Multiple roles of extracellular fibroblast growth factors in lung cancer cells

Aptamers against cancer drug resistance: Small fighters switching tactics in the face of defeat

Discovering novel cancer therapies has attracted extreme interest in the last decade. In this regard, multidrug resistance (MDR) to chemotherapies is the primary challenge in cancer treatment. Cancerous cells are growingly become resistant to existing chemotherapeutics by employing diverse mechanisms, highlighting the significance of discovering approaches to overcome MDR. One promising strategy is utilizing aptamers as unique tools to target elements or signalings incorporated in resistance mechanisms or develop active targeted drug delivery systems or chimeras enabling the precise delivery of novel agents to inhibit the conventionally undruggable resistance elements. Further, due to their advantages over their proteinaceous counterparts, particularly antibodies, including improved targeting action, enhanced thermal stability, easier production, and superior tumor penetration, aptamers are emerging and have frequently been considered for developing cancer therapeutics. Here, we highlighted significant chemoresistance pathways and thoroughly discussed using aptamers as prospective tools to surmount cancer MDR.

[Research Progress on the Pathogenesis of Lung Cancer Associated with Idiopathic Pulmonary Fibrosis]

Idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung disease (ILD) of unknown causes, which is characterized by pulmonary fibrosis. The median survival period after diagnosis is about 2-4 years. In recent years, the incidence rate of lung cancer associated with IPF (IPF-LC) is increasing, and the prognosis is worse than that of IPF alone. Pulmonary fibrosis may be closely associated with the occurrence and development of lung cancer. Although the pathogenesis of IPF-LC is still unclear, the current research shows that there are similarities between the pathogenesis of these two diseases at molecular and cellular levels. At present, the research on the cellular and molecular mechanism of lung cancer related to pulmonary fibrosis has become the focus of researchers' attention. This article reviews the related literature, focusing on the latest status of the cellular and molecular mechanisms and treatment of IPF-LC, hoping to help clinicians understand IPF-LC.
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Identification of circRNA-miRNA-Immune-Related mRNA Regulatory Network in Gastric Cancer

The pathogenesis of gastric cancer (GC) is still not fully understood. We aimed to find the potential regulatory network for ceRNA (circRNA–miRNA–immune-related mRNA) to uncover the pathological molecular mechanisms of GC. The expression profiles of circRNA, miRNA, and mRNA in gastric tissue from GC patients were downloaded from the Gene Expression Omnibus (GEO) datasets. Differentially expressed circRNAs, miRNAs, and immune-related mRNAs were filtered, followed by the construction of the ceRNA (circRNA–miRNA–immune-related mRNA) network. Functional annotation and protein–protein interaction (PPI) analysis of immune-related mRNAs in the network were performed. Expression validation of circRNAs and immune-related mRNAs was performed in the new GEO and TCGA datasets and in-vitro experiment. A total of 144 differentially expressed circRNAs, 216 differentially expressed miRNAs, and 2,392 differentially expressed mRNAs were identified in GC. Some regulatory pairs of circRNA–miRNA–immune-related mRNA were obtained, including hsa_circ_0050102–hsa-miR-4537–NRAS–Tgd cells, hsa_circ_0001013–hsa-miR-485-3p–MAP2K1–Tgd cells, hsa_circ_0003763–hsa-miR-145-5p–FGF10–StromaScore, hsa_circ_0001789–hsa-miR-1269b–MET–adipocytes, hsa_circ_0040573–hsa-miR-3686–RAC1–Tgd cells, and hsa_circ_0006089–hsa-miR-5584-3p–LYN–neurons. Interestingly, FGF10, MET, NRAS, RAC1, MAP2K1, and LYN had potential diagnostic value for GC patients. In the KEGG analysis, some signaling pathways were identified, such as Rap1 and Ras signaling pathways (involved NRAS and FGF10), Fc gamma R-mediated phagocytosis and cAMP signaling pathway (involved RAC1), proteoglycans in cancer (involved MET), T-cell receptor signaling pathway (involved MAP2K1), and chemokine signaling pathway (involved LYN). The expression validation of hsa_circ_0003763, hsa_circ_0004928, hsa_circ_0040573, FGF10, MET, NRAS, RAC1, MAP2K1, and LYN was consistent with the integrated analysis. In conclusion, the identified ceRNA (circRNA–miRNA–immune-related mRNA) regulatory network may be associated with the development of GC.

