Immunotherapy for renal cell carcinoma

MAGI3 enhances sensitivity to sunitinib in renal cell carcinoma by suppressing the MAS/ERK axis and serves as a prognostic marker

Clear cell renal cell carcinoma (ccRCC) exhibits considerable heterogeneity, with approximately 25% of localized cases susceptible to relapse, highlighting the challenge of the absence of reliable predictive biomarkers for personalized treatment. Meanwhile, metastatic renal cell carcinoma is characterized by unfavorable survival rates, and although Sunitinib offers partial benefits, the clinical advantages are often constrained by drug resistance and adverse side effects. Here, MAGI3 was associate with ccRCC progression, as identified through comprehensive bioinformatics analysis of clinical datasets. A low level of MAGI3 emerged as a high-risk factor for ccRCC, indicating its potential as a prognostic marker. Individuals with MAGI3 expression in middle-to-low levels displayed a significantly poorer survival rate, indicating a need for additional treatment even in the early stages of ccRCC. Furthermore, patients with MAGI3 expression in middle-to-high levels exhibited increased sensitivity to Sunitinib compared to those with lower MAGI3 levels, suggesting that individuals with MAGI3 expression at middle levels may potentially benefit from Sunitinib treatment even in the early stages of ccRCC. Through its interaction with the MAS receptor, MAGI3 has been identified as a regulator of cell proliferation and a determinant of Sunitinib resistance in ccRCC, operating via the Ang-(1-7)/MAS/ERK axis. The loss of MAGI3 expression in ccRCC patients activated the ERK signaling pathway, contributing to both cancer progression and Sunitinib resistance. Therefore, our study not only highlight MAGI3's pivotal role in ccRCC progression and Sunitinib resistance, but also reinforces MAGI3's prospective value as a predictive marker.

Sex and Gender Differences in Kidney Cancer: Clinical and Experimental Evidence

Simple Summary

Kidney cancer is a frequent malignant tumor that accounts for approximately 5% of all cancer incidences. It affects both males and females, but males are twice as likely to develop kidney cancer than females. Evidence shows that this discrepancy takes root in individual differences, such as genetics or pathologies that affect the patient. It is then reflected in the clinical characteristics of the tumors, as males have larger and more aggressive tumors. Understanding the sex- and gender-based differences in kidney cancer is essential to be able to offer patients individualized medicine that would better cover their needs in terms of prevention, diagnosis and treatment.

Abstract

Sex and gender disparities have been reported for different types of non-reproductive cancers. Males are two times more likely to develop kidney cancer than females and have a higher death rate. These differences can be explained by looking at genetics and genomics, as well as other risk factors such as hypertension and obesity, lifestyle, and female sex hormones. Examination of the hormonal signaling pathways bring further insights into sex-related differences. Sex and gender-based disparities can be observed at the diagnostic, histological and treatment levels, leading to significant outcome difference. This review summarizes the current knowledge about sex and gender-related differences in the clinical presentation of patients with kidney cancer and the possible biological mechanisms that could explain these observations. Underlying sex-based differences may contribute to the development of sex-specific prognostic and diagnostic tools and the improvement of personalized therapies.

Metabolomic study of human tissue and urine in clear cell renal carcinoma by LC-HRMS and PLS-DA

Renal cell carcinoma (RCC) is the most prevalent and lethal malignancy of the kidney. Despite all the efforts made, no tissue biomarker is currently used in the clinical management of patients with kidney cancer. A search for possible biomarkers in urine for clear cell renal cell carcinoma (ccRCC) has been conducted. Non-targeted metabolomic analyses were performed on paired samples of surgically removed renal cancer and normal tissue, as well as on urine samples. Extracts were analyzed by liquid chromatography/high-resolution mass spectrometry (LC-HRMS). Hydroxybutyrylcarnitine, decanoylcarnitine, propanoylcarnitine, carnitine, dodecanoylcarnitine, and norepinephrine sulfate were found in much higher concentrations in both cancer tissues (compared with the paired normal tissue) and in urine of cancer patients (compared with control urine). In contrast, riboflavin and acetylaspartylglutamate (NAAG) were present at significantly higher concentrations both in normal kidney tissue as well as in urine samples of healthy persons. This preliminary study resulted in the identification of several compounds that may be considered potential clear cell renal carcinoma biomarkers. Graphical abstract PLS-DA plot based on LC-MS data for normal and cancer human tissue samples. The aim of this work was the identification of up- and downregulated compounds that could potentially serve as renal cancer biomarkers.

Association between the expression of inhibitor of growth family member 4 and the progression of clear cell renal carcinoma

Inhibitor of growth family member 4 (ING4) is a candidate tumor suppressor that serves important roles in tumor growth and angiogenesis. In the present study ING4 expression was assessed in clear cell renal carcinoma (CCRC) tissues and its association with the progression of CCRC was determined. The expression of ING4 in 125 patients with CCRC was analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot analysis and immunohistochemical methods. A total of 40 adjacent normal renal tissues were used as control samples. The results identified that ING4 expression was positive in 100% of normal renal tissues, but in only 82.3% CCRC samples. RT-qPCR and western blotting results demonstrated that expression levels of ING4 mRNA and protein were significantly decreased in CCRC compared with in normal tissues (P<0.0001). ING4 expression was not associated with sex, age or tumor volume (P>0.05), but was associated with the nuclear grade of renal cancer (P<0.0001), the clinical stage of CCRC (P<0.0001) and lymphatic metastasis (P<0.0001). The results of the present study indicated that dysregulation of ING4 expression may be involved in the initiation and progression of CCRC.

Postoperative recurrence of adult renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion

Objective

To analyze the postoperative recurrence of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2 tRCC).

Methods

This retrospective study was approved by the institutional review board and performed in accordance with the ethical standards established by the institution. Demographic, clinical, pathological, and follow-up data were compiled for the study cohort.

Results

During a mean follow-up of 41.3 months (range, 3–104 months), 8 of 34 patients with Xp11.2 tRCC were confirmed to have recurrence. Three of these patients died with poor outcomes due to a vena cava tumor embolus, and one died of distant metastasis 48 months after the initial nephrectomy during which lymph node metastasis was found. Three patients survived after cytoreduction surgery. One patient was diagnosed with lung metastasis 11 months postoperatively.

Conclusions

The TNM classification provides significant prognostic information for Xp11.2 tRCC. A relatively active surveillance algorithm is recommended, and cytoreduction surgery is an effective approach for recurrent Xp11.2 tRCC. Larger studies are required to more extensively investigate the recurrence of these potentially aggressive tumors.

Lipidomic Signatures and Associated Transcriptomic Profiles of Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the most common histological type of adult kidney cancer. In this study, we obtained lipidomic profiles of clear cell RCC (ccRCC), a major RCC subtype, by performing a lipidomic analysis of specimens of cancerous tissue and the surrounding normal renal cortex obtained from the same patients (N = 49). We also compared the lipidomic profiles with the lipogenic transcriptome of specimens of cancerous tissue and the surrounding normal renal cortex for an additional set of patient samples (N = 95). Overall, we detected 326 lipids, including phospholipids, sphingolipids, neutral lipids, and eicosanoids. The levels of more than 70% of the detected lipids were significantly different (P < 0.01, corrected by the false discovery rate). The cancerous tissue was distinguished by higher levels of ether-type phospholipids, cholesterol esters, and triacylglycerols, as well as by lower levels of phospholipids (except for phosphatidylcholines) and polyunsaturated fatty acids. Characteristic changes in the levels of mRNAs and metabolites suggested that the phosphatidylethanolamine (PE) synthesis pathway is suppressed in ccRCC and associated with cell proliferation. The present study represents the lipidomic profiles of ccRCC, which provides novel information about the metabolic changes in renal cancerous tissue and RCC pathophysiology.

