Single-cell transcriptome sequencing reveals aberrantly activated inter-tumor cell signaling pathways in the development of clear cell renal cell carcinoma.

BACKGROUND: Aberrant intracellular or intercellular signaling pathways are important mechanisms that contribute to the development and progression of cancer. However, the intercellular communication associated with the development of ccRCC is currently unknown. The purpose of this study was to examine the aberrant tumor cell-to-cell communication signals during the development of ccRCC. METHODS: We conducted an analysis on the scRNA-seq data of 6 ccRCC and 6 normal kidney tissues. This analysis included sub clustering, CNV analysis, single-cell trajectory analysis, cell-cell communication analysis, and transcription factor analysis. Moreover, we performed validation tests on clinical samples using multiplex immunofluorescence. RESULTS: This study identified eleven aberrantly activated intercellular signaling pathways in tumor clusters from ccRCC samples. Among these, two of the majors signaling molecules, MIF and SPP1, were mainly secreted by a subpopulation of cancer stem cells. This subpopulation demonstrated high expression levels of the cancer stem cell markers POU5F1 and CD44 (POU5F1hiCD44hiE.T), with the transcription factor POU5F1 regulating the expression of SPP1. Further research demonstrated that SPP1 binds to integrin receptors on the surface of target cells and promotes ccRCC development and progression by activating potential signaling mechanisms such as ILK and JAK/STAT. CONCLUSION: Aberrantly activated tumor intercellular signaling pathways promote the development and progression of ccRCC. The cancer stem cell subpopulation (POU5F1hiCD44hiE.T) promotes malignant transformation and the development of a malignant phenotype by releasing aberrant signaling molecules and interacting with other tumor cells.

MiR-15b-5p Promotes Growth and Metastasis of Renal Clear Cell Carcinoma / MiR-15b-5p Promueve el Crecimiento y la Metástasis del Carcinoma Renal de Células Claras

SUMMARY: We investigated the expression and clinical significance of miR-15b-5p in clear cell renal cell carcinoma (RCC) through bioinformatics analysis and experimental verification. The differentially expressed miRNAs were screened in the GEO database. Venn diagram showed that there were 5 up-regulated miRNAs (has-miR-210, has-miR-142-3p, has-miR-142-5p, has-miR-15b-5p, and has-miR-193a-3p) and only 1 down-regulated miRNA (has-miR-532-3p) that were commonly expressed between GSE189331 and GSE16441 datasets. This was further confirmed in TCGA. Further analysis showed that the has-miR-193a-3p, has-miR-142-3p, has- miR-142-5p, and has-miR-15b-5p were closely related to tumor invasion, distant metastasis and survival probability. The expression of miR-15b-5p in ccRCC tissues was significantly higher than that in adjacent normal kidney tissues (P0.05). Following inhibition of miR-15b-5p expression, RCC cells had attenuated proliferation, increased apoptosis, and attenuated migration and invasion. has-miR-15b-5p-WEE1, has-miR-15b-5p-EIF4E, has-miR-15b-5p-PPP2R1B may be three potential regulatory pathways in ccRCC. miR-15b-5p is highly expressed in cancer tissues of ccRCC patients. It may promote proliferation, inhibit apoptosis and enhance cell migration and invasion of RCC cells. The has-miR-15b-5p-WEE1, has-miR-15b-5p-EIF4E, and has-miR-15b-5p-PPP2R1B may be three potential regulatory pathways in ccRCC.