Anti-Cancer Effect of Cordycepin on FGF9-Induced Testicular Tumorigenesis

Cordycepin, a bioactive constituent from the fungus Cordyceps sinensis, could inhibit cancer cell proliferation and promote cell death via induction of cell cycle arrest, apoptosis and autophagy. Our novel finding from microarray analysis of cordycepin-treated MA-10 mouse Leydig tumor cells is that cordycepin down-regulated the mRNA levels of FGF9, FGF18, FGFR2 and FGFR3 genes in MA-10 cells. Meanwhile, the IPA-MAP pathway prediction result showed that cordycepin inhibited MA-10 cell proliferation by suppressing FGFs/FGFRs pathways. The in vitro study further revealed that cordycepin decreased FGF9-induced MA-10 cell proliferation by inhibiting the expressions of p-ERK1/2, p-Rb and E2F1, and subsequently reducing the expressions of cyclins and CDKs. In addition, a mouse allograft model was performed by intratumoral injection of FGF9 and/or intraperitoneal injection of cordycepin to MA-10-tumor bearing C57BL/6J mice. Results showed that FGF9-induced tumor growth in cordycepin-treated mice was significantly smaller than that in a PBS-treated control group. Furthermore, cordycepin decreased FGF9-induced FGFR1-4 protein expressions in vitro and in vivo. In summary, cordycepin inhibited FGF9-induced testicular tumor growth by suppressing the ERK1/2, Rb/E2F1, cell cycle pathways, and the expressions of FGFR1-4 proteins, suggesting that cordycepin can be used as a novel anticancer drug for testicular cancers.

Mechanisms of Multidrug Resistance in Cancer Chemotherapy

Cancer is one of the main causes of death worldwide. Despite the significant development of methods of cancer healing during the past decades, chemotherapy still remains the main method for cancer treatment. Depending on the mechanism of action, commonly used chemotherapeutic agents can be divided into several classes (antimetabolites, alkylating agents, mitotic spindle inhibitors, topoisomerase inhibitors, and others). Multidrug resistance (MDR) is responsible for over 90% of deaths in cancer patients receiving traditional chemotherapeutics or novel targeted drugs. The mechanisms of MDR include elevated metabolism of xenobiotics, enhanced efflux of drugs, growth factors, increased DNA repair capacity, and genetic factors (gene mutations, amplifications, and epigenetic alterations). Rapidly increasing numbers of biomedical studies are focused on designing chemotherapeutics that are able to evade or reverse MDR. The aim of this review is not only to demonstrate the latest data on the mechanisms of cellular resistance to anticancer agents currently used in clinical treatment but also to present the mechanisms of action of novel potential antitumor drugs which have been designed to overcome these resistance mechanisms. Better understanding of the mechanisms of MDR and targets of novel chemotherapy agents should provide guidance for future research concerning new effective strategies in cancer treatment.

Idiopathic Pulmonary Fibrosis and Lung Cancer: Mechanisms and Molecular Targets

Idiopathic pulmonary fibrosis (IPF) is the most common idiopathic interstitial pulmonary disease with a median survival of 2–4 years after diagnosis. A significant number of IPF patients have risk factors, such as a history of smoking or concomitant emphysema, both of which can predispose the patient to lung cancer (LC) (mostly non-small cell lung cancer (NSCLC)). In fact, IPF itself increases the risk of LC development by 7% to 20%. In this regard, there are multiple common genetic, molecular, and cellular processes that connect lung fibrosis with LC, such as myofibroblast/mesenchymal transition, myofibroblast activation and uncontrolled proliferation, endoplasmic reticulum stress, alterations of growth factors expression, oxidative stress, and large genetic and epigenetic variations that can predispose the patient to develop IPF and LC. The current approved IPF therapies, pirfenidone and nintedanib, are also active in LC. In fact, nintedanib is approved as a second line treatment in NSCLC, and pirfenidone has shown anti-neoplastic effects in preclinical studies. In this review, we focus on the current knowledge on the mechanisms implicated in the development of LC in patients with IPF as well as in current IPF and LC-IPF candidate therapies based on novel molecular advances.

miR-4317 suppresses non-small cell lung cancer (NSCLC) by targeting fibroblast growth factor 9 (FGF9) and cyclin D2 (CCND2)

Background

Non-small cell lung cancer (NSCLC) is a leading cause of death worldwide. MicroRNAs (miRNAs) have been indicated as crucial actors in cancer biology. Accumulating evidence suggests that miRNAs can be used as diagnostic and prognostic markers for NSCLC.

