The inhibition of TRIM35-mediated TIGAR ubiquitination enhances mitochondrial fusion and alleviates renal ischemia-reperfusion injury.

Tripartite motif 35 (TRIM35) is a member of the tripartite motif protein family and has been recognized to play a key role in immune-inflammatory diseases. However, the role of TRIM35 in renal ischemia-reperfusion injury (IRI) remains unclear. Our study proved that knockdown of TRIM35 alleviates kidney IRI by inhibiting oxidative stress and enhancing mitochondrial fusion. In addition, our experimental results found that TRIM35 interacts with TP53-induced glycolysis and apoptosis regulator (TIGAR) and promotes the polyubiquitination of TIGAR and induces its degradation in the proteasome pathway. Furthermore, TIGAR knockdown significantly inhibited mitochondrial fusion. These results indicate that TRIM35 is a potential therapeutic target for renal IRI.

[Corrigendum] SMC1A promotes growth and migration of prostate cancer in vitro and in vivo.

Subsequently to the publication of the above article, an interested reader drew to the authors' attention that, on p. 1969, two pairs of panels shown for the DU145 data appeared to contain overlaps, such that they may have been derived from the same original source (specifically, relating to the shCon and the shSMC1A experiments). The authors have referred back to their original data, and realize that inadvertent errors were made during the assembly of these figures. The corrected version of Fig. 5, showing discrete representative images for the shCon and the shSMC1A experiments with the DU145 cell line, is shown on the next page. All the authors agree to this corrigendum. Note that the revisions made to this figure do not adversely affect the results reported in the paper, or the conclusions stated therein. The authors regret that Fig. 5 was not presented in its correct form in their paper, thank the Editor of International Journal of Oncology for granting them the opportunity to publish this corrigendum, and offer their apologies to the Editor and to the readers of the Journal. [the original article was published in International Journal of Oncology 49: 1963-1972, 2016; DOI: 10.3892/ijo.2016.3697].

MiR-25 regulates cell proliferation and metastasis in bladder urothelial carcinoma.

Background: Bladder urothelial carcinoma (BC) is a common malignant tumor with a high incidence. This study aims to explore the role of miR-25 in BC tumorigenesis. Material and Methods: The expression of miR-25 and PTEN were detected in clinical BC tissues. BC cell lines T24 and 5637 were used to transfect miR-25 mimics or inhibitors. Luciferase reporter gene detection confirmed the correlation between miR-25 and PTEN. CCK-8 method and flow cytometry were used to detect cell viability and apoptosis. Cell migration and invasion ability were examined by transwell assays. Western blotting detects the protein levels of PTEN, ß-catenin, GSK-3ß and p-GSK-3ß. Results: MiR-25 and PTEN expression are found to be negatively correlated in BC tissues. Further research confirmed that PTEN is a direct target of miR-25. In addition, the overexpression of miR-25 down-regulates the expression of PTEN, induces cell survival and inhibits apoptosis, while the knockout of miR-25 leads to the opposite result. miR-25 also inhibits the phosphorylation of GSK-3ß and ß-catenin without changing the total level of GSK-3ß. In vivo experiments confirmed that miR-25 plays an oncogene's role by regulating the PTEN and Wnt/ß-catenin signaling pathways. Conclusion: Our research shows that miR-25 has a negative regulatory effect on the expression of PTEN in clinical specimens and in vitro. miR-25 can promote the proliferation of BC cells and induce cell invasion. Therefore, miR-25 may be used as a biomarker to predict the progression of BC.

TRIM47 promotes malignant progression of renal cell carcinoma by degrading P53 through ubiquitination.

BACKGROUND: Renal cell carcinoma (RCC) is one of the most common malignant tumors originating from the renal parenchymal urinary epithelial system. Tripartite motif 47 (TRIM47) is a member of the TRIM family proteins, which has E3 ligase activity and has been demonstrated to be involved in the occurrence and prognosis of many tumors. The main purpose of this study is to explore the role and potential mechanism of TRIM47 in promoting malignant biological behavior of RCC. MATERIALS AND METHODS: TRIM47 mRNA and protein levels in human renal cancer and paired normal adjacent tissues were detected by qRT-PCR and Western blot. The effects of TRIM47 knockdown and overexpression in renal cell carcinoma cells on cell proliferation, invasion and xenograft tumor growth in nude mice were analyzed. The molecular mechanism was explored by mass spectrometric exploration,Western blot and immunoprecipitation assays. RESULTS: TRIM47 promoted RCC cell proliferation in vitro and in vivo as an oncogene. Mechanistically, TRIM47 exerted an E3 ligase activity by interacting with P53 protein to increase its ubiquitination and degradation, which further promoted the malignant biological behavior of RCC. CONCLUSIONS: Our study demonstrated that the TRIM47-P53 axis played a functional role in RCC progression and suggested a potential therapeutic target for RCC.

Identification of a novel cancer stem cell subpopulation that promotes progression of human fatal renal cell carcinoma by single-cell RNA-seq analysis.