Analyses of potential predictive markers and survival data for a response to sunitinib in patients with metastatic renal cell carcinoma

BACKGROUND

Patients with metastatic clear cell renal cell carcinoma (ccRCC) are frequently treated with tyrosine kinase inhibitors (TKI) such as sunitinib. It inhibits angiogenic pathways by mainly targeting the receptors of VEGF and PDGF. In ccRCC, angiogenesis is characterized by the inactivation of the von Hippel-Lindau gene (VHL) which in turn leads to the induction of HIF1α target genes such as CA9 and VEGF. Furthermore, the angiogenic phenotype of ccRCC is also reflected by endothelial markers (CD31, CD34) or other tumor-promoting factors like Ki67 or survivin.

METHODS

Tissue microarrays from primary tumor specimens of 42 patients with metastatic ccRCC under sunitinib therapy were immunohistochemically stained for selected markers related to angiogenesis. The prognostic and predictive potential of theses markers was assessed on the basis of the objective response rate which was evaluated according to the RECIST criteria after 3, 6, 9 months and after last report (12-54 months) of sunitinib treatment. Additionally, VHL copy number and mutation analyses were performed on DNA from cryo-preserved tumor tissues of 20 ccRCC patients.

RESULTS

Immunostaining of HIF-1α, CA9, Ki67, CD31, pVEGFR1, VEGFR1 and -2, pPDGFRα and -β was significantly associated with the sunitinib response after 6 and 9 months as well as last report under therapy. Furthermore, HIF-1α, CA9, CD34, VEGFR1 and -3 and PDGRFα showed significant associations with progression-free survival (PFS) and overall survival (OS). In multivariate Cox proportional hazards regression analyses high CA9 membrane staining and a response after 9 months were independent prognostic factors for longer OS. Frequently observed copy number loss and mutation of VHL gene lead to altered expression of VHL, HIF-1α, CA9, and VEGF.

CONCLUSIONS

Immunoexpression of HIF-1α, CA9, Ki67, CD31, pVEGFR1, VEGFR1 and -2, pPDGFRα and -β in the primary tumors of metastatic ccRCC patients might support the prediction of a good response to sunitinib treatment.

Extended Continuous Oral Temozolomide in Patients with Progressive Metastatic Renal Cell Carcinoma Not Responding to Interferon Alpha 2b

The aim of the study was to evaluate the toxicity and efficacy of oral extended continuous temozolomide in patients with progressive metastatic renal cell carcinoma (RCC) not responding to immunotherapy after removal of the primary tumor. Patients with progressive metastatic RCC received protracted temozolomide 100 mg/m2 orally on days 1-21 every 28 days. Response was assessed after 2 cycles to be followed by another 2 cycles in the absence of progression. After 4 cycles only patients with further remission and acceptable toxicity were to continue. No objective responses were observed in 12 patients and the trial was stopped prematurely in stage 1. Six patients remained stable during 4 cycles of temozolomide (4 months), only one of these remained stable for another 2 months after having stopped treatment. Five patients progressed after the initial 2 cycles and one after the first cycle. Overall survival was 15.5 months (range 1-36 months). Repeated cycles of 3 weeks oral temozolomide 100 mg/m2 followed by one week rest proved tolerable though this regimen may only have limited activity against metastatic RCC.

Feline sarcoma-related protein expression correlates with malignant aggressiveness and poor prognosis in renal cell carcinoma

Feline sarcoma-related protein (Fer) is a ubiquitously expressed non-receptor protein tyrosine kinase associated with proliferation in various cancer cells. However, no reports have described the pathological roles and prognostic value of Fer expression in renal cell carcinoma (RCC). We investigated Fer expression in three RCC cell lines (ACHN, Caki-1, and Caki-2) and in normal tubule cells (HK-2) by immunoblotting. Fer expression was highest in ACHN cells, with Caki-1 showing intermediate levels and Caki-2 showing low levels, and was undetectable in HK-2. RNA interference was therefore used to assess the effects of Fer knockdown in ACHN. Knockdown of Fer expression was found to inhibit RCC cell proliferation and colony formation. Immunohistochemical analysis of 131 human RCC tissues (110 conventional, 11 chromophobe, and 10 papillary) investigated relationships between Fer expression and clinicopathological features, including cancer cell proliferation, apoptosis, and prognostic value for survival. In human tissues, Fer expression was significantly higher in cancer cells than in normal tubules. In addition, expression levels correlated with cancer cell proliferation, but not with apoptosis. Multivariate analysis indicated associations of Fer expression with pT stage, tumor grade, and metastasis (P < 0.001). Fer expression was also prognostic for cause-specific survival according to multivariate analysis (hazard ratio, 3.89; 95% confidence interval, 1.02-14.84, P = 0.047). Fer expression correlates with RCC cell proliferation both in vitro and in vivo, and with tumor progression and survival. This represents useful information for discussing the pathological and clinical significance of Fer in RCC.

Evaluation of cancer treatment in the abdomen: Trends and advances

Response evaluation in Oncology has relied primarily on change in tumor size. Inconsistent results in the prediction of clinical outcome when size based criteria are used and the increasing role of targeted and loco-regional therapies have led to the development of new methods of response evaluation that are unrelated to change in tumor size. The goals of this review are to expose briefly the size based criteria and to present the non-size based approaches that are currently applicable in the clinical setting. Other paths that are still being explored are not discussed in details.

Sorafenib after combination therapy with gemcitabine plus doxorubicine in patients with sarcomatoid renal cell carcinoma: a prospective evaluation

BACKGROUND

Sarcomatoid renal cell cancer (RCC) is a distinct histological variant of RCC that is associated with rapid progression and a poor prognosis. The optimal treatment for patients with sarcomatoid RCC remains to be defined. Gemcitabine plus doxorubicine (GD) has shown some efficacy, however durability of response is limited. We carried out a prospective, open-label study to investigate the efficacy and safety of sorafenib in patients after GD failure in sarcomatoid RCC.

METHODS

Fifteen patients with pure sarcomatoid RCC and objective progressive disease were treated with GD (gemcitabine 1500 mg/m², doxorubicine 50 mg/m² administered by weekly intravenous infusion) until progression of disease. Subsequently 9 patients were switched to sorafenib (400 mg twice daily). Tumor response was measured by physical examination and computerized tomography scans and evaluated according to Response Evaluation Criteria in Solid Tumors criteria.

RESULTS

Median time to progression (TTP) under GD was 6.6 months (range 0.8 - 8 months). During GD treatment there were no remissions and 6 patients died from progressive disease. Median TTP for the 9 patients switched to sorafenib was 10.9 months (range 0.6 - 25.5 months). During sorafenib therapy one patient had a partial remission lasting for 3 months and 4 patients experienced stable disease with a duration of 3 to 9 months. Four patients immediately progressed on sorafenib treatment but had a slower dynamic of tumor progression than under GD. Dosing in both treatment phases was generally well tolerated with manageable toxicities and no requirement for dose reduction.