Investigamos la expresión y la importancia clínica de miR-15b-5p en el carcinoma de células renales (CCR) de células claras mediante análisis bioinformático y verificación experimental. Los miARN expresados diferencialmente se examinaron en la base de datos GEO. El diagrama de Venn mostró que había 5 miARN regulados positivamente (has-miR-210, has-miR-142-3p, has-miR-142-5p, has-miR-15b-5p y has-miR-193a-3p). ) y solo 1 miARN regulado negativamente (has-miR-532-3p) que se expresaron comúnmente entre los conjuntos de datos GSE189331 y GSE16441. Esto fue confirmado aún más en TCGA. Un análisis más detallado mostró que has-miR-193a-3p, has-miR-142-3p, has- miR-142-5p y has-miR-15b-5p estaban estrechamente relacionados con la invasión tumoral, la metástasis a distancia y la probabilidad de supervivencia. La expresión de miR-15b-5p en tejidos ccRCC fue significativamente mayor que la de los tejidos renales normales adyacentes (P 0,05). Tras la inhibición de la expresión de miR-15b-5p, las células RCC tuvieron una proliferación atenuada, un aumento de la apoptosis y una migración e invasión atenuadas. has-miR-15b-5p-WEE1, has- miR-15b-5p-EIF4E, has-miR-15b-5p-PPP2R1B pueden ser tres posibles vías reguladoras en ccRCC. miR-15b-5p se expresa altamente en tejidos cancerosos de pacientes con ccRCC. Puede promover la proliferación, inhibir la apoptosis y mejorar la migración celular y la invasión de células RCC. has-miR-15b-5p-WEE1, has- miR-15b-5p-EIF4E y has-miR-15b-5p-PPP2R1B pueden ser tres posibles vías reguladoras en ccRCC.

Partial versus radical nephrectomy for the treatment of pT3aN0M0 renal cell carcinoma: A propensity score analysis.

BACKGROUND: The survival benefit of partial nephrectomy (PN) in pT3a RCC patients is controversial. Here we aimed to explore the potential benefit of PN for pT3aN0M0 renal cell carcinoma (RCC). MATERIAL AND METHODS: Data of patients with pT3aN0M0 RCC who were diagnosed between 2010 and 2012 in the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database were retrospectively collected. Overall survival (OS) and cancer specific survival (CSS) were compared using a Cox proportional hazards model between PN and radical nephrectomy (RN) in pT3aN0M0 RCC. Propensity score (-adjusted, -stratified, -weighted, and -matched) analyses were performed to control for imbalances in individual risk factors. RESULTS: A total of 1277 patients with pT3aN0M0 RCC were identified, of whom 200 patients were treated with PN and 1077 patients were RN. PN showed favorable OS and CSS in 0-4 cm pT3aN0M0 RCC (P < 0.05), and similar OS and CSS in 4-7 cm pT3aN0M0 RCC, compared with RN using un-adjusted analyses. The Propensity score analyses further demonstrated the survival benefit of PN compared with the RN in 0-4 cm pT3aN0M0 RCC (P < 0.05). CONCLUSIONS: In this retrospective study, PN was associated with improved survival compared with RN in 0-4 cm pT3aN0M0 RCC. Moreover, survival was comparable between PN and RN in 4-7 cm pT3aN0M0 RCC. These data provided evidence that PN could be an alternative choice for T3aN0M0 RCC less than 7 cm. Particularly, patients with 0-4 cm pT3aN0M0 RCC might benefit from PN.

Pien Tze Huang Inhibits Migration and Invasion of Hepatocellular Carcinoma Cells by Repressing PDGFRB/YAP/CCN2 Axis Activity.

