USP39 promotes malignant proliferation and angiogenesis of renal cell carcinoma by inhibiting VEGF-A165b alternative splicing via regulating SRSF1 and SRPK1.

BACKGROUND: The benefit of targeted therapy for renal cell carcinoma (RCC) is largely crippled by drug resistance. Rapid disease progression and poor prognosis occur in patients with drug resistance. New treatments demand prompt exploration for clinical therapies. Ubiquitin-specific peptidase 39 (USP39) serves as the pro-tumor factor in several previous studies of other malignant tumors. To investigate the function and mechanism of USP39 in promoting malignant proliferation and angiogenesis of RCC. METHODS: We applied ONCOMINE database to analyze the correlation between USP39 expression level and the clinical characteristics of RCC. USP39 knockdown or overexpression plasmids were transfected into 786-O and ACHN cells. The HUVEC received cell supernatants of 786-O and ACHN cells with knockdown or overexpression USP39.The effect of USP39 on RCC was evaluated by MTT assay, cell cycle analysis, colony formation assay and tubule formation assay. The interaction between USP39 and VEGF-A alternative splicing was assessed by affinity purification and mass spectrometry, co-immunoprecipitation and Western blot assays. RESULTS: The mRNA expression level of USP39 in RCC was significantly higher than that in normal renal tissue (P < 0.001), and negatively correlated with the survival rate of RCC patients (P < 0.01). Silencing of USP39 in 786-O and ACHN cells inhibited cell proliferation and colony formation, and induced S phase arrest. USP39 overexpression significantly increased the number of tubules (P < 0.05) and branches (P < 0.01) formed by HUVEC cells, and USP39 knockdown produced an opposite effect (P < 0.05). The USP39 (101-565) fragment directly mediated its binding to SRSF1 and SRPK1, and promoted the phosphorylation of SRSF1 to regulate VEGF-A alternative splicing. USP39 knockdown upregulated the expression of VEGF-A165b, and USP39 overexpression downregulated the expression of VEGF-A165b significantly (both P < 0.05). CONCLUSION: USP39 acted as a pro-tumor factor by motivating the malignant biological processes of RCC, probably through inhibiting VEGF-A165b alternative splicing and regulating SRSF1 and SRPK1. USP39 may prove to be a potential therapeutic target for RCC.

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.

Preoperative neoadjuvant targeted therapy remodels intra-tumoral heterogeneity of clear-cell renal cell carcinoma and ferroptosis inhibition induces resistance progression.

Neoadjuvant tyrosine kinase inhibitor (TKI) therapy is an important treatment option for advanced renal cell carcinoma (RCC). Many RCC patients may fail to respond or be resistant to TKI therapy. We aimed to explore the key mechanisms of neoadjuvant therapy résistance. We obtained tumor samples from matched pre-treatment biopsy and post-treatment surgical samples and performed single-cell RNA sequencing. Sunitinib-resistant ccRCC cell lines were established. Ferroptosis was detected by ferrous ion and lipid peroxidation levels. Tumor growth and resistance to Sunitinib was validated in vitro and vivo. Immunohistochemistry was used to validate the levels key genes and lipid peroxidation. Multi-center cohorts were included, including TCGA, ICGC, Checkmate-025 and IMmotion151 clinical trial. Survival analysis was performed to identify the associated clinical and genomic variables. Intratumoral heterogeneity was first described in the whole neoadjuvant management. The signature of endothelial cells was correlated with drug sensitivity and progression-free survival. Ferroptosis was shown to be the key biological program in malignant cell resistance. We observed tissue lipid peroxidation was negatively correlated with IL6 and tumor response. TKI-resistant cell line was established. SLC7A11 knockdown promoted cell growth and lipid peroxidation, increased the ferroptosis level, and suppressed the growth of tumor xenografts significantly (P < 0.01). IL6 could reverse the ferroptosis and malignant behavior caused by SLC7A11 (-) via JAK2/STAT3 pathway, which was rescued by the ferroptosis inducer Erastin. Our data indicate that ferroptosis is a novel strategy for advanced RCC treatment, which activated by IL6, providing a new idea for resistance to TKIs.

Integrated analysis of tertiary lymphoid structures and immune infiltration in ccRCC microenvironment revealed their clinical significances: a multicenter cohort study.