CONCLUSIONS

Chemotherapy with GD was ineffective in our patients with pure sarcomatoid RCC. Subsequent anti-angiogenic treatment using the multi-tyrosine kinase inhibitor sorafenib resulted in additional progression-free survival in 5 of 9 patients. Further evaluation of targeted anti-angiogenic agents for the treatment of sarcomatoid RCC is warranted.

Systemic adjuvant therapies in renal cell carcinoma

Renal cell carcinoma (RCC) is one of the ten most frequent solid tumors worldwide. Recent innovations in the treatment of metastatic disease have led to new therapeutic approaches being investigated in the adjuvant setting. Observation is the only current standard of care after radical nephrectomy, although there is evidence of efficacy of adjuvant use of vaccine among all the strategies used. This article aims to collect published experiences with systemic adjuvant approaches in RCC and to describe the results of past and ongoing phase III clinical trials in this field. We explored all the systemic treatments, including chemotherapy, immunotherapy and targeted drugs while alternative approaches have also been described. Appropriate selection of patients who would benefit from adjuvant therapies remains a crucial dilemma. Although the international guidelines do not actually recommend any adjuvant treatment after radical surgery for RCC, no conclusions have yet been drawn pending the results of the promising ongoing clinical trials with the target therapies. The significant changes that these new drugs have made on advanced disease outcome could represent the key to innovation in terms of preventing recurrence, delaying relapse and prolonging survival after radical surgery for RCC.

Interferon-gamma-induced nitric oxide inhibits the proliferation of murine renal cell carcinoma cells

Renal cell carcinoma (RCC) remains one of the most resistant tumors to systemic chemotherapy, radiotherapy, and immunotherapy. Despite great progress in understanding the basic biology of RCC, the rate of responses in animal models and clinical trials using interferons (IFNs) has not improved significantly. It is likely that the lack of responses can be due to the tumor's ability to develop tumor escape strategies. Currently, the use of targeted therapies has improved the clinical outcomes of patients with RCC and is associated with an increase of Th1-cytokine responses (IFNγ), indicating the importance of IFNγ in inhibiting tumor proliferation. Thus, the present study was designed to investigate a new mechanism by which IFNγ mediates direct anti-proliferative effects against murine renal cell carcinoma cell lines. When cultured RCC cell lines were exposed to murine recombinant IFNγ, a dose dependent growth inhibition in CL-2 and CL-19 cells was observed; this effect was not observed in Renca cells. Growth inhibition in CL-2 and CL-19 cell lines was associated with the intracellular induction of nitric oxide synthase (iNOS) protein, resulting in a sustained elevation of nitric oxide (NO) and citrulline, and a decrease in arginase activity. The inhibition of cell proliferation appears to be due to an arrest in the cell cycle. The results indicate that in certain RCC cell lines, IFNγ modulates L-arginine metabolism by shifting from arginase to iNOS activity, thereby developing a potent inhibitory mechanism to encumber tumor cell proliferation and survival. Elucidating the cellular events triggered by IFNγ in murine RCC cell lines will permit anti-tumor effects to be exploited in the development of new combination therapies that interfere with L-arginine metabolism to effectively combat RCC in patients.

MG98, a second-generation DNMT1 inhibitor, in the treatment of advanced renal cell carcinoma

BACKGROUND

In carcinogenesis, methylation of DNA promoter regions results in inactivation of tumor-suppressing genes. MG98 was designed to inhibit DNA methyltransferases enzyme 1 production.

METHODS

This multicenter study explored two schedules of MG98 with Interferon-α-2β to identify schedule and dose for patients with metastatic RCC.

RESULTS

Doses of IFN 9 MIU/MG98 125 mg/m(2) for a continuous schedule and IFN 9 MIU/MG98 200 mg/m(2) for an intermittent schedule were considered the MTDs. Treatment resulted in one PR and eight SD.

CONCLUSION

MG98 combined with IFN was safe and resulted in clinical activity.

Application of ex vivo (1)H NMR metabonomics to the characterization and possible detection of renal cell carcinoma metastases

PURPOSE

Renal cell carcinoma (RCC) is the most prevalent malignancy of the kidney. Its survival rates are very low since most of patients develop metastases beyond the kidney at the time of diagnosis. Early detection is currently by far the most promising approach to reduce RCC mortality. Metabolic alterations have been suggested to have a crucial role in cancer development. Metabonomics can present a holistic picture of the metabolites alterations and provide biomarkers that could revolutionize disease characterization and detection.

METHODS

Ex vivo (1)H NMR spectra of tumors and the paired adjacent tissues obtained from living patients with RCC were recorded and analyzed using multivariate statistical techniques combined with quantitative statistical analyses.

RESULTS

In the present study, we showed that the metabonomes of RCC, either with or without metastases, differ markedly from those of their adjacent tissues. Besides, the RCC patients with metastases can be distinctly differentiated from those without metastases. Metabolic perturbations arising from malignant transformations were also systematically characterized. Compared to the adjacent tissues, RCC tumors had elevated levels of lactate, glutamate, pyruvate, glutamine, and creatine, but decreased levels of acetate, malate, and amino acids including valine, alanine, and aspartate.

CONCLUSIONS

Systemic changes in metabolite concentrations are most likely the result of cells switching to glycolysis to maintain energy homeostasis. The results suggest that metabonomics may also facilitate the discovery of novel cancer biomarkers and allows the stratification of tumors under different pathophysiological conditions, which might be a valuable future tool for RCC detection and possibly other cancers.

Fine-tuning anti-tumor immunotherapies via stochastic simulations

BACKGROUND

Anti-tumor therapies aim at reducing to zero the number of tumor cells in a host within their end or, at least, aim at leaving the patient with a sufficiently small number of tumor cells so that the residual tumor can be eradicated by the immune system. Besides severe side-effects, a key problem of such therapies is finding a suitable scheduling of their administration to the patients. In this paper we study the effect of varying therapy-related parameters on the final outcome of the interplay between a tumor and the immune system.

RESULTS

This work generalizes our previous study on hybrid models of such an interplay where interleukins are modeled as a continuous variable, and the tumor and the immune system as a discrete-state continuous-time stochastic process. The hybrid model we use is obtained by modifying the corresponding deterministic model, originally proposed by Kirschner and Panetta. We consider Adoptive Cellular Immunotherapies and Interleukin-based therapies, as well as their combination. By asymptotic and transitory analyses of the corresponding deterministic model we find conditions guaranteeing tumor eradication, and we tune the parameters of the hybrid model accordingly. We then perform stochastic simulations of the hybrid model under various therapeutic settings: constant, piece-wise constant or impulsive infusion and daily or weekly delivery schedules.

CONCLUSIONS

Results suggest that, in some cases, the delivery schedule may deeply impact on the therapy-induced tumor eradication time. Indeed, our model suggests that Interleukin-based therapies may not be effective for every patient, and that the piece-wise constant is the most effective delivery to stimulate the immune-response. For Adoptive Cellular Immunotherapies a metronomic delivery seems more effective, as it happens for other anti-angiogenesis therapies and chemotherapies, and the impulsive delivery seems more effective than the piece-wise constant. The expected synergistic effects have been observed when the therapies are combined.

Modest improvement in 20 years of kidney cancer care in the Netherlands

AIM

For an evaluation of the progress achieved in the field of kidney cancer care in the Netherlands in the last decades, we described trends in incidence, treatment, mortality and relative survival.

