Targeted Therapies in Non-Small Cell Lung Cancer-Beyond EGFR and ALK

Systemic therapy for non-small cell lung cancer (NSCLC) has undergone a dramatic paradigm shift over the past decade. Advances in our understanding of the underlying biology of NSCLC have revealed distinct molecular subtypes. A substantial proportion of NSCLC depends on oncogenic molecular aberrations (so-called "driver mutations") for their malignant phenotype. Personalized therapy encompasses the strategy of matching these subtypes with effective targeted therapies. EGFR mutations and ALK translocation are the most effectively targeted oncogenes in NSCLC. EGFR mutations and ALK gene rearrangements are successfully being targeted with specific tyrosine kinase inhibitors. The number of molecular subgroups of NSCLC continues to grow. The scope of this review is to discuss recent data on novel molecular targets as ROS1, BRAF, KRAS, HER2, c-MET, RET, PIK3CA, FGFR1 and DDR2. Thereby the review will focus on therapeutic strategies targeting these aberrations. Moreover, the emerging challenge of acquired resistance to initially effective therapies will be discussed.

Activated cdc42-associated kinase is up-regulated in non-small-cell lung cancer and necessary for FGFR-mediated AKT activation

Activated cdc42-associated tyrosine kinase 1 (ACK1) has been reported to be implicated in non-small-cell lung cancer (NSCLC). However, the expression pattern and biological functions of ACK1 in the progression of NSCLC are not fully understood. In this study, it was found that the expression of ACK1 was significantly up-regulated in NSCLC samples compared to their adjacent normal tissues. Meanwhile, the expression of ACK1 was inversely correlated with the survival of NSCLC patients. Moreover, in the biological function studies, ACK1 was further validated to promote the growth, migration, and metastasis of NSCLC cells in vitro and in vivo. Mechanistically, ACK1 bind with FGFR1 and was essential for the phosphorylation of AKT induced by FGF. Our study demonstrated that ACK1 played an oncogenic role in the progression of NSCLC and ACK1 might be a promising target for the treatment of NSCLC.

Myeloid and lymphoid neoplasm with abnormalities of FGFR1 presenting with trilineage blasts and RUNX1 rearrangement: a case report and review of literature

OBJECTIVES

Myeloid and lymphoid neoplasms with abnormalities of fibroblast growth factor receptor 1 gene (FGFR1) are a rare and aggressive disease group that harbors translocations of FGFR1 with at least 14 recognized partner genes. We report a case of a patient with a novel t(17;21)(p13;q22) with RUNX1 rearrangement and trilineage blasts.

METHODS

A 29-year-old man with relapsed T-lymphoblastic lymphoma in the cervical nodes showed a myeloproliferative neoplasm in his bone marrow with three separate populations of immunophenotypically aberrant myeloid, T-lymphoid, and B-lymphoid blasts by flow cytometry. Cytogenetic and fluorescent in situ hybridization studies showed unique dual translocations of t(8;13)(p11.2;q12) and t(17;21)(p13;q22) with RUNX1 rearrangement.

RESULTS

The patient was initiated on a mitoxantrone, etoposide, and cytarabine chemotherapy regimen and died of complications of disease 1 month later.

CONCLUSIONS

To our knowledge, this is the first reported case of a myeloid and lymphoid neoplasm with abnormalities of FGFR1 with t(17;21)(p13;q22) and trilineage blasts.