Methods

The purpose of this study was to characterize and identify the novel biomarker miR-4317 and its targets in NSCLC. The expression of miR-4317 was analyzed by in situ hybridization (ISH) and quantitative reverse transcription polymerase chain reaction (qRT-PCR). The effect of miR-4317 on proliferation was evaluated through 3–4,5-dimethylthiazol-2-yl-5-3–carboxymethoxyphenyl-2-4-sulfophenyl-2H-tetrazolium (MTS) and colony formation assays, and cell migration and invasion were evaluated through transwell assays. The expression of target proteins and downstream molecules was analyzed by qRT-PCR and western blot. Dual-luciferase reporter assay was used to assess the target genes of miR4317 in NSCLC cells.

Results

Our results demonstrated that miR-4317 was downregulated in NSCLC tissues and serum, particularly in lymph node metastasis and advanced clinical stage tissues. Kaplan-Meier survival analysis showed that NSCLC patients with high expression of miR-4317 exhibited better overall survival (OS). Enhanced expression of miR-4317 significantly inhibited proliferation, colony formation, migration and invasion, and hampered cycles of NSCLC cell lines in vitro. Our results suggested that miR-4317 functions by directly targeting fibroblast growth factor 9 (FGF9) and cyclin D2 (CCND2). In concordance with in vitro studies, mouse xenograft, lung, and brain metastatic studies validated that miR-4317 functions as a potent suppressor miRNA of NSCLC in vivo. Systemically delivered agomiR-4317 reduced tumor growth and inhibited FGF9 and CCND2 protein expression. Reintroduction of FGF9 and CCND2 attenuated miR-4317-mediated suppression of migration and invasion in NSCLC.

Conclusions

Our results indicate that miR-4317 can reduce NSCLC cell growth and metastasis by targeting FGF9 and CCND2. These findings provide new evidence of miR-4317 as a potential non-invasive biomarker and therapeutic target for NSCLC.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0882-4) contains supplementary material, which is available to authorized users.

FGF4 induces epithelial-mesenchymal transition by inducing store-operated calcium entry in lung adenocarcinoma

Several fibroblast growth factor (FGF) isoforms act to stimulate epithelial-mesenchymal transition (EMT) during cancer progression. FGF4 and FGF7 are two ligands of FGF receptor 2 (FGFR2). Using two lung adenocarcinoma (ADC) cell lines, A549 and H1299, we showed that FGF4, but not FGF7, altered cell morphology, promoted EMT-associated protein expression, and enhanced cell proliferation, migration/invasion and colony initiation. In addition, FGF4 increased store-operated calcium entry (SOCE) and expression of the calcium signal-associated protein Orai1. The SOCE inhibitor 2,5-di-tert-butylhydroquinone (BHQ) or Orai1 knockdown reversed all of the EMT-promoting effects of FGF4. BHQ also inhibited FGF4-induced EMT in a mouse xenograft model. Finally, 60 human lung ADC samples and 21 sets of matched specimens (primary and metastatic foci in lymph nodes from one patient) were used to confirm the clinicopathologic significance of FGF4 and its correlation with E-cadherin, Vimentin and Orai1 expression. Our study thus shows that FGF4 induces EMT by elevating SOCE in lung ADC.

The anti-apoptotic and prognostic value of fibroblast growth factor 9 in gastric cancer

Fibroblast growth factor (FGF) 9 is a member of the FGF family, which promotes carcinogenesis in some solid tumours. However, its biological and prognostic significance in gastric cancer (GC) is unclear. We examined FGF9 expression in 180 GC and corresponding non-tumorous gastric tissue samples by immunohistochemistry and evaluated its role in predicting tumour prognosis. Knockdown of FGF9 by siRNA inhibited cell growth and induced apoptosis in GC cell lines. Fifty of the 180 GC specimens (27.8%) had high FGF9 protein expression, whereas decreased or unchanged expression was observed in 130 cases (72.2%). High FGF9 expression was a significant predictor of poor survival (28.1 vs. 55.8 months, P < 0.001). After stratification according to AJCC stage, FGF9 remained a significant predictor of shorter survival in stage II (30.6 vs. 64.9 months, P < 0.001) and stage III GC (29.7 vs. 58.9 months, P < 0.001). Multivariate and univariate analysis showed that higher expression of FGF9 can be used as a predictor for poor prognosis (HR, 2.95; 95% CI, 1.97–4.41; P < 0.001; and HR, 2.94; 95% CI, 2.01–4.31; P < 0.001, respectively). FGF9 may provide the anti-apoptotic function and be useful as a novel independent marker for evaluating GC prognosis

