Upregulation Of FGFR3 Research Articles

Abstract PO3-18-08: Rational therapeutic combination of Bromodomain and Extra-Terminal domain (BET) inhibitor and Fibroblast Growth Factor Receptor (FGFR) inhibitor for treatment of invasive lobular carcinoma

Abstract Background: Invasive lobular carcinoma (ILC) is the second most pervasive subtype after invasive ductal carcinoma (IDC), accounting for approximately 10-15% of all breast cancers. It is characterized by loss of E-cadherin expression and non-adherent tumor cells that invade the stroma in a “single-file” pattern. Women with ILC are typically diagnosed at an older age and later stage with ER-positive disease. ILC is more likely to exhibit late recurrence and metastasize to the gastrointestinal tract and urogenital tract compared with IDC. It is routinely treated with anti-endocrine therapy and chemotherapy, however, while not entirely chemo-refractory, displays a poor response to chemotherapy compared with IDC. As such, options for recurrent disease are limited and there is an urgent need to develop tailored therapy for ILC, especially for those patients that recur. The family of bromodomain and extra-terminal domain (BET) proteins, comprising BRD2/3/4/T, are epigenetic readers that bind to acetylated lysine residues on histones and recruit transcription factors to drive the expression of oncogenes. Previously. we discovered that BRD3 is a marker of poor prognosis in ILC and there is emerging evidence that BET inhibitors (iBET) are effective in diverse types of breast cancer. Here, we investigated the therapeutic potential of iBET in ILC, alone and in combination with FGFR inhibitors. Methods: IC50s for a panel of iBET using two typical ILC cell lines MDA-MB-134VI (MM134) and SUM44PE (SUM44) were determined. RNA-sequencing and Genexplain analysis was applied to reveal transcriptional networks, master regulators and potential resistance mechanisms. BRD3 and FGFR3 were knocked down using siRNA to evaluate their function in ILC cell lines. Furthermore, we utilized ILC cell-derived xenograft (CDX) models in SCID-beige mice established by mammary intraductal (MIND) implantation to evaluate the therapeutic potency of iBET alone or in combination with fibroblast growth factor receptor (FGFR) inhibitor in vivo. Results: We demonstrated that iBET significantly inhibited ILC cell growth in both 2D and 3D culture, with the greatest potency demonstrated by JQ1 and Mivebresib (ABBV-075). RNA-sequencing revealed dysregulated pathways in cell cycle division, DNA damage, apoptosis and MAPK signaling following iBET treatment. Reverse engineering of transcriptional profiles using Genexplain revealed that FGFR3 is a significantly upregulated master regulator (MTR) among 142 MTRs across both cell lines and both iBETs. Upregulation of FGFR3 after iBET treatment was verified at the protein level by Western blotting. We also show that BRD3 and FGFR3 knockdown significantly inhibited cell growth, which supports the key role both play in ILC progression. Further, we analyzed the iBET therapeutic effect when combined with the FGFR inhibitor, erdafitinib, as a strategy to overcome potential resistance due to FGFR upregulation post iBET treatment. This revealed that the combination of iBET and erdafitinib could inhibit ILC cell growth more effectively compared to using either agent alone. Furthermore, our in vivo study showed that JQ1 could inhibit tumor growth in a SUM44-MIND model and alleviate metastasis to peritoneum, bone and ovary compared with the vehicle group. Moreover, we also assessed the combination of mivebresib and erdafitinib in vivo. This revealed that iBET and an FGFR inhibitor work synergistically to decrease tumour burden and metastatic potential in both MM134-MIND and SUM44-MIND models. Conclusion: Our results provide evidence that iBET, either alone or in combination with erdafitinib, is remarkably effective at inhibiting ILC growth, both in vitro and in vivo and represents a rational therapeutic strategy for recurrent ILC patients in the future. Citation Format: Binbin Gao, Elspeth Ward, Anna Blümel, Emer Conroy, Rachel Moore, Grainne Cremin, Rachel Bleach, Kathryn Haley, Tríona Ní Chonghaíle, Andreas Lindner, Jochen Prehn, Yi Zhang, Idalia Cruz, Leena Hilakivi-Clarke, Georgios Sflomos, Cathrin Brisken, William Gallagher, Darran O'Connor. Rational therapeutic combination of Bromodomain and Extra-Terminal domain (BET) inhibitor and Fibroblast Growth Factor Receptor (FGFR) inhibitor for treatment of invasive lobular carcinoma [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-18-08.

Exploring MiR-484 Regulation by Polyalthia longifolia: A Promising Biomarker and Therapeutic Target in Cervical Cancer through Integrated Bioinformatics and an In Vitro Analysis.