Copy number gains of FGFR1 and 3q chromosome in squamous cell carcinoma of the lung

Squamous cell carcinoma of the lung (SQCCL) remains a leading cause of cancer-related death. Unlike non-smoker adenocarcinoma of the lung, where highly efficient tyrosine kinase inhibitors are available for treating mutant EGFR or ALK-rearranged, no targetable biomarkers are available for SQCCL. The frequent and focal amplification of FGFR1 has generated great expectations in offering new therapeutical options in case of 16-22% of SQCCL patients. Broad 3q chromosome amplification is widely recognized as the most common chromosomal aberration found in SQCCL, where PIK3CA, SOX2, ACK1, PRKCI, TP63, PLD1, ECT2, and others genes are located. Although SOX2 has been postulated as a key regulator of basal stem cells transformation and tumor progression, it seems to confer a good prognosis in SQCCL. It is known that each patient might carry a different length of 3q chromosome amplicon. Thus, we suggest that the number and the biological importance of the genes spanned along each patient's 3q amplicon might help to explain inter-individual outcome variations of the disease and its potential predictive value, especially when relevant oncogenes such as those mentioned above are implicated. Currently, there is no clinical predictive data available from clinical trials. In this review, we have focused on the potential role of FGFR1 in SQCCL prognosis. Additionally, we have explored recently available public data on the comprehensive genomic characterization of SQCCL, in relation to the protein-coding genes that have a strong gene copy number - mRNA correlation in 3q chromosome, that were previously described as potential driver oncogenes or its modifiers in SQCCL.

The frequency and impact of FGFR1 amplification on clinical outcomes in Korean patients with small cell lung cancer

OBJECTIVES

Fibroblast growth factor receptor 1 (FGFR1) plays a critical role in many human cancers. We tried to identify the frequency of FGFR1 amplifications among Korean patients with small cell lung cancer (SCLC). Additionally, we examined the clinical significance of FGFR1 amplifications for overall survival (OS) and progression-free survival (PFS) among SCLC patients who received standard chemotherapies.

MATERIALS AND METHODS

Tumor tissues from 158 Korean patients diagnosed with SCLC from September 2009 to February 2013 were collected and analyzed using an FGFR1 FISH assay with a probe that hybridized to chromosome region 8p12-8p11.23 (Abbott Molecular, Abbott Park, IL).

RESULTS AND CONCLUSION

FGFR1 amplification was detected in three patients (1.9%) harboring extensive disease (ED). A multivariate analysis showed that among the patients with ED, FGFR1 amplification was associated with shorter disease-free survival to first-line chemotherapy with etoposide plus cisplatin or carboplatin (hazard ratio [HR]=7.1; 95% confidence interval [CI]=2.0-25.4; P=0.003). The median overall survival time of the patients with ED was 8.2 and 10.2 months among patients with and without FGFR1 amplification, respectively (P=0.37). Although FGFR1 amplification is rare in SCLC compared to non-small cell lung cancer or other malignancies with squamous histology, it is associated with poor survival following standard chemotherapy in SCLC. Further studies in large cohorts of patients with SCLC are needed to verify these results. Our results imply that FGFR1 may be a potential therapeutic target in SCLC and it could be confirmed in a clinical trial.

Synthesis and evaluation of biological and antitumor activities of 5,7-dimethyl- oxazolo[5,4-d]pyrimidine-4,6(5H,7H)-dione derivatives as novel inhibitors of FGFR1

A series of 5,7-dimethyl-oxazolo[5,4-d]pyrimidine-4,6(5H,7H)-dione derivatives, N5a-5l, was designed, synthesized and evaluated for their FGFR1-inhibition ability as well as cytotoxicity against three cancer cell lines (H460, B16F10 and A549) in vitro. Several compounds displayed good-to-excellent potency against these cancer cell lines compared to SU5402. Structure-activity relationship analyses indicated that compounds with a rigid structure and more heteroatoms at the side chain of the parent ring were more effective than those without these substitutions. The compound N5g (37.4% FGFR1 inhibition at 1.0 μM) was identified to have the most potent antitumor activities, with IC50 values of 5.472, 4.260 and 5.837 μM against H460, B16F10 and A549 cell lines, respectively. Together, our results suggest that 5,7-dimethyl-oxazolo[5,4-d]pyrimidine-4,6(5H,7H)-dione derivatives may serve as potential agents for the treatment of FGFR1-mediated cancers.