METHODS

All adult patients newly diagnosed with kidney cancer between 1989 and 2009 (N=32,545) were selected from the Netherlands Cancer Registry. Age-standardised incidence and mortality rates were calculated. Follow-up was completed until January 2010. In order to assess trends estimated annual percentages of change (EAPC) were estimated.

RESULTS

The incidence of kidney cancer has been fairly stable between 1989 and 2001 with a European Standardised Rate of approximately 11 per 100,000 person years (PY). Since 2001 the incidence increased to 13 per 100,000 PY in 2009 (EAPC: 2.4%; 95%confidence interval (CI): 1.5 to 3.4%). The mortality rate decreased slightly over time, from 6.2 per 100,000 PY in 1989 to 5.6 in 2010. No changes in treatment were observed, except for the introduction of targeted therapies for stage IV disease, since 2005. The 5-year relative survival improved from 51% in 1989-1994 to 58% in 2005-2009 (EAPC: 0.9%; 95%CI 0.7 to 1.2%). Improvement in survival was especially seen in males, younger age groups and low stages.

CONCLUSIONS

The incidence of kidney cancer has increased slightly, and survival improved modestly, resulting in a decreasing mortality. A positive effect of the introduction of targeted therapies for metastatic kidney cancer was observed in 1-year relative survival. For progress in kidney cancer care, effective prevention strategies and new therapies remain warranted.

Meta-analysis of clear cell renal cell carcinoma gene expression defines a variant subgroup and identifies gender influences on tumor biology

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) displays molecular and histologic heterogeneity. Previously described subsets of this disease, ccA and ccB, were defined based on multigene expression profiles, but it is unclear whether these subgroupings reflect the full spectrum of disease or how these molecular subtypes relate to histologic descriptions or gender.

OBJECTIVE

Determine whether additional subtypes of ccRCC exist and whether these subtypes are related to von Hippel-Lindau (VHL) inactivation, hypoxia-inducible factor (HIF) 1 and 2 expression, tumor histology, or gender.

DESIGN, SETTING, AND PARTICIPANTS

Six large, publicly available ccRCC gene expression databases were identified that cumulatively provided data for 480 tumors for meta-analysis via meta-array compilation.

MEASUREMENTS

Unsupervised consensus clustering was performed on the meta-arrays. Tumors were examined for the relationship of multigene-defined consensus subtypes and expression signatures of VHL mutation and HIF status, tumor histology, and gender.

RESULTS AND LIMITATIONS

Two dominant subsets of ccRCC were observed. However, a minor third cluster was revealed that correlated strongly with a wild type (WT) VHL expression profile and indications of variant histologies. When variant histologies were removed, ccA tumors naturally divided by gender. This technique is limited by the potential for persistent batch effect, tumor sampling bias, and restrictions of annotated information.

CONCLUSIONS

The ccA and ccB subsets of ccRCC are robust in meta-analysis among histologically conventional ccRCC tumors. A third group of tumors was identified that may represent a new variant of ccRCC. Within definitively clear cell tumors, gender may delineate tumors in such a way that it could have implications regarding current treatments and future drug development.

Signal transducers and activators of transcription-from cytokine signalling to cancer biology

Signal transducers and activators of transcription (STATs) are, as the name indicates, both signal transducers and transcription factors. STATs are activated by cytokines and some growth factors and thus control important biological processes. These include cell growth, cell differentiation, apoptosis and immune responses. Dysregulation of STATs, either due to constitutive activation or function impairment, can have, therefore, deleterious biological consequences. This review places particular emphasis on their structural organization, biological activities and regulatory mechanisms most commonly utilized by cells to control STAT-mediated signalling. STATs also play important roles in cancer and immune deficiencies and are thus being exploited as therapeutic targets.

Construction of a fusion expression plasmid containing the G250 gene and human granulocyte-macrophage colony stimulating factor and its significance in renal cell carcinoma

This study aimed to construct a eukaryotic expression plasmid containing the G250/MN/CA IX (G250) and human granulocyte-macrophage colony stimulating factor (hGM-CSF) genes, and to detect the expression of these proteins in vitro by recombinant plasmids in eukaryotic cells. pORF-hGM-CSF and pcDNA3.0-G250 were used as the template to amplify G250 and hGM-CSF by routine polymerase chain reaction (PCR). The two PCR products were cloned into the eukaryotic vector pVAX1, in order to construct a recombinant plasmid pVAX1-G250-hGM, and the plasmid was transfected into human embryonic kidney 293 cells. The protein expression was then determined by immunocytochemistry, atomic force microscopy, ELISA and Western blotting. DNA sequencing showed that the cloned G250 and hGM-CSF sequences were consistent with the reported Gene Bank ones. Moreover, a high expression was noted following recombinant plasmid transfection of the G250 and hGM-CSF proteins. Thus, the eukaryotic expression vector pVAX1-G250-hGM containing G250 and hGM-CSF was constructed, allowing for the investigation of the anti-G250 antigen vaccine and immune response mechanisms of biological immunotherapy in renal cell carcinoma.

Phase-II trial of combination treatment of interferon-α, cimetidine, cyclooxygenase-2 inhibitor and renin-angiotensin-system inhibitor (I-CCA therapy) for advanced renal cell carcinoma

We have recently reported favorable responses to a combination treatment comprising cimetidine, a cyclooxygenase-2 inhibitor and a renin-angiotensin-system inhibitor in metastatic renal cell carcinoma (RCC). In view of the potential synergistic effects of these three agents and interferon-α (I-CCA therapy), we conducted a phase-II trial to examine the efficacy and toxicity of I-CCA as first-line treatment. Fifty-one patients with advanced RCC received natural interferon-α (3-6 million U thrice/week) and cimetidine (800 mg), cyclooxygenase-2 inhibitor meloxicam (10 mg), and renin-angiotensin-system inhibitor candesartan (4 mg) or perindopril (4 mg) orally daily. Memorial Sloan-Kettering Cancer Center prognostic categories were favorable, intermediate and poor in 10 (20%), 31 (61%) and 10 (20%) patients, respectively. The primary end-point was the objective response rate (ORR) and the secondary end-points included clinical benefit, progression-free survival (PFS), overall survival (OS) and safety. Median follow-up was 19 months. Complete response (CR) was observed in four patients (8%) and partial response in seven (14%), yielding an ORR of 22%. None of the four patients who achieved CR relapsed during the 16- to 81-month follow up. The ORR were 17% in the favorable- or intermediate-risk group and 40% in the poor-risk group. The other 24 patients (45%) had stable disease for at least 6 months, resulting in a clinical benefit rate of 67%. The median PFS and OS were 12 and 30 months, respectively. Grade 3/4 toxicities were never observed. The I-CCA therapy, providing favorable responses and low toxicity profiles, is worthy of further consideration as a first-line therapy for metastatic RCC.

Interleukin-21: updated review of Phase I and II clinical trials in metastatic renal cell carcinoma, metastatic melanoma and relapsed/refractory indolent non-Hodgkin's lymphoma

IMPORTANCE TO THE FIELD

In advanced renal cell cancer and malignant melanoma, the current FDA approved immune modulators, such as IL-2, are the only agents which provide a durable complete remission. These responses, however, occur in < 10% of treated patients and their applicability is limited to selected patients because of their toxicity. The identification of new immunotherapeutic agents with an improved response rate and toxicity profile would represent a significant advancement in the treatment of these malignancies.

