Combination of quantitative IMP3 and tumor stage: a new system to predict metastasis for patients with localized renal cell carcinomas

Knockdown of PIK3R6 impedes the onset and advancement of clear cell renal cell carcinoma

In this research, we investigated the role of PIK3R6, a regulatory subunit of PI3Kγ, known for its tumor-promoting properties, in clear cell renal cell carcinoma (CCRCC). Utilizing the UALCAN website, we found PIK3R6 upregulated in CCRCC, correlating with lower survival rates. We compared PIK3R6 expression in CCRCC tumor tissues and adjacent normal tissues using immunohistochemistry. Post RNA interference-induced knockdown of PIK3R6 in 786-O and ACHN cell lines, we performed CCK-8, colony formation, Edu staining, flow cytometry, wound healing, and transwell assays. Results showed that PIK3R6 silencing reduced cell proliferation, migration, and invasion, and induced G0/G1 phase arrest and apoptosis. Molecular analysis revealed decreased CDK4, Cyclin D1, N-cadherin, Vimentin, Bcl-2, p-PI3K and p-AKT, with increased cleaved caspase-3, Bax, and E-cadherin levels in CCRCC cells. Moreover, inhibiting PIK3R6 hindered tumor growth. These findings suggest a significant role for PIK3R6 in CCRCC cell proliferation and metastasis, presenting it as a potential therapeutic target.

The role of RNA-modifying proteins in renal cell carcinoma

Gene expression is one of the most critical cellular processes. It is controlled by complex mechanisms at the genomic, epigenomic, transcriptomic, and proteomic levels. Any aberration in these mechanisms can lead to dysregulated gene expression. One recently discovered process that controls gene expression includes chemical modifications of RNA molecules by RNA-modifying proteins, a field known as epitranscriptomics. Epitranscriptomics can regulate mRNA splicing, nuclear export, stabilization, translation, or induce degradation of target RNA molecules. Dysregulation in RNA-modifying proteins has been found to contribute to many pathological conditions, such as cancer, diabetes, obesity, cardiovascular diseases, and neurological diseases, among others. This article reviews the role of epitranscriptomics in the pathogenesis and progression of renal cell carcinoma. It summarizes the molecular function of RNA-modifying proteins in the pathogenesis of renal cell carcinoma.

Therapeutic blocking of VEGF binding to neuropilin-2 diminishes PD-L1 expression to activate antitumor immunity in prostate cancer

Prostate cancers are largely unresponsive to immune checkpoint inhibitors (ICIs), and there is strong evidence that programmed death-ligand 1 (PD-L1) expression itself must be inhibited to activate antitumor immunity. Here, we report that neuropilin-2 (NRP2), which functions as a vascular endothelial growth factor (VEGF) receptor on tumor cells, is an attractive target to activate antitumor immunity in prostate cancer because VEGF-NRP2 signaling sustains PD-L1 expression. NRP2 depletion increased T cell activation in vitro. In a syngeneic model of prostate cancer that is resistant to ICI, inhibition of the binding of VEGF to NRP2 using a mouse-specific anti-NRP2 monoclonal antibody (mAb) resulted in necrosis and tumor regression compared with both an anti-PD-L1 mAb and control immunoglobulin G. This therapy also decreased tumor PD-L1 expression and increased immune cell infiltration. We observed that the NRP2, VEGFA, and VEGFC genes are amplified in metastatic castration-resistant and neuroendocrine prostate cancer. We also found that individuals with NRP2^High PD-L1^High metastatic tumors had lower androgen receptor expression and higher neuroendocrine prostate cancer scores than other individuals with prostate cancer. In organoids derived from patients with neuroendocrine prostate cancer, therapeutic inhibition of VEGF binding to NRP2 using a high-affinity humanized mAb suitable for clinical use also diminished PD-L1 expression and caused a substantial increase in immune-mediated tumor cell killing, consistent with the animal studies. These findings provide justification for the initiation of clinical trials using this function-blocking NRP2 mAb in prostate cancer, especially for patients with aggressive disease.

Insulin-like growth factor-2 mRNA-binding protein 3 promotes cell migration, invasion, and epithelial-mesenchymal transition of esophageal squamous cell carcinoma cells by targeting zinc finger E-box-binding homeobox 1 mRNA

The role and mechanism of insulin-like growth factor-2 mRNA-binding protein 3 (IGF2BP3) in the metastasis of esophageal squamous cell carcinoma (ESCC) remain unclear. In this study, IGF2BP3 mRNA and protein expression levels were evaluated in ESCC tissues. Small interfering RNAs (siRNAs), plasmid overexpression, and stable lentivirus transfection were used to manipulate intracellular IGF2BP3 expression levels. The role of IGF2BP3 in ESCC tumorigenesis was investigated in vitro and in vivo. IGF2BP3 target transcripts were detected, and the acetylation effect ratios of the IGF2BP3 promoter region by H3K27ac were determined. IGF2BP3 mRNA expression levels were significantly higher in ESCC tissues than in normal esophageal tissues. Increased IGF2BP3 expression levels were detected in node-negative ESCC tissues and correlated with greater lesion depth in ESCC. Overexpression of IGF2BP3 promoted ESCC development in vitro and in vivo, and IGF2BP3 knockdown caused an opposite effect. IGF2BP3 was found to directly bind to the zinc finger E-box-binding homeobox 1 (Zeb1) mRNA, and the downregulation of IGF2BP3 reduced the stability of Zeb1 mRNA. IGF2BP3 induced epithelial-mesenchymal transition in ESCC cells in a Zeb1-dependent manner. IGF2BP3 was transcriptionally activated in ESCC cell lines via H3K27 acetylation. Our results demonstrate that IGF2BP3 plays a vital role in ESCC cell proliferation, invasion, and metastasis and is a potential therapeutic target for treating ESCC.

Prognostic Value of IGF2 mRNA-Binding Protein 3 (IGF2BP3) Intratumoral Expression in Melanoma Patients at the Time of Diagnosis: Comparative Analysis of RT-qPCR Versus Immunohistochemistry

Simple Summary

Around 80% of skin cancer deaths are due to melanoma. An accurate prognosis of melanoma clinical behavior from primary tumors is important for therapeutic patient management, currently based on histopathological features. The aim of our retrospective study was to investigate the clinical significance of IGF2BP3 mRNA and protein expression in melanoma progression and to evaluate which quantification method, RT-qPCR or immunohistochemistry, provides a more reliable prognostic value of IGF2BP3 expression in primary tumors. We found that IGF2BP3 mRNA expression correlated better with clinicopathologic melanoma features than the corresponding proteins and that patients with higher IGF2BP3 mRNA levels were at more risk for earlier development of metastasis, confirming its impact on melanoma survival. Our findings support the use of IGF2BP3 mRNA levels as an independent prognostic biomarker and the implementation of its RT-qPCR analysis for routine melanoma assessment, even for the earliest stages, to improve melanoma clinical outcomes and individualized treatment.

Abstract

Screening for prognostic biomarkers is crucial for clinical melanoma management. Insulin-like growth factor-II mRNA-binding protein 3 (IGF2BP3) has emerged as a potential melanoma diagnostic and prognostic biomarker. It is commonly tested by immunohistochemistry (IHC). Our study retrospectively examines IGF2BP3 mRNA and protein expression in primary melanomas, their correlation with clinicopathologic factors, clinical outcome, and selected miRNAs expression, and their efficiency in predicting melanoma progression and survival. RT-qPCR and IHC on IGF2BP3 expression were performed in 61 cryopreserved and 63 formalin-fixed paraffin-embedded primary melanomas, respectively, and correlated to clinicopathologic factors, distant metastasis-free survival (DMFS), and melanoma -specific survival (MSS). The correlation between RT-qPCR and IHC was significant but moderate. IGF2BP3 mRNA showed a stronger association with clinicopathologic factors (Breslow thickness, ulceration, mitosis rate, growth phase, development of metastasis, and melanoma-specific survival) than its protein counterpart. Interestingly, higher IGF2BP3 mRNA expression was detected in primary melanomas that further metastasized to distant sites and was an independent prognostic factor for the risk of unfavorable DMFS and MSS. RT-qPCR outperformed IHC in sensitivity and in predicting worse clinical outcomes. Therefore, RT-qPCR may successfully be implemented for routine IGF2BP3 assessing for the selection of melanoma patients with a higher risk of developing distant metastasis and dying of melanoma.

