Definition, diagnosis and clinical management of non-obstructive kidney dysplasia: a consensus statement by the ERKNet Working Group on Kidney Malformations.

Kidney dysplasia is one of the most frequent causes of chronic kidney failure in children. While dysplasia is a histological diagnosis, the term 'kidney dysplasia' is frequently used in daily clinical life without histopathological confirmation. Clinical parameters of kidney dysplasia have not been clearly defined, leading to imprecise communication amongst healthcare professionals and patients. This lack of consensus hampers precise disease understanding and the development of specific therapies. Based on a structured literature search, we here suggest a common basis for clinical, imaging, genetic, pathological and basic science aspects of non-obstructive kidney dysplasia associated with functional kidney impairment. We propose to accept hallmark sonographic findings as surrogate parameters defining a clinical diagnosis of dysplastic kidneys. We suggest differentiated clinical follow-up plans for children with kidney dysplasia and summarize established monogenic causes for non-obstructive kidney dysplasia. Finally, we point out and discuss research gaps in the field.

Lucitanib for the Treatment of HR+/HER2- Metastatic Breast Cancer: Results from the Multicohort Phase II FINESSE Study.

PURPOSE: The FGFR1 gene is amplified in 14% of patients with HR + /HER2 - breast cancer. Efficacy and safety of lucitanib, an inhibitor of VEGFR1-3, FGFR1-3, and PDGFRα/ß, were assessed. PATIENTS AND METHODS: Patients with HR + /HER2 - metastatic breast cancer (MBC) received oral lucitanib in three centrally confirmed cohorts: (i) FGFR1 amplified, (ii) FGFR1 nonamplified, 11q13 amplified, and (iii) FGFR1 and 11q13 nonamplified. Key inclusion criteria included Eastern Cooperative Oncology Group Performance Status ≤2, ≥1 line of anticancer therapy, but ≤2 lines of chemotherapy. Primary endpoint was overall response rates (ORR) by RECIST1.1. Simon's two-stage design was used: If ≥2 patients responded among 21 patients, 20 additional patients could be enrolled in each cohort. FGFR1 copy-number variation (CNV) was determined by FISH and droplet digital PCR, whereas FGFR1 expression was determined by IHC. RESULTS: Seventy-six patients (32/18/26 in cohorts 1/2/3) from nine countries were enrolled. The prespecified primary endpoint was met in cohort 1 with ORR of 19% [95% confidence interval (CI), 9%-35%], but not in cohorts 2 and 3 with ORR of 0% (95% CI, 0%-18%) and 15% (95% CI, 6%-34%), respectively. Frequent adverse events included hypertension (87%), hypothyroidism (45%), nausea (33%), and proteinuria (32%). Exploratory biomarker analyses suggested higher ORR in patients with high FGFR1 amplification (≥4 CNV) than those without high amplification (22% vs. 9%). ORR in patients with FGFR1-high tumors (IHC, H-score ≥50) was 25% versus 8% in FGFR1-low cancers. CONCLUSIONS: Lucitanib had modest antitumor activity and significant hypertension-related toxicity in patients with HR + /HER2 - MBC. Although based on small sample sizes, exploratory biomarker analyses suggested that patients with high FGFR1 amplification or expression might derive greater benefit.

Transcriptional repression of the tyrosinase-related protein 2 gene by transforming growth factor-ß and the Kruppel-like transcription factor GLI2.

BACKGROUND: Tyrosinase-Related Protein 2 (TRP2) is an enzyme involved in melanogenesis, that also exerts proliferative, anti-apoptotic and immunogenic functions in melanoma cells. TRP2 transcription is regulated by the melanocytic master transcription factor MITF. GLI2, a transcription factor that acts downstream of Hedgehog signaling, is also a direct transcriptional target of the TGF-ß/SMAD pathway that contributes to melanoma progression and exerts transcriptional antagonistic activities against MITF. OBJECTIVES: To characterize the molecular events responsible for TGF-ß and GLI2 repression of TRP2 expression. METHODS: In silico promoter analysis, transient cell transfection experiments with 5'-end TRP2 promoter deletion constructs, chromatin immuno-precipitation, and site-directed promoter mutagenesis were used to dissect the molecular mechanisms of TRP2 gene regulation by TGF-ß and GLI2. RESULTS: We demonstrate that TGF-ß and GLI2-specific TRP2 repression involves direct mechanisms that occur in addition to MITF downregulation by TGF-ß and GLI2. We identify two functional GLI2 binding sites within the TRP2 promoter that are critical for TGF-ß and GLI2 responsiveness, one of them overlapping a CREB binding site. GLI2 and CREB competing for the same cis-element is associated with opposite transcriptional outcome. CONCLUSION: Our results further refine the understanding of how TGF-ß and GLI2 control the phenotypic plasticity of melanoma cells. In particular, we identify critical GLI2-binding cis-elements within the TRP2 promoter region that allow for its transcriptional repression independently from MITF concomitant downregulation.