OBJECTIVE: To investigate the effects of Pien Tze Huang (PZH) on the migration and invasion of HCC cells and underlying molecular mechanism. METHODS: Cell counting kit-8 (CCK-8) was applied to evaluate the cell viabilities of SMMC-7721, SK-Hep-1, C3A and HL-7702 (6 × 103 cells/well) co-incubated with different concentrations of PZH (0, 0.2, 0.4, 0.6, 0.8 mg/mL) for 24 h. Transwell, wound healing assay, CCK-8 and Annexin V-FITC/PI staining were conducted to investigate the effects of PZH on the migration, invasion, proliferation and apoptosis of SK-Hep-1 and SMMC-7721 cells (650 µ g/mL for SK-Hep-1 cells and 330 µ g/mL for SMMC-7721 cells), respectively. In vivo, lung metastasis mouse model constructed by tail vein injection of HCC cells was used for evaluating the anti-metastasis function of PZH. SK-Hep-1 cells (106 cells/200 µ L per mice) were injected into B-NDG mice via tail vein. Totally 8 mice were randomly divided into PZH and control groups, 4 mice in each group. After 2-d inoculation, mice in the PZH group were administered with PZH (250 mg/kg, daily) and mice in the control group received only vehicle (PBS) from the 2nd day after xenograft to day 17. Transcriptome analysis based on RNA-seq was subsequently used for deciphering anti-tumor mechanism of PZH. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were applied to verify RNA-seq results. Luciferase reporter assay was performed to examine the transcriptional activity of yes-associated protein (YAP). RESULTS: PZH treatment significantly inhibited the migration, invasion, proliferation and promoted the apoptosis of HCC cells in vitro and in vivo (P<0.01). Transcriptome analysis indicated that Hippo signaling pathway was associated with anti-metastasis function of PZH. Mechanical study showed PZH significantly inhibited the expressions of platelet derived growth factor receptor beta (PDGFRB), YAP, connective tissue growth factor (CCN2), N-cadherin, vimentin and matrix metallopeptidase 2 (MMP2, P<0.01). Meanwhile, the phosphorylation of YAP was also enhanced by PZH treatment in vitro and in vivo. Furthermore, PZH played roles in inhibiting the transcriptional activity of YAP. CONCLUSION: PZH restrained migration, invasion and epithelial-mesenchymal transition of HCC cells through repressing PDGFRB/YAP/CCN2 axis.

Sex differences in symptoms, high-resolution manometry values and efficacy of peroral endoscopic myotomy in Chinese patients with achalasia.

OBJECTIVE: We aimed to identify the differences in symptoms, high-resolution manometry (HRM) characteristics, and the efficacy of peroral endoscopic myotomy (POEM) regarding patients' sex in achalasia. METHODS: All patients diagnosed with achalasia by HRM who underwent POEM and were followed up for more than 6 months were included. The individual characteristics, symptoms and signs, POEM findings, HRM results and potentially related complications in male and female patients were reviewed. RESULTS: Prior to POEM, dysphagia was more severe in female than male patients (P = 0.044), while regurgitation was more severe (P = 0.013) and heartburn was more common in male patients (P = 0.003). Regarding HRM characteristics, the lower esophageal sphincter pressure (LESP) was higher (P = 0.01) and length of esophagus was shorter in female patients than in male patients. Eckardt scores, LESP and integrated relaxation pressure were significantly improved after the POEM procedure (P < 0.001). No significant difference was observed between the sexes regarding the efficacy of POEM, reflux symptoms, HRM data and complications after POEM. CONCLUSIONS: Before they seek treatment, female patients with achalasia may experience severe dysphagia and male patients are more likely to experience heartburn and more severe regurgitation. POEM is a safe and effective option for treating both male and female patients with achalasia.

Mechanism of adrenergic CaV1.2 stimulation revealed by proximity proteomics.

Increased cardiac contractility during the fight-or-flight response is caused by ß-adrenergic augmentation of CaV1.2 voltage-gated calcium channels1-4. However, this augmentation persists in transgenic murine hearts expressing mutant CaV1.2 α1C and ß subunits that can no longer be phosphorylated by protein kinase A-an essential downstream mediator of ß-adrenergic signalling-suggesting that non-channel factors are also required. Here we identify the mechanism by which ß-adrenergic agonists stimulate voltage-gated calcium channels. We express α1C or ß2B subunits conjugated to ascorbate peroxidase5 in mouse hearts, and use multiplexed quantitative proteomics6,7 to track hundreds of proteins in the proximity of CaV1.2. We observe that the calcium-channel inhibitor Rad8,9, a monomeric G protein, is enriched in the CaV1.2 microenvironment but is depleted during ß-adrenergic stimulation. Phosphorylation by protein kinase A of specific serine residues on Rad decreases its affinity for ß subunits and relieves constitutive inhibition of CaV1.2, observed as an increase in channel open probability. Expression of Rad or its homologue Rem in HEK293T cells also imparts stimulation of CaV1.3 and CaV2.2 by protein kinase A, revealing an evolutionarily conserved mechanism that confers adrenergic modulation upon voltage-gated calcium channels.

A combination of the modified Stoppa approach and the iliac fossa approach in treating compound acetabular fractures by using an anterior ilioischial plate.