MicroRNA as a Biomarker for Diagnostic, Prognostic, and Therapeutic Purpose in Urinary Tract Cancer

The incidence of urologic cancers, including kidney, upper tract urothelial, and bladder malignancies, is increasing globally, with a high percentage of cases showing metastasis upon diagnosis and low five-year survival rates. MicroRNA (miRNA), a small non-coding RNA, was found to regulate the expression of oncogenes and tumor suppressor genes in several tumors, including cancers of the urinary system. In the current review, we comprehensively discuss the recently reported up-or down-regulated miRNAs as well as their possible targets and regulated pathways involved in the development, progression, and metastasis of urinary tract cancers. These miRNAs represent potential therapeutic targets and diagnostic/prognostic biomarkers that may help in efficient and early diagnosis in addition to better treatment outcomes.

Risk Scores Based on Six Survival-Related RNAs in a Competing Endogenous Network Composed of Differentially Expressed RNAs Between Clear Cell Renal Cell Carcinoma Patients Carrying Wild-Type or Mutant Von Hippel-Lindau Serve Well to Predict Malignancy and Prognosis

Clear cell renal cell carcinoma (ccRCC) carrying wild-type Von Hippel–Lindau (VHL) tumor suppressor are more invasive and of high morbidity. Concurrently, competing endogenous RNA (ceRNA) network has been suggested to play an important role in ccRCC malignancy. In order to understand why the patients carrying wild-type VHL gene have high degrees of invasion and morbidity, we applied bioinformatics approaches to identify 861 differentially expressed RNAs (DE-RNAs) between patients carrying wild-type and patients carrying mutant VHL from The Cancer Genome Atlas (TCGA) database, established a ceRNA network including 122 RNAs, and elected six survival-related DE-RNAs including Linc00942, Linc00858, RP13_392I16.1, hsa-miR-182-5p, hsa-miR-183-5p, and PAX3. Examining clinical samples from our hospital revealed that patients carrying wild-type VHL had significantly higher levels of all six RNAs than those carrying mutant VHL. Patients carrying wild-type VHL had significantly higher risk scores, which were calculated based on expression levels of all six RNAs, than those carrying mutant VHL. Patients with higher risk scores had significantly shorter survival times than those with lower risk scores. Therefore, the risk scores serve well to predict malignancy and prognosis.

Targeting POLE2 Creates a Novel Vulnerability in Renal Cell Carcinoma via Modulating Stanniocalcin 1

Objective

The aim of this study is to investigate the biological functions and the underlying mechanisms of DNA polymerase epsilon subunit 2 (POLE2) in renal cell carcinoma (RCC).

Methods

The datasets of POLE2 expression in The Cancer Genome Atlas Kidney Clear Cell Carcinoma (TCGA-KIRC) and International Cancer Genome Consortium (ICGC) databases was selected and the correlation between POLE2 and various clinicopathological parameters was analyzed. The POLE2 expression in RCC tissues was examined by immunohistochemistry. The POLE2 knockdown cell lines were constructed. In vitro and in vivo experiments were carried out to investigate the function of POLE2 on cellular biology of RCC, including cell viability assay, clone formation assay, flow cytometry, wound-healing assay, Transwell assay, qRT-PCR, Western blot, etc. Besides, microarray, co-immunoprecipitation, rescue experiment, and Western blot were used to investigate the molecular mechanisms underlying the functions of POLE2.

Results

POLE2 was overexpressed in RCC tissues, and high expression of POLE2 was correlated with poor prognosis of RCC. Furthermore, knockdown of POLE2 significantly inhibited cell proliferation, migration, and facilitated apoptosis in vitro. In vivo experiments revealed that POLE2 attenuated RCC tumorigenesis and tumor growth. we also illuminated that stanniocalcin 1 (STC1) was a downstream gene of POLE2, which promoted the occurrence and development of RCC. Besides, knockdown of POLE2 significantly upregulated the expression levels of Bad and p21 while the expression levels of HSP70, IGF-I, IGF-II, survivin, and sTNF-R1 were significantly downregulated. Western blot analysis also showed that knockdown of POLE2 inhibited the expression levels of Cancer-related pathway proteins including p-Akt, CCND1, MAPK9, and PIK3CA.

Conclusion

Knockdown of POLE2 attenuates RCC cells proliferation and migration by regulating STC1, suggesting that POLE2-STC1 may become a potential target for RCC therapy.

Integrated analysis of the functions of RNA binding proteins in clear cell renal cell carcinoma

RNA binding proteins (RBPs) dysregulation is involved in the processes of various tumors. However, the roles of RBPs in clear cell renal cell carcinoma (ccRCC) remain poorly understand. In present study, we first performed consensus clustering and identified two clusters, of which cluster 2 was closely correlated with the malignancy of ccRCC. Differentially expressed RBPs between normal and tumor tissues were obtained, comprising 71 up-regulated and 44 down-regulated ones. Then, ten hub genes were selected and validated using The Human Protein Atlas database and receiver operating characteristic curves, showing good diagnostic value for cancers. Besides, we identified ten RBPs with the most useful prognostic values, and were used to construct a risk score model. The model could be used to stratify patients with different prognosis and phenotype distributions. The model showed good performance and can be used as a complementation for clinical factors to guide clinical practice in the future.

Long Non-Coding RNA TUG1 Promotes Cell Proliferation and Inhibits Cell Apoptosis, Autophagy in Clear Cell Renal Cell Carcinoma via MiR-31-5p/FLOT1 Axis

Purpose

Clear cell renal cell carcinoma (ccRCC) is a common urological carcinoma in adults. Long non-coding RNA (lncRNA) taurine-upregulated gene 1 (TUG1) has been reported to be involved in the progression of diverse human cancers, including renal cell carcinoma (RCC). However, the biological mechanism of TUG1 was rarely reported in ccRCC.

Methods

The levels of TUG1, microRNA miR-31-5p and flotillin 1 (FLOT1) in ccRCC tissues and cells were detected by qRT-PCR. The interactions between miR-31-5p and TUG1 or FLOT1 were predicted by starBase v2.0 and TargetScan, respectively, which were further validated by RIP assay and RNA pull-down assay. Cell counting kit-8 (CCK-8), flow cytometry and Western blot were used to assess the effects of TUG1 on cell viability, apoptosis rate and the relative protein expression levels in ccRCC cells. In addition, the xenograft tumor assay was conducted to further verify the functions of TUG1 in ccRCC in vivo.

Results

TUG1 was dramatically up-regulated in ccRCC tissues and cells. TUG1 silencing inhibited cell proliferation and promoted cell apoptosis, autophagy in 786-0 and A498 cells. In addition, TUG1 depletion repressed tumor growth in vivo. Moreover, miR-31-5p was validated as a direct target of TUG1, and microRNA miR-31-5p inhibitor mitigated the effects of TUG1 knockdown on ccRCC progression. Furthermore, FLOT1 was verified to be negatively interacted with miR-31-5p. FLOT1 overexpression attenuated miR-31-5p-mediated inhibitory effect on cell proliferation and promotion effects on cell apoptosis, autophagy. The restoration experiment implicated that TUG1 positively modulated FLOT1 expression by sponging miR-31-5p.

Conclusion

All data demonstrated that TUG1 promotes cell proliferation and inhibits cell apoptosis and autophagy in ccRCC by miR-31-5p/FLOT1 axis, which may provide a therapeutic target for ccRCC patients.

The Oncogenic Functions of Insulin-like Growth Factor 2 mRNA-Binding Protein 3 in Human Carcinomas

IGF2BP3 (also known as IMP3, KOC), a member of the insulin-like growth factor mRNA-binding protein family (IMPs), has been a research target in recent studies of promoting embryo development and exacerbating cancer. IGF2BP3 is ubiquitously expressed in early embryogenesis stages but limited in postembryonic stages, which is important in many physiological aspects such as stem cell renewal, morphological development and metabolism. A large number of studies show that IGF2BP3 interacts with many kinds of non-coding RNAs and proteins to promote cancer cell proliferation and metastasis and inhibit cancer cell apoptosis. As IGF2BP3 is highly expressed in advanced cancers and associated with poor overall survival rates of patients, it may be a potential molecular marker in cancer diagnosis for the detection of cancerous tissues and an indicator of cancer stages. Therefore, anti-IGF2BP3 drugs or monoclonal antibodies are expected as new therapeutic methods in cancer treatment. This review summarizes recent findings among IGF2BP3, RNA and proteins in cancer processes, with a focus on its cancer-promoting mechanisms and potential application as a new biomarker for cancer diagnosis and treatment.