In Vitro and In Vivo Activity of Lucitanib in FGFR1/2 Amplified or Mutated Cancer Models.

The fibroblast growth factor receptor (FGFR) pathway has been implicated both as an escape mechanism from anti-angiogenic therapy and as a driver oncogene in different tumor types. Lucitanib is a small molecule inhibitor of vascular endothelial growth factor (VEGF) receptors 1 to 3 (VEGFR1 to 3), platelet derived growth factor α/ß (PDGFRα/ß) and FGFR1-3 tyrosine kinases and has demonstrated activity in a phase I/II clinical study, with objective RECIST responses in breast cancer patients with FGFR1 or FGF3/4/19 gene amplification, as well as in patients anticipated to benefit from anti-angiogenic agents. We report here the in vitro and in vivo antitumor activity of lucitanib in experimental models with or without FGFR1/2 amplification or mutations. In cell assays, lucitanib potently inhibited the growth of tumor cell lines with amplified FGFR1 or mutated/amplified FGFR2. In all xenograft models studied, lucitanib demonstrated marked tumor growth inhibition due to potent inhibition of angiogenesis. Notably, in two lung cancer models with FGFR1 amplification, the antitumor efficacy was higher, suggesting that the simultaneous inhibition of VEGF and FGF receptors in FGFR1 dependent tumors can be therapeutically advantageous. Similar antitumor activity was observed in FGFR2 wild-type and amplified or mutated xenograft models. Pharmacokinetic studies showed lucitanib plasma concentrations in the micro/sub-micromolar range demonstrated drug accumulation following repeated lucitanib administration.

Crosstalk between TGF-ß and hedgehog signaling in cancer.

Hedgehog (HH) and TGF-ß signals control various aspects of embryonic development and cancer progression. While their canonical signal transduction cascades have been well characterized, there is increasing evidence that these pathways are able to exert overlapping activities that challenge efficient therapeutic targeting. We herein review the current knowledge on HH signaling and summarize the recent findings on the crosstalks between the HH and TGF-ß pathways in cancer.

Expression of microphthalmia-associated transcription factor (MITF), which is critical for melanoma progression, is inhibited by both transcription factor GLI2 and transforming growth factor-ß.

The melanocyte-specific transcription factor M-MITF is involved in numerous aspects of melanoblast lineage biology including pigmentation, survival, and migration. It plays complex roles at all stages of melanoma progression and metastasis. We established previously that GLI2, a Kruppel-like transcription factor that acts downstream of Hedgehog signaling, is a direct transcriptional target of the TGF-ß/SMAD pathway and contributes to melanoma progression, exerting antagonistic activities against M-MITF to control melanoma cell invasiveness. Herein, we dissected the molecular mechanisms underlying both TGF-ß and GLI2-driven M-MITF gene repression. Using transient cell transfection experiments with M-MITF promoter constructs, chromatin immunoprecipitation, site-directed mutagenesis, and electrophoretic mobility shift assays, we identified a GLI2 binding site within the -334/-296 region of the M-MITF promoter, critical for GLI2-driven transcriptional repression. This region is, however, not needed for inhibition of M-MITF promoter activity by TGF-ß. We determined that TGF-ß rapidly repressed protein kinase A activity, thus reducing both phospho-cAMP-response element-binding protein (CREB) levels and CREB-dependent transcription of the M-MITF promoter. Increased GLI2 binding to its cognate cis-element, associated with reduced CREB-dependent transcription, allowed maximal inhibition of the M-MITF promoter via two distinct mechanisms.

GLI2 and M-MITF transcription factors control exclusive gene expression programs and inversely regulate invasion in human melanoma cells.

We recently identified GLI2, the most active of GLI transcription factors, as a direct TGF-ß/SMAD target, whose expression in melanoma cells is associated with increased invasiveness and metastatic capacity. In this work, we provide evidence that high GLI2 expression is inversely correlated with that of the melanocyte-specific transcription factor M-microphthalmia transcription factor (M-MITF) and associated transcriptional program. GLI2-expressing cell lines were characterized by the loss of M-MITF-dependent melanocytic differentiation markers and reduced pigmentation. The balance between M-MITF and GLI2 expression did not correlate with the presence or absence of BRAF-activating mutations, but rather was controlled by two distinct pathways: the TGF-ß pathway, which favors GLI2 expression, and the protein kinase A (PKA)/cAMP pathway, which pushes the balance toward high M-MITF expression. Furthermore, overexpression and knockdown experiments demonstrated that GLI2 and M-MITF reciprocally repress each other's expression and control melanoma cell invasion in an opposite manner. These findings thus identify GLI2 as a critical transcription factor antagonizing M-MITF function to promote melanoma cell phenotypic plasticity and invasive behavior.