Assessing the Clinical Relevance of Soluble PD-1 and PD-L1: A Multi-Cohort Study Across Diverse Tumor Types and Prognostic Implications

Background/Objectives: Immune checkpoint inhibitors targeting the PD-1/PD-L1 pathway have revolutionized cancer immunotherapy, however the clinical relevance of their soluble forms (sPD-1 and sPD-L1) remains less studied. Soluble PD-1 and PD-L1 have been implicated in tumor progression, prognosis, and treatment response across various malignancies. This study aims to provide a comprehensive analysis of sPD-1 and sPD-L1 levels in serum across diverse tumor types, including rare malignancies, and to evaluate their associations with clinicopathological characteristics and prognostic significance. Methods: In this study we analyzed sPD-1 and sPD-L1 levels in serum samples from 675 cancer patients representing a range of malignancies, including ovarian cancer, breast cancer, gastric cancer, colorectal cancer, renal cell carcinoma, and bone tumors. sPD-1 and sPD-L1 concentrations were measured using ELISA. Statistical analyses were performed to evaluate associations between soluble marker concentrations and clinicopathological factors, including tumor stage, size, histological subtype, and survival outcomes. Results: Elevated sPD-L1 levels were observed in several tumor types, including ovarian cancer, renal cell carcinoma, and gastric cancer, where they were associated with features of advanced disease, such as tumor size, stage, and metastases. In contrast, sPD-1 levels showed limited associations, with significant findings solely in gastric cancer and bone tumors, where levels correlated with histological subtype and differentiation. Prognostic analyses identified sPD-L1 as a marker of poor survival outcomes in ovarian cancer and bone tumors, while sPD-1 displayed no consistent prognostic significance. Conclusions: This study identifies the potential of sPD-L1 as a biomarker for tumor progression and prognosis across multiple malignancies. In contrast, sPD-1 showed limited clinical relevance, suggesting the importance of further investigation. These findings contribute to our understanding of soluble immune checkpoint proteins and their integration into personalized oncology strategies.

Influence of genetic polymorphisms in vascular endothelial-related genes on the clinical outcome of axitinib in patients with metastatic renal cell carcinoma

OBJECTIVE

Axitinib is an oral multi-target tyrosine kinase inhibitor used for the treatment of renal cell carcinoma (RCC). Because of the severe adverse events (AEs) associated with axitinib, patients often need dose reductions or discontinue its use, highlighting the need for effective biomarkers to assess efficacy and/or AEs. The aim of this study was to investigate the relationship between single nucleotide polymorphisms (SNPs) in genes involved in the pharmacodynamic action of axitinib and clinical prognosis and AEs in metastatic RCC (mRCC) patients.

METHODS

This study included 80 mRCC patients treated with first-, second-, or third-line axitinib (5 mg orally twice daily). Clinical parameters and genetic polymorphisms were examined in 75 cases (53 males and 22 females). We assessed three SNPs in each of three candidate genes namely, angiotensin-converting enzyme (ACE), nitric oxide synthase 3 (NOS3), and angiotensin II receptor type 1 (AT1R), all of which are involved in axitinib effects on vascular endothelial function.

RESULTS

Axitinib-treated patients carrying the ACE deletion allele suffered more frequently from hand-foot syndrome and a deterioration in kidney function (p  = .045 and p =  0.005, respectively) whereas those carrying the NOS3 G allele suffered more frequently from proteinuria and multiple AEs (p  = .025 and p =  0.036, respectively).

CONCLUSIONS

Our study found that the ACE deletion allele and the NOS3 G allele are associated with increased AEs.

Comprehensive analysis reveals dual biological function roles of EpCAM in kidney renal clear cell carcinoma

Background

Epithelial cell adhesion molecule (EpCAM), a well-established marker for circulating tumor cells, plays a crucial role in the complex process of cancer metastasis. The primary objective of this investigation is to study EpCAM expression in pan-cancer and elucidate its significance in the context of kidney renal clear cell carcinoma (KIRC).

Methods

Data obtained from the public database was harnessed for the comprehensive assessment of the EpCAM expression levels and prognostic and clinicopathological correlations in thirty-three types of cancer. EpCAM was validated in our own KIRC sequencing and immunohistochemical cohorts. Subsequently, an in-depth exploration was conducted to scrutinize the interrelationship between EpCAM and various facets, including immune cells, immune checkpoints, and chemotherapy drugs. We employed Cox regression analysis to identify prognostic immunomodulators associated with EpCAM, which were subsequently utilized in the development of a prognostic model. The model was validated in our own clinical cohort and public datasets, and compared with 137 published models. The role of EpCAM in KIRC was explored by biological function experiments in vitro.

Results

While EpCAM exhibited pronounced overexpression across a wide spectrum of cancer types, a notable reduction was observed in KIRC tissues. As grade increased, EpCAM expression decreased. EpCAM expression decreased in patients without metastasis. EpCAM mRNA and protein levels were used as independent, favorable prognostic factors in patients with KIRC in our own cohort. The expression of EpCAM exhibited strong associations with immune-related pathways, demonstrating an inverse correlation with the majority of immune cell types. Immune checkpoint inhibitors exert better therapeutic effects on patients with low EpCAM expression. In addition, EpCAM can be used as a drug resistance indicator and guide the clinical medication of patients with KIRC. A robust model, which had good predictive accuracy and applicability, showed significant superiority over other models. Importantly, EpCAM played the dual roles of promoting proliferation and resisting metastasis in KIRC.

Conclusion

In the context of KIRC, EpCAM assumes a surprising dual role, where it not only facilitates cell proliferation but also exerts resistance against the metastatic process. EpCAM serves as a standalone prognostic marker for patients with KIRC, and related models can also effectively predict prognosis. These discoveries offer novel perspectives on the functional significance of EpCAM in the context of KIRC.

Inhibiting stanniocalcin 2 reduces sunitinib resistance of Caki-1 renal cancer cells under hypoxia condition

Background

Our previous study has suggested that blocking stanniocalcin 2 (STC2) could reduce sunitinib resistance in clear cell renal cell carcinoma (ccRCC) under normoxia. The hypoxia is a particularly important environment for RCC occurrence and development, as well as sunitinib resistance. The authors proposed that STC2 also plays important roles in RCC sunitinib resistance under hypoxia conditions.

Methods

The ccRCC Caki-1 cells were treated within the hypoxia conditions. Real-time quantitative PCR and Western blotting were applied to detect the STC2 expression in ccRCC Caki-1 cells. STC2-neutralizing antibodies, STC2 siRNA, and the recombinant human STC2 (rhSTC2) were used to identify targeting regulation on STC2 in modulating sunitinib resistance, proliferation, epithelial-mesenchymal transition (EMT), migration, and invasion. In addition, autophagy flux and the lysosomal acidic environment were investigated by Western blotting and fluorescence staining, and the accumulation of sunitinib in cells was observed with the addition of STC2-neutralizing antibodies and autophagy modulators.

Results

Under hypoxia conditions, sunitinib disrupted the lysosomal acidic environment and accumulated in Caki-1 cells. Hypoxia-induced the STC2 mRNA and protein levels in Caki-1 cells. STC2-neutralizing antibodies and STC2 siRNA effectively aggravated sunitinib-reduced cell viability and proliferation, which were reversed by rhSTC2. In addition, sunitinib promoted EMT, migration, and invasion, which were reduced by STC2-neutralizing antibodies.

Conclusion

Inhibiting STC2 could reduce the sunitinib resistance of ccRCC cells under hypoxia conditions.

Predictive genomic biomarkers of therapeutic effects in renal cell carcinoma

BACKGROUND

In recent years, there have been great improvements in the therapy of renal cell carcinoma. Nevertheless, the therapeutic effect varies significantly from person to person. To discern the effective treatment for different populations, predictive molecular biomarkers in response to target, immunological, and combined therapies are widely studied.

CONCLUSION

This review summarized those studies from three perspectives (SNPs, mutation, and expression level) and listed the relationship between biomarkers and therapeutic effect, highlighting the great potential of predictive molecular biomarkers in metastatic RCC therapy. However, due to a series of reasons, most of these findings require further validation.

Insulin receptor expression to predict resistance to axitinib and elucidation of the underlying molecular mechanism in metastatic renal cell carcinoma

BACKGROUND

The study aimed to examine the significance of insulin receptor (INSR) expression in predicting resistance to axitinib in clear cell renal cell carcinoma (ccRCC).

METHODS

Clinicopathological data were collected from 36 consecutive patients with metastatic RCC who received axitinib. Thirty-three primary tumours were obtained for immunohistochemistry. Patient-derived xenograft (PDX) models were created by transplanting primary tumours into immunodeficient mice, establishing axitinib-resistant PDX models. RCC cell lines were co-cultured with human renal glomerular endothelial cells (HGECs) treated with siRNA of INSR (HGEC-siINSR). Gene expression alteration was analysed using microarray.