Expression of CREPT is associated with poor prognosis of patients with renal cell carcinoma

Cell-cycle-associated and expression-elevated protein in tumor (CREPT) functions as a cell cycle modulator that enhances the transcription of cyclin D1 by interacting with RNA polymerase II. CREPT has been identified to be overexpressed in various human cancer types; however, the expression and significance of CREPT in renal cell carcinoma (RCC) has remained largely elusive. In the present study, increased expression of CREPT was identified in 46.7% RCC tissues compared with adjacent normal tissue (31.1%; P=0.032) using immunohistochemistry. Furthermore, overexpression of CREPT was significantly associated with the Tumor-Node-Metastasis stage (χ²=11.967, P=0.001) and Fuhrman grade (χ²=15.453, P<0.001). In addition, increased expression of CREPT was associated with poor overall survival (P=0.021) and disease-free survival (P=0.015) of patients according to Kaplan-Meier analysis. Cellular function assays demonstrated that knockdown of CREPT in the 786-O and 769P RCC cell lines suppressed their proliferative, colony formation, migratory and invasive capacity and led to cell cycle arrest in the G1 phase. In addition, the western blotting analysis demonstrated that CREPT may control the cell cycle through downregulation of cyclin D1 and c-myc. Collectively, the overexpression of CREPT was indicated to be a negative prognostic factor for RCC, and CREPT may serve as a novel therapeutic target for the treatment of RCC.

The anti-apoptotic effect on cancer-associated fibroblasts of B7-H3 molecule enhancing the cell invasion and metastasis in renal cancer

Background: Renal cancer is one of the most common malignancies. However, the mechanisms underlying its development are still ambiguous. B7-H3 has been described as an important tumor antigen in various human tumors. An abnormal high expression of B7-H3 molecules is often observed in tumor cells and tumor stromal cells in the tumor microenvironment. On the basis of the above findings, we hypothesized that cancer-associated fibroblasts (CAFs) clustered in the renal cell microenvironment can survive for a long time with the anti-apoptotic effect of B7-H3, and then secrete cytokines to enhance the malignant behavior of renal cancer cells. Methods: The expression of B7-H3 protein in CAFs was detected in renal cancer tissues. Then, the CAFs cells were stably transfected with shRNA and their expression was silenced to determine the role of B7-H3 in CAFs. Western blot was used to detect the expression of apoptosis-related proteins, hepatocyte growth factor (HGF) protein and stromal cell-derived factor-1 (CXCL12) protein. CAF-NC cells and CAFs-shRNA cells were co-cultured with A498 cells to assess the biological function changes of A498. Results: A group of CAFs were found with B7-H3 expression in renal cancer. B7-H3 can stimulate CAFs to secrete HGF and Cxcl-12, and has strong anti-apoptotic effect on CAFs. We also found that CAFs-NC promotes the proliferation, invasion and migration of A498 cells in vitro and promotes the tumor formation of A498 in vivo. Conclusion: B7-H3+ CAFs promote the invasion and metastasis in renal cancer.

Oncogene and therapeutic target analyses in atypical fibroxanthomas and pleomorphic dermal sarcomas

BACKGROUND

Until now, almost nothing is known about the tumorigenesis of atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS). Our hypothesis is that AFX is the non-infiltrating precursor lesion of PDS.

MATERIALS AND METHODS

We performed the world-wide most comprehensive immunohistochemical and mutational analysis in well-defined AFX (n=5) and PDS (n=5).

RESULTS

In NGS-based mutation analyses of selected regions by a 17 hotspot gene panel of 102 amplicons we could detect TP53 mutations in all PDS as well as in the only analyzed AFX and PDS of the same patient. Besides, we detected mutations in the CDKN2A, HRAS, KNSTRN and PIK3CA genes.Performing immunohistochemistry for CTNNB1, KIT, CDK4, c-MYC, CTLA-4, CCND1, EGFR, EPCAM, ERBB2, IMP3, INI-1, MKI67, MDM2, MET, p40, TP53, PD-L1 and SOX2 overexpression of TP53, CCND1 and CDK4 was seen in AFX as well as in PDS. IMP3 was upregulated in 2 AFX (weak staining) and 4 PDS (strong staining).FISH analyses for the genes FGFR1, FGFR2 and FGFR3 revealed negative results in all tumors.

CONCLUSIONS

UV-induced TP53 mutations as well as CCND1/CDK4 changes seem to play essential roles in tumorigenesis of PDS. Furthermore, we found some more interesting mutated genes in other oncogene pathways (activating mutations of HRAS and PIK3CA). All AFX and PDS investigated immunohistochemically presented with similar oncogene expression profiles (TP53, CCND1, CDK4 overexpression) and the single case with an AFX and PDS showed complete identical TP53 and PIK3CA mutation profiles in both tumors. This reinforces our hypothesis that AFX is the non-infiltrating precursor lesion of PDS.

Translational Dysregulation in Cancer: Molecular Insights and Potential Clinical Applications in Biomarker Development

Although transcript levels have been traditionally used as a surrogate measure of gene expression, it is increasingly recognized that the latter is extensively and dynamically modulated at the level of translation (messenger RNA to protein). Over the recent years, significant progress has been made in dissecting the complex posttranscriptional mechanisms that regulate gene expression. This advancement in knowledge came hand in hand with the progress made in the methodologies to study translation both at gene-specific as well as global genomic level. The majority of translational control is exerted at the level of initiation; nonetheless, protein synthesis can be modulated at the level of translation elongation, termination, and recycling. Sequence and structural elements and epitranscriptomic modifications of individual transcripts allow for dynamic gene-specific modulation of translation. Cancer cells usurp the regulatory mechanisms that govern translation to carry out translational programs that lead to the phenotypic hallmarks of cancer. Translation is a critical nexus in neoplastic transformation. Multiple oncogenes and signaling pathways that are activated, upregulated, or mutated in cancer converge on translation and their transformative impact "bottlenecks" at the level of translation. Moreover, this translational dysregulation allows cancer cells to adapt to a diverse array of stresses associated with a hostile microenviroment and antitumor therapies. All elements involved in the process of translation, from the transcriptional template, the components of the translational machinery, to the proteins that interact with the transcriptome, have been found to be qualitatively and/or quantitatively perturbed in cancer. This review discusses the regulatory mechanisms that govern translation in normal cells and how translation becomes dysregulated in cancer leading to the phenotypic hallmarks of malignancy. We also discuss how dysregulated mediators or components of translation can be utilized as biomarkers with potential diagnostic, prognostic, or predictive significance. Such biomarkers have the potential advantage of uniform applicability in the face of inherent tumor heterogeneity and deoxyribonucleic acid instability. As translation becomes increasingly recognized as a process gone awry in cancer and agents are developed to target it, the utility and significance of these potential biomarkers is expected to increase.

Plasma exosomal miRNAs-based prognosis in metastatic kidney cancer

Plasma exosomal miRNAs were evaluated for prognosis in an initial set of 44 metastatic renal cell cancer (mRCC) patients by RNA sequencing. Among ∼3.49 million mappable reads per patient, miRNAs accounted for 93.1% of the mapped RNAs. 227 miRNAs with high abundance were selected for survival analysis. Cox regression analysis identified association of 6 miRNAs with overall survival (OS) (P<0.01, False discovery rate (FDR) < 0.3). Five of the associated miRNAs were quantified in an independent follow-up cohort of 65 mRCC patients by TaqMan-based miRNA assays. Kaplan-Meier analysis confirmed the significant OS association of three miRs; miR-let-7i-5p (P=0.018, HR=0.49, 95% CI=0.21-0.84), miR-26a-1-3p (P=0.025, HR=0.43, 95% CI=0.10-0.84) and miR-615-3p (P=0.0007, HR=0.36, 95% CI=0.11-0.54). A multivariate analysis of miR-let-7i-5p with the clinical factor-based Memorial Sloan-Kettering Cancer Center (MSKCC) score improved survival prediction from an area under the curve (AUC) of 0.58 for MSKCC score to an average AUC of 0.64 across 48-month follow-up time. The multivariate model was able to define a high-risk group with median survival of 14 months and low risk group of 39 months (P=0.0002, HR=3.43, 95%CI, 2.73-24.15). Further validation of miRNA-based prognostic biomarkers are needed to improve current clinic-pathologic based prognostic models in patients with mRCC.

Systematic review of renal carcinoma prognostic factors

CONTEXT AND OBJECTIVES

The natural history of renal cell carcinoma is heterogeneous. Some scenarios can be found in terms of clinical presentation, clinical evolution or type of recurrence (local/metastatic). The aim of this publication is to analyze the most important prognostic factors published in the literature.