Most compound acetabular fractures involving both the anterior and posterior columns are caused by high-energy injuries. Patients with compound acetabular fractures are often in critical or poor condition and cannot tolerate major surgery. This study aims to investigate the effectiveness of an ilioischial plate in treating compound acetabular fractures. A consecutive series of 40 patients with complex acetabular fractures were surgically treated and retrospectively reviewed. A modified Stoppa approach in combination with an iliac fossa approach was used. In all of the cases, the anterior column was stabilized with reconstruction plates for the iliac wing and along the iliopectineal line to the pubis. The posterior column was fixed either with the newly developed ilioischial plate running from the ilium to the ischial ramus or with standard fixation techniques. These included either conventional posterior column screws or quadrilateral plate fixation. Patients were divided into an experimental group (ilioischial plate for posterior column fixation) and a control group (standard fixation techniques). In both groups, we found that 90% of all reductions were good to excellent. According to the modified Merle Aubigne and Postel scoring system, the percentage of good to excellent was 85% in the experimental group as compared to 80% in the control group. Compared with the control group, physical function (PF), role physical (RP) and social function (SF) were significantly better in the experimental group (P<0.05). Fracture healing was achieved in all patients. By using the modified Stoppa approach combined with the iliac fossa approach, the ilioischial plate can be directly fixed to the posterior column and the ilium to stabilize the posterior column in patients with complex acetabular fractures.

[Correlation of 41 loci of single nucleotide polymorphisms with testicular germ cell tumor].

Objective: To identify genetic susceptibility genes and the loci of their single nucleotide polymorphisms (SNPs) in patients with testicular germ cell tumor (TGCT) and provide some new ideas for the prediction, diagnosis and treatment of TGCT. METHODS: We identified 41 SNP loci of TGCT-related genetic susceptibility genes from the literature published abroad. Using the iMLDRTM genotyping technique, we examined the SNP loci of the genetic susceptibility genes in the blood samples from 76 TGCT patients (aged 16－68 years) and 148 healthy men (aged 22－61 years) in China and analyzed their correlation with TGCT. RESULTS: In China, TGCT was found to be correlated with the SNP loci rs2978381, rs10146204, rs12435857 and rs1256063 of the ESR2 gene, rs9397080 of the ESR1 gene, rs11202586 of the PTEN gene, rs2606345 and rs4646903 of the CYP1A1 gene, and rs1456432 of the CYP19A1 gene. CONCLUSIONS: The results of our study indicated some difference in the positive SNP loci of the TGCT patients between Chinese and foreign cohorts as well as in different groups in China.

Proteolytic cleavage and PKA phosphorylation of α1C subunit are not required for adrenergic regulation of CaV1.2 in the heart.

Calcium influx through the voltage-dependent L-type calcium channel (CaV1.2) rapidly increases in the heart during "fight or flight" through activation of the ß-adrenergic and protein kinase A (PKA) signaling pathway. The precise molecular mechanisms of ß-adrenergic activation of cardiac CaV1.2, however, are incompletely known, but are presumed to require phosphorylation of residues in α1C and C-terminal proteolytic cleavage of the α1C subunit. We generated transgenic mice expressing an α1C with alanine substitutions of all conserved serine or threonine, which is predicted to be a potential PKA phosphorylation site by at least one prediction tool, while sparing the residues previously shown to be phosphorylated but shown individually not to be required for ß-adrenergic regulation of CaV1.2 current (17-mutant). A second line included these 17 putative sites plus the five previously identified phosphoregulatory sites (22-mutant), thus allowing us to query whether regulation requires their contribution in combination. We determined that acute ß-adrenergic regulation does not require any combination of potential PKA phosphorylation sites conserved in human, guinea pig, rabbit, rat, and mouse α1C subunits. We separately generated transgenic mice with inducible expression of proteolytic-resistant α1C Prevention of C-terminal cleavage did not alter ß-adrenergic stimulation of CaV1.2 in the heart. These studies definitively rule out a role for all conserved consensus PKA phosphorylation sites in α1C in ß-adrenergic stimulation of CaV1.2, and show that phosphoregulatory sites on α1C are not redundant and do not each fractionally contribute to the net stimulatory effect of ß-adrenergic stimulation. Further, proteolytic cleavage of α1C is not required for ß-adrenergic stimulation of CaV1.2.

