FGFR1 Gene Expression Research Articles

Abstract 341: Overexpression of FGFR2 gene is associated with advanced stage squamous cell carcinoma of the lung

Abstract Introduction: Molecular oncology has revealed various types of genetic abnormality are involved in tumorigenesis of lung carcinomas. For example, mutations of epidermal growth factor receptor (EGFR) are associated with non-smoker patients with lung adenocarcinomas, and mutations of K-ras are associated with smoker patients with lung adenocarcinomas. However, few genetic abnormalities were reported in squamous cell carcinomas of the lung. In order to identify the specific genetic abnormality in squamous cell carcinoma of the lung, we performed a clinical study on the fibroblast growth factor receptor (FGFR) gene in patients with non-small cell lung cancers (NSCLCs). Method: One hundred and thirty eight NSCLC patients were studied. Quantitative real-time PCR was performed to evaluate gene expressions of all four members of human FGFR, including FGFR1, FGFR2, FGFR3, and FGFR4. In addition, gene status of EGFR (exon 19-22), K-ras (exon 1), and p53 (exon 5-8) was also investigated using PCR-SSCP confirmed by direct sequencing. Results: FGFR2 gene expression was significantly higher in smoker patients than in non-smoker patients (P=0.008). Regarding the tumor histology, FGFR2 gene expression was significantly higher in squamous cell carcinomas than in adenocarcinomas (P<0.001). Furthermore, among squamous cell carcinomas, FGFR2 gene expression was significantly higher in advanced stage tumors than in early stage tumors (P=0.034). Among squamous cell carcinomas, FGFR1 gene expression was also significantly higher in advanced stage tumors than in early stage tumors (P=0.031). In contrast, there was no these relationships in FGFR3 gene expression or FGFR4 gene expression. Regarding other gene status, FGFR2 gene expression was significantly higher in tumors with wild-type of EGFR than in tumors with mutant EGFR (P=0.004), and was likely to be higher in tumors with wild-type of K-ras than in tumors with mutant K-ras. Furthermore, FGFR1 gene expression was likely to be higher in tumors with wild-type of K-ras than in tumors with mutant K-ras (P=0.064). However, there was no difference in FGFR3 gene expression or FGFR4 gene expression according to EGFR gene status and K-ras gene status. In addition, there was no difference in gene expression of FGFR1, FGFR2, FGFR3, or FGFR4 according to p53 gene status. Conclusions: Overexpression of FGFR2 gene expression is associated with lung carcinomas with wild-type of EGFR and wild-type of K-ras, especially in advanced stage of squamous cell carcinomas. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 341. doi:10.1158/1538-7445.AM2011-341

Quantitation of angiogenesis in vitro induced~by VEGF-A and FGF-2 in two different human endothelial cultures – an all-in-one assay

Angiogenic therapy is considered to be a promising tool for treatment of ischemic diseases. Many in vivo and in vitro assays have been developed to identify potential proangiogenic drugs and to investigate their mode of action. However, until now no validated system exists that would allow quantitation of angiogenesis in vitro in only one assay. Here, a previously established all-in-one in vitro assay based on staging of the angiogenic cascade was validated by quantitation of the effects of the known proangiogenic factors VEGF-A and FGF-2. Both growth factors were applied separately or in combination to human endothelial cell cultures derived from the heart and the foreskin, and angiogenesis was quantitated over 30 days of culture. Additionally, gene expression of VEGFR-1, VEGFR-2 and FGFR-1 at 3, 10, 20 or 40 days of cultivation was quantitated by RT-qPCR. In both cultures, VEGF-A as well as FGF-2 induced a run through all defined stages of angiogenesis in vitro. Application of VEGF-A only led to formation of irregular globular endothelial structures, while FGF-2 resulted in development of regular capillary-like structures. Quantitation of the angiogenic effects of VEGF-A and transcripts of VEGFR-1 and VEGFR-2 showed that a high VEGFR-1/VEGFR-2 ratio evoked deceleration of angiogenesis.

