Combination therapy in metastatic renal cell cancer

Mechanistic Target of Rapamycin Inhibitors in Renal Cell Carcinoma: Potential, Limitations, and Perspectives

Several elements highlight the importance of the mechanistic target of rapamycin (mTOR) in the biology of renal cell carcinoma (RCC). mTOR signaling pathway is indeed frequently activated in RCC, inducing cancer cell proliferation and survival. In addition, mTOR promotes tumor angiogenesis and regulates the expression of hypoxia-inducible factors that play an important role in a subset of RCC. Despite mTOR protumorigenic effects, mTOR inhibitors have failed to provide long-lasting anticancer benefits in RCC patients, highlighting the need to readdress their role in the treatment of RCC. This review aims to present the rationale and limitations of targeting mTOR in RCC. Future roles of mTOR inhibitors in the treatment of RCC are also discussed, in particular in the context of immunotherapies.

C-Reactive Protein Levels and Survival Following Cytoreductive Nephrectomy in 118 Patients with Metastatic Renal Cell Carcinoma Treated with Sunitinib: A Retrospective Study

Background

This study aimed to evaluate the factors associated with a survival benefit for patients with metastatic renal cell carcinoma (mRCC) treated with sunitinib, with and without cytoreductive nephrectomy (CN).

Material/Methods

This retrospective clinical study included 118 patients with mRCC who were treated with CN and sunitinib (CN-sunitinib) (N=70) and with sunitinib-alone (N=48). Categorical clinicopathological variables were compared with hypothesis tests using contingency tables and a chi-squared test. Independent indicators for progression-free survival (PFS) and overall survival (OS) were analyzed with univariate and multivariate Cox regression models. The Kaplan-Meier method and log-rank test were used to evaluate patient survival.

Results

The median PFS and OS for the 118 patients were 8.38 and 15.48 months, respectively. There were no significant differences between the CN-sunitinib group and the sunitinib-alone group for either PFS (7.2 months vs. 11.6 months; P=0.525) or OS (16.7 months vs. 15.2 months; P=0.839). Stratification of patients based on clinicopathological characteristics showed that CN was significantly associated with reduced PFS and OS for patients with lymph node metastasis (PFS, P<0.001; OS, P<0.001) and high International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk scores (PFS, P=0.003; OS, P=0.011). However, CN was associated with a significant survival benefit for patients with low levels of serum C-reactive protein (CRP<10 mg/L) (PFS, P=0.026; OS, P=0.007).

Conclusions

Sunitinib-alone without CN improved the survival of patients with mRCC who had high IMDC risk scores or lymph node metastasis. CN and sunitinib resulted in significantly improved survival in patients with low serum CRP.

Peglated-H1/pHGFK1 nanoparticles enhance anti-tumor effects of sorafenib by inhibition of drug-induced autophagy and stemness in renal cell carcinoma

Background

Tumor targeting small molecular inhibitors are the most popular treatments for many malignant diseases, including cancer. However, the lower clinical response and drug resistance still limit their clinical efficacies. HGFK1, the first kringle domain of hepatocyte growth factor, has been defined as a potent anti-angiogenic factor. Here, we aimed to develop and identify novel nanoparticles—PH1/pHGFK1 as potential therapeutic agents for the treatment of renal cell carcinoma (RCC).

Methods

We produced a novel cationic polymer—PH1 and investigated the anti-tumor activity of PH1/pHGFK1 nanoparticle alone and its combination therapy with sorafenib in RCC cell line xenografted mice model. Then, we figured out its molecular mechanisms in human RCC cell lines in vitro.

Results

We firstly demonstrated that intravenous injection of PH1/pHGFK1 nanoparticles significantly inhibited tumor growth and prolonged the survival time of tumor-bearing mice, as well as synergistically enhanced anti-tumor activities of sorafenib. Furthermore, we elucidated that recombinant HGFK1 improved sorafenib-induced cell apoptosis and arrested cell cycle. In addition, HGFK1 could also decrease sorafenib-induced autophagy and stemness via blockading NF-κB signaling pathway in RCC both in vitro and in vivo.

Conclusions

HGFK1 could inhibit tumor growth, synergistically enhance anti-tumor activities of sorafenib and reverse its drug resistance evolution in RCC. Our results provide rational basis for clinical application of sorafenib and HGFK1 combination therapy in RCC patients.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1348-z) contains supplementary material, which is available to authorized users.

miRNAs as potential regulators of mTOR pathway in renal cell carcinoma

Renal cell carcinoma (RCC) is the most commonly occurring solid cancer of the adult kidney with the majority of RCC cases being detected accidentally. The most aggressive subtype is clear cell RCC (ccRCC). miRNAs, a family of small noncoding RNAs regulating gene expression have been identified as key biological modulators. The von Hippel-Lindau pathway is one of the signaling pathways involved in the pathophysiology of ccRCC. Another oncogenic mechanism involves the activation of PI3K/AKT/mTOR signaling and serves as a central regulator of cell metabolism, proliferation and survival. Several studies have described the involvement of miRNA dysregulation in the pathogenesis and progression of ccRCC. These molecules can be considered as potential diagnostic and prognostic biomarkers, allowing response to therapy to be monitored.

