BACKGROUND

The recurrent immunoglobulin translocation, t(4;14)(p16;q32) occurs in <em>15</em>% of multiple myeloma patients and is associated with poor prognosis, through an unknown mechanism. The t(4;14) up-regulates <em>fibroblast</em> <em>growth</em> <em>factor</em> receptor 3 (FGFR3) and multiple myeloma SET domain (MMSET) genes. The involvement of MMSET in the pathogenesis of t(4;14) multiple myeloma and the mechanism or genes deregulated by MMSET upregulation are still unclear.

METHODS

The expression of MMSET was analyzed using a novel antibody. The involvement of MMSET in t(4;14) myelomagenesis was assessed by small interfering RNA mediated knockdown combined with several biological assays. In addition, the differential gene expression of MMSET-induced knockdown was analyzed with expression microarrays. MMSET gene targets in primary patient material was analyzed by expression microarrays.

RESULTS

We found that MMSET isoforms are expressed in multiple myeloma cell lines, being exclusively up-regulated in t(4;14)-positive cells. Suppression of MMSET expression affected cell proliferation by both decreasing cell viability and cell cycle progression of cells with the t(4;14) translocation. These findings were associated with reduced expression of genes involved in the regulation of cell cycle progression (e.g. CCND2, CCNG1, BRCA1, AURKA and CHEK1), apoptosis (CASP1, CASP4 and FOXO3A) and cell adhesion (ADAM9 and DSG2). Furthermore, we identified genes involved in the latter processes that were differentially expressed in t(4;14) multiple myeloma patient samples.

CONCLUSIONS

In conclusion, dysregulation of MMSET affects the expression of several genes involved in the regulation of cell cycle progression, cell adhesion and survival.

Addition of cholera toxin (100 ng/ml) to quiescent cultures of Swiss 3T3 cells acts synergistically with serum (2-4%), insulin, phorbol esters, epidermal <em>growth</em> <em>factor</em>, and <em>fibroblast</em>-derived <em>growth</em> <em>factor</em> to stimulate DNA synthesis. In the presence of insulin, cholera toxin caused a dose-dependent increase in cumulative [3H]thymidine incorporation into acid-insoluble material and in the intracellular cyclic AMP (cAMP) level. The dose--response curves for the two processes were similar. Furthermore, addition of 1-methyl-3-isobutylxanthine (<em>15</em>--500 microM) or of 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (5--100 microM), both of which are potent inhibitors of cyclic nucleotide phosphodiesterase which are potent inhibitors of cyclic nucleotide phosphodiesterase activity, stimulated DNA synthesis and increased cAMP levels in Swiss 3T3 cells. These compounds strikingly potentiated the effect of cholera toxin on DNA synthesis and on cAMP levels. When quiescent Swiss 3T3 cells were exposed to cholera toxin (100 ng/ml) and insulin at 10 micrograms/ml (4- to 7-fold increase in cAMP level) or to these agents and 1-methyl-3-isobutyl xanthine at 50 microM (35-fold increase in cAMP level), DNA synthesis began after a lag of 16 hr. These results indicate that cAMP acts as a mitogenic signal for Swiss 3T3 cells and differ from the widely held view that cyclic AMP inhibits the proliferation of <em>fibroblast</em> cells.

In general, human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs)(1) can be cultured under variable conditions. However, it is not easy to establish an effective system for culturing these cells. Since the culture conditions can influence gene expression that confers pluripotency in hESCs and hiPSCs, the optimization and standardization of the culture method is crucial. The establishment of hESC lines was first described by using MEFs as feeder cells and fetal bovine serum (FBS)-containing culture medium(2). Next, FBS was replaced with knockout serum replacement (KSR) and FGF2, which enhances proliferation of hESCs(3). Finally, feeder-free culture systems enable culturing cells on Matrigel-coated plates in KSR-containing conditioned medium (medium conditioned by MEFs)(4). Subsequently, hESCs culture conditions have moved towards feeder-free culture in chemically defined conditions(5-7). Moreover, to avoid the potential contamination by pathogens and animal proteins culture methods using xeno-free components have been established(8). To obtain improved conditions mouse feeder cells have been replaced with human cell lines (e.g. fetal muscle and skin cells(9), adult skin cells(10), foreskin <em>fibroblasts</em>(11-12), amniotic mesenchymal cells(13)). However, the efficiency of maintaining undifferentiated hESCs using human foreskin <em>fibroblast</em>-derived feeder layers is not as high as that from mouse feeder cells due to the lower level of secretion of Activin A(14). Obviously, there is an evident difference in <em>growth</em> <em>factor</em> production by mouse and human feeder cells. Analyses of the transcriptomes of mouse and human feeder cells revealed significant differences between supportive and non-supportive cells. Exogenous FGF2 is crucial for maintaining self-renewal of hESCs and hiPSCs, and has been identified as a key <em>factor</em> regulating the expression of Tgfβ1, Activin A and Gremlin (a BMP antagonist) in feeder cells. Activin A has been shown to induce the expression of OCT4, SOX2, and NANOG in hESCs(<em>15</em>-16). For long-term culture, hESCs and hiPSCs can be grown on mitotically inactivated MEFs or under feeder-free conditions in MEF-CM (MEF-Conditioned Medium) on Matrigel-coated plates to maintain their undifferentiated state. Success of both culture conditions fully depends on the quality of the feeder cells, since they directly affect the <em>growth</em> of hESCs. Here, we present an optimized method for the isolation and culture of mouse embryonic <em>fibroblasts</em> (MEFs), preparation of conditioned medium (CM) and enzyme-linked immunosorbent assay (ELISA) to assess the levels of Activin A within the media.