Clinical comparison of patients with benign urachal masses versus urachal carcinomas.

The clinical features of 17 patients with benign urachal masses and 30 patients with urachal carcinoma treated at Sun Yat-sen University Cancer Center were analyzed retrospectively. Univariate analysis indicated that seven parameters differed significantly between the two groups. Binary logistic regression analyses showed that the rate of gross hematuria was significantly higher (P = 0.042, Exp[B] = 7.889) and the rate of fatty infiltration of the Retzius space was significantly lower (P = 0.006, Exp[B] = 0.028) in patients with urachal carcinoma than in those with benign urachal masses. Gross hematuria and fatty infiltration of the Retzius space may be indications of malignant and benign urachal masses, respectively.

Bilateral pelvic lymph node dissection for Chinese patients with penile cancer: a multicenter collaboration study.

BACKGROUND: Current guidelines recommend pelvic lymphadenectomy (PLND) for patients with pelvic lymph node metastasis and special state. However, these data and recommendations do not distinguish the role of PLND in different patient groups and confirm the final benefits. The aim of this study was to confirm the efficacy of pelvic lymphadenectomy (PLND) for the different groups of patients. METHODS: Data obtained from 7 centers were retrospectively analyzed. Of the patients, 190 pN2-3 penile carcinoma patients confirmed by bilateral inguinal lymph node excision were included in this study. Sixty-nine and 121 of these patients did and did not undergo bilateral PLND, respectively. The baseline differences from the patients were matched by propensity score analysis. RESULTS: In this study, the Kaplan-Meier estimated disease-specific survival (DSS) was not significantly different between the PLND and no-PLND groups (P = 0.796). According to the propensity score matching for T stage, N stage, grade, adjuvant therapies, and lymph node stage (number of inguinal lymph node metastasis and extranodal extension), 48 patients were selected for each group. Among the pN2 patients, the PLND group showed higher DSS rates than the no-surgery group (P = 0.030). However, even after matching, survival did not differ between the PLND and no-PLND patients among all patients (P = 0.609) and pN3 patients (P = 0.417) with comparable DSS. CONCLUSION: Bilateral PLND may improve survival in pN2 patients. Men with pN3 may not benefit from bilateral PLND.

Evaluation of Vitronectin Expression in Prostate Cancer and the Clinical Significance of the Association of Vitronectin Expression with Prostate Specific Antigen in Detecting Prostate Cancer.

PURPOSE: To detect the expression of vitronectin (VTN) in the tissues and blood serum of prostate cancer (PCa) patients, and evaluate its clinical significance and to evaluate the significance of the combined assay of VTN and prostate specific antigens (PSA) in PCa diagnosis. MATERIALS AND METHODS: To detect the expression of VTN as a potential marker for PCa diagnosis and prognosis, immunohistochemistry was performed on the tissues of 32 patients with metastatic PCa (PCaM), 34 patients with PCa without metastasis (PCa), and 41 patients with benign prostatic hyperplasia (BPH). The sera were then subjected to Western blot analysis. All cases were subsequently examined to determine the concentrations of PSA and VTN in the sera. The collected data were collated and analyzed. RESULTS: The positive expression rates of VTN in the tissues of the BPH and PCa groups (including PCa and PCaM groups) were 75.61% and 45.45%, respectively (P = .005). VTN was more highly expressed in the sera of the BPH patients (0.83 ± 0.07) than in the sera of the PCa patients (0.65 ± 0.06) (P < .05). It was also more highly expressed in the sera of the PCa patients than in the sera of the PCaM patients (0.35 ± 0.08) (P < .05). In the diagnosis of BPH and PCa, the Youden indexes of PSA detection, VTN detection, and combined detection were 0.2620, 0.3468, and 0.5635; the kappa values were 0.338, 0.304, and 0.448, respectively, and the areas under the receiver operating characteristic curve were 0.625, 0.673, and 0.703 (P < .05), respectively. CONCLUSION: VTN levels in sera may be used as a potential marker of PCa for the diagnosis and assessment of disease progression and metastasis. The combined detection of VTN and PSA in sera can be clinically applied in PCa diagnosis. .