Pazopanib in Metastatic Renal Cancer: A "Real-World" Experience at National Cancer Institute "Fondazione G. Pascale"

Pazopanib is an oral angiogenesis inhibitor, currently approved for treatment of metastatic renal cell carcinoma (mRCC) and soft tissue sarcoma. The present study analyzed the outcomes of pazopanib in first-line treatment of mRCC, in a single Italian cancer center. In the light of the retrospective, observational nature and the unselected population, our experience can be defined a "real-world" study. The medical records of 38 mRCC patients treated with front-line pazopanib were retrospectively reviewed and analyzed. The progression free survival (PFS) and the overall survival (OS) were the primary endpoints, while secondary objectives included objective response rate (ORR), disease control rate (DCR), and treatment tolerability. Pazopanib achieved a median PFS (mPFS) of 12.7 months (95% CI, 6.9-18.5 months). The median OS (mOS) was 26.2 months (95% CI, 12.6-39.9 months); the observed ORR and DCR were 30.3 and 72.7%, respectively, with a median duration of response of 11 weeks. mPFS appeared not to be influenced by number of co-morbidities (< 3 vs. ≥3), gender, Fuhrman grade and age. Conversely, the ORR and the DCR positively affect the mPFS (HR = 0.05 [95% CI, 0.05-0.55], p = 0.01; HR = 0.10 [95% CI, 0.02-0.43], p = 0.002, respectively). A worse outcome was associated with a lower mPFS in patients with liver metastases (p = 0.2) and with a high tumor burden (number of metastatic sites < 6 vs. ≥6) (p = 0.08). Worst OS was observed in patients aged ≥70 years old (HR = 6.91 [95% CI, 1.49-31.91], p = 0.01). The treatment was well-tolerated: no grade 4 adverse events, nor discontinuation due to toxicities was reported. Grade 3 hypertension affected positively the OS reaching the statistical significance (HR = 0.22 [95% CI, 0.05-0.8], p = 0.03). Thyroid dysfunction (hypo and hyperthyroidism) seems to correlate with better outcome in terms of a longer mPFS (HR = 0.12 [95% CI, 0.02-0.78], p = 0.02). Our results are consistent with those reported in prospective phase III trials and the published retrospective "real world" experiences. This analysis confirms the safety and efficacy of pazopanib in first-line setting, both in frail patients with multiple co-morbidities and Karnofsky PS < 80% and in younger, healthier patients with a number of metastatic sites < 6.

A phase 1 study of buparlisib and bevacizumab in patients with metastatic renal cell carcinoma progressing on vascular endothelial growth factor-targeted therapies

BACKGROUND

The phosphatidylinositol-3 kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is dysregulated in patients with metastatic renal cell carcinoma (mRCC). Buparlisib is a pan-PI3K inhibitor with activity in advanced solid tumors. The primary objective of the current study was to determine the maximum tolerated dose (MTD) and dose-limiting toxicities of buparlisib and bevacizumab in patients with mRCC. Secondary objectives included efficacy, biomarker discovery, and additional toxicity.

METHODS

This was a standard 3 + 3 dose escalation study of buparlisib (at a dose of 60-100 mg/day) and bevacizumab (at a dose of 10 mg/kg every 2 weeks). After the MTD was defined, 15 patients were accrued to the expansion cohort.

RESULTS

Thirty-two patients were accrued (3 were treated at 60 mg/day, 21 were treated at 80 mg/day, 6 were treated at 100 mg/day, and 2 patients never received therapy). The majority of patients had clear cell histology (87%) and 50% had received ≥2 prior lines of therapy. The MTD of buparlisib was 80 mg/day and that of bevacizumab was 10 mg/kg every 2 weeks. A total of 28 patients discontinued therapy: 17 because of disease progression, 7 because of toxicity, and 4 for other reasons. Dose-limiting toxicities included rash/pruritis, elevated lipase/amylase, anorexia, and psychiatric disorders (suicidal ideation, depression, and cognitive disturbances). Of the 30 patients who received at least 1 dose, 13% achieved a partial response (95% confidence interval, 4%-31%). Two patients harboring activating PI3KA mutations achieved 42% and 16% maximal tumor shrinkage, respectively.

