The place of VEGF inhibition in the current management of renal cell carcinoma

Successful long-term management of metastatic clear cell renal cell carcinoma with nivolumab: a case report and literature review

In Colombia, renal cancer is a rare condition, with clear cell renal cell carcinoma (ccRCC) being the most prevalent neoplasm. In recent years, immune checkpoint inhibitors (ICI) have been proposed for the management of metastatic disease, as they have shown improved rates of response and long-term survival. Furthermore, they exhibit a favourable tolerance profile, and adverse events causing significant morbidity are infrequent. We report the case of a 61-year-old male patient initially diagnosed with early-stage ccRCC who underwent right nephrectomy in 2009. Six years later, disease recurrence with metastatic compromise was documented, which led to the resection of the L1 vertebral body followed by radiotherapy and maintenance treatment with sunitinib. Due to disease progression, treatment with sunitinib was discontinued. Subsequently, everolimus was initiated as second-line immunotherapy, which was later discontinued due to the appearance of new metastatic lesions. In 2017, the patient was referred to our institution, where a third-line pharmacological treatment with nivolumab was initiated. In 2022, complete remission by positron emission tomography-computed tomography (PET-CT) was evidenced, which has been sustained to date. This case demonstrates the efficacy and safety of ICI in patients with metastatic ccRCC. The case presented is relevant in that it describes the achievement of complete remission in a patient who did not respond to the first two lines of immunotherapy. Given the limited literature regarding the discontinuation of therapy after achieving sustained remission, further research is warranted to explore this topic.

TOLLIP Protein Expression Predicts Unfavorable Outcome in Renal Cell Carcinoma

Resistance to systemic therapy is one of the hallmarks of renal cell carcinoma (RCC). Recently, TOLLIP has emerged as a possible driver of autophagy and chemoresistance. We explored the relationship between primary and metastatic RCC tumor characteristics, patient survival, and TOLLIP expression. The tissue microarrays cohort contained 95 cores of the primary tumor, matched metastases, and matched adjacent tissues derived from 32 RCC patients. TOLLIP expression in tumor samples was evaluated using the H-score. All examined samples showed cytoplasmic TOLLIP expression, with a median value of 100 in primary tumors, 107.5 in metastases, and 220 in the control group. The expression was significantly higher in the normal adjacent tissues compared to primary or metastatic RCC (p < 0.05). We found a positive correlation between expressions of TOLLIP in the primary tumor and its metastases (p < 0.05; k = 0.48). TOLLIP expression significantly correlates with a lower overall survival rate (p = 0.047). TOLLIP functions as a ubiquitin-LC3 adaptor in the intracellular pathway associated with autophagy. Relative TOLLIP overexpression may augment autophagy-related signaling, limiting susceptibility to therapy. The blockade of TOLLIP physiological function seems to be a promising approach to overcoming resistance to systemic therapy.

Anti-angiogenesis Revisited: Combination with Immunotherapy in Solid Tumors

PURPOSE OF REVIEW

Both anti-angiogenesis and immunotherapy are well-established therapeutic options in solid tumors. Here, we review the rationale as well as clinical evidence of combining these two approaches.

RECENT FINDINGS

There is strong rationale and substantial preclinical and clinical evidence that anti-angiogenesis plays a pivotal role in overcoming immunotherapy resistance. The combination of an anti-angiogenic agent and a checkpoint inhibitor offers a more robust treatment option in many clinical trials in a wide variety of solid tumor types. Combination of anti-angiogenesis and immunotherapy has emerged as a standard of care in some tumor types and the indication is expected to expand to more tumor types in the years to come.