MiR-484, implicated in various carcinomas, holds promise as a prognostic marker, yet its relevance to cervical cancer (CC) remains unclear. Our prior study demonstrated the Polyalthia longifolia downregulation of miR-484, inhibiting HeLa cells. This study investigates miR-484's potential as a biomarker and therapeutic target in CC through integrated bioinformatics and an in vitro analysis. MiR-484 levels were analyzed across cancers, including CC, from The Cancer Genome Atlas. The limma R package identified differentially expressed genes (DEGs) between high- and low-miR-484 CC cohorts. We assessed biological functions, tumor microenvironment (TME), immunotherapy, stemness, hypoxia, RNA methylation, and chemosensitivity differences. Prognostic genes relevant to miR-484 were identified through Cox regression and Kaplan-Meier analyses, and a prognostic model was captured via multivariate Cox regression. Single-cell RNA sequencing determined cell populations related to prognostic genes. qRT-PCR validated key genes, and the miR-484 effect on CC proliferation was assessed via an MTT assay. MiR-484 was upregulated in most tumors, including CC, with DEGs enriched in skin development, PI3K signaling, and immune processes. High miR-484 expression correlated with specific immune cell infiltration, hypoxia, and drug sensitivity. Prognostic genes identified were predominantly epidermal and stratified patients with CC into risk groups, with the low-risk group showing enhanced survival and immunotherapeutic responses. qRT-PCR confirmed FGFR3 upregulation in CC cells, and an miR-484 mimic reversed the P. longifolia inhibitory effect on HeLa proliferation. MiR-484 plays a crucial role in the CC progression and prognosis, suggesting its potential as a biomarker for targeted therapy.

Fibroblast growth factor receptor 3 activates a network of profibrotic signaling pathways to promote fibrosis in systemic sclerosis.

Aberrant activation of fibroblasts with progressive deposition of extracellular matrix is a key feature of systemic sclerosis (SSc), a prototypical idiopathic fibrotic disease. Here, we demonstrate that the profibrotic cytokine transforming growth factor β selectively up-regulates fibroblast growth factor receptor 3 (FGFR3) and its ligand FGF9 to promote fibroblast activation and tissue fibrosis, leading to a prominent FGFR3 signature in the SSc skin. Transcriptome profiling, in silico analysis and functional experiments revealed that FGFR3 induces multiple profibrotic pathways including endothelin, interleukin-4, and connective tissue growth factor signaling mediated by transcription factor CREB (cAMP response element-binding protein). Inhibition of FGFR3 signaling by fibroblast-specific knockout of FGFR3 or FGF9 or pharmacological inhibition of FGFR3 blocked fibroblast activation and attenuated experimental skin fibrosis in mice. These findings characterize FGFR3 as an upstream regulator of a network of profibrotic mediators in SSc and as a potential target for the treatment of fibrosis.

Abstract C052: FGF trapping impairs multiple myeloma growth through c-Myc degradation-induced mitochondrial oxidative stress

Abstract Multiple myeloma (MM) remains incurable because of chemotherapeutic resistance. Fibroblast growth factors (FGF) play a pivotal role in MM by acting as an autocrine/paracrine mitogen on plasma cells, bone marrow-derived endothelial cells and fibroblasts. Also, a recurrent chromosomal translocation t(4;14) is associated with FGFR3 upregulation in MM patients. Thus, agents able to hamper FGF signaling may represent a novel approach for MM treatment. Recently we have identified the PTX3-derived small molecule NSC12 as the first orally active antitumor pan-FGF trap. Here, the role of FGF/FGFR system in MM cell survival and the therapeutic potential of NSC12 were investigated. In vitro effects of NSC12 were tested on four human MM cell lines harboring (KMS-11 and OPM-2 cells) or not (U-266 and RPMI8226 cells) the t(4:14) translocation and on patient-derived MM cells (N = 26). In vivo effects of FGF blockade were investigated using subcutaneous (KMS-11 and RPMI8226 cells) and systemic (MM-1S cells) xenografts grown in NOD/SCID mice. In addition, gene expression profiling (GEP) and gene set enrichment analyses (GSEA) were performed in NSC12-treated MM cells. NSC12 blocked the proliferation of all human MM cell lines tested, causing inhibition of FGFR signaling, downregulation of the anti-apoptotic protein mcl-1 and caspase 3 activation. Cytofluorimetric analysis revealed a significant increase of apoptotic cells as early as 6 hrs after NSC12 treatment, with 100% of cell death after 24 hrs even when MM cells were co-cultured with patient-derived bone marrow stromal cells. In vivo, NSC12 blocked FGFR activation and reduced the growth of subcutaneous xenografts and MM cell dissemination in the BM. GEP and GSEA analyses of NSC12-treated cells revealed the upregulation of oxidative stress-induced genes and the downmodulation of c-Myc targets. Accordingly, NSC12 caused the rapid proteasomal degradation of c-Myc paralleled by GSH depletion, mitochondrial ROS production and depolarization, DNA damage and finally apoptosis in KMS-11 cells but not in KMS-11 cells expressing the undegradable mutated (T58A) form of c-Myc. Interestingly, these findings were confirmed on Bortezomib-resistant MM cells as well as on bone marrow-derived primary MM cells from newly diagnosed and relapsed/refractory patients, including plasma cells bearing the t(4;14) translocation obtained from high-risk MM patients. Our data reveal that FGF blockade triggers MM mitochondrial oxidative stress, DNA damage and apoptotic cell death via the proteasomal degradation of the c-Myc oncoprotein. Altogether, our findings dissect for the first time the mechanism by which the FGF/FGFR system plays a non-redundant role in MM cell survival and disease progression, and indicate that FGF targeting may represent a therapeutic approach for MM patients with poor prognosis and advanced disease stage. Citation Format: Roberto Ronca, Gaia Cristina Ghedini, Federica Maccarinelli, Antonio Sacco, Silvia Laura Locatelli, Eleonora Foglio, Sara Taranto, Elisabetta Grillo, Sara Matarazzo, Riccardo Castelli, Vanessa Desantis, Nadia Cattane, Annamaria Cattaneo, Marco Mor, Carmelo Carlo-Stella, Aldo Maria Roccaro, Marco Presta, Arianna Giacomini. FGF trapping impairs multiple myeloma growth through c-Myc degradation-induced mitochondrial oxidative stress [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C052. doi:10.1158/1535-7163.TARG-19-C052