RESULTS

The patients with low INSR expression who received axitinib had a poorer outcome. Multivariate analysis showed that INSR expression was the independent predictor of progression-free survival. INSR expression decreased in axitinib-resistant PDX tumours. RCC cell lines showed upregulated interferon responses and highly increased interferon-β levels by co-culturing with HGEC-siINSR. HGECs showed decreased INSR and increased interferon-β after axitinib administration. RCC cell lines co-cultured with HGEC-siINSR showed high programmed death-ligand 1 (PD-L1) expression, which increased after interferon-β administration.

CONCLUSIONS

Decreased INSR in RCC could be a biomarker to predict axitinib resistance. Regarding the resistant mechanism, vascular endothelial cells with decreased INSR in RCC may secrete interferon-β and induce PD-L1.

Discovery of Novel Drug-like PHGDH Inhibitors to Disrupt Serine Biosynthesis for Cancer Therapy

Being the rate-limiting enzyme within the serine biosynthesis pathway, phosphoglycerate dehydrogenase (PHGDH) is abnormally overexpressed in numerous malignant tumor cells and is a promising target for cancer treatment. Here, we report a series of novel PHGDH inhibitors using a focused compound screening and structural optimization approach. The lead compound D8 displayed good enzymatic inhibitory activity (IC₅₀ = 2.8 ± 0.1 μM), high binding affinity (K_d = 2.33 μM), and sensitivity to the cell lines with the PHGDH gene amplification or overexpression. Furthermore, D8 was proven to restrict the de novo serine synthesis from glucose within MDA-MB-468 cells. X-ray crystallographic analysis, molecular dynamics simulations, and mutagenesis experiments on PHGDH revealed the binding site at D175 inside the NAD⁺-binding pocket. Finally, D8 exhibited excellent in vivo pharmacokinetic properties (F = 82.0%) and exerted evident antitumor efficacy in the PC9 xenograft mouse model.

Renal Carcinoma and Angiogenesis: Therapeutic Target and Biomarkers of Response in Current Therapies

Due to the aberrant hypervascularization and the high immune infiltration of renal tumours, current therapeutic regimens of renal cell carcinoma (RCC) target angiogenic or immunosuppressive pathways or both. Tumour angiogenesis plays an essential role in tumour growth and immunosuppression. Indeed, the aberrant vasculature promotes hypoxia and can also exert immunosuppressive functions. In addition, pro-angiogenic factors, including VEGF-A, have an immunosuppressive action on immune cells. Despite the progress of treatments in RCC, there are still non responders or acquired resistance. Currently, no biomarkers are used in clinical practice to guide the choice between the different available treatments. Considering the role of angiogenesis in RCC, angiogenesis-related markers are interesting candidates. They have been studied in the response to antiangiogenic drugs (AA) and show interest in predicting the response. They have been less studied in immunotherapy alone or combined with AA. In this review, we will discuss the role of angiogenesis in tumour growth and immune escape and the place of angiogenesis-targeted biomarkers to predict response to current therapies in RCC.

68Ga-PSMA-11 PET/CT Parameter Correlates with Pathological VEGFR-2/PDGFR-β Expression in Renal Cell Carcinoma Patients

BACKGROUND

Response prediction is necessary for renal cell carcinoma (RCC) tumors. We aim to evaluate parameters derived from ⁶⁸ Ga-PSMA-11 PET/CT images for prediction of pathological VEGFR-2/PDGFR-β expression of primary RCC tumors.

METHODS

Forty-eight RCC patients were retrospectively enrolled with preoperative ⁶⁸ Ga-PSMA-11 PET/CT scan and surgical specimen. Radiological parameters including tumor diameter, mean CT value, and maximal standard uptake value (SUV_max) were derived from PET/CT images and pathological VEGFR-2/PDGFR-β/PSMA expression were identified with immunohistochemistry. Mann-Whitney U test was performed for continuous variables and the chi-square test for categorical variables. ROC was used for determining the effectiveness of preoperative parameters in differentiating VEGFR-2/PDGFR-β expression. Univariate and multivariate logistic regression analyses were performed for significant parameters to predict VEGFR-2 & PDGFR-β co-expression.

RESULTS

Of the 48 tumors, 25 (52.1%) harbored positive VEGFR-2 expression, 28 (58.3%) harbored positive PDGFR-β expression, and 24 (50%) were both VEGFR-2 positive and PDGFR-β positive. SUV_max significantly differed by subgroups of VEGFR-2/PDGFR-β expression (both P < 0.001). SUV_max demonstrated superior performance for differentiating VEGFR-2 & PDGFR-β co-expression (positive vs. negative), with area under the curve 0.87 (95% CI 0.78-0.96, P < 0.001), sensitivity 93% and specificity 78%. Moreover, SUV_max was identified as the significant predictor for VEGFR-2 & PDGFR-β co-expression (odds ratio 4.01, 95% CI 1.99-8.08, P < 0.001). Concordant with radiological findings with ⁶⁸ Ga-PSMA-11 PET/CT, pathological PSMA staining intensity was significantly higher in both VEGFR-2-positive tumor and PDGFR-β-positive tumor (P = 0.009 and P < 0.001, respectively).

CONCLUSION

⁶⁸ Ga-PSMA-11 PET/CT could effectively identify pathological VEGFR-2/PDGFR-β expression of primary RCC tumors, which may help with selection of mRCC patients suitable for TKIs treatment.

Hyperprogressive disease in patients with advanced renal cell carcinoma: a new pattern of post-treatment cancer behavior

Renal cell carcinoma (RCC) is among the most common cancers of the genitourinary system. Once RCC has progressed to a high tumor stage, surgery is no longer the optimal option, and treatment with drugs is more suitable. However, a proportion of patients with advanced RCC (aRCC) experience accelerated progression following targeted therapy or immunotherapy, a condition known as hyperprogressive disease (HPD). There is a growing body of literature that recognizes the importance of HPD. In the present review, thousands of studies that describe a variety of treatments for aRCC were identified in PubMed, Web of Science, and Cochrane Library and analyzed to establish the severity of clinical outcomes. Therefore, we managed to perform a review related to HPD of aRCC in these databases. It was found that 7~74% of patients advanced into progressive disease, 0~45% of patients died during post-treatment assessment, possibly due to fatal HPD. However, risk factors, mechanisms, and predictive factors are still not entirely clear. It is suggested that combination therapies might play a pivotal role in preventing HPD. Additional light needs to be shed on customization of therapies for aRCC after more data is collected and analyzed for HPD.

Putative N-glycoprotein markers of MCF-7/ADR cancer stem cells from N-glycoproteomics characterization of the whole cell lysate

Breast cancer is one of the most malignant diseases among females. N-glycoproteomics studies have shown that N-glycosylation alteration of tumor cells is the key player of cancer progression, multidrug resistance (MDR) and high mortality. Cancer stem cells (CSCs) have the remarkable potential of self-renewing and differentiation which leads to drug resistance and metastasis. To investigate the differentially expressed N-glycosylation in adriamycin-resistant breast cancer stem cells MCF-7/ADR CSCs (relative to MCF-7 CSCs) and find the putative biomarkers, 1:1 paired ZIC-HILIC-enriched and stable isotopic diethyl labelled (SIDE) intact N-glycopeptides from MCF-7/ADR CSCs and MCF-7 CSCs were analyzed with C18-RPLC-ESI-MS/MS (HCD with stepped NCE); differentially expressed intact N-glycopeptides (DEGPs) were identified and quantified via search engine GPSeeker. With control of spectrum-level FDR≤1%, 5515 intact N-glycopeptides were identified (1737 N-glycosites, 1705 peptide backbones and 1516 intact N-glycoproteins; 181 putative N-glycan linkages and 68 monosaccharide compositions). Among 5515 intact N-glycopeptide IDs, 3864 were identified with glycoform score≥1, i.e., one or more structure-diagnostic fragment ions were observed to distinguish sequence isomers. With the three technical replicates and the criteria of fold change≥1.5 and p value<0.05, 380 DEGPs (corresponding to 153 intact N-glycoproteins) were found along with 293 down-regulated and 87 up-regulated. For these 153 intact N-glycoproteins, the molecular functions and biological processes of were comprehensively discussed, and side-to-side comparison of differential expression results with other method were also made.

A retrospective overview of PHGDH and its inhibitors for regulating cancer metabolism

Emerging evidence suggests that cancer metabolism is closely associated to the serine biosynthesis pathway (SSP), in which glycolytic intermediate 3-phosphoglycerate is converted to serine through a three-step enzymatic transformation. As the rate-limiting enzyme in the first step of SSP, phosphoglycerate dehydrogenase (PHGDH) is overexpressed in various diseases, especially in cancer. Genetic knockdown or silencing of PHGDH exhibits obvious anti-tumor response both in vitro and in vivo, demonstrating that PHGDH is a promising drug target for cancer therapy. So far, several types of PHGDH inhibitors have been identified as a significant and newly emerging option for anticancer treatment. Herein, this comprehensive review summarizes the recent achievements of PHGDH, especially its critical role in cancer and the development of PHGDH inhibitors in drug discovery.