Oncogenic effects of RAB27B through exosome independent function in renal cell carcinoma including sunitinib-resistant

Exosomes are 40–100 nm nano-sized extracellular vesicles. They are released from many cell types and move into the extracellular space, thereby transferring their components to recipient cells. Exosomes are receiving increasing attention as novel structures participating in intracellular communication. RAB27B is one of the leading proteins involved in exosome secretion, and oncogenic effects have been reported in several cancers. In recent years, molecularly targeted agents typified by sunitinib are widely used for the treatment of metastatic or recurrent renal cell carcinoma (RCC). However, intrinsic or acquired resistance to sunitinib has become a major issue. The present study aimed to elucidate the role of RAB27B in RCC including sunitinib-resistant and its role in exosomes. Bioinformatic analyses revealed that high expression of RAB27B correlates with progression of RCC. The expression of RAB27B protein in RCC cell lines was significantly enhanced compared with that in normal kidney cell lines. Furthermore, RAB27B protein expression was enhanced in all of the tested sunitinib-resistant RCC cell lines compared to parental cells. Although no specific effect of RAB27B on exosomes was identified in RCC cells, loss-of-function studies demonstrated that knockdown of RAB27B suppressed cell proliferation, migration and invasive activities. Moreover, anti-tumor effects of RAB27B downregulation were also observed in sunitinib-resistant RCC cells. RNA sequence and pathway analysis suggested that the oncogenic effects of RAB27B might be associated with MAPK and VEGF signaling pathways. These results showed that RAB27B is a prognostic marker and a novel therapeutic target in sunitinib-sensitive and -resistant RCCs. Further analyses should improve our understanding of sunitinib resistance in RCC.

Sunitinib (Sutent®): A novel agent for the treatment of metastatic renal cell carcinoma

Objective. To provide a review of the clinical data supporting the use of sunitinib (Sutent®), a multitargeted, small molecule, tyrosine kinase inhibitor, with focus on its approved indication for the treatment of advanced renal cell carcinoma in patients with metastatic disease requiring drug therapy.Data sources. A MEDLINE search of the medical literature was conducted using the terms ‘sunitinib’ and ‘SU11248’. References from the articles were reviewed and relevant sources were included. Data summary. The introduction of dual tyrosine kinase receptor inhibitors is a novel approach to treating advanced metastatic renal cell carcinoma (mRCC) by preventing angiogenesis and tumor growth. Based on its ability to inhibit several targets involved in angiogenesis and endothelial cell proliferation, sunitinib offers patients with mRCC an alternative for treatment. A recent Phase III study evaluating sunitinib as first-line therapy showed a significant difference when compared to interferonalfa (IFN-α) for a progression-free survival of 11 months in the sunitinib arm and 5 months in the IFN-α arm (hazard ratio 0.42; 95% CI 0.32–0.54; P50.001). Two Phase II trials determined sunitinib was effective as second-line therapy in mRCC patients who failed previous cytokine treatment. Partial response rates were 40% (95% CI 28%–53%) and 34% (95% CI 25%–44%). Multiple ongoing trials are currently underway to evaluate sunitinib for first-line therapy in mRCC. J Oncol Pharm Practice (2007) 13: 5–16.

Chemical generation of bispecific antibodies

Bispecific antibodies (BsAbs) are regarded as promising therapeutic agents due to their ability to simultaneously bind two different antigens. Several bispecific modalities have been developed, but their utility is limited due to problems with stability and manufacturing complexity. Here we report a versatile technology, based on a scaffold antibody and pharmacophore peptide heterodimers, that enables rapid generation and chemical optimization of bispecific antibodies, which are termed bispecific CovX-Bodies. Two different peptides are joined together using a branched azetidinone linker and fused to the scaffold antibody under mild conditions in a site-specific manner. Whereas the pharmacophores are responsible for functional activities, the antibody scaffold imparts long half-life and Ig-like distribution. The pharmacophores can be chemically optimized or replaced with other pharmacophores to generate optimized or unique bispecific antibodies. As a prototype, we developed a bispecific antibody that binds both vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang2) simultaneously, inhibits their function, shows efficacy in tumor xenograft studies, and greatly augments the antitumor effects of standard chemotherapy. This unique antiangiogenic bispecific antibody is in phase-1 clinical trials.