Fibroblast Growth Factor 21 Analogs for Treating Metabolic Disorders

Fibroblast growth factor (FGF) 21 is a member of the endocrine FGF subfamily. FGF21 expression is induced under different disease conditions, such as type 2 diabetes, obesity, chronic kidney diseases, and cardiovascular diseases, and it has a broad spectrum of functions in regulating various metabolic parameters. Many different approaches have been pursued targeting FGF21 and its receptors to develop therapeutics for treating type 2 diabetes and other aspects of metabolic conditions. In this article, we summarize some of these key approaches and highlight the potential challenges in the development of these agents.

Selection of Antibodies Interfering with Cell Surface Receptor Signaling Using Embryonic Stem Cell Differentiation

Antibodies able to bind and modify the function of cell surface signaling components in vivo are increasingly being used as therapeutic drugs. The identification of such "functional" antibodies from within large antibody pools is, therefore, the subject of intense research. Here we describe a novel cell-based expression and reporting system for the identification of functional antibodies from antigen-binding populations preselected with phage display. The system involves inducible expression of the antibody gene population from the Rosa-26 locus of embryonic stem (ES) cells, followed by secretion of the antibodies during ES cell differentiation. Target antigens are cell-surface signaling components (receptors or ligands) with a known effect on the direction of cell differentiation (FGFR1 mediating ES cell exit from self renewal in this particular protocol). Therefore, inhibition or activation of these components by functional antibodies in a few elite clones causes a shift in the differentiation outcomes of these clones, leading to their phenotypic selection. Functional antibody genes are then recovered from positive clones and used to produce the purified antibodies, which can be tested for their ability to affect cell fates exogenously. Identified functional antibody genes can be further introduced in different stem cell types. Inducible expression of functional antibodies has a temporally controlled protein-knockdown capability, which can be used to study the unknown role of the signaling pathway in different developmental contexts. Moreover, it provides a means for control of stem cell differentiation with potential in vivo applications.

Increased expression of fibroblast growth factor receptor 1 in endometriosis and its correlation with endometriosis-related dysmenorrhea and recurrence

OBJECTIVE(S)

This study aims to identify a critical molecule that potentially participates in endometriosis pathogenesis and characterize its correlation with dysmenorrhea and recurrence.

STUDY DESIGN

We utilized a bioinformatics-based strategy to screen for candidate genes and fibroblast growth factor receptor 1(FGFR1) was chosen for further validation. FGFR1 expression was examined in specimens of ectopic and eutopic endometrium obtained from 48 patients with endometriosis and specimens of eutopic endometrium from 26 healthy control subjects using immunohistochemistry and Western blotting. In addition, FGFR shRNA treatment was applied in a nude mice endometriosis model to examine the functional role of FGFR1 in endometriosis formation in vivo.

RESULTS

FGFR1 was found commonly overexpressed in ectopic endometrium of endometriosis compared with either its eutopic counterpart or endometrium from normal patients (P < 0.05). FGFR shRNA treatment impaired endometriosis formation and alleviated endometriosis-related symptoms in vivo. FGFR1 expression in ectopic endometrium was correlated with dysmenorrhea severity (P < 0.05) and recurrence in endometriosis patients (P < 0.05).

CONCLUSION(S)

FGFR1 might be involved in endometriosis development, which could possibly serve as a novel therapeutic target and prognostic marker for this disease.

FGFR1 as a novel prognostic and predictive biomarker in squamous cell cancers of the lung and the head and neck area

FGFR1 amplification is a genomic aberration recently identified in various types of cancer. Especially squamous cell carcinomas of the lung and the head and neck show this genetic alteration in high frequencies. In these cancers FGFR1 is not only a therapeutic target but does also serve as a biomarker that correlates with parameters of worse outcome. However, since FGFR1 amplification does not always correlate with high protein expression defining the best predictive biomarker for a FGFR1 targeted therapy is of great importance.

MicroRNA-34a negatively regulates anesthesia-induced hippocampal apoptosis and memory impairment through FGFR1

BACKGROUND

Mounting evidence has shown the toxic effects of anesthesia to neonatal hippocampus. We used an in vivo mouse model to explore the role of microRNA 34a (miR-34a) in regulating anesthesia-induced hippocampal neurotoxicity.

