Axel Haferkamp

Cytotoxic Markers and Frequency Predict Functional Capacity of Natural Killer Cells Infiltrating Renal Cell Carcinoma

Purpose: Renal cell carcinoma harbors high numbers of infiltrating lymphocytes with apparent limited efficacy in tumor control. This study focused on the natural killer (NK) cells infiltrating renal cell carcinoma. Experimental Design: Tumor-infiltrating lymphocytes (TIL) were isolated from renal cell carcinoma and analyzed for NK cell frequency and phenotype (n = 34). NK cells were enriched and tested for effector function. Results: Two renal cell carcinoma subtypes were identified, one containing high (>20% of the lymphocyte population, n = 14), the other low (<20%, n = 20), NK cell numbers. NK cells of both groups were noncytolytic ex vivo but differed in CD16 and cytotoxic effector molecule expression as well as in their capacity to acquire cytotoxic activity: The majority of NK cells from tumors with high NK cell content (high NK-TIL) were CD16bright, whereas few CD16bright NK cells were found in tumors with low NK cell frequencies (low NK-TIL). The CD16 dichotomy correlated with different capacities to develop cytotoxicity after short-term activation with interleukin-2 ex vivo: Low NK-TIL remained noncytolytic against K562 and unresponsive to signals via the activating receptor NKp46 despite expression of receptor and adaptor molecules. In contrast, high NK-TIL acquired cytotoxic function. As described for peripheral CD16bright NK cells, NK cells from high-NK tumors showed high per cell expression of granzyme A, granzyme B, and perforin. NK cells from low NK-TIL resembled CD16neg/dim peripheral NK cells with few cytotoxin+ cells and lower expression of perforin. Conclusion: The extent of NK cell infiltration and the expression of markers (CD16 and cytotoxins) predict the functional capacity of NK cells infiltrating renal cell carcinoma and can be used to characterize subgroups of renal cell carcinoma.

Enhancer of zeste homolog 2 (EZH2) expression is an independent prognostic factor in renal cell carcinoma

BackgroundThe enhancer of zeste homolog 2 (EZH2) gene exerts oncogene-like activities and its (over)expression has been linked to several human malignancies. Here, we studied a possible association between EZH2 expression and prognosis in patients with renal cell carcinoma (RCC).MethodsEZH2 protein expression in RCC specimens was analyzed by immunohistochemistry using a tissue microarray (TMA) containing RCC tumor tissue and corresponding normal tissue samples of 520 patients. For immunohistochemical assessment of EZH2 expression, nuclear staining quantity was evaluated using a semiquantitative score. The effect of EZH2 expression on cancer specific survival (CSS) was assessed by univariate and multivariate Cox regression analyses.ResultsDuring follow-up, 147 patients (28%) had died of their disease, median follow-up of patients still alive was 6.0 years (range 0-16.1 years). EZH2 nuclear staining was present in tumor cores of 411 (79%) patients. A multivariate Cox regression analysis revealed that high nuclear EZH2 expression was an independent predictor of poor CSS (> 25-50% vs. 0%: HR 2.72, p = 0.025) in patients suffering from non-metastatic RCC. Apart from high nuclear EZH2 expression, tumor stage and Fuhrmans grading emerged as significant prognostic markers. In metastatic disease, nuclear EZH2 expression and histopathological subtype were independent predictive parameters of poor CSS (EZH2: 1-5%: HR 2.63, p = 0.043, >5-25%: HR 3.35, p = 0.013, >25%-50%: HR 4.92, p = 0.003, all compared to 0%: HR 0.36, p = 0.025, respectively).ConclusionsThis study defines EZH2 as a powerful independent unfavourable prognostic marker of CSS in patients with metastatic and non-metastatic RCC.

