Distinctive expression patterns of glycoprotein non‐metastatic B and folliculin in renal tumors in patients with Birt–Hogg–Dubé syndrome

Birt–Hogg–Dubé syndrome (BHD) is an inherited disorder associated with a germline mutation of the folliculin gene (FLCN). The affected families have a high risk for developing multiple renal cell carcinomas (RCC). Diagnostic markers that distinguish between FLCN‐related RCC and sporadic RCC have not been investigated, and many patients with undiagnosed BHD fail to receive proper medical care. We investigated the histopathology of 27 RCCs obtained from 18 BHD patients who were diagnosed by genetic testing. Possible somatic mutations of RCC lesions were investigated by DNA sequencing. Western blotting and immunohistochemical staining were used to compare the expression levels of FLCN and glycoprotein non‐metastatic B (GPNMB) between FLCN‐related RCCs and sporadic renal tumors (n = 62). The expression of GPNMB was also evaluated by quantitative RT‐PCR. Histopathological analysis revealed that the most frequent histological type was chromophobe RCC (n = 12), followed by hybrid oncocytic/chromophobe tumor (n = 6). Somatic mutation analysis revealed small intragenic mutations in six cases and loss of heterozygosity in two cases. Western blot and immunostaining analyses revealed that FLCN‐related RCCs showed overexpression of GPNMB and underexpression of FLCN, whereas sporadic tumors showed inverted patterns. GPNMB mRNA in FLCN‐related RCCs was 23‐fold more abundant than in sporadic tumors. The distinctive expression patterns of GPNMB and FLCN might identify patients with RCCs who need further work‐up for BHD.     

Claspin overexpression is associated with high‐grade histology and poor prognosis in renal cell carcinoma

Renal cell carcinoma (RCC) is one of the most common human cancers. We previously reported that claspin is a key regulator in the progression of gastric cancer, and it likely plays an important role in cancer stem cells of gastric cancer. However, the significance of claspin in RCC has not been examined. First, we analyzed the expression and distribution of claspin in 95 RCC cases by immunohistochemistry. In the nonneoplastic kidney, the staining of claspin was either weak or absent, whereas RCC tissue showed nuclear staining. In total, claspin expression was detected in 45 (47%) of 95 RCC cases. The claspin staining appeared relatively stronger in high nuclear grade RCC than in low nuclear grade RCC. Claspin‐positive RCC cases were associated with higher T grade, tumor stage, nuclear grade, vein invasion, and poorer prognosis. CLSPN siRNA treatment decreased RCC cell proliferation. The levels of phosphorylated Erk and Akt were lower in CLSPN siRNA‐transfected RCC cells than in control cells. In addition, claspin was coexpressed with CD44, epidermal growth factor receptor, p53, and programmed death ligand‐1. These results suggest that claspin plays an important role in tumor progression in RCC and might be a prognostic marker and novel therapeutic target molecule.     

Chromosome 9p deletions identify an aggressive phenotype of clear cell renal cell carcinoma

BACKGROUND:

The authors investigated whether deletion of chromosome 9p in clear cell renal cell carcinoma (ccRCC) predicted worse disease‐specific survival (DSS) and recurrence‐free survival (RFS) and whether it was associated with more aggressive behavior in small renal masses.

METHODS:

In total, 703 ccRCC tumors were analyzed using fluorescence in situ hybridization (316 tumors) and cytogenetics (388 tumors). Tumor grade, classification, and size; 9p status; Eastern Cooperative Oncology Group performance status (ECOG PS); lymph node involvement; and the presence of metastasis were recorded. Outcomes were stratified by 9p status, and a Cox proportional hazards models was constructed using TNM staging, ECOG PS, tumor size, tumor grade, and 9p status.

RESULTS:

Deletions of 9p were detected in 97 tumors (13.8%). At presentation, 9p‐deleted tumors were larger and were more likely to be high grade (grade 3 or 4), to have a high tumor (T) classification (T3‐T4), and to have lymph node or distant metastases (P < .01). The median DSS for patients with and without 9p deletions was 37 months and 82 months, respectively (P < .01). In patients with localized disease, the median RFS in those who had 9p deletions was 53 months and was not reached in those without 9p deletions (P < .01). In patients who had localized lesions that measured ≤4 cm in greatest dimension, 9p‐deleted tumors were more likely to recur (19% vs 2%; P = .01).

