Genomics and proteomics in renal cell carcinoma: Diagnosis, prognosis, and treatment selection

Downregulation of NEBL promotes migration and invasion of clear cell renal cell carcinoma by inducing epithelial-mesenchymal transition

As a member of the nebulin protein family and a structural protein of cytoskeleton, NEBL plays an important role in cardiac diseases. Recently, literature have reported the involvement of NEBL in the occurrence and development of various cancers except clear cell renal cell carcinoma (ccRCC). In this study, we found that mRNA and protein of NEBL are downregulated remarkably in ccRCC tissues based on both the TCGA database and clinical samples we collected. The areas under curve values of NEBL analyzed based on the TCGA database, qRT-PCR and IHC results were 0.9376, 0.9733 and 0.9807, respectively. The lower mRNA level of NEBL was associated with worse outcomes in ccRCC patients. When overexpressing NEBL in ccRCC cell lines, the proliferation, migration and invasion of ccRCC cells were suppressed significantly, suggesting a tumor suppressor role of NEBL. In addition, we identified that NEBL is closely related to epithelial-mesenchymal transition (EMT), thereby reducing the motility of ccRCC cells. Furthermore, the lower expression of NEBL was correlated with ccRCC patients with distant organ metastasis. In summary, we firstly described the aberrant expression of NEBL and revealed its tumor suppressor role in ccRCC. Our data support that NEBL could serve as a valuable diagnostic and prognostic biomarker in ccRCC, as well as a promising therapeutic target.

Prediction and diagnosis of renal cell carcinoma using nuclear magnetic resonance-based serum metabolomics and self-organizing maps

Diagnosis of renal cell carcinoma (RCC) at an early stage is challenging, but it provides the best chance for cure. We aimed to develop a predictive diagnostic method for early-stage RCC based on a biomarker cluster using nuclear magnetic resonance (NMR)-based serum metabolomics and self-organizing maps (SOMs). We trained and validated the SOM model using serum metabolome data from 104 participants, including healthy individuals and early-stage RCC patients. To assess the predictive capability of the model, we analyzed an independent cohort of 22 subjects. We then used our method to evaluate changes in the metabolic patterns of 23 RCC patients before and after nephrectomy. A biomarker cluster of 7 metabolites (alanine, creatine, choline, isoleucine, lactate, leucine, and valine) was identified for the early diagnosis of RCC. The trained SOM model using a biomarker cluster was able to classify 22 test subjects into the appropriate categories. Following nephrectomy, all RCC patients were classified as healthy, which was indicative of metabolic recovery. But using a diagnostic criterion of 0.80, only 3 of the 23 subjects could not be confidently assessed as metabolically recovered after nephrectomy. We successfully followed-up 17 RCC patients for 8 years post-nephrectomy. Eleven of these patients who diagnosed as metabolic recovery remained healthy after 8 years. Our data suggest that a SOM model using a biomarker cluster from serum metabolome can accurately predict early RCC diagnosis and can be used to evaluate postoperative metabolic recovery.

Histologic tumor necrosis is an independent prognostic indicator for clear cell and papillary renal cell carcinoma

Histologic tumor necrosis (TN) has been reported to indicate a poor prognosis for different human cancers. In papillary renal cell carcinoma (RCC), data regarding the prognostic impact of TN are conflicting. We retrospectively studied the pathology records of 2,333 consecutive patients who underwent nephrectomy from 1984 to 2006 at a single tertiary academic center. In multivariate analyses regarding clear cell RCC, the presence of histologic TN was an independent negative prognostic factor for metastasis-free (hazard ratio [HR], 2.32; confidence interval [CI], 1.86-2.9; P < .001) and overall (HR, 1.52; CI, 1.31-1.76; P < .001) survival. Regarding papillary RCC, the presence of histologic TN represented an independent predictor of metastasis-free (HR, 5.22; CI, 2.2-12.5; P < .001) and overall (HR, 1.69; CI, 1.11-2.58; P = .015) survival. Our findings suggest that the presence of TN is an independent predictor of clinical outcome in clear cell and papillary RCC. Thus, histologic TN might be a reliable prognostic indicator and should, therefore, routinely be examined during pathologic analysis of RCC specimens.