EVIDENCE ACQUISITION

A literature review ob published papers was performed using the Pubmed, from first Motzer's classification published in 1999 to 2015, according to PRISMA declaration. Search was done using the following keywords: kidney neoplasm, kidney cancer, renal cell carcinoma, prognostic factors, mortality, survival and disease progression. Papers were classified according to level of evidence, the number of patients included and the type of study performed.

EVIDENCE SYNTHESIS

The evolution in the knowledge of molecular pathways related to renal oncogenesis and the new targeted therapies has left to remain obsolete the old prognostic models. It's necessary to perform a continuous review to actualize nomograms and to adapt them to the new scenarios.

CONCLUSIONS

Is necessary to perform a proper external validation of existing prognostic factors using prospective and multicentric studies to add them into the daily urologist clinical practice.

Bone Metastasis from Renal Cell Carcinoma

About one-third of patients with advanced renal cell carcinoma (RCC) have bone metastasis that are often osteolytic and cause substantial morbidity, such as pain, pathologic fracture, spinal cord compression and hypercalcemia. The presence of bone metastasis in RCC is also associated with poor prognosis. Bone-targeted treatment using bisphosphonate and denosumab can reduce skeletal complications in RCC, but does not cure the disease or improve survival. Elucidating the molecular mechanisms of tumor-induced changes in the bone microenvironment is needed to develop effective treatment. The “vicious cycle” hypothesis has been used to describe how tumor cells interact with the bone microenvironment to drive bone destruction and tumor growth. Tumor cells secrete factors like parathyroid hormone-related peptide, transforming growth factor-β and vascular endothelial growth factor, which stimulate osteoblasts and increase the production of the receptor activator of nuclear factor κB ligand (RANKL). In turn, the overexpression of RANKL leads to increased osteoclast formation, activation and survival, thereby enhancing bone resorption. This review presents a general survey on bone metastasis in RCC by natural history, interaction among the immune system, bone and tumor, molecular mechanisms, bone turnover markers, therapies and healthcare burden.

MicroRNA-22 is downregulated in clear cell renal cell carcinoma, and inhibits cell growth, migration and invasion by targeting PTEN

MicroRNA (miR)-22 has previously been reported to be frequently downregulated in certain types of cancer. The present study examined the expression and effects of miR-22 in renal cell carcinoma (RCC). The results indicated that miR‑22 was downregulated in tumor tissue from patients with RCC. In addition, lower miR‑22 expression levels were associated with histological grade, tumor stage and lymph node metas-tasis. Following transfection of RCC cells with miR‑22, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, cell migration, cell invasion and luciferase assays, and western blotting were conducted. The results demonstrated that miR‑22 was able to inhibit cell proliferation, migration and invasion in 786‑O and A498 cells. Furthermore, the results indicated that miR‑22 may directly target phosphatase and tensin homolog (PTEN) in RCC. In conclusion, the present study suggested that the miR-22/PTEN axis may be considered a novel therapeutic target in RCC. These findings may be beneficial for the development of an effective therapy against RCC.

EIF3D silencing suppresses renal cell carcinoma tumorigenesis via inducing G2/M arrest through downregulation of Cyclin B1/CDK1 signaling

There are no effective therapies for advanced renal cell carcinoma (RCC), except for VEGFR inhibitors with only ~50% response rate. To identify novel targets and biomarkers for RCC is of great importance in treating RCC. In this study, we observed that eukaryotic initiation factor 3d (EIF3D) expression was significantly increased in RCC compared with paracarcinoma tissue using immunohistochemistry staining and western blot analysis. Furthermore, bioinformatics meta-analysis using ONCOMINE microarray datasets showed that EIF3D mRNA expressions in CCRCC tissue specimens were significantly higher than that in normal tissue specimens. In addition, RCC tissue microarray demonstrated that elevated EIF3D expression was positively correlated with TNM stage and tumor size. EIF3D silencing in human 786-O and ACHN CCRCC cell lines by RNA interference demonstrated that EIF3D knockdown obviously inhibited cell proliferation and colony formation, caused G2/M arrest through downregulation of Cyclin B1 and Cdk1 and upregulation of p21, and induced apoptosis shown by sub-G1 accumulation and RARP cleavage. Moreover, correlation analysis using ONCOMINE microarray datasets indicated that increased EIF3D mRNA expression was positively correlated to PCNA, Cyclin B1 and CDK1 mRNA expression in RCC. Collectively, these results provide reasonable evidences that EIF3D may function as a potential proto-oncogene that participates in the occurrence and progression of RCC.

The RNA binding protein IMP3 facilitates tumor immune escape by downregulating the stress-induced ligands ULPB2 and MICB

Expression of the stress-induced ligands MICA, MICB and ULBP 1–6 are up-regulated as a cellular response to DNA damage, excessive proliferation or viral infection; thereby, they enable recognition and annihilation by immune cells that express the powerful activating receptor NKG2D. This receptor is present not exclusively, but primarily on NK cells. Knowledge about the regulatory mechanisms controlling ULBP expression is still vague. In this study, we report a direct interaction of the oncogenic RNA binding protein (RBP) IMP3 with ULBP2 mRNA, leading to ULBP2 transcript destabilization and reduced ULBP2 surface expression in several human cell lines. We also discovered that IMP3 indirectly targets MICB with a mechanism functionally distinct from that of ULBP2. Importantly, IMP3-mediated regulation of stress-ligands leads to impaired NK cell recognition of transformed cells. Our findings shed new light on the regulation of NKG2D ligands and on the mechanism of action of a powerful oncogenic RBP, IMP3.

DOI:http://dx.doi.org/10.7554/eLife.13426.001

Tumor cells differ from healthy cells in many aspects. Importantly, tumor cells have the ability to divide and grow much faster than normal cells. To protect ourselves from full-grown cancers, our bodies have developed a surveillance system: when a tumor cell starts to divide without restraint, “stress-induced” proteins start to appear on its surface. These proteins help the immune system recognize abnormal or damaged cells, allowing the immune cells to eliminate the defective cells.

Despite this system of protection, a tumor cell sometimes manages to avoid having stress-induced proteins placed on its surface, allowing it to remain undetected by the immune system. By studying several different types of human cancer cells, Schmiedel et al. found that a protein called IMP3 is present in cancer cells but not in healthy cells. Further investigation revealed that IMP3 prevents the production of some stress-induced proteins and stops them moving to the cell surface.

Schmiedel et al. also show that the presence of the IMP3 protein in cancer cells causes nearby immune cells to become much less active. This suggests that developing drugs that block the activity of IMP3 could help the immune system to fight back and destroy cancer cells.

DOI:http://dx.doi.org/10.7554/eLife.13426.002

Increased Insulin mRNA Binding Protein-3 Expression Correlates with Vascular Enhancement of Renal Cell Carcinoma by Intravenous Contrast-CT and is Associated with Bone Metastasis

Purpose

To: 1) assess the correlation between CT vascularity and a candidate molecular marker of RCC metastasis (insulin-like mRNA binding protein-3 (IMP3)); and 2) demonstrate the differential expression of IMP3 in high vs. low vascular tumors.

Experimental design

Retrospectively obtained contrast CT from 72 patients with primary RCC were used to establish threshold values for Low, Intermediate and High tumor vascularity. Paired histopathology specimens from 33 of these patients were used for immunohistochemistry (IHC) to correlate CT with IMP-3 expression. IMP-3 gene expression studies were performed on RCC and poorly vascular prostate cancer (PC) human bone metastases samples to confirm presence of IMP3 in metastatic samples from RCC. Gene expression studies were performed on RCC 786-O and PC3 cell lines to confirm the presence of high expression of IMP3 in the RCC cell line.

Results

IMP-3 expression positively correlated with CT vascular enhancement (p<0.01). IMP3 expression by IHC was strongly positive in all RCC, but weak in PC bone metastases. Real time RT-PCR demonstrated a significant 4-fold increase in imp-3 expression in RCC 786-O vs. PC3 cells in vitro (p<0.001).

Conclusion

Quantitation of pre-operative CT is a feasible method to phenotype primary RCC vascularity, which correlates with IMP-3 expression. In situ and cell line studies demonstrate an association between high IMP-3 expression and RCC bone metastasis. Studies aimed at defining the diagnostic potential of biomarkers for RCC bone metastasis, and functional significance of IMP-3 in RCC vascularity and tumor progression are warranted.