Antitumor effects of a combination of interferon-alpha and sorafenib on human renal carcinoma cell lines

To support the role of interferon (IFN)-alpha and sorafenib combination therapy against renal cell carcinoma (RCC), the effects of IFN-alpha and sorafenib on tumor growth, vascular endothelial growth factor (VEGF) production, and phosphorylation levels of extracellular signal-regulated kinase (ERK) and mitogen-activated protein/ERK kinase (MEK) were examined using several cultured RCC cell lines (ACHN, Caki-1, Caki-2, SMKT-R1, SMKT-R2, SMKT-R3 and SMKT-R4). IFN-alpha or sorafenib alone inhibited the proliferation of all the cell lines except Caki-2, while combined treatment with the two agents showed enhanced inhibitory effects compared to treatment with each agent alone. VEGF production was inhibited by IFN-alpha alone in ACHN and SMKT-R2 cells and by sorafenib alone in ACHN, Caki-1, SMKT-R1 and SMKT-R2 cells. However, sorafenib increased VEGF production by Caki-2 cells. Interestingly, combined treatment with the two agents suppressed VEGF production by SMKT-R1 and SMKT-R2 cells more strongly than IFN-alpha or sorafenib alone. Although phosphorylated ERK (p-ERK) was increased after 30 min of treatment with IFN-alpha alone, no difference was observed between control and IFN-alpha-treated cells after 2 h. Sorafenib decreased p-ERK in ACHN, Caki-1, SMKT-R1 and SMKT-R2 cells, but increased p-ERK in Caki-2, SMKT-R3 and SMKT-R4 cells, after 2 h. Combined treatment with IFN-alpha and sorafenib decreased p-ERK compared to treatment with each agent alone in all cell lines except Caki-2. However, IFN-alpha did not inhibit the p-ERK increase induced by sorafenib in Caki-2 cells. Phosphorylated MEK showed similar patterns to p-ERK after the various treatments. In conclusion, combined treatment with IFN-alpha and sorafenib suppressed cell proliferation and VEGF production more strongly than treatment with each agent alone in several RCC cell lines.

A cryptic vascular endothelial growth factor T-cell epitope: identification and characterization by mass spectrometry and T-cell assays

Vascular endothelial growth factor (VEGF) is involved in various physiologic processes, such as angiogenesis or wound healing, but is also crucial in pathologic events, such as tumor growth. Thus, clinical anti-VEGF treatments have been developed that could already show beneficial effects for cancer patients. In this article, we describe the first VEGF-derived CD8(+) T-cell epitope. The natural HLA ligand SRFGGAVVR was identified by differential mass spectrometry in two primary renal cell carcinomas (RCC) and was significantly overpresented on both tumor tissues. SRFGGAVVR is derived from a cryptic translated region of VEGF presumably by initiation of translation at the nonclassic start codon CUG(499). SRFGGAVVR-specific T cells were generated in vitro using peptide-loaded dendritic cells or artificial antigen-presenting cells. SRFGGAVVR-specific CD8(+) T cells, identified by HLA tetramer analysis after in vitro stimulation, were fully functional T effector cells, which were able to secrete IFN-gamma on stimulation and killed tumor cells in vitro. Additionally, we have quantitatively analyzed VEGF mRNA and protein levels in RCC tumor and normal tissue samples by gene chip analysis, quantitative reverse transcription-PCR, in situ hybridization, and bead-based immunoassay. In the future, T cells directed against VEGF as a tumor-associated antigen may represent a possible way of combining peptide-based anti-VEGF immunotherapy with already existent anti-VEGF cancer therapies.