Vitamin K2 downregulates the expression of fibroblast growth factor receptor 3 in human hepatocellular carcinoma cells

Vitamin K2 exerts an antitumor activity on human hepatocellular carcinoma (HCC), however, its inhibitory mechanism has not yet been clarified. This study was designed to identify the attractive target molecule of vitamin K2 and shed some light on its effects on fibroblast growth factor receptor (FGFR)3 in HCC cells. The changes in the gene expression of HuH-7 after vitamin K2 treatment were evaluated by a DNA chip analysis. The mRNA and protein levels of FGFR were evaluated by semiquantitative reverse transcription polymerase chain reaction (RT-PCR), real-time PCR and western blot analysis. The promoter activity of the FGFR3 gene was measured by a dual-luciferase assay. The DNA chip analysis revealed different inhibitory rates of gene expression of FGFR3 (60.6%) and FGFR1 (19.4%) after vitamin K2 treatment. Vitamin K2 suppresses the proliferation of HuH-7 in a dose-dependent manner and its inhibitory rate reached approximately 61.8% at the dose of 30 microM. FGFR3 mRNA was significantly reduced based on semiquantitative RT-PCR and decreased 61.5% by a real-time PCR method after vitamin K2 treatment, but FGFR1 mRNA was not. The level of FGFR3 protein was also reduced by vitamin K2 treatment. The luciferase assay demonstrated that vitamin K2 significantly suppressed the promoter activity of FGFR3. Furthermore, the FGFR3-ERK1/2 signaling pathway was suppressed by vitamin K2 treatment. These findings suggest that vitamin K2 may suppress the proliferation of HCC cells through the downregulation of the FGFR3 expression. The transcriptional suppression of FGFR3 may be a novel mechanism of the vitamin K2 action for HCC cells.

Histone-Acetylated Control of Fibroblast Growth Factor Receptor 2 Intron 2 Polymorphisms and Isoform Splicing in Breast Cancer

Recent genome-wide association studies have identified fibroblast growth factor receptor (FGFR)2 as one of a few candidate genes linked with breast cancer susceptibility. In particular, the disease-predisposing allele of FGFR2 is inherited as a 7.5-kb region within intron 2 that harbors eight single nucleotide polymorphisms. The relationship between these single nucleotide polymorphisms and FGFR2 gene expression remains unclear. Here we show the common occurrence of polymorphisms within the intron 2 region in a panel of 10 breast cancer cell lines. High FGFR2-expressing cell lines such as MCF-7 cells displayed polymorphic sequences with constitutive histone acetylation at multiple intron 2 sequences harboring putative transcription binding sites. Knockdown of Runx2 or CCAAT enhancer binding protein beta in these cells resulted in diminished endogenous FGFR2 gene expression. In contrast FGFR2-negative MDA-231 cells were wild type and showed evidence of histone 3/4 deacetylation at the rs2981578, rs10736303, and rs7895676 disease-associated alleles that harbor binding sites for Runx2, estrogen receptor, and CCAAT enhancer binding protein beta, respectively. Histone deacetylation inhibition with trichostatin A resulted in enhanced acetylation at these intron 2 sites, an effect associated with robust FGFR2 reexpression. Isoform analysis proved reexpression of the FGFR2-IIIc variant the splicing of which was positively influenced by trichostatin A-mediated recruitment of the Fas-activated serine/threonine phosphoprotein survival protein. Our findings highlight the potential role of histone acetylation in modulating access to selected polymorphic sites within intron 2 as well as downstream splicing sites in generating variable FGFR2 levels and isoforms in breast cancer.