IMP3 expression in serous tumors of the ovary

Insulin-like growth factor II mRNA-binding protein (IMP3) is an oncofetal protein involved in embryogenesis, which is expressed in a variety of malignant neoplasms. It is rarely expressed in normal adult tissue and benign tumors. The aim of this study was to evaluate the expression of IMP3 in benign and malignant serous tumors of the ovary. Seventy-nine ovarian tumors were examined for IMP3 expression by immunohistochemical analysis, comprising 16 benign serous tumors, 19 borderline serous tumors, and 44 serous carcinomas. Positive staining was defined as brown staining in the cytoplasm. Negative staining was defined as absent staining or staining of <5% of tumor cells. The intensity of staining (weak, moderate, and strong) and percentage (0% to 100%) of neoplastic cells staining positive for cytoplasmic IMP3 staining were recorded in each case. Moderate to strong cytoplasmic staining for IMP3 was observed in 30 of 44 (68%) serous carcinomas of the ovary; in contrast, <5% of the borderline and benign serous tumors expressed IMP3 ranging from weak to strong cytoplasmic staining. Statistically, the difference in IMP3 expression between these groups of tumors was highly significant (P<0.0001). Our findings demonstrate moderate to strong expression of IMP3 in the majority of ovarian serous carcinomas as compared with benign/borderline serous tumors, which demonstrated weak to strong expression in a small minority (<5%) of the tumors. Thus, IMP3 may be a useful adjunctive tool in the pathologic evaluation of ovarian serous tumors.

Effects of the novel heat shock protein 90 inhibitor AUY922 in renal cell carcinoma ACHN and 786-O cells

The aim of the present study was to investigate the effects of the heat shock protein (HSP)90 inhibitor AUY922 on the proliferation and migratory ability of renal cell carcinoma (RCC) cells. The expression of HSP90 was measured in vitro using western blotting and quantitative polymerase chain reaction in the ACHN and 786-O cell RCC lines, and also in the immortalized normal human proximal tubule epithelium HK-2 cell line. The effects of the time and concentration of AUY922 administration were investigated in the ACHN and 786-O cells, and the cell proliferation was measured using an MTT assay. A Transwell assay was performed to evaluate the migratory ability of ACHN cells following treatment with AUY922 at concentrations of 10, 50 and 100 nM. Western blot analysis and reverse transcription polymerase chain reaction revealed that HSP90 mRNA and protein were overexpressed in the two RCC cell lines compared with the HK-2 cell line. AUY922 inhibited the proliferation of the ACHN and 786-O cells in a time- and concentration-dependent manner, and the migratory ability of the ACHN cells was markedly suppressed subsequent to treatment with AUY922. The present data suggest that the pathogenesis of human RCC may be mediated by HSP90. It was also indicated that the specific HSP90 inhibitor AUY922 plays a therapeutic role in the treatment of RCC, and therefore, HSP90 may be a selective target for molecular-targeted treatments of RCC.

Enhanced IMP3 Expression Activates NF-кB Pathway and Promotes Renal Cell Carcinoma Progression

BACKGROUND

Insulin-like growth factor 2 mRNA binding protein 3 (IMP3) is expressed in metastatic and a subset of primary renal cell carcinoma (RCC). However, the role of IMP3 in RCC progression was poorly understood. We aim to uncover the mechanism of IMP3 in regulating clear cell RCC (CCRCC) progression and validate the prognostic significance of IMP3 in localized CCRCC.

METHODS

Caki-1 cells stably overexpressing IMP3 and Achn cells with knockdown of IMP3 were analyzed for cell migration and invasion by Transwell assay. RNA-seq was used to profile gene expression in IMP3-expressing Caki-1 cells. A cohort of 469 localized CCRCC patients were examined for IMP3 expression by immunohistochemistry using tumor tissue array.

RESULTS

IMP3 promoted Caki-1 cell migration and invasion, whereas knockdown of IMP3 by RNAi inhibited Achn cell migration and invasion. Enhanced IMP3 expression activated NF-кB pathway and through which, it functioned in promoting the RCC cell migration. IMP3 expression in localized CCRCC was found to be associated with higher nuclear grade, higher T stage, necrosis and sarcomatoid differentiation (p< 0.001). Enhanced IMP3 expression was correlated with shorter recurrence-free and overall survivals. Multivariable analysis validated IMP3 as an independent prognostic factor for localized CCRCC patients.

CONCLUSION

IMP3 promotes RCC cell migration and invasion by activation of NF-кB pathway. IMP3 is validated to be an independent prognostic marker for localized CCRCC.

MiR-506 is down-regulated in clear cell renal cell carcinoma and inhibits cell growth and metastasis via targeting FLOT1

Background

Some microRNAs (miRNAs) are abnormally expressed in cancer and contribute to tumorigenesis. In the present study, we investigated the role of miR-506 in clear cell renal cell carcinoma (ccRCC).

Methods

miR-506 expression was detected in renal cancer cell lines 786-O, ACHN, Caki-1, and Caki-2 and ccRCC specimens by quantitative real-time-PCR. We assessed the association of miR-506 expression with pathology and prognosis in ccRCC patients. We over-expressed and knocked-down miR-506 expression in two renal cancer cell lines, 786-O and ACHN, and assessed the impact on cell proliferation, migration and invasion. A luciferase reporter assay was conducted to confirm the target gene of miR-506 in renal cancer cell lines.

Results

miR-506 was significantly down-regulated in renal cancer cell lines and ccRCC specimens. Low miR-506 expression in ccRCC specimens was associated with an advanced clinical stage and poor prognosis. miR-506 expression was an independent prognostic marker of overall ccRCC patient survival in a multivariate analysis. Over-expression of miR-506 in renal cancer cells decreased cell growth and metastasis, In contrast, down-regulation of miR-506 expression promoted renal cancer cell growth and metastasis. FLOT1, a potential target gene of miR-506, was inversely correlated with miR-506 expression in ccRCC tissues. Consistent with the effect of miR-506, knockdown of FLOT1 by siRNA inhibited cell malignant behaviors. Rescue of FLOT1 expression partially restored the effects of miR-506.

Conclusions

miR-506 exerts its anti-cancer function by directly targeting FLOT1 in renal cancer, indicating a potential novel therapeutic role in renal cancer treatment.

Downregulation of tNASP inhibits proliferation through regulating cell cycle-related proteins and inactive ERK/MAPK signal pathway in renal cell carcinoma cells

Nuclear auto-antigenic sperm protein (NASP), initially described as a highly auto-immunogenic testis and sperm-specific protein, is a histone chaperone that is proved to present in all dividing cells. NASP has two splice variants: testicular NASP (tNASP) and somatic form of NASP (sNASP). Only cancer, germ, transformed, and embryonic cells have a high level of expression of the tNASP. Up to now, little has been known about tNASP in renal cell carcinoma (RCC). In the present study, the molecular mechanism of tNASP in RCC was explored. The expression level of tNASP in 16 paired human RCC specimens was determined. Downregulation of tNASP by small interfering RNA (siRNA) was transfected in RCC cell lines. The effect of downregulation of tNASP by siRNA on cell colony formation and proliferation was examined by colony formation assay and CCK-8 assay, cell cycle was analyzed by flow cytometry, and the expression of cyclin D1 and P21 were detected by Western blotting. ERK/MAPK signaling was also analyzed. tNASP has a relative high expression level in human RCC tissues. Via upregulation of P21 and downregulation of cyclinD1, silence of tNASP can inhibit cell proliferation, which induces cell cycle arrest. Furthermore, ERK signaling pathway is confirmed to mediate the regulation of cell cycle-related proteins caused by silence of tNASP. Our research demonstrates that knockdown of tNASP effectively inhibits the proliferation and causes G1 phase arrest through ERK/MAPK signal pathway.

Clinical implications of insulin-like growth factor II mRNA-binding protein 3 expression in non-small cell lung carcinoma

In order to examine the role of insulin-like growth factor II mRNA-binding protein 3 (IMP3) expression for the prognostic evaluation of non-small cell lung carcinoma (NSCLC), a total of 186 breast cancer patients, with adjacent non-tumor lung tissues, were selected for immunohistochemical staining of IMP3 protein. The NSCLC tissues and paired adjacent non-tumor tissues of six patients were quantified using reverse transcription quantitative polymerase chain reaction. The correlations between IMP3 overexpression and the clinical features of NSCLC were evaluated using the χ² test and Fisher’s exact test. The survival rate was calculated using the Kaplan-Meier method, and the association between prognostic factors and patient survival was also analyzed by Cox’s proportional hazards models. The results showed that IMP3 protein exhibited a mainly cytoplasmic staining pattern in the NSCLC tissues. The positive rate of IMP3 protein expression was 74.7% (139/186) in the NSCLC tissues and was significantly higher than the rate of 19.9% (37/186) in the adjacent non-tumor tissues. The expression rate of the NQO1 protein was correlated with a large tumor size, poor differentiation, lymph node metastasis, late clinical stage, and disease-free and overall survival rates in the NSCLC patients. In the early- and late-stage NSCLC groups, the disease-free and overall survival rates of the patients with IMP3 expression were significantly lower than those of the patients without IMP3 expression. Further analysis using Cox’s proportional hazard regression model revealed that IMP3 expression was a significant independent hazard factor for the overall survival rate of patients with NSCLC. In conclusion, the present study found that IMP3 plays a significant role in the progression of NSCLC, and that it may potentially be used as an independent biomarker for prognostic evaluation of the cancer.

