The Medical Treatment of Metastatic Renal Cell Cancer

Enantio- and Diastereoselective Total Synthesis of Belzutifan Enabled by Rh-Catalyzed Hydrogenation

Herein, we report a nine-step synthesis of belzutifan enabled by a novel Rh-catalyzed asymmetric hydrogenation to install the contiguous fluorinated stereocenters with high enantioselectivity. Moreover, the final ketone reduction in the synthesis proceeds with high diastereoselectivity, leading to the expedient assembly of the stereotriad. In contrast to the original 16-step synthesis, this route avoids a lengthy bromination-oxidation sequence and introduces the sulfone functionality via nucleophilic aromatic substitution, obviating the need for transition metal catalysis.

YBX1 knockdown induces renal cell carcinoma cell apoptosis via Kindlin-2

Among urological tumors, renal cell carcinoma (RCC) is the third-highest mortality rate tumor, and 20%-30% of RCC patients present with metastases at the time of diagnosis. While the treatment of RCC has been improved over the last few years, its mortality stays high. Y-box binding protein 1 (YBX1) is a well-known oncoprotein that has tumor-promoting functions. YBX1 is widely considered to be an attractive therapeutic target in cancer. To develop novel therapeutics to target YBX1, it is of great importance to understand how YBX1 is finely regulated in cancer. Our previous studies showed that YBX1 in RCC cells significantly promoted cell adhesion, migration, and invasion. However, the role of YBX1 in RCC cells apoptosis has not been reported. In this study, we investigated the effect of YBX1 on cell apoptosis and elucidated the mechanisms involved. Results showed that YBX1 regulated RCC cells apoptosis and reactive oxygen species (ROS) generation via Kindlin-2. These findings indicated that YBX1 inhibited RCC cells apoptosis and may serve as a candidate RCC prognostic marker and a potential therapeutic target. Abbreviations: RCC: Renal cell carcinoma; YBX1: Y-box binding protein 1; ROS: Reactive oxygen species; ccRCC: Clear cell renal cell carcinoma; mccRCC: Metastatic clear cell renal cell carcinoma; G3BP1: Ras-GTPase activating protein SH3 domain-binding proteins 1; SPP1: Secreted phosphoprotein 1; NF-κB: Nuclear factor kappa beta; ECM: Extracellular matrix; EMT: Epithelial-mesenchymal transition; PYCR1: Pyrroline-5-carboxylate reductase 1; MEM: Eagle's Minimum Essential Medium; DMEM: Dulbecco's modified Eagle medium; FBS: Fetal bovine serum; PCR: Polymerase chain reaction; shRNA: Short hairpin RNA; siRNA: Small interfering RNA; BSA: Bovine serum albumin; DCFH-DA: 2,7-Dichlorodihydrofluorescein diacetate; FITC: Fluorescein isothiocyanate; PI: Propidium iodide.

Targeting the ERβ/Angiopoietin-2/Tie-2 signaling-mediated angiogenesis with the FDA-approved anti-estrogen Faslodex to increase the Sunitinib sensitivity in RCC

Sunitinib has been used as the main therapy to treat the metastatic clear cell renal cell carcinoma (ccRCC) as it could function via suppressing the tumor growth and angiogenesis. Yet most ccRCC tumors may still regrow due to the development of sunitinib-resistance, and detailed mechanisms remain to be further investigated. The angiopoietin family includes angiopoietin-1 and angiopoietin-2 (ANGPT-1 and -2). It was reported that estradiol regulates expression of ANGPT-1, but not ANGPT-2, through estrogen receptor α (ERα) in an experimental stroke model. To date, there is no finding to link the E2/ER signal on regulating ANGPT-2. Our study is the first to explore (i) how estrogen receptor β (ERβ) can up-regulate ANGPT-2 in RCC cells, and (ii) how ERβ-increased ANGPT-2 can promote the HUVEC tube formation and reduce sunitinib sensitivity. Mechanistic studies revealed that ERβ could function via transcriptional regulation of the cytokine ANGPT-2 in the ccRCC cells. We found the up-regulated ANGPT-2 of RCC cells could then increase the Tie-2 phosphorylation to promote the angiogenesis and increase sunitinib treatment resistance of endothelial cells. In addition to the endothelial cell tube formation and aortic ring assay, preclinical studies with a mouse RCC model also confirmed the finding. Targeting this newly identified ERβ/ANGPT-2/Tie-2 signaling pathway with the FDA-approved anti-estrogen, Faslodex, may help in the development of a novel combined therapy with sunitinib to better suppress the ccRCC progression.