CONCLUSIONS:

Deletion of chromosome 9p in ccRCC occurred in 14% of patients and was associated with higher grade and T classification, and the presence of lymph node and distant metastases. In addition, 9p deletion independently conferred a worse prognosis for patients with localized ccRCC, and most noteworthy, in patients with localized, small renal masses. Preoperatively identifying patients with 9p deletions will improve risk stratification and will help to select appropriate patients for surveillance protocols or aggressive treatment. Cancer 2010. © 2010 American Cancer Society.     

Lack of mutation of the folliculin gene in sporadic chromophobe renal cell carcinoma and renal oncocytoma

Germline mutation of the folliculin gene (BHD) at chromosome 17p11.2 is associated with the development of multiplex hamartomas of the hair follicles, chromophobe renal cell carcinomas (RCC) and renal oncocytomas (RO). We have analyzed the folliculin gene with sequencing for mutations and the chromosome 17p11.2 with microsatellites for allelic changes in sporadic ROs and chromophobe RCCs. Allelic loss at chromosome 17 was seen in 8 of 8 chromophobe RCCs whereas none of the 8 RO showed alteration at this chromosomal region. Sequencing all exons from genomic DNA failed to disclose mutations of the folliculin gene in any of the tumors. We found a single nucleotide polymorphism (SNP) of G/A (nt 74) at the first exon in the untranslated region of the folliculin gene. We did not find a correlation between the SNP G/A or loss of the G allele and the expression level of either splice variants of the folliculin gene. Our data suggest the folliculin gene does not play a role in the tumorigenesis of sporadic chromophobe RCCs and renal oncocytomas.     

红色胶状肾透明细胞癌的临床及病理特点——附2例报告

目的探讨大体标本为红色胶状肾透明细胞癌的临床特点。方法报告2例临床发现的特殊肾透明细胞癌的诊治情况,并回顾肾癌相关文献。结果临床2例肾透明细胞癌大体标本表现为均一红色,质软,胶状的特殊特点,其影像学及病理表现为典型肾透明细胞癌。结论在肾透明细胞癌大体标本可以表现为特殊的均一红色特点,其影像学为典型肾癌,大体标本与病理分期关系不明显。     

Identification of diagnostic metabolic signatures in clear cell renal cell carcinoma using mass spectrometry imaging

Clear cell renal cell carcinoma (ccRCC) is the most common and lethal subtype of kidney cancer. Intraoperative frozen section (IFS) analysis is used to confirm the diagnosis during partial nephrectomy. However, surgical margin evaluation using IFS analysis is time consuming and unreliable, leading to relatively low utilization. In our study, we demonstrated the use of desorption electrospray ionization mass spectrometry imaging (DESI-MSI) as a molecular diagnostic and prognostic tool for ccRCC. DESI-MSI was conducted on fresh-frozen 23 normal tumor paired nephrectomy specimens of ccRCC. An independent validation cohort of 17 normal tumor pairs was analyzed. DESI-MSI provides two-dimensional molecular images of tissues with mass spectra representing small metabolites, fatty acids and lipids. These tissues were subjected to histopathologic evaluation. A set of metabolites that distinguish ccRCC from normal kidney were identified by performing least absolute shrinkage and selection operator (Lasso) and log-ratio Lasso analysis. Lasso analysis with leave-one-patient-out cross-validation selected 57 peaks from over 27,000 metabolic features across 37,608 pixels obtained using DESI-MSI of ccRCC and normal tissues. Baseline Lasso of metabolites predicted the class of each tissue to be normal or cancerous tissue with an accuracy of 94 and 76%, respectively. Combining the baseline Lasso with the ratio of glucose to arachidonic acid could potentially reduce scan time and improve accuracy to identify normal (82%) and ccRCC (88%) tissue. DESI-MSI allows rapid detection of metabolites associated with normal and ccRCC with high accuracy. As this technology advances, it could be used for rapid intraoperative assessment of surgical margin status.     