Bovine brain prostatropin is a potent and essential mitogen for prostate epithelial cell <em>growth</em>. The major form of prostatropin contains <em>15</em>4 amino acid residues in a single amino terminally blocked chain corresponding to a molecular weight of 17,400. The amino acid sequence of the <em>15</em>0 carboxy-terminal residues of prostatropin was derived by Edman degradation of overlapping peptides primarily generated by cleavage at lysyl and glutamyl residues. Analysis of the amino-terminal tetradecapeptide by fast atom bombardment mass spectrometry identified the blocking group as an acetyl moiety, and tandem mass spectrometry provided the sequence of the first 12 residues. Prostatropin residues <em>15</em>-<em>15</em>4 contain the sequence of bovine brain polypeptides recently described as acidic <em>fibroblast</em> <em>growth</em> <em>factor</em> and class I heparin-binding <em>growth</em> <em>factor</em>. The sequence of the first 25 residues of prostatropin is acetyl-Ala-(Gly, Glu)-Glu-Thr-Thr-Thr-Phe-Thr-Ala-Leu-Thr-Glu-Lys-Phe-Asn-Leu-Pro-Leu-Gly -Asn-Tyr-Lys-Lys-Pro. Reduced and carboxymethylated prostatropin exhibits mitogenic activity, suggesting that disulfide bonds among cysteine residues 30, 61, and 97 are not functionally essential. These results demonstrate by rigorous structural analysis that the brain-derived polypeptide previously described only as a mesenchymal and neuroectodermal cell mitogen is also an epithelial cell <em>growth</em> <em>factor</em> that may be involved in support of prostate hyperplasia and adenocarcinoma.

Versican is a member of the large aggregating chondroitin sulfate proteoglycan family. We have expressed in NIH3T3 <em>fibroblasts</em> a recombinant versican mini-gene comprising the G1 and G3 domains and <em>15</em>% of the CS domain. We observed that expression of the mini-versican gene stimulated cell proliferation as determined by cell counting and cell cycle analysis. Addition of exogenous mini-versican protein to cultured cells produced the same result. The effects of the mini-versican were greatly reduced when the G3 domain was deleted. Expression of the G3 domain alone promotes cell proliferation, and addition of purified G3 gene products to NIH3T3 <em>fibroblasts</em> and cultured chicken <em>fibroblasts</em> enhances cell <em>growth</em>. Further, deletion of the epidermal <em>growth</em> <em>factor</em> (EGF)-like motifs in the versican G3 domain reduced the effects of the mini-versican on cell proliferation. In the presence of the purified mini-versican protein, antisense oligonucleotides to the EGF receptor inhibited proliferation of NIH3T3 <em>fibroblasts</em>, compared with control sense oligonucleotides. Taken together, these results imply that versican enhances cell proliferation, and this effect is mediated, at least in part, by the action of versican EGF-like motifs on endogenous EGF receptor.

The organic anion-transporting polypeptide 1b family (Oatp1b2 in rodents and OATP1B1/1B3 in humans) is liver-specific and transports various chemicals into the liver. However, the role of the Oatp1b family in the hepatic uptake of bile acids (BAs) into the liver is unknown. Therefore, in Oatp1b2-null mice, the concentrations of BAs in plasma, liver, and bile were compared with wild-type (WT) mice. It was first determined that livers of the Oatp1b2-null mice were not compensated by altered expression of other hepatic transporters. However, the messenger RNA of Cyp7a1 was 70% lower in the Oatp1b2-null mice. Increased expression of <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>15</em> in intestines of Oatp1b2-null mice might be responsible for decreased hepatic expression of Cyp7a1 in Oatp1b2-null mice. The hepatic concentration and biliary excretion of conjugated and unconjugated BAs were essentially the same in Oatp1b2-null and WT mice. The serum concentration of taurine-conjugated BAs was essentially the same in the two genotypes. In contrast, the serum concentrations of unconjugated BAs were 3-45 times higher in Oatp1b2-null than WT mice. After intravenous administration of cholate to Oatp1b2-null mice, its clearance was 50% lower than in WT mice, but the clearance of taurocholate was similar in the two genotypes.

CONCLUSIONS

This study indicates that Oatp1b2 has a major role in the hepatic uptake of unconjugated BAs.