METHODS

One-month old C57/BL6 mice received daily intraperitoneal injection of anesthesia (ketamine, 50 mg/kg) for 7 days. One day after, apoptosis was evaluated by TUNEL staining in hippocampal CA1 region, and expression level of miR-34a assessed by real-time quantitative PCR (qPCR). Hippocampal miR-34a was then down-regulated through lentivirus mediated cortical injection prior to anesthesia. The effects of inhibiting hippocampal miR-34a on anesthesia-induced hippocampal apoptosis and memory impairment were further investigated by TUNEL staining and Morris water maze (MWM) test. The predicted molecular target of miR-34a, fibroblast growth factor receptor 1 (FGFR1) was down-regulated in hippocampus through siRNA-mediated cortical injection and its effect on hippocampal apoptosis was also examined.

RESULTS

Anesthesia caused severe apoptosis among hippocampal CA1 neurons and upregulated hippocampal miR-34a. On the other hand, lentivirual inhibition of miR-34a protected anesthesia-induced hippocampal apoptosis and memory impairment. Luciferase essay demonstrated FGFR1 was directly regulated by miR-34a in hippocampus. siRNA-induced FGFR1 downregulation further exaggerated anesthesia-induced apoptosis in hippocampus.

CONCLUSIONS

Overall, we showed that miR-34a negatively modulated anesthesia-induced hippocampal neurotoxicity.

Deletion of Fgfr1 in osteoblasts enhances mobilization of EPCs into peripheral blood in a mouse endotoxemia model

Endothelial progenitor cells (EPCs) contribute to neovascularization and vascular repair, and may exert a beneficial effect on the clinical outcome of sepsis. Osteoblasts act as a component of "niche" in bone marrow, which provides a nest for stem/progenitor cells and are involved in the formation and maintenance of stem/progenitor cells. Fibroblast growth factor receptor 1 (FGFR1) can regulate osteoblast activity and influence bone mass. So we explored the role of FGFR1 in EPC mobilization. Male mice with osteoblast-specific knockout of Fgfr1 (Fgfr1(fl/fl);OC-Cre) and its wild-type littermates (Fgfr1(fl/fl) ) were used in this study. Mice intraperitoneally injected with lipopolysaccharide (LPS) were used to measure the number of circulating EPCs in peripheral blood and serum stromal cell-derived factor 1α (SDF-1α). The circulating EPC number and the serum level of SDF-1α were significantly higher in Fgfr1(fl/fl);OC-Cre mice than those in Fgfr1(fl/fl) mice after LPS injection. In cell culture system, SDF-1α level was also significantly higher in Fgfr1(fl/fl);OC-Cre osteoblasts compared with that in Fgfr1(fl/fl) osteoblasts after LPS treatment. TRAP staining showed that there was no significant difference between the osteoclast activity of septic Fgfr1(fl/fl) and Fgfr1(fl/fl);OC-Cre mice. This study suggests that targeted deletion of Fgfr1 in osteoblasts enhances mobilization of EPCs into peripheral blood through up-regulating SDF-1α secretion from osteoblasts.

Fibroblastic growth factor receptor 1 amplification in osteosarcoma is associated with poor response to neo-adjuvant chemotherapy

Osteosarcoma, the most common primary bone sarcoma, is a genetically complex disease with no widely accepted biomarker to allow stratification of patients for treatment. After a recent report of one osteosarcoma cell line and one tumor exhibiting fibroblastic growth factor receptor 1 (FGFR1) gene amplification, the aim of this work was to assess the frequency of FGFR1 amplification in a larger cohort of osteosarcoma and to determine if this biomarker could be used for stratification of patients for treatment. About 352 osteosarcoma samples from 288 patients were analyzed for FGFR1 amplification by interphase fluorescence in situ hybridization. FGFR1 amplification was detected in 18.5% of patients whose tumors revealed a poor response to chemotherapy, and no patients whose tumors responded well to therapy harbored this genetic alteration. FGFR1 amplification is present disproportionately in the rarer histological variants of osteosarcoma. This study provides a rationale for inclusion of patients with osteosarcoma in clinical trials using FGFR kinase inhibitors.