Tempo and mode of gene duplication in mammalian ribosomal protein evolution

Gene duplication has been widely recognized as a major driver of evolutionary change and organismal complexity through the generation of multi-gene families. Therefore, understanding the forces that govern the evolution of gene families through the retention or loss of duplicated genes is fundamentally important in our efforts to study genome evolution. Previous work from our lab has shown that ribosomal protein (RP) genes constitute one of the largest classes of conserved duplicated genes in mammals. This result was surprising due to the fact that ribosomal protein genes evolve slowly and transcript levels are very tightly regulated. In our present study, we identified and characterized all RP duplicates in eight mammalian genomes in order to investigate the tempo and mode of ribosomal protein family evolution. We show that a sizable number of duplicates are transcriptionally active and are very highly conserved. Furthermore, we conclude that existing gene duplication models do not readily account for the preservation of a very large number of intact retroduplicated ribosomal protein (RT-RP) genes observed in mammalian genomes. We suggest that selection against dominant-negative mutations may underlie the unexpected retention and conservation of duplicated RP genes, and may shape the fate of newly duplicated genes, regardless of duplication mechanism.

IMP3 expression in gastric cancer: association with clinicopathological features and HER2 status

BACKGROUND

The aim of this study was to evaluate the expression of IMP3, an independent poor prognostic factor for many cancers, and its association with clinicopathological features and HER2 status.

METHODS

Gastrectomy specimens from 106 patients were evaluated by immunohistochemistry and fluorescence in situ hybridization.

RESULTS

HER2 overexpression was found in 4.71 % of the samples. A negative association was observed between HER2 overexpression and grade of differentiation. No association was observed between HER2 overexpression and status of surgical margins, vascular invasion, perineural invasion, nodal metastasis and depth of invasion. Among all specimens of gastric cancer, 67.92 % were positive for IMP3. Expression of IMP3 was significantly higher in specimens with vascular invasion, perineural invasion, nodal metastasis and higher depth of invasion. HER2 overexpression was detected in only 5.55 % of IMP3 positive specimens.

CONCLUSIONS

IMP3 expression was frequently observed in gastric cancer and was associated with poor prognostic clinicopathological features. A survival benefit with HER2 therapy should be expected for the minority of patients with IMP3 positive specimens. Studies should be conducted to evaluate the response to HER2 therapy of gastric cancer expressing IMP3.

The role of the oncofetal IGF2 mRNA-binding protein 3 (IGF2BP3) in cancer

The post-transcriptional control of gene expression mediated by RNA-binding proteins (RBPs), long non-coding RNAs (lncRNAs) as well as miRNAs is essential to determine tumor cell fate and thus is a major determinant in cancerogenesis. The IGF2 mRNA binding protein family (IGF2BPs) comprises three RBPs. Two members of the family, IGF2BP1 and IGF2BP3, are bona fide oncofetal proteins, which are de novo synthesized in various human cancers. In vitro studies revealed that IGF2BPs serve as post-transcriptional fine-tuners modulating the expression of genes implicated in the control of tumor cell proliferation, survival, chemo-resistance and metastasis. Consistently, the expression of both IGF2BP family members was reported to correlate with an overall poor prognosis and metastasis in various human cancers. Due to the fact that most reports used a pan-IGF2BP antibody for studying IGF2BP expression in cancer, paralogue-specific functions can barely be evaluated at present. Nonetheless, the accordance of IGF2BPs' role in promoting an aggressive phenotype of tumor-derived cells in vitro and their upregulated expression in aggressive malignancies provides strong evidence that IGF2BPs are powerful post-transcriptional oncogenes enhancing tumor growth, drug-resistance and metastasis. This suggests IGF2BPs as powerful biomarkers and candidate targets for cancer therapy.

IMP3 signatures of fallopian tube: a risk for pelvic serous cancers

Background

Recent advances suggest fallopian tube as the main cellular source for women’s pelvic serous carcinoma (PSC). In addition to TP53 mutations, many other genetic changes are involved in pelvic serous carcinogenesis. IMP3 is an oncofetal protein which has recently been observed to be overexpressed in benign-looking tubal epithelia. Such findings prompted us to examine the relationship between IMP3 over-expression, patient age and the likelihood of development of PSC.

Methods

Fallopian tubes from three groups (low-risk, high-risk, and PSC) of patients with matched ages were studied. Age was recorded in 10 years intervals ranging from age 20 to older than 80. The number of IMP3 signatures (defined by 10 or more tubal secretory cells stained positively and continuously in benign appearing tubal mucosa) from both tubal fimbria and ampulla segments was measured. The data was analyzed by standard contingency table and Poisson distribution methods after age adjustment. IMP3 overexpression was also examined in serous tubal intraepithelial carcinoma and PSC.

Results

The positive IMP3-stained cells are mainly tubal secretory cells. The absolute number of tubal IMP3 signatures increased significantly within each age group. Age remained a significant risk factor for serous neoplasia after age adjustment. IMP3 signatures were more frequent in the patients of both high-risk and PSC groups. The presence of IMP3 signatures in tubal mucosa was significantly associated with tubal or pelvic serous carcinogenesis (p < 0.001).

Conclusions

The findings suggest that tubal secretory cells with IMP3 signatures showing growth advantage could potentially serve as a latent precancer biomarker for tubal or pelvic serous carcinomas in women.

Overexpression of SATB1 is associated with biologic behavior in human renal cell carcinoma

Special AT-rich sequence-binding protein-1 (SATB1) has been reported to be aberrantly expressed in various cancers and correlated with the malignant behavior of cancer cells. However, the function of SATB1 in RCC remains unclear. With the combination of immunohistochemistry, western blotting, immunofluorescence, qRT-PCR, and cell proliferation, migration and invasion assays, we found that levels of SATB1 mRNA and protein were dramatically increased in human ccRCC tissues (P<0.001 for both), and upregulation of SATB1 was significantly associated with depth of invasion (P<0.001), lymph node status (P = 0.001) and TNM stage (P = 0.009). SATB1 knockdown inhibited the proliferation, migration and invasion of 786-O cells, whereas SATB1 overexpression promoted the growth and aggressive phenotype of ACHN cells in vitro. Furthermore, SATB1 expression was positively correlated with ZEB2 expression (P = 0.013), and inversely linked to levels of SATB2 and E-cadherin (P = 0.005 and P<0.001, respectively) in ccRCC tissues. Our data provide a basis for the concept that overexpression of SATB1 may play a critical role in the acquisition of an aggressive phenotype for RCC cells through EMT, providing new insights into the significance of SATB1 in invasion and metastasis of ccRCC, which may contribute to fully elucidating the exact mechanism of development and progression of RCC.

Decreased expression of NPRL2 in renal cancer cells is associated with unfavourable pathological, proliferation and apoptotic features

The tumor suppressor gene nitrogen permease regulator-like 2(NPRL2) NPRL2 expressed obviously in many normal human tissues, but reduced in expression in many human tumors significantly. In this study, we detected the expression of NPRL2 in 78 clear cell renal cell carcinoma (ccRCC) by immunohistochemistry and correlated it with clinicopathological parameters. Meanwhile, the function of NPRL2 in human ccRCC was further explored after transfected recombinant expressing plasmids pEGFP-N1-NPRL2 into human renal cancer 786-0 cells. NPRL2 protein showed high expression in 67 of 78 cases of adjacent normal tissues (85.9 %), which was significantly higher than that in ccRCC tissues (23/78, 29.5 %). Clinic pathological analysis showed that NPRL2 expression was significantly correlated with histological grade (P = 0.044), TNM stage (P = 0.025) and lymph node metastasis (P = 0.028). MTT assay demonstrated that NPRL2 could obviously inhibit renal cancer cell proliferation. Flow cytometric analysis revealed that NPRL2 could induce renal cancer cells apoptosis and arrest the cell cycle in G0/G1 phase. In conclusion, NPRL2 is closely correlated to unfavourable pathological, proliferation and apoptotic features in ccRCC.