Targeting newly identified ERβ/TGF-β1/SMAD3 signals with the FDA-approved anti-estrogen Faslodex or an ERβ selective antagonist in renal cell carcinoma

Renal cell carcinoma (RCC) has the third highest mortality rate among urological tumors, and 20–30% of RCC patients present with metastatic RCC at the time of diagnosis. Although recent studies have indicated that estrogen receptor β (ERβ) could play promoting roles in RCC progression, the detailed mechanisms remain to be clarified. In the present study, we found that expression of ERβ, but not ERα, increases with tumor stage and grade, and also observed that modification of ERβ signals using estrogens/anti‐estrogens, shRNA knockdown of ERβ and overexpression of ERβ using ectopic cDNA affects RCC cell proliferation, migration and invasion. Mechanism analysis revealed that ERβ can promote RCC cell invasion via an increase in transforming growth factor β1 (TGF‐β1)/SMAD3 signals, and interrupting TGF‐β1/SMAD3 signals with a TGFβR1 inhibitor can reverse/block ERβ‐increased RCC cell migration. Importantly, preclinical analyses using in vivo mouse models of RCC revealed that targeting of this newly identified ERβ/TGF‐β1/SMAD3 pathway with either the FDA‐approved anti‐estrogen ICI182,780 (Faslodex) or a selective ERβ antagonist 4‐[2‐phenyl‐5,7 bis(trifluoromethyl)pyrazolo[1,5‐a]pyrimidin‐3‐yl]phenol can significantly reduce RCC tumor growth and invasion, which may be suitable as the basis for novel therapies to more effectively suppress metastatic RCC.

Assessment of the pathologic inclusion criteria from contemporary adjuvant clinical trials for predicting disease progression after nephrectomy for renal cell carcinoma

BACKGROUND

The objective of this study was to evaluate the accuracy of the pathologic inclusion criteria from all contemporary adjuvant trials in predicting disease progression (DP) for renal cell carcinoma (RCC).

METHODS

A retrospective review was conducted on 1363 patients treated surgically for M0 RCC at the Mayo Clinic (Rochester, MN), from 1990 to 2001. Clinicopathologic features were reviewed to determine eligibility for the following trials: ARISER, ASSURE, EVEREST, PROTECT, SORCE, and S-TRAC. DP was defined as local recurrence or distant metastasis after surgery. The ability of each trial's inclusion criteria to accurately predict DP was evaluated by the c (concordance) index.

RESULTS

From the Mayo Clinic cohort, we determined that 41%, 45%, 45%, 33%, 47%, and 23% of the patients would have been eligible for the ARISER, ASSURE, EVEREST, PROTECT, SORCE, and S-TRAC clinical trials, respectively. Overall, 23% of all patients experienced DP (n = 317). Among eligible patients, 53%, 44%, 44%, 57%, 43%, and 59% developed DP during follow-up and 10%, 6%, 6%, 13%, 6%, and 18% went onto DP while not being eligible for the ARISER, ASSURE, EVEREST, PROTECT, SORCE, and S-TRAC trials, respectively. The c index of each trial to accurately predict DP from the pathologic inclusion criteria of ARISER, ASSURE, EVEREST, PROTECT, SORCE, and S-TRAC were 0.751, 0.751, 0.751, 0.742, 0.745, and 0.691, respectively.

CONCLUSIONS

Although the pathologic inclusion criteria of contemporary adjuvant trials have notable differences, all 6 adjuvant trials demonstrated high predictive accuracy of DP. Overall, 43% to 59% of patients included for the adjuvant trials would develop DP, whereas 6% to 18% of patients excluded from the trials would develop DP during follow-up.

[Surgical treatment for renal cancer metastases]

Complete removal of metastatic lesions can contribute to improve clinical prognosis of renal cancer. Nowadays, it is accepted that surgical extirpation of solitary metastases for patients with renal cancer is the only potential for long-term survival. Provided that the metastases could be technical and functionally resected. This review addresses the current evidence about resecable renal cancer metastases at lung, liver, bone, kidney and other organs. The criteria to consider a patient as candidate for resection of metastases are: control of primary tumor, surgical extirpation feasibility and lack of systemic disease. In patients with synchronous metastases, the surgical extirpation should be performed at the same time than nephrectomy. The clinical prognosis is worse when metastases are asynchronous. After the introduction of novel anti-angiogenic agents, surgery is also justified in patients with good responses. Although, this approach remains in the field of investigation.

Urinary collecting system invasion in renal cell carcinoma: incidence and long-term prognosis

OBJECTIVES

Current data on the prognostic impact of urinary collecting system (UCS) invasion by renal cell carcinoma (RCC) are highly conflicting. The aim of the present study was to assess incidence and long-term prognosis of RCC patients with and without UCS involvement.

METHODS

We evaluated 780 patients who had undergone renal surgery between 1990 and 2005. The mean follow-up was 5.44 years.