Abstract A142: Targeting FGFR to overcome EMT-related resistance in EGFR-mutated non-small cell lung cancer

Abstract Epithelial-to-mesenchymal transition (EMT) has been identified as a mechanism of both adaptive and acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) in in vitro models and clinical samples of EGFR-mutated non-small cell lung cancer (NSCLC). However, a therapeutic strategy for targeting this mechanism remains unknown. In the setting of adaptive resistance early in the course of EGFR treatment, we observed that FGFR3 upregulation coincided with increased expression of mesenchymal genes, and a pooled shRNA dropout screen identified FGFR3 as a top sensitizer to EGFR inhibitor treatment. Dual FGFR (BGJ398) and EGFR (gefitinib) inhibition suppressed the outgrowth of drug-tolerant persister clones compared to EGFR TKI alone in vitro. Finally, we observed that the combination of BGJ398 and gefitinib prevented the development of in vivo resistance in PC9 xenograft mouse models. These results suggest that dual FGFR-EGFR blockade may be an effective strategy for preventing resistance associated with EMT in EGFR mutant NSCLC. Citation Format: Sana Raoof, David Ruddy, Daria Timonia, Leah Damon, Jeff Engelman, Aaron Hata. Targeting FGFR to overcome EMT-related resistance in EGFR-mutated non-small cell lung cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A142.

Angiogenic gene expression in primary neuroendocrine tumors and their metastases.

200 Background: Neuroendocrine tumors (NETs) are neoplasms arising from the cells of the nervous, endocrine and hormonal systems. They most commonly originate in the small bowel (SB) and frequently metastasize to the lymph nodes (LNs) and/or liver (LV). Current treatment of metastatic NETs involves a variety of approaches including antiangiogenic therapies. Our group demonstrated that there are significant histologic and functional differences between the primary NETs and their nodal or organ metastases. We hypothesized that sampling of multiple tumor sites within the same individual will reveal differential expression profiles of angiogenesis-related genes. Methods: Tissue-matched normal and tumor tissue samples were obtained from patients with well differentiated NETs who underwent simultaneous removal of their primary tumor, nodal, and organ metastasis. High quality RNA was extracted from each tumor site using TRIzol and RNeasy Mini kit. Gene expression of 28 well-documented angiogenesis-related genes was assessed using Custom Quantitative RT-PCR array. These gene expression trends were validated by Illumina microarray and TaqMan analysis. Immunohistochemistry (IHC) staining was performed using Avidin-Biotin-Peroxidase complex, with the markers: SSTR2 and FGFR3. Results: Normal SB, LN, and LV gene expression of 28 genes was compared to that of the tumor sample at each tumor site [4-fold change, p ≤ 0.01]. A consistent up-regulation of SSTR2 and SSTR1 was seen in 18/24 (75%) samples. Up-regulation of FGFR3 and SSTR5 was observed in 13/24 (50%) of tumors. TGFA and IGF were consistently down-regulated in 12/24 (50%) and 10/24 (42%) of tumor samples, respectively. Six genes expression trends were validated by TaqMan analysis and Illumina microarray analysis. IHC staining revealed higher SSTR2 and FGFR3 protein expression in all three tumor sites compared to the control. Conclusions: Expression of angiogenesis-related genes varies between the primary tumor (SB) and metastatic sites (LV, LN) within the same individual. We found a positive correlation between SSTR2 and FGFR3 gene and protein expression levels in all three tumor sites.