Cell‐free RNA content in urine as a possible molecular diagnostic tool for clear cell renal cell carcinoma

There is limited research on cell‐free RNA (cf‐RNA) in the urine of cancer patients. The present study was performed to detect the cf‐RNA in the urine of patients with clear cell renal cell carcinoma (ccRCC). Ninety‐five urine samples from ccRCC patients and 50 urine samples from control subjects were analyzed. The cf‐RNA integrity index was calculated by using quantitative real‐time RT‐PCR assays of the small‐sized fragment (106 bp) and the big‐sized fragment (416 bp) in GAPDH mRNA. The initial analysis showed that cf‐RNA was stable and detectable in the urine. The mean cf‐RNA integrity index was significantly lower in the urine of ccRCC patients (mean: 0.07, 95%CI: 0.05–0.10) when compared with the urine from control subjects (mean: 0.25, 95%CI: 0.16–0.33) (p < 0.001). The value of the area under the receiver‐operating characteristic curve by using the cf‐RNA integrity index for the diagnosis of ccRCC was 0.858 with a sensitivity of 68.0% and a specificity of 92.6%. Moreover, the small‐sized VEGF mRNA fragment (98 bp) was detected in 31 of 50 urine samples of patients with ccRCC and in only 2 of 50 urine samples of control subjects (p < 0.001) while the detection of the big‐sized (420 bp) VEGF mRNA fragment was an infrequent event. Our findings suggest that the small‐sized cf‐RNA in urine was more abundant in cancer patients. The tumor‐related gene VEGF mRNA fragment was detectable in the urine of cancer patients. Our finding may provide a new molecular assay for the diagnosis of renal cell carcinoma.     

代谢综合征与肾透明细胞癌相关性研究

目的 代谢综合征(metabolic syndrome,MS)是一组临床症候群,MS及其相关组分与癌症发生发展及病理特征具有密切关系.本研究旨在分析MS及其相关组分与肾透明细胞癌(clear cell cenal cell carcinoma,CCRCC)分期、分级及肿瘤大小的相关性.方法 回顾性分析2013-01-01-2015-12-30于山西医科大学第一医院就诊且病理诊断为CCRCC的375例患者的临床资料,包括年龄、性别、身高、体质量、血压、空腹血糖、生化结果、病理分期分级和肿瘤大小等.计数资料采用x2检验,计量资料以(x)±s表示,组间比较采用t检验,多因素分析采用Logistic回归分析.结果 MS组56例患者,其中男性患者32例,女性患者24例;非MS组319例患者,其中男性患者206例,女性患者113例.男女患者比较,差异无统计学意义,P=0.287.MS组与非MS组相比,年龄、吸烟、饮酒等差异无统计学意义,P值分别为0.100、0.691和0.269;而BMI指数、收缩压、空腹血糖、TG、HDL-C等差异均有统计学意义,均P＜0.001.在病理特点方面,MS与非MS相比,CCRCC病理分期(P=0.018)、分级(P=0.026)及肿瘤大小(P=0.026),差异均有统计学意义.MS相关疾病与CCRCC分期分析,糖尿病(P＜0.001)、高血压(P=0.015)、血脂紊乱(P=0.006)与CCRCC的分期有关.结论 CCRCC合并MS者病理分期较高、分级较低、肿瘤更大,糖尿病、高血压和血脂紊乱都可增加CCRCC的病理分期.     

Overexpression of the polarity protein PAR‐3 in clear cell renal cell carcinoma is associated with poor prognosis

The partition‐defective 3 (PAR‐3) protein is implicated in the development and maintenance of cell polarity and is associated with proteins that mediate the changes in cytoskeleton organization required for cell polarity establishment. In this work, we used two original primary cell lines (R‐180 and R‐305) derived from clear cell Renal Cell Carcinoma (ccRCC) surgical specimens of a patient with unfavorable clinical course (R‐180 cells) and a patient with favorable prognosis (R‐305 cells) to identify genetic and molecular features that may explain the survival difference of the two patients. The cytogenetic analysis of these cell lines revealed that the PARD3 gene was amplified only in the R‐180 cell line that was derived from an aggressive ccRCC. PARD3 gene amplification was associated with overexpression of the encoded protein and altered cytoskeleton organization. Consistently, PARD3 knockdown in R‐180 cells restored the cytoskeleton organization and reduced cell migration in comparison to non‐transfected cells. Immunohistochemical analysis of ccRCC samples from a cohort of 96 patients with a follow‐up of 6 years revealed that PAR‐3 overexpression was correlated with poor survival. Our results suggest that PAR‐3 has a role in the clinical aggressiveness of ccRCC, possibly by promoting cell migration.     