Cocaine interacts with the novelty-seeking trait to modulate FGFR1 gene expression in the rat

The present study sought to determine the interaction between the novelty-seeking trait and cocaine treatment on gene expression in the fibroblast growth factor (FGF) system. Specifically, we assessed the regulation of FGFR1 in response to cocaine in animals that were selectively bred on the basis of their locomotor response to a novel environment. High-responder (HR) rats are those that exhibit increased locomotor response and exploratory behavior in a novel environment and low-responder (LR) rats are those that exhibit lower levels of exploratory behavior and are less active. Both phenotypes received daily injections of either cocaine (15 mg/kg, i.p.) or saline for 7 consecutive days. Animals were sacrificed 45 min following their last injection and FGFR1 gene expression was assessed in the hippocampus and prefrontal cortex by mRNA in situ hybridization. HR-bred rats exhibited increased FGFR1 mRNA in the hippocampus compared to LR-bred rats. Furthermore, cocaine decreased FGFR1 mRNA in the hippocampus and increased FGFR1 mRNA in the prefrontal cortex. Finally, HR and LR rats differed in their response to cocaine between brain regions. In the hippocampus, cocaine decreased gene expression in HR-bred rats without affecting LR-bred rats, whereas in the prefrontal cortex cocaine increased gene expression in LR-bred rats without affecting HR-bred rats. These results suggest that cocaine interacts with the novelty-seeking trait to alter gene expression. Thus, the FGF system may contribute to individual differences in the response to drugs of abuse.

Endotoxin Alters Early Fetal Lung Morphogenesis

The effects of immaturity and hypoplasia of the premature lung can be affected by proinflammatory stimuli in late gestation or the postnatal period from acute lung injury secondary to intensive ventilatory management or the metabolic consequences of surgery. These stimuli alter alveolarization and contribute to bronchopulmonary dysplasia. While prior research has focused primarily on late gestational effects of inflammation on alveolar development, we sought to study whether early gestational exposure to endotoxin affects branching morphogenesis, during the critical pseudoglandular stage of lung development. Gestational day 15 (E15) fetal rat lung explants (term = 22 d) were treated with either 200 ng/mL or 2 microg/mL lipopolysaccharides (LPS) with controls and examined daily by phase microscopy. After 5 d, explants were fixed in 4% formaldehyde, paraffin embedded, and sectioned at 5 mum in the coronal plane. Immunohistochemical analysis was performed with platelet endothelial cell adhesion molecule (PECAM) to define endothelial cells, vascular endothelial growth factor (VEGF) to examine endothelial mitogenesis, and COX-2 antibodies as a marker for prostaglandin synthesis. Real-time PCR examined inducible nitric oxide synthase (iNOS), FGF9, FGF10, and FGFr2 gene expression. Air space fraction and airway epithelium were analyzed with Image J software. Phase contrast microscopy and hematoxylin-eosin histology revealed progressive, dose-related changes in air sac contraction and interstitial thickening. Compared with control E15 explants, day 5 explants incubated with high dose LPS demonstrated thickened and shrunken airway sacs with stunted branching and increased matrix deposition in interstitial areas. By immunohistochemical staining, COX-2 was quantitatively increased after high dose LPS exposure, while PECAM was reduced. VEGF expression was unaltered. LPS increased iNOS, but decreased FGF9, FGF10, and FGFr2 gene expression. These data support evidence for an inflammatory effect of LPS on the early phase of lung development in the fetal rat, affecting branching morphogenesis during the pseudoglandular phase. Fetal endothelial cells are clearly affected, while COX-2 elevation suggests activation of an as yet undefined fetal pulmonary inflammatory cascade. We speculate that proinflammatory stimuli may ultimately lead to abnormal pulmonary development via fibroblastic growth factor (FGF)-directed mechanisms that affect epithelial-mesenchymal interaction and differentiation at a much earlier gestational age than was previously recognized.

Decreased expression of Tgf‐beta ligands and receptors correlates with an aberrant proliferative response to estrogen in a mouse model of Brca1‐mutation‐related breast cancer.