Abstract B77: The BET bromodomain inhibitor OTX015 (MK-8628) in mantle cell lymphoma (MCL): in vivo activity and identification of novel combinations to overcome adaptive resistance

Abstract OTX015 (MK-8628) has shown anti-lymphoma activity in both the preclinical and clinical settings (Boi et al, CCR 2015; Stathis et al, EORT-NCI-AACR 2014). Now, we report in vivo and in vitro data on OTX015 in MCL, including combination regimens. Methods. NOD-Scid (NOD.CB17-Prkdcscid/NCrHsd) mice were subcutaneously inoculated with 15 x106 MCL REC1 cells. Tumor size was measured twice weekly using digital calipers. Tumor volumes were calculated using the equation V = [length x width2]/2, in which the width and the length are the shortest and the longest diameters of each tumor, respectively. Gene expression profiling (GEP) was performed with Illumina HumanHT12 Expression BeadChips. Combinations were evaluated using the Chou-Talalay combination index (CI): <0.9, synergism; 0.9-1.1 additive effect; >1.2, no benefit. Results. Since we had previously reported in vitro activity of OTX015 as single agent in MCL cell lines (Boi et al, CCR 2015), we first confirmed its antitumor activity in an in vivo model. Mice were treated with OTX015 (50 mg/kg once daily; QDx7/w x5w) started 3 days after the graft. OTX015-treated mice did not show any weight loss. OTX015-treated REC1 xenografts presented a 2-fold decrease in volume compared with the control group (p< 0.05). To better understand the activity of OTX015 in MCL and to identify rational combinations that may overcome adaptive resistance mechanisms, GEP was performed on three sensitive (Rec1, Maver1, Jeko1) and one resistant MCL cell lines (Granta519, IC50 >10000 nM) exposed to DMSO or OTX015 (500 nM) for 2, 4, 8 or 12 hr. Despite the difference in the IC50 values between the three OTX015 sensitive cell lines and Granta-519, GEP changes were similar, and support the previously reported synergisms of OTX015 with ibrutinib and lenalidomide (Bernasconi et al, ASH 2014). Downregulated transcripts were enriched for MYC targets, genes involved in interferon response, in NFKB signaling, in MYD88 signaling, in B cell activation, genes more expressed in MCL than in CLL or DLBCL. TNFRSF17, TNFRSF13B, TLR10, CD72, VPREB3, PLEK, PTPN6 were among the most down-regulated transcripts, while the most upregulated ones comprised genes coding different histones of the clusters 1-2, PPP1R13B, CDKN2D (p19), IRF7, FGFR3, HES6. The upregulation of few transcripts, including HES and FGFR3, more pronounced in the resistant cell line, were suggestive of adaptive resistance mechanisms. We thus evaluated the combination of OTX015 with inhibitors of FGFR (PD173074) or MEK (pimasertib), which might counteract FGFR3 upregulation. Both combinations increased the antiproliferative effect of OTX015 in the sensitive cell line Jeko1 (CI values of 0.83 and 0.37, respectively). The combination with pimasertib was able to increase the sensitivity to OTX015 also in the resistant cell line (CI = 0.18), although it was not able to completely reverse its primary resistance. Conclusions. OTX015 showed in vivo activity as a single agent in MCL. GEP identified new combinations with MEK and FGFR inhibitors with the potential to overcome adaptive resistance. Citation Format: Eugenio Gaudio, Elena Bernasconi, Chiara Tarantelli, Luciano Cascione, Ivo Kwee, Andrea Rinaldi, Maurilio Ponzoni, Maria E. Riveiro, Emanuele Zucca, Francesco Bertoni. The BET bromodomain inhibitor OTX015 (MK-8628) in mantle cell lymphoma (MCL): in vivo activity and identification of novel combinations to overcome adaptive resistance. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B77.

In Multiple Myeloma, High-Risk Features Are Modulated By Other Chromosomal changes : A Large Snparray IFM Study