CONCLUSIONS

Buparlisib at a dose of 80 mg/day with bevacizumab was found to be a tolerable regimen with preliminary activity in vascular endothelial growth factor-refractory mRCC. The benefit of this combination may be of interest for future mRCC trials, possibly in a selected patient population. Cancer 2016;122:2389-2398. © 2016 American Cancer Society.

Transmembrane-Bound IL-15-Promoted Epithelial-Mesenchymal Transition in Renal Cancer Cells Requires the Src-Dependent Akt/GSK-3β/β-Catenin Pathway

Intrarenal interleukin-15 (IL-15) plays a major role controlling epithelial survival and polarization both in physiological and pathologic conditions. Herein, we confirmed that human renal cell carcinomas (RCCs) express a membrane-bound IL-15 isoform displaying an unusual molecular weight of 27 kDa. Its stimulation with soluble IL-15 receptor α chain (s-IL-15Rα) triggers epithelial-mesenchymal transition (EMT) process as shown by the down-regulation of E-cadherin and zona occludens 1 and the up-regulation of vimentin and N-cadherin and promotes the migratory and invasive properties of RCC. S-IL-15Rα treatment triggered the Src/PI3K/Akt/GSK-3β pathway and promoted β-catenin nuclei translocation. Deactivation of this pathway by using Src-specific inhibitor PP2, PI3K inhibitor LY294002, and AKT inhibitor MK2206 hampered β-catenin nuclei translocation and suppressed EMT, migration, and invasion of RCC. S-IL-15Rα treatment also enhanced Src-dependent phosphorylation of focal adhesion kinase (FAK) and extracellular signal-regulated kinase (Erk1/2). FAK knockdown significantly decreased the migration and invasion of RCC, which suggest that Src-FAK signaling was involved in s-IL-15Rα-favored migration and invasion of RCC. At the same time, inhibitors of Erk1/2 also significantly decreased the migration and invasion of RCC but could not reverse s-IL-15Rα-induced EMT. Taken together, our results reveal that Src-dependent PI3K/Akt/GSK3b/β-catenin pathway is required for s-IL-15Ra-dependent induction of EMT in RCC, while Src-FAK and Src-Erk1/2 signaling were involved in s-IL-15Rα-promoted migration and invasion properties of RCC. Our study provides a better understanding of IL-15 signaling in RCC tumor progression, which may lead to novel targeted therapies and provide some suggestions when using IL-15 in clinic.

MicroRNA-200a-3p suppresses tumor proliferation and induces apoptosis by targeting SPAG9 in renal cell carcinoma

Sperm-associated antigen 9(SPAG9), as a well-recognized oncogene protein, has a critical effect on renal cell carcinoma (RCC) progression. Our study tried to explore the mediator of miR-200a-3p, a tumor suppressing miRNA on SPAG9 expression and renal cell proliferation and apoptosis. We found the expression of miR-200a-3p was significantly lower in RCC specimens. Based on in vitro assays, we found miR-200a-3p significantly inhibit cancer cell proliferation by inducing apoptosis. In addition, our study uncovered that miR-200a-3p directly regulates oncogenic SPAG9 in 786-O and ACHN cells. Silencing of SPAG9 resulted in significantly decreased in the growth and the cell cycle of the renal cancer cell lines. Understanding of oncogenic SPAG9 regulated by miR-200a-3p might be beneficial to reveal new therapeutic targets for RCC.

Combined Radiofrequency Ablation and Double Anti-Angiogenic Protein Therapy to Increase Coagulation Efficacy: An Experimental Study in a Murine Renal Carcinoma Model

Objective

To evaluate whether suppression of tumor microvasculature by double anti-angiogenic protein (DAAP) treatment could increase the extent of radiofrequency ablation (RFA)-induced coagulation in a murine renal cell carcinoma model.

Materials and Methods

Renal cell carcinoma cell lines were implanted subcutaneously into 10 nude mice. Four mice received adenoviral DAAP treatment and 6 mice received sterile 0.9% saline solution as DAAP-untreated group. The effect of DAAP was evaluated according to the vascularity by contrast-enhanced ultrasound (CEUS) using microbubbles. Four DAAP-treated mice and 4 DAAP-untreated mice were then treated with RFA, resulting in 3 groups: no-therapy (n = 2), RFA only (n = 4), and RFA combined with DAAP treatment (n = 4). Immediately after RFA, the size of coagulation necrosis and mitochondrial enzyme activity were compared between the groups using analysis of variance (ANOVA) and post hoc test.

Results

The contrast enhancement ratio for tumor vascularization on CEUS was significantly lower in the DAAP treated group than in DAAP-untreated group (30.2 ± 9.9% vs. 77.4 ± 17.3%; p = 0.021). After RFA, the mean coagulation diameter was 0 mm for no-therapy group, 6.7 ± 0.7 mm for the RFA only group and 8.5 ± 0.4 mm for the RFA with DAAP group (ANOVA, p < 0.001). The area of viable mitochondria within the tumor was 27.9 ± 3.9% in no-therapy group, 10.3 ± 4.5% in the RFA only group, and 2.1 ± 0.7% in the RFA with DAAP group (ANOVA, p < 0.001).