Molecular heterogeneity of TFE3 activation in renal cell carcinomas

Renal cell carcinomas associated with Xp11.2 translocations have recently been identified as a distinct biological entity. The translocation results in the fusion of the transcription factor TFE3 to one of several different fusion partners including PRCC, PSF, NONO, ASPL or CTLC with consecutive overexpression of the chimeric protein. As the true frequency of these neoplasms as well as the biological properties of TFE3 activation in renal cell carcinomas are largely unknown, we have examined TFE3 expression as well as the underlying genetic alterations in a large, hospital-based series of renal cell carcinomas with long-term follow-up information. Out of a total of 876 tumours, TFE3 translocations were detected in five cases (0.6%). Three additional cases were identified in a second series of cases comprising of renal cell carcinomas developing in patients before the age of 50. However, using immunohistochemistry, 9% of all renal cell carcinomas showed some degree of TFE3 reactivity. Interestingly, these cases were associated with high nuclear grade, greater tumour extent and metastatic disease as well as an unfavourable patient outcome on uni- and multivariate analysis. Fluorescence in situ hybridisation (FISH) revealed TFE3 amplifications as an additional, novel mechanism leading to increased TFE3 expression levels. In conclusion, our data show that Xp11 translocation renal cell carcinomas are uncommon tumours accounting for <1% of adult renal cell carcinomas and that the diagnosis of Xp11 translocation renal cell carcinomas needs to be verified using molecular techniques. In turn, TFE3 overexpressing tumours show an aggressive behaviour and Xp11 translocation is only one of several possible underlying genomic alterations.

Impact of Histologic Subtype on Cancer-specific Survival in Patients with Renal Cell Carcinoma and Tumor Thrombus

BACKGROUND Although different prognostic factors for patients with renal cell carcinoma (RCC) and vena cava tumor thrombus (TT) have been studied, the prognostic value of histologic subtype in these patients remains unclear. OBJECTIVE We analyzed the impact of histologic subtype on cancer-specific survival (CSS). DESIGN, SETTINGS, AND PARTICIPANTS We retrospectively analyzed the records of 1774 patients with RCC and TT who underwent radical nephrectomy and tumor thrombectomy from 1971 to 2012 at 22 US and European centers. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Multivariable ordered logistic and Cox regression models were used to quantify the impact of tumor histology on CSS. RESULTS AND LIMITATIONS Overall 5-yr CSS was 53.4% (confidence interval [CI], 50.5-56.2) in the entire group. TT level (according to the Mayo classification of macroscopic venous invasion in RCC) was I in 38.5% of patients, II in 30.6%, III in 17.3%, and IV in 13.5%. Histologic subtypes were clear cell renal cell carcinoma (cRCC) in 89.9% of patients, papillary renal cell carcinoma (pRCC) in 8.5%, and chromophobe RCC in 1.6%. In univariable analysis, pRCC was associated with a significantly worse CSS (p<0.001) compared with cRCC. In multivariable analysis, the presence of pRCC was independently associated with CSS (hazard ratio: 1.62; CI, 1.01-2.61; p<0.05). Higher TT level, positive lymph node status, distant metastasis, and fat invasion were also independently associated with CSS. CONCLUSIONS In our multi-institutional series, we found that patients with pRCC and vena cava TT who underwent radical nephrectomy and tumor thrombectomy had significantly worse cancer-specific outcomes when compared with patients with other histologic subtypes of RCC. We confirmed that higher TT level and fat invasion were independently associated with reduced CSS.

External Validation of Postoperative Nomograms for Prediction of All-Cause Mortality, Cancer-Specific Mortality, and Recurrence in Patients With Urothelial Carcinoma of the Bladder

BACKGROUND The Bladder Cancer Research Consortium (BCRC) created nomograms to predict all-cause mortality (ACM), cancer-specific mortality (CSM), and recurrence after radical cystectomy (RC) for urothelial carcinoma of the bladder (UCB). OBJECTIVE To perform a formal validation of the BCRC nomograms in a large multi-institutional patient cohort from Europe. DESIGN, SETTING, AND PARTICIPANTS Records of 2501 patients who underwent RC for UCB at eight European centers were reviewed. Complete information for external validation was available in 2404 patients for the ACM and CSM nomograms and in 2243 patients for the recurrence nomogram. MEASUREMENTS For the purpose of external validation, model discrimination was measured using the receiver operating characteristics derived area under the curve. Calibration plots examined the relationship between predicted and observed probabilities at 2 yr, 5 yr, and 8 yr. Decision curve analyses were applied to assess the net benefit derived from the three models. RESULTS AND LIMITATIONS The discrimination accuracies of the BCRC nomograms for ACM and CSM at 2 yr, 5 yr, and 8 yr after RC were 71.0%, 69.1%, and 68.2%, and 74.9%, 73.1%, and 72.4%, respectively. The accuracy of discrimination for the recurrence nomogram at the same time points was 76.5%, 75.3%, and 74.9%, respectively. Calibration plots revealed slight underestimations from ideal predictions. Decision curve analyses showed an increased net benefit for the use of the BCRC nomograms in this cohort. Limitations include the retrospective study design, potential surgeon bias, and lack of a central pathologic review. CONCLUSIONS The ACM, CSM, and recurrence nomograms showed acceptable predictive accuracies and could thus be adopted into clinical practice in UCB patients treated in Europe.

