Value of metastin receptor immunohistochemistry in predicting metastasis after radical nephrectomy for pT1 clear cell renal cell carcinoma

Biological Features of a Renal Cell Carcinoma Cell Line Derived from Spinal Metastasis

The establishment of a metastatic renal cell carcinoma (mRCC) cell line can facilitate the search for molecular mechanisms involved in RCC metastasis. A novel human mRCC cell line, designated RCC96, was established from an mRCC of the spine from a 65-year-old Chinese man. Morphology, cell cycle phase, chromosome number, cell capability of migration, tumorigenicity in nude mice, and cytogenetic features of RCC96 were investigated. Cell growth curve was detected and the cell number doubling time was 52 h. Karyotype analysis showed that these cells were polyploidy. Transmission electron microscope showed that cells were with large atypical nuclei, well-developed rough endoplasmic reticulum, rich Golgi complex, and mitochondria, as well as visible microacinar in the cytoplasm. PCR and immunofluorescence staining demonstrated that the expression of some genes such as KISS-1, MMP2, and VEGF in RCC96 was not entirely consistent with that in other RCC cell lines, indicating the differences between primary and metastatic RCC cell lines. The RCC96 cell line may serve as a useful tool for studying the molecular pathogenesis and testing new therapeutic reagents for mRCC.

The current status of tailor-made medicine with molecular biomarkers for patients with clear cell renal cell carcinoma

Appropriate use of multiple reliable molecular biomarkers in the right context will play a role in tailormade medicine of clear cell renal cell carcinoma (RCC) patients in the future. A total of 11,056 patients from 53 studies were included in this review. The article numbers of the each evidence levels, using the grading system defined by the Oxford Centre for Evidence-based Medicine, in 1b, 2a, 2b, and 3b were 5 (9%), 18 (34%), 29 (55%), and 1 (2%), respectively. The main goal of using biomarkers is to refine predictions of tumor progression, pharmacotherapy responsiveness, and cancer-specific and/or overall survival. Currently, carbonic anhydrase (CA9) and vascular endothelial growth factor (VEGF) in peripheral blood and p53 in tumor tissues are measured to predict metastasis, while VEGF-related proteins in peripheral blood are used to assess pharmacotherapy responsiveness with sunitinib. Furthermore, interleukin 8, osteopontin, hepatocyte growth factor, and tissue inhibitors of metalloproteinases-1 in peripheral blood enable assessment of responsiveness to pazopanib treatment. Other reliable molecular biomarkers include von Hippel–Lindau gene alteration, hypoxia-inducible factor-1a, CA9, and survivin in tumor tissues and VEGF in peripheral blood for predicting cancer-specific survival. In the future, studies should undergo external validation for developing tailored management of clear cell RCC with molecular biomarkers, since individual institutional studies lack the generalization and consistency required to maintain accuracy among different patient series.

Potential of metastin and metastin receptor as biomarkers for urological cancers

AIM: To investigate the current state of the research of metastin and metastin receptor in the urological cancer field.

METHODS: For analyzing the value of metastin and metastin receptor as molecular biomarkers for the patients with urological cancer, MEDLINE database searches were performed using these terms: metastin, KISS1, kisspeptin, renal (cell) carcinoma (RCC), kidney cancer or urothelial cancer or bladder cancer or prostate cancer or testicular cancer (tumor). Since the articles were evaluated by the validity of the articles based on plausibility, credibility, and evidence levels, the articles were graded according to their level of evidence, using the grading system defined by the Oxford Centre for Evidence-based Medicine.

RESULTS: A total of six clinical studies published by individual institutions between 2003 and 2013 were included in this review. The article numbers for each of the evidence levels 2a and 2b were three (50%) and three (50%), respectively. Immunohistochemistry and reverse transcriptase-polymerase chain reaction using tumor tissues were performed to analyze in five articles (83%) and in one article (17%). The value of metastin and/or metastin receptor as molecular biomarkers in clear cell RCC, upper tract urothelial carcinoma, and bladder cancer was evaluated by multivariate analysis. Low expression of metastin receptor in clear cell RCC and low expression of metastin in upper tract urothelial carcinoma were significant risk factors for metastasis, and low metastin expression was an independent prognostic factor in bladder cancer.

CONCLUSION: Metastin and metastin receptor have potential as suitable molecular biomarkers for urological cancers. However, future studies of metastin and metastin receptor should undergo external validation to ensure consistency across different patient series, since individual institutional studies lack generalization.