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

Altered Expression of DDR1 in Clear Cell Renal Cell Carcinoma Correlates With miR-199a/b-5p and Patients' Outcome

BACKGROUND/AIM

Accumulating evidence suggests that discoidin domain receptor tyrosine kinase 1 (DDR1) has an oncogenic role. Therefore, the aim of this study was to evaluate the potential utility of DDR1 and its post-transcriptional repressors, miR-199a-5p and miR-199b-5p, as prognostic factors in clear cell renal cell carcinoma (ccRCC).

PATIENTS AND METHODS

The expression of DDR1 in tumor and normal renal tissues of 56 patients with ccRCC was assessed by reverse transcription quantitative polymerase chain reaction, western blotting and immunohistochemistry. Renal cancer cells were transfected with specific RNA sequences to validate DDR1 as a putative miR-199a/b-5p target.

RESULTS

Decreased DDR1 mRNA and protein, as well as miR-199a/b-5p levels were found in ccRCC. Low DDR1 protein was associated with higher nuclear grade and shorter overall survival. DDR1 immunoreactivity was elevated in the nuclei and unchanged in the membrane/cytoplasmic compartment of tumor cells. DDR1 levels correlated with those of miR-199a/b-5p. In addition, we validated DDR1 as a target gene for miR-199a/b-5p in renal cancer cell lines.

CONCLUSION

DDR1 expression is altered in ccRCC, but our findings do not support its oncogenic role. In-depth investigation will be necessary to elucidate the exact role and potential utility of miR-199a/b-5p in ccRCC.

Nuclear localization of the CK2α-subunit correlates with poor prognosis in clear cell renal cell carcinoma

Protein kinase CK2α, one of the two catalytic isoforms of the protein kinase CK2 has been shown to contribute to tumor development, tumor proliferation and suppression of apoptosis in various malignancies. We conducted this study to investigate CK2 expression in different subtypes of Renal Cell Carcinoma (RCC) and in the benign oncocytoma. qRT-PCR, immunohistochemistry and Western blot analyses revealed that CK2α expression was significantly increased at the mRNA and protein levels in clear cell RCC (ccRCC). Also the kinase activity of CK2 was significantly increased in ccRCC compared to normal renal cortex. Nuclear protein expression of CK2α correlated in univariate analysis with poor Progression Free Survival (HR = 8.11, p = 0.016). Functional analyses (cell proliferation assay) revealed an inhibitory effect of Caki-2 cell growth following CK2 inhibition with CX-4945. Our results suggest that CK2α promotes migration and invasion of ccRCC and therefore could serve as a novel prognostic biomarker and molecular therapeutic target in this type of cancer.

Suppression of immune regulatory cells with combined therapy of celecoxib and sunitinib in renal cell carcinoma

Objective

To observe the the potential benefit of sunitinib in combination with cyclooxygenase-2(COX-2) inhibitor in renal cell carcinoma therapy.

Methods

769-p cell lines were treated with sunitinib, celecoxib, or in combination at different concentrations respectively. We investigated the expression of granulocyte-macrophage colony stimulating factor (GM-CSF) in 769-p and cell proliferation in vitro. BALB/c mice implanted with Renca cells were divided into 4 groups and administered orally by gavage with sunitinib, COX-2 inhibitor (celecoxib) monotherapy or combination, and PBS respectively. Tumor growth and animal survival were observed. The myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) in peripheral blood and spleen were determined by flow cytometry. The MDSCs protein was extracted for STAT3 analysis by western blot.

Results

769-p cell lines were suppressed in a dose and time-dependent manner. The expression of GM-CSF was substantially inhibited by celecoxib and sunitinib. Combination of sunitinib and celecoxib in vivo could effectively reduce the MDSCs than those in control group. Meanwhile, the CD4⁺ lymphocytes were strongly increased and the expression of signal transducer and activator of transcription 3 (STAT3) in MDSCs were significantly reduced.

Conclusion

Combination therapy with sunitinib and celecoxib intensified the curative effects to renal cell carcinoma by suppressing immune regulatory cells.

Cabozantinib inhibits tumor growth and metastasis of a patient-derived xenograft model of papillary renal cell carcinoma with MET mutation

MET plays an important role in the development and progression of papillary renal cell carcinoma (pRCC). Evaluation of efficacy of MET inhibitors against pRCC has been hampered by limited preclinical models depicting MET abnormalities. We established a new patient-derived xenograft (PDX) model of pRCC carrying an activating mutation of MET and tested the ability of cabozantinib, an inhibitor of receptor tyrosine kinases including MET, to inhibit tumor growth and metastasis. Precision-cut, thin tissue slices from a pRCC specimen obtained by nephrectomy were implanted under the renal capsule of RAG2^-/-γC^-/- mice to establish first generation TSG-RCC-030. Histologic and genetic fidelity and metastatic potential of this model were characterized by immunohistochemistry, direct DNA sequencing and quantitative polymerase chain reaction (qPCR). The effect of cabozantinib on tumor growth and metastasis was evaluated. Whether measurements of circulating tumor DNA (ctDNA) by allele-specific qPCR could be used as a biomarker of tumor growth and response to therapy was determined. Subrenal and subcutaneous tumor grafts showed high take rates and metastasized to the lung. Both primary tumors and metastases expressed typical markers of pRCC and carried the same activating MET mutation as the parental tumor. Cabozantinib treatment caused striking tumor regression and inhibited lung metastasis in TSG-RCC-030. Plasma ctDNA levels correlated with tumor volume in control mice and changed in response to cabozantinib treatment. TSG-RCC-030 provides a realistic preclinical model to better understand the development and progression of pRCC with MET mutation and accelerate the development of new therapies for pRCC.