Elevation of intracellular cAMP has been associated with the suppression of macrophage activation. The present study has examined the effects of agents that alter intracellular levels of cAMP on LPS-induced macrophage gene expression. Treatment of murine peritoneal macrophages with trace amounts of LPS leads to dramatically enhanced expression of multiple mRNA including the competence genes JE and KC, first observed in platelet-derived <em>growth</em> <em>factor</em>-stimulated <em>fibroblasts</em>, and those encoding the inflammatory monokines IL-1 and TNF. If macrophages are first treated with cholera toxin or dibutyryl cAMP <em>15</em> min before stimulation with LPS, the accumulation of mRNA encoding both JE and TNF is strongly suppressed whereas mRNA levels for KC and IL-1 are unaffected. The suppression of JE and TNF mRNA levels is dose dependent, in the range of 10 to 500 microM dibutyryl cAMP; concentrations as high as 1 mM do not affect the expression of either KC or IL-1. When dibutyryl cAMP is added to macrophages after initiation of LPS treatment, suppressive effects are diminished in a time-dependent fashion. Furthermore, dibutyryl cAMP suppresses the LPS-induced transcriptional activation of the TNF gene. Previous work has shown that the LPS-induced expression of JE appears to be mediated by hydrolysis of polyphosphoinositides and involves a post-transcriptional mechanism. Treatment with dibutyryl cAMP suppresses JE expression induced by treatment with phorbol ester and A23187 suggesting that inhibition of gene expression must act at a site other than the initial transmembrane signaling event. Finally, dibutyryl cAMP only marginally affects the constitutive transcription of the JE gene indicating that suppression may involve a post-transcriptional mechanism. These results indicate that expression of genes encoding inducible early proteins and inflammatory monokines are selectively regulated by elevation of intracellular cAMP. Such effects may be pleiotropic in nature involving multiple molecular mechanisms.

Cytokines are a heterogenous group of polypeptide mediators that have been associated with activation of numerous functions, including the immune system and inflammatory responses. The cytokine families include, but are not limited to, interleukins (IL-I alpha, IL-I beta, ILIra and IL-2-IL-<em>15</em>), chemokines (IL-8/ NAP-I, NAP-2, MIP-I alpha and beta, MCAF/MCP-1, MGSA and RANTES), tumor necrosis <em>factors</em> (TNF-alpha and TNF-beta), interferons (INF-alpha, beta and gamma), colony stimulating <em>factors</em> (G-CSF, M-CSF, GM-CSF, IL-3 and some of the other ILs), <em>growth</em> <em>factors</em> (EGF, FGF, PDGF, TGF alpha, TGF beta and ECGF), neuropoietins (LIF, CNTF, OM and IL-6), and neurotrophins (BDNF, NGF, NT-3-NT-6 and GDNF). The neurotrophins represent a family of survival and differentiation <em>factors</em> that exert profound effects in the central and peripheral nervous system (PNS). The neurotrophins are currently under investigation as therapeutic agents for the treatment of neurodegenerative disorders and nerve injury either individually or in combination with other trophic <em>factors</em> such as ciliary neurotrophic <em>factor</em> (CNTF) or <em>fibroblast</em> <em>growth</em> <em>factor</em> (FGF). Responsiveness of neurons to a given neurotrophin is governed by the expression of two classes of cell surface receptor. For nerve <em>growth</em> <em>factor</em> (NGF), these are p75NTR (p75) and p140trk (referred to as trk or trkA), which binds both BDNF and neurotrophin (NT)-4/5, and trkC receptor, which binds only NT-3. After binding ligand, the neurotrophin-receptor complex is internalized and retrogradely transported in the axon to the soma. Both receptors undergo ligand-induced dimerization, which activates multiple signal transduction pathways. These include the ras-dependent pathway utilized by trk to mediate neurotrophin effects such as survival and differentiation. Indeed, cellular diversity in the nervous system evolves from the concerted processes of cell proliferation, differentiation, migration, survival, and synapse formation. Neural adhesion and extracellular matrix molecules have been shown to play crucial roles in axonal migration, guidance, and <em>growth</em> cone targeting. Proinflammatory cytokines, released by activated macrophages and monocytes during infection, can act on neural targets that control thermogenesis, behavior, and mood. In addition to induction of fever, cytokines induce other biological functions associated with the acute phase response, including hypophagia and sleep. Cytokine production has been detected within the central nervous system as a result of brain injury, following stab wound to the brain, during viral and bacterial infections (AIDS and meningitis), and in neurodegenerative processes (multiple sclerosis and Alzheimer's disease). Novel cytokine therapies, such as anticytokine antibodies or specific receptor antagonists acting on the cytokine network may provide an optimistic feature for treatment of multiple sclerosis and other diseases in which cytokines have been implicated.