▪In multiple myeloma, cytogenetic changes display important value for patients’ outcome. In this setting, the most important changes are the del(17p), and the t(4;14), conferring a poor outcome. However, a certain heterogeneity is observed in survival of these high-risk patients. We hypothesized that other chromosomal changes may impact the outcome. We retrospectively analyzed a large series of 242 patients displaying either the t(4;14) (157 patients), or the del(17p) (110 patients), 25 patients presenting both abnormalities, using SNP-array. The main advantage of SNParray analyses is that all the unbalanced chromosomal changes are analyzed, in contrast to FISH which informs only for the chosed probes. For t(4;14), 144 patients have relapsed, and 103 have died. The median PFS was 1.4 year, and the median OS was 3.5 years. The median beta2-microglobulin (b2m) level was 4.0 mg/L (range, 1.2-38.3). The distribution of ISS stages 1, 2, and 3 was 35.4%, 26.4%, and 38.2%, respectively. Based on FISH results, 31.2% of the patients presented the abnormal configuration with only one fused signal. In all these patients, SNP-array analysis showed a loss of the telomeric part of one chromosome 4. In contrast to previous reports on this particularity in which the explanation was a loss of the derivative chromosome 14,17,18 we clearly show here that this configuration results from an unbalanced translocation. In patients with t(4;14), del(1p32) (p<0.001), del(16q) (p=0.03), del22q (p=0.04) and more than 30 chromosomal structural changes (p=0.02) negatively impacted PFS. For OS, del(13q14) (p=0.01), del(1p32) (p<0.001), and the number of chromosomal structural changes (p<0.05 and p=0.01 for [10;30[and more than 30 structural changes, respectively) worsened the prognosis of patients.In patients with del(17p) (110 patients), 99 patients relapsed, and 83 died. The median PFS was 1.3 year and the median OS was 2.7 years. The median beta2-microglobulin (b2m) level was 4.4 mg/L (range, 1.4-32.1). The distribution of ISS stages 1, 2, and 3 was 28.4%, 26.9%, and 44.8%, respectively. For patients with del(17p), del(1p32) (p<0.001), del(16q)] (p=0.03), del22q (p=0.04) and more than 30 chromosomal structural changes (p=0.02) negatively impacted PFS. For OS, del(1p32) (p=0.004) worsened the prognosis of patients, whereas more than 8 trisomies (p=0.008) was found to have a protective effect on survival.This study, which is the largest series of high-risk patients, analyzed with the most modern genomic technique, identified two main factors negatively impacting survival: del(1p32) and genomic complexity. Furthermore, we did show that 1/3 of patients with t(4;14) did not display upregulation of FGFR3 because of loss of the telomeric part of the chromosome 4. These patients do not present a better prognosis than those upregulating FGFR3, reinforcing the idea that FGFR3 activation is not important in the biology of the t(4;14). DisclosuresNo relevant conflicts of interest to declare.

The involvement of miR-100 in bladder urothelial carcinogenesis changing the expression levels of mRNA and proteins of genes related to cell proliferation, survival, apoptosis and chromosomal stability.

IntroductionMicroRNAs (miRNA) are small non-coding RNAs that play an important role in the control of gene expression by inhibiting protein translation or promoting messenger RNA degradation. Today, miRNAs have been shown to be involved in various physiological and pathological cellular processes, including cancer, where they can act as oncogenes or tumor suppressor genes. Recently, lowered expression of miR-100, resulting in upregulation of FGFR3, has been correlated with low-grade, non-invasive bladder urothelial cancer, as an alternative oncogenesis pathway to the typical FGFR3 gene mutation. Our aim is to analyze the role of miR-100 in bladder cancer cell lines in controlling the expression of some of its possible target genes, including FGFR3 and its relationship with proliferation, apoptosis and DNA ploidy.MethodsThe bladder cancer cell lines RT4 and T24 were transfected with pre-miR 100, anti-miR 100 and their respective controls using a lipid-based formulation. After transfection mRNA and protein levels of its supposed target genes THAP2, BAZ2A, mTOR, SMARCA5 and FGFR3 were analyzed by quantitative real time polymerase chain reaction (qRT-PCR) and western blotting. Cell proliferation, apoptosis and DNA ploidy were analyzed by flow cytometry. For statistical analysis, a t-test was applied, p < 0.05 was considered significant.ResultsAfter miR-100 transfection, there was a significant reduction in the mRNA of mTOR (p = 0.006), SMARCA5 (p = 0.007) and BAZ2A (p = 0.029) in RT4, mTOR (p = 0.023) and SMARCA5 (p = 0.015) in T24. There was a reduction in the expression of all proteins, variable from 22.5% to 57.1% in both cell lines. In T24 miR-100 promoted an increase in cell proliferation and anti-miR 100 promoted apoptosis characterizing miR-100 as an oncomiR in this cell line representative of a high-grade urothelial carcinoma.ConclusionmiR-100 transfection reduces expression of BAZ2A, mTOR and SMARCA5 mRNA and protein in BC cell lines. miR-100 would be classified as an oncomiR in T24 cells representative of high grade urothelial carcinoma promoting increase in cell proliferation and reduction in apoptosis. The knowledge of miRNA role in tumors will allow their use as tumor markers and targets for new therapies.