BACKGROUND: Tertiary lymphoid structures (TLSs) serve as organized lymphoid aggregates that influence immune responses within the tumor microenvironment. This study aims to investigate the characteristics and clinical significance of TLSs and tumor-infiltrating lymphocytes (TILs) in clear cell renal cell carcinoma (ccRCC). METHODS: TLSs and TILs were analyzed comprehensively in 754 ccRCC patients from 6 academic centers and 532 patients from The Cancer Genome Atlas. Integrated analysis was performed based on single-cell RNA-sequencing datasets from 21 ccRCC patients to investigate TLS heterogeneity in ccRCC. Immunohistochemistry and multiplex immunofluorescence were applied. Cox regression and Kaplan-Meier analyses were used to reveal the prognostic significance. RESULTS: The study demonstrated the existence of TLSs and TILs heterogeneities in the ccRCC microenvironment. TLSs were identified in 16% of the tumor tissues in 113 patients. High density (>0.6/mm2) and maturation of TLSs predicted good overall survival (OS) (p<0.01) in ccRCC patients. However, high infiltration (>151) of scattered TILs was an independent risk factor of poor ccRCC prognosis (HR=14.818, p<0.001). The presence of TLSs was correlated with improved progression-free survival (p=0.002) and responsiveness to therapy (p<0.001). Interestingly, the combination of age and TLSs abundance had an impact on OS (p<0.001). Higher senescence scores were detected in individuals with immature TLSs (p=0.003). CONCLUSIONS: The study revealed the contradictory features of intratumoral TLSs and TILs in the ccRCC microenvironment and their impact on clinical prognosis, suggesting that abundant and mature intratumoral TLSs were associated with decreased risks of postoperative ccRCC relapse and death as well as favorable therapeutic response. Distinct spatial distributions of immune infiltration could reflect effective antitumor or protumor immunity in ccRCC.

Glycolysis drives STING signaling to facilitate dendritic cell antitumor function.

Activation of STING signaling in DCs promotes antitumor immunity. Aerobic glycolysis is a metabolic hallmark of activated DCs, but how the glycolytic pathway intersects with STING signaling in tumor-infiltrating DCs remains elusive. Here, we show that glycolysis drives STING signaling to facilitate DC-mediated antitumor immune responses. Tumor-infiltrating DCs exhibited elevated glycolysis, and blockade of glycolysis by DC-specific Ldha/Ldhb double deletion resulted in defective antitumor immunity. Mechanistically, glycolysis augmented ATP production to boost STING activation and STING-dependent DC antitumor functions. Moreover, DC-intrinsic STING activation accelerated HIF-1α-mediated glycolysis and established a positive feedback loop. Importantly, glycolysis facilitated STING-dependent DC activity in tissue samples from patients with non-small cell lung cancer. Our results provide mechanistic insight into how the crosstalk of glycolytic metabolism and STING signaling enhances DC antitumor activity and can be harnessed to improve cancer therapies.

Single-cell RNA-seq integrated with multi-omics reveals SERPINE2 as a target for metastasis in advanced renal cell carcinoma.

Tumor growth, metastasis and therapeutic response are believed to be regulated by the tumor and its microenvironment (TME) in advanced renal cell carcinoma (RCC). However, the mechanisms underlying genomic, transcriptomic and epigenetic alternations in RCC progression have not been completely defined. In this study, single-cell RNA-sequencing (scRNA-seq) data were obtained from eight tissue samples of RCC patients, including two matched pairs of primary and metastatic sites (lymph nodes), along with Hi-C, transposable accessible chromatin by high-throughput (ATAC-seq) and RNA-sequencing (RNA-seq) between RCC (Caki-1) and human renal tubular epithelial cell line (HK-2). The identified target was verified in clinical tissue samples (microarray of 407 RCC patients, TMA-30 and TMA-2020), whose function was further validated by in vitro and in vivo experiments through knockdown or overexpression. We profiled transcriptomes of 30514 malignant cells, and 14762 non-malignant cells. Comprehensive multi-omics analysis revealed that malignant cells and TME played a key role in RCC. The expression programs of stromal cells and immune cells were consistent among the samples, whereas malignant cells expressed distinct programs associated with hypoxia, cell cycle, epithelial differentiation, and two different metastasis patterns. Comparison of the hierarchical structure showed that SERPINE2 was related to these NNMF expression programs, and at the same time targeted the switched compartment. SERPINE2 was highly expressed in RCC tissues and lowly expressed in para-tumor tissues or HK-2 cell line. SERPINE2 knockdown markedly suppressed RCC cell growth and invasion, while SERPINE2 overexpression dramatically promoted RCC cell metastasis both in vitro and in vivo. In addition, SERPINE2 could activate the epithelial-mesenchymal transition pathway. The above findings demonstrated that the role of distinct expression patterns of malignant cells and TME played a distinct role in RCC progression. SERPINE2 was identified as a potential therapeutic target for inhibiting metastasis in advanced RCC.