Obstructive sleep apnea and Fuhrman grade in patients with clear cell renal cell carcinoma treated surgically

PURPOSE

To assess the association between obstructive sleep apnea (OSA) and Fuhrman grade in patients with clear cell renal cell carcinoma (ccRCC). As secondary endpoints, we studied its association with tumor size, metastasis-free survival (MFS) and cancer-specific survival (CSS).

METHODS

We reviewed the databases of two tertiary care centers, identifying 2579 patients who underwent partial or radical nephrectomy for ccRCC between 1991 and 2014. Descriptive statistics were used to compare pathologic variables between patients with and without OSA. Linear and logistic regression models were used to assess the association of OSA with Fuhrman grade and tumor size. A Cox proportional hazards model was used to determine OSA association with MFS and CSS. A pathway analysis was performed on a cohort with available gene expression data.

RESULTS

In total, 172 patients (7 %) had self-reported OSA at diagnosis. More patients with OSA had high Fuhrman grade compared to those without OSA [51 vs. 38 %; 13 % risk difference; 95 % confidence interval (CI), 5-20 %; p = 0.003]. On multivariable analysis, the association remained significant (OR 1.41; 95 % CI 1.00-1.99; p = 0.048). OSA was not associated with tumor size (p > 0.5), MFS (p = 0.5) or CSS (p = 0.4). A trend toward vascular endothelial growth factor pathway enrichment was seen in OSA patients (p = 0.08).

CONCLUSIONS

OSA is associated with high Fuhrman grade in patients undergoing surgery for ccRCC. Pending validation of this novel finding in further prospective studies, it could help shape future research to better understand etiological mechanisms associated.

Kidney cancer and 2014: is innovation really over?

ABSTRACT 

2014 has been a year of significant innovations on kidney cancer treatments, the most relevant of which will be shown below. In particular, we analyzed the consolidated knowledge regarding the role of surgery in localized and advanced renal cell carcinoma and the targeted therapies already approved for metastatic renal cell carcinoma. Furthermore, we examined the outstanding issues, with particular reference to the choice of the second-line and the role of adjuvant and neoadjuvant treatments. Finally, we outlined the future therapeutic perspectives and those definitely abandoned.

Interactions between osteopontin and vascular endothelial growth factor: Implications for cancer

For this comprehensive review, 257 publications with the keywords "osteopontin" or "OPN" and "vascular endothelial growth factor" or "VEGF" in PubMed were screened (time frame from year 1996 to year 2014). 37 articles were excluded because they were not focused on the interactions between these molecules, and papers relevant for transformation-related phenomena were selected. Osteopontin (OPN) and vascular endothelial growth factor (VEGF) are characterized by a convergence in function for regulating cell motility and angiogenesis, the response to hypoxia, and apoptosis. Often, they are co-expressed or one molecule induces the other, however, in some settings OPN-associated pathways and VEGF-associated pathways are distinct. Their relationships affect the pathogenesis in cancer, where they contribute to progression and angiogenesis and serve as markers for poor prognosis. The inhibition of OPN may reduce VEGF levels and suppress tumor progression. In vascular pathologies, these two cytokines mediate remodeling, but may also perpetuate inflammation and narrowing of the arteries. OPN and VEGF are elevated and contribute to vascularization in inflammatory diseases.

Cancer stem cells in basic science and in translational oncology: can we translate into clinical application?

Since their description and identification in leukemias and solid tumors, cancer stem cells (CSC) have been the subject of intensive research in translational oncology. Indeed, recent advances have led to the identification of CSC markers, CSC targets, and the preclinical and clinical evaluation of the CSC-eradicating (curative) potential of various drugs. However, although diverse CSC markers and targets have been identified, several questions remain, such as the origin and evolution of CSC, mechanisms underlying resistance of CSC against various targeted drugs, and the biochemical basis and function of stroma cell-CSC interactions in the so-called ‘stem cell niche.’ Additional aspects that have to be taken into account when considering CSC elimination as primary treatment-goal are the genomic plasticity and extensive subclone formation of CSC. Notably, various cell fractions with different combinations of molecular aberrations and varying proliferative potential may display CSC function in a given neoplasm, and the related molecular complexity of the genome in CSC subsets is considered to contribute essentially to disease evolution and acquired drug resistance. In the current article, we discuss new developments in the field of CSC research and whether these new concepts can be exploited in clinical practice in the future.