Background: Cancer stem cells (CSCs) are biologically characterized by self-renewal, multi-directional differentiation and infinite proliferation, inducing anti-tumor drug resistance and metastasis. In the present study, we attempted to depict the baseline landscape of CSC-mediated biological properties, knowing that it is vital for tumor evolution, anti-tumor drug selection and drug resistance against fatal malignancy. Methods: We performed single-cell RNA sequencing (scRNA-seq) analysis in 15208 cells from a pair of primary and metastatic sites of collecting duct renal cell carcinoma (CDRCC). Cell subpopulations were identified and characterized by t-SNE, RNA velocity, monocle and other computational methods. Statistical analysis of all single-cell sequencing data was performed in R and Python. Results: A CSC population of 1068 cells was identified and characterized, showing excellent differentiation and self-renewal properties. These CSCs positioned as a center of the differentiation process and transformed into CDRCC primary and metastatic cells in spatial and temporal order, and played a pivotal role in promoting the bone destruction process with a positive feedback loop in the bone metastasis microenvironment. In addition, CSC-specific marker genes BIRC5, PTTG1, CENPF and CDKN3 were observed to be correlated with poor prognosis of CDRCC. Finally, we pinpointed that PARP, PIGF, HDAC2, and FGFR inhibitors for effectively targeting CSCs may be the potential therapeutic strategies for CDRCC. Conclusion: The results of the present study may shed new light on the identification of CSCs, and help further understand the mechanism underlying drug resistance, differentiation and metastasis in human CDRCC.

Gankyrin is a novel biomarker for disease progression and prognosis of patients with renal cell carcinoma.

BACKGROUND: In the clinic, how to stratify renal cell carcinoma (RCC) patients with different risks and to accurately predict their prognostic outcome remains a crucial issue. In this study, we assessed the expression and prognostic value of gankyrin in RCC patients. METHODS: The expression of gankyrin was examined in public databases and validated in specimens from two independent centers. The clinical practice and disease correlation of gankyrin in RCC were evaluated in RCC patients, various cell lines and an orthotopic RCC model. FINDINGS: Upregulation of gankyrin expression in RCC was corroborated in two independent cohorts. High gankyrin expression positively associated with disease progression and metastasis of RCC patients. A positive correlation between gankyrin and sunitinib-resistance was also observed in RCC cell lines and in an orthotopic RCC model. Kaplan-Meier analysis revealed that patients with higher gankyrin expression presented worse prognosis of RCC patients in the two cohorts. Gankyrin served as an independent prognostic factor for RCC patients even after multivariable adjustment by clinical variables. Time-dependent AUC and Harrell's c-index analysis presented that the incorporation of the gankyrin classifier into the current clinical prognostic parameters such as TNM stage, Fuhrman nuclear grade or SSIGN score achieved a greater accuracy than without it in predicting prognosis of RCC patients. All results were confirmed in randomized training and validation sets from the two patient cohorts. INTERPRETATION: Gankyrin can serve as a reliable biomarker for disease progression and for prognosis of RCC patients. Combining gankyrin with the current clinical parameters may help patient management. FUND: National Natural Science Foundation of China (No. 81773154, 81772747 and 81301861), Medical Discipline Construction Project of Pudong New Area Commission of Health and Family Planning (PWYgf2018-03), the Shanghai Medical Guidance (Chinese and Western Medicine) Science and Technology Support Project (No. 17411960200), Outstanding Leaders Training Program of Pudong Health Bureau of Shanghai (No. PWR12016-05).

Inhibition of PCSK9 protects against radiation-induced damage of prostate cancer cells.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a protein expressed primarily in the liver, formerly known to maintain plasma lipid homeostasis by regulating low-density lipoprotein receptor levels, and its exact role in the radioresistance of prostate cancer (PCa) remains unclear. We aim to investigate the function of PCSK9 in the radioresistance of PCa cells. METHODS: PCSK9 small interfering RNA (siRNA) was introduced into the PCa cells by transient transfection. Then, cells were exposed to ionizing radiation (IR) at indicated dose rates. Cell damage was detected using cell counting kit-8 (CCK-8) and Hoechest 33342/propidium iodide (PI) staining. Rhodamine-123 (Rho-123) dye was used to assay mitochondrial membrane potential alteration. Western blot was used to detect the apoptosis-related protein expression. RESULTS: PCSK9 siRNA treatment significantly protected PCa cells from IR-induced cell damage, including enhancing cell viability, reducing apoptosis, and inhibiting MMPs. Moreover, PCSK9 siRNA repressed the increase of cytochrome C (cyto C), caspase-3, and B-cell leukemia/lymphoma 2 (Bcl-2)-associated X (Bax) expressions induced by IR and promoted Bcl-2 expression, which might partially interpret the radioprotective role of PCSK9 siRNA in PCa cells. CONCLUSION: PCSK9 might impact on radiosensitivity through mitochondrial pathways and serve as a novel therapeutic target for PCa patients.

SMC1A promotes growth and migration of prostate cancer in vitro and in vivo.

Structural maintenance of chromosome 1 alpha (SMC1A) gene has been reported to be related to tumor development in some types of human cancers. However, the misregulation of SMC1A and its functions in castration-resistant prostate cancer (CRPC) have not been well understood. In the present study, we found that SMC1A was elevated in androgen-independent PCa cell lines PC-3 and DU-145 compared to androgen sensitive LNCap and 22RV1 cells by qPCR and western blot assay. Knockdown of SMC1A inhibited cell growth, colony formation and cell migration abilities of PC-3 and DU145 cells by MTT, colony formation and transwell assays, and affected cell cycle progression in PC-3 and DU145 cells by flow cytometry. Moreover, SMC1A knockdown significantly reduced tumor growth in vivo in a nude mouse model. Additionally, we also found that the expression of SMC1A gene was higher in prostate cancer tissues than in the adjacent normal tissues by immunohistochemical staining, and was positively correlated to tumor metastasis and recurrence by Oncomine database mining. Taken together, the present study indicates that SMC1A may play an important role in malignant transformation of PCa under conditions of androgen deprivation and act as a new target for PCa diagnosis and treatment.