Prolyl Hydroxylase 3 Knockdown Accelerates VHL-Mutant Kidney Cancer Growth In Vivo

Von Hippel Lindau (VHL) inactivation, which is common in clear cell renal cell carcinoma (ccRCC), leads directly to the disruption of oxygen homoeostasis. VHL works through hypoxia-inducible factors (HIFs). Within this VHL-HIF system, prolyl hydroxylases (PHDs) are the intermediary proteins that initiate the degradation of HIFs. PHD isoform 3's (PHD3) role in ccRCC growth in vivo is poorly understood. Using viral transduction, we knocked down the expression of PHD3 in the human ccRCC cell line UMRC3. Compared with control cells transduced with scrambled vector (UMRC3-SC cells), PHD3-knockdown cells (UMRC3-PHD3KD cells) showed increased cell invasion, tumor growth, and response to sunitinib. PHD3 knockdown reduced HIF2α expression and increased phosphorylated epidermal growth factor (EGFR) expression in untreated tumor models. However, following sunitinib treatment, expression of HIF2α and phosphorylated EGFR were equivalent in both PHD3 knockdown and control tumors. PHD3 knockdown changed the overall redox state of the cell as seen by the increased concentration of glutathione in PHD3 knockdown tumors relative to control tumors. UMRC3-PHD3KD cells had increased proliferation in cell culture when grown in the presence of hydrogen peroxide compared to UMRC3-SC control cells. Our findings illustrate (1) the variable effect of PHD3 on HIF2α expression, (2) an inverse relationship between PHD3 expression and tumor growth in ccRCC animal models, and (3) the role of PHD3 in maintaining the redox state of UMRC3 cells and their proliferative rate under oxidative stress.

Validation of the Correlation Between Single Nucleotide Polymorphism rs307826 in VEGFR3 and Outcome in Metastatic Clear-Cell Renal Cell Carcinoma Patients Treated with Sunitinib

BACKGROUND: Previously, we have shown a correlation between single nucleotide polymorphism (SNP) rs307826 in vascular endothelial growth factor receptor-3 (VEGFR3) and outcome in metastatic clear-cell renal cell carcinoma (m-ccRCC) patients treated with sunitinib. OBJECTIVE: We aimed to validate this finding in an independent patient series. METHODS: m-ccRCC patients receiving sunitinib as first-line targeted therapy were included in a validation cohort. Endpoints were response rate (RR), progression-free survival (PFS) and overall survival (OS). We also updated survival data of our discovery cohort as described previously. RESULTS: Eighty-four patients were included in the validation cohort. rs307826 AG/GG-carriers had a shorter PFS (8 versus 12 months, p = 0.04) and a trend towards a shorter OS (18 versus 27 months, p = 0.22) compared to AA-carriers. In the total series of 168 patients (from the discovery cohort, as described previously, and the validation cohort), rs307826 AG/GG-carriers had a poorer RR (29% versus 53%, p = 0.008), PFS (8 versus 15 months, p = 0.0002) and OS (22 versus 31 months, p = 0.004) compared to AA-carriers. rs307826 was independently associated with PFS and OS on multivariate analysis. CONCLUSION: VEGFR3 rs307826 seems to be associated with outcome on sunitinib in m-ccRCC. Its impact highlights the role of VEGFR3 in ccRCC pathogenesis and as a target of sunitinib.

Potential new therapy of Rapalink-1, a new generation mammalian target of rapamycin inhibitor, against sunitinib-resistant renal cell carcinoma

Sunitinib, a multitargeted receptor tyrosine kinase inhibitor including vascular endothelial growth factor, has been widely used as a first-line treatment against metastatic renal cell carcinoma (mRCC). However, mRCC often acquires resistance to sunitinib, rendering it difficult to treat with this agent. Recently, Rapalink-1, a drug that links rapamycin and the mTOR kinase inhibitor MLN0128, has been developed with excellent therapeutic effects against breast cancer cells carrying mTOR resistance mutations. The aim of the present study was to evaluate the in vitro and in vivo therapeutic efficacy of Rapalink-1 against renal cell carcinoma (RCC) compared to temsirolimus, which is commonly used as a small molecule inhibitor of mTOR and is a derivative of rapamycin. In comparison with temsirolimus, Rapalink-1 showed significantly greater effects against proliferation, migration, invasion and cFolony formation in sunitinib-naïve RCC cells. Inhibition was achieved through suppression of the phosphorylation of substrates in the mTOR signal pathway, such as p70S6K, eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1) and AKT. In addition, Rapalink-1 had greater tumor suppressive effects than temsirolimus against the sunitinib-resistant 786-o cell line (SU-R 786-o), which we had previously established, as well as 3 additional SU-R cell lines established here. RNA sequencing showed that Rapalink-1 suppressed not only the mTOR signaling pathway but also a part of the MAPK signaling pathway, the ErbB signaling pathway and ABC transporters that were associated with resistance to several drugs. Our study suggests the possibility of a new treatment option for patients with RCC that is either sunitinib-sensitive or sunitinib-resistant.

MicroRNAs as potential predictors of extreme response to tyrosine kinase inhibitors in renal cell cancer

BACKGROUND

MicroRNAs play an important role as modulators of gene expression in several biological processes and are closely related to development and cell differentiation regulation. Previous works have revealed a potential predictive role for miRNAs in different tumor types. This study aims to analyze the ability of miRNAs in segregating metastatic renal cell carcinoma patients according to their responses to tyrosine kinase inhibitors (TKIs).

METHODS

Extreme responders were considered in the study and were defined as those patients that either had a long-term response (LR) (progression-free survival ˃11 months) or those that were primary refractory (PR) (progression as best response). The expression of 754 miRNAs was analyzed in tumor tissue of these 2 sets of patients.

RESULTS

In a study cohort (n = 15) 4 miRNAs were significantly associated with patient response and differentially expressed in PR vs. LR (up-regulated in PR vs. LR: miR-425-5p, down-regulated in PR vs. LR: miR-139-3p, let-7d and let-7e). Further analysis in a validation cohort (n = 36) revealed similar results.

CONCLUSION

The present data strength the potential role of miRNAs as a tool to predict treatment outcomes in patients with metastatic renal cell carcinoma treated with TKIs.

Genetic biomarkers in the VEGF pathway predicting response to anti-VEGF therapy in age-related macular degeneration

OBJECTIVE

Age-related macular degeneration (ARMD) is a leading cause of visual impairment. Intravitreal injections of anti-vascular endothelial growth factor (VEGF) are the standard treatment for wet ARMD. There is however, variability in patient responses, suggesting patient-specific factors influencing drug efficacy. We tested whether single nucleotide polymorphisms (SNPs) in genes encoding VEGF pathway members contribute to therapy response.

METHODS AND ANALYSIS

A retrospective cohort of 281 European wet ARMD patients treated with anti-VEGF was genotyped for 138 tagging SNPs in the VEGF pathway. Per patient, we collected best corrected visual acuity at baseline, after three loading injections and at 12 months. We also registered the injection number and changes in retinal morphology after three loading injections (central foveal thickness (CFT), intraretinal cysts and serous neuroepithelium detachment). Changes in CFT after 3 months were our primary outcome measure. Association of SNPs to response was assessed by binomial logistic regression. Replication was attempted by associating visual acuity changes to genotypes in an independent Japanese cohort.

RESULTS

Association with treatment response was detected for seven SNPs, including in FLT4 (rs55667289: OR=0.746, 95% CI 0.63 to 0.88, p=0.0005) and KDR (rs7691507: OR=1.056, 95% CI 1.02 to 1.10, p=0.005; and rs2305945: OR=0.963, 95% CI 0.93 to 1.00, p=0.0472). Only association with rs55667289 in FLT4 survived multiple testing correction. This SNP was unavailable for testing in the replication cohort. Of six SNPs tested for replication, one was significant although not after multiple testing correction.

CONCLUSION

Identifying genetic variants that define treatment response can help to develop individualised therapeutic approaches for wet ARMD patients and may point towards new targets in non-responders.

The prognostic value of hypoxia-inducible factor-1α in advanced cancer survivors: a meta-analysis with trial sequential analysis

Background:

Expression of hypoxia-inducible factors (HIFs) has been observed, but their prognostic role in advanced cancers remains uncertain. We conducted a meta-analysis to establish the prognostic effect of HIFs and to better guide treatment planning for advanced cancers.

Methods:

Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. Trial sequential analysis (TSA) was also performed. The clinical outcomes included overall survival (OS), disease-free survival (DFS), progression-free survival (PFS), cancer-specific survival (CSS), relapse/recurrence-free survival (RFS), and metastasis-free survival (MFS) in patients with advanced tumors according to multivariate analysis.

Results:

A total of 31 studies including 3453 cases who received chemotherapy, radiotherapy, or chemoradiotherapy were identified. Pooled analyses revealed that HIF-1α expression was correlated with worse OS (HR = 1.61, p < 0.001), DFS (HR = 1.61, p < 0.001), PFS (HR = 1.49, p = 0.01), CSS (HR = 1.65, p = 0.056), RFS (HR = 2.10, p = 0.015), or MFS (HR = 2.36, p = 0.002) in advanced cancers. HIF-1α expression was linked to shorter OS in the digestive tract, epithelial ovarian, breast, non-small cell lung, and clear cell renal cell carcinomas. Subgroup analysis by study region showed that HIF-1α expression was correlated with poor OS in Europeans and Asians, while an analysis by histologic subtypes found that HIF-1α expression was not associated with OS in squamous cell carcinoma. No relationship was found between HIF-2α expression and OS, DFS, PFS, or CSS.