IMP3, a Promising Prognostic Marker in Clear Cell Renal Cell Carcinoma

Background

Insulin-like growth factor II mRNA-binding protein 3 (IMP3) has been reported as a prognostic biomarker in various cancers. To validate IMP3 as a prognostic biomarker in renal cell carcinoma (RCC), we investigated the expression of IMP3, p53, and Ki-67, and their associations with clinicopathologic outcomes.

Methods

We studied 148 clear cell RCCs (CCRCCs) from patients who underwent radical nephrectomy. The expression levels of IMP3, p53, and Ki-67 were assessed by immunohistochemical staining and the clinical and pathologic parameters were retrospectively reviewed.

Results

Twenty-nine percent of CCRCCs expressed IMP3. Forty-one percent of IMP3-immunopositive tumors developed metastases, while only 11.4% of IMP3-negative tumors developed metastases (p<.001). A Kaplan-Meier curve showed that patients with IMP3-immunopositive tumors had lower metastasis-free survival and cancer-specific survival than did those with IMP3-immunonegative tumors (p<.001 and p<.001, respectively). Expression of high Ki-67 proliferation index was also associated with a higher metastatic rate. In the multivariate Cox regression analysis, pT stage and IMP3-positivity were independently associated with disease-specific survival.

Conclusions

IMP3 is an independent prognostic biomarker for patients with CCRCC to predict metastasis and poor outcome.

IMP3 RNP safe houses prevent miRNA-directed HMGA2 mRNA decay in cancer and development

The IMP3 RNA-binding protein is associated with metastasis and poor outcome in human cancer. Using solid cancer transcriptome data, we found that IMP3 correlates with HMGA2 mRNA expression. Cytoplasmic IMP3 granules contain HMGA2, and IMP3 dose-dependently increases HMGA2 mRNA. HMGA2 is regulated by let-7, and let-7 antagomiRs make HMGA2 refractory to IMP3. Removal of let-7 target sites eliminates IMP3-dependent stabilization, and IMP3-containing bodies are depleted of Ago1-4 and miRNAs. The relationship between Hmga2 mRNA and IMPs also exists in the developing limb bud, where IMP1-deficient embryos show dose-dependent Hmga2 mRNA downregulation. Finally, IMP3 ribonucleoproteins (RNPs) contain other let-7 target mRNAs, including LIN28B, and a global gene set enrichment analysis demonstrates that miRNA-regulated transcripts in general are upregulated following IMP3 induction. We conclude that IMP3 RNPs may function as cytoplasmic safe houses and prevent miRNA-directed mRNA decay of oncogenes during tumor progression.

GOLPH3 is a novel marker of poor prognosis and a potential therapeutic target in human renal cell carcinoma

Background:

Golgi phosphoprotein 3 (GOLPH3) has been reported to be involved in the development of several human cancers. The present study was conducted to investigate the expression of GOLPH3 and its prognostic significance in renal cell carcinoma (RCC). Meanwhile, the function of GOLPH3 in human RCC was further investigated in cell culture models.

Methods:

Expression of GOLPH3 was examined in 43 fresh RCC tissues and paired adjacent normal renal tissues by real-time quantitative PCR and western blotting. Immunohistochemistry for GOLPH3 was performed on additional 218 RCC tissues. The clinical significance of GOLPH3 expression was analysed. Downregulation of GOLPH3 was performed using small-interfering RNA (siRNA) in Caki-1 and 786-O cells with high abundance of GOLPH3, and the effects of GOLPH3 silencing on cell proliferation, migration, invasion in vitro, and tumour growth in vivo were evaluated.

Results:

Expression of GOLPH3 was upregulated in the majority of the RCC clinical tissue specimens at both mRNA and protein levels. Clinicopathological analysis showed that GOLPH3 expression was significantly correlated with T stage (P<0.001), lymph-node status (P=0.003), distant metastasis (P<0.001), tumour-node-metastasis (TNM) stage (P<0.001), and Fuhman grade (P=0.001). Expression of GOLPH3 was inversely correlated with both overall and recurrence-free survival of RCC patients. Multivariate analysis showed that GOLPH3 expression was an independent prognostic indicator for patient's survival. Knockdown of the GOLPH3 expression reduced cell proliferation, anchorage-independent growth, migration, invasion, and tumour growth in xenograft model mice.

Conclusions:

These results suggest that GOLPH3 expression is likely to have important roles in RCC development and progression, and that GOLPH3 is a prognostic biomarker and a promising therapeutic target for RCC.

IMP3 expression is associated with poor outcome and epigenetic deregulation in intrahepatic cholangiocarcinoma

IMP3 is a fetal protein not expressed in normal adult tissues. IMP3 is an oncoprotein and a useful biomarker for a variety of malignancies and is associated with reduced overall survival of a number of them. IMP3 expression and its prognostic value for patients with intrahepatic cholangiocarcinoma (ICC) have not been well investigated. The molecular mechanism underlying IMP3 expression in human cancer cells remains to be elucidated. Here we investigated IMP3 expression in ICC and adjacent nonneoplastic liver in 72 unifocal primary ICCs from a single institute by immunohistochemistry, immunoblotting, and real-time polymerase chain reaction. IMP3 was specifically expressed in cancer cells but not in the surrounding normal tissue, and 59 (82%) of 72 ICCs were IMP3 positive by immunohistochemistry. Among 35 cases with lymphovascular invasion, 26 (74%) showed IMP3 positivity in lymph node metastases. IMP3 expression was significantly correlated with tumor size, pathological grade, metastasis, and clinical stage. Kaplan-Meier analysis demonstrated an inverse correlation between IMP3 expression and overall survival rate. Multivariate analysis revealed that IMP3 was the only risk factor associated with survival. To further explore the mechanism of IMP3 expression in cancers, we identified 2 CpG islands at IMP3 proximal promoter. Interestingly, the IMP3 promoter was almost completely demethylated in ICCs in contrast to densely methylated promoter in normal liver tissues. IMP3 expression is a useful biomarker for ICCs and can provide an independent prognostic value for patients with ICC. To our knoweldge, this is the first direct evidence of epigenetic deregulation of IMP3 in human cancer.

Clinical implications of current developments in genitourinary pathology

CONTEXT

Several developments in genitourinary pathology are likely to change our understanding and management of some genitourinary cancers considerably.

OBJECTIVE

To review 5 stories in genitourinary pathology: (1) fusion in the ETS (E26) gene family in prostatic adenocarcinoma; (2) insulin-like growth factor II messenger RNA-binding protein 3 (IMP3), an important prognostic biomarker for kidney and bladder cancers; (3) translocation renal cell carcinoma; (4) UroVysion fluorescence in situ hybridization test in urine cytology for detection of bladder cancer; and (5) the use of triple immunostaining for diagnosis of prostate cancer.

DATA SOURCES

Literature review and authors' personal experiences.

CONCLUSIONS

Many scientific findings have contributed recently to the understanding of the natural pathogenesis and progression of genitourinary cancers. This translational research helps in diagnosing, predicting, and potentially, treating genitourinary cancers.

Insulin-like growth factor-II mRNA-binding protein 3 predicts a poor prognosis for colorectal adenocarcinoma

Insulin-like growth factor-II mRNA-binding protein 3 (IMP3) has been recently identified as a marker of aggressive behavior in several types of tumors. The aim of the present study was to detect the expression of the IMP3 protein in colorectal adenocarcinoma (CRA) and to identify a correlation with the clinicopathological features of the disease. IMP3 was evaluated in 186 samples of CRA using immunohistochemical methods. The correlation between IMP3 expression and the clinicopathological features of colorectal cancer was evaluated by the χ² and Fisher’s exact tests. Survival rates were calculated using the Kaplan-Meier method and the correlation between IMP3 protein expression and the prognosis of patients with CRA was analyzed using Cox analysis. Of the 186 adjacent normal mucosa (ANM) cases, the 22 that exhibited dysplasia demonstrated weak IMP3 expression and the 164 without dysplasia showed no expression. Of the 186 CRA cases, immunohistochemical staining for IMP3 was observed in 143 cases (76.9%). A comparison of IMP3 expression between the CRA and ANM samples revealed stronger immunohistochemical reactivity in the CRA tissues (P<0.01). High IMP3 expression was associated with differentiation, lymphoid metastasis, TNM stage, Ki-67 labeling index and a poor patient outcome (P<0.05). In the multivariate analysis, IMP3 emerged as an independent predictor of survival. The present study demonstrated that IMP3 is able to promote the aggressiveness of cancer behavior, resulting in a poor prognosis for patients with CRA. Consequently, IMP3 may be regarded as a novel proliferation and prognostic indicator for patients with CRA.