Genomic assessment of a multikinase inhibitor, sorafenib, in a rodent model of pulmonary hypertension

Pulmonary hypertension (PH) and cancer pathology share growth factor- and MAPK stress-mediated signaling pathways resulting in endothelial and smooth muscle cell dysfunction and angioproliferative vasculopathy. In this study, we assessed sorafenib, an antineoplastic agent and inhibitor of multiple kinases important in angiogenesis [VEGF receptor (VEGFR)-1-3, PDGF receptor (PDGFR)-beta, Raf-1 kinase] as a potential PH therapy. Two PH rat models were used: a conventional hypoxia-induced PH model and an augmented PH model combining dual VEGFR-1 and -2 inhibition (SU-5416, single 20 mg/kg injection) with hypoxia. In addition to normoxia-exposed control animals, four groups were maintained at 10% inspired O(2) fraction for 3.5 wk (hypoxia/vehicle, hypoxia/SU-5416, hypoxia/sorafenib, and hypoxia/SU-5416/sorafenib). Compared with normoxic control animals, rats exposed to hypoxia/SU-5416 developed hemodynamic and histological evidence of severe PH while rats exposed to hypoxia alone displayed only mild elevations in hemodynamic values (pulmonary vascular and right ventricular pressures). Sorafenib treatment (daily gavage, 2.5 mg/kg) prevented hemodynamic changes and demonstrated dramatic attenuation of PH-associated vascular remodeling. Compared with normoxic control rats, expression profiling (Affymetrix platform) of lung RNA obtained from hypoxia [false discovery rate (FDR) 6.5%]- and hypoxia/SU-5416 (FDR 1.6%)-challenged rats yielded 1,019 and 465 differentially regulated genes (fold change >1.4), respectively. A novel molecular signature consisting of 38 differentially expressed genes between hypoxia/SU-5416 and hypoxia/SU-5416/sorafenib (FDR 6.7%) was validated by either real-time RT-PCR or immunoblotting. Finally, immunoblotting studies confirmed the upregulation of the MAPK cascade in both PH models, which was abolished by sorafenib. In summary, sorafenib represents a novel potential treatment for severe PH with the MAPK cascade a potential canonical target.

A novel murine model of allogeneic vaccination against renal cancer

OBJECTIVES

To develop a murine model for whole-cell allogeneic vaccination in renal cancer, as such vaccines aim to direct immune responses against patient tumour cells, due to shared antigens between the vaccine and tumour cells.

MATERIALS AND METHODS

A novel murine renal cell line, allogeneic to BALB/c, was developed from a C57BL/6 mouse by primary cell culture (RVIK). It was immortalized by HPV16 E6/E7 and transfected with ras in an attempt to improve its immunogenicity. The cell line was characterized and tested as a vaccine in a BALB/c tumour-protection model after subsequent tumour challenge with autologous RenCa tumour cells.

RESULTS

RVIK alone, with no ras induced cross-reactive immunity, providing a valid non-tumorigenic allogeneic whole-cell vaccine model for renal cancer. Ras transfection per se did not improve RVIK immunity.

CONCLUSIONS

RVIK is a novel immunogenic murine renal epithelial cell line, which confers protection when used as an allogeneic vaccine. It provides proof of principle for the effectiveness of allogeneic whole-cell vaccines and may therefore form the basis of a useful model of allogeneic vaccination to further optimize vaccination schedules, formulation and adjuvants for a clinical setting.

VEGF and VEGFR-1 are coexpressed by epithelial and stromal cells of renal cell carcinoma

BACKGROUND

Tumor angiogenesis is a dynamic process that plays a major role in cancer progression. Vascular endothelial growth factor (VEGF) and its receptors play a pivotal role in angiogenesis. The expression of VEGF and its receptors VEGFR-1 and VEGFR-2 in renal cell carcinoma (RCC) was investigated in the perspective of anti-VEGF treatments.

METHODS

Total VEGF protein levels were quantified by enzyme-linked immunosorbent assay (ELISA) in tumor tissue samples from surgical specimens of 65 patients with clear cell RCC. At the cellular level the VEGF isoforms VEGFR-1 and VEGFR-2 mRNA were quantified by real-time quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) in laser-microdissected tumoral epithelial as stromal cells and in corresponding normal tissue compartments. Colocalization of VEGF and VEGFR-1 proteins was studied by triple immunofluorescent labeling.