Genetic inhibition of fibroblast growth factor receptor 1 in knee cartilage attenuates the degeneration of articular cartilage in adult mice

Fibroblast growth factor (FGF) family members are involved in the regulation of articular cartilage homeostasis. The aim of this study was to investigate the function of FGF receptor 1 (FGFR-1) in the development of osteoarthritis (OA) and its underlying mechanisms. FGFR-1 was deleted from the articular chondrocytes of adult mice in a cartilage-specific and tamoxifen-inducible manner. Two OA models (aging-associated spontaneous OA, and destabilization-induced OA), as well as an antigen-induced arthritis (AIA) model, were established and tested in Fgfr1-deficient and wild-type (WT) mice. Alterations in cartilage structure and the loss of proteoglycan were assessed in the knee joints of mice of either genotype, using these 3 arthritis models. Primary chondrocytes were isolated and the expression of key regulatory molecules was assessed quantitatively. In addition, the effect of an FGFR-1 inhibitor on human articular chondrocytes was examined. The gross morphologic features of Fgfr1-deficient mice were comparable with those of WT mice at both the postnatal and adult stages. The articular cartilage of 12-month-old Fgfr1-deficient mice displayed greater aggrecan staining compared to 12-month-old WT mice. Fgfr1 deficiency conferred resistance to the proteoglycan loss induced by AIA and attenuated the development of cartilage destruction after surgically induced destabilization of the knee joint. The chondroprotective effect of FGFR-1 inhibition was largely associated with decreased expression of matrix metalloproteinase 13 (MMP-13) and up-regulation of FGFR-3 in mouse and human articular chondrocytes. Disruption of FGFR-1 in adult mouse articular chondrocytes inhibits the progression of cartilage degeneration. Down-regulation of MMP-13 expression and up-regulation of FGFR-3 levels may contribute to the phenotypic changes observed in Fgfr1-deficient mice.

Distinct MicroRNA Alterations Characterize High- and Low-Grade Bladder Cancer

Urothelial carcinoma of the bladder (UCC) is a common disease that arises by at least two different molecular pathways. The biology of UCC is incompletely understood, making the management of this disease difficult. Recent evidence implicates a regulatory role for microRNA in cancer. We hypothesized that altered microRNA expression contributes to UCC carcinogenesis. To test this hypothesis, we examined the expression of 322 microRNAs and their processing machinery in 78 normal and malignant urothelial samples using real-time rtPCR. Genes targeted by differentially expressed microRNA were investigated using real-time quantification and microRNA knockdown. We also examined the role of aberrant DNA hypermethylation in microRNA downregulation. We found that altered microRNA expression is common in UCC and occurs early in tumorogenesis. In normal urothelium from patients with UCC, 11% of microRNAs had altered expression when compared with disease-free controls. This was associated with upregulation of Dicer, Drosha, and Exportin 5. In UCC, microRNA alterations occur in a tumor phenotype-specific manner and can predict disease progression. High-grade UCC were characterized by microRNA upregulation, including microRNA-21 that suppresses p53 function. In low-grade UCC, there was downregulation of many microRNA molecules. In particular, loss of microRNAs-99a/100 leads to upregulation of FGFR3 before its mutation. Promoter hypermethylation is partly responsible for microRNA downregulation. In conclusion, distinct microRNA alterations characterize UCC and target genes in a pathway-specific manner. These data reveal new insights into the disease biology and have implications regarding tumor diagnosis, prognosis and therapy.

MicroRNA Expression Profiles in Korean Non-Small Cell Lung Cancer

Background: MicroRNAs (miRNAs) play an important role in the regulation of cell proliferation, apoptosis, development and differentiation. Several studies have shown that aberrant expression of miRNAs is involved in cancer development and progression by regulating the expression of proto-oncogenes or tumor suppressor genes. In this study, we investigated miRNA expression profiles in Korean patients with non-small cell lung cancer (NSCLC). Methods: We performed miRNA microarray analysis containing 60~65 bp oligonucleotide probes representing human 318 miRNAs and validated the results of the microarray with Northern blot analysis or quantitative RT-PCR. Next, we examined the correlation between miRNA expression and the target gene transcriptional profile using a human whole-genome-expression microarray. Results: We showed that 35 miRNAs were expressed differentially in the NSCLCs and corresponding non-malignant lung tissues. We showed that 35 miRNAs were expressed differentially in the NSCLCs and corresponding nonmalignant lung tissues. Thirteen of the 35 differentially expressed miRNAs were newly identified in the present study. Of the 35 miRNAs, 2 (miR-371 and miR-210) were over-expressed in lung cancers, and 33 miRNAs, including miR-145, were under-expressed in lung cancers. miR-99b expression consistently showed a negative correlation with FGFR3 expression. Conclusion: Albeit a small number of patients were examined, these results suggest that miRNA expression profiles in Korean lung cancers may be somewhat different from the expression profiles reported on lung cancers in Western populations. The findings suggest that miR-99b might be a tumor suppressor through its up-regulation of FGFR3.