Conclusions:

Targeting HIF-1α may be a useful therapeutic approach to improve survival for advanced cancer patients. Based on TSA, more randomized controlled trials are strongly suggested.

Key miRNAs and target genes played roles in the development of clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (CCRCC) is the most aggressive form of renal cell carcinoma (RCC).

OBJECTIVE

This study was aimed to identify the differentially expressed miRNAs and target genes in CCRCC.

METHODS

The miRNA and mRNA next-generation sequencing data were downloaded from The Cancer Genome Atlas (TCGA) dataset. Differential expression analysis was performed, followed by correlation analysis of miRNA-mRNA. Functional enrichment and survival analysis was also performed.

RESULTS

Seven hundred and eighty-seven patients with CCRCC from TCGA data portal were included in this study. A total of 52 differentially expressed miRNAs were identified in CCRCC. Then 2361 differentially expressed genes (DEGs) were identified. Prediction analysis and correlation analysis revealed that 89 miRNA-mRNA pairs were not only predicted by algorithms but also had a significant inverse relationship. Several differentially expressed miRNAs such as hsa-mir-501 and their target genes including AK1, SLC25A15 and PCDHGC3 had a significant prognostic value for CCRCC patients.

CONCLUSIONS

Alterations of differentially expressed miRNAs and target genes may be involved in the development of CCRCC and can be considered as the prognostic markers for CCRCC.

Biomarkers and polymorphisms in pancreatic neuroendocrine tumors treated with sunitinib

Several circulating biomarkers and single nucleotide polymorphisms (SNPs) have been correlated with efficacy and tolerability to antiangiogenic agents. These associations remain unexplored in well-differentiated, metastatic pancreatic neuroendocrine tumors treated with the multitargeted tyrosine kinase inhibitor sunitinib. We have assessed the effect on tumor response at 6 months, overall survival, progression-free survival and safety of 14 SNPs, and 6 soluble proteins. Forty-three patients were recruited. Two SNPs in the vascular endothelial growth factor receptor 3 (VEGFR-3) gene predicted lower overall survival: rs307826 with hazard ratio (HR) 3.67 (confidence interval [CI] 95%, 1.35-10.00) and rs307821 with HR 3.84 (CI 95%, 1.47-10.0). Interleukin-6 was associated with increased mortality: HR 1.06 (CI 95%, 1.01-1.12), and osteopontin was associated with shorter PFS: HR 1.087 (1.01-1.16), independently of Ki-67. Furthermore, levels of osteopontin remained higher at the end of the study in patients considered non-responders: 38.5 ng/mL vs. responders: 18.7 ng/mL, p-value=0.039. Dynamic upward variations were also observed with respect to IL-8 levels in sunitinib-refractory individuals: 28.5 pg/mL at baseline vs. 38.3 pg/mL at 3 months, p-value=0.024. In conclusion, two VEGFR-3 SNPs as well as various serum biomarkers were associated with diverse clinical outcomes in patients with well-differentiated pancreatic neuroendocrine tumors treated with sunitinib.

Evaluation of KDR rs34231037 as a predictor of sunitinib efficacy in patients with metastatic renal cell carcinoma

The identification of biomarkers able to predict clinical benefit from vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors is urgently needed. Recently, Maitland and colleagues described an association between KDR-rs34231037 and soluble VEGFR2 levels as well as pazopanib pharmacodynamics. We investigated in a well-characterized series of metastatic clear cell renal cell carcinoma patients whether rs34231037 could influence sunitinib response. Clinical data and DNA were available from an international series of 276 patients. KDR-rs34231037 association with sunitinib response, clinical benefit, and progression-free survival was analyzed using logistic and Cox regression analyses. We found that G-allele carriers were over-represented among patients with clinical benefit during sunitinib treatment compared with those refractory to the treatment (odds ratio: 3.78; 95% confidence interval: 1.02-14.06; P=0.047, multivariable analysis). In conclusion, rs34231037 variant carriers seemed to have better sunitinib response than wild-type patients. Moreover, the association with tumor size reduction suggests that this single nucleotide polymorphism might also identify patients with successful tumor downsizing under anti-VEGFR therapy.

Prognostic Role of Hypoxia-Inducible Factor-2α Tumor Cell Expression in Cancer Patients: A Meta-Analysis

Hypoxia-inducible factor-2α (HIF-2α) plays an important role in tumor progression and metastasis. A number of studies have evaluated the correlation between HIF-2α overexpression and clinical outcome in cancer patients but yielded inconsistent results. To comprehensively and quantitatively summarize the evidence on the capability of HIF-2α to predict the prognosis of cancer patients with solid tumors, a meta-analysis was carried out. Renal cell carcinoma (CC-RCC) was separately analyzed due to an alternative mechanism of regulation. Systematic literature searches were performed in PubMed and Embase databases for relevant original articles until February 2018. Forty-nine studies with 6,052 patients were included in this study. The pooled hazard ratios (HRs) with corresponding confidence intervals were calculated to assess the prognostic value of HIF-2α protein expression in tumor cells. The meta-analysis revealed strong significant negative associations between HIF-2α expression and five endpoints: overall survival [HR = 1.69, 95% confidence interval (95% CI) 1.39-2.06], disease-free survival (HR = 1.87, 95% CI 1.2-2.92), disease-specific survival (HR = 1.57, 95% CI 1.06-2.34), metastasis-free survival (HR = 2.67, 95% CI 1.32-5.38), and progression-free survival (HR = 2.18, 95% CI 1.25-3.78). Subgroup analyses revealed similar associations in the majority of tumor sites. Overall, these data demonstrate a negative prognostic role of HIF-2α in patients suffering from different types of solid tumors.

Experience with Sunitinib in metastatic renal cell carcinoma (mRCC) patients: pooled analysis from 3 Spanish observational prospective studies

BACKGROUND

A pivotal, randomized, phase III trial demonstrated a statistically significant superiority of sunitinib over interferon-α in metastatic renal cell carcinoma (mRCC) patients.

OBJECTIVE

To evaluate the effectiveness and safety of sunitinib in patients with advanced or mRCC in routine clinical practice.

METHODS

Retrospective pooled analysis of clinical data from three observational and prospective studies carried out between 2007 and 2011 in 33 Spanish hospitals. Tumor response, Progression-free survival (PFS) and overall survival (OS), and main sunitinib-related toxicities were registered.

RESULTS

224 patients were analyzed. Median PFS 10.6 months (95% CI: 9.02-12.25), median OS 21.9 months (95% CI: 17.2-26.6). Objective response rate (ORR) 43.8% (95% CI: 36.8-50.7). Median time to PR was 3.8 months (95% CI: 3.86-5.99) and to CR 8.2 months (95% CI: 4.75-9.77). The most common ≥ grade-3 AEs were asthenia/fatigue (18.7%), hand-foot syndrome (6.2%), hypertension (5.8%) and neutropenia (4.8%). Hand-foot syndrome, diarrhea and mucositis were confirmed as independent predictors for PFS and/or OS in a multivariate analysis (p < 0.05) Conclusions: Outcomes with sunitinib in daily clinical practice resemble those obtained in clinical trials. Long-term benefit with sunitinib is possible in advanced RCC patients but the appropriate management of toxicities is mandatory to enable patients to remain on treatment.

Bromodomain protein BRD4 inhibitor JQ1 regulates potential prognostic molecules in advanced renal cell carcinoma

Sunitinib is a standard molecular-targeted drug used as a first-line treatment for metastatic clear cell renal cell carcinoma (ccRCC); however, resistance to sunitinib has become a major problem in medical practice. Recently, bromodomain containing 4 (BRD4), a member of the bromodomain family proteins, was identified as a promising therapeutic target, and its inhibitor JQ1 has been shown to have inhibitory effects in various human cancers. However, the anti-cancer effects of JQ1 in ccRCC, particularly sunitinib-resistant ccRCC, are still unclear. Here, we aimed to elucidate the anti-cancer effects of JQ1 and the mechanisms underlying BRD4 inhibition in sunitinib-sensitive and -resistant ccRCCs. Analysis of The Cancer Genome Atlas (TCGA) ccRCC cohort showed that patients with high BRD4 expression had shorter overall survival than those with low expression. JQ1 treatment significantly inhibited tumor growth of sunitinib-sensitive and -resistant ccRCC cells in part through MYC regulation. Based on RNA sequencing analyses of ccRCC cells treated with JQ1 to elucidate the mechanisms other than MYC regulation, we identified several oncogenes that may be potential therapeutic targets or prognostic markers; patients with high expression of SCG5, SPOCD1, RGS19, and ARHGAP22 had poorer overall survival than those with low expression in TCGA ccRCC cohort. Chromatin immunoprecipitation assays revealed that these oncogenes may be promising BRD4 targets, particularly in sunitinib-resistant ccRCC cells. These results identified SCG5, SPOCD1, RGS19, and ARHGAP22 as potential prognostic markers and showed that BRD4 inhibition may have applications as a potential therapeutic approach in sunitinib-sensitive and -resistant ccRCC.

