding to the promoter of prosurvival genes than wild type C/EBP-ß. In conclusion, phosphorylation of FoxO1 by Mst1 inhibits binding of FoxO1 to pro-apoptotic gene promoters but enhances its binding to C/EBP-ß, phosphorylation of C/EBP-ß, and transcription of prosurvival genes, which stimulate protective mechanisms in the heart.

Thioredoxin 1 promotes autophagy through transnitrosylation of Atg7 during myocardial ischemia.

Modification of cysteine residues by oxidative and nitrosative stress affects structure and function of proteins, thereby contributing to the pathogenesis of cardiovascular disease. Although the major function of thioredoxin 1 (Trx1) is to reduce disulfide bonds, it can also act as either a denitrosylase or transnitrosylase in a context-dependent manner. Here we show that Trx1 transnitrosylates Atg7, an E1-like enzyme, thereby stimulating autophagy. During ischemia, Trx1 was oxidized at Cys32-Cys35 of the oxidoreductase catalytic center and S-nitrosylated at Cys73. Unexpectedly, Atg7 Cys545-Cys548 reduced the disulfide bond in Trx1 at Cys32-Cys35 through thiol-disulfide exchange and this then allowed NO to be released from Cys73 in Trx1 and transferred to Atg7 at Cys402. Experiments conducted with Atg7 C402S-knockin mice showed that S-nitrosylation of Atg7 at Cys402 promotes autophagy by stimulating E1-like activity, thereby protecting the heart against ischemia. These results suggest that the thiol-disulfide exchange and the NO transfer are functionally coupled, allowing oxidized Trx1 to mediate a salutary effect during myocardial ischemia through transnitrosylation of Atg7 and stimulation of autophagy.

Complete remission of brain metastases in renal cell carcinoma treated with axitinib after failure with nivolumab and ipilimumab treatment.

Introduction: Complete remission of cerebral metastasis is a rare consequence of tyrosine kinase inhibitor monotherapy in patients with metastatic renal cell carcinoma. Case presentation: A 68-year-old woman, who presented with dyspnea, was diagnosed with left renal cell carcinoma with multiple brain and pleural metastases. Although nivolumab and ipilimumab combination treatment was initiated, it was discontinued because of an immune-related adverse event. Two months after treatment cessation, brain metastases progressed regardless of shrinkage of primary renal tumor and pleural metastases. Therefore, axitinib was started as a second-line treatment, which resulted in the complete disappearance of the brain metastases along with the stable disease of the other tumor lesions. Conclusion: This is the first report of complete remission of brain metastases in renal cell carcinoma treated by axitinib.

Impact of cascade screening for catecholaminergic polymorphic ventricular tachycardia type 1.

OBJECTIVE: Human cardiac ryanodine receptor 2 (RYR2) shows autosomal-dominant inheritance in catecholaminergic polymorphic ventricular tachycardia type 1 (CPVT1); however, de novo variants have been observed in sporadic cases. Here, we investigated CPVT1-related RYR2 variant inheritance and its clinical significance between familial and de novo cases. METHODS: We enrolled 82 independent CPVT1 probands (median age: 10.0 (7.0-13.0) years; 45 male) carrying the RYR2 variants and whose biological origin could be confirmed by parental genetic analysis: assured familial inheritance (familial group: n=24) and de novo variants (de novo group: n=58). We examined the clinical characteristics of the probands and their family members carrying the RYR2 variants. RESULTS: In the de novo group, the RYR2 variants were more likely located in the C-terminus domain and less likely in the N-terminus domain than those in the familial group. The cumulative incidence of the first cardiac events (syncope and cardiac arrest (CA) or CA only) of the probands at the age of 5 and 10 years was higher in the de novo group than in the familial group. Nearly half of the probands in both groups experienced CA events before diagnosis. Only 37.5% of their genotype-positive parents had symptoms; however, at least 66.7% of the genotype-positive siblings were symptomatic. CONCLUSIONS: CPVT1 probands harbouring de novo RYR2 variants showed an earlier onset of symptoms than those with assured familial inheritance. Cascade screening may enable early diagnosis, risk stratification and prophylactic therapeutic intervention to prevent sudden cardiac death of probands and potential genotype-positive family members.

[Primary retroperitoneal carcinoid tumor associated with multiple endcrine neoplasia (men) type 1: a case report].

We report an extremely rare case of a 69-year-old man having a retroperitoneal carcinoid tumor associated with multiple endocrine neoplasia (MEN) type 1. The patient whose son and daughter were previously diagnosed with MEN type 1 was admitted to the Department of Endocrinology at our hospital for evaluation of this disorder. Computed tomography (CT) and ultrasonography revealed a parathyroid and retroperitoneal tumor (43 mm x 34 mm). The patient did not consent to surgical management of the tumor; however three years later, a follow-up CT revealed tumor enlargement (55 mm x 50 mm). We were unable to rule out a malignancy, and subsequently resected the tumor. A pathological diagnosis of retroperitoneal carcinoid was made. No local recurrence or metastasis have been observed for 21 months.