Absent Toll-like receptor-9 expression predicts poor prognosis in renal cell carcinoma

Background

Toll-like receptor 9 (TLR9) is a cellular DNA-receptor whose activation with cognate ligands triggers an immune reaction, with increased production of inflammatory cytokines. The aim of this study was to examine the expression of TLR9 in renal cell carcinoma (RCC), which is generally renowned of its immunogenic nature. We also evaluated the prognostic value of TLR9 in RCC.

Methods

TLR9 expression in RCC was characterized with immunohistochemistry in a retrospective study population of 152 RCC patients who underwent renal surgery. The TLR9 staining intensity was compared with clinical parameters.

Results

Of the studied tumours, 112 (81%) exhibited cytoplasmic TLR9 immunostaining. No association was detected between cytoplasmic TLR9 immunoexpression intensity and stage, nuclear grade, histological subtype or tumour necrosis. Cytoplasmic TLR9 immunoexpression was, however, a marker of favourable RCC specific survival both in univariate analysis and in multivariate regression model.

Conclusions

We conclude that TLR9 expression is an independent prognostic marker of RCC and the absence of TLR9 expression is related to poorer prognosis in RCC.     

Serum cell-free DNA in renal cell carcinoma: a diagnostic and prognostic marker

BACKGROUND:

Currently, there are no established diagnostic and prognostic serum markers for renal cell carcinoma (RCC). The objective of this study was to evaluate the putative significance of serum cell‐free DNA.

METHODS:

Preoperative serum samples from 200 consecutive patients with sporadic, solid renal tumors were analyzed (157 patients with RCC and 43 patients with benign renal tumors). Quantitative real‐time polymerase chain reaction was used to assess total cell‐free DNA (ring finger protein 185 [RNF185]) and CpG island methylation of Ras association domain family member 1A (RASSF1A) von Hippel‐Lindau (VHL), prostaglandin‐endoperoxidase synthase 2 (PTGS2), and P16 (cyclin‐dependent kinase inhibitor 2A). Associations with RCC, pathologic variables, and disease‐specific survival were evaluated.

RESULTS:

Total cell‐free DNA levels and CpG island methylation of RASSF1A and VHL were highly diagnostic for RCC with an area under the receiver operating characteristic curve of 0.755, 0.705, and 0.694, respectively. VHL methylation was detected more frequently in patients with clear cell RCC than in those with other subtypes (P = .007). Total cell‐free DNA levels were higher in patients with metastatic RCC (P < .001) and necrotic RCC (P = .003) and were associated with poorer disease‐specific survival (P < .001). In multivariate analysis, the tumor stage, size, grade, and necrosis (SSIGN) score (P < .001) and categorized total cell‐free DNA levels (P = .028) were retained as independent prognostic factors.

CONCLUSIONS:

The current results indicated that cell‐free DNA represents a novel serum‐based diagnostic and prognostic biomarker for RCC. Total serum cell‐free DNA levels and CpG island methylation of RASSF1A and VHL may be useful diagnostic biomarkers for RCC. VHL methylation of cell‐free DNA is suggestive of clear cell RCC. Total serum cell‐free DNA may be a useful prognostic biomarker that may assist in tailoring postoperative surveillance and therapy. External prospective validation of these data will be required. Cancer 2012;. © 2011 American Cancer Society.     