Perinephric and renal sinus fat infiltration in pT3a renal cell carcinoma: possible prognostic differences

To evaluate the influence of perinephric (PN) and renal sinus (RS) fat infiltration on cancer‐specific survival beyond other prognostic factors, as the Tumour‐Node‐Metastasis (TNM) classification system defines stage T3a renal cell carcinoma (RCC) as infiltration of perirenal fat and/or direct infiltration of the adrenal gland. Perirenal fat invasion is differentiated into RS and PN fat infiltration, but not further classified for the prognosis.

Gender-specific differences in cancer-specific survival after radical cystectomy for patients with urothelial carcinoma of the urinary bladder in pathologic tumor stage T4a

BACKGROUND Bladder cancer (UCB) staged pT4a show heterogeneous outcome after radical cystectomy (RC). No risk model has been established to date. Despite gender-specific differences, no comparative studies exist for this tumor stage. MATERIALS AND METHODS Cancer-specific survival (CSS) of 245 UCB patients without neoadjuvant chemotherapy staged pT4a, pN0-2, M0 after RC were analyzed in a retrospective multi-center study. Seventeen patients were excluded from further analysis due to carcinoma in situ (CIS) of the prostatic urethra and/or positive surgical margins. Average follow-up period was 30 months (IQR: 14-45). The influence of different clinical and histopathologic variables on CSS was determined through uni- and multivariate Cox regression analyses. Two risk groups were generated using factors with independent effect in multivariate models. Internal validity of the prediction model was evaluated by bootstrapping. RESULTS Eighty-four percent of the patients (n = 192) were male; 72% (n = 165) showed lymphovascular invasion (LVI). The 5-year CSS rate was 31%, and significantly different between male and female (35% vs. 15%, P = 0.003). Multivariate Cox regression modeling, female gender (HR = 1.83, P = 0.008), LVI (HR = 1.92, P = 0.005), and absence of adjuvant chemotherapy (HR = 0.61, P = 0.020) significantly worsened CSS. Two risk groups were generated using these 3 criteria, which differed significantly between each other in CSS (5-year-CSS: 46% vs. 12%, P < 0.001). The c-index value of the risk model was 0.61 (95% CI: 0.53-0.68, P < 0.001). CONCLUSIONS Prognosis in UCB staged pT4a is heterogeneous. Female gender and LVI are adverse factors. Adjuvant chemotherapy seems to improve outcome. The present analysis establishes the first risk model for this demanding tumor stage.

Chemoresistance is associated with increased cytoprotective autophagy and diminished apoptosis in bladder cancer cells treated with the BH3 mimetic ()-Gossypol (AT-101)