Pro-angiogenic gene expression is associated with better outcome on sunitinib in metastatic clear-cell renal cell carcinoma

OBJECTIVES

Clear-cell renal cell carcinomas (ccRCC) are characterized by hyper-vascularization and can respond to vascular endothelial growth factor receptor (VEGFR) inhibitors such as sunitinib. We aimed to study the predictive value of the expression of genes in the hypoxia induced factor (HIF) - vascular endothelial growth factor (VEGF) - VEGFR-pro-angiogenic pathway in metastatic ccRCC (m-ccRCC) patients treated with sunitinib and the correlation between the expression of these genes and the molecular ccrcc-classification, the expression of genes involved in the immune-suppressive microenvironment and Von Hippel-Lindau (VHL) - and Polybromo-1 (PBRM1) - mutational status.

MATERIAL AND METHODS

m-ccRCC patients treated with sunitinib as first-line targeted therapy were included. Gene expression was studied in the primary nephrectomy sample by qRT-PCR, VHL- and PBRM1-mutational status by sequencing. Response rate by RECIST, progression-free survival (PFS) and overall survival (OS) were study endpoints.

RESULTS

One hundred and four patients were included. On multivariate-analysis, HIF2A-, platelet derived growth factor receptor beta (PDGFRB)-, VEGFC-, VEGFR1- and VEGFR2-expression were correlated with PFS and HIF1A-, HIF2A-, VEGFR1- and VEGFR2-expression with OS. VEGFR2-expression showed the strongest association with outcome, being significantly correlated with all outcome parameters. HIF2A, VEGFA, VEGFR1, VEGFR2 and VEGFR3 were highly expressed in the transcriptomic ccrcc2-subtype of tumors, known to be highly sensitive to sunitinib. In the total tumor series, there was no correlation nor inverse correlation between the expression of genes involved in angiogenesis and in the immune-suppressive microenvironment. In tumors with a bi-allelic PBRM1-inactivation, HIF2A-, VEGFA-, VEGFR1- and VEGFR2-expression were higher, compared to tumors with one or two functional PBRM1-alleles.

CONCLUSIONS

Intratumoral expression of genes involved in the HIF-VEGF-VEGFR-pro-angiogenic pathway, especially VEGFR2, is associated with favorable outcome on sunitinib in m-ccRCCs. Several genes involved in this pathway are upregulated in the molecular ccrcc2-subgroup, which usually responds well to sunitinib.

Prognostic and Predictive Factors for Renal Cell Carcinoma

Metastatic renal cell carcinoma (mRCC) is an incurable malignancy, characterized by its resistance to traditional chemotherapy, radiation, and hormonal therapy. Treatment perspectives and prognosis of patients with mRCC have been significantly improved by advances in the understanding of its molecular pathogenesis, which have led to the development of targeted therapeutics. Different molecular factors derived from the tumor or the host detected in both tissue or serum could be predictive of therapeutic benefit. Some of them suggest a rational selection of patients to be treated with certain therapies, though none have been validated for routine use. This article provides an overview of both clinical and molecular factors associated with predictive or prognostic value in mRCC and emphasizes that both should be considered in parallel to provide the most appropriate, individualized treatment and achieve the best outcomes in clinical practice.

Tumour cell expression of interleukin 6 receptor α is associated with response rates in patients treated with sunitinib for metastatic clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common type of renal cell carcinoma, and anti‐angiogenic treatment is currently first line therapy for metastatic ccRCC (mccRCC). Response rates and duration of response show considerable variation, and adverse events have a major influence on patient quality of life. The need for predictive biomarkers to select responders to receptor tyrosine kinase inhibitors upfront is urgent. We investigated the predictive value of immunohistochemical biomarkers associated with angiogenesis and systemic inflammation in mccRCC. Forty‐six patients with metastatic or non‐resectable ccRCC treated with sunitinib were included. Metastatic and/or primary tumour tissue was stained by immunohistochemistry for selected markers related to angiogenesis [vascular endothelial growth factor A (VEGF‐A), VEGF receptor 2 (VEGFR2), platelet‐derived growth factor receptor β (PDGFRβ), and heat shock protein 27 (HSP27)] and immune responses [Interleukin 6 receptor α (IL6Rα), interleukin‐6 (IL6), and jagged1 (JAG1)]. The predictive potential of the candidate markers was assessed by correlations with response rates (RECIST). In addition, progression free survival (PFS) and overall survival (OS) were analysed. Low tumour cell expression of IL6Rα was significantly associated with improved response to sunitinib (Fisher's exact test, p = 0.03), but not with PFS or OS. Median/high expression of IL6Rα showed significant association with median/high expression of VEGF‐A and HSP27. Furthermore, low expression of IL6 was significantly associated with improved PFS, but not OS or response rates. High expression of IL6 was significantly associated with high expression of JAG1, VEGF‐A, VEGFR2, and PDGFRβ. Loss of tumour cell expression of IL6Rα in mccRCC patients treated with sunitinib predicts improved treatment response, and might represent a candidate predictive marker.

PHGDH as a Key Enzyme for Serine Biosynthesis in HIF2α-Targeting Therapy for Renal Cell Carcinoma

Continuous activation of hypoxia-inducible factor (HIF) is important for progression of renal cell carcinoma (RCC) and acquired resistance to antiangiogenic multikinase and mTOR inhibitors. Recently, HIF2α antagonists PT2385 and PT2399 were developed and are being evaluated in a phase I clinical trial for advanced or metastatic clear cell RCC (ccRCC). However, resistance to HIF2α antagonists would be expected to develop. In this study, we identified signals activated by HIF2α deficiency as candidate mediators of resistance to the HIF2α antagonists. We established sunitinib-resistant tumor cells in vivo and created HIF2α-deficient variants of these cells using CRISPR/Cas9 technology. Mechanistic investigations revealed that a regulator of the serine biosynthesis pathway, phosphoglycerate dehydrogenase (PHGDH), was upregulated commonly in HIF2α-deficient tumor cells along with the serine biosynthesis pathway itself. Accordingly, treatment with a PHGDH inhibitor reduced the growth of HIF2α-deficient tumor cells in vivo and in vitro by inducing apoptosis. Our findings identify the serine biosynthesis pathway as a source of candidate therapeutic targets to eradicate advanced or metastatic ccRCC resistant to HIF2α antagonists. Cancer Res; 77(22); 6321-9. ©2017 AACR.

Development of Response Classifier for Vascular Endothelial Growth Factor Receptor (VEGFR)-Tyrosine Kinase Inhibitor (TKI) in Metastatic Renal Cell Carcinoma

Vascular endothelial growth factor receptor (VEGFR)-targeted therapy improved the outcome of metastatic renal cell carcinoma (mRCC) patients. However, a prediction of the response to VEGFR-tyrosine kinase inhibitor (TKI) remains to be elucidated. We aimed to develop a classifier for VEGFR-TKI responsiveness in mRCC patients. Among 101 mRCC patients, ones with complete response, partial response, or ≥24 weeks stable disease in response to VEGFR-TKI treatment were defined as clinical benefit group, whereas patients with <24 weeks stable disease or progressive disease were classified as clinical non-benefit group. Clinicolaboratory-histopathological data, 41 gene mutations, 20 protein expression levels and 1733 miRNA expression levels were compared between clinical benefit and non-benefit groups. The classifier was built using support vector machine (SVM). Seventy-three patients were clinical benefit group, and 28 patients were clinical non-benefit group. Significantly different features between the groups were as follows: age, time from diagnosis to TKI initiation, thrombocytosis, tumor size, pT stage, ISUP grade, sarcomatoid change, necrosis, lymph node metastasis and expression of pAKT, PD-L1, PD-L2, FGFR2, pS6, PDGFRβ, HIF-1α, IL-8, CA9 and miR-421 (all, P < 0.05). A classifier including necrosis, sarcomatoid component and HIF-1α was built with 0.87 accuracy using SVM. When the classifier was checked against all patients, the apparent accuracy was 0.875 (95% CI, 0.782-0.938). The classifier can be presented as a simple decision tree for clinical use. We developed a VEGFR-TKI response classifier based on comprehensive inclusion of clinicolaboratory-histopathological, immunohistochemical, mutation and miRNA features that may help to guide appropriate treatment in mRCC patients.