Low adiponectin levels are associated with renal cell carcinoma: a case-control study

Adiponectin is a novel endogenous insulin sensitizer, secreted by mature adipocytes. Circulating levels of adiponectin are inversely associated with obesity and insulin resistance. Because obesity is a risk factor for renal cell carcinoma (RCC), we hypothesized that low adiponectin levels are associated with RCC. To evaluate this hypothesis, we conducted a case- control study of 70 patients with histologically confirmed RCC and 280 healthy controls matched by gender, age and county of residence. Study subjects were interviewed and blood samples were collected during a 32-month period in Athens, Greece. Serum adiponectin levels were statistically, significantly and inversely associated with RCC when compared with controls (OR=0.76, p=0.05) and this association remained practically unchanged after controlling for BMI; the introduction of waist to hip ratio along with adiponectin in the multiple logistic regression analysis model rendered the association between adiponectin and RCC risk insignificant, indicating that altered levels of adiponectin may mediate the effect of central or intra-abdominal obesity on RCC. Prospective studies as well as studies exploring underlying mechanisms are needed to fully explore the role of adiponectin in predicting future risk of RCC in humans.     

Tumor enucleation: a safe treatment alternative for renal cell carcinoma

The treatment of renal cell carcinoma has evolved tremendously over the years. Initially the entire kidney was removed along with the renal tumor despite the size or extent of the mass. Early attempts to remove tumors with a normal surrounding parenchymal margin showed equivalent oncologic results in small renal masses. Attempts to preserve more renal parenchyma in patients with compromised renal function led to the enucleation of renal masses by blunt dissection following the natural plane between the peritumor pseudocapsule and the renal parenchyma. Enucleation of renal tumors has been especially useful for renal preservation in patients with preoperative renal insufficiency, solitary kidneys, multiple renal lesions and hereditary renal cell carcinoma syndromes. Comparable long-term progression and cancer-specific survival has been shown with tumor enucleation and standard partial nephrectomy. However, there has been considerable controversy regarding the safety of renal tumor enucleation due to histopathologic findings of pseudocapsule tumor invasion. Current data suggest that tumor enucleation is a safe alternative for small renal masses that are locally confined on preoperative imaging, easily delineated intraoperatively and do not appear to grossly invade beyond the pseudocapsule.     

P2X7 receptor predicts postoperative cancer‐specific survival of patients with clear‐cell renal cell carcinoma

The P2X7 receptor, an ATP‐gated plasma membrane ion channel, is involved in inflammation, apoptosis and cell proliferation, and thereby plays a crucial role during oncogenic transformation in various malignancies. This study aims to evaluate the impact of P2X7 receptor expression on postoperative cancer‐specific survival of patients with clear‐cell renal cell carcinoma (ccRCC). A total of 273 patients with ccRCC undergoing nephrectomy at a single institution were retrospectively enrolled in this study, among which 86 patients died of this disease and six patients died of other causes. Clinicopathologic features and cancer‐specific survival (CSS) were recorded. P2X7 expression was assessed by immunohistochemistry in clinical specimens. Kaplan–Meier method with log rank test was performed to compare survival curves. Cox regression models were used to evaluate the prognostic values of variables on CSS. Concordance index was calculated to assess prognostic accuracy of prognostic models. Median follow‐up period was 90 months (range, 11–120 months). Intratumoral P2X7 expression was significantly lower than peritumoral tissues (P < 0.001). Moreover, high intratumoral P2X7 expression, which was significantly associated with shorten CSS (P < 0.001), high TNM stage (P = 0.038), Fuhrman grade (P = 0.035), SSIGN (stage, size, grade, and necrosis) score (P = 0.021) and University of California Integrated Staging System (UISS) score (P = 0.007), was indicated to be an independent prognostic factor for CSS (hazard ratio [HR], 1.693; P = 0.034). The prognostic accuracy of TNM stage, UISS and SSIGN scoring models was improved when intratumoral P2X7 expression was added. Intratumoral P2X7 expression is a potential independent adverse prognostic indicator for postoperative CSS of patients with ccRCC.     