Effect and clinical significance of fast-track surgery combined with laparoscopic radical gastrectomy on the plasma level of vascular endothelial growth factor in gastric antrum cancer.

This study discusses the effect and clinical significance of fast-track surgery (FTS) combined with laparoscopic radical surgery on the plasma level of vascular endothelial growth factor (VEGF) in locally advanced gastric antrum cancer. Plasma VEGF levels were detected in 63 cases of locally advanced gastric antrum cancer by using double-antibody sandwich Avidinbiotincomplex-ELISA before and after operation. The pure laparoscopic surgery group (group A) comprised 30 cases, and the combined FTS group (group B) consisted of 33 cases. Results of the two groups were obtained at similar time points and then compared. The VEGF levels were not significantly different between the two groups on the first day before the operation and on the first day, third day, and sixth month after the operation (P > 0.05). However, the differences were significant on the seventh day and first month after the operation (P < 0.05). The postoperative eating time, anal exhaust time, and hospital stay of the patients were statistically significantly different between the two groups (P < 0.05). Nevertheless, no significant differences were detected in terms of wound healing time and complications (P > 0.05). The 3-year survival rate significantly differed between the two groups (P < 0.05). FTS combined with laparoscopic surgery can decrease the postoperative VEGF level compared with pure laparoscopic surgery. The combined approach improved postoperative recovery without prolonging the wound healing time or increasing the incidence of postoperative complications. The 3-year survival rate also increased. Thus, FTS combined with laparoscopic surgery can improve the prognosis in gastric antrum cancer.

Application of AJCC/UICC and WHO-2010 classifications for GEP-NEN in Chinese patients.

OBJECTIVE: To assess the prognostic value in Chinese patients of two new systems, the World Health Organization (WHO)-2010 and the American Joint Committee on Cancer and the Union for International Cancer Control (AJCC/UICC) systems, for the classification of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN). METHODS: One hundred and three patients with GEP-NEN treated at the First Affiliated Hospital of Nanjing Medical University from January 2003 to December 2011 were included in the study. All patients were diagnosed pathologically and had complete follow-up data. Univariate and multivariate analyses of their clinicopathological characteristics were performed. RESULTS: The 5-year survival rates were 95%, 74%, 24% and 15% based on the AJCC/UICC stages I to IV, and 92%, 62% and 29% according to WHO-2010 grades 1 to 3, respectively, in patients with GEP-NEN. A higher mortality was observed in patients with AJCC/UICC stage III and IV tumors compared with those at stage I-II, and patients with stage II compared with those with stage I, whereas there was no difference in survival between stage IV and III patients. Based on the WHO-2010 grading classification, patients with grade 3 tumors had the lowest survival rate than those with grade 1 and 2 tumors, followed by patients with grade 2 tumors. CONCLUSION: The WHO-2010 and AJCC/UICC staging systems can effectively evaluate the prognosis of patients with GEP-NEN, although the latter might not accurately discriminate the prognosis of patients with local metastasis from those having distant metastasis.

Association between FSHR polymorphisms and polycystic ovary syndrome among Chinese women in north China.

PURPOSE: Polycystic ovary syndrome (PCOS) is a common endocrine disorder disease among women in reproductive-age. Since follicle stimulating hormone (FSH) exerts important biological functions, the association between PCOS and FSH receptor (FSHR) polymorphisms attracts wide attention. The aim of this study was to evaluate whether polymorphisms of FSHR at 307 and 680 codons are associated with PCOS patients in China. METHODS: Patients with PCOS (n = 215) and controls (n = 205) were recruited from Shanxi Province in north China. They are Han ethnics. Genomic DNA was isolated from the venous blood. The Ala307Thr and Ser680Asn polymorphisms of FSHR were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct DNA sequencing. RESULTS: The distributions of genotype and allele of Ala307Thr and Ser680Asn polymorphisms of FSHR were not statistically different between the PCOS patients and the controls. Analysis of the frequency of FSHR polymorphisms showed no statistical difference among the PCOS patients with different obesity standards. Although there were no statistical differences in the most of the endocrine parameters including LH, LH/FSH, E2, P and T as well as the clinical pregnancy rate, there were significant differences in the levels of FSH and PRL among PCOS patients carrying different genotypes of Ala307Thr and Ser680Asn polymorphisms. CONCLUSION: The Ala307Thr and Ser680Asn polymorphisms of FSHR are not associated with PCOS in Han ethnic Chinese women in north China. The FSHR polymorphisms was related to the levels of FSH and PRL but not other PCOS-associated endocrine hormones as well as clinical pregnancy rate in PCOS patients of Han Chinese ethnical population.