MicroRNA-198 inhibits proliferation and induces apoptosis of lung cancer cells via targeting FGFR1

Lung cancer is the most common cause of death from cancer worldwide and recent studies have revealed that microRNAs play critical roles to regulate lung carcinogenesis. Here we present evidence to show the role of miR-198 in lung cancer development. Our results showed that ectopic expression of miR-198 inhibits the viability and induces the apoptosis of human non-small cell lung cancer cells A549 and NCI-H460, while miR-198 inhibition resulted in opposite changes. In nude mice miR-198 inhibits A549 growth of tumor graft. We further demonstrated that miR-198 directly targets fibroblast growth factor receptor 1 (FGFR1) in lung cancer cells. Restoring FGFR1 expression blocked the inhibitory function of miR-198, while FGFR1 inhibition achieved the similar phenotypes of miR-198 overexpression. Hence, our data delineates the molecular pathway by which miR-198 inhibits lung cancer cellular proliferation and induces apoptosis, and may have important implication for the treatment of lung carcinogenesis.

Investigation of FGF1 and FGFR gene polymorphisms in a group of Iranian patients with nonsyndromic cleft lip with or without cleft palate

OBJECTIVE

Nonsyndromic cleft lip with or without cleft palate (NS-CL/P) is one of the most common craniofacial malformations determined by the interaction between multiple genes and environmental risk factors. Genes coding for fibroblast growth factors and their receptors (FGF/FGFR genes) are considered as excellent candidate genes, which their proteins play important roles in craniofacial and palatal development. The aim of the current study was to assess the possible association between FGF1 rs34010 C>A and FGFR1 rs13317 A>G gene polymorphisms and susceptibility to NS-CL/P in an Iranian population.

DESIGN

This case-control retrospective study was performed on a total of 200 subjects including 100 NS-CL/P patients and 100 healthy unrelated controls. Tetra amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) was used to detect FGF1 rs34010 C>A and FGFR1 rs13317 A>G SNPs.

RESULTS

Our data demonstrated that the FGF1 rs34010, CA and CA+AA genotypes were associated with a reduced risk of NS-CL/P the in codominant (CA vs. CC: OR=0.29, 95%CI=0.16-0.55, P=0.001) and dominant (CA+AA vs. CC: OR=0.36, 95%CI=0.19-0.69, P=0.001) tested inheritance models, respectively. Additionally, the analysis of FGF1/FGFR1 genotype combinations revealed that rs34010CA/rs13317AA and rs34010CA/rs13317AG combinations were associated with a lower risk of NS-CL/P (OR=0.357, P=0.008 for the rs34010CA/rs13317AA; OR=0.226, P=0.004 for the rs34010CA/rs13317AG).

CONCLUSIONS

Our findings suggest that the FGF1 rs34010 C/A polymorphism was associated with a decreased risk of NS-CL/P, and might act as a protective factor against NS-CL/P predisposition.