RESULTS

Protein VEGF in cytosolic extracts was significantly higher in tumoral than in nontumoral tissue (P< .0001). Event-free survival was significantly longer for patients with cytosolic VEGF lower than the cutoff (75th percentile of VEGF protein levels, P= .02). In laser-microdissected epithelial cells, VEGF(121) and VEGFR-1 mRNA expressions were higher in RCC than in corresponding nontumoral kidney (P= .007 and P= .002, respectively); they were also higher in stromal cells of RCC compared with nontumoral kidney (P= .02 and P= .003, respectively). There was no differential VEGFR-2 expression in epithelial or in stromal cells of tumoral or nontumoral kidney. By immunofluorescent labeling VEGF and VEGFR-1 colocalized on RCC tumor epithelial and stromal cells.

CONCLUSIONS

Combined laser microdissection and quantitative RT-PCR, as triple immunofluorescent labeling, underlined the preferential expression of the most soluble VEGF isoform, VEGF(121), and its receptor VEGFR-1, but not VEGFR-2, in epithelial and stromal cells of RCC.

No role of adjuvant systemic therapy after complete metastasectomy in metastatic renal cell carcinoma?

OBJECTIVE

To compare the effects of metastasectomy combined with immunotherapy and metastasectomy alone in the treatment of patients with metastatic renal cell carcinoma.

MATERIALS AND METHODS

A total of 93 patients who had undergone metastasectomy were included in the study. Patients were categorized according to immunotherapy status, including the immunotherapy group (n = 70) and the no immunotherapy group (n = 23).

RESULTS

In the immunotherapy group, median overall survival was 56.1 months (95% confidence interval [CI] 34.1-78.2), whereas the no immunotherapy group reached a median overall survival of 21.3 months (95% CI 3.4-39.2), respectively. The 1, 3, and 5-year overall survival rates were calculated at 67.1% and 56.5%, 30.0% and 34.8%, and 7.1% and 19.0%, for the immunotherapy group and the no immunotherapy group, respectively (P = 1.000). When patients were stratified according to the time of metastasis, overall survival was not significantly different among the groups in patients with synchronous metastasis or in those with metachronous metastasis. Multivariate Cox proportional hazards model analysis showed that multiplicity of metastasis (odds ratio 3.68; 95% CI 1.85-7.34; P < 0.001) and metastatic sites (odds ratio 2.12; 95% CI 1.15-3.90; P = 0.016) were independent predictors of overall survival.

CONCLUSIONS

Metastasectomy combined with adjuvant immunotherapy did not result in a significantly higher overall survival rate as compared with metastasectomy alone. Our findings raise the question of "Is there a role of adjuvant immunotherapy after complete metastasectomy in patients with metastatic renal cell carcinoma?"

Gastrin-releasing peptide receptor as a molecular target in experimental anticancer therapy

Over the last two decades, several lines of experimental evidence have suggested that the gastrin-releasing peptide (GRP) may act as a growth factor in many types of cancer. For that reason, gastrin-releasing peptide receptor (GRPR) antagonists have been developed as anticancer candidate compounds, exhibiting impressive antitumoral activity both in vitro and in vivo in various murine and human tumors. In this article, the GRPR cell surface expression profile in human malignancies is reviewed aiming at the identification of potential tumor types for future clinical trials with GRP analogues and antagonists. In this review, we summarize the current literature regarding the GRPR status in human malignancies. Source data were obtained by searching all published material available through Medline, PubMed and relevant articles from 1971 to 2006. The data available demonstrated a high expression of GRPRs in a large spectrum of human cancers, demonstrating the potential relevance of this intracellular signaling pathway in various human tumor models. The GRPR may be an interesting target for therapeutic intervention in human malignancies, as carriers for cytotoxins, immunotoxins or radioactive compounds, being also a potential tool for tumor detection.