Nucleobindin 2 expression is an independent prognostic factor for clear cell renal cell carcinoma

AIMS

Nucleobindin 2 (NUCB2) has been reported to play an important role in both tumorigenesis and cancer progression. This study aimed to examine the clinical significance of NUCB2 expression in clear cell renal cell carcinoma (ccRCC).

METHODS AND RESULTS

The expression level of NUCB2 and its correlation with clinicopathological parameters was analysed in 188 ccRCC tissues and adjacent non-cancerous tissues by immunohistochemistry. Samples from eight ccRCC patients were examined by Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR). Kaplan-Meier analysis and Cox proportional hazards regression models were used to investigate the correlation between NUCB2 expression and the prognosis of ccRCC patients. The expression level of NUCB2 was found to be significantly higher in ccRCC tumours compared to adjacent non-cancerous tissues using immunohistochemistry, Western blotting and qRT-PCR. Moreover, high NUCB2 tumour expression was associated with high T stage and metastasis and shorter overall survival. Univariate and multivariate analysis confirmed that NUCB2 was an independent prognostic factor for overall survival.

CONCLUSIONS

Our results show that NUCB2 plays an important role in tumorigenesis and progression and is a potential molecular biomarker for the diagnosis and targeted therapy of ccRCC.

Knowledge of genetic testing for hereditary kidney cancer in Canada is lacking: The results of the Canadian national hereditary kidney cancer needs assessment survey

INTRODUCTON

Treatment of hereditary renal cell carcinoma (HRCC) requires a multidisciplinary approach that may involve medical oncologists, geneticists, genetic counsellors, and urologists. The objective of our survey was to obtain current and representative information about the use and perceived importance of genetic testing for HRCC in Canada.

METHODS

A self-administered web-based survey was provided to Canadian medical oncologists, geneticists, genetic counsellors, and urologists in collaboration with their respective associations. The survey was created through an iterative process in consultation with the Kidney Cancer Research Network of Canada and contained both quantitative and qualitative components. The survey was designed to be exploratory and results were compared across regions.

RESULTS

The overall response was low (6.6%). Of the respondents, 42%, 33%, 19%, 5% were genetic counsellors, urologists, medical oncologists and medical geneticists, respectively. Of the respondents, 62.7% described their practice as academic, and 37.3% described it as non-academic. Non-academic respondents tended to refer for genetic counselling less frequently than academic (48.6% vs. 67.2%). Most respondents believed that genetic testing for HRCC was available (82.8%), although 47.7% did not know which tests were available. This observation was consistent across provinces. Testing for Von Hippel-Lindau syndrome was given the highest priority among respondents. Limited provider knowledge, clinical guidelines, institutional funding, access, and poor coordination between disciplines were cited as barriers to testing.

INTERPRETATION

There is a need to increase provider knowledge of genetic testing for HRCC. These findings support the development of practice guidelines and national strategies to improve coordination of specialists and access to genetics services. Limitations of the present study include low survey response which did not allow for inferential analysis by geographic region or respondent specialty.

Clinical and molecular prognostic and predictive biomarkers in clear cell renal cell cancer

ABSTRACT 

The natural history of clear cell renal cell cancer is highly unpredictable with various progressors and with populations where small renal masses may be accompanied by metastatic disease. Currently, there is a critical need to determine patient risk and optimize treatment regimes. For these patients, molecular markers may offer significant information in terms of prognostic and predictive values, as well as determination of valid therapeutic targets. Until now, only a few of the many identified clear cell renal cell cancer biomarkers have been clinically validated in large cohorts. And only several biomarkers are integrated in predictive or prognostic models. Therefore, a large cohesive effort is required to advance the field of clear cell renal cell cancer prognostic biomarkers through systematic discovery, verification, validation and clinical implementation.

Granulocyte macrophage colony-stimulating factor as a predictor of the response of metastatic renal cell carcinoma to tyrosine kinase inhibitor therapy

This prospective study was conducted to identify predictive markers for the response of metastatic renal cell carcinoma (RCC) to tyrosine kinase inhibitors (TKIs). Patients with histologically proven RCC with at least one measurable metastatic lesion were enrolled in this study. Blood samples were collected prior to treatment and the plasma levels of 27 cytokines were measured. Tumor response was assessed 8-12 weeks after the initiation of TKI treatment. A total of 13 patients (11 men and 2 women) with a median age of 63 years received sunitinib (8 cases), sorafenib (1 case), or axitinib (4 cases). Partial response (PR) was achieved in 5 patients (38%), stable disease (SD) in 4 (30%) and progressive disease (PD) was noted in 4 (30%). The plasma granulocyte macrophage colony-stimulating factor (GM-CSF) level in PR cases was significantly higher compared to that in SD or PD cases (P=0.012). Therefore, GM-CSF may be a predictive biomarker of the response of RCC to TKI treatment, suggesting that TKIs may exert clinical effects not only through suppression of the vascular endothelial growth factor, but also through immune system modulation.