NCAM and FGFR1 coexpression and colocalization in renal tumors

Neural cell adhesion molecule (NCAM) and fibroblast growth factor receptor (FGFR) have a role in epithelial-mesenchymal transformation during tumor genesis. Interplay between both molecules activates FGFR signaling and it could be responsible for tumor development. Renal epithelial tumors were analyzed for FGFR1 and NCAM coexpression by immunohistochemistry and for colocalization of these molecules on the particular tumor cells by triple immunofluorescence. Detection of NCAM isoforms in renal tumors was evaluated by RT-PCR. Applying immunohistochemistry we revealed that the majority of analyzed renal neoplasms, including renal cell carcinoma (RCC) and oncocytoma coexpressed NCAM and FGFR1. Triple immunofluorescent technique confirmed that both markers are commonly colocalized on the same tumor cells. Interestingly, it seemed that different position of NCAM and FGFR1 expression on renal tumor cells is related to renal tumor type or grade: exclusively membranous FGFR1/NCAM expression occurred in low grade clear cell RCC (cRCC); cytoplasmatic and membranous expression was present in high grade cRCC and other RCC types; oncocytoma showed only cytoplasmatic staining of both markers. NCAM-140 and NCAM-120 were detected in almost all analyzed renal neoplasms. Expression of both molecules on different cell compartments in various kidney tumors indicated that NCAM/FGFR1 interaction could play distinct roles in renal tumor genesis.

Systemic mastocytosis with associated myeloproliferative neoplasm with t(8;19)(p12;q13.1) and abnormality of FGFR1: report of a unique case

Systemic mastocytosis is a neoplastic proliferation of mast cells that frequently presents with associated clonal hematological non-mast cell lineage disease. Myeloid and lymphoid neoplasms with abnormalities of the FGFR1 gene are a heterogenous group of rare and aggressive hematopoietic stem cell disorders. About a dozen of chromosome changes involving the FGFR1 gene, presenting as myeloid or lymphoid neoplasms, have been described in the literature. To date, only 2 cases of myeloid and lymphoid neoplasms with abnormalities of the FGFR1 gene have been reported in association with systemic mastocytosis, one with t(8;13) and one with t(8;17) involving the FGFR1 gene. Here we describe another case of myeloproliferative neoplasm with chromosome translocation t(8;19) involving FGFR1 gene associated with systemic mastocytosis.

The Differential Diagnosis of Eosinophilia in Neoplastic Hematopathology

Eosinophilia in the peripheral blood is classified as primary (clonal) hematologic neoplasms or secondary (nonclonal) disorders, associated with hematologic or nonhematologic disorders. This review focuses on the categories of hematolymphoid neoplasms recognized by the 2008 World Health Organization Classification of Tumours and Haematopoietic and Lymphoid Tissues that are characteristically associated with eosinophilia. We provide a systematic approach to the diagnosis of these neoplastic proliferations via morphologic, immunophenotypic, and molecular-based methodologies, and provide the clinical settings in which these hematolymphoid neoplasms occur. We discuss recommendations that eosinophilia working groups have published addressing some of the limitations of the current classification scheme.

Elevated expression of SOX2 and FGFR1 in correlation with poor prognosis in patients with small cell lung cancer

OBJECTIVES

The central issue in this study is to investigate the expression of Sex determining region Y-BOX2 (SOX2) and fibroblast growth factor receptor 1 (FGFR1), evaluate their clinicopathological variables and prognostic significance in small cell lung cancer (SCLC).

METHODS

Specimens from 222 SCLC patients and 53 adjacent normal lung tissues were detected by the immunohistochemistry for SOX2 and FGFR1 expression. The relationship between the expression of both markers and survival status was determined.

RESULTS

Overexpression of SOX2 and FGFR1 were revealed in SCLC tumors than in normal tissues (P<0.05). SOX2 expression was associated with clinical stage (P=0.014) and lymph node status (P=0.041). Besides, FGFR1 expression was significantly higher in ever smokers (P=0.030) and late stage SCLC (P=0.005). SOX2, FGFR1 and TNM stage were independent prognostic factors for overall survival (OS) and Recurrence-free survival (RFS) by multivariate analysis. In stage I patients, only overexpression of SOX2, but not of FGFR1, predicted poor OS (0.027) and RFS (P=0.013). According to the expression of SOX2 and FGFR1, patients were categorized into three groups. Patients with elevated expression of both markers belonged to the group with the shortest RFS (P<0.0001) and OS (P<0.0001).

CONCLUSIONS

Increased expression of SOX2 and FGFR1 may be available as poor prognostic indicators in SCLC patients.