Rationale: Loss of full length Brca1 in mammary epithelial cells of conditional knockout mice is associated with an abnormal proliferative response that promotes cancer progression following estrogen treatment. This study was conducted to find the mechanisms of this aberrant response. Expression levels of 16 growth factor ligands and receptors at transcriptional level were investigated. Methods: Post-pubertal female mice (6–12 months old) were either implanted with a 0.72 mg 60-day release estrogen or placebo Pellet (n=5, E2/n=5, PLC Brca1Co/CoMMTV-Cre and n=4, E2 /n=5, PLC WT). Eight weeks after pellet insertion, mice were euthanized, necropsied and mammary glands removed .RNA was extracted, cDNA prepared and RNA expression levels measured by Real Time RT-PCR. Results: Steady state RNA expression levels of Tgfβ1, Tgfβ2, TβR-I, TβR-II (Two-Way ANOVA P<0.0001), Tgfβ3 (Two-Way ANOVA P=0.0115) were lower in the mutant Brca1 mice compared to wild-type mice. No differences in expression levels of Vegfa, Flt4, Kdr, Figf, Kit, Tgfα, C-met, Hgf, Fgf7, Fgfr2 gene expression were found. Conclusions. Loss of full-length Brca1 in mammary epithelial cells was associated with decreased expression of Tgfβ family members. It is possible that decreased Tgfβ activity contributes to the abnormal and exaggerated growth response seen in Brca1 deficient mammary glands following estrogen treatment.

Design, synthesis, and evaluation of mitomycin-tethered phosphorothioate oligodeoxynucleotides.

Mitomycin C (1) is the prototypical bioreductive alkylating agent. Studies have shown that mitomycin C and its derivatives selectively alkylate guanine residues within di- and trinucleotide DNA sequences. This investigation sought to improve the selective DNA bonding properties of the mitomycins by coupling them with antisense oligodeoxynucleotides. Two procedures were developed that allowed the attachment of a phosphorothioate oligodeoxynucleotide containing a hexylamino spacer at the 5' terminus with a C(10)-activated mitomycin. In the first procedure, decarbamoylation of 1 (NaOCH3/ benzene) afforded 10-decarbamoylmitomycin C (10), which was treated with either dimethyl sulfate or methylthiochloroformate and base to yield 10-decarbamoylporfiromycin (11) and N(1a)-[(methylthio)-carbonyl]-10-decarbamoylmitomycin C (12), respectively. Activation of the C(10) site in 11 and 12 with 1,1'-carbonyldiimidazole or with 1,1'-thiocarbonyldiimidazole provided the N(1a)-substituted mitomycin 10-decarbamoyl-10-O-carbonylimidazoles (5, 7) and 10-decarbamoyl-10-O-thiocarbonylimidazoles (6, 8), respectively. Compounds 5-8 were reacted with glycine methyl ester hydrochloride (17) and base in both methylene chloride and aqueous buffered solutions to determine the ease and efficiency in which these C(10)-activated mitomycin derivatives coupled to amines. It was found that 5-8 all reacted with 17 in methylene chloride to give the coupled products 18-21 but that improved amine coupling yields in water were observed for the 10-decarbamoyl-10-O-thiocarbonylimidazoles 6 and 8 as compared with the 10-decarbamoyl-10-O-carbonylimidazoles 5 and 7. This finding led to the coupling of the phosphorothioate oligodeoxynucleotide, H2N(CH2)6-P(S)(OH)-GGCCCCGTG-GTGGCTCCAT (22) to 8. Compound 22 complemented a 19-base sequence in the translation initiation region of the human A-raf-1 gene. Use of excess 8 (28 equiv) with 22 gave only a 36% yield of the coupled product 23, which proved difficult to separate from 22. In the second procedure, phosphorothioate oligodexynucleotides that contained a hexylamino spacer at the 5'termini were coupled to 10-des(carbamoyloxy)-10-isothiocyanatoporfiromycin (9). Compound 9 was prepared in four steps from 11. Mesylation (methanesulfonyl chloride/pyridine) of 11 gave the C(10) mesylate 13, which was then treated with NaN3 (dimethylformamide, 90 degrees C) to give 10-des(carbamoyloxy)-10-azidoporfiromycin (14). Catalytic reduction (PtO2, H2) of 14 in pyridine afforded C(10) amine 15. Treatment of 15 with di-2-pyridyl thionocarbonate provided the desired 10-des(carbamoyloxy)-10-isothiocyanatoporfiromycin (9). Compound 9 readily coupled with 17 and base in both methylene chloride and aqueous buffered solutions to give 25. Use of the 5'hexylaminophosphorothioate oligodeoxynucleotides 32-35 in place of 17 gave the conjugated adducts 28-31, respectively, in a 12% to near-quantitative yield. The products were purified by semipreparative HPLC. Antisense agents 28-31 were designed to target a 30-base-long region from the coding region of the human FGFR1 gene. One adduct, 29, reduced the number of FGFR1 receptors in human aortic smooth cells for bFGF on the cell surface, which suggested down-regulation of FGFR1 gene expression. Further, 29 inhibited cultured human aortic smooth muscle cell proliferation and was less cytotoxic than porfiromycin (2). The biological assay data suggest that the phosphorothioate oligodexynucleotide porfiromycin conjugates may be more target selective and less toxic than either mitomycin or porfiromycin and thus be promising therapeutic agents.