Triple-negative [estrogen receptor (ER)-/progesterone receptor (PR)-/HER2-] breast cancers account for ~<em>15</em>% of overall breast cancers. Triple-negative breast cancers demonstrate a panel of specific molecular alterations including a high rate of p53 mutations, frequent loss of function of BRCA1, phosphatase and tensin homolog (PTEN) loss and a specific panel of tyrosine kinase activation [<em>fibroblast</em> <em>growth</em> <em>factor</em> receptor 2 (FGFR2)]. This molecular entity is considered as sensitive to chemotherapy in the adjuvant setting. When metastatic, the disease is usually aggressive and drug resistant, leading to cancer death within 18 months for the majority of patients. There is no evidence from randomized trials that triple-negative breast cancers have a different sensitivity to specific chemotherapy compared with other molecular classes. Similar findings have been reported for bevacizumab. Several recent research efforts have focused on this entity in the last few years. DNA alkylating agents have shown promising activity in the neoadjuvant setting, but no evidence from a phase III trial currently supports its use. Several targeted therapies are also being successfully developed. Poly(ADP ribose) polymerase 1 (PARP1) inhibitors induce tumor response as a single agent in BRCA1-mutated breast cancer, and could sensitize cisplatin in the whole triple negative population. Several other targeted agents are being developed in this setting, including epidermal <em>growth</em> <em>factor</em> receptor (EGFR), FGFR2, mammalian target of rapamycin (mTOR) and NOTCH inhibitors.

OBJECTIVE

Fibroblast growth factor receptor 3 (FGFR3) mutations have been associated with achondroplastic syndromes and urinary bladder carcinomas. Here we describe changes in FGFR3 mRNA and protein expression in transitional carcinomas and determine the effect of monoclonal antibodies against FGFR3 in RT-112 cell line proliferation.

METHODS

We used microarray tools to evaluate FGFR3 mRNA expression in 22 urinary bladder carcinomas at different stages (noninvasive pTa, lamina propria invasive pT1, and muscular invasive pT2) and 7 nonneoplastic tissue controls. FGFR3 protein expression was evaluated by Western blotting in 15 different carcinomas and 3 nonneoplastic controls. Two hundred thirty-seven urinary bladder and renal pelvis carcinomas and 21 negative controls were tested on tissue microarrays by immunohistochemistry. The effect on cell proliferation in the RT-112 bladder cancer cell line of monoclonal antibodies against FGFR3 was also evaluated.

RESULTS

Overexpression of FGFR3 mRNA was found in pTa and pT1 stage carcinomas (fold change >8) and in pT2 carcinomas (fold change >4). Nonneoplastic urinary bladder samples do not express FGFR3 protein. However, 83% of pTa, 100% of pT1, and 50% of pT2 carcinomas expressed FGFR3 as determined by Western blotting. By immunohistochemistry, FGFR3 was positive in 71.4% of pTa, 72% of pT1, and 49.2% of pT2 cases as well as 61.5% of upper urinary tract carcinomas. Proliferation of the RT-112 cell line was inhibited with monoclonal antibodies against FGFR3.

CONCLUSIONS

FGFR3 seems to play an important role in transitional cell carcinoma development. Our results suggest that FGFR3 antagonists could be developed as possible therapeutics for treatment of urinary tract carcinoma.

Bone marrow mesenchymal stem cells (BMMSCs) have the capacity for self-renewal, and differentiation into a variety of cell types. They thus represent an attractive source of material for cell therapy. However, little is known about the mechanisms underlying the proliferation of BMMSCs. The purpose of this study was to identify the <em>factors</em> and signaling pathways involved in the proliferation of stem cell antigen-1(+) (Sca-1(+)) BMMSCs. Among the cytokines and <em>growth</em> <em>factors</em> examined in this study, <em>fibroblast</em> <em>growth</em> <em>factor</em>-2 (FGF-2) and FGF-4 significantly stimulated the proliferation of Sca-1(+) BMMSCs, as determined by bromodeoxyuridine incorporation. PI3K-Akt, ERK1/2, and JAK/STAT3 pathways were investigated after stimulation with FGF-2 or FGF-4 via Western blot analysis. No changes were observed in the total ERK1/2 and Akt; however, the pERK1/2 and pAkt levels were upregulated early within <em>15</em> min in the FGF-2- or FGF-4-treated Sca-1(+) BMMSCs. Moreover, the pERK1/2 and pAkt upregulation induced by FGF-2 and -4 were completely abolished by treatment with the MEK1/2 inhibitor, U0126 and the PI3K inhibitor, LY294002. However, no change in pJAK2 or total JAK2 levels was observed in the Sca-1(+) BMMSCs induced by FGF-2 or FGF-4. As a consequence of PI3K-Akt and ERK1/2, the upregulation of c-Jun in the Sca-1(+) BMMSCs, after stimulation with FGF-2 or FGF-4, was observed after 12 and 24 h. Moreover, the activation of c-Jun in FGF-2- and FGF-4-treated Sca-1(+) BMMSCs was significantly reduced by U0126. Taken together, these data suggest that FGF-2 and -4 promote the proliferation of Sca-1(+) BMMSCs by activation of the ERK1/2 and PI3K-Akt signaling pathways.