RESULTS

Sixty-seven patients (8.6%) demonstrated UCS invasion. These patients had a significant increase in the likelihood of cancer-related death (hazard ratio [HR] 1.9, 95% confidence interval: 1.4-2.7; P = 0.001). Their median 5-year tumor-specific survival rate was 61%, as opposed to 79% for patients without UCS invasion (P = 0.001). UCS invasion was significantly associated with tumor stage, grade, clinical symptoms, lymph node and visceral metastasis at diagnosis, but not with age, gender, histologic subtype or body mass index. However, by means of multivariate analysis, UCS invasion was disqualified as an individual prognostic marker for RCC.

CONCLUSION

We do not advocate the inclusion of UCS invasion into upcoming Tumor-Nodes-Metastasis staging systems. In contrast, future research should focus on the prognostic role of novel molecular tumor markers and/or specific immunological characteristics of RCC patients.

Metastatic renal cell carcinoma: recent advances and current therapeutic options

For many years immuno(chemo)therapy has been the only therapeutic option for patients with metastatic renal cell carcinoma. Few patients, however, experienced long-term disease control and toxicity was considerable. Recent advances in understanding the biology and genetics of this malignancy have led to novel-targeted therapeutic approaches. Since 2003, a multitude of new drugs have been developed and tested, with small molecule tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors and monoclonal antibodies appearing to be the most promising agents. In the following, we give a concise overview on results of current trials in metastatic renal cell carcinoma published within 2007. Moreover, we will translate these results into therapeutic options and recommendations.

Comparison of predictive accuracy of four prognostic models for nonmetastatic renal cell carcinoma after nephrectomy: a multicenter European study

BACKGROUND

The objective of the current study was to compare, in a large multicenter study, the discriminating accuracy of four prognostic models developed to predict the survival of patients undergoing nephrectomy for nonmetastatic renal cell carcinoma (RCC).

METHODS

A total of 2404 records of patients from 6 European centers were retrospectively reviewed. For each patient, prognostic scores were calculated according to four models: the Kattan model, the University of California at Los Angeles integrated staging system (UISS) model, the Yaycioglu model, and the Cindolo model. Survival curves were estimated by the Kaplan-Meier method and compared by the log-rank test. Discriminating ability was assessed by the Harrell c-index for censored data. The primary end point was overall survival (OS), and the secondary end points were cancer-specific survival (CSS) and disease recurrence-free survival (RFS).

RESULTS

At last follow-up, 541 subjects had died of any causes, with a 5-year OS rate of 80%. The 5-year CSS and RFS rates were 85% and 78%, respectively. All models discriminated well (P < 0.0001). The c-indexes for OS were 0.706 for the Kattan nomogram, 0.683 for the UISS model, and 0.589 and 0.615 for the Yaycioglu and Cindolo models, respectively. The Kattan nomogram was found to improve discrimination substantially in the UISS intermediate-risk patients.

CONCLUSIONS

The current study appears to better define the general applicability of prognostic models for predicting survival in patients with nonmetastatic RCC treated with nephrectomy. The results suggest that postoperative models discriminate substantially better than preoperative ones. The Kattan model was consistently found to be the most accurate, although the UISS model was only slightly less well performing. The Kattan model can be useful in the UISS intermediate-risk patients.

Second-line strategies for metastatic renal cell carcinoma: classics and novel approaches

OBJECTIVES

Renal cell carcinoma is an aggressive malignancy with a high propensity for both early and metachronous regional and distant metastasis. While surgical resection is the mainstay of therapy for patients with localized disease, the prognosis for patients with distant metastasis is poor with a 5-year survival rate of less than 10%. Response rates to first-line immunotherapy or immunochemotherapy range from 10-35%; responses achieved are predominantly partial remissions of short duration. Until today, there is no standard therapeutic procedure for the growing number of patients who relapse following first-line therapy and desire further active treatment.

MATERIALS AND METHODS

This article reviews classic and recent publications about second- and third-line approaches, their potential efficacy and toxicity.

RESULTS

Several novel approaches have raised well-founded hope. Especially the application of monoclonal antibodies targeting VEGF signalling as well as different receptor tyrosine kinase inhibitors have the potential to change the face of second-line treatment of patients with metastatic RCC. Both groups of agents are focused in current phase III trials, either as mono- and/or combination therapy.

CONCLUSIONS

Until today, second-line treatment of patients with metastatic RCC progressing under therapy with biological response modifiers remains an unresolved issue. The results of ongoing clinical trials evaluating novel targeted approaches can be expected with suspense.

Application of retinoids in the treatment of renal cell carcinoma–a futile effort?

The therapeutic benefit of adding retinoids such as all-trans retinoic acid (RA), 9-cis-RA or 13-cis-RA to established single-agent or combination immuno/chemotherapy regimens for the treatment of metastatic renal cell carcinoma (RCC) has been extensively investigated during the last decade. However, at present results are contradictory and their application controversial. Moreover, recent studies indicated a significantly higher incidence of toxic side-effects in patients treated with retinoids in addition to established bio/chemotherapy. This Commentary summarizes preclinical and clinical trials investigating efficacy and toxicity of retinoids in the treatment of RCC.