FGF2 promotes metastasis of uveal melanoma cells via store-operated calcium entry

Uveal melanoma (UM), the most common primary intraocular malignancy in adults, is highly metastatic and associated with dismal prognosis. Fibroblast growth factor 2 (FGF2) has been shown to induce cell proliferation and angiogenesis of melanoma and other malignancies. However, the expression of FGF2 in UM and its effects on melanoma cell migration are not well known. In this study, we found FGF2 expression was related to UM histological subtype and presence of metastasis. In vitro experiments showed that FGF2 treatment caused increased horizontal and vertical migration and F-actin cytoskeleton assembly as well as decreased adhesive activity of MUM2B cells, together with increased intracellular calcium concentration and expression of ORAI1 and STIM1 – two key regulatory proteins of store-operated calcium entry (SOCE). The mouse xenograft model showed that MUM2B cells with FGF2 stimulation grew into larger tumor masses and were prone to metastasis. In addition, the SOCE inhibitor 2-aminoethoxydiphenyl borate (2-APB) reversed all of these effects of FGF2. Finally, human UM samples and mouse xenograft model samples were used to confirm the correlation of FGF2 with ORAI1 and STIM1 expression. Taken together, our study suggests that FGF2 promotes metastasis of UM via SOCE.

Gubenyiliu II Inhibits Breast Tumor Growth and Metastasis Associated with Decreased Heparanase Expression and Phosphorylation of ERK and AKT Pathways

Gubenyiliu II (GYII), a Traditional Chinese Medicine (TCM) formula used in our hospital, has shown beneficial effects in cancer patients. In this study, we investigated the molecular mechanisms underlying the beneficial effects of GYII on murine breast cancer models. GYII showed significant inhibitory effects on tumor growth and metastasis in the murine breast cancer model. Additionally, GYII suppressed the proliferation of 4T1 and MCF-7 cells in a dose-dependent manner. A better inhibitory effect on 4T1 cell proliferation and migration was found in the decomposed recipes (DR) of GYII. Moreover, heparanase expression and the degree of angiogenesis were reduced in tumor tissues. Western blot analysis showed decreased expression of heparanase and growth factors in the cells treated with GYII and its decomposed recipes (DR2 and DR3), and thereby a reduction in the phosphorylation of extracellular signal-regulated kinase (ERK) and serine-threonine kinase (AKT). These results suggest that GYII exerts anti-tumor growth and anti-metastatic effects in the murine breast cancer model. The anti-tumor activity of GYII and its decomposed recipes is, at least partly, associated with decreased heparanase and growth factor expression, which subsequently suppressed the activation of the ERK and AKT pathways.

FGF9 and FGF18 in idiopathic pulmonary fibrosis promote survival and migration and inhibit myofibroblast differentiation of human lung fibroblasts in vitro

Idiopathic pulmonary fibrosis (IPF) is characterized by an accumulation of extracellular matrix proteins and fibroblasts in the distal airways. Key developmental lung signaling pathways are reactivated in IPF. For instance, fibroblast growth factor 9 (FGF9) and FGF18, involved in epithelial-mesenchymal interactions, are critical for lung development. We evaluated the expression of FGF9, FGF18, and FGF receptors (FGFRs) in lung tissue from controls and IPF patients and assessed their effect on proliferation, survival, migration, and differentiation of control and IPF human lung fibroblasts (HLFs). FGF9, FGF18, and all FGFRs were present in the remodeled alveolar epithelium close to the fibroblast foci in IPF lungs. FGFR3 was generally detected in fibroblast foci by immunohistochemistry. In vitro, HLFs mainly expressed mesenchyme-associated FGFR isoforms (FGFR1c and FGFR3c) and FGFR4. FGF9 did not affect fibroblast proliferation, whereas FGF18 inhibited cell growth in control fibroblasts. FGF9 and FGF18 decreased Fas-ligand-induced apoptosis in control but not in IPF fibroblasts. FGF9 prevented transforming growth factor β1-induced myofibroblast differentiation. FGF9 and FGF18 increased the migratory capacities of HLF, and FGF9 actively modulated matrix metalloproteinase activity. In addition, FGFR3 inhibition by small interfering RNA impacted p-ERK activation by FGF9 and FGF18 and their effects on differentiation and migration. These results identify FGF9 as an antiapoptotic and promigratory growth factor on HLF, maintaining fibroblasts in an undifferentiated state. The biological effects of FGF9 and FGF18 were partially driven by FGFR3. FGF18 was a less potent molecule. Both growth factors likely contribute to the fibrotic process in vivo.