High rate of FGFR1 amplifications in brain metastases of squamous and non-squamous lung cancer

OBJECTIVES

FGFR1 amplifications are common in squamous cell carcinoma and rare in adenocarcinoma of the lung, but have not been investigated in brain metastases of non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

We performed fluorescent in situ hybridization (FISH) for FGFR1 and immunohistochemistry for pAKT, PI3K, HIF1a and Ki67 in 175 NSCLC brain metastases and 11 matched primary tumors. ALK gene rearrangement status was available from a previous study. We performed statistical correlations of clinical, histopathological and molecular data.

RESULTS

FGFR1 amplifications were found in a total of 30/175 (17%) brain metastases: 4/21 (19%) squamous cell carcinomas, 20/130 (15.3%) adenocarcinomas, 2/12 (16.6%) adenosquamous carcinomas, 4/9 (44.4%) large cell carcinomas and 0/3 neuroendocrine large cell carcinoma. FGFR1 gene status was identical between primary tumors and brain metastases in 9/11 evaluable cases. In 2/11 cases (1 adenosquamous and 1 large cell carcinoma), FGFR1 amplifications were present only in the brain metastasis and not in the primary tumor. Furthermore, we found a significant positive correlation of ALK and FGFR1 gene amplification status in brain metastases (p<0.001, Chi square test). Patients with high-level FGFR1 amplifications had significantly higher number of visceral metastases (p<0.001, Chi square test).

CONCLUSION

Our findings argue for an enrichment of FGFR1 amplifications in brain metastases of adenocarcinomas (where they were 5-fold more frequent than reported for primary tumors) and possibly also of other non-squamous carcinomas, but not in squamous cell carcinomas of the lung. These results may be relevant for targeted therapy and prophylaxis of NSCLC brain metastases.

Structural insights into the interaction of human S100B and basic fibroblast growth factor (FGF2): Effects on FGFR1 receptor signaling

S100B is a calcium sensing protein belonging to the S100 protein family with intracellular and extracellular roles. It is one of the EF hand homodimeric proteins, which is known to interact with various protein targets to regulate varied biological functions. Extracellular S100B has been recently reported to interact with FGF2 in a RAGE-independent manner. However, the recognition mechanism of S100B-FGF2 interaction at the molecular level remains unclear. In this study, the critical residues on S100B-FGF2 interface were mapped by combined information derived from NMR spectroscopy and site directed mutagenesis experiments. Utilizing NMR titration data, we generated the structural models of S100B-FGF2 complex from the computational docking program, HADDOCK which were further proved stable during 15ns unrestrained molecular dynamics (MD) simulations. Isothermal titration calorimetry studies indicated S100B interaction with FGF2 is an entropically favored process implying dominant role of hydrophobic contacts at the protein-protein interface. Residue level information of S100B interaction with FGF2 was useful to understand the varied target recognition ability of S100B and further explained its role in effecting extracellular signaling diversity. Mechanistic insights into the S100B-FGF2 complex interface and cell-based assay studies involving mutants led us to conclude the novel role of S100B in FGF2 mediated FGFR1 receptor inactivation.

Matrix metalloproteinase-2 deletions protect against hemorrhagic transformation after 1 h of cerebral ischemia and 23 h of reperfusion

Although elevated matrix metalloproteinase (MMP)-2 levels were highly related to the degradation of tight junction (TJ) proteins and basal lamina and neuronal injury after ischemia, until very recently, little experimental evidence was available to test the role of the MMP-2 knockout (KO) in blood-brain-barrier (BBB) injury and the development of hemorrhage transformation (HT). Here, we assessed the role of the MMP-2 KO in BBB injury, HT and other brain injuries after 1h of ischemia and 23 h of reperfusion. Middle cerebral artery occlusion (MCAO) was performed in MMP-2 KO mice. Reperfusion was started 1h after the onset of MCAO. All mice were sacrificed 24h after the MCAO. MMP-2 deficiency reduced the decrease in protein levels of collagen IV and cellular membrane occludin (p<0.01 and 0.05 vs. wild-type (WT), respectively) and attenuated increase in cytosol occludin level in ischemic brain (p<0.01 vs. WT). The hemorrhage volume and brain infarction were significantly decreased in both the cortex and striatum in the MMP-2 KO mice (p<0.01 vs. WT). The MMP-2 KO also had reduced brain swelling in the cortex and improved neurological deficits (p<0.01 vs. WT). These studies provide direct evidence that targeting MMP-2 will effectively protect against collagen and occludin loss and HT after ischemia and reperfusion.