Cancer Antigen 15-3 Serum Level as a Biomarker for Advanced Micropapillary Urothelial Carcinoma of the Bladder: A Case Report.

A 73-year-old woman with no history of disease was referred to our hospital with fatigue and joint pain. Screening blood test showed that her cancer antigen 15-3 (CA 15-3) serum level was elevated to 36.6 U/mL, and a contrast-enhanced computed tomography scan revealed a bladder tumor without metastasis. Cystoscopy showed a papillary and a small kissing tumor, and the histopathological analysis of the bladder tumor obtained by transurethral resection (TUR) showed invasive urothelial carcinoma (UC) with micropapillary variant (pT1). At 4 weeks after TUR, the CA 15-3 serum level was markedly increased to 180.6 U/mL, and radiographic examinations revealed multiple regional and nonregional lymph node metastases. The patient received systemic therapy with gemcitabine and cisplatin. After 3 cycles of chemotherapy, the size of all lymph node metastases reduced by 80% in diameter, and the CA 15-3 serum level decreased from 238.2 to 11.4 U/mL. Immunohistological analysis showed that the bladder tumor was positive for mucin 1, of which CA 15-3 is an epitope. In our patient, changes in the CA 15-3 serum levels were in congruence with the clinical course of advanced micropapillary UC (MPUC). Therefore, the CA 15-3 serum level may be a potentially valuable biomarker for MPUC.

Does the Addition of Abiraterone to Castration Affect the Reduction in Bone Mineral Density?

BACKGROUND/AIM: The in vivo effect of abiraterone on bone mineral density (BMD) in addition to androgen deprivation therapy was examined using a murine model. MATERIALS AND METHODS: The mice were separated into the following groups: control, abiraterone, castration, and castration+abiraterone. The percentage change in the ratio of bone to tissue volume (BV/TV), number of osteoblasts and osteoclasts, and the serum level of bone markers were compared on day 21. RESULTS: The BV/TV ratio of the abiraterone, castration, and castration+abiraterone groups was lower than that of the control group. However, the change in the BV/TV ratio in the castration+abiraterone group was not significantly different from that in the castration group. There was no significant difference in the serum TRAP5b level and the number of osteoclasts and osteoblasts between the castration+abiraterone and the castration groups. CONCLUSION: The addition of abiraterone to castration did not affect BMD in the murine model.

A de novo gain-of-function KCND3 mutation in early repolarization syndrome.

BACKGROUND: Early repolarization syndrome (ERS) is characterized by J-point elevation on electrocardiograms and ventricular fibrillation (VF). Early repolarization arises from augmentation of the transmural electrical gradient in the cardiac action potential; therefore, the transient outward potassium current (Ito) has been regarded as a key candidate current for elucidating the mechanism of ERS. KCND3 encoding Kv4.3, an α-subunit of the Ito channel, is considered as one of target genes. OBJECTIVE: The purpose of this study was to search for novel KCND3 mutations associated with ERS and to clarify the pathogenesis. METHODS: We performed genetic screening for 11 unrelated probands with ERS and analyzed the electrophysiological properties of detected mutations by patch-clamp methods. RESULTS: A novel de novo KCND3 heterozygous mutation, Gly306Ala (c.917g>c), was found in 1 proband. The proband was a 12-year-old boy, who suffered VF storm and showed significant J-point elevation in multiple leads. Intravenous isoproterenol and subsequent administration of quinidine were effective in preventing VF recurrence and restored the J-point elevation. In electrophysiological analysis, cultured cells expressing mutant Kv4.3 showed significantly increased current densities, slow inactivation, and slow recovery from inactivation compared to wild type. Extracellular application of quinidine significantly restored the inactivation time course in mutant Kv4.3. A simulation study confirmed the relationship between the novel KCND3 mutation and early repolarization on electrocardiograms. CONCLUSION: A novel KCND3 heterozygous mutation was found to be associated with ERS. The pathogenesis can be explained by the increased Ito. Genetic screening for KCND3 could be useful for understanding the pathogenesis and selecting effective treatment.

Novel intracellular transport-refractory mutations in KCNH2 identified in patients with symptomatic long QT syndrome.