Molecular Classification of Multiple Myeloma (MM) Based on Gene Expression Profiling (GEP) and Fluorescence In Situ Hybridisation (FISH) Is an Independent Predictor for Event Free Survival (EFS).

AIM was to test the new molecular classification of MM based on changes in global gene expression attributable to cytogenetic aberrations detected by interphase FISH (iFISH) in order to (i) predict EFS in a group of 100 MM-patients treated by high dose chemotherapy, and (ii) to investigate whether the classification represents an independent prognostic factor.PATIENTS AND METHODS. Bone marrow aspirates from MM-patients and normal donors were CD138-purified by magnetic activated cell sorting. RNA was in-vitro transcribed and hybridised to Affymetrix HG U133 A+B GeneChip (TG) and HG U133 2.0 plus array (VG). CCND1, CCND2 and FGFR3 expression was verified by real time RT-PCR and western blotting. iFISH was performed on purified MM-cells using probes for chromosomes 11q23, 13q14, 17p13 and the IgH-translocations t(4;14)(p16;q32.3) and t(11;14)(q13;q32.3). Expression data were normalised (Bioconductor package gcrma), and nearest shrunken centroids (NSC) applied to calculate and cross validate a predictor on a training group (TG) of 40 patients in whom a comprehensive iFISH panel combined with data on CCND overexpression were available. The ExpressMiner tool of the HUSAR bioinformatics laboratory was used to analyze genes differentially expressed between GEP-defined groups. A log-rank test and a Cox proportional hazard model were used to test the influence of prognostic parameters in combination with the predicted groups.RESULTS. Four groups were distinguished: (1.1) CCND1 (11q13) overexpression and trisomy 11q13, (1.2) CCND1 overexpression and translocations involving 11q13, i.e. t(11;14), (2.1) CCND2 overexpression without 11q13+, t(11;14), t(4;14), (2.2) CCND2 overexpression with t(4;14) and FGFR3 upregulation. A predictor of 6 genes correctly classified all 40 patients of the TG (estimated cross validated error rate 0%). An independent validation group (VG) of 65 patients was used. Distribution of clinical parameters (i.e. beta2M, Durie Salmon stages, ISS) was not significantly different between the 4 groups. The groups defined by the predictor have a significantly different EFS after autologous stem cell transplantation according to the GMMG-HD3 protocol (n=100; median: 26 /not reached /22 /6 months in groups 1.1 /1.2 /2.1 /2.2, respectively). A model testing the combination of the predicted group and B2M (above or below 3.5 mg/dl) showed a significant (p<0.006, log-rank-test) correlation with EFS. The distribution of del(13q14) (n=118) was (1.1) 34.0%, (1.2) 60.8%, (2.1) 46.4% and (2.2) 94%. The presence of a del(13q14) either in a subclone (<60% of analyzed nuclei) or major clone had no significant influence on EFS.CONCLUSION. Gene expression and iFISH allow a molecular classification of MM which can be predicted by GEP. Groups in the classification have distinct gene expression patterns as well as statistically significant different EFS. GEP-defined groups and B2M represent independent prognostic parameters.

A New Molecular Classification of Multiple Myeloma Using Gene Expression Profiling and Fluorescence In Situ Hybridisation as Predictor for Event Free Survival.