Conclusion

Our results suggest the potential value of combining RFA with anti-angiogenic therapy.

Can Some Marine-Derived Fungal Metabolites Become Actual Anticancer Agents?

Marine fungi are known to produce structurally unique secondary metabolites, and more than 1000 marine fungal-derived metabolites have already been reported. Despite the absence of marine fungal-derived metabolites in the current clinical pipeline, dozens of them have been classified as potential chemotherapy candidates because of their anticancer activity. Over the last decade, several comprehensive reviews have covered the potential anticancer activity of marine fungal-derived metabolites. However, these reviews consider the term "cytotoxicity" to be synonymous with "anticancer agent", which is not actually true. Indeed, a cytotoxic compound is by definition a poisonous compound. To become a potential anticancer agent, a cytotoxic compound must at least display (i) selectivity between normal and cancer cells (ii) activity against multidrug-resistant (MDR) cancer cells; and (iii) a preferentially non-apoptotic cell death mechanism, as it is now well known that a high proportion of cancer cells that resist chemotherapy are in fact apoptosis-resistant cancer cells against which pro-apoptotic drugs have more than limited efficacy. The present review thus focuses on the cytotoxic marine fungal-derived metabolites whose ability to kill cancer cells has been reported in the literature. Particular attention is paid to the compounds that kill cancer cells through non-apoptotic cell death mechanisms.

Adjuvant therapy for renal cell carcinoma

In the past few years, several targeted therapies have been approved by the U.S. Food and Drug Administration for the treatment of advanced renal cell carcinoma. This has led to an improvement in the progression-free survival and quality of life for these patients. Nevertheless, the use of these and other therapies in the adjuvant setting has failed to demonstrate a clear benefit. Immune therapies and hormonal or targeted therapies have been studied in this indication, and there are clinical trials currently enrolling patients with high risk of relapse. This article reviews the available data and the ongoing trials exploring the role of adjuvant therapy for kidney cancer.

Sequential targeted therapy after pazopanib therapy in patients with metastatic renal cell cancer: efficacy and toxicity

INTRODUCTION/BACKGROUND

Patients with metastatic renal cell carcinoma (mRCC) in whom first-line therapies have failed might derive clinical benefit with sequential targeted agents. Limited data are available on the efficacy and toxicity of subsequent therapies after disease progression during pazopanib therapy.

PATIENTS AND METHODS

Patients with mRCC who received subsequent systemic treatment after pazopanib treatment failure were identified across 7 institutions. Pazopanib was given as first-line therapy in 28 patients and after cytokines therapy in 7 patients. Clinical outcome and toxicity analyses of 2 sequential treatment options (anti-vascular endothelial growth factor [VEGF] or mammalian target of rapamycin inhibitor [mTORi]) is presented.

RESULTS

Subsequent therapy was anti-VEGF in 22 patients and mTORi in 13. One patient who received bevacizumab and temsirolimus combination was excluded. VEGF-targeted therapies included sorafenib (n = 10), sunitinib (n = 3), bevacizumab (n = 2), cediranib (n = 4) and cabozantinib (n = 3). Patients treated with mTORi received everolimus. Median progression-free survival was 5.6 months from the start of subsequent therapy with anti-VEGF and 2.4 months with mTORi (P = .009). Overall survival (OS) was not significantly different (P = .68). Clinical benefit (including partial response and stable disease) on subsequent therapy was observed in 15 patients (64%) and 4 patients (31%) of anti-VEGF- and everolimus-treated patients, respectively (P = .021).

CONCLUSION

In this retrospective study, targeting VEGF was an effective strategy after disease progression during pazopanib treatment, although OS was not different among patients treated with VEGF or mTORi.

Targeting bone metastatic cancer: Role of the mTOR pathway

One of the great challenges of cancer medicine is to develop effective treatments for bone metastatic cancer. Most patients with advanced solid tumors will develop bone metastasis and will suffer from skeletal related events associated with this disease. Although some therapies are available to manage symptoms derived from bone metastases, an effective treatment has not been developed yet. The mammalian target of rapamycin (mTOR) pathway regulates cell growth and survival. Alterations in mTOR signaling have been associated with pathological malignancies, including bone metastatic cancer. Inhibition of mTOR signaling might therefore be a promising alternative for bone metastatic cancer management. This review summarizes the current knowledge on mTOR pathway signaling in bone tissue and provides an overview on the known effects of mTOR inhibition in bone cancer, both in in vitro and in vivo models.