BACKGROUND: Missense mutations in KCNH2, a gene encoding the Kv11.1 channel, cause long QT syndrome (LQTS) type 2 primarily by disrupting the intracellular transport of Kv11.1 to the plasma membrane. The present study aimed to clarify the functional changes by two novel KCNH2 missense mutations. METHODS: We performed genetic screening of three unrelated symptomatic LQTS probands with family histories of cardiac symptoms. Chinese hamster ovary cells were transfected with wild-type (WT) and/or mutant KCNH2 plasmid and examined by patch-clamp technique. Immunostaining and confocal microscopy were performed to evaluate the intracellular localization of WT and homozygous mutant Kv11.1 in human embryonic kidney cells. For the study of trafficking rescue, we used low-temperature incubation (30°C). We also examined pharmacological rescue of homozygous mutant Kv11.1 current in cells treated with E-4031 or dofetilide. RESULTS: We identified two novel KCNH2 missense mutations, G785D and T826I. Electrophysiological study showed that both mutant channels were nonfunctional in homozygous condition and reduced current densities by half in heterozygous condition compared with WT Kv11.1. Heterozygous Kv11.1-G785D produced a significant positive shift in activation and a significant negative shift in inactivation, whereas heterozygous Kv11.1-T826I caused no kinetic changes. Immunostaining revealed that both were transport-refractory mutations. Incubation at 30°C rescued plasma membrane expression of Kv11.1-T826I but not G785D. We confirmed low-temperature-induced restoration of homozygous Kv11.1-T826I transport by functional current measurements. In contrast, incubation with E-4031 or dofetilide failed to produce measurable currents in both homozygous mutant channels. CONCLUSIONS: Two novel KCNH2 mutations disrupted the intracellular transport of Kv11.1. Low-temperature incubation rescued plasma membrane expression of Kv11.1-T826I but not G785D. Both mutations exerted loss-of-function effects on Kv11.1 and explained the phenotypes of the mutation carriers.

The impact of obesity and adiponectin signaling in patients with renal cell carcinoma: A potential mechanism for the "obesity paradox".

Although obesity increases the risk of renal cell carcinoma (RCC), obese patients with RCC experience longer survival than non-obese patients. However, the mechanism of this "obesity paradox" is unknown. We examined the impact of preoperative BMI, serum total adiponectin (sAd) level, total adiponectin secretion from perinephric adipose tissue, and intratumoral expression of adiponectin receptors on RCC aggressiveness and survival. We also investigated the mechanism underlying enhanced cancer aggressiveness in RCC cells stimulated with exogenous adiponectin. Overweight and obese patients had significantly lower grade cancers than normal patients in all patients and in those without metastasis (p = 0.003 and p = 0.027, respectively). Cancer-specific survival was significantly longer in overweight and obese patients than in normal patients in all patients (p = 0.035). There was a weak inverse correlation between sAd level and BMI in RCC patients (r = -0.344, p = 0.002). Tumor size was slightly correlated with sAd level, and high sAd was significantly associated with poor overall survival rates in patients with non-metastatic RCC (p = 0.035). Adiponectin levels in perinephric adipose tissue and intratumoral AdipoR1/R2 expression were not correlated with RCC aggressiveness or survival. Proliferation significantly increased in 786-O and Caki-2 cells exposed to exogenous adiponectin, whereas cell invasion and migration were unaffected. In addition, exogenous adiponectin significantly inhibited starvation- and metformin-induced apoptosis, and up-regulated p-AMPK and Bcl-xL levels. In summary, low BMI and high adiponectin levels are associated with aggressive cell behaviors and poor survival in surgically-treated RCC patients. The effects of adiponectin on proliferation and apoptosis might underlie the "obesity paradox" of RCC.

Inhibition of the RANK/RANKL signaling with osteoprotegerin prevents castration-induced acceleration of bone metastasis in castration-insensitive prostate cancer.

Androgen deprivation therapy (ADT) for patients with metastatic or locally advanced prostate cancer reduces bone mineral density by stimulating receptor activator of nuclear factor kappa-B (RANK) signaling in osteoclasts. The involvement of the RANK/RANKL signaling in ADT-induced acceleration of bone metastasis in castration-insensitive prostate cancer was examined in a murine model using osteoprotegerin (OPG). Male Balb/c nude mice were divided into three groups: the non-castration, castration, and castration + OPG groups. PC-3M-luc-C6 was injected into the left ventricle of the mice. Recombinant OPG was injected intravenously twice weekly in the castration + OPG group. In-vivo imaging system (IVIS®) determined that the prevalence and photon counts of bone metastasis in the castration group were significantly higher than that in the non-castration and castration + OPG groups. The mean number of RANKL-positive osteoblasts and the mean serum RANKL level in the castration group were significantly higher than those in the non-castration group. RANKL-enhanced activation of osteoclasts was attenuated in the castration + OPG group. These results suggest that the mechanisms of RANK/RANKL signaling are involved in the ADT-induced acceleration of bone metastasis in castration-insensitive prostate cancer.