ENO2 affects the EMT process of renal cell carcinoma and participates in the regulation of the immune microenvironment.

Clear cell renal cell carcinoma (ccRCC) is a frequent malignant tumor of the kidney which has a dismal prognosis. At present, targeted therapies and immunotherapy have achieved significant results; however, the overall survival rate of patients with ccRCC remains unacceptably poor. It is therefore necessary to find novel therapeutic and diagnostic targets for ccRCC. It has been reported that enolase 2 (ENO2) is an oncogene, although its function in the immune microenvironment and in the growth of ccRCC has yet to be fully elucidated. The present study analyzed the data of patients with ccRCC both from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases, and from clinical samples obtained from Third Affiliated Hospital of the Second Military Medical University to investigate the role of ENO2 in the progression of ccRCC and the correlation between ENO2 and certain clinical features. It was found that the expression of ENO2 was elevated both in patients with ccRCC retrieved from the GEO and TCGA databases and in clinical ccRCC samples obtained from Third Affiliated Hospital of the Second Military Medical University. In addition, the prognosis of patients was poorer when ENO2 was highly expressed. Gene Ontology (GO) analysis and Gene Set Enrichment Analysis (GSEA) confirmed that ENO2 participated in the regulation of various pathways in ccRCC. In vitro experiments including Cell Counting Kit­8 cell proliferation assay, Transwell and Matrigel assays confirmed that ENO2 could promote the proliferation and migration of ccRCC cells. Furthermore, a number of immunosuppressive indicators were identified that positively correlated with ENO2 expression. In conclusion, the present study revealed that ENO2 expression promotes the proliferation, invasion and migration of ccRCC cells, and may serve as a novel predictor to evaluate prognosis and the efficacy of immune checkpoint blockade treatment for patients with ccRCC.

Molecular subtyping and characterization of clear cell renal cell carcinoma by tumor differentiation trajectories.

Previous bulk RNA sequencing or whole genome sequencing on clear cell renal cell carcinoma (ccRCC) subtyping mainly focused on ccRCC cell origin or the complex tumor microenvironment (TME). Based on the single-cell RNA sequencing (scRNA-seq) data of 11 primary ccRCC specimens, cancer stem-cell-like subsets could be differentiated into five trajectories, whereby we further classified ccRCC cells into three groups with diverse molecular features. These three ccRCC subgroups showed significantly different outcomes and potential targets to tyrosine kinase inhibitors (TKIs) or immune checkpoint inhibitors (ICIs). Tumor cells in three differentiation directions exhibited distinct interactions with other subsets in the ccRCC niches. The subtyping model was examined through immunohistochemistry staining in our ccRCC cohort and validated the same classification effect as the public patients. All these findings help gain a deeper understanding about the pathogenesis of ccRCC and provide useful clues for optimizing therapeutic schemes based on the molecular subtype analysis.

Impact of interaction networks of B cells with other cells on tumorigenesis, progression and response to immunotherapy of renal cell carcinoma: A review.

Ample evidence indicates that the development and progression of renal cell carcinoma (RCC) are complex pathological processes involving interactions between tumor cells, immune cells and stromal components. Tumor infiltrated immune cells determine whether tumor advancement is promoted or inhibited. Among them, infiltrated B lymphocytes are present in all stages of RCC, playing a major role in determining tumor formation and advancement, as an essential part in the tumor microenvironment (TME). Although the advent of targeted and immune therapies has remarkably improved the survival of patients with advanced RCC, few cases can achieve complete response due to drug resistance. In this review article, we intend to summary the recent studies that outline the interaction networks of B cells with other cells, discuss the role of B cells in RCC development and progression, and assess their impact on RCC immunotherapy.

"Zero ischemia" laparoscopic partial nephrectomy by high-power GreenLight laser enucleation for renal carcinoma: A single-center experience.