AREAS COVERED IN THIS REVIEW

This is a comprehensive review of IL-21 including its pharmacology and current developmental status. A literature review was performed using all PubMed listed publications involving IL-21, including original research articles, reviews and abstracts. It also includes a review of current ongoing trials and information from the official product website.

WHAT THE READER WILL GAIN

Recombinant IL-21 (rIL-21) is a new immune modulator currently undergoing Phase I and II testing. It is a cytokine with a four helix structure that has structural and sequence homology to IL-2 and -15, but also possesses many unique biological properties. In this review, we evaluate the development, pharmacologic properties, safety profile and current clinical efficacy of rIL-21.

TAKE HOME MESSAGE

rIL-21 has an acceptable safety profile and encouraging single agent activity in early phase renal cell carcinoma and melanoma clinical trials.

A clinical phase I/II trial with the monoclonal antibody cG250 (RENCAREX®) and interferon-alpha-2a in metastatic renal cell carcinoma patients

PURPOSE

To evaluate the efficacy and safety of WX-G250, a chimeric monoclonal antibody that binds to carboxy anhydrase IX, combined with low-dose interferon-alpha (LD-IFNα) in patients with progressive metastatic renal cell carcinoma (mRCC).

PATIENTS AND METHODS

Thirty-one patients, nephrectomized for the primary tumor, clear cell progressive mRCC, were enrolled to receive weekly infusions of WX-G250 (20 mg i.v.; week 2-12) combined with LD-IFNα (3 MIU s.c. 3 times/week; week 1-12). At week 16, patients were evaluated for response and stratified into two groups: (a) responders into the extended treatment group for an additional 6 weeks of treatment or (b) the progressive group with no further study treatment.

RESULTS

Of the 31 treated patients, 26 were evaluable for response to treatment. Two patients showed partial remission and 14 patients had stable disease as assessed in week 16. One patient experienced partial remission resulting in a complete remission lasting at least 17 months. Nine patients had durable stable disease of 24 weeks or longer. Clinical benefit was obtained in 42% (11/26) patients. The median overall survival achieved was 30 months and the 2-year survival was 57%. Patients receiving extended treatment showed a significantly longer 2-year survival rate than discontinued patients (79 vs. 30%; P=0.0083). In general, treatment was well tolerated with little toxicity.

CONCLUSION

Treatment with the antibody WX-G250 in combination with LD-IFNα is safe, well tolerated, led to clinically meaningful disease stabilization and demonstrated clinical benefit in this progressive mRCC patient population.

Unique biological properties of catalytic domain directed human anti-CAIX antibodies discovered through phage-display technology

Carbonic anhydrase IX (CAIX, gene G250/MN-encoded transmembrane protein) is highly expressed in various human epithelial tumors such as renal clear cell carcinoma (RCC), but absent from the corresponding normal tissues. Besides the CA signal transduction activity, CAIX may serve as a biomarker in early stages of oncogenesis and also as a reliable marker of hypoxia, which is associated with tumor resistance to chemotherapy and radiotherapy. Although results from preclinical and clinical studies have shown CAIX as a promising target for detection and therapy for RCC, only a limited number of murine monoclonal antibodies (mAbs) and one humanized mAb are available for clinical testing and development. In this study, paramagnetic proteoliposomes of CAIX (CAIX-PMPLs) were constructed and used for anti-CAIX antibody selection from our 27 billion human single-chain antibody (scFv) phage display libraries. A panel of thirteen human scFvs that specifically recognize CAIX expressed on cell surface was identified, epitope mapped primarily to the CA domain, and affinity-binding constants (KD) determined. These human anti-CAIX mAbs are diverse in their functions including induction of surface CAIX internalization into endosomes and inhibition of the carbonic anhydrase activity, the latter being a unique feature that has not been previously reported for anti-CAIX antibodies. These human anti-CAIX antibodies are important reagents for development of new immunotherapies and diagnostic tools for RCC treatment as well as extending our knowledge on the basic structure-function relationships of the CAIX molecule.

Update on systemic therapies of metastatic renal cell carcinoma

PURPOSE

Recent advances in understanding the molecular biology of advanced and metastatic renal cell carcinoma (RCC) have led to the development of several targeted agents that show impressive antitumor efficacy. The integration of these drugs into clinical practice has revolutionized the therapeutic management of RCC.

METHODS

We reviewed data on all approved targeted agents in the first-line and second-line setting, as well as, studies involving sequential therapy. Data from phase III trials are discussed, and an optional therapeutic algorithm is presented.

RESULTS

Sunitinib should be used as the first-line treatment of choice for good- and intermediate-risk patients according to Memorial Sloan-Kettering Cancer Center (MSKCC) criteria, whereas temsirolimus is recommended for the poor-risk group. The combination of bevacizumab and INF-alpha can be regarded as an alternative to sunitinib. After cytokine failure, patients should be recommended to sorafenib. Everolimus must be considered after first-line failure of a tyrosine kinase inhibitor (TKI); furthermore, recent evidence suggests sequential use of TKIs before administration of everolimus.

CONCLUSIONS

A range of potent drugs are available to patients with metastatic RCC. Treatment decisions should be made carefully taking into consideration that all targeted agents only have a palliative effect with prolongation of life, but do not cure metastatic RCC.

Resistance to IFN-alpha-induced apoptosis is linked to a loss of STAT2

Type I IFNs (IFN-alpha/beta) are pleitropic cytokines widely used in the treatment of certain malignancies, hepatitis B and C, and multiple sclerosis. IFN resistance is a challenging clinical problem to overcome. Hence, understanding the molecular mechanism by which IFN immunotherapy ceases to be effective is of translational importance. In this study, we report that continuous IFN-alpha stimulation of the human Jurkat variant H123 led to resistance to type I IFN-induced apoptosis due to a loss of signal transducers and activators of transcription 2 (STAT2) expression. The apoptotic effects of IFN-alpha were hampered as STAT2-deficient cells were defective in activating the mitochondrial-dependent death pathway and ISGF3-mediated gene activation. Reconstitution of STAT2 restored the apoptotic effects of IFN-alpha as measured by the loss of mitochondrial membrane potential, cytochrome c release from mitochondria, caspase activation, and ultimately cell death. Nuclear localization of STAT2 was a critical event as retention of tyrosine-phosphorylated STAT2 in the cytosol was not sufficient to activate apoptosis. Furthermore, silencing STAT2 gene expression in Saos2 and A375S.2 tumor cell lines significantly reduced the apoptotic capacity of IFN-alpha. Altogether, we show that STAT2 is a critical mediator in the activation of type I IFN-induced apoptosis. More importantly, defects in the expression or nuclear localization of STAT2 could lessen the efficacy of type I IFN immunotherapy.

Expression of apoptotic tumour necrosis factor receptor-associated factor, caspase recruitment domain and cell death-inducing DFF-45 effector genes in therapy-treated renal cell carcinoma

AIM

Dysfunction in apoptosis plays a role in development of renal cell carcinoma (RCC). This investigation aimed to identify expression of apoptosis-related genes not previously characterized in human RCC.

METHODS

The RCC ACHN cell line was treated with radiation plus interferon-alpha to induce significant apoptosis. Apoptosis RNA microarrays were used to compare control and treated RCC for apoptosis-regulatory genes with significantly altered expression (>or= twofold). Translational correlates were analysed using western blot. Immunohistochemistry of human RCC and non-cancerous kidney in tissue microarrays was also completed.