The present study was performed to compare serum concentrations of maternal and fetal angiogenic <em>growth</em> <em>factors</em> in IUGR (intrauterine <em>growth</em> restriction) and normal pregnancy at the time of delivery. VEGF (vascular endothelial <em>growth</em> <em>factor</em>), PlGF (placental <em>growth</em> <em>factor</em>), sFlt-1 (soluble fms-like tyrosine kinase 1), sKDR (soluble kinase domain receptor) and bFGF (basic <em>fibroblast</em> <em>growth</em> <em>factor</em>) were measured by ELISA in serum from a maternal peripheral vein, the umbilical vein and the umbilical arteries in <em>15</em> women with pregnancies complicated by IUGR and 16 controls (women with normal pregnancies). In IUGR, sFlt-1 was increased, and PlGF and sKDR were decreased, in both maternal serum and serum from the umbilical vein. Additionally, bFGF was increased in serum from the umbilical vein of women with pregnancies complicated by IUGR. No significant differences in <em>growth</em> <em>factor</em> concentrations between the groups were found in serum from the umbilical artery. In both groups, levels of VEGF were higher and levels of sFlt-1 were lower in serum from the umbilical vein and umbilical artery compared with maternal serum. PlGF levels were found to be lower in serum from the umbilical vein compared with maternal serum in both groups, whereas PlGF levels in serum from the umbilical artery were significantly lower only in the control group. These findings suggest an imbalance of angiogenic and anti-angiogenic <em>factors</em> in IUGR, with formation of an anti-angiogenic state in maternal and, to a lesser extent, umbilical vein blood. The placenta appears to play a central role in the release of sFlt-1 into maternal and umbilical blood. Umbilical artery blood was unaffected in IUGR, indicating that the fetus does not contribute to changes in angiogenic <em>growth</em> <em>factor</em> concentrations.

Bile acid malabsorption, which in patients leads to excessive fecal bile acid excretion and diarrhea, is characterized by a vicious cycle in which the feedback regulation of bile acid synthesis is interrupted, resulting in additional bile acid production. Feedback regulation of bile acid synthesis is under the control of an endocrine pathway wherein activation of the nuclear bile acid receptor, farnesoid X receptor (FXR), induces enteric expression of the hormone, <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>15</em> (FGF<em>15</em>). In liver, FGF<em>15</em> acts together with FXR-mediated expression of small heterodimer partner to repress bile acid synthesis. Here, we show that the FXR-FGF<em>15</em> pathway is disrupted in mice lacking apical ileal bile acid transporter, a model of bile acid malabsorption. Treatment of Asbt-/- mice with either a synthetic FXR agonist or FGF<em>15</em> downregulates hepatic cholesterol 7alpha-hydroxylase mRNA levels, decreases bile acid pool size, and reduces fecal bile acid excretion. These findings suggest that FXR agonists or FGF<em>15</em> could be used therapeutically to interrupt the cycle of excessive bile acid production in patients with bile acid malabsorption.

The first intron of the human alpha 1(I) collagen gene contains a negatively acting element that inhibits transcription of the chloramphenicol acetyltransferase gene driven by either a collagen or an SV40 basal promoter (Bornstein, P., McKay, J., Morishima, J., Devarayalu, S., and Gelinas, R. E. (1987) Proc. Natl. Acad. Sci. U. S. A. 84, in press). We now find that this element is flanked by sequences that both neutralize the inhibitory effect and impart a net positive effect on transcription. A collagen-human <em>growth</em> hormone minigene was constructed in which varying lengths of the collagen intron were retained. Plasmids were transfected into chick tendon <em>fibroblasts</em>, and transcriptional activity was measured by solution hybridization with an antisense RNA probe. The presence of the intact intronic sequence stimulated transcription by a <em>factor</em> of 2-3-fold in comparison with intron-deleted plasmids. However, the isolated negatively acting element inhibited transcription by a <em>factor</em> of <em>15</em>-20-fold. Surprisingly, this effect was markedly orientation-dependent. Intronic segments flanking the negatively acting element stimulated transcription both when cloned 5' to the collagen promoter in chloramphenicol acetyltransferase-based plasmids and 3' in collagen-human <em>growth</em> hormone constructions. We conclude that expression of the alpha 1(I) collagen gene is controlled by several intronic elements that function coordinately with 5'-flanking and promoter elements.