Orphan nuclear receptor TR3 acts in autophagic cell death via mitochondrial signaling pathway.

Autophagy is linked to cell death, yet the associated mechanisms are largely undercharacterized. We discovered that melanoma, which is generally resistant to drug-induced apoptosis, can undergo autophagic cell death with the participation of orphan nuclear receptor TR3. A sequence of molecular events leading to cellular demise is launched by a specific chemical compound, 1-(3,4,5-trihydroxyphenyl)nonan-1-one, newly acquired from screening a library of TR3-targeting compounds. The autophagic cascade comprises TR3 translocation to mitochondria through interaction with the mitochondrial outer membrane protein Nix, crossing into the mitochondrial inner membrane through Tom40 and Tom70 channel proteins, dissipation of mitochondrial membrane potential by the permeability transition pore complex ANT1-VDAC1 and induction of autophagy. This process leads to excessive mitochondria clearance and irreversible cell death. It implicates a new approach to melanoma therapy through activation of a mitochondrial signaling pathway that integrates a nuclear receptor with autophagy for cell death.

The orphan receptor TR3 participates in angiotensin II-induced cardiac hypertrophy by controlling mTOR signalling.

Angiotensin II (AngII) induces cardiac hypertrophy and increases the expression of TR3. To determine whether TR3 is involved in the regulation of the pathological cardiac hypertrophy induced by AngII, we established mouse and rat hypertrophy models using chronic AngII administration. Our results reveal that a deficiency of TR3 in mice or the knockdown of TR3 in the left ventricle of rats attenuated AngII-induced cardiac hypertrophy compared with the respective controls. A mechanistic analysis demonstrates that the TR3-mediated activation of mTORC1 is associated with AngII-induced cardiac hypertrophy. TR3 was shown to form a trimer with the TSC1/TSC2 complex that specifically promoted TSC2 degradation via a proteasome/ubiquitination pathway. As a result, mTORC1, but not mTORC2, was activated; this was accompanied by increased protein synthesis, enhanced production of reactive oxygen species and enlarged cell size, thereby resulting in cardiac hypertrophy. This study demonstrates that TR3 positively regulates cardiac hypertrophy by influencing the effect of AngII on the mTOR pathway. The elimination or reduction of TR3 may reduce cardiac hypertrophy; therefore, TR3 is a potential target for clinical therapy.

Calcium signaling through CaMKII regulates hepatic glucose production in fasting and obesity.

Hepatic glucose production (HGP) is crucial for glucose homeostasis, but the underlying mechanisms have not been fully elucidated. Here, we show that a calcium-sensing enzyme, CaMKII, is activated in a calcium- and IP3R-dependent manner by cAMP and glucagon in primary hepatocytes and by glucagon and fasting in vivo. Genetic deficiency or inhibition of CaMKII blocks nuclear translocation of FoxO1 by affecting its phosphorylation, impairs fasting- and glucagon/cAMP-induced glycogenolysis and gluconeogenesis, and lowers blood glucose levels, while constitutively active CaMKII has the opposite effects. Importantly, the suppressive effect of CaMKII deficiency on glucose metabolism is abrogated by transduction with constitutively nuclear FoxO1, indicating that the effect of CaMKII deficiency requires nuclear exclusion of FoxO1. This same pathway is also involved in excessive HGP in the setting of obesity. These results reveal a calcium-mediated signaling pathway involved in FoxO1 nuclear localization and hepatic glucose homeostasis.