Prognostic and predictive value of VHL gene alteration in renal cell carcinoma: a meta-analysis and review

The von Hippel-Lindau (VHL) gene is often inactivated in sporadic renal cell carcinoma (RCC) by mutation or promoter hypermethylation. The prognostic or predictive value of VHL gene alteration is not well established. We conducted this meta-analysis to evaluate the association between the VHL alteration and clinical outcomes in patients with RCC. We searched PUBMED, MEDLINE and EMBASE for articles including following terms in their titles, abstracts, or keywords: 'kidney or renal', 'carcinoma or cancer or neoplasm or malignancy', 'von Hippel-Lindau or VHL', 'alteration or mutation or methylation', and 'prognostic or predictive'. There were six studies fulfilling inclusion criteria and a total of 633 patients with clear cell RCC were included in the study: 244 patients who received anti-vascular endothelial growth factor (VEGF) therapy in the predictive value analysis and 419 in the prognostic value analysis. Out of 663 patients, 410 (61.8%) had VHL alteration. The meta-analysis showed no association between the VHL gene alteration and overall response rate (relative risk = 1.47 [95% CI, 0.81-2.67], P = 0.20) or progression free survival (hazard ratio = 1.02 [95% CI, 0.72-1.44], P = 0.91) in patients with RCC who received VEGF-targeted therapy. There was also no correlation between the VHL alteration and overall survival (HR = 0.80 [95% CI, 0.56-1.14], P = 0.21). In conclusion, this meta-analysis indicates that VHL gene alteration has no prognostic or predictive value in patients with clear cell RCC.

HIF pathway and c-Myc as biomarkers for response to sunitinib in metastatic clear-cell renal cell carcinoma

BACKGROUND

Clear-cell renal cell carcinoma (ccRCC) is a heterogeneous disease with a different clinical behavior and response to targeted therapies. Differences in hypoxia-inducible factor (HIF) expression have been used to classify von Hippel-Lindau gene (VHL)-deficient ccRCC tumors. c-Myc may be driving proliferation in HIF-2α-expressing tumors in a growth factor-independent manner.

OBJECTIVE

To explore the HIF-1α, HIF-2α and c-Myc baseline expression as potential predictors of sunitinib outcome as well as the effectiveness and safety with sunitinib in patients with metastatic ccRCC in routine clinical practice.

METHODS

This was an observational and prospective study involving 10 Spanish hospitals. Formalin-fixed, paraffin-embedded primary tumor samples from metastatic ccRCC patients who received sunitinib as first-line treatment were analyzed. Association between biomarker expression and sunitinib treatment outcomes was evaluated. Kaplan-Meier method was applied to measure progression-free survival (PFS) and overall survival.

RESULTS

Eighty-one patients were included: median PFS was 10.8 months (95% CI: 7.4-13.5 months), median overall survival was 21.8 months (95% CI: 14.7-29.8 months) and objective response rate was 40.7%, with 7.4% of patients achieving a complete response. Molecular marker staining was performed in the 69 available tumor samples. Significant association with lower PFS was identified for double c-Myc/HIF-2α-positive staining tumors (median 4.3 vs 11.5 months, hazard ratio =2.64, 95% CI: 1.03-6.80, P=0.036). A trend toward a lower PFS was found in positive c-Myc tumors (median 5.9 vs 10.9 months, P=0.263). HIF-1α and HIF-2α expression levels were not associated with clinical outcome.

CONCLUSION

These preliminary results suggest that predictive subgroups might be defined based on biomarkers such as c-Myc/HIF-2α. Further validation with more patients will be needed in order to confirm it. Outcomes with sunitinib in metastatic ccRCC in daily clinical practice resemble those obtained in clinical trials.

The HIF and other quandaries in VHL disease

Mutations in VHL underlie von Hippel-Lindau (VHL) disease, a hereditary cancer syndrome with several subtypes depending on the risk of developing certain combination of classic features, such as clear cell renal cell carcinoma (ccRCC), hemangioblastoma and pheochromocytoma. Although numerous potential substrates and functions of pVHL have been described over the past decade, the best-defined role of pVHL has remained as the negative regulator of the heterodimeric hypoxia-inducible factor (HIF) transcription factor via the oxygen-dependent ubiquitin-mediated degradation of HIF-α subunit. Despite the seminal discoveries that led to the molecular elucidation of the mammalian oxygen-sensing VHL-HIF axis, which have provided several rational therapies, the mechanisms underlying the complex genotype-phenotype correlation in VHL disease are unclear. This review will discuss and highlight the studies that have provided interesting insights as well as uncertainties to the underlying mechanisms governing VHL disease.

Population Modeling Integrating Pharmacokinetics, Pharmacodynamics, Pharmacogenetics, and Clinical Outcome in Patients With Sunitinib-Treated Cancer

The tyrosine kinase inhibitor sunitinib is used as first‐line therapy in patients with metastasized renal cell carcinoma (mRCC), given in fixed‐dose regimens despite its high variability in pharmacokinetics (PKs). Interindividual variability of drug exposure may be responsible for differences in response. Therefore, dosing strategies based on pharmacokinetic/pharmacodynamic (PK/PD) models may be useful to optimize treatment. Plasma concentrations of sunitinib, its active metabolite SU12662, and the soluble vascular endothelial growth factor receptors sVEGFR‐2 and sVEGFR‐3, were measured in 26 patients with mRCC within the EuroTARGET project and 21 patients with metastasized colorectal cancer (mCRC) from the C‐II‐005 study. Based on these observations, PK/PD models with potential influence of genetic predictors were developed and linked to time‐to‐event (TTE) models. Baseline sVEGFR‐2 levels were associated with clinical outcome in patients with mRCC, whereas active drug PKs seemed to be more predictive in patients with mCRC. The models provide the basis of PK/PD‐guided strategies for the individualization of anti‐angiogenic therapies.

HIF prolyl hydroxylase PHD3 regulates translational machinery and glucose metabolism in clear cell renal cell carcinoma

BACKGROUND

A key feature of clear cell renal cell carcinoma (ccRCC) is the inactivation of the von Hippel-Lindau tumour suppressor protein (pVHL) that leads to the activation of hypoxia-inducible factor (HIF) pathway also in well-oxygenated conditions. Important regulator of HIF-α, prolyl hydroxylase PHD3, is expressed in high amounts in ccRCC. Although several functions and downstream targets for PHD3 in cancer have been suggested, the role of elevated PHD3 expression in ccRCC is not clear.

METHODS

To gain insight into the functions of high PHD3 expression in ccRCC, we used PHD3 knockdown by siRNA in 786-O cells under normoxic and hypoxic conditions and performed discovery mass spectrometry (LC-MS/MS) of the purified peptide samples. The LC-MS/MS results were analysed by label-free quantification of proteome data using a peptide-level expression-change averaging procedure and subsequent gene ontology enrichment analysis.

RESULTS

Our data reveals an intriguingly widespread effect of PHD3 knockdown with 91 significantly regulated proteins. Under hypoxia, the response to PHD3 silencing was wider than under normoxia illustrated by both the number of regulated proteins and by the range of protein expression levels. The main cellular functions regulated by PHD3 expression were glucose metabolism, protein translation and messenger RNA (mRNA) processing. PHD3 silencing led to downregulation of most glycolytic enzymes from glucose transport to lactate production supported by the reduction in extracellular acidification and lactate production and increase in cellular oxygen consumption rate. Moreover, upregulation of mRNA processing-related proteins and alteration in a number of ribosomal proteins was seen as a response to PHD3 silencing. Further studies on upstream effectors of the translational machinery revealed a possible role for PHD3 in regulation of mTOR pathway signalling.

CONCLUSIONS

Our findings suggest crucial involvement of PHD3 in the maintenance of key cellular functions including glycolysis and protein synthesis in ccRCC.

Novel Angiogenesis Markers as Long-Term Prognostic Factors in Patients With Renal Cell Cancer

OBJECTIVE

To evaluate Ang-2 expression alone and in combination with expression of cell proliferation and cell survival markers (MIB-1 and Bcl-2) and angiogenesis markers (VEGFR3 and CD31), and the associations of these markers with renal cell cancer (RCC) in long-term survival.

PATIENTS AND METHODS

Our study included 224 patients with RCC who were treated before the availability of antiangiogenic agents between 1985 and 1995, at the Pirkanmaa Hospital District in Finland. All tumor samples were reclassified and reevaluated by an experienced uropathologist, and parallel tissue microarrays (TMA) were performed for immunohistochemical analysis. Kaplan-Meier's survival estimation method and Cox proportional hazards models were used for survival analysis.

RESULTS

The percentage of Ang-2 expression in the tumor area varied from 0.07 to 25.65. Ang-2 expression was significantly associated with the tumor grade and stage, as well as the MIB-1, Bcl-2, and VEGFR3 expression (P = .042, P = .019, P = .039, P = .013, and P = .005, respectively). The highest Ang-2 expression predicted better survival, P < .05. High Bcl-2 and low MIB-1 expression combined with Ang-2 expression was associated with better survival. Multivariate analysis showed poorer survival in patients with low Ang-2 or high MIB-1 expressions: HR 1.89, 95% CI 1.16 to 3.08, P = .010 and HR 2.20, 95% CI 1.36 to 3.54, P = .001, respectively.

CONCLUSIONS

Very high Ang-2 expression was associated with better survival in patients with RCC. Ang-2 expression correlated with tumor stage and grade, but it was still an independent prognostic factor in a multivariate analysis.