BackgroundAcquired resistance to standard chemotherapy causes treatment failure in patients with metastatic bladder cancer. Overexpression of pro-survival Bcl-2 family proteins has been associated with a poor chemotherapeutic response, suggesting that Bcl-2-targeted therapy may be a feasible strategy in patients with these tumors. The small-molecule pan-Bcl-2 inhibitor (−)-gossypol (AT-101) is known to induce apoptotic cell death, but can also induce autophagy through release of the pro-autophagic BH3 only protein Beclin-1 from Bcl-2. The potential therapeutic effects of (−)-gossypol in chemoresistant bladder cancer and the role of autophagy in this context are hitherto unknown.MethodsCisplatin (5637rCDDP1000, RT4rCDDP1000) and gemcitabine (5637rGEMCI20, RT4rGEMCI20) chemoresistant sub-lines of the chemo-sensitive bladder cancer cell lines 5637 and RT4 were established for the investigation of acquired resistance mechanisms. Cell lines carrying a stable lentiviral knockdown of the core autophagy regulator ATG5 were created from chemosensitive 5637 and chemoresistant 5637rGEMCI20 and 5637rCDDP1000 cell lines. Cell death and autophagy were quantified by FACS analysis of propidium iodide, Annexin and Lysotracker staining, as well as LC3 translocation.ResultsHere we demonstrate that (−)-gossypol induces an apoptotic type of cell death in 5637 and RT4 cells which is partially inhibited by the pan-caspase inhibitor z-VAD. Cisplatin- and gemcitabine-resistant bladder cancer cells exhibit enhanced basal and drug-induced autophagosome formation and lysosomal activity which is accompanied by an attenuated apoptotic cell death after treatment with both (−)-gossypol and ABT-737, a Bcl-2 inhibitor which spares Mcl-1, in comparison to parental cells. Knockdown of ATG5 and inhibition of autophagy by 3-MA had no discernible effect on apoptotic cell death induced by (−)-gossypol and ABT-737 in parental 5637 cells, but evoked a significant increase in early apoptosis and overall cell death in BH3 mimetic-treated 5637rGEMCI20 and 5637rCDDP1000 cells.ConclusionsOur findings show for the first time that (−)-gossypol concomitantly triggers apoptosis and a cytoprotective type of autophagy in bladder cancer and support the notion that enhanced autophagy may underlie the chemoresistant phenotype of these tumors. Simultaneous targeting of Bcl-2 proteins and the autophagy pathway may be an efficient new strategy to overcome their “autophagy addiction” and acquired resistance to current therapy.

Acetylation of histone H3 prevents resistance development caused by chronic mTOR inhibition in renal cell carcinoma cells

Chronic mTOR inhibition may induce resistance development in renal cell carcinoma (RCC). We analyzed whether long-term exposure of RCC cells to the mTOR-inhibitor RAD001 evokes resistance and whether additional targeting histone deacetylases (HDAC) by valproic acid (VPA) overcomes RAD001 resistance. It is demonstrated that responsiveness to either drug alone is lost over time, evidenced by increased cell growth, proliferation and de-differentiation. However, drug sensitivity was conserved when RAD001 and VPA were applied in concert. Molecular analysis particularly revealed strong re-activation of Akt under chronic RAD001 or diminished histone H3 acetylation under chronic VPA single drug exposure. Combined drug application did not inactivate Akt but rather resulted in H3 acetylation remaining high while RCC cell growth was still reduced. siRNA experiments revealed that histone H3 acetylation is responsible for preserving drug sensitivity in RCCs.

HDAC-inhibition counteracts everolimus resistance in renal cell carcinoma in vitro by diminishing cdk2 and cyclin A

BackgroundTargeted therapies have improved therapeutic options of treating renal cell carcinoma (RCC). However, drug response is temporary due to resistance development.MethodsFunctional and molecular changes in RCC Caki-1 cells, after acquired resistance to the mammalian target of rapamycin (mTOR)-inhibitor everolimus (Cakires), were investigated with and without additional application of the histone deacetylase (HDAC)-inhibitor valproic acid (VPA). Cell growth was evaluated by MTT assay, cell cycle progression and apoptosis by flow cytometry. Target molecules of everolimus and VPA, apoptotic and cell cycle regulating proteins were investigated by western blotting. siRNA blockade was performed to evaluate the functional relevance of the proteins.ResultsEverolimus resistance was accompanied by significant increases in the percentage of G2/M-phase cells and in the IC50. Akt and p70S6K, targets of everolimus, were activated in Cakires compared to drug sensitive cells. The most prominent change in Cakires cells was an increase in the cell cycle activating proteins cdk2 and cyclin A. Knock-down of cdk2 and cyclin A caused significant growth inhibition in the Cakires cells. The HDAC-inhibitor, VPA, counteracted everolimus resistance in Cakires, evidenced by a significant decrease in tumor growth and cdk2/cyclin A.ConclusionIt is concluded that non-response to everolimus is characterized by increased cdk2/cyclin A, driving RCC cells into the G2/M-phase. VPA hinders everolimus non-response by diminishing cdk2/cyclin A. Therefore, treatment with HDAC-inhibitors might be an option for patients with advanced renal cell carcinoma and acquired everolimus resistance.