BACKGROUND: Laparoscopic partial nephrectomy has been widely used in renal cell carcinoma treatment. The efficacy of GreenLight laser on Laparoscopic partial nephrectomy is still unknown. AIM: To present the first series of laparoscopic partial nephrectomy (LPN) by GreenLight laser enucleation without renal artery clamping. Due to the excellent coagulation and hemostatic properties of the laser, laser-assisted LPN (LLPN) makes it possible to perform a "zero ischemia" resection. METHODS: Fifteen patients with T1a exogenous renal tumors who received high-power GreenLight laser non-ischemic LPN in our hospital were retrospectively analyzed. All clinical information, surgical and post-operative data, complications, pathological and functional outcomes were analyzed. RESULTS: Surgery was successfully completed in all patients, and no open or radical nephrectomy was performed. The renal artery was not clamped, leading to no ischemic time. No blood transfusions were required, the average hemoglobin level ranged from 96.0 to 132.0 g/L and no postoperative complications occurred. The mean operation time was 104.3 ± 8.2 min. The postoperative removal of negative pressure drainage time ranged from 5.0 to 7.0 d, and the mean postoperative hospital stay was 6.5 ± 0.7 d. No serious complications occurred. Postoperative pathological results showed clear cell carcinoma in 12 patients, papillary renal cell carcinoma in 2 patients, and hamartoma in 1 patient. The mean creatinine level was 75.0 ± 0.8 µmol/L (range 61.0-90.4 µmol/L) at 1 mo after surgery, and there were no statistically significant differences compared with pre-operation (P > 0.05). The glomerular filtration rate ranged from 45.1 to 60.8 mL/min, with an average of 54.0 ± 5.0 mL/min, and these levels were not significantly different from those before surgery (P > 0.05). CONCLUSION: GreenLight laser has extraordinary cutting and sealing advantages when used for small renal tumors (exogenous tumors of stage T1a) during LPN. However, use of this technique can lead to the generation of excessive smoke.

Heterogeneity of tumor microenvironment is associated with clinical prognosis of non-clear cell renal cell carcinoma: a single-cell genomics study.

Non-clear renal cell carcinomas (nccRCCs) are less frequent in kidney cancer with histopathological heterogeneity. A better understanding of the tumor biology of nccRCC can provide more effective treatment paradigms for different subtypes. To reveal the heterogeneity of tumor microenvironment (TME) in nccRCC, we performed 10x sing-cell genomics on tumor and normal tissues from patients with papillary renal cell carcinoma (pRCC), chromophobe RCC (chrRCC), collecting duct carcinoma (CDRCC) and sarcomatoid RCC (sarRCC). 15 tissue samples were finally included. 34561 cells were identified as 16 major cell clusters with 34 cell subtypes. Our study presented the sing-cell landscape for four types of nccRCC, and demonstrated that CD8+ T cells exhaustion, tumor-associated macrophages (TAMs) and sarcomatoid process were the pivotal factors in immunosuppression of nccRCC tissues and were closely correlated with poor prognosis. Abnormal metabolic patterns were present in both cancer cells and tumor-infiltrating stromal cells, such as fibroblasts and endothelial cells. Combined with CIBERSORTx tool, the expression data of bulk RNA-seq from TCGA were labeled with cell types of our sing-cell data. Calculation of the relative abundance of cell types revealed that greater proportion of exhausted CD8+ T cells, TAMs and sarRCC derived cells were correlated with poor prognosis in the cohort of 274 nccRCC patients. To the best of our knowledge, this is the first study that provides a more comprehensive sight about the heterogeneity and tumor biology of nccRCC, which may potentially facilitate the development of more effective therapies for nccRCC.

[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].

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).

PPP5C promotes cell proliferation and survival in human prostate cancer by regulating of the JNK and ERK1/2 phosphorylation.

BACKGROUND: Prostate cancer (PCa) is one of the most common malignancies and a major leading cause of cancer-related deaths in males. And it is necessary to explore new molecular targets to enhance diagnosis and treatment level of the PCa. Serine/threonine protein phosphatase 5 (PPP5C) is a vital molecule that Involve in complex cell physiological activity. PURPOSE: The objective of this study was to detecte the expression level of PPP5C in the tissue of prostate cancer patients and further discussed the PPP5C biological function and mechanisms on the PCa. METHODS: The expression level of PPP5C was analyzed by immunohistochemistry and ONCOM-INE datasets. Lentivirus-mediated short hairpin RNA (shRNA) was constructed to silence the expression of PPP5C in prostate cancer cell. Cell viability and proliferation were measured using MTT and colony formation, and the cell cycle and apoptosis was analyszed by flow cytometry. The changes of downstream protein level and protein phosphorylation level were detected by western blot. RESULTS: PPP5C was highly expressed in PCa tissue as analyzed by immunohistochemistry and ONCOMINE datasets. PPP5C Knockdown inhibited cell proliferation and colony formation in PCa cells. Flow cytometry analysis showed that DU145, PC3 and 22RV1 PCa cells deprived of PPP5C were arrested in G0/G1 phase and became apoptotic. Western blot analysis indicated that PPP5C knockdown could promote JNK and ERK phosphorylation. CONCLUSION: Our study indicated that the PPP5C may become a new potential diagnostic biomarker and therapeutic target for the PCa.