Target molecule expression profiles in metastatic renal cell carcinoma: Development of individual targeted therapy

The aim of this study is to analyze the level of target molecule expression in metastatic renal cell carcinoma (RCC) to determine whether there is a correlation between molecular marker expression and clinical response. Ten patients with metastatic RCC, who received receptor tyrosine kinase (RTK) targeted therapy after cytoreductive or radical nephrectomy, were included. The expression of target molecules relating to the RTK, mammalian target of rapamycin, hypoxia inducible factor, mitogen activated protein kinase, and adenosine monophosphate-activated protein kinase pathways were analyzed using real-time polymerase chain reaction and immunohistochemistry. We correlated the level of target molecule expression with clinical response, including efficacy and adverse events experience during RTK targeted therapy. All patients showed similar histological subtype and grade on pathological examination; however, the expression of RCC target molecules was very different among the patients. The expression of molecules related to the RTK pathway in RCC tissue as well as relative expression of molecules in RCC tissue compared to normal kidney tissue, were higher in patients who showed a good response to RTK targeted therapy compared to those that showed a poor response. Target molecule expression in normal kidney tissue was higher in patients who experienced high-grade adverse events than in patients who experienced low-grade events. Target molecule expression in metastatic RCC correlates with targeted therapy clinical response including efficacy and adverse events. Personalized target molecule expression profiles could be used to predict clinical response to different targeted therapies, thus helping optimization of targeted therapies for patients with metastatic RCC.

Predictive Immunohistochemical Markers Related to Drug Selection for Patients Treated with Sunitinib or Sorafenib for Metastatic Renal Cell Cancer

Targeted drug decisions in metastatic renal cell carcinoma are exclusively made on the basis of clinical criteria. We investigated whether these biomarkers (HIF-1α, HIF-2α, CAIX, VEGF, VEGFR1, VEGFR2, VEGFR3, PDGFB, PDGFRA, PDGFRB, CD31, CD44, bcl-xL, KIT, p21, CXCR4, PTEN, (CSF)-1R, RET, and FLT-3) can predictive the different effects between sunitinib and sorafenib treatments and are available to guide targeted drug selection. We enrolled all patients who underwent nephrectomy with postoperative sunitinib- or sorafenib-treatment at our institution from 2007 to 2012. Immunohistochemical approach was applied to assess the potential differential effects of immunostainings between sunitinib- and sorafenib-treated groups. We found that patients with high HIF-2α, CD31 expression showed greater relative PFS and OS benefit and patients with high CAIX expression presented greater relative OS benefit from sunitinib than from sorafenib, patients with high VEGFR1 or PDGFRB expression levels exhibited worse relative PFS benefit from sunitinib than from sorafenib. Namely high HIF-2α, CD31, and CAIX expression levels along with low VEGFR1 and PDGFRB expression levels improved the benefit of sunitinib treatment compared with sorafenib treatment. These results can identify whether patients can benefit more from sunitinib or sorafenib for drug selection guidance, eventually with precision medicine.

Expression and prognostic significance of VEGF and mTOR pathway proteins in metastatic renal cell carcinoma patients: a prognostic immunohistochemical profile for kidney cancer patients

PURPOSE

To identify prognostic molecular profiles in patients with mRCC treated with sunitinib, we performed immunohistochemical analysis for VEGF and PI3K/Akt/mTOR pathway components.

METHODS

The immunohistochemical expression of VEGF, p85α, p110γ, PTEN, p-Akt, p-mTOR, p-4E-BP1 and p-p70S6K was studied in 79 patients with mRCC who received first-line treatment with sunitinib. Expression was correlated with clinicopathological features and survival.

RESULTS

VEGF was highly expressed (median H-Score 150), while positivity for the markers of the PI3K/Akt/mTOR pathway was: p85α 43/66 (65 %), p110γ41/60 (68 %), PTEN 32/64 (50 %), p-Akt57/63 (90 %), p-mTOR48/64 (75 %), p-4E-BP1 58/64 (90 %) and p-p70S6K 60/65 (92 %). No single immunohistochemical marker was found to have prognostic significance. Instead, the combination of increased p-mTOR and low VEGF expression was adversely correlated with overall survival (OS) (3.2 vs. 16.9 months, P = 0.001).

CONCLUSION

Immunohistochemistry for VEGF and p-mTOR proteins may discriminate patients refractory to first-line sunitinib with poor prognosis. Prospective validation of our findings is needed.

Deep sequencing reveals microRNAs predictive of antiangiogenic drug response

The majority of metastatic renal cell carcinoma (RCC) patients are treated with tyrosine kinase inhibitors (TKI) in first-line treatment; however, a fraction are refractory to these antiangiogenic drugs. MicroRNAs (miRNAs) are regulatory molecules proven to be accurate biomarkers in cancer. Here, we identified miRNAs predictive of progressive disease under TKI treatment through deep sequencing of 74 metastatic clear cell RCC cases uniformly treated with these drugs. Twenty-nine miRNAs were differentially expressed in the tumors of patients who progressed under TKI therapy (P values from 6 × 10^-9 to 3 × 10^-3). Among 6 miRNAs selected for validation in an independent series, the most relevant associations corresponded to miR-1307-3p, miR-155-5p, and miR-221-3p (P = 4.6 × 10^-3, 6.5 × 10^-3, and 3.4 × 10^-2, respectively). Furthermore, a 2 miRNA-based classifier discriminated individuals with progressive disease upon TKI treatment (AUC = 0.75, 95% CI, 0.64-0.85; P = 1.3 × 10^-4) with better predictive value than clinicopathological risk factors commonly used. We also identified miRNAs significantly associated with progression-free survival and overall survival (P = 6.8 × 10^-8 and 7.8 × 10^-7 for top hits, respectively), and 7 overlapped with early progressive disease. In conclusion, this is the first miRNome comprehensive study, to our knowledge, that demonstrates a predictive value of miRNAs for TKI response and provides a new set of relevant markers that can help rationalize metastatic RCC treatment.

Change in platelet count as a prognostic indicator for response to primary tyrosine kinase inhibitor therapy in metastatic renal cell carcinoma

OBJECTIVE

To evaluate change in platelet count as an indicator of response to primary tyrosine kinase inhibitor (TKI) therapy for metastatic renal cell carcinoma (mRCC).

PATIENTS AND METHODS

We conducted a multicentre retrospective analysis of patients with mRCC undergoing primary TKI therapy from May 2005 to August 2014. Change in platelet count was defined as post-treatment platelet count after the first cycle of treatment minus the pretreatment platelet count. Response Evaluation Criteria in Solid Tumours were used to define partial response (PR), stable disease (SD) and progressive disease (PD). Analysis was conducted between subgroups with stable/increased (+ΔPlt) and decreased (-ΔPlt) counts. The primary outcome was overall survival (OS), determined using Kaplan-Meier analysis. Multivariable analysis was conducted for risk factors associated with PD.

RESULTS

A total of 115 patients with mRCC were analysed, of whom 19 (16.6%) had a +ΔPlt and 96 (83%) a -ΔPlt. More patients with a +ΔPlt had a Karnofsky score <80 (42.1 vs 14.6%; P = 0.005) and >2 metastatic sites (78.9 vs 51%; P = 0.041). More patients with +ΔPlt than with -ΔPlt had PD (89.4 vs 19.1%; P < 0.001) and more of those with -ΔPlt than with +ΔPlt had SD/PR (80.9 vs 10.6%; P < 0.001). Multivariable analysis showed that +ΔPlt (odds ratio [OR] 5.36, P < 0.001), Karnofsky score < 80 (OR 2.96, P = 0.002) and >2 metastatic sites at presentation (OR 1.87, P = 0.013) were risk factors for PD. Kaplan-Meier analysis showed a lower 5-year OS in patients with +ΔPlt than in those with -ΔPlt (23 vs 53%; P < 0.0001). +ΔPlt had a sensitivity of 48.6%, a specificity of 97.4%, a positive predictive value of 89.5% and a negative predictive value of 80.9% for PD.

CONCLUSIONS

Patients with a -ΔPlt were more likely to respond to TKI therapy and had longer OS. +ΔPlt above baseline had a high specificity for PD after primary TKI. Further investigation is required to determine the utility of ΔPlt.

Recent aspects of sunitinib therapy in patients with metastatic clear-cell renal cell carcinoma: a systematic review of the literature

Sunitinib is an orally available inhibitor of multiple tyrosine-kinase receptors approved for the treatment of advanced clear-cell renal cell carcinoma (ccRCC), a disease which has habitually had a very poor patient survival rate. Although it has become the most widely used drug for this disease, it remains not completely clear the best treatment strategy with these agent. The aim of this review is to highlight the most recent and interesting aspects of the research on treatment of advanced ccRCC with sunitinib and eventually determine alternative treatment schedule to reduce the incidence of side effects; we also wanted to review recent biomarkers able to predict response to therapy and also to point out the mechanism of acquired resistance to this drug.

A decade of pharmacogenomics research on tyrosine kinase inhibitors in metastatic renal cell cancer: a systematic review

OBJECTIVE

The individual response to targeted tyrosine kinase inhibitors (TKIs) in the treatment of metastatic renal cell cancer (mRCC) is highly variable. Outlined in this article are findings on potential biomarkers for TKI treatment outcome in mRCC and an evaluation of the status of clinical implementation.

METHODS

Articles were selected by two independent reviewers using a systematic search in five medical databases on renal cell carcinoma, TKIs, and pharmacogenetics.