Targeting genomic alterations in squamous cell lung cancer

Squamous cell lung cancer causes approximately 400,000 deaths worldwide per year. Identification of specific molecular alterations, such as activating mutations in the epidermal growth factor receptor kinase and echinoderm microtubule-associated protein-like 4/anaplastic lymphoma kinase fusions have led to significant therapeutic gains in patients with adenocarcinoma. However, meaningful therapeutic gains based on the molecular pathobiology of squamous cell lung cancer have not yet been realized. A comprehensive genomic characterization of 178 cases of squamous cell lung cancer has recently been reported. Squamous cell lung cancer appears to be characterized by a broader and more complex group of genomic alterations than adenocarcinoma. In this review, potentially targetable genes or pathways in squamous cell lung cancer are emphasized in relation to available therapeutic agents in development or active clinical trials. This organization of data will provide a framework for development for clinical investigation. Squamous cell lung cancer appears to be characterized by not only driver mutations in candidate genes but also gene copy number alterations resulting in tumor proliferation and survival. Better understanding of these genetic alterations and their use as therapeutic targets will require broad collaboration between industry, government, the cooperative groups, and academic institutions with the ultimate goal of rapid translation of scientific advancement to patient benefit.

The unique expression and function of miR-424 in human placental trophoblasts

Placental hypoperfusion causes cellular hypoxia and is associated with fetal growth restriction and preeclampsia. In response to hypoxia, the repertoire of genes expressed in placental trophoblasts changes, which influences key cellular processes such as differentiation and fusion. Diverse miRNAs were recently found to modulate the cellular response to hypoxia. Here we show that miR-424, which was previously shown to be upregulated by hypoxia in nontrophoblastic cell types, is uniquely downregulated in primary human trophoblasts by hypoxia or chemicals known to hinder cell differentiation. We also identify FGFR1 as a direct target of miR-424 in human trophoblasts. This effect is unique to miR-424 and is not seen with other members of this miRNA family that are expressed in trophoblasts, such as miR-15 and miR-16. Our findings establish a unique role for miR-424 during differentiation of human trophoblasts.

Olfactory system and demyelination

Within the central nervous system, the olfactory system represents one of the most exciting scenarios since it presents relevant examples of long-life sustained neurogenesis and continuous axonal outgrowth from the olfactory epithelium with the subsequent plasticity phenomena in the olfactory bulb. The olfactory nerve is composed of nonmyelinated axons with interesting ontogenetic interpretations. However, the centripetal projections from the olfactory bulb are myelinated axons which project to more caudal areas along the lateral olfactory tract. In consequence, demyelination has not been considered as a possible cause of the olfactory symptoms in those diseases in which this sense is impaired. One prototypical example of an olfactory disease is Kallmann syndrome, in which different mutations give rise to combined anosmia and hypogonadotropic hypogonadism, together with different satellite symptoms. Anosmin-1 is the extracellular matrix glycoprotein altered in the X-linked form of this disease, which participates in cell adhesion and migration, and axonal outgrowth in the olfactory system and in other regions of the central nervous system. Recently, we have described a new patho-physiological role of this protein in the absence of spontaneous remyelination in multiple sclerosis. In the present review, we hypothesize about how both main and satellite neurological symptoms of Kallmann syndrome may be explained by alterations in the myelination. We revisit the relationship between the olfactory system and myelin highlighting that minor histological changes should not be forgotten as putative causes of olfactory malfunction.