RESULTS

Several gene families, not well characterized in RCC, were significantly upregulated in RNA microarray. These were the tumour necrosis factor receptor-associated factors (TRAF1, 3 and 4), caspase recruitment domain (NOL3 and PYCARD), and cell death-inducing DFF-45 effector domain (ICAD/CAD) genes. The protein expression patterns did not always increase similarly, perhaps indicating some post-transcriptional controls needing further investigation. TRAF1 had significantly increased expression for RNA and protein (P<0.01). NOL3 had significantly decreased whole-cell protein expression (P<0.05), but had strongly localized nuclear positivity in RCC in the immunohistochemistry.

CONCLUSION

These newly identified RCC apoptosis genes have shown potential for improving outcome in other cancers and may prove to have the same potential in RCC with further study.

Motexafin gadolinium for the treatment of metastatic renal cell carcinoma: phase II study results

BACKGROUND

Thioredoxin reductase (Trx) has been implicated in activation of hypoxia-inducible factor-1alpha, which is overexpressed in > 85% of renal cell carcinomas (RCCs). We evaluated the safety and efficacy of motexafin gadolinium (MGd), a Trx inhibitor, as a single-agent therapy for metastatic RCC.

PATIENTS AND METHODS

Patients with metastatic RCC were infused daily with MGd 5 mg/kg on days 1-5 and days 15-19 of each 28-day cycle. Patients were evaluated for response on days 21-28 of every third cycle. Those with tumor response or stable disease (SD) continued treatment for < or = 12 cycles. Twenty-five patients with confirmed metastatic RCC were enrolled. All were evaluable for toxicity, and 20 were evaluable for response.

RESULTS

While no clinical responses were observed, 8 patients had SD after 3 treatment cycles, as did 4 after 6 cycles. Median overall survival was 10.1 months, and median progression- free survival was 2.7 months. The most common treatment-related toxicities were grade 1/2 pain, nausea, skin discoloration, fatigue, blisters, and headache. The most common grade 3 toxicity was hypophosphatemia, observed in 5 patients. MGd was reasonably tolerated, and disease stabilization was observed in several patients with metastatic RCC.

CONCLUSION

These results show promise for the use of MGd in combination with other molecularly targeted therapies in previously treated patients with metastatic RCC. However, further investigation of MGd alone for metastatic RCC is not recommended.

Adoptive transfer of tumor-reactive transforming growth factor-beta-insensitive cytolytic T cells for treatment of established mouse Renca tumors

OBJECTIVES

To test, using a mouse renal cancer, Renca, whether adoptive transfer of tumor-reactive transforming growth factor (TGF)-beta-insensitive cytolytic T cells can inhibit tumor progression.

METHODS

Cytolytic T cells were isolated from the spleen of male Balb/c mice repeatedly primed with irradiated Renca cells. They were expanded ex vivo and were rendered TGF-beta-insensitive by infecting with a retrovirus containing dominant negative TGF-beta type II receptor.

RESULTS

These tumor reactive TGF-beta-insensitive cytolytic T cells showed a specific and robust tumor killing activity against Renca cells, but not irrelevant cells, using an in vitro cytotoxic assay. Adoptive transfer of cytolytic T cells was performed in mice 10 days after they were challenged with Renca cells (5 x 10(5)) by tail vein injection. At 30 days after the adoptive transfer, the pulmonary tumor counts in mice who had received TGF-beta-insensitive cytolytic T cells (mean +/- standard deviation 130 +/- 140) was significantly less than those in mice that had received TGF-beta-sensitive cytolytic T cells (305 +/- 60) or in mice had received naive cytolytic T cells (375 +/- 50; P < .01). Kaplan-Meier survival analysis indicated that mice that had received adoptive transfer of TGF-beta-insensitive cytolytic T cells had a significantly greater rate of survival (75%) compared with mice that had received TGF-beta-sensitive cytolytic T cells (35%) or naive cytolytic T cells (15%), respectively (P < .05).

CONCLUSIONS

These results suggest that adoptive transfer of tumor-reactive TGF-beta-insensitive cytolytic T cells can warrant consideration for renal cell cancer immunotherapy.

Interferon-alpha (IFN-alpha)-conditioned DC preferentially stimulate type-1 and limit Treg-type in vitro T-cell responses from RCC patients

Dendritic cells (DCs) are potent antigen presenting cells and represent attractive candidates for use in novel immunotherapies for patients with renal cell carcinoma (RCC), a disease that has proven refractory to conventional treatment modalities, such as chemotherapy and radiotherapy. Given the perceived need to augment antitumor type-1 immunity (TC1 and Th1) as a therapeutic end point, and the known functional plasticity of DC populations that may display heterogeneous capacity to promote T-cell responses, we sought to identify a preferred DC preparation with this capacity. We compared 2 different preparations of monocyte-derived DC using interferon-alpha (IFN-alpha) (IFN-DC and alphaDC1) with classic DCs "matured" (mDCs) using interleukin-1beta/interleukin-6/tumor necrosis factor-alpha/prostaglandin E2, for their ability to promote autologous TC1 antitumor responses from RCC patients in vitro. IFN-alpha-conditioned DC promoted significantly higher numbers of RCC-specific CD8+ T cells exhibiting a cytotoxic phenotype after in vitro stimulation (IVS) than cytokine cocktail-mDCs. Furthermore, IVS using IFN-DCs was able to diminish regulatory-type T cells among CD4+ T-cell responder populations versus IVS using conventional mDC-based vaccines. These data emphasize an important role for IFN-alpha in modulating the immunologic functions of DCs toward a polarized DC1-type capable of coordinately promoting TH1-type and TC1-type T-cell mediated immunity and supports the translational development of patient-derived IFN-alpha-conditioned DC for use in novel immunotherapies for patients with RCC, and in whom, endogenous tumor-specific TC1 effector cells may be dysfunctional, anergic, or prone to undergo apoptosis.

Metabonomic profiling of renal cell carcinoma: high-resolution proton nuclear magnetic resonance spectroscopy of human serum with multivariate data analysis

Metabonomic profiling using proton nuclear magnetic resonance ((1)H NMR) spectroscopy and multivariate data analysis of human serum samples was used to characterize metabolic profiles in renal cell carcinoma (RCC). We found distinct, easily detectable differences between (a) RCC patients and healthy humans, (b) RCC patients with metastases and without metastases, and (c) RCC patients before and after nephrectomy. Compared to healthy human serum, RCC serum had higher levels of lipid (mainly very low-density lipoproteins), isoleucine, leucine, lactate, alanine, N-acetylglycoproteins, pyruvate, glycerol, and unsaturated lipid, together with lower levels of acetoacetate, glutamine, phosphatidylcholine/choline, trimethylamine-N-oxide, and glucose. This pattern was somewhat reversed after nephrectomy. Altered metabolite concentrations are most likely the result of the cells switching to glycolysis to maintain energy homeostasis following the loss of ATP caused by impaired TCA cycle in RCC. Serum NMR spectra combined with principal component analysis techniques offer an efficient, convenient way of depicting tumour biochemistry and stratifying tumours under different pathophysiological conditions. It may be able to assist early diagnosis and postoperative surveillance of human malignant diseases using single blood samples.