α-Viniferin activates autophagic apoptosis and cell death by reducing glucocorticoid receptor expression in castration-resistant prostate cancer cells.

Prostate cancer (PCa) is one of the most commonly diagnosed urological malignancies. However, there are limited therapies for PCa patients who develop biochemical recurrence after androgen deprivation therapy (ADT). In the present study, we investigated the therapeutic efficacy and mechanism of α-Viniferin (KCV), an oligostilbene of trimeric resveratrol, against human PCa cells and found that it markedly inhibited the proliferation of LNCaP, DU145, and PC-3 cancer cells in a time- and dose-dependent manner, and had a strong cytotoxicity in non-androgen-dependent PCa cells. In addition, KCV inhibited AR downstream expression in LNCaP cells, and inhibited activation of GR signaling pathway in DU145 and PC-3. Further investigation indicated that KCV could induce cancer cell apoptosis through AMPK-mediated activation of autophagy, and inhibited GR expression in castration-resistant prostate cancer(CRPC). These findings suggest that KCV may prove to be a novel and effective therapeutic agent for the treatment of CRPC.

Epithelial-mesenchymal transition induced by GRO-α-CXCR2 promotes bladder cancer recurrence after intravesical chemotherapy.

Non-muscle invasive bladder cancers (NMIBC) are typically treated by transurethral resection with intravesical chemotherapy. However, the post-therapeutic incidence of tumor recurrence and progression to muscle invasive disease is high, and the underlying mechanism(s) remains unknown. In this study, we observed that recurrent bladder cancer cells exhibit a mesenchymal phenotype, which is initiated by the autocrine GRO-α signaling. Mechanically, the chemotherapeutic drug epidoxorubicin induces GRO-α expression in primary bladder cancer cells at G1/S phase via p38-dependent activation of NF-κB. GRO-α phosphorylation of Snail on Ser246 supports Snail's accumulation in the nucleus, and thereby promotes transcription repression activity of Snail from E-cadherin promoters. In accordance, disrupting the GRO-α-Snail axis in NMIBC represents a promising alternative to prevent post-therapeutic tumor progression and recurrence.

High expression of PDLIM5 facilitates cell tumorigenesis and migration by maintaining AMPK activation in prostate cancer.

PDZ and LIM domain 5 (PDLIM5) is a cytoskeleton-associated protein and has been shown to bind to a variety of proteins through its specific domain, thereby acting to regulate cell migration and tumor progression. Here, we found that PDLIM5 was abnormally upregulated in prostate cancer (PCa) tissues as compared with that in normal prostate tissue. ONCOMINE microarray data mining showed that PDLIM5 was closely correlated with the prognosis of PCa in terms of Gleason score, tumor metastasis and biochemical recurrence. Lentivirus-mediated short hairpin RNA (shRNA) knockdown of PDLIM5 inhibited cell proliferation and colony formation, arrested hormone independent PCa cells DU145 and PC-3 in G2/M phase, and induced apoptosis. Meanwhile, silencing PDLIM5 inhibited migration and invasion of tumor cells by reversing the mesenchymal phenotype and a similar result was confirmed in a xenograft nude mouse model. Finally, we found PDLIM5 plays a crucial role in regulating malignant tumor cell proliferation, invasion and migration by binding to AMPK and affecting its activation and degradation, and may therefore prove to be a potential oncogenic gene in the development and progression of PCa.

Disruption of serine/threonine protein phosphatase 5 inhibits tumorigenesis of urinary bladder cancer cells.

Serine/threonine protein phosphatase 5 (PPP5C) is a member of the protein serine/threonine phosphatase family and has been shown to participate in multiple signaling cascades and tumor progression. We found that PPP5C was highly expressed in bladder cancer tissues compared to normal urothelial tissues, and positively correlated to tumor stages through ONCOMINE microarray data mining. Knockdown of PPP5C via a lentivirus-mediated short hairpin RNA (shRNA) markedly inhibited cell proliferation and colony formation. Flow cytometric analysis showed that PPP5C-deficient T24 and BT5637 bladder cancer cells were arrested in G0/G1 phase and induced apoptosis. In addition, tumor growth was inhibited in vivo in a xenograft nude mouse model. Further studies indicated that knockdown of PPP5C downregulated c-myc and CDK4, whereas upregulated p27, BAD and Beclin1. These results suggest that PPP5C is associated with bladder cancer (BCa) and plays an oncogenic role in the development and progression of bladder cancer.