AIM was to establish a new molecular classification of Multiple Myeloma (MM) based on changes in global gene expression attributable to cytogenetic aberrations detected by interphase FISH (iFISH) in order to (i) predict event free survival (EFS) and (ii) investigate differentially expressed genes as basis for a group specific and risk adapted therapy.PATIENTS AND METHODS. Bone marrow aspirates of 105 newly diagnosed MM-patients (65 trial (TG) / 40 independent validation group (VG)) and 7 normal donors (ND) were CD138-purified by magnetic activated cell sorting. RNA was in-vitro transcribed and hybridised to Affymetrix HG U133 A+B GeneChip (TG) and HG U133 2.0 plus arrays (VG). CCND1 and CCND2 expression was verified by real time RT-PCR. iFISH was performed on purified MM-cells using probes for chromosomes 11q23, 11q13, 13q14, 17p13 and the IgH-translocations t(4;14) and t(11;14). Expression data were normalised (Bioconductor package gcrma) and nearest shrunken centroids (NSC) applied to calculate and cross validate a predictor on 40 patients of the TG with a comprehensive iFISH panel available combined with CCND overexpression. Differentially expressed genes were identified using empirical Bayes statistics for pairwise comparison.RESULTS. Overexpression of a D-type cyclin (D1 or D2) was found in 61/65 patients with MM compared to ND. CCND3 overexpression only appeared concomitantly with CCND2 overexpression. Four groups could be distinguished: (1.1) CCND1 (11q13) overexpression and trisomy 11q13, (1.2) CCND1 overexpression and translocations involving 11q13 i.e. t(11;14), (2.1) CCND2 overexpression without 11q13+, t(11;14), t(4;14), (2.2) CCND2 overexpression with t(4;14) and FGFR3 upregulation. A predictor of 6 to 566 genes correctly classifies all 40 patients of the TG (estimated cross validated error rate 0%). An independent VG of 40 patients was used. Genes with highest scores in NSC are: (1.1) CCND1, ribosomal proteins (e.g. RPL 28, 29), GPX1, CCRL2, (1.2) CCND1, TGIF, and NCAM (non-overexpression), (2.1) CCND2, (2.2) FGFR3, WHSC1, CCND2, IRTA2, SELL, and MAGED4. Distribution of clinical parameters (i.e. β2M, Durie Salmon stages, ISS) was not significantly different between the groups. The distribution of del(13)(q14q14) was (1.1) 31.5%, (1.2) 37.5%, (2.1) 37.5% and (2.2) 100%. (p<0.01). I.e. HGF, DKK1, VCAM, CD163 are differentially expressed between all 4 groups and ND (adjusted p<0.001). The groups defined by the predictor show a significantly different EFS after autologous stem cell transplantation according to the GMMG-HD3 protocol (median: (1.1) 18 / (1.2) not reached (no event) / (2.1) 22 / (2.2) 6 months; log-rank-test: p=0.004).CONCLUSION. CCND1 or CCND2 overexpression is nearly ubiquitous in MM and attributable to defined cytogenetic aberrations. Gene expression and iFISH allow a molecular classification of MM which can be predicted by gene expression profiling alone. Groups in the classification show a distinctive pattern in gene expression as well as a different EFS interpretable as risk stratification and indicator of therapeutic targets.

Genomic abnormalities in monoclonal gammopathy of undetermined significance

Translocations involving immunoglobulin (Ig) loci and chromosome 13 monosomy (Delta 13) are frequent cytogenetic findings in multiple myeloma (MM). Similar chromosomal aberrations have been identified in the monoclonal gammopathy of undetermined significance (MGUS), but their prevalence and significance remain uncertain. Bone marrow from 72 patients with MGUS (n = 62) and smoldering MM (n = 10) was evaluated for translocations between the Ig heavy chain (IgH) and chromosomes 4, 11, and 16, translocations involving Ig light chain-lambda (IgL-lambda, and Delta 13. Fluorescence in situ hybridization (FISH) analysis was done on clonal plasma cells (PCs) detected by immunofluorescence (cIg-FISH) of the cytoplasmic light chain. We also studied cells for cyclin D1 and FGFR3 up-regulation by immunohistochemistry and immunofluorescence, respectively. Twenty-seven (46%) of 59 patients had IgH translocations, and 4 (11%) of 37 had an IgL-lambda translocation. A t(11;14)(q13;q32) was found in 15 (25%) of 59 patients, a t(4;14)(p16.3;q32) in 9% of patients, and a t(14;16)(q32;q23) in 5% of patients. All patients with t(4;14)(p16.3;q32) tested (n = 3) had intense cytoplasmic fluorescence with an anti-FGFR3 antibody. PC nuclear staining of cyclin D1 was only observed in patients with t(11;14)(q13;q32); Delta 13 was detected in the clonal PCs in 50% of patients. The percentage of abnormal PCs varied with any given abnormality. No obvious clinical or biologic correlations were associated with these chromosome abnormalities. Similar translocations are found in both MGUS and MM, including t(4;14)(p16.3;q32) and t(14;16)(q32;q23). Moreover, Delta 13 is common in MGUS and unlikely to play a predominant role in the evolution of MGUS to MM.

The site of action of neuronal acidic fibroblast growth factor is the organ of Corti of the rat cochlea.

Here we show that the mature cochlear neurons are a rich source of acidic fibroblast growth factor (aFGF), which is expressed in the neuronal circuitry consisting of afferent and efferent innervation. The site of action of neuronal aFGF is likely to reside in the organ of Corti, where one of the four known FGF receptor (FGFR) tyrosine kinases--namely, FGFR-3 mRNA--is expressed. Following acoustic overstimulation, known to cause damage to the organ of Corti, a rapid up-regulation of FGFR-3 is evident in this sensory epithelium, at both mRNA and protein levels. The present results provide in vivo evidence for aFGF being a sensory neuron-derived, anterogradely transported factor that may exert trophic effects on a peripheral target tissue. In this sensory system, aFGF, rather than being a neurotrophic factor, seems to promote maintenance of the integrity of the organ of Corti. In addition, aFGF, released from the traumatized nerve endings, may be one of the first signals initiating protective recovery and repair processes following damaging auditory stimuli.