Oncofetal protein IMP3: a new diagnostic biomarker for laryngeal carcinoma

An accurate diagnosis of laryngeal squamous cell carcinoma (LSCC) is essential for patient management. The diagnosis of LSCC, especially in superficial biopsies, can present a diagnostic challenge for pathologists. The ability to diagnose LSCC would be greatly improved by the detection of a tumor-associated antigen. IMP3 is an oncofetal protein associated with aggressive and advanced tumors and is specifically expressed in malignant tumors but not found in benign tissues. The aim of this study was to determine the expression and diagnostic value of IMP3 in LSCC to determine whether it can serve as a diagnostic biomarker. A total of 238 cases (laryngectomy, n = 121; biopsy, n = 117) consisting of 11 laryngeal carcinoma in situ/severe dysplasia and 227 invasive LSCC were examined by immunohistochemistry for IMP3 expression. IMP3 showed strong cytoplasmic staining in 217 (92%) of 238 LSCCs regardless of histologic grade. In addition, 58 (89%) of 65 small biopsies (≤5 mm in greatest dimension) containing a minute amount of carcinoma were positive for IMP3. In contrast to malignant tumors, IMP3 expression was not found in any of the adjacent benign squamous epithelium (0/118 cases; 0%), mild or moderate dysplasia (0/139 cases; 0%), or pseudoepitheliomatous hyperplasia (0/99 cases; 0%). In summary, we are the first to describe that IMP3 is a highly sensitive and specific biomarker for LSCC. The expression of IMP3 in LSCC can be used as a positive biomarker to increase the level of confidence in establishing a definitive diagnosis of a malignancy in laryngeal biopsy.

Insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs): post-transcriptional drivers of cancer progression?

The insulin-like growth factor-2 mRNA-binding proteins 1, 2, and 3 (IGF2BP1, IGF2BP2, IGF2BP3) belong to a conserved family of RNA-binding, oncofetal proteins. Several studies have shown that these proteins act in various important aspects of cell function, such as cell polarization, migration, morphology, metabolism, proliferation and differentiation. In this review, we discuss the IGF2BP family’s role in cancer biology and how this correlates with their proposed functions during embryogenesis. IGF2BPs are mainly expressed in the embryo, in contrast with comparatively lower or negotiable levels in adult tissues. IGF2BP1 and IGF2BP3 have been found to be re-expressed in several aggressive cancer types. Control of IGF2BPs’ expression is not well understood; however, let-7 microRNAs, β-catenin (CTNNB1) and MYC have been proposed to be involved in their regulation. In contrast to many other RNA-binding proteins, IGF2BPs are almost exclusively observed in the cytoplasm where they associate with target mRNAs in cytoplasmic ribonucleoprotein complexes (mRNPs). During development, IGF2BPs are required for proper nerve cell migration and morphological development, presumably involving the control of cytoskeletal remodeling and dynamics, respectively. Likewise, IGF2BPs modulate cell polarization, adhesion and migration in tumor-derived cells. Moreover, they are highly associated with cancer metastasis and the expression of oncogenic factors (KRAS, MYC and MDR1). However, a pro-metastatic role of IGF2BPs remains controversial due to the lack of ‘classical’ in vivo studies. Nonetheless, IGF2BPs could provide valuable targets in cancer treatment with many of their in vivo roles to be fully elucidated.

"Orphan" retrogenes in the human genome

Gene duplicates generated via retroposition were long thought to be pseudogenized and consequently decayed. However, a significant number of these genes escaped their evolutionary destiny and evolved into functional genes. Despite multiple studies, the number of functional retrogenes in human and other genomes remains unclear. We performed a comparative analysis of human, chicken, and worm genomes to identify “orphan” retrogenes, that is, retrogenes that have replaced their progenitors. We located 25 such candidates in the human genome. All of these genes were previously known, and the majority has been intensively studied. Despite this, they have never been recognized as retrogenes. Analysis revealed that the phenomenon of replacing parental genes with their retrocopies has been taking place over the entire span of animal evolution. This process was often species specific and contributed to interspecies differences. Surprisingly, these retrogenes, which should evolve in a more relaxed mode, are subject to a very strong purifying selection, which is, on average, two and a half times stronger than other human genes. Also, for retrogenes, they do not show a typical overall tendency for a testis-specific expression. Notably, seven of them are associated with human diseases. Recognizing them as “orphan” retrocopies, which have different regulatory machinery than their parents, is important for any disease studies in model organisms, especially when discoveries made in one species are transferred to humans.

Overexpression of FoxM1 is associated with tumor progression in patients with clear cell renal cell carcinoma

Background

Fork head box M1 (FoxM1) is a proliferation-associated transcription factor essential for cell cycle progression. Numerous studies have documented that FoxM1 has multiple functions in tumorigenesis and its elevated levels are frequently associated with cancer progression. The present study was conducted to investigate the expression of FoxM1 and its prognostic significance in clear cell renal cell carcinoma (ccRCC). Meanwhile, the function of FoxM1 in human ccRCC was further investigated in cell culture models.

Methods

Real-time quantitative PCR, western blot and immunohistochemistry were used to explore FoxM1 expression in ccRCC cell lines and primary ccRCC clinical specimens. FoxM1 expression was knocked down by small interfering RNA (siRNA) in Caki-1 and 786-O cells; proliferation, colony formation, cell cycle, migration, invasion, and angiogenesis were assayed.

Results

FoxM1 expression was up-regulated in the majority of the ccRCC clinical tissue specimens at both mRNA and protein levels. Clinic pathological analysis showed that FoxM1 expression was significantly correlated with primary tumor stage (P <0.001), lymph node metastasis (P = 0.01), distant metastasis (P = 0.01), TNM stage (P < 0.001) and histological grade (P = 0.003). The Kaplan–Meier survival curves revealed that high FoxM1 expression was associated with poor prognosis in ccRCC patients (P < 0.001). FoxM1 expression was an independent prognostic marker of overall ccRCC patient survival in a multivariate analysis (P = 0.008). Experimentally, we found that down-regulation of FoxM1 inhibited cell proliferation and induced cell cycle arrest with reduced expression of cyclin B1, cyclin D1, and Cdk2, and increased expression of p21 and p27. Also, down-regulation of FoxM1 reduced expression and activity of matrix metalloproteinase-2 (MMP-2), MMP-9 and vascular endothelial growth factor (VEGF), resulting in the inhibition of migration, invasion, and angiogenesis.

Conclusions

These results suggest that FoxM1 expression is likely to play important roles in ccRCC development and progression, and that FoxM1 is a prognostic biomarker and a promising therapeutic target for ccRCC.

Oncofetal protein IMP3: a useful diagnostic biomarker for leiomyosarcoma

An accurate diagnosis between leiomyoma and leiomyosarcoma is essential for patient management. IMP3 is a member of the insulin-like growth factor (IGF-II) mRNA binding protein (IMP) family that consist of IMP1, IMP2, and IMP3. IMP3 is an oncofetal protein associated with aggressive and advanced tumors and is specifically expressed in malignant tumors but not found in benign tissues. The aim of this study was to determine the expression and diagnostic value of IMP3 in leiomyoma and leiomyosarcoma. A total of 216 cases (resection, n = 183; biopsy, n = 33) consisting of 82 leiomyosarcomas (uterine, n = 15; soft tissue, n = 67), 62 leiomyomas (uterine, n = 50; soft tissue, n = 12), and 72 uterine-variant leiomyomas (atypical, n = 19 [14%]; cellular, n = 21 [16%]; mitotically active, n = 12 [9%]; myxoid, n = 11 [8%]; vascular, n = 3 [2%]; epithelioid, n = 1 [1%]; benign metastasizing, n = 1 [1%]; and smooth muscle tumors of uncertain malignant potential, n = 4) were examined by immunohistochemistry for IMP3 expression. IMP3 showed strong cytoplasmic staining in 43 (52%) of 82 leiomyosarcomas, regardless of histologic grades. There was no difference in IMP3 expression between uterine and soft tissue leiomyosarcomas. In contrast to malignant tumors, IMP3 expression was not found in any of the typical leiomyomas (0/62 cases). All uterine-variant leiomyomas were negative, except for 3 cases (atypical variant, n = 2; cellular variant, n = 1) for IMP3 staining. In summary, we are the first to describe IMP3 expression in smooth muscle tumors. Our findings indicate that the expression of IMP3 in both uterine and soft tissue leiomyosarcomas can be used as a positive biomarker to increase the level of confidence in establishing a definitive diagnosis of a malignant smooth muscle tumor.