IFNalpha and IFNlambda differ in their antiproliferative effects and duration of JAK/STAT signaling activity

Interferon (IFN)lambda, also known as IL-28A, IL-28B or IL-29, is a new type III IFN, which like type I IFN(alpha/beta), activates common elements of the JAK/STAT signaling pathway and exhibits antiproliferative activity. Currently, IFNalpha is used in the treatment of certain forms of cancer, but its antitumor effects are limited and associated with high toxicity. In this study, we determined whether IFNlambda induced the same level of cell growth inhibition relative to IFNalpha. To this effect HaCaT cells, which are typically growth inhibited by IFNalpha, underwent apoptosis in response to IFNlambda. Next, in contrast to IFNalpha stimulation, IFNlambda prolonged the duration of activated STAT1 and STAT2. Furthermore, the kinetics of IFN-stimulated genes was different as IFNlambda induced a delayed but stronger induction of IFN-responsive genes. Components of the JAK/STAT pathway remained essential for the antiproliferative effects of IFNalpha and IFNlambda. IFNlambda-induced persistence of STAT activation required de novo protein synthesis and was in part due to a delay in STAT2 inactivation. Thus our data demonstrate that the duration of IFNlambda signaling is different from that of IFNalpha, and that IFNlambda could be a suitable cytokine to evaluate for cancer therapy.

Phase II studies of antiangiogenic four drug regimens for the treatment of advanced renal cell carcinoma: FUNIL-retinoid and the FUNIL-thalidomide protocols

BACKGROUND AND PURPOSE

The objective of these studies was to determine the activity of two alternative 4- drug combinations using cis-retinoic acid or thalidomide administered with a previously developed combination of 5 fluorouracil, interferon-alpha, and interleukin 2 (FUNIL), for patients with metastatic renal cell carcinoma (RRC).

METHODS

Patients enrolled in these studies had progressive measurable metastatic renal cell cancer and signed an informed consent. Treatments included continuous infusions of 5-fluorouracil, interferon-alpha, 6 MIU/m2 given subcutaneous on days 1, 3, and 5 every week, interleukin-2 6 MIU/m2/day given by continuous infusion days 2 to 5 every week, and either cis-retinoic acid at a dose of 1 mg/kg/day orally in two divided doses or thalidomide given at an initial dose of 200 mg per day. Each cycle consisted of 6 or 4 weeks of the combinations, respectively, followed by a 2-week rest. Patients were evaluated for response prior to each successive cycle. A 2-step mini-max statistical design was used.

RESULTS

In the cis-retinoid study, 20 patients were enrolled. One patient was ineligible. There were 1 complete and 2 partial responses (one confirmed and one unconfirmed) (15.8%), 1 stable disease, and 15 disease progression. In the thalidomide combination study, 20 patients were enrolled, but only 19 are assessable. One patient progressed early and was never treated. There were 2 partial responses (10.5%), 4 stable disease, and 13 progressive disease.

CONCLUSION

Neither the FUNIL-cis-retinoid nor the FUNIL-thalidomide regimens met their primary objective first step endpoint of 3 confirmed responses. Both regimens had significant adverse effects and neither is considered promising for further study.

Basal cytokines profile in metastatic renal cell carcinoma patients treated with subcutaneous IL-2-based therapy compared with that of healthy donors

Background and purpose

Metastatic renal cell carcinoma (MRCC) has a poor prognosis with a median overall survival of about one year. Since only a minority of patients experienced therapeutic benefit to current treatments, several studies have attempted to identify factors that may have an impact on response and survival. Cytokines play a crucial role in the host's immune response by regulating the development and function of a lot of biological compartments. Nevertheless, available data on basal cytokine levels in MRCC are very few and no clear profile of serum cytokines has been identified yet in these patients population. Thus, determining the levels of cytokines in MRCC could not only help in understanding the biological mechanisms of the tumor growth, but also in evaluating if different cytokine profiles are correlated with particular clinical behaviors.

Materials and methods

In 144 healthy donors and 55 MRCC treated with subcutaneous IL-2-based regimens, we analysed a panel of basal cytokines particularly involved in the neoplastic progression (IL-1beta, IL-6, IL-8, IL-10, IL-12, alpha-TNF) and C-reactive protein (CRP) in order to compare their levels in the two groups, and to verify their impact on patient response and survival.

We first compared cytokines levels in patients population and healthy donors. Than, in definite patients group, univariate and multivariate analyses were performed to evaluate the correlation existing between each factor considered and clinical outcomes. For these analyses, baseline values were included as dichotomous variables using the median values (above and below) of control group.

Results

In general, higher levels of cytokines were found in patients with respect to those of healthy donors, both in term of percentage of undetectable levels or median values. The impact on response was insignificant, except for higher levels of CRP that were strongly correlated with a worse response (p < 0.001). Within the patients groups, a worse survival was associated with higher values of CRP (8 vs 31 months, p = 0.0000), IL-6 (9 vs 25 months, p = 0.0295), and IL-8 (9 vs 17 months, p = 0.0371). Conversely, higher levels of IL-12 were associated with a better survival (25 vs 15 months, months p = 0.0882). A correlation was found between CRP and IL-6 (p = 0.009) and between CRP and IL-10 (p = 0.038). After multivariate analysis only CRP (p = 0.0035) and IL-12 (p = 0.0371) maintained an independent impact on survival, while IL-6 showed a borderline value (p = 0.0792).

Conclusion

Higher cytokines levels characterize patients population with respect to healthy donors. Moreover, higher basal level of some immunosuppressive cytokines (CRP, IL-6, IL-8) result correlated with a poorer survival, whereas higher levels of IL-12, a cytokine with a potent antineoplastic activity, was associated with a better survival. A wider sample of patients is needed to better clarify if our findings are intrinsically related to patients population or if they are simply an epiphenomenon of disease progression.

Liver resection for metastases from renal cell carcinoma

BACKGROUND

This study was conducted to evaluate the safety and efficacy of liver resection in patients with hepatic metastases from renal cell carcinoma and to identify selection criteria for patients suitable for resection.

METHODS

Between January 1988 and March 2006, 31 patients underwent liver resection for metastases from renal cell carcinoma. Patients were identified from a prospective database and retrospectively reviewed. Patient, tumor, and operative parameters were analyzed for their influence on long-term survival.

RESULTS

The overall 1-, 3- and 5-year survival rates were 82.2%, 54.3%, and 38.9%, respectively. One patient was deceased and 4 developed complications during the postoperative course. In the univariate analysis, site of the primary tumor (P = 0.013), disease-free interval (P = 0.012), and resection margins (P = 0.008) showed significant influence on long-term survival. In the multivariate analysis, only the resection margins were identified as an independent prognostic factor after liver resection.

CONCLUSIONS

Liver resection is effective and safe in the treatment of patients with hepatic metastases from renal cell carcinoma and offers the chance of long-term survival and cure. Achieving a margin-negative resection is the most important criterion in the selection of suitable patients for liver resection. However, the number of patients in the present study was small, and investigations of larger series may provide further prognostic parameters in these patients.

Immunotherapy against metastatic renal cell carcinoma with mature dendritic cells

OBJECTIVE

We performed a clinical trial of immunotherapy using autologous mature dendritic cells (DC) pulsed with autologous tumor lysate, for patients with metastatic renal cell carcinoma (RCC).