Fibroblast growth factor receptor type 1 expression during rat testicular development and its regulation in cultured Sertoli cells.

In the present study, we examined the ontogeny of the type 1 receptor for basic fibroblast growth factor (FGFR-1) in whole rat testis, its cellular localization, and its in vitro regulation in 20-day-old rat Sertoli cells. Gene expression of FGFR-1 was developmentally regulated; expression was higher in prepubertal testes and decreased with sexual maturity. The transcript was found to be expressed in Leydig-enriched fractions, peritubular cells, Sertoli cells, and, to a lesser extent, germ cells. FSH as well as (Bu)2cAMP enhanced FGFR-1 messenger RNA (mRNA) levels in cultured Sertoli cells, suggesting an involvement of the protein kinase-A pathway. Addition of basic FGF (bFGF), tumor necrosis factor-alpha (TNF alpha), or interleukin-1 alpha resulted in a dose- and time-related increase in FGFR-1 mRNA levels. The effect of bFGF was specific, because it was neutralized by cotreatment with an anti-bFGF. We tested medium conditioned by germ cells and found a stimulation of the Sertoli cell FGFR-1 mRNA levels, which was abolished by immunodepletion of the conditioned medium with anti-TNF alpha antibodies. It is suggested that in Sertoli cells, bFGF action, when mediated by FGFR-1, is under a complex hormonal (FSH) and paracrine and/or autocrine control exerted at least by bFGF, TNF alpha, and interleukin-1 alpha.

Overexpression of the fibroblast growth factor receptor-1 gene correlates with liver metastasis in colorectal cancer

Expression of the fibroblast growth factor (FGF)-1, FGF-2, fibroblast growth factor receptor (FGFR)-1, and FGFR-2 genes has been reported in various cancers and is associated with poor outcomes in patients with solid tumors. This study examined the relations between the relative expression of the FGF genes and clinicopathological factors, especially invasion and metastasis, in patients with colorectal cancer. We studied surgical specimens of cancer tissue and adjacent normal mucosa obtained from 202 patients with untreated colorectal carcinoma. The relative expression levels of FGF-1, FGF-2, FGFR-1, and FGFR-2 mRNA in cancer and in normal adjacent mucosa were measured by quantitative real-time, reverse-transcription polymerase chain reaction. The relative expression level of the FGFR-2 gene was higher in normal adjacent mucosa than in cancer, whereas the relative expression levels of the FGF-1, FGF-2, and FGFR-1 genes were similar. FGFR-1 gene expression levels were higher in the presence than in the absence of liver metastasis. An analysis of the relation between clinicopathological features and gene expression showed that overexpression of FGFR-1 correlated with liver metastasis. Our results suggested that overexpression of the FGFR-1 gene might lead to liver metastasis in colorectal cancer. Overexpression of the FGFR-1 gene may thus be a useful predictor of liver metastasis in patients with colorectal cancer.