Controlled long-term delivery of basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF) could be used as an angiogenesis therapy. In this study, novel heparin-conjugated poly(L-lactide-co-glycolide) (PLGA) nanospheres (HCPNs) were developed for long-term, zero-order delivery of bFGF. HCPNs were prepared by using a coupling reaction between amino-terminated PLGA nanospheres and heparin in the presence of 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide. The amount of heparin conjugated to the PLGA nanospheres was increased up to 29-fold by using nanospheres made from lower molecular weight PLGA, or star-shaped PLGA, as compared to nanospheres made from higher molecular weight PLGA, or linear PLGA. The release of bFGF from HCPNs was sustained for 3 weeks with no initial burst release. The bFGF release period was increased to more than 4 weeks using a delivery system of HCPNs suspended in fibrin gel. The release was nearly zero order. The rate of bFGF release from HCPNs in fibrin gel was controlled by the fibrinogen concentration in the fibrin gel. As the fibrinogen concentration increased, the bFGF release rate decreased. The bioactivity of bFGF released from HCPNs in fibrin gel was assessed using human umbilical vein endothelial cell (HUVEC) culture. bFGF released from HCPNs in fibrin gel exhibited HUVEC <em>growth</em> for <em>15</em> days, similar to that of cultures to which bFGF in free form was added daily, suggesting that the delivery system of HCPNs in fibrin gel can release bFGF in a bioactive form for a long period. The therapeutic potential of bFGF delivery using HCPNs in fibrin gel was investigated in a mouse limb ischemia model. Immunohistological analysis of mouse ischemic limbs indicated that the microvessel density was much higher in the ischemic limbs treated with bFGF delivery using HCPNs in fibrin gel than in the ischemic limbs treated with daily injections of bFGF or with bFGF delivery using fibrin gel. This study shows that a bFGF delivery system using HCPNs in fibrin gel exhibits controllable, long-term, zero-order release of bFGF and potentiates the angiogenic efficacy of bFGF administration.

The production of transgenic and null mice with skin abnormalities makes it increasingly important to establish cultures of mouse epidermal keratinocytes for in vitro studies. This requires that each cell line be derived from a single mouse and that the cells be carried for multiple passages. Freezing the cells would also be advantageous by allowing comparison of keratinocytes from several mouse lines at the same time. Mouse keratinocytes, however, have been exceedingly difficult to grow as primary cultures, and subculturing these cells has been virtually impossible until now. We describe a gentle dissociation method and a highly supplemented <em>fibroblast</em> conditioned medium that allows us to grow and subculture total mouse keratinocytes for up to 19 subcultures, allowing an increase in cell number of greater than 10 logs. Epidermal keratinocytes from newborn mice were grown on collagen IV coated dishes in murine <em>fibroblast</em> conditioned medium with 0.06 mM calcium and added <em>growth</em> <em>factors</em>. The cells could be passaged, frozen as viable stocks, and induced to differentiate. Morphologically the cultured keratinocytes demonstrated a pattern characteristic of basal cells. Stratified cultures which made mouse keratin 1 and profilaggrin through passage 10 were induced by purging the monolayer cultures of <em>growth</em> <em>factors</em>, then adding medium with 0.<em>15</em> mM calcium; expression of mouse keratin 1 and profilaggrin was lost by passage <em>15</em>. The methods explained in detail here should be of great interest to investigators who are now trying to analyze skin phenotypes and expression of markers of epidermal differentiation of their transgenic or knockout mice.

OBJECTIVE

Fibroblast growth factor (FGF) 21, a hormone primarily secreted by liver, has recently been shown to have beneficial effects on glucose and lipid metabolism and insulin sensitivity in animal models. This study investigated the association of serum FGF21 levels with insulin secretion and sensitivity, as well as circulating parameters of lipid metabolism and hepatic enzymes in Chinese subjects.

METHODS

Serum FGF21 levels were determined by ELISA in 134 normal glucose tolerance (NGT), 101 isolated-impaired fasting glucose, and 118 isolated-impaired glucose tolerance (I-IGT) Chinese subjects, and their association with parameters of adiposity, glucose, and lipid profiles, and levels of liver injury markers was studied. In a subgroup of this study, the hyperglycemic clamp technique was performed in 31 NGT, 17 isolated-impaired fasting glucose, and 15 I-IGT subjects to measure insulin secretion and sensitivity to test the associations with serum FGF21.

RESULTS

The serum FGF21 levels in I-IGT were significantly higher than NGT subjects [164.6 pg/ml (89.7, 261.0) vs. 111.8 pg/ml (58.0, 198.9); P < 0.05], and correlated positively with several parameters of adiposity. Multiple stepwise regression analysis showed an independent association of serum FGF21 with serum triglycerides, total cholesterol, and gamma-glutamyltransferase (all P < 0.05). However, FGF21 did not correlate with insulin secretion and sensitivity, as measured by hyperglycemic clamp and a 75-g oral glucose tolerance test.

CONCLUSIONS

Serum levels of FGF21 are closely related to adiposity, lipid metabolism, and biomarkers of liver injury but not insulin secretion and sensitivity in humans.