METHODS

Patients with refractory metastatic RCC were enrolled in the study. All of them received interferon (IFN)-alpha treatment after nephrectomy and were followed over 3 months prior to this study. Autologous monocyte-derived immature DC were pulsed with lysate from autologous primary tumor as the antigen and keyhole limpet hemocyanin (KLH) as immunomodulator, and cultured in the presence of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and prostaglandin (PG)E2 to generate mature DC. Mature DC were injected intradermally near bilateral inguinal lymph nodes of the patients. A delayed-type hypersensitivity (DTH) test and enzyme-linked immunospot (ELISPOT) assay were performed to evaluate the immunological response. After 4 months from first injection, the clinical effect was evaluated by diagnostic imaging.

RESULTS

The treatments were well tolerated without significant toxicity by the patients who were an average of 65.7 years old and had multiple metastases in the lung and other organs. One of the two patients developed a positive DTH reaction to tumor lysate and the other patient only to KLH. The patient with a positive DTH reaction to tumor lysate had stable disease in the clinical evaluation.

CONCLUSIONS

We confirmed the safety of DC therapy in this clinical trial. The DTH test revealed that the DC therapy induced immunological response to RCC. On the other hand, it was necessary to reconsider the patient selection criteria.

A Mutation in the SH2 domain of STAT2 prolongs tyrosine phosphorylation of STAT1 and promotes type I IFN-induced apoptosis

Type I interferons (IFN-alpha/beta) induce apoptosis in certain tumor cell lines but not others. Here we describe a mutation in STAT2 that confers an apoptotic effect in tumor cells in response to type I IFNs. This mutation was introduced in a conserved motif, PYTK, located in the STAT SH2 domain, which is shared by STAT1, STAT2, and STAT3. To test whether the tyrosine in this motif might be phosphorylated and affect signaling, Y631 of STAT2 was mutated to phenylalanine (Y631F). Although it was determined that Y631 was not phosphorylated, the Y631F mutation conferred sustained signaling and induction of IFN-stimulated genes. This prolonged IFN response was associated with sustained tyrosine phosphorylation of STAT1 and STAT2 and their mutual association as heterodimers, which resulted from resistance to dephosphorylation by the nuclear tyrosine phosphatase TcPTP. Finally, cells bearing the Y631F mutation in STAT2 underwent apoptosis after IFN-alpha stimulation compared with wild-type STAT2. Therefore, this mutation reveals that a prolonged response to IFN-alpha could account for one difference between tumor cell lines that undergo IFN-alpha-induced apoptosis compared with those that display an antiproliferative response but do not die.

Combination therapy of an orthotopic renal cell carcinoma model using intratumoral vector-mediated costimulation and systemic interleukin-2

PURPOSE

Interleukin (IL)-2 therapy is currently used for therapy of renal cell carcinoma (RCC). However, it is only effective in approximately 10% to 15% of patients, showing a need for additional therapies. We have previously described a replication-defective fowlpox vector encoding three costimulatory molecules (B7-1, ICAM-1, and LFA-3), designated rF-TRICOM. Here, we show that intratumoral administration of rF-TRICOM in an orthotopic RCC model effectively enhances tumor immunogenicity and reduces tumor burden in mice and the combination of rF-TRICOM and IL-2 is more effective than either therapy alone.

EXPERIMENTAL DESIGN

RCC cells were implanted under the capsule of the kidney, and mice were given rF-TRICOM intratumorally 14 days later. We compared the effect of rF-TRICOM, rF-granulocyte macrophage colony-stimulating factor (GM-CSF), and two doses of IL-2 and combinations of the above on antitumor efficacy and survival. Host CD4(+) and CD8(+) T-cell responses were also evaluated.

RESULTS

The results show that (a) systemic IL-2 therapy was moderately effective in the reduction of tumor burden in an orthotopic RCC model; (b) a single intratumoral injection of rF-TRICOM and rF-GM-CSF significantly reduced tumor burden; (c) the addition of systemic IL-2 to intratumoral rF-TRICOM/rF-GM-CSF administration resulted in further reduction of tumor burden, decrease in the incidence of metastasis, and extended survival in tumor-bearing mice above that seen with either treatment alone; and (d) CD8(+) T cells played a critical role in the antitumor effect seen with rF-TRICOM/rF-GM-CSF + IL-2 therapy. Finally, the addition of systemic recombinant IL-15 or intratumoral vector-delivered IL-15 to intratumoral rF-TRICOM/rF-GM-CSF administration resulted in substantially more tumor-free mice than either therapy alone.

CONCLUSIONS

These studies show that intratumoral administration of rF-TRICOM admixed with rF-GM-CSF is effective at reducing tumor burden in mice and the addition of IL-2 further contributes to this effect. These studies thus form the rationale for combination immunotherapy clinical trials in patients with RCC.

Phase I trial of sorafenib in combination with IFN alpha-2a in patients with unresectable and/or metastatic renal cell carcinoma or malignant melanoma

PURPOSE

To determine the safety, maximum tolerated dose, pharmacokinetics, and efficacy, and to evaluate biomarkers, of the multikinase inhibitor sorafenib plus IFN alpha-2a in advanced renal cell carcinoma (RCC) or melanoma.

EXPERIMENTAL DESIGN

Patients received 28-day cycles of continuous, oral sorafenib twice daily and s.c. IFN thrice weekly: sorafenib 200 mg twice daily plus IFN 6 million IU (MIU) thrice weekly (cohort 1); and sorafenib 400 mg twice daily plus IFN 6 MIU thrice weekly (cohort 2); or plus IFN 9 MIU thrice weekly (cohort 3). Tumor response was assessed by Response Evaluation Criteria in Solid Tumors and dynamic contrast-enhanced ultrasonography.

RESULTS

Thirteen patients received at least one dose of sorafenib plus IFN (12 RCC; one melanoma). The maximum tolerated dose was not reached [only one dose-limiting toxicity (grade 3 asthenia)]. Most frequently reported drug-related adverse events were grade 2 or less in severity, including fatigue, diarrhea, nausea, alopecia, and hand-foot skin reaction. One (7.7%) RCC patient achieved partial response and eight (61.5%) had stable disease (including the melanoma patient). Good responders assessed by dynamic contrast-enhanced ultrasonography had increased progression-free survival and overall survival, relative to poor responders. IFN had no effect on the pharmacokinetics of sorafenib. There were no significant changes in absolute values of lymphocytes, levels of proangiogenic cytokines, or inhibition of phosphorylated extracellular signal-regulated kinase in T cells or natural killer cells, with combination therapy.

CONCLUSIONS

This sorafenib combination was well tolerated, with preliminary antitumor activity in advanced RCC and melanoma patients. There were no drug-drug interactions and the recommended dose for future studies is sorafenib 400 mg twice daily plus IFN 9 MIU.

Translational mini-review series on vaccines: Dendritic cell-based vaccines in renal cancer

Renal cancer is a relatively uncommon solid tumor, accounting for about 3% of all adult malignancies, however this rate incidence is rising. The most common histological renal cell carcinoma (RCC) subtype is clear cell carcinoma that makes up approximately 70-80% of all renal neoplasms and appears to be the only histological subtype that is responsive to immunotherapeutic approaches with any consistency. Therefore, it has been hypothesized that immune-mediated mechanisms play important roles in limiting tumor growth and that dendritic cells (DC), the most potent APC in the body, and T cells are the dominant effector cells that regulate tumor progression in situ. In this context, the development of clinically effective DC-based vaccines is a major focus for active specific immunotherapy in renal cancer. In the current review we have not focused on the results of recently published RCC clinical trials, as several excellent reviews have already performed this function. Instead, we turned our attention to how the perception and practical application of DC-based vaccinations are evolving.