RESULTS

Many researchers have focused on predictive biomarkers for treatment outcome of targeted therapies in mRCC patients. Attempts to explain differences in efficacy and toxicity of TKIs by use of genetic variants in genes related to the pharmacokinetics and pharmacodynamics of the drug have been successful.

CONCLUSION

Most findings on potential biomarkers have not been validated and therefore biomarker testing to guide choice of therapy and dose in mRCC is not yet feasible.

Combined Angiogenesis and Proliferation Markers' Expressions as Long-Term Prognostic Factors in Renal Cell Cancer

OBJECTIVES

The aim of this study was to evaluate the expression of MIB-1, BCL-2, VEGFR3, and CD31 and their associations with long-term survival in patients with renal cell cancer (RCC).

PATIENTS AND METHODS

This study consisted of 224 RCC patients who underwent radical nephrectomy from 1985 to 1995. Follow-up continued for up to over 20 years. MIB-1 and BCL-2 expression were analyzed alone, and additionally, the expression of MIB-1, BCL-2, VEGFR3, and CD31 were combined in pairs using the following groups: low/low, low/high, high/low, and high/high.

RESULTS

Low BCL-2 expression (hazard ratio [HR], 2.16; 95% confidence interval [CI], 1.42-3.31; P < .001 compared with high BCL-2 in univariate analysis) and high MIB-1 expression (HR, 2.05; 95% CI, 1.32-3.19; P = .001 in multivariate analysis) were found to associate for poorer survival in RCC. In multivariate analysis, the combination of high MIB-1/low BCL-2 was associated with poor survival compared with low MIB-1/high BCL-2 (HR, 3.20; 95% CI, 1.66-6.17; P = .001), and the combination of low VEGFR3/high CD31 was associated with poor survival (HR, 2.48; 95% CI, 1.29-4.78; P = .007) compared with high VEGFR3/high CD31.

CONCLUSIONS

Compared with high BCL-2 expression in combination with low or high MIB-1, VEGFR3, or CD31 expression, low BCL-2 expression in combination with low or high MIB-1, VEGFR3, or CD31 expression has poorer survival in the long-term follow-up of patients with RCC. Analysis of MIB-1, BCL-2, VEGFR3, and CD31 expression might be a useful additional marker to tailor the follow-up of RCC patients.

Prognostic Biomarkers for Response to Vascular Endothelial Growth Factor-Targeted Therapy for Renal Cell Carcinoma

Improved understanding of renal carcinoma disease biology has led to the discovery and approval of five novel therapies targeting specific molecules in the vascular endothelial growth factor (VEGF) biochemical pathway. Biomarker studies attempting to predict response to VEGF-targeted therapies have largely focused on circulating proteins, tissue-based molecules, and germline polymorphisms. Thus far studies have yielded conflicting results that require prospective validation; therefore no definitive biomarker has yet been integrated into the clinician's armamentarium. However, early analyses featuring genomic biomarkers have generated promising findings. This article provides an overview of available biomarkers evaluated with respect to VEGF-targeted therapies in patients with advanced renal cell carcinoma.

Prognostic Significance of Hypoxia-Inducible Factor Expression in Renal Cell Carcinoma: A PRISMA-compliant Systematic Review and Meta-Analysis

The prognostic value of hypoxia-inducible factor (HIF) in renal cell carcinoma (RCC) has been evaluated in a large number of studies, but the reports were inconsistent and remained inconclusive. Therefore, we conducted a systematic review and meta-analysis to clarify the significance of HIF expression in RCC prognosis. PubMed, Embase, Web of Science, Cochrane Library, EBSCO, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Biological Abstracts were searched for eligible studies. Hazard ratio (HR) data for overall survival (OS), cancer-specific survival (CSS), and progression-free survival (PFS) with 95% confidence interval (CI) related to the expression status of HIF-1α or HIF-2α detected by immunohistochemistry were all extracted. Data were combined using a random- or fixed-effects model based on the corresponding inter-study heterogeneity. Subgroup analyses were also performed. A total of 14 studies composed of 1258 patients for HIF-1α evaluation and 619 patients for HIF-2α evaluation were included for further analysis. When initially analyzed as a whole, the HIF-1α expression was not significantly correlated with OS (HR 1.637, 95% CI 0.898-2.985, P = 0.108), CSS (HR 1.110, 95% CI 0.595-2.069, P = 0.744), and PFS (HR 1.113, 95% CI 0.675-1.836, P = 0.674). Similarly, HIF-2α expression was not significantly correlated with CSS (HR 1.597, 95% CI 0.667-3.824, P = 0.293) and PFS (HR 0.847, 95% CI 0.566-1.266, P = 0.417). However, subgroup analyses concerning subcellular localization of HIFs revealed that the high nuclear expression of HIF-1α was significantly associated with poor OS (HR 2.014, 95% CI 1.206-3.363, P = 0.007) and the high cytoplasmic expression of HIF -2α was significantly associated with poor CSS (HR 2.356, 95% CI 1.629-3.407, P = 0.000). The increased nuclear expression of HIF-1α and cytoplasmic expression of HIF-2α indicate unfavorable prognosis in RCC patients, which may serve as biomarkers for disease management.

Impact of VEGF, VEGFR, PDGFR, HIF and ERCC1 gene polymorphisms on thymic malignancies outcome after thymectomy

We aimed to analyze genotypes of VEGF-A, VEGFR2, Flt4, PDGFRα, HIF-1α and ERCC1 and their correlation with thymic tumor risk and patient outcome. DNA of 57 consecutive patients (43 thymomas and 14 thymic carcinomas) who underwent total thymectomy at our Institution was extracted from paraffin-embedded tissue. We selected polymorphisms in the following genes:HIF1-α (rs2057482T > C, rs1951795A > C, rs2301113C > A, rs10873142C > T, rs11158358G > C, rs12434438G > A, rs11549465C > T, rs11549467G > A), VEGF-A (rs2010963G > C, rs699947A > C), VEGFR-2 (rs2305948C > T, rs1870377T > A), VEGFR-3 (rs307826T > C, rs307821C > A), PDGFR-α (rs35597368C > T) and ERCC1 (rs11615A > G). Gene polymorphisms were determined by Real-Time PCR using TaqMan assays. As compared to the general population, the allele frequency of PDGFR-α rs35597368T was significantly higher (95% vs. 87%, p = 0.036), while the frequency of alleles HIF1-α rs2057482C (78% vs. 90%), rs1951795C (69% vs. 87%), rs2301113A (70% vs. 83%), rs10873142T (70% vs. 87%), rs11158358C (75% vs. 88%), rs12434438A (67% vs. 84%) were significantly lower. VEGFR-3 rs307821C frequency was significantly higher in thymomas vs. thymic carcinomas (79% vs. 72%, p = 0.0371). The following factors were significantly correlated with a longer overall survival: VEGFR-3 rs307826C, VEGFR-2 rs1870377A, PDGFR-α rs35597368T/C, HIF1-α rs2301113C, rs2057482C/T, rs1951795C, rs11158358G/C and rs10873142T/C, ERCC1 rs11615A (p < 0.05). Our results suggest, for the first time, that PDGFR-α, HIF-1α and VEGFR-3 SNPs are associated with thymic cancer risk and survival.

Predictive molecular biomarkers to guide clinical decision making in kidney cancer: current progress and future challenges

Although the past decade has seen a surfeit of new targeted therapies for renal cell carcinoma (RCC), no predictive molecular biomarker is currently used in routine clinical practice to guide personalized therapy as a companion diagnostic. Many putative biomarkers have been suggested, but none have undergone rigorous validation. There have been considerable advances in the biological understanding of RCC in recent years, with the development of accompanying molecular diagnostics that with additional validation, may be helpful for routine clinical decision making. In this review, we summarize the current understanding of predictive biomarkers in RCC management and also highlight upcoming developments of interest in biomarker research for personalizing RCC diagnostics and therapeutics.

In vivo evaluation of battery-operated light-emitting diode-based photodynamic therapy efficacy using tumor volume and biomarker expression as endpoints

In view of the increase in cancer-related mortality rates in low- to middle-income countries (LMIC), there is an urgent need to develop economical therapies that can be utilized at minimal infrastructure institutions. Photodynamic therapy (PDT), a photochemistry-based treatment modality, offers such a possibility provided that low-cost light sources and photosensitizers are available. In this proof-of-principle study, we focus on adapting the PDT light source to a low-resource setting and compare an inexpensive, portable, battery-powered light-emitting diode (LED) light source with a standard, high-cost laser source. The comparison studies were performed in vivo in a xenograft murine model of human squamous cell carcinoma subjected to 5-aminolevulinic acid-induced protoporphyrin IX PDT. We observed virtually identical control of the tumor burden by both the LED source and the standard laser source. Further insights into the biological response were evaluated by biomarker analysis of necrosis, microvessel density, and hypoxia [carbonic anhydrase IX (CAIX) expression] among groups of control, LED-PDT, and laser-PDT treated mice. There is no significant difference in the percent necrotic volume and CAIX expression in tumors that were treated with the two different light sources. These encouraging preliminary results merit further investigations in orthotopic animal models of cancers prevalent in LMICs.