Pulmonary fibrosis is a progressive scarring disease with no effective treatment. Transforming <em>growth</em> <em>factor</em> (TGF)-beta is up-regulated in fibrotic diseases, where it stimulates differentiation of <em>fibroblasts</em> to myo<em>fibroblasts</em> and production of excess extracellular matrix. Peroxisome proliferator-activated receptor (PPAR) gamma is a transcription <em>factor</em> that regulates adipogenesis, insulin sensitization, and inflammation. We report here that a novel PPARgamma ligand, 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO), is a potent inhibitor of TGF-beta-stimulated differentiation of human lung <em>fibroblasts</em> to myo<em>fibroblasts</em>, and suppresses up-regulation of alpha-smooth muscle actin, fibronectin, collagen, and the novel myofibroblast marker, calponin. The inhibitory concentration causing a 50% decrease in aSMA for CDDO was 20-fold lower than the endogenous PPARgamma ligand, <em>15</em>-deoxy-Delta(12,14)-prostaglandin J(2) (<em>15</em> d-PGJ(2)), and 400-fold lower than the synthetic ligand, rosiglitazone. Pharmacologic and genetic approaches were used to demonstrate that CDDO mediates its activity via a PPARgamma-independent pathway. CDDO and <em>15</em> d-PGJ(2) contain an alpha/beta unsaturated ketone, which acts as an electrophilic center that can form covalent bonds with cellular proteins. Prostaglandin A(1) and diphenyl diselenide, both strong electrophiles, also inhibit myofibroblast differentiation, but a structural analog of <em>15</em> d-PGJ(2) lacking the electrophilic center is much less potent. CDDO does not alter TGF-beta-induced Smad or AP-1 signaling, but does inhibit acetylation of CREB binding protein/p300, a critical coactivator in the transcriptional regulation of TGF-beta-responsive genes. Overall, these data indicate that certain PPARgamma ligands, and other small molecules with electrophilic centers, are potent inhibitors of critical TGF-beta-mediated profibrogenic activities through pathways independent of PPARgamma. As the inhibitory concentration causing a 50% decrease in aSMA for CDDO is 400-fold lower than that in rosiglitazone, the translational potential of CDDO for treatment of fibrotic diseases is high.

OBJECTIVE

We studied the safety and effectiveness of TSU-68, an oral tyrosine kinase inhibitor of vascular endothelial growth factor receptor-2, platelet-derived growth factor receptor and fibroblast growth factor receptor, in patients with advanced hepatocellular carcinoma (HCC).

METHODS

Patients with unresectable or metastatic HCC were eligible for enrollment. In phase I, the safety, tolerability and pharmacokinetics were assessed in patients stratified based on liver function, from no cirrhosis to Child-Pugh class B. The safety and effectiveness were assessed in phase II at the dose determined in phase I.

RESULTS

Twelve patients were enrolled in phase I. Dose-limiting toxicities were found with TSU-68 at the dose of 400 mg bid in Child-Pugh B patients, and 200 mg bid was established as the phase II dose. Phase II included 23 additional patients, and the safety and efficacy were evaluated in a total of 35 patients. One patient (2.9%) had a complete response. Two patients (5.7%) had a partial response, and 15 patients (42.8%) showed a stable disease. The median time to progression was 2.1 months, and the median overall survival was 13.1 months. Common adverse events were hypoalbuminemia, diarrhea, anorexia, abdominal pain, malaise, edema and AST/ALT elevation. The analysis of angiogenesis-related parameters suggests that serum-soluble vascular cell adhesion molecule-1 is a possible marker to show the response.

CONCLUSIONS

TSU-68 at a dose of 200 mg bid determined by stratification into liver function, showed promising preliminary efficacy with a high safety profile in patients with HCC who had been heavily pre-treated.

Vitamin D is a potent stimulator of monocyte innate immunity, and this effect is mediated via intracrine conversion of 25-hydroxyvitamin D (25OHD) to 1,25-dihydroxyvitamin D (1,25(OH)(2) D). In the kidney, synthesis of 1,25(OH)(2) D is suppressed by <em>fibroblast</em> <em>growth</em> <em>factor</em> 23 (FGF23), via transcriptional suppression of the vitamin D-activating enzyme 1α-hydroxylase (CYP27B1). We hypothesized that FGF23 also suppresses CYP27B1 in monocytes, with concomitant effects on intracrine responses to 1,25(OH)(2) D. Healthy donor peripheral blood mononuclear cell monocytes (PBMCm) and peritoneal dialysate monocyte (PDm) effluent from kidney disease patients were assessed at baseline to confirm the presence of mRNA for FGF23 receptors (FGFRs), with Klotho and FGFR1 being more strongly expressed than FGFR2/3/4 in both cell types. Immunohistochemistry showed coexpression of Klotho and FGFR1 in PBMCm and PDm, with this effect being enhanced following treatment with FGF23 in PBMCm but not PDm. Treatment with FGF23 activated mitogen-activated protein kinase (MAPK) and protein kinase B (Akt) pathways in PBMCm, demonstrating functional FGFR signaling in these cells. FGF23 treatment of PBMCm and PDm decreased expression of mRNA for CYP27B1. In PBMCm this was associated with downregulation of 25OHD to 1,25(OH)(2) D metabolism, and concomitant suppression of intracrine induced 24-hydroxylase (CYP24A1) and antibacterial cathelicidin (LL37). FGF23 suppression of CYP27B1 was particularly pronounced in PBMCm treated with interleukin-<em>15</em> to stimulate synthesis of 1,25(OH)(2) D. These data indicate that FGF23 can inhibit extra-renal expression of CYP27B1 and subsequent intracrine responses to 1,25(OH)(2) D in two different human monocyte models. Elevated expression of FGF23 may therefore play a crucial role in defining immune responses to vitamin D and this, in turn, may be a key determinant of infection in patients with chronic kidney disease (CKD).