Nutlin‐3 enhances sorafenib efficacy in renal cell carcinoma

The renal cell carcinoma (RCC) is one of the top 10 cancers in USA. The renal tumors are highly angiogenic and are resistant to conventional interventions, particularly radiotherapy. The advent of multi‐specific tyrosine kinase inhibitor sorafenib has improved the progression‐free survival in RCC, but overall survival in recurrent and metastatic RCC is still a concern that has lead to characterization of combinatorial regimens. Hence, we studied the effect of combination of nutlin‐3, an MDM2 inhibitor, which increases p53 levels, and sorafenib in RCC. Sorafenib along with nutlin‐3 synergistically inhibited the cell survival and enhanced caspase‐3 cleavage leading to apoptosis in RCC. Nutlin‐3 and sorafenib were more effective in reducing the migration of RCC, in combination than as single agents. Sorafenib and nutlin‐3 decreased the phosphorylation of vascular endothelial growth factor receptor‐2 (VEGFR‐2) and ERK along with inducing p53 activity. The sorafenib and nutlin‐3 co‐treatment lead to enhanced levels of p53, p‐p53, and increase in the levels of p53 pro‐apoptotic effector PUMA, Bax, and decrease in the anti‐apoptotic Bcl‐2 levels. Importantly, our studies revealed that sorafenib alone can activate p53 in a concentration dependent manner. Thus, co‐treatment of nutlin‐3 with sorafenib leads to increased half‐life of p53, which in turn can be activated by sorafenib, to induce downstream pro‐apoptotic and anti‐proliferative effects. This is the first report showing the synergistic effect of sorafenib and nutlin‐3 while providing a strong clinical‐translational rationale for further testing of sorafenib and nutlin‐3 combinatorial regimen in human RCC. © 2011 Wiley Periodicals, Inc.     

Sarcomatoid renal cell carcinoma: Rapid dissemination detected on FDG PET‐CT

We present the FDG PET‐CT findings in a patient with persistent pain 7 weeks after a nephrectomy and lymph node dissection for a sarcomatoid renal cell carcinoma. Although conventional imaging was unable to detect evidence of metastatic spread outside the para‐aortic nodes, a PET‐CT scan showed unexpected extensive dissemination. Currently, there are no reports in the literature of the PET‐CT findings in sarcomatoid renal cell carcinomas.     

囊性肾细胞癌的CT影像诊断和病理表现

目的：分析囊性肾细胞癌的CT特征及病理表现。方法：回顾分析9例经手术病理证实且临床和影像资料完整的囊性肾细胞癌。结果：9例患者中,女性2例,男性7例,病灶均为单发,多为外生性生长。CT平扫囊性2例,囊实性7例,5例囊内容物内见碎屑或絮状物,2例囊壁见小结节状钙化。增强后囊壁、分隔及附壁结节呈不同程度强化,囊内容物未见明确强化。9例病变大体病理显示肿瘤均有厚薄不等的假纤维包膜围绕,切面见单一或大小不等的囊腔,内含浆液性或血性液体。镜下见囊腔上皮被覆肿瘤细胞。结论：囊性肾细胞癌CT表现为单发,囊壁、分隔及附壁结节呈不同程度强化,具有一定的特征性。     

Body mass index and survival in patients with renal cell carcinoma: A clinical‐based cohort and meta‐analysis

Growing evidence suggests that obesity, an established cause of renal cell cancer (RCC), may also be associated with a better prognosis. To evaluate the association between RCC survival and obesity, we analyzed a large cohort of patients with RCC and undertook a meta‐analysis of the published evidence. We collected clinical and pathologic data from 1,543 patients who underwent nephrectomy for RCC between 1994 and 2008 with complete follow‐up through 2008. Patients were grouped according to BMI (kg/m²): underweight <18.5, normal weight 18.5 to <23, overweight 23 to <25 and obese ≥25. We estimated survival using the Kaplan–Meier method and Cox proportional hazard models to examine the impact of BMI on overall survival (OS) and cancer‐specific survival (CSS) with adjustment for covariates. We performed a meta‐analysis of BMI and OS, CSS and recurrence‐free survival (RFS) from all relevant studies using a random‐effects model. The 5‐year CSS increased from 76.1% in the lowest to 92.7% in the highest BMI category. A multivariate analysis showed higher OS [hazard ratio (HR) = 0.45; 95% CI: 0.29–0.68) and CSS (HR = 0.47; 95% CI: 0.29–0.77] in obese patients than in normal weight patients. The meta‐analysis further corroborated that high BMI significantly improved OS (HR = 0.57; 95% CI: 0.43–0.76), CSS (HR = 0.59; 95% CI: 0.48–0.74) and RFS (HR = 0.49; 95% CI: 0.30–0.81). Our study shows that preoperative BMI is an independent prognostic indicator for survival among patients with RCC.