In vitro and in vivo studies provide evidence that a variety of <em>growth</em> <em>factors</em> and cytokines are actively secreted by muscle tissue. Muscle can therefore function as an endocrine and paracrine organ. These peptides characterize the muscle secretome, and many muscle-derived <em>factors</em> such as insulin-like <em>growth</em> <em>factor</em>-1, basic <em>fibroblast</em> <em>growth</em> <em>factor</em>, interleukin-<em>15</em>, myostatin and secreted protein acidic and rich in cysteine (osteonectin) are also known to have significant effects on bone metabolism. The <em>factors</em> secreted by muscle may vary according to muscle activity, in that muscle contraction, muscle atrophy or traumatic muscle injury can alter the type and relative abundance of particular <em>factors</em> released from muscle cells. The molecular and cellular pathways by which muscle-derived <em>factors</em> affect different types of bone cells (for example, osteoblasts, osteoclasts and osteocytes) are, however, poorly understood. Nevertheless, these findings further underscore the complex nature of muscle-bone interactions, and highlight the importance of integrating muscle biology and physiology into our understanding of bone <em>growth</em>, development and aging.

The <em>fibroblast</em> <em>growth</em> <em>factor</em> receptor 2 gene contains a pair of mutually exclusive alternative exons, one of which (K-SAM) is spliced specifically in epithelial cells. We have described previously (F. Del Gatto and R. Breathnach, Mol. Cell. Biol. <em>15</em>:4825-4834, 1995) some elements controlling K-SAM exon splicing, namely weak exon splice sites, an exon-repressing sequence, and an intron-activating sequence. We identify here two additional sequences in the intron downstream from the K-SAM exon which activate splicing of the exon. The first sequence (intron-activating sequence 2 [IAS2]) lies 168 to 186 nucleotides downstream from the exon's 5' splice site. The second sequence (intron-activating sequence 3 [IAS3]) lies 933 to 1,052 nucleotides downstream from the exon's 5' splice site. IAS3 is a complex region composed of several parts, one of which (nucleotides 963 to 983) can potentially form an RNA secondary structure with IAS2. This structure is composed of two stems separated by an asymmetric bulge. Mutations which disrupt either stem decrease activation, while compensatory mutations which reestablish the stem restore activation, either completely or partially, depending on the mutation. We present a model for K-SAM exon splicing involving the intervention of multiple, interdependent pre-mRNA sequence elements.

Gene amplification is an important mechanism of oncogene activation in breast and other cancers. Characterization of amplified regions of the genome in breast cancer has led to the identification of important oncogenes including erbB-2/HER-2, C-MYC, and <em>fibroblast</em> <em>growth</em> <em>factor</em> receptor (FGFR) 2. Chromosome 8p11-p12 is amplified in 10-<em>15</em>% of human breast cancers. The putative oncogene FGFR1 localizes to this region; however, we show evidence that FGFR inhibition fails to slow <em>growth</em> of three breast cancer cell lines with 8p11-p12 amplification. We present a detailed analysis of this amplicon in three human breast cancer cell lines using comparative genomic hybridization, traditional Southern and Northern analysis, and chromosome 8 cDNA microarray expression profiling. This study has identified new candidate oncogenes within the 8p11-p12 region, supporting the hypothesis that genes other than FGFR1 may contribute to oncogenesis in breast cancers with proximal 8p amplification.

The <em>fibroblast</em> <em>growth</em> <em>factor</em>-receptor 3 (FGFR3) Lys650 codon is located within a critical region of the tyrosine kinase-domain activation loop. Two missense mutations in this codon are known to result in strong constitutive activation of the FGFR3 tyrosine kinase and cause three different skeletal dysplasia syndromes-thanatophoric dysplasia type II (TD2) (A1948G [Lys650Glu]) and SADDAN (severe achondroplasia with developmental delay and acanthosis nigricans) syndrome and thanatophoric dysplasia type I (TD1) (both due to A1949T [Lys650Met]). Other mutations within the FGFR3 tyrosine kinase domain (e.g., C1620A or C1620G [both resulting in Asn540Lys]) are known to cause hypochondroplasia, a relatively common but milder skeletal dysplasia. In 90 individuals with suspected clinical diagnoses of hypochondroplasia who do not have Asn540Lys mutations, we screened for mutations, in FGFR3 exon <em>15</em>, that would disrupt a unique BbsI restriction site that includes the Lys650 codon. We report here the discovery of three novel mutations (G1950T and G1950C [both resulting in Lys650Asn] and A1948C [Lys650Gln]) occurring in six individuals from five families. Several physical and radiological features of these individuals were significantly milder than those in individuals with the Asn540Lys mutations. The Lys650Asn/Gln mutations result in constitutive activation of the FGFR3 tyrosine kinase but to a lesser degree than that observed with the Lys540Glu and Lys650Met mutations. These results demonstrate that different amino acid substitutions at the FGFR3 Lys650 codon can result